WO2007033334A2

WO2007033334A2 - Testing compositions in a corrosive environment

Info

Publication number: WO2007033334A2
Application number: PCT/US2006/035872
Authority: WO
Inventors: H. Sam Bergh; Stephen Cypes; Damian Hajduk; Zach Hogan; Richard Tiede
Original assignee: Symyx Technologies, Inc
Priority date: 2005-09-14
Filing date: 2006-09-14
Publication date: 2007-03-22
Also published as: WO2007033334A3

Abstract

Methods, apparatus and systems implementing techniques for screening compositions in a test environment. Test samples are exposed to one or more test fluids under controlled conditions. The test samples and/or test fluids are analyzed to detect an effect of the exposure.

Description

TESTING COMPOSITIONS IN A CORROSIVE ENVIRONMENT

BACKGROUND

[0001 ] This invention relates to techniques for screening for the effects of exposing samples to a test environment.

[0002] Chemical processes often involve the exposure of process infrastructure such as metal reactors, vessels, pipelines and the like, to corrosive environments. A number of techniques have been developed to detect and quantify corrosion of metal materials. However, these techniques typically focus on long term measurements, and require large amounts of both the metal samples and the fluids being tested. One particular technique involves the production of high shear at the surface of a metal coupon by directing a jet of liquid at the coupon's surface. The shear produced using this technique is highly variable, particularly at points far from the point at which the jet impinges upon the coupon surface, and is dependent on a variety of conditions, such as the nozzle used, fluid pressure, and the like. Other techniques involve batch autoclave experiments that have typically not accurately reproduced the high wall shear stress that is typically found in pipelines carrying high velocity and/or turbulent flow, and thus may not accurately simulate real-world corrosion conditions.

SUMMARY

[0003] The invention provides methods and systems implementing techniques for testing how materials respond to environmental exposures, hi general, in one aspect, the invention features methods, apparatus and systems implementing techniques for screening compositions in a test environment. The techniques include positioning one or more test samples in a flow channel, exposing the test samples to a reciprocating flow of a test fluid in the flow channel under controlled wall-shear conditions, and detecting an effect of the exposing on the test samples.

[0004] Particular embodiments can include one or more of the following features. Positioning the test samples can include positioning a plurality of different test samples in the flow channel. The plurality of different test samples can differ based on then- constituent materials, coatings and/or surface treatments. The test samples can include one or more metals. The test samples can include one or more coatings or films. The test samples can include one or more materials used in a refinery process. Exposing the test samples can include exposing a surface of each of the one or more test samples to the reciprocating fluid flow. Exposing the test samples can include heating at least a portion of the flow channel. Exposing the test samples can include controlling wall-shear conditions by controlling a pressure within the flow channel, such as by pumping the test fluid using a syringe pump or a diaphragm pump to provide the reciprocating fluid flow. The test fluid can include a crude oil or crude oil fraction.

[0005] Detecting an effect can include analyzing the test samples - for example, analyzing the test samples for changes in a surface property or weight of the test samples - or analyzing the test fluid - for example, analyzing the test fluid for the presence of elements or ions or a change in pH. Positioning the test samples can include positioning one or more test samples in each of a plurality of flow channels. Exposing the test samples can include exposing the test samples in each the plurality of flow channels to a reciprocating flow of one or more test fluids under controlled pressure conditions. Positioning the test samples can include positioning a different test sample in each of the plurality of flow channels. Exposing the test samples can include exposing the test samples in each of the plurality of flow channels to a reciprocating flow of a different test fluid under controlled pressure conditions.

[0006] In general, in another aspect, the invention features methods, apparatus and systems implementing techniques for screening compositions in a test environment. The techniques include providing a sample array including a substrate and a plurality of test samples mounted in or on the substrate, providing a fluid array including a plurality of wells, each of the plurality of wells containing a test fluid, immersing the test samples in the fluid array wells to expose a surface of each of the test samples to the test fluids, moving the sample array relative to the fluid array while maintaining a defined relationship between the test sample surfaces and bottom surfaces, and detecting an effect of the moving on the test samples or the test fluids.

[0007] Particular embodiments can include one or more of the following features. The sample array can include a plurality of different test samples. The test samples can include one or more metals. The test samples can include one or more coatings or films. The test samples can include one or more materials used in a refinery process. The fluid array can include a plurality of different test fluids. The test fluids can include one or more crude oils or crude oil fractions. One or more side surfaces of the test samples, and the internal surfaces of the array wells, can be coated with one or more inert materials. [0008] Moving the sample array relative to the fluid array can include moving the sample array relative to the fluid array while maintaining a defined gap between the test surfaces and the bottom surfaces to create a controlled wall shear stress at the test surface, and detecting can include detecting an effect of the wall shear stress on the test samples. Moving the sample array relative to the fluid array can include moving the sample array relative to the fluid array while maintaining contact between the test surfaces and the bottom surfaces, and detecting can include detecting an effect of friction and/or wear on the test samples. Moving the sample array can include moving the sample array in an orbital pattern about an axis perpendicular to the bottom surfaces of the fluid array. Detecting an effect can include analyzing the test surfaces and/or the test fluids for changes resulting from the moving.

[0009] In general, in still another aspect, the invention features methods, apparatus and systems implementing techniques for screening compositions in a test environment. The techniques include positioning a test sample in a each of a plurality of test cells, depositing a test fluid in each of the plurality of test cells, positioning a shuttle in each of the plurality of test cells, the shuttles defining a flow region along a surface of the test samples, moving each of the shuttles in the corresponding test cells to force a flow of the corresponding test fluid through the flow region, and detecting an effect of the test fluid flow on the test samples.

[0010] Particular embodiments can include one or more of the following features. The test samples can include one or more metals. The test samples can include one or more coatings or films. The test samples can include one or more materials used in a refinery process. The test fluid can include a crude oil or crude oil fraction. The techniques can include heating at least a portion of the test cells during the moving. The shuttles can be positioned around the test samples to define the flow region as an annular space around each of the test samples. The shuttles can be moved in a reciprocating motion from a first end of the test cells to a second end of the test cells, and back. Moving the shuttles can include driving the test shuttles by magnetic coupling. Detecting an effect can include analyzing the test samples - for example,analyzing the test samples for changes in a surface property or weight - or analyzing the test fluid - for example, analyzing the test fluid for the presence of elements or ions or a change in pH. A different test fluid and/or a different test sample can be deposited in two or more of the plurality of test cells. The plurality of test cells can include a collection of test cells arranged in a reactor block. The plurality of test cells can include a plurality of collections of test cells, each collection being arranged in one of a plurality of reactor blocks. The test cells can be heated during the screening.

[0011] hi general, in still another aspect, the invention features methods, apparatus and systems implementing techniques for screening compositions in a test environment. The techniques include providing an array including a substrate and a plurality of test samples mounted in or on the substrate, each of the test samples having a test surface, exposing the test surface of each of the plurality of test samples to a test environment, and examining the test surface of each of the plurality of test samples by using a profilometry technique to detect changes resulting from exposure to the test environment.

[0012] Particular embodiments can include one or more of the following features. The array can include a plurality of test samples each including a different material. The test samples can include a plurality of test samples including the same material. The test samples can include one or more metals. The test samples can include one or more test samples having test surfaces formed by one or more coatings or films. The array can inclμde one or more standard samples mounted in or on the substrate, and examining the test surfaces includes comparing the test surfaces to standard surfaces. Examining the test surfaces can include comparing the test surfaces to a substrate surface. Exposing the test surface of each of the plurality of test samples to a test environment can include exposing two or more of the plurality of test surfaces to different test environments. Exposing the test surfaces can include exposing the test surfaces to a static or dynamic gas phase or liquid phase environment. Exposing the test surfaces can include stirring a liquid in contact with one or more of the test surfaces. Exposing the test surfaces can include transporting a gas or liquid across one or more of the test surfaces by bulk flow. Exposing the test surfaces includes transporting a gas or liquid across one or more of the test surfaces by reciprocating flow. Exposing the test surfaces can include immersing the test surfaces in the test environment and moving the test surfaces in an orbital motion relative to the test environment. [0013] Examining the test surfaces can include measuring a height difference or a roughness for each of the test samples. Examining the test surfaces can include examining the test surfaces using a optical or contact profilometry. Examining the test surfaces can include examining the test surfaces using atomic force microscopy or scanning electron microscopy.

[0014] In general, in another aspect, the invention features a system for screening compositions in a test environment. The system includes a flow channel defining a flow path for a test fluid, a sample holder for positioning a test sample in the flow path, a pumping subsystem configured to provide for a reciprocating constant pressure-driven flow past a test sample positioned in the flow path, and a temperature control subsystem configured to heat the test fluid to a desired temperature in a region of the flow channel adjacent to the sample holder.

[0015] Particular embodiments can include one or more of the following features. The sample holder can be configured to position a plurality of test samples in the flow channel. The test samples can differ based on their constituent materials, coatings and/or surface treatments. The test samples can include one or more materials used in a refinery process. The pumping subsystem can include a pair of syringe pumps or diaphragm pumps. The test fluid can include a crude oil or crude oil fraction. The system can include an analysis subsystem for detecting an effect of exposure of the test samples to the test fluid. The analysis subsystem can be operable to analyze the test samples for changes resulting from the exposure. The analysis subsystem can include a profϊlometer. The analysis subsystem can be operable to analyze the test fluid for changes resulting from the exposure. The analysis subsystem can include an inductively coupled plasma spectrometer or an atomic absorption spectrometer. [0016] The can include a plurality of flow channels defining flow paths for a plurality of test fluids and a plurality of sample holders for positioning test samples in the plurality of flow paths. The pumping subsystem can be configured to provide for a reciprocating constant pressure-driven flow past test samples positioned in each of the plurality of flow paths. A different test sample and/or a different test fluid can be positioned in two or more of the flow channels. The pumping subsystem can include a pair of syringe pumps or diaphragm pumps in communication with each of the plurality of flow paths. [0017] In general, in another aspect, the invention features a system for screening compositions in a test environment. The system includes a fluid array including a plurality of wells, each of the plurality of wells containing a test fluid, a sample array including a substrate and a plurality of test samples mounted in or on the substrate, each of the test samples having a test surface, the test samples being immersed in the fluid array wells to expose the test surfaces to the test fluids, the test samples and fluid array wells being positioned to define a spatial relationship between each test surface and a bottom surface of the corresponding well, a motion subsystem operable to move the sample array relative to the fluid array while maintaining the spatial relationship between the test surfaces and bottom surfaces, and a detector for detecting an effect of the moving on the test samples or the test fluids.

[0018] Particular embodiments can include one or more of the following features. The sample array can include a plurality of different test samples. The test samples can include. one or more metals. The test samples can include one or more coatings or films. The test samples can include one or more materials used in a refinery process. The fluid array can include a plurality of different test fluids. The test fluids can include one or more crude oils or crude oil fractions. One or more side surfaces of the test samples, and the internal surface of the test wells, can be coated with one or more inert materials. The motion subsystem can be operable to move the sample array relative to the fluid array while maintaining a defined gap between the test surfaces and the bottom surfaces to create a controlled wall shear stress at the test surface. The motion subsystem can be operable to move the sample array relative to the fluid array while maintaining a contact between the test surfaces and the bottom surfaces to create friction and/or wear at the test surface. The motion subsystem can be operable to move the sample array in an orbital pattern about an axis perpendicular to the bottom surfaces of the fluid array. [0019] The system can include an analysis subsystem for detecting an effect of exposure of the test samples to the test fluids. The analysis subsystem can be operable to analyze the test samples for changes resulting from the exposure. The analysis subsystem can include a profilometer. The analysis subsystem can be operable to analyze the test fluid for changes resulting from the exposure. The analysis subsystem can include an inductively coupled plasma spectrometer or an atomic absorption spectrometer. [0020] In general, in still another aspect, the invention features a system for screening compositions in a test environment. The system includes a reactor block including a plurality of test cells, each of the test cells being configured to receive a test fluid and a test sample, a plurality of shuttles configured to fit in the plurality of test cells, each of the plurality of shuttles being shaped to define, when positioned in one of the plurality of test cells, a flow region along a surface of a test sample positioned in one of the plurality of test cells, each of the plurality of shuttles including a magnet, and a magnetic coupling system for driving the shuttle in a reciprocating motion along a length of the test cell. [0021] Particular embodiments can include one or more of the following features. The test samples can include one or more metals. The test samples can include one or more coatings or films. The test samples can include one or more materials used in a refinery process. The test fluid can include a crude oil or crude oil fraction. The system can include a temperature control subsystem configured to heat at least a portion of the test cells. The shuttles define the flow region as an annular space around the corresponding test sample.

[0022] The includes an analysis subsystem for detecting an effect of exposure of the test samples to the test fluids. The analysis subsystem can be operable to analyze the test samples for changes resulting from the exposure. The analysis subsystem can include a profilometer. The analysis subsystem can be operable to analyze the test fluid for changes resulting from the exposure. The analysis subsystem can include an inductively coupled plasma spectrometer or an atomic absorption spectrometer. Two or more of the plurality of test cells can contain different test fluids and/or different test samples. The plurality of test cells can include a collection of test cells arranged in a reactor block. The plurality of test cells can include a plurality of collections of test cells, where each collection is arranged in one of a plurality of reactor blocks.

[0023] The invention can be implemented to realize one or more of the following advantages, alone or in the various possible combinations. The methods and systems of the present invention can be implemented using smaller active fluid volumes, and smaller test samples than conventional corrosion modeling techniques. Smaller fluid volumes and smaller test samples can lead to shorter residence times for test fluids at elevated test temperatures, thereby reducing the chances of fluid degradation occurring during testing. The methods and systems of the present invention can be implemented to provide for parallel testing of multiple samples and/or multiple fluids in short times and a relatively small-footprint device. The methods and systems of the present invention are amenable to automation, thereby facilitating development of high-throughput corrosion testing workflows. In some embodiments, the methods and systems of the present invention use pressure to control wall shear stress experienced at the surface of a sample under test, which may more accurately correlate to real-world corrosion effects than velocity control used in other techniques. By carefully selecting pressure and/or flow path shape, it may be possible to accommodate a wide variety of viscosities and flow regimes, such as turbulence and cavitation. Li some embodiments, multiple material samples can be incorporated in a single fluid flow path.

[0024] Parallel profilometry screening according to some embodiments of the invention can be used to assess the corrosion potential of many different test samples, potentially representing many different compositions, in a very short time. Profilometry screening can rapidly provide detailed information about the topography of corrosion effects in two or three dimensions, without requiring sectioning or elaborate preparation of samples for analysis. Only a small amount of each sample, and a small volume of the test fluid, may be needed to get useful corrosion data. Because the substrate and test samples can be physically very compact, and because little sample preparation is required, profilometry screening is amenable to incorporation in a high-throughput device. [0025] The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.

DESCRIPTION OF DRAWINGS

[0026] FIG. 1 is a flow diagram illustrating a general method for performing environmental testing.

[0027] FIG. 2 is a schematic diagram of one embodiment of a flow channel system for screening compositions in a test environment according to one aspect of the invention.

[0028] FIGS. 3 A to 3 C are schematic diagrams illustrating embodiments of the system shown in FIG. 2 in more detail.

[0029] FIG. 4 is a schematic diagram illustrating the analysis of corrosion results using profilometry. [0030] FIGS. 5A to 5C are schematic diagrams illustrating an embodiment of an array-based immersion system for screening compositions in a test environment according to one aspect of the invention.

[0031] FIGS. 6A and 6B are schematic diagrams illustrating an embodiment of a reciprocating shuttle-based system for screening compositions in a test environment according to one aspect of the invention.

[0032] FIG. 7 is a schematic diagram illustrating one embodiment of a parallel screening system incorporating a plurality of the test cells of FIG. 6 A.

[0033] FIGS. 8 A and 8B are schematic diagram illustrating a further embodiment of a parallel screening system incorporating a plurality of test cells of FIG. 6A.

[0034] FIG. 9 is a plot of observed corrosion rate of carbon steel samples in vacuum gas oil fractions of differing total acid number obtained using a multi-well reciprocating shuttle cell screening system as shown in FIG. 7.

[0035] Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

[0036] The invention provides methods and apparatus for use in testing the effects of exposing a plurality of samples in parallel to a test environment. In general, the methods and apparatus may be used in studying transformations that may result from the exposure of solid materials to a test environment. The test samples can include a variety of different materials, including, for example, metals, ceramics, plastics, biomaterials, gels, coatings and films, and can be provided as elemental solids, mixtures, or alloys, optionally including one or more impurities or dopants, and may be treated with one or more surface treatments, which can include treatment with other materials, such as coatings or films, or chemical or physical treatments such as polishing, etching, etc. The test environment typically features one or more test fluids, which can be in liquid or gaseous form. The test fluid can be a single-component fluid, or can be a mixture (including a liquid-gas mixture) of multiple components, hi some embodiments, the test fluid includes a base fluid (which may itself be a mixture of components) and one or more additives - for example, a lubricant or crude oil containing one or more anti- corrosion or anti-wear additives, hi such embodiments, the additives may include one or more additives that are specifically added to the test fluid to affect a process that is under study in the testing. In some embodiments the test environment can also include one or more solid materials. In typical embodiments, the testing involves contacting the test sample with the test environment, such as by flowing a test fluid over a surface of the test sample, or contacting a surface of the test sample with and moving the surface relative to a test solid, under controlled pressure, temperature, shear rate and/or wall shear stress conditions. The test samples and/or the test environment is/are then examined to detect any effects of the exposure ~ in particular, transformations of the test sample and/or a test fluid, such as corrosion of the test sample surface resulting from exposure to a test fluid flow.

[0037] hi some embodiments, the test samples and the test environment are selected to represent a real world process. For example, the test samples can include a plurality of structural materials, such as metal alloys that are used in a refinery, and the test environment can include one or more process fluids to which the structural materials are expected to be exposed, such as crude oils or crude oil fractions to which the metal alloys will be exposed in a refinery process. The testing can be implemented to examine the effects of varying environments on a given material or set of materials (e.g., some or all of the test samples can be identical, and the testing can involve exposing a plurality of identical samples to different test environments). Alternatively, the testing can be implemented to examine the performance of different materials in a given environment (e.g., some or all of the test samples can be different, and the testing can involve exposing different test samples to the same test environment). Thus, for example, the test samples can be selected to represent equipment used in a particular refinery (e.g., metal alloys such as 1045CS₅IOlOCS, 5Cr, 9CR, 410SS, 316SS, 317SS, 321SS, 825SS, and Al 06), and the testing can involve examining a variety of different crude oils or crude oil fractions to identify crude oils or fractions that can be advantageously processed in that refinery (or, conversely, to identify crude oils or fractions that should not be processed in the refinery). In another example, the test samples can include a plurality of new materials (e.g., coatings or surface-treated materials) and the testing can be performed to identify the best performing materials under specified conditions. [0038] A general method 100 for testing a plurality of test samples is illustrated in FIG. 1. A plurality of test samples and one or more test fluids are loaded into a test system that includes one or more test cells (step 110). The test samples can include a plurality of different materials, and/or some or all of the test samples can be identical. The test samples can include one or more reference samples that will be used as standards to determine the effect upon one or more other test samples of exposure to the test environment. Each test cell can be loaded with one or more of the test samples. [0039] The test samples are exposed to the test environment (step 120). In general, the exposing involves contacting the test samples with a test fluid or fluids in the test environment, such that the test fluid(s) and test samples interact. The interaction typically occurs at a solid-liquid interface, and involves chemical action, whereby a test fluid contains a species that may interact with a surface of a test sample, causing a chemical transformation to the surface (although in some embodiments, the transformation may extend below the test sample surface), or flow action, whereby hydrodynamic or mechanical forces exerted on the surface of a test sample by a test fluid flow may cause removal of material from the test sample surface. In particular embodiments, the test samples and test fluids can interact through either or both of chemical action and/or flow action, hi some embodiments, each test sample may be exposed to identical conditions. Alternatively, some or all of the test samples may be exposed to different conditions, such as different pressures, different temperatures, different shear rates or different wall shear stress. The conditions experienced by individual test samples may be constant or may vary during the testing. [0040] In some embodiments, the test samples are exposed to one or more test fluids (or test solids) under conditions in which the test samples subjected to motion relative to the test fluids (and/or test solids) - for example, conditions under which the test samples are exposed to a flow of the test fluid(s). In some embodiments, this can involve exposure of the test samples to test fluid(s) under controlled flow conditions, such as controlled pressure, temperature, shear rate, wall shear stress, or turbulence conditions, hi particular embodiments, this may involve controlling conditions at which phase transitions can/will occur in the test fluid - for example, controlling conditions to avoid (or provide) locals drops in pressure, which can lead to vaporization and/or cavitation or to avoid (or provide) local increases in pressure, which can lead to the formation of crystals in the test fluid or the precipitation of material that is suspended in the test fluid. [0041] In some embodiments, flow conditions may be controlled to simulate conditions found or expected in a particular real-world system. Thus, for example, the test samples may be exposed to simple test fluid flows that simulate systems in which the flow field at the test sample surface is well-defined (e.g., flow systems in which shear is defined at every point in the fluid flow) or undefined (e.g., turbulence arising in a high pressure pump). Alternatively, the test samples can be exposed to complex flows, such as flows that represent flows that may be encountered in fluid- filled mechanical assemblies, such as power transmission devices (e.g., gear boxes), petrochemical processing and refining equipment, or turbo machinery (e.g., jet engines). In some cases, the flow field experienced by the test samples in these latter embodiments may be undefined.

[0042] Finally, the test samples and/or the test environment is/are analyzed (step 130). This can involve analyzing each of the test samples (or surfaces thereof) to detect chemical or physical changes resulting from the exposure to the test environment. Such changes can include, for example, the formation of deposits at the test sample surface (e.g., scale or varnish formation, plating), the removal of material from the test sample surface (e.g., corrosion, wear), or chemical or morphological changes to the test sample or test sample surface (e.g., annealing, migration of ions, changes in crystallinity), and can be detected using conventional techniques such as by measuring changes in resistance, weight loss, x-ray analysis, or surface analysis techniques measuring, e.g., changes in surface texture or color. Alternatively, or in addition, the analysis can involve analyzing the test fluid(s) to detect chemical or physical changes to the fluid(s). These changes can include, for example, the addition of material to the test fluid (e.g., the addition of test sample material or degradation products thereof to the test fluid, resulting from corrosion or flaking), the depletion of an additive to the test fluid (e.g., the disappearance of anti-wear additives), or chemical changes in the composition of the test fluid itself, and can be detected using conventional techniques such as using acoustic measurements, chromatography or elemental analysis techniques. [0043] A test system 200 suitable for implementing method 100 is generally illustrated in FIG. 2. In system 200, a test sample 210 is supported on a sample holder 215, such that sample 210 is exposed to a flow path defined by flow channel 220 located in housing 225. Flow channel 220 is in fluidic communication with fluid reservoirs 230 and 235. Reservoirs 230, 235 are in communication with pumps 240 and 245, respectively, which cooperate to generate a reciprocating flow of a test fluid 250 from reservoir 230, through flow channel 220 and across the exposed surface of test sample 210 to reservoir 235, and back again. Housing 225 includes and/or is coupled to temperature control hardware (not shown), and is therefore able to provide heating or cooling in temperature controlled region 255. Optionally, cooling (or heating) can be provided in the vicinity of reservoirs 230, 235 to cool test fluid 250 after heating in region 255 (or vice versa), thereby limiting or preventing thermal degradation (e.g., cracking) of test fluid 250 that might result from long residence times at elevated test temperatures. Housing 225 and/or sample holder 215 can be equipped with pressure seals (e.g., elastomeric or graphite gaskets, not shown), which make it possible to maintain elevated (or reduced) pressure within flow channel 220. Test sample 210 can be provided in any desired shape or structure that provides a sufficient surface for testing. Test sample 210 can be grounded to avoid corrosion due to differences in potential between the test sample and other materials that make up sample holder 215, flow channel 220 or housing 225.

[0044] In operation, the test sample 210 is mounted on sample holder 215, which is inserted into housing 225 such that test sample 210 is positioned within flow channel 220. Test fluid 250 is loaded into the system, and temperature control region 255 is heated to a desired test temperature. Pumps 240, 245 are activated, and fluid 250 is pumped back and forth between reservoirs 230 and 235 through flow channel 220 and across the surface of test sample 210. After a desired number of cycles (or a desired amount of time), pumps 240 and 245 are deactivated, and sample holder 215 is removed from housing 225. Test sample 210 and/or test fluid 250 is then analyzed to detect corrosion resulting from the flow of test fluid 250 across the test sample surface. In many embodiments, system 200 can be operated in combination with robotic sample handlers, automated liquid dispensers, automated analytical instruments, and control software to provide an automated, high-throughput workflow.

[0045] System 200 is operated under conditions of controlled pressure, temperature, shear rate and/or wall shear stress. It is known that corrosion rate has a better correlation to wall shear stress than other fluid flow properties. Accordingly, in a preferred embodiment system 200 is operated using controlled pressure driven flow rather than controlled displacement, such that the wall shear stress experienced by test sample 210 may be controlled independently of viscosity or temperature, according to the formula:

2-L In particular embodiments, controlled pressure driven flow is provided by using a constant force to a pair of syringe pumps {e.g., where syringe pump 240 is actively driven and syringe pump 245 responds passively) or a pair of pressure-actuated diaphragm pumps, where the two pumps control the upstream and downstream pressure and the flow results from the pressure difference through flow channel 220. It is expected that most of the controlled pressure drop in this configuration occurs through the flow restriction in the vicinity of the test sample, generating uniform wall shear stress (where wall stress = pressure drop / wall area). Under these conditions, the flow rate/velocity will vary with viscosity but the wall shear stress will remain constant. [0046] As noted above, system 200 can be operated such that test sample 210 and test fluid 250 are exposed to elevated temperature or pressure. In some applications, temperature controlled region 255 can be heated to a temperature at which test fluid 250 or one or more components thereof undergoes a phase transition, such as a flash vaporization, in flow channel 220 (in which case, pressure changes resulting from the phase change can be controlled by applying appropriate back-pressure to pumps 240 and/or 245. The temperature, pressure, and wall shear conditions can be selected to represent actual or expected conditions in a real-world process. Alternatively, testing can be conducted under more drastic conditions with temperature, pressure, shear rate and wall shear stress elevated above actual or expected levels to provide for accelerated corrosion and/or wear of test sample 210 (thereby decreasing the amount of time required to observe the effects of corrosion and/or wear).

[0047] A more specific embodiment of system 200 is illustrated in FIG. 3 A. There, a system 300 features a heated reactor block 305, which includes a flow channel 310. Reactor block 305 can be fabricated from a variety of conventional materials, including, for example, metal alloys, ceramics and the like. Preferably, surfaces exposed to the test environment, such as surfaces that form flow channel 310 are formed from (or coated with) materials that are inert to the test environment under study. A sample chamber 315 in block 305 is configured to receive test sample plate 320, positioned directly above and in contact with a channel plate 325, described in more detail in the context of FIG. 3B, below. Chamber 315 is sealed with access plug 330. Optionally, test sample plate 320 may be mounted on a bottom surface of access plug 330, although in typical embodiments, sample plate 325 is simply placed into chamber 315 on top of channel plate 325. Inlets/outlets 335 provide fluidic communication between flow channel 310 and fluid reservoirs and pumps (not shown) as discussed above. Block 305 also features fluid inlets/outlets 340, which can be used to load test fluid at the start of a test procedure, and to remove test fluid for analysis at the end of the procedure (or, optionally, while the test procedure is underway). Temperature monitoring and control is provided by means of thermocouple connection 345.

[0048] As noted above, test sample plate 320 is positioned in reactor block 305 in communication with channel plate 325. As shown in FIG. 3B, test sample plate 320 can be provided as a single, monolithic plate of a desired test material, with a smooth bottom surface (optionally, coated or surface-treated as discussed above). Channel plate 325 is fabricated (by etching, micromachining or other conventional processes) to have a flow channel 350 formed in its upper surface, such that a portion of the bottom surface of test sample plate 320 forms an upper edge of flow channel 350 when test sample plate 320 and channel plate 325 are positioned in sample chamber 315 of reactor block 305. As shown in FIG. 3B, channel plate 325 also features inlet/outlet ports 355, which provide for fluid communication between flow channel 350 of channel plate 325 and flow channel 310 in reactor block 305, thereby exposing a portion of the bottom surface of test sample plate 320 to a test fluid flowing in flow channel 310 (and 350). Optionally, system 300 can include sealing layers (e.g., elastomeric or graphite gaskets) between test sample plate 320 and channel plate 325 and/or between channel plate 325 and reactor block 305 to provide for a fluid-tight seal.

[0049] System 300 can be implemented to provide for high-throughput testing. In some embodiments, high-throughput testing can be achieved by providing for parallel testing of a plurality of test samples. One such parallel testing embodiment, featuring a single reactor block configured to support parallel (simultaneous) testing of multiple test samples, is illustrated in FIG. 3C. As shown there, a sample block 360 includes a substrate supporting ^plurality of test samples 370 exposed at a substrate surface 365. In particular embodiments, the test samples can be deposited on the surface of sample block 360 (e.g., using chemical or physical vapor deposition, or other surface deposition or coating techniques), or embedded into cavities formed in sample block 360 - for example, by press fitting, soldering, brazing, an adhesive, or the like. A channel plate 375 includes a plurality of channels 380, which each extend through the thickness of and define a flow path along at least a portion of channel plate 375, such that when channel plate 375 is positioned in contact with the surface 365 of sample block 360, each channel 380 is adjacent to one or more of the test samples 370 supported by sample block 360. A distribution plate 385 includes distribution channels 390, which provide for distribution of the test fluid to each channel 380 in channel plate 375. Distribution channels 390 are, in turn, in fluid communication with inlet/outlet ports 397 in base plate 395. Test samples 320, 370 can be fabricated in any desired shape or structure, so long as they provide a surface for testing. Optionally, test samples 370 can be connected to a common ground to avoid corrosion due to differences in potential between test sample materials.

[0050] Optionally, as discussed above in the context of test sample plate 320 and channel plate 325, one or more sealing layers (e.g., elastomeric or graphite gaskets) can be provided between sample block 360, channel plate 380, distribution plate 390, base plate 395 and/or reactor block 305 to provide for a fluid-tight seal. It should be noted that although a separate channel plate 375, distribution plate 385 and base plate 395 are shown in FIG. 3C, these plates can be combined in a single channel plate (e.g., plate 325, FIG. 3B), which, for example, may be fabricated from a single layer of material, or as a bonded laminate of layers 380, 390, 385, if desired.

[0051] In operation, sample block 360, channel plate 375, distribution plate 385 and base plate 395 are positioned in sample chamber 315 of reactor block 305, such that inlet/outlet ports 397 are in fluid communication with flow channel 310. A test fluid flowing in flow channel 310 passes through an inlet port 397 in base plate 395, and split into separate flows for each of the channels 380 in channel plate 375 by means of a first distribution channel 390 in distribution plate 385. The separate test fluid flows through channels 380, past test samples 370, and enters the opposite distribution channel 390 in distribution plate 385. In distribution channel 390, the separate flows of test fluid are combined, and the combined test fluid re-enters flow channel 310 through the outlet port 397 in base plate 395.

[0052] In some embodiments, the system can be configured such that the test samples 370 associated with each channel 380 in channel plate 375 are exposed to a different test environment by providing separate heat exchangers, flow channels and/or pumps for each channel. This arrangement does, however, increase the mechanical complexity of system 300 (although it should be noted that some variation in test environment conditions - specifically, pressure, shear rate and/or wall shear stress - can be provided by including channels 380 having different geometries in a single channel plate 375, such that the test samples 370 associated with one channel 380 will experience a different test environment than those associated with another channel), and it may be preferable to conduct parallel testing using a plurality of reactor blocks, each of which can be configured to house one or many test samples (e.g., the embodiments of FIG. 3B or FIG. 3C) and be operated to provide a different test environment for its associated test samples. Thus, a multi-reactor block system can be provided, with each reactor block housing a multi-sample block 360 and associated plates 375, 385, 395 (or, alternatively, a single sample plate 320/channel plate 325 combination as in FIG. 3B), and with testing in each block performed under a single set of conditions (i.e., a single test fluid at a single pressure, temperature, shear rate, etc.).

[0053] The operating conditions for systems 200, 300 are not narrowly critical and will be determined by the particular application. In typical embodiments, the systems are operated in an inert atmosphere with total liquid volumes (of test fluid) in the range from about 0.1 to about 1.0 ml, at temperatures in the range from about 15O⁰C to about 55O⁰C, pressures in the range from about 1 to about 10 bar, and wall shear stress in the range from about 0 to about 1000 Pascal to provide a measurable corrosion range from about .1 to about 10 mmpy.

[0054] Test samples and/or test fluids can be analyzed using a variety of different techniques, including electrical or electrochemical measurement in-situ (e.g., EIS, resistance probes, etc.), analysis of the test fluid for corrosion products (e.g., chromatography (GC, HPLC), inductively coupled plasma - mass spectrometry (ICP- MS), inductively coupled plasma - optical emission spectrometry (ICP-OES), atomic absorption spectroscopy (flame AA, graphite furnace AA, hydride-generation AA), or direct measurement of material loss (e.g., profilometry).

[0055] hi particular embodiments, corrosion product analysis may be preferred. Corrosion product analysis techniques can be robust, offer rapid sample analysis, low detection limits and the possibility of performing autosampling off-line. Profilometry techniques can be used to measure changes in the topography (e.g., height, roughness) of the test sample surface. Suitable techniques include contact profilometry, in which a stylus (e.g., a diamond tipped stylus) is dragged across the test sample surface, and a piezoelectric sensor registers displacement of the stylus in z dimension, or optical profilometry, in which the height (again, in the z dimension) at various points across the test sample surface is measured by interferometry. Both contact and optical techniques can be used to provide measurements in two or three dimensions. Optical techniques can be particularly advantageous, rapidly providing three-dimensional images covering the entire field of view (e.g., 600x400 pixels) with resolution to less than 10 nm on rough samples. Alternatively, profilometry can include microscopy techniques such as scanning electron microscopy and atomic force microscopy. All of these techniques can be readily automated, thus supporting high-throughput workflows. One embodiment of profilometry analysis will now be described in reference to FIG. 4. [0056] A plurality of test samples 410 are embedded in a substrate 400 (e.g., sample block 360, FIG. 3C), and planarized to define test sample surfaces 420. The substrate is then exposed to a corrosive environment (e.g., in system 300 as discussed above. Following exposure, the substrate topography is examined using a profilometer, and a measure of corrosion is obtained by measuring the relative height difference Δ between the surface 420 of each test sample and a reference surface, which can be the substrate surface 430, or the surface of a reference sample (e.g., a material, such as tantalum, that is not reactive or only weakly reactive in the test environment) embedded in substrate 400. The surface roughness of each test sample is also measured and compared to that of the reference surface. The testing can include reciprocating movement of the test fluid back and forth across the test sample surface, as discussed above. Alternatively, the testing can involve immersion of the substrate and test samples in a static or stirred volume of the test fluid, movement of the test fluid across the substrate and sample surfaces by bulk flow, or orbital movement of the substrate and sample surfaces relative to the test fluid to create shear stress at the solid-fluid interface. [0057] In a more specific embodiment, a grid of through-holes is machined into a substrate of 316 stainless steel. Pins of various alloys are press fit into the holes, and the surface is planarized so that the height difference between the alloys and the surrounding substrate surface is less than 1 micron (as measured by surface contact profilometry). The substrate is attached to a magnetically driven holder. The substrate and holder are immersed in a crude oil with an unknown corrosion ability having a total acid number (TAN) between 0.7 and 6. The apparatus is heated and magnetically driven to create thermal and shear conditions that mimic those found in crude flow in refinery piping - for example, 4 TAN at 23O⁰C for 24 hours at a series of increasing shear rates. After this treatment, the test sample (pin) surfaces are examined using surface contact profilometry, and are observed to be recessed from the surface of the stainless steel substrate by a few hundred nanometers. The test sample surfaces are also observed to have increased surface roughness or pitting.

[0058] An alternative test system 500 suitable for implementing method 100 is generally illustrated in FIGS. 5A-5C. A multi-well plate 510 is mounted on the bottom surface of a pressure vessel 520. Plate 510 includes a plurality of test wells 530 for receiving one or more test fluids 580. A sample holder 540 is also positioned within pressure vessel 520. As shown in FIG. 5B, a plurality of test samples 550 are mounted in sample holder 550. The test samples are provided as pins or rods that protrude above a surface of sample holder 540, and are arranged in a pattern that is complementary to a pattern of the test wells in well plate 510. Sample holder 540 is positioned within pressure vessel 520 by inverting sample holder 540 and lowering sample holder 540 onto plate 510 such that each of the test sample pins 550 is lowered into a corresponding test well 530.

[0059] A top surface 560 of each test sample 550 is exposed for testing, as will be described in more detail below. All other surfaces of test samples 550 are treated to render them inert to the test environment - for example, by coating these surfaces with an inert coating 570 (e.g., a ceramic). All exposed surfaces of sample holder 540 and test wells 530 are fabricated from or coated with such an inert material as well. [0060] In operation, pressure vessel 520 is opened, and multi-well plate 510 is positioned within. One or more test fluids 580 are dispensed into test wells 530. Depending on the particular application, the same test fluid 580 can be dispensed to some or all of the test wells 530 in plate 510. Alternatively, or in addition, different test fluids 580 can be dispensed to some or all of the test wells 530. Sample holder 540 is lowered onto plate 510 (as shown in FIG. 5C) such that each test sample 550 is positioned within a corresponding test well 530 with its test surface 560 immersed in the corresponding test fluid 580 at a predetermined distance 590 from the bottom surface of test well 530. Pressure vessel 510 is sealed and, optionally, heated to a desired temperature. A magnetic coupling subsystem (not shown) generates a rotating magnetic field within pressure vessel 510, which drives a cyclical motion of sample holder 540 relative to plate 510. This motion causes each test sample 550 to move within its corresponding test well, which displaces test fluid 580 and forces the fluid to flow across test surface 560, thereby creating wall shear at the test surface. In particular embodiments, sample holder 540 can be moved in a linear, reciprocating motion relative to plate 510. Alternatively, sample holder 540 can be moved in another pattern, such as a circle, an ellipse, or a more complicated pattern. Preferably, system 500 is configured such that a predetermined gap 590 is maintained between each test surface 560 and the bottom surface of the corresponding test well 530 throughout the motion of sample holder 540. By controlling the size of gap 590 and the speed of motion, controlled wall- shear stress conditions can be created.

[0061 ] After the test samples have been exposed to the test environment for a desired amount of time, pressure vessel 520 is unsealed and sample holder 540 is removed. Test samples 550 and/or test fluids 580 are then analyzed to detect corrosion of the test samples. Test samples 550 can be examined for visual evidence of corrosion (e.g., color change), or using profilometry techniques as discussed above. Test fluids 580 can be analyzed using one or more of the corrosion product screens (e.g., ICP-MS, ICP-OES, GFAA, Flame AA, Hydride-generation AA) discussed above.

[0062] Sample holder 540 can be configured to hold any number of test samples 550, such as at least 8, at least 64, at least 128, at least 196 or 256 or more test samples (and plate 510 configured to include a corresponding number of test wells 530). In particular applications, some or all of the test samples 550 can be fabricated from identical materials; alternatively, or in addition, some or all of the test samples 550 mounted on sample holder 540 can be different (either in composition, coating, surface treatment, etc.). One or more of the test samples mounted in sample holder 540 can be a reference sample as discussed above. Test samples 550 can be fabricated in with any desired shape or structure, so long as they provide a test surface 560 that can be positioned at the specified distance 590 from the bottom surface of test wells 530. Optionally, test samples 550 can be connected to a common ground to avoid corrosion due to differences in potential between test sample materials. Two or more systems 500 can be operated together to provide high-throughput testing of test samples in different test environments. 111 some embodiments, system 500 can include robotic sample handling and liquid handling devices and automated analytical instruments to provide for an automated high- throughput workflow operating under computer control.

[0063] Although system 500 has been described in the context of corrosion testing with a precisely-defined gap maintained between test surfaces 560 and the bottom surface of test wells 530, the system is also suited for use in friction/wear testing. For such applications, sample holder 540 is positioned such that test surfaces 560 are in direct contact with the bottom surface of test wells 530. Movement of sample holder 540 relative to plate 510 results in friction between test surfaces 540 and test wells 540. Wear resulting from this friction can be observed using the profilometry and/or fluid analysis techniques discussed above.

[0064] The operating conditions for system 500 are not narrowly critical. In particular embodiments, system 500 can be operated at temperatures ranging from about 150⁰C to about 55O⁰C, at pressures ranging from about 1 to about 10 bar, and at average shear rates from about 0 to about 10,000 /s, with sample volumes in the range from about 150 to about 400 μl.

[0065] Still another alternative test system 600 suitable for implementing method 100 is generally illustrated in FIGS. 6A-6B. A temperature-controlled housing 610 includes a central cavity sized and shaped to hold a test cell 620, which includes a test chamber 630. An elongated test sample 640 {e.g., a 1/16" diameter by 1" long pin) can be positioned in a notch formed in test cell 620 at the bottom of test chamber 630. A shuttle 650 fits into an open end of test chamber 630, forming a flow path along at least a portion of a surface of test sample 640, as will be described in more detail below. A cap 660 covers the open end of test chamber 630, forming a pressure-tight seal when a top portion of housing 610 is coupled to a bottom portion of housing 610. [0066] One embodiment of shuttle 650 is illustrated in more detail in FIG. 6B. In this embodiment, shuttle 650 is formed as a cylindrical solid with a hollow central shaft 670 that is configured to receive a cylindrical test sample 640. Shaft 670 has a larger diameter than test sample 640, such that an annular space is formed around test sample 640 when test sample 640 and shuttle 650 are positioned within test chamber 630. Shuttle 650 includes a magnetic material 680 - in the illustrated embodiment, four magnetic cylinders 680 in sealed channels 690 positioned at regular intervals along the circumference of shuttle 650. Housing 610, test cell 620, shuttle 650 and cap 660 can be fabricated from a variety of different materials. In some embodiments, housing 610 is fabricated from stainless steel, while test cell 620 and shuttle 650 are fabricated from ceramic materials.

[0067] hi operation, system 600 is prepared for corrosion testing by first opening housing 620. Test cell 620 can be pre-positioned in housing 610, or a test cell 620 can be positioned in a cavity in housing 610 at this time. A test sample 640 is positioned in the notch at the bottom of test chamber 630, and a test fluid is dispensed into test chamber 630. Shuttle 650 is then positioned within test chamber 630, such that test sample 640 extends within shaft 670 of shuttle 650. Cap 660 is placed in position over the open end of test chamber 630, and housing 610 is sealed. Housing 610 is heated to a desired test temperature, and a magnetic coupling subsystem (not shown) generates a magnetic field that drives shuttle 650 from one end of test chamber 630 to the other. As it moves, shuttle 650 displaces the test fluid, which is forced through the annular space and along the exposed surface of test sample 640, thereby creating a wall shear at that surface. The magnetic coupling is reversed, and the shuttle is driven in the opposite direction, back the other end of test chamber 630, again displacing test fluid as it moves. This operation is repeated for the desired duration of the testing, resulting in a reciprocating motion by shuttle 650 within test chamber 630. The shear experienced at the surface of test sample 640 stress is a function of the size of the gap between shuttle 650 and test sample 650 and, to a lesser extent, the frequency of the shuttle's motion (such that the average stress can be controlled by varying the shuttle frequency). After the passage of a desired amount of time, the magnetic coupling is deactivated, and housing 610 is allowed to cool and is unsealed. Test sample 640 and/or the test fluid can be removed from test chamber 630 and analyzed to detect corrosion — for example, by measuring trace metals in the test fluid, by performing profilometry or elemental analysis on the surface of test sample 640, or by measuring mass change of the test sample - using the techniques discussed above.

[0068] A multi-cell embodiment of system 600 is illustrated in FIG. 7. A system 700 features twelve test cells 710 arranged in temperature-controlled housing 720 in a ring around a central cavity. Test cells 710 and housing 720 are analogous to test cells 620 and housing 610 described in the context of FIGS. 6A and 6B, above. Magnetic coupling assembly 730 includes a disk that houses magnetic material arranged around the circumference of a ring that corresponds to the ring of housing 720. [0069] In operation, test cells 710 are loaded as described above for test cells 620. In particular embodiments, each test cell 710 may be loaded with a different combination of test sample and test fluid to provide for simultaneous testing of twelve different sample/fluid pairs. Alternatively, two or more test cells 710 can be loaded with the same test sample and test fluid, in order to provide replicates as a check on the validity of experimental results. When all test cells have been loaded, housing 720 is sealed and heated to a desired temperature, thus providing a uniform thermal environment for all twelve test cells 710. Magnetic coupling assembly 730 is rotated below housing 720, thus creating a rotating magnetic field that drives the magnetic shuttles within each test cell 710 in a reciprocating motion as described in the context of FIGS. 6A-6B above. After a desired period of time, the housing is cooled and opened, and the test samples and/or test fluids are removed for analysis as described above.

[0070] Still higher throughput can be obtained by combining a plurality of multi-cell units in a single system 800, as shown in FIG. 8A. As shown, system 800 includes six twelve-cell modules 810 mounted on a base 820. As shown in FIG. 8B, each module 810 includes a twelve-cell unit 700 as described above, positioned within a heater 830, which provides a uniform thermal environment for all of the test cells in the module. An insulation shroud 840 isolates each module from the other modules in the system. System 800 can be operated to provide for a wide variety of test environments in a single multi-channel experiment. For example, by providing a different temperature in each module 810, up to 72 different test sample/test fluid pairs at eight different temperatures, hi addition, each module (or, in some embodiments, each test cell) can be subjected to experimental conditions for a different experiment time. Likewise, by using different shuttles (e.g., shuttles providing for flow paths of different sizes around the test sample) in some or all of the test cells, and/or by varying the frequency of shuttle motion, different shear rates can be provided in some or all of the test cells. Optionally, testing can be performed under an inert atmosphere. Optionally, test samples can be grounded to avoid corrosion due to differences in potential. In particular embodiments, multi-cell reactors (e.g., 700, FIGS. 7, 8B) can be implemented with more or fewer than twelve test cells. Likewise, multi-module systems (e.g., 800) can be implemented with more or fewer than six modules. As noted for the other systems discussed above, any of systems 600, 700 and 800 can be implemented in combination with automated fluid and/or sample handling robotics, as well as automated analytical instruments, to provide for an automated, high-throughput corrosion screening workflow. [0071] Typical embodiments of systems 600, 700 and/or 800 can be operated at temperatures in the range from about O⁰C to about 35O⁰C, and at pressures in the range from about 1 to about 50 bar. Tests are typically performed using from about 100 to about 750 μl of test fluid (with fluids having viscosities in the range from about 1 to about 50 cSt), at wall shear stresses in the range from 0 to about 500 Pa. [0072] In a particular embodiment, a process for evaluating the corrosive effect of a refinery feedstock on the metallurgy of one or more refinery processes can be implemented in a system comprising a parallel 96 channel reciprocating shuttle corrosion reactor. The corrosion reactor includes 96 test cells arranged in eight 12-cell metal blocks. Each block includes a two-part housing in the shape of a disc, including a lower portion with indentions for each of the test cells, and provides a uniform thermal environment for all twelve cells in the unit. The test cells are set in the indentions and an upper portion of the housing is pressed against the lower portion to form a seal around each of the test-cell indentions.

[0073] Each test cell is fabricated from ceramic or ceramic coated stainless steel. The test cell is in the shape of a hollow cylinder, with an indentation for receiving a 1" long by 1/16" diameter metal corrosion coupon along the central axis of the test cell. An annular magnetic shuttle fits within the test cell cylinder and around the metal coupon, such that a defined space exists between the coupon and shuttle. Magnetic coupling is produced by a rotating quadrupole magnetic assembly located directly below the housing.

[0074] In operation, a robotic liquid sample preparation and loading system is used to dispense a known amount (approximately 450 mg) of a test liquid representing, e.g., one of a plurality of different crude distillate fractions, into each cell in the reactor. After loading, each test cell is placed into an indentation in one of the 12-cell reactor block. A metal corrosion coupon and magnetic shuttle are added to each cell. Up to eight such blocks are loaded (such that up to 96 different liquid/metal pairs can be tested) and the blocks are sealed under inert atmosphere. [0075] Each block is heated to a predetermined temperature and the magnets associated with each block are rotated to drive the shuttle in each cell. The magnetic force causes each shuttle to be alternately repelled or attracted generating a vertical reciprocating motion within each test cell. As the magnetic shuttle is driven from one end of the test cell to the other, it displaces the liquid contained in the cell, forcing the liquid through the narrow annular space between shuttle and pin and generating an alternating high velocity flow. This motion creates a controlled cyclical wall shear stress at the surface of the corrosion coupon simulating shear stress experienced in pipes or other commercial fluid devices. This reciprocating shuttle motion is continued at the set temperature for between 1 and 48 hours.

[0076] Each reactor block is then opened, and the robotic liquid sample preparation and loading system is used to transfer a sample of each test liquid (approximately 150 mg) to a glass vial and dilute the liquid by a factor of 20 (w/w) with PremiSolv ICP solvent (Conostan/ConocoPhillips Co.). The diluted samples are then heated and mixed. The concentration of one or more elements (e.g., iron) in the diluted test liquid is then determined by inductively coupled plasma - optical emission spectrometry (ICP-OES, IRIS Intrepid II XSP with Cetac auto-sampler, Thermo Electron Corp.). A corrosion index (in mm per year) is calculated for each liquid/metal pair from the measured concentration of corrosion products, which is expected to correlate with long-term corrosion rates for the metal. Results obtained over a 12 hour period at 27O⁰C for a carbon steel test sample in vacuum gas oil at four different Total Acid Number values are shown in FIG. 9.

[0077] A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Thus, for example, although the invention has been described in the context of particular compositions and applications, the compositions and applications described herein are merely examples of uses for the apparatus and methods of the invention, which may be used in other applications without departing from the scope of the invention. Accordingly, other embodiments are within the scope of the following claims.

Claims

WHAT IS CLAIMED IS:

1. A method for screening compositions in a test environment, the method comprising: positioning one or more test samples in a flow channel; exposing the test samples to a reciprocating flow of a test fluid in the flow channel under controlled wall-shear conditions; and detecting an effect of the exposing on the test samples.

2. The method of claim 1 , wherein: positioning the test samples includes positioning a plurality of different test samples in the flow channel.

3. The method of claim 2, wherein: the plurality of different test samples differ based on their constituent materials, coatings and/or surface treatments.

4. The method of any of claims 1 to 3, wherein: the test samples include one or more metals.

5. The method of any of claims 1 to 4, wherein: the test samples include one or more coatings or films.

6. The method of any of claims 1 to 5, wherein: the test samples include one or more materials used in a refinery process.

7. The method of any of claims 1 to 6, wherein: the test samples include one or more test samples having a test surface smaller than about 2 cm²; and exposing the test samples includes exposing the test surface of each of the one or more test samples to the reciprocating fluid flow.

8. The method of any of claims 1 to 7, wherein: the flow channel has a volume in the range of about 0.5 ml to about 10 ml.

9. The method of any of claims 1 to 8, wherein: exposing the test samples includes heating at least a portion of the flow channel.

10. The method of any of claims 1 to 9, wherein: exposing the test samples includes controlling wall-shear conditions by controlling a pressure within the flow channel.

11. The method of any of claims 1 to 10, wherein: exposing the test samples includes pumping the test fluid using a syringe pump or a diaphragm pump to provide the reciprocating fluid flow.

12. The method of any of claims 1 to 11 , wherein: the test fluid comprises a crude oil or crude oil fraction.

13. The method of any of claims 1 to 12, wherein: detecting an effect includes analyzing the test samples for changes resulting from the exposing.

14. The method of claim 13 , wherein: analyzing the test samples includes analyzing the test samples for changes in a surface property or weight of the test samples.

15. The method of any of claims 1 to 14, wherein: detecting an effect includes analyzing the test fluid for changes resulting from the exposing.

16. The method of claim 15 , wherein: analyzing the test fluid includes analyzing the test fluid for the presence of elements or ions or a change in pH.

17. The method of any of claims 1 to 16, wherein: positioning the test samples includes positioning one or more test samples in each of a plurality of flow channels; and exposing the test samples includes exposing the test samples in each the plurality of flow channels to a reciprocating flow of one or more test fluids under controlled pressure conditions.

18. The method of claim 17, wherein: positioning the test samples includes positioning a different test sample in each of the plurality of flow channels.

19. The method of either of claims 17 or 18, wherein: exposing the test samples includes exposing the test samples in each of the plurality of flow channels to a reciprocating flow of a different test fluid under controlled pressure conditions.

20. A method for screening compositions in a test environment, the method comprising: providing a sample array including a substrate and a plurality of test samples mounted in or on the substrate, each of the test samples having a test surface; providing a fluid array including a plurality of wells, each of the plurality of wells containing a test fluid; immersing the test samples in the fluid array wells to expose the test surfaces to the test fluids, the test samples and fluid array wells being positioned to define a spatial relationship between each test surface and a bottom surface of the corresponding well; moving the sample array relative to the fluid array while maintaining the spatial relationship between the test surfaces and bottom surfaces; and detecting an effect of the moving on the test samples or the test fluids.

21. The method of claim 20, wherein: the sample array includes a plurality of different test samples.

22. The method of either of claims 20 or 21 , wherein: the test samples include one or more metals.

23. The method of any of claims 20 to 22, wherein: the test samples include one or more coatings or films.

24. The method of any of claims 20 to 23 , wherein: the test samples include one or more materials used in a refinery process.

25. The method of any of claims 20 to 24, wherein: the fluid array includes a plurality of different test fluids.

26. The method of any of claims 20 to 25, wherein: the test fluids comprise one or more crude oils or crude oil fractions.

27. The method of any of claims 20 to 26, wherein: each of the test samples has one or more side surfaces, and each of the plurality of wells has an internal surface, the side surfaces and the internal surfaces being coated with one or more inert materials.

28. The method of any of claims 20 to 27, wherein: moving the sample array relative to the fluid array includes moving the sample array relative to the fluid array while maintaining a defined gap between the test surfaces and the bottom surfaces to create a controlled wall shear stress at the test surface; and detecting includes detecting an effect of the wall shear stress on the test samples.

29. The method of any of claims 20 to 27, wherein: moving the sample array relative to the fluid array includes moving the sample array relative to the fluid array while maintaining contact between the test surfaces and the bottom surfaces; and detecting includes detecting an effect of friction and/or wear on the test samples.

30. The method of any of claims 20 to 29, wherein: moving the sample array includes moving the sample array in an orbital pattern about an axis perpendicular to the bottom surfaces of the fluid array.

31. The method of any of claims 20 to 30, wherein: detecting an effect includes analyzing the test surfaces for changes resulting from the moving.

32. The method of any of claims 20 to 31 , wherein: detecting an effect includes analyzing the test fluids for changes resulting from the moving.

33. The method of claim 32, wherein: analyzing the test fluids includes analyzing the test fluids for the presence of elements or ions or a change in pH.

34. A method for screening compositions in a test environment, the method comprising: positioning a test sample in a each of a plurality of test cells; depositing a test fluid in each of the plurality of test cells; positioning a shuttle in each of the plurality of test cells, the shuttles defining a flow region along a surface of the test samples; moving each of the shuttles in the corresponding test cells to force a flow of the corresponding test fluid through the flow region; and detecting an effect of the test fluid flow on the test samples.

35. The method of claim 34, wherein: the test samples include one or more metals.

36. The method of either of claims 34 or 35, wherein: the test samples include one or more coatings or films.

37. The method of any of claims 34 to 36, wherein: the test samples include one or more materials used in a refinery process.

38. The method of any of claims 34 to 37, wherein: the test fluid includes a crude oil or crude oil fraction.

39. The method of any of claims 34 to 38, wherein: the test cells have a volume in the range of about 100 μl to about 5 ml.

40. The method of any of claims 34 to 39, further comprising: heating at least a portion of the test cells during the moving.

41. The method of any of claims 34 to 40, wherein: positioning the shuttles includes positioning the shuttles around the test samples to define the flow region as an annular space around each of the test samples.

42. The method of any of claims 34 to 41 , wherein: moving the shuttle includes moving the shuttles in a reciprocating motion from a first end of the test cells to ^}a second end of the test cells, and back.

43. The method of claim 42, wherein: moving the shuttles includes driving the test shuttles by magnetic coupling.

44. The method of any of claims 34 to 43 , wherein: detecting an effect includes analyzing the test samples for changes resulting from the test fluid flow.

45. The method of claim 44, wherein: analyzing the test samples includes analyzing the test samples for changes in a surface property or weight.

46. The method of any of claims 34 to 45, wherein: detecting an effect includes analyzing the test fluid for changes resulting from the test fluid flow.

47. The method of claim 46, wherein: analyzing the test fluid includes analyzing the test fluid for the presence of elements or ions or a change in pH.

48. The method of any of claims 34 to 47, wherein: depositing a test fluid includes depositing a different test fluid in two or more of the plurality of test cells.

49. The method of any of claims 34 to 48, wherein: positioning the test samples includes positioning a different test sample in two or more of the plurality of test cells.

50. The method of any of claims 34 to 49, wherein: the plurality of test cells includes a collection of test cells arranged in a reactor block.

51. The method of claim 50, wherein: the plurality of test cells includes a plurality of collections of test cells, each collection being arranged in one of a plurality of reactor blocks.

52. The method of any of claims 34 to 51 , further comprising: heating the test cells during the moving.

53. A method for screening compositions in a test environment, the method comprising: providing an array including a substrate and a plurality of test samples mounted in or on the substrate, each of the test samples having a test surface; exposing the test surface of each of the plurality of test samples to a test environment; examining the test surface of each of the plurality of test samples by using a profilometry technique to detect changes resulting from exposure to the test environment.

54. The method of claim 53, wherein: the array includes a plurality of test samples each comprising a different material.

55. The method of either of claims 53 or 54, wherein: the plurality of test samples includes a plurality of test samples comprising the same material.

56. The method of any of claims 53 to 55, wherein: the plurality of test samples includes one or more metals.

57. The method of any of claims 53 to 56, wherein: the plurality of test samples includes one or more test samples having test surfaces formed by one or more coatings or films.

58. The method of any of claims 53 to 57, wherein: the array includes one or more standard samples mounted in or on the substrate, each of the standard samples having a standard surface; and examining the test surfaces includes comparing the test surfaces to the standard surfaces.

59. The method of any of claims 53 to 58, wherein: the substrate has a surface; and examining the test surfaces includes comparing the test surfaces to the substrate surface.

60. The method of any of claims 53 to 59, wherein: exposing the test surface of each of the plurality of test samples to a test environment includes exposing two or more of the plurality of test surfaces to different test environments.

61. The method of any of claims 53 to 60, wherein: exposing the test surfaces includes exposing the test surfaces to a gas phase environment.

62. The method of any of claims 53 to 60, wherein: exposing the test surfaces includes exposing the test surfaces to a liquid phase environment.

63. The method of any of claims 53 to 62, wherein: exposing the test surfaces includes exposing the test surfaces to a static gaseous or liquid environment.

64. The method of any of claims 53 to 62, wherein: exposing the test surfaces includes stirring a liquid in contact with one or more of the test surfaces.

65. The method of any of claims 53 to 62, wherein: exposing the test surfaces includes transporting a gas or liquid across one or more of the test surfaces by bulk flow.

66. The method of any of claims 53 to 62, wherein: exposing the test surfaces includes transporting a gas or liquid across one or more of the test surfaces by reciprocating flow.

67. The method of any of claims 53 to 62, wherein: exposing the test surfaces includes immersing the test surfaces in the test environment and moving the test surfaces in an orbital motion relative to the test environment.

68. The method of any of claims 53 to 67, wherein: examining the test surfaces includes measuring a height difference for each of the test samples.

69. The method of any of claims 53 to 68, wherein: examining the test surfaces includes measuring a roughness for each of the test surfaces.

70. The method of any of claims 53 to 69, wherein: examining the test surfaces includes examining the test surfaces using a optical or contact profilometry.

71. The method of any of claims 53 to 69, wherein: examining the test surfaces includes examining the test surfaces using atomic force microscopy or scanning electron microscopy.

72. A system for screening compositions in a test environment, the system comprising: means for positioning one or more test samples in a flow channel; means for exposing the test samples to a reciprocating flow of a test fluid in the flow channel under controlled wall-shear conditions; and means for detecting an effect of the exposing on the test samples.

73. The system of claim 72, wherein: the means for positioning the test samples includes means for positioning a plurality of different test samples in the flow channel.

74. The system of claim 73, wherein: the plurality of different test samples differ based on their constituent materials, coatings and/or surface treatments.

75. The system of any of claims 72 to 74, wherein: the test samples include one or more metals.

76. The system of any of claims 72 to 75, wherein: the test samples include one or more coatings or films.

77. The system of any of claims 72 to 76, wherein: the test samples include one or more materials used in a refinery process.

78. The system of any of claims 72 to 77, wherein: the test samples include one or more test samples having a test surface smaller than about 2 cm²; and the means for exposing the test samples includes means for exposing the test surface of each of the one or more test samples to the reciprocating fluid flow.

79. The system of any of claims 72 to 78, wherein: the flow channel has a volume in the range of about 0.5 ml to about 10 ml.

80. The system of any of claims 72 to 79, wherein: the means for exposing the test samples includes means for heating at least a portion of the flow channel.

81. The system of any of claims 72 to 80, wherein: the means for exposing the test samples includes means for controlling wall-shear conditions by controlling a pressure within the flow channel.

82. The system of any of claims 72 to 81 , wherein: the means for exposing the test samples includes a syringe pump or a diaphragm pump for pumping the test fluid to provide the reciprocating fluid flow.

83. The system of any of claims 72 to 82, wherein: the test fluid comprises a crude oil or crude oil fraction.

84. The system of any of claims 72 to 83, wherein: the means for detecting an effect includes means for analyzing the test samples for changes resulting from the exposing.

85. The system of claim 84 , wherein: the means for analyzing the test samples includes means for analyzing the test samples for changes in a surface property or weight of the test samples.

• 86. The system of any of claims 72 to 85, wherein: the means for detecting an effect includes means for analyzing the test fluid for changes resulting from the exposing.

87. The system of claim 86, wherein: the means for analyzing the test fluid includes means for analyzing the test fluid for the presence of elements or ions or a change in pH.

88. The system of any of claims 72 to 87, wherein: the means for positioning the test samples includes means for positioning one or more test samples in each of a plurality of flow channels; and the means for exposing the test samples includes means for exposing the test samples in each the plurality of flow channels to a reciprocating flow of one or more test fluids under controlled pressure conditions.

89. The system of claim 88, wherein: the means for positioning the test samples includes means for positioning a different test sample in each of the plurality of flow channels.

90. The system of either of claims 88 or 89, wherein: the means for exposing the test samples includes means for exposing the test samples in each of the plurality of flow channels to a reciprocating flow of a different test fluid under controlled pressure conditions.

91. A system for screening compositions in a test environment, the system comprising: a sample array including a substrate and a plurality of test samples mounted in or on the substrate, each of the test samples having a test surface; a fluid array including a plurality of wells, each of the plurality of wells containing a test fluid; means for immersing the test samples in the fluid array wells to expose the test surfaces to the test fluids, the test samples and fluid array wells being positioned to define a spatial relationship between each test surface and a bottom surface of the corresponding well; means for moving the sample array relative to the fluid array while maintaining the spatial relationship between the test surfaces and bottom surfaces; and means for detecting an effect of the moving on the test samples or the test fluids.

92. The system of claim 91 , wherein: the sample array includes a plurality of different test samples.

93. The system of either of claims 91 or 92, wherein: the test samples include one or more metals.

94. The system of any of claims 91 to 93, wherein: the test samples include one or more coatings or films.

95. The system of any of claims 91 to 94, wherein: the test samples include one or more materials used in a refinery process.

96. The system of any of claims 91 to 95, wherein: the fluid array includes a plurality of different test fluids.

97. The system of any of claims 91 to 96, wherein: the test fluids comprise one or more crude oils or crude oil fractions.

98. The system of any of claims 91 to 97, wherein: each of the test samples has one or more side surfaces, and each of the plurality of wells has an internal surface, the side surfaces and the internal surfaces being coated with one or more inert materials.

99. The system of any of claims 91 to 98, wherein: the means for moving the sample array relative to the fluid array includes means for moving the sample array relative to the fluid array while maintaining a defined gap between the test surfaces and the bottom surfaces to create a controlled wall shear stress at the test surface; and the means for detecting includes means for detecting an effect of the wall shear stress on the test samples.

100. The system of any of claims 91 to 98, wherein: the means for moving the sample array relative to the fluid array includes means for moving the sample array relative to the fluid array while maintaining contact between the test surfaces and the bottom surfaces; and the means for detecting includes means for detecting an effect of friction and/or wear on the test samples.

101. The system of any of claims 91 to 100, wherein: the means for moving the sample array includes means for moving the sample array in an orbital pattern about an axis perpendicular to the bottom surfaces of the fluid array.

102. The system of any of claims 91 to 101, wherein: the means for detecting an effect includes means for analyzing the test surfaces for changes resulting from the moving.

103. The system of any of claims 91 to 102, wherein: the means for detecting an effect includes means for analyzing the test fluids for changes resulting from the moving.

104. The system of claim 103, wherein: the means for analyzing the test fluids includes means for analyzing the test fluids for the presence of elements or ions or a change in pH.

105. A system for screening compositions in a test environment, the system comprising: means for positioning a test sample in a each of a plurality of test cells; means for depositing a test fluid in each of the plurality of test cells; a shuttle capable of being positioned in each of the plurality of test cells, the shuttles defining a flow region along a surface of the test samples; means for moving each of the shuttles in the corresponding test cells to force a flow of the corresponding test fluid through the flow region; and means for detecting an effect of the test fluid flow on the test samples.

106. The system of claim 105, wherein: the test samples include one or more metals.

107. The system of either of claims 105 or 106, wherein: the test samples include one or more coatings or films.

108. The system of any of claims 105 to 107, wherein: the test samples include one or more materials used in a refinery process.

109. The system of any of claims 105 to 108, wherein: the test fluid includes a crude oil or crude oil fraction.

110. The system of any of claims 105 to 109, wherein: the test cells have a volume in the range of about 100 μl to about 5 ml.

111. The system of any of claims 105 to 110, further comprising: means for heating at least a portion of the test cells during the moving.

112. The system of any of claims 105 to 111, wherein: the shuttles are configured to define the flow region as an annular space around each of the test samples.

113. The system of any of claims 105 to 112, wherein: the means for moving the shuttle includes means for moving the shuttles in a reciprocating motion from a first end of the test cells to a second end of the test cells, and back.

114. The system of claim 113, wherein: the means for moving the shuttles includes means for driving the test shuttles by magnetic coupling.

115. The system of any of claims 105 to 114, wherein: the means for detecting an effect includes means for analyzing the test samples for changes resulting from the test fluid flow.

116. The system of claim 115, wherein: the means for analyzing the test samples includes means for analyzing the test samples for changes in a surface property or weight.

117. The system of any of claims 105 to 116, wherein: the means for detecting an effect includes means for analyzing the test fluid for changes resulting from the test fluid flow.

118. The system of claim 117, wherein: the means for analyzing the test fluid includes means for analyzing the test fluid for the presence of elements or ions or a change in pH.

119. The system of any of claims 105 to 118, wherein: the means for depositing a test fluid includes means for depositing a different test fluid in two or more of the plurality of test cells.

120. The system of any of claims 105 to 119, wherein: the means for positioning the test samples includes means for positioning a different test sample in two or more of the plurality of test cells.

121. The system of any of claims 105 to 120, wherein: the plurality of test cells includes a collection of test cells arranged in a reactor block.

122. The system of claim 121, wherein: the plurality of test cells includes a plurality of collections of test cells, each collection being arranged in one of a plurality of reactor blocks.

123. The system of any of claims 105 to 122, further comprising: means for heating the test cells during the moving.

124. A system for screening compositions in a test environment, the system comprising: means for providing an array including a substrate and a plurality of test samples mounted in or on the substrate, each of the test samples having a test surface; means for exposing the test surface of each of the plurality of test samples to a test environment; means for examining the test surface of each of the plurality of test samples by using a profilometry technique to detect changes resulting from exposure to the test environment.

125. The system of claim 124, wherein: the array includes a plurality of test samples each comprising a different material.

126. The system of either of claims 124 or 125, wherein: the plurality of test samples includes a plurality of test samples comprising the same material.

127. The system of any of claims 124 to 126, wherein: the plurality of test samples includes one or more metals.

128. The system of any of claims 124 to 127, wherein: the plurality of test samples includes one or more test samples having test surfaces formed by one or more coatings or films.

129. The system of any of claims 124 to 128, wherein: the array includes one or more standard samples mounted in or on the substrate, each of the standard samples having a standard surface; and the means for examining the test surfaces includes means for comparing the test surfaces to the standard surfaces.

130. The system of any of claims 124 to 129, wherein: the substrate has a surface; and the means for examining the test surfaces includes comparing the test surfaces to the substrate surface.

131. The system of any of claims 124 to 130, wherein: the means for exposing the test surface of each of the plurality of test samples to a test environment includes means for exposing two or more of the plurality of test surfaces to different test environments.

132. The system of any of claims 124 to 131, wherein: the means for exposing the test surfaces includes means for exposing the test surfaces to a gas phase environment.

133. The system of any of claims 124 to 131, wherein: the means for exposing the test surfaces includes means for exposing the test surfaces to a liquid phase environment.

134. The system of any of claims 124 to 133, wherein: the means for exposing the test surfaces includes means for exposing the test surfaces to a static gaseous or liquid environment.

135. The system of any of claims 124 to 133, wherein: the means for exposing the test surfaces includes means for stirring a liquid in contact with one or more of the test surfaces.

136. The system of any of claims 124 to 133 , wherein: exposing the test surfaces includes transporting a gas or liquid across one or more of the test surfaces by bulk flow.

137. The system of any of claims 124 to 133, wherein: the means for exposing the test surfaces includes means for transporting a gas or liquid across one or more of the test surfaces by reciprocating flow.

138. The system of any of claims 124 to 133, wherein: the means for exposing the test surfaces includes means for immersing the test surfaces in the test environment and moving the test surfaces in an orbital motion relative to the test environment.

139. The system of any of claims 124 to 138, wherein: the means for examining the test surfaces includes means for measuring a height difference for each of the test samples.

140. The system of any of claims 124 to 139, wherein: the means for examining the test surfaces includes means for measuring a roughness for each of the test surfaces.

141. The system of any of claims 124 to 140, wherein: the means for examining the test surfaces includes means for examining the test surfaces using a optical or contact profilometry.

142. The system of any of claims 124 to 140, wherein: the means for examining the test surfaces includes means for examining the test surfaces using atomic force microscopy or scanning electron microscopy.

143. A system for screening compositions in a test environment, the system comprising: a flow channel defining a flow path for a test fluid; a sample holder for positioning a test sample in the flow path; a pumping subsystem configured to provide for a reciprocating constant pressure- driven flow past a test sample positioned in the flow path; and a temperature control subsystem configured to heat the test fluid to a desired temperature in a region of the flow channel adjacent to the sample holder.

144. The system of claim 143, wherein: the sample holder is configured to position a plurality of test samples in the flow channel.

145. The system of claim 144, wherein: the plurality of test samples differ based on their constituent materials, coatings and/or surface treatments.

146. The system of either any of claims 143 to 145, wherein: the test samples include one or more materials used in a refinery process.

147. The system of any of claims 143 to 146, wherein: the flow channel has a volume in the range of about 0.5 ml to about 10 ml.

148. The system of any of claims 143 to 147, wherein: the pumping subsystem includes a pair of syringe pumps or diaphragm pumps.

149. The system of any of claims 143 to 148, wherein: the test fluid comprises a crude oil or crude oil fraction.

150. The system of any of claims 143 to 149, further comprising: an analysis subsystem for detecting an effect of corrosion resulting from exposure of the test samples to the test fluid.

151. The system of claim 150, wherein: the analysis subsystem is operable to analyze the test samples for changes resulting from the exposure.

152. The system of claim 151, wherein: the analysis subsystem includes a profilometer.

153. The system of claim 150, wherein: the analysis subsystem is operable to analyze the test fluid for changes resulting from the exposure.

154. The system of claim 153, wherein: the analysis subsystem includes an inductively coupled plasma spectrometer or an atomic absorption spectrometer.

155. The system of any of claims 143 to 154, further comprising: a plurality of flow channels defining flow paths for a plurality of test fluids; and a plurality of sample holders for positioning test samples in the plurality of flow paths; wherein the pumping subsystem is configured to provide for a reciprocating constant pressure-driven flow past test samples positioned in each of the plurality of flow paths.

156. The system of claim 155, wherein: a different test sample is positioned in two or more of the plurality of flow channels.

157. The system of either of claims 155 or 156, wherein: a different test fluid is disposed in two or more of the plurality of flow channels.

158. The system of any of claims 155 to 157, wherein: the pumping subsystem includes a pair of syringe pumps or diaphragm pumps in communication with each of the plurality of flow paths.

159. A system for screening compositions in a test environment, the system comprising: a fluid array including a plurality of wells, each of the plurality of wells - containing a test fluid; a sample array including a substrate and a plurality of test samples mounted in or on the substrate, each of the test samples having a test surface, the test samples being immersed in the fluid array wells to expose the test surfaces to the test fluids, the test samples and fluid array wells being positioned to define a spatial relationship between each test surface and a bottom surface of the corresponding well; a motion subsystem operable to move the sample array relative to the fluid array while maintaining the spatial relationship between the test surfaces and bottom surfaces; and a detector for detecting an effect of the moving on the test samples or the test fluids.

160. The system of claim 159, wherein: the sample array includes a plurality of different test samples.

161. The system of either of claims 159 or 160, wherein: the test samples include one or more metals.

162. The system of any of claims 159 to 161, wherein: the test samples include one or more coatings or films.

163. The system of any of claims 159 to 162, wherein: the test samples include one or more materials used in a refinery process.

164. The system of any of claims 159 to 163, wherein: the fluid array includes a plurality of different test fluids.

165. The system of any of claims 159 to 164, wherein: the test fluids comprise one or more crude oils or crude oil fractions.

166. The system of any of claims 159 to 165, wherein:

, each of the test samples has one or more side surfaces, and each of the plurality of wells has an internal surface, the side surfaces and the internal surfaces being coated with one or more inert materials.

167. The system of any of claims 159 to 166, wherein: the motion subsystem is operable to move the sample array relative to the fluid array while maintaining a defined gap between the test surfaces and the bottom surfaces to create a controlled wall shear stress at the test surface.

168. The system of any of claims 159 to 166, wherein: the motion subsystem is operable to move the sample array relative to the fluid array while maintaining a contact between the test surfaces and the bottom surfaces to create friction and/or wear at the test surface.

169. The system of any of claims 159 to 168, wherein: the motion subsystem is operable to move the sample array in an orbital pattern about an axis perpendicular to the bottom surfaces of the fluid array.

170. The system of any of claims 159 to 169, further comprising: an analysis subsystem for detecting an effect of corrosion resulting from exposure of the test samples to the test fluids.

171. The system of claim 170, wherein: the analysis subsystem is operable to analyze the test samples for changes resulting from the exposure.

172. The system of claim 171, wherein: the analysis subsystem includes a profilometer.

173. The system of claim 170, wherein: the analysis subsystem is operable to analyze the test fluid for changes resulting from the exposure.

174. The system of claim 173, wherein: the analysis subsystem includes an inductively coupled plasma spectrometer or an atomic absorption spectrometer.

180. A system for screening compositions in a test environment, the system comprising: a reactor block including a plurality of test cells, each of the test cells being configured to receive a test fluid and a test sample; a plurality of shuttles configured to fit in the plurality of test cells, each of the plurality of shuttles being shaped to define, when positioned in one of the plurality of test cells, a flow region along a surface of a test sample positioned in one of the plurality of test cells, each of the plurality of shuttles including a magnet; and a magnetic coupling system for driving the shuttle in a reciprocating motion along a length of the test cell.

181. The system of claim 180, wherein: the test samples include one or more metals.

182. The system of either of claims 180 or 181 , wherein: the test samples include one or more coatings or films.

183. The system of any of claims 180 to 182, wherein: the test samples include one or more materials used in a refinery process.

184. The system of any of claims 180 to 183, wherein: the test fluid includes a crude oil or crude oil fraction.

185. The system of any of claims 180 to 184, wherein: the test cells have a volume in the range of about 100 μl to about 5 ml.

186. The system of any of claims 180 to 185, further comprising: a temperature control subsystem configured to heat at least a portion of the test cells.

187. The system of any of claims 180 to 186, wherein: each of the plurality of shuttles defines the flow region as an annular space around the corresponding test sample.

188. The system of any of claims 180 to 187, further comprising: an analysis subsystem for detecting an effect of corrosion resulting from exposure of the test samples to the test fluids.

189. The system of claim 188, wherein: the analysis subsystem is operable to analyze the test samples for changes resulting from the exposure.

190. The system of claim 189, wherein: the analysis subsystem includes a profilometer.

191. The system of claim 188, wherein: the analysis subsystem is operable to analyze the test fluid for changes resulting from the exposure.

192. The system of claim 191, wherein: the analysis subsystem includes an inductively coupled plasma spectrometer or an atomic absorption spectrometer.

193. The system of any of claims 180 to 192, wherein: two or more of the plurality of test cells contain different test fluids.

194. The system of any of claims 180 to 193 , wherein: two or more of the plurality of test cells contain different test samples.

195. The system of any of claims 180 to 194, wherein: the plurality of test cells includes a collection of test cells arranged in a reactor block.

196. The system of claim 195, wherein: the plurality of test cells includes a plurality of collections of test cells, each collection being arranged in one of a plurality of reactor blocks.