+

WO1994009253A1 - Composition destinee au forage et a l'entretien de puits - Google Patents

Composition destinee au forage et a l'entretien de puits Download PDF

Info

Publication number
WO1994009253A1
WO1994009253A1 PCT/EP1993/002346 EP9302346W WO9409253A1 WO 1994009253 A1 WO1994009253 A1 WO 1994009253A1 EP 9302346 W EP9302346 W EP 9302346W WO 9409253 A1 WO9409253 A1 WO 9409253A1
Authority
WO
WIPO (PCT)
Prior art keywords
acid
composition
filtercake
salt
alkali metal
Prior art date
Application number
PCT/EP1993/002346
Other languages
English (en)
Inventor
Lars KASTHOLM KRISTIANSEN
Original Assignee
Gait Products Limited
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Gait Products Limited filed Critical Gait Products Limited
Publication of WO1994009253A1 publication Critical patent/WO1994009253A1/fr

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
    • C09K8/60—Compositions for stimulating production by acting on the underground formation
    • C09K8/84—Compositions based on water or polar solvents
    • C09K8/86—Compositions based on water or polar solvents containing organic compounds
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
    • C09K8/42—Compositions for cementing, e.g. for cementing casings into boreholes; Compositions for plugging, e.g. for killing wells
    • C09K8/424—Compositions for cementing, e.g. for cementing casings into boreholes; Compositions for plugging, e.g. for killing wells using "spacer" compositions
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
    • C09K8/52—Compositions for preventing, limiting or eliminating depositions, e.g. for cleaning

Definitions

  • the present invention relates to a composition for use in the drilling and maintenance of wells, particularly oil and gas wells.
  • drilling fluid is introduced into the descending bore formed by the drill head.
  • the drilling fluid serves to lubricate the bore and drill head.
  • the drilling fluid which is commonly referred to as drilling mud, deposits a lining on the walls of the bore, the lining being comprised of the solid components of the drilling mud. This deposited lining is known as filtercake.
  • stuck pipe additives themselves raise an additional problem.
  • Most stuck pipe additives are petroleum based surfactants which need to be blended with an oil in order to carry out their function effectively. Accordingly, environmental concerns have led to the outright banning of these substances or to the regulation of their use under stringent and expensive control criteria.
  • the next step is that the casing is fixed to the walls of the bore by cement.
  • the presence of the filtercake lining the bore raises another difficulty at this stage, as it decreases the efficiency of the bonding between the bore wall, cement and casing.
  • US-A-4609475 in the name of Halliburton Company discloses an aqueous composition for removing polymeric materials from a subterranean formation.
  • the composition includes a water soluble carboxylic acid such as citric acid, and an alkali metal salt as an oxidising agent.
  • GB-1494448 in the name of Shell Internationale Research Maatschappij B.V. there is described an aqueous solution including a weak acid for acidizing subterranean formations.
  • the solution includes a fluoride salt, a weak acid and a weak acid salt to lower hydrogen fluoride concentration, thereby to avoid the reaction of acid with carbonates to form precipitates.
  • the acid may be citric acid and the salt may be sodium, potassium or ammonium acetate, formate or citrate.
  • a similar disclosure is made in GB-1495841, also in the name of Shell International Research Maatschappij B.V., with the omission of the fluoride salt from the solution.
  • GB-A-2174435 in the name of Amerigo Technology Limited discloses means for improving recovery from a well by flushing in a strong acid, followed by a solution of an acid such as citric acid, a surfactant and a clay stabilizer. Use is made of potassium chloride as the clay stabilizer.
  • the present invention provides a composition effective to dissolve filtercake in a well bore, the composition comprising one or more water soluble organic acids in an aqueous solution of one or more of a salt selected from alkali metal chloride, alkali metal formate, acid tetraphosphate, alkaline earth chloride, alkali metal thiosulphate or the like.
  • a salt selected from alkali metal chloride, alkali metal formate, acid tetraphosphate, alkaline earth chloride, alkali metal thiosulphate or the like.
  • the present invention also provides a dry powder mixture for use in the preparation of an aqueous composition which is effective to dissolve filtercake in a well bore, the mixture comprising a salt of one or more water soluble organic acids and one or more of a salt selected from alkali metal chloride, alkali metal formate, acid tetraphosphate, alkaline earth chloride, alkali metal thiosulphate or the like.
  • the constituents of the composition may conveniently be supplied as a dry powder mixture, with instructions given as to how the powder should be reconstituted in the field for use.
  • Supply of the material in dry form is more economical for the manufacturer, whose packaging, transport and other costs will be lower than for supply of the aqueous composition.
  • the water soluble acid comprises 0.5% to 75% w/w of the composition, and preferably 10% to 35%.
  • the salt comprises 0.5% to 75% w/w of the composition, and preferably 10% to 35%.
  • the water soluble organic acid is selected from the group comprising citric acid, oxalic acid, ascorbic acid, succinic acid, malonic acid, maleic acid and lactic acid, or any combination thereof, in any ratio
  • the salt is selected from the group comprising potassium chloride, sodium chloride, magnesium chloride, sodium acid tetraphosphate, sodium thiosulphate pentahydrate, sodium formate, potassium formate and cesium formate, or any combination thereof, in any ratio.
  • the composition conveniently includes an alkali metal pyrophosphate salt, preferably sodium acid pyrophosphate.
  • the most preferred embodiment comprises 200 to 230g citric acid monohydrate and 200 to 235g potassium chloride per litre of water and preferably further includes 15 to 25g sodium acid pyrophosphate per litre of water.
  • the invention further provides the uses of the above composition as (1) a filtercake dissolving additive in the drilling and maintenance of wells, (2) a fixer spacer in the drilling of wells, and (3) a stimulating fluid for blocked or partially blocked oil or gas wells.
  • composition according to the invention dehydrates clay particles in the drilling fluid filtercake. It further solubilises any entrained carbonates in the filtercake, thereby destroying the matrix integrity that binds the filtercake together. Polymers in the filtercake are destroyed by acid hydrolysis thereby further solubilising the filtercake components.
  • the effect of the composition of the present invention is to solubilise filtercake, after which the non-toxic aqueous composition containing filtercake residue can be flushed from the bore and disposed of without causing any particular environmental hazard.
  • the invention further provides a method of freeing stuck pipes in the drilling of well bores, the method comprising introducing a composition of the invention as described above into the bore in the region of the stuck pipe so as to dissolve and remove filtercake adhering to the pipe.
  • the method is very simple to use and is completely safe for personnel as the composition contains only non-hazardous components, citric acid and other organic acids being mild acids and potassium chloride being an innocuous salt.
  • Citric acid has formerly been used in well-drilling applications on a very limited scale for lowering the pH of drilling mud.
  • Potassium chloride has been used in small quantities to inhibit the swelling of drilling mud by water absorption. The use of these two components in aqueous solution as a solvent for filtercake has never been heretofore suspected or recognised.
  • the invention still further provides a composition as described above for use as a fixer spacer in the drilling of wells.
  • a composition as described above for use as a fixer spacer in the drilling of wells.
  • the presence of filter cake deposits on the walls of the bore and pipes often results in poor cement adhesion of the pipe into the well.
  • This problem can be overcome by using the composition of the invention as a spacer between the pipe and the bore walls. Once pumped in, the composition will dissolve the filtercake from the surfaces to be fixed by a fixer compound such as cement or the like, after which the cement can be introduced into the space between the cleaned surfaces. This results in an effective bond of the pipes in the bore.
  • the invention also provides a method for securely fixing well casing pipe in a well bore, the method comprising introducing the composition of the invention as described above into the space between the pipe and the bore walls, allowing the composition to dissolve filtercake from the said space and introducing a fixer compound to displace the composition and dissolved filtercake residues.
  • the fixer may be cement or any other suitable fixing compound.
  • compositions as described above for use as a stimulating fluid for blocked or partially blocked oil or gas wells.
  • the composition is capable of stimulating oil or gas production from wells by dissolving filtercake from the pores in the sub-stratum through which the oil or gas flows into the well.
  • the invention further provides a method for stimulating production from an oil or gas well, comprising introducing into the well an amount of the composition of the present invention effective to unblock gas or oil supply pores by dissolving blocking filtercake therefrom.
  • the composition employs a near saturation level of dissolved salt, preferably a potassium salt, to provide a highly destabilizing electrolytic environment.
  • the level of cation available is such that the diffuse area near the surface of the clay crystals themselves becomes compressed (the thickness of this diffuse area (Gouy layer) is proportional to the concentration of electrolyte present) .
  • the concentration of electrolyte is such that Born repulsion is overcome. This repulsion, which would normally prevent an interpenetration of the crystal lattices, is overcome forcing the destabilizing results of (a) desorbtion of water from the faces of the clay and (b) cationic exchange within the clay matrix of the native clay ion (normally sodium or calcium) with the potassium ion.
  • potassium inhibited drilling fluids are occasionally used as clay stabilizers in drilling suitable formations, the cation is provided in a slight excess, rather than in the high concentration which would result in destabilisation. That is to say, the level of potassium in solution is aimed at an "ideal balance" or stabilizing situation and destabilising levels are particularly avoided. As such, in many instances, the level of potassium in the drilling fluid is constantly being consumed but remains in slight excess to provide the raw material for the ion exchange.
  • the composition of the invention forces a physical ionic change in the equilibrium of the filtercake environment.
  • the potassium ion when present in basal exchange sites which are in a dehydrated state, occupies less area than the calcium and magnesium ions which are present in hydrated states.
  • potassium ion occupies far less area than the calcium, magnesium or sodium ions in the same clay crystals. This combined with the de-watering, creates fissures, cracks and blisters in the uniform surfaces that have been created in the stable environment. The clay matrix losses its integrity, cohesion and literally and figuratively crumbles. 2. Acid Dissolution
  • the invention reverses this trend by using the composition of the invention to remove entrained and adsorbed contaminants which result from exposure to the drilling fluid through (a) the destructive use of high electrolytic fluids to crack acid insoluble clay surfaces thereby allowing (b) exposure to the acid solution of carbonates embedded in the filtercake matrix which in turn (c) exposes new clay faces to electrolytic desorbtion of water and cationic exchange all of which results in (d) the removal of the cracked and shrinking clay particles, and dissolved polymeric remnants by the expanding carbon dioxide gas residues formed in the acidization of the carbonates and polymers.
  • the inclusion of the acid is viable as it is known that the pH of the fluid does not effect the ion exchange capacity of clays.
  • the validity of the acid inclusion is verified by laboratory tests on many lab and field muds, as exemplified in the Examples, which verify that lab muds containing low levels of raw polymers, high levels of American Petrolium Institute (API) commercial bentonite, and low levels of API commercial barite, are relatively unaffected by the inventive composition, showing only some cracking and blistering and no actual removal of mud. This indicates that no carbonate material is available for the gas disruption or solubilization of polymers beneath the surface in the test frame of 60 minutes. The same formulation however taken from a field mud, shows immediate blistering, bubble formation, and filtercake lifting within 30 minutes.
  • API American Petrolium Institute
  • the methodology entailed placing the relevant mud samples in the liquid chamber of the filtercake apparatus, beneath which has been placed a 7.6 cm (3 inch) circular sheet of Whatman No. 50 filterpaper.
  • the covering was placed over the liquid container vessel and the chamber pressured to 150 psi using gas cartridges, and sustained for 60 minutes.
  • the chamber was then depressurised, and the whole mud decanted.
  • the filter paper with the filtercake was removed, and gently washed with fresh water to remove excess whole mud.
  • the thickness of the filtercakes was dependent on the mud types, but were on average 0.8 to 1.6 mm (1/32 to 1/16 inch) thick.
  • the type of muds tested are as noted in Table 1. All muds were seawater-waterbased muds.
  • MBT Methylene Blue Equivalents (cation exchange capacity of the clays present in the drilling fluid).
  • the MBT value is noted, with the bentonite which was reported as being added by the drilling fluid supplier, so as to calculate how much clay is of formation origin.
  • the polymers are from the polyacrylamides groups, and high temperature stable vinyl - copolymer groups; the dispersants noted are lignosulfonate and lignin resins.
  • Example 2 Evaluation of salts and acids The testing and evaluation consisted of determining, A) which salts, within a selected solubility range were most destructive and B) the most destructive and soluble acids within a joint compatibility solubility range with the salts.
  • Each filtercake was made and was fixed with an inert fixative to the bottom of a petri dish to prevent flotation.
  • the test solution was added then decanted using gentle suction, and fresh fluid added, at 10 minute intervals over 1 hour, with a determination of results made at the end of that period.
  • the base line was determined from physical change in filtercakes in independent testing of each salt and acid. Then the same determination was made for the combination of the two most compatible salts and acids.
  • the secondary selection criterion was evaluation of a formulation's reaction with a formation (mud), versus potential environmental impact of the spent resultant product.
  • the human safety factor was taken into account, as the products were selected for testing based on human working conditions and safety limitations, including effect of disposal of used composition by release into the environment.
  • Table 2 lists the maximum concentrations of salts used to achieve any or in some cases, a maximum effect.
  • citric acid used was 99.9% citric acid monohydrate. The amounts added were dependent on solubility in the various brines. Other acids were tested in the same manner. The amounts of acids used were solubility related to the brine test solutions in Series 1 (Table 1 ) .
  • citric acid gave the best results with potassium chloride.
  • Citric acid/magnesium chloride and phosphoric acid/potassium or magnesium chloride combinations were also very useful, but in the latter case, required very high concentrations of phosphoric acid ( > 35% w/w) .
  • Formulation A (example 2) was tested against a commonly used, commercially available free-pipe additive, hydrochloric acid (15% in CaCl 2 brine), and the next best test formulation, namely phosphoric acid (30% w/w) in KCl (20% w/w) as a control.
  • phosphoric acid (30% w/w) in KCl (20% w/w) as a control.
  • acetic acid (35% in saturated CaCl2 brine) was run.
  • the free pipe additive used was Pipelax (manufactured by M.I. Drilling Fluids), blended with Diesel oil as per the suppliers recommended instructions.
  • Formulation A Example 2
  • 1.5 cm thick sandstone cores were used.
  • the cores were cut longitudinally into sections designed to fit into a pressure chamber for impregnating filtercakes on cores to 2000 psi.
  • the cores were flushed and cleaned with methanol and dried.
  • each core plug was established using North Sea Brent crude oil. 2. The core plugs were rewashed and dried.
  • the core was again pressured (B>W) to 1000 psi and held for 15 minutes.
  • the core plug was then reversed pressurized using crude oil from the chamber opposite the well bore side (W), and the crude allowed to flow back in the direction (W>B).
  • Formulation A 50.80% 52.80% 15% HCL 40.80% 38.80%
  • Base P Base permeability in mD
  • Return P Return Permeability in mD.
  • composition A preferred formulation of the composition is prepared as follows:
  • Citric acid monohydrate 217 grams
  • composition is suitable for use in all the applications described above.
  • formulation A (example 2).
  • the formulation was found to have low toxicity when measured on the standard marine test species Acartia tonsa and Skeletonema costatum, using the protocols adopted by PARCOM and the regulatory agencies in the signatory governments (including MAFF in the U.K., SFT in Norway and the Inpectorate of Mines in the Netherlands).
  • the formulation was found to be readily biodegradable (100% aerobic degradation in 5 days, as measured according to the OECD guideline 306 for the measurement of marine degradability) .

Landscapes

  • Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Solid-Sorbent Or Filter-Aiding Compositions (AREA)

Abstract

Une composition servant à dissoudre des dépôts de gâteau de filtration produits par la boue de forage dans des puits, comprend une solution aqueuse d'un acide organique soluble dans l'eau et sel choisi entre du chlorure de métal alcalin, du formate de métal alcalin, du tétraphosphate acide, du chlorure alcalino-terreux ou du thiophosphate de métal alcalin. L'acide et le sel sont chacun présents en une teneur comprise entre 0,5 % et 75 % en poids basé sur le poids de la composition. L'acide préféré est l'acide citrique, et le sel préféré est le chlorure de potassium. La composition peut être utilisée comme un additif pour libérer des conduits bloqués dans des puits, ainsi que comme un élément d'espacement d'agent de fixation permettant de cimenter le conduit dans des puits. Elle peut en outre être utilisée comme fluide d'activation dans des puits de production de pétrole et de gaz, la composition permettant de dissoudre des gâteaux de filtration qui bloquent les pores dans la formation.
PCT/EP1993/002346 1992-10-21 1993-08-30 Composition destinee au forage et a l'entretien de puits WO1994009253A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IE922758 1992-10-21
IES922758 1992-10-21

Publications (1)

Publication Number Publication Date
WO1994009253A1 true WO1994009253A1 (fr) 1994-04-28

Family

ID=11039782

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP1993/002346 WO1994009253A1 (fr) 1992-10-21 1993-08-30 Composition destinee au forage et a l'entretien de puits

Country Status (3)

Country Link
BR (1) BR9304300A (fr)
MX (1) MX9306470A (fr)
WO (1) WO1994009253A1 (fr)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5785747A (en) * 1996-01-17 1998-07-28 Great Lakes Chemical Corporation Viscosification of high density brines
FR2771444A1 (fr) * 1997-11-26 1999-05-28 Schlumberger Cie Dowell Amerioration du placement de coulis de ciment dans les puits en presence de zones geologiques contenant des argiles gonflantes ou de restes de boue contenant des argiles
US6015535A (en) * 1995-04-06 2000-01-18 Cabot Corporation Process for producing purified cesium compound from cesium alum
US6100222A (en) * 1996-01-16 2000-08-08 Great Lakes Chemical Corporation High density, viscosified, aqueous compositions having superior stability under stress conditions
WO2002006422A3 (fr) * 2000-07-14 2002-05-23 Cabot Specialty Fluids Inc Compositions permettant de commander des fluides d'ecaillage et de completion
US6818595B2 (en) 2001-02-14 2004-11-16 Cabot Specialty Fluids, Inc. Drilling fluids containing an alkali metal formate
CN105525890A (zh) * 2015-11-24 2016-04-27 中国石油化工股份有限公司 用于筛管完井水平井堵水的方法
US10577300B2 (en) 2018-06-12 2020-03-03 Saudi Arabian Oil Company Synthesis of sodium formate and drilling fluid comprising the same
EP4098715A1 (fr) * 2021-06-01 2022-12-07 EnBW Energie Baden-Württemberg AG Procédé de dégagement d'un forage profond obstrué par un adsorbant
CN117603669A (zh) * 2024-01-24 2024-02-27 北京石大瑞伽石油技术开发有限公司 一种油、气、水井综合解堵剂及其使用方法

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3135325A (en) * 1959-12-18 1964-06-02 Phillips Petroleum Co Water flooding technique
US4067389A (en) * 1976-07-16 1978-01-10 Mobil Oil Corporation Hydraulic fracturing technique
EP0326720A1 (fr) * 1988-02-05 1989-08-09 ENIRICERCHE S.p.A. Méthode pour enlever des gels de polymères d'un réservoir de pétrole

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3135325A (en) * 1959-12-18 1964-06-02 Phillips Petroleum Co Water flooding technique
US4067389A (en) * 1976-07-16 1978-01-10 Mobil Oil Corporation Hydraulic fracturing technique
EP0326720A1 (fr) * 1988-02-05 1989-08-09 ENIRICERCHE S.p.A. Méthode pour enlever des gels de polymères d'un réservoir de pétrole

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6436879B1 (en) 1995-04-06 2002-08-20 Cabot Corporation Process for producing a predetermined cesium compound
US6015535A (en) * 1995-04-06 2000-01-18 Cabot Corporation Process for producing purified cesium compound from cesium alum
US6100222A (en) * 1996-01-16 2000-08-08 Great Lakes Chemical Corporation High density, viscosified, aqueous compositions having superior stability under stress conditions
US5785747A (en) * 1996-01-17 1998-07-28 Great Lakes Chemical Corporation Viscosification of high density brines
FR2771444A1 (fr) * 1997-11-26 1999-05-28 Schlumberger Cie Dowell Amerioration du placement de coulis de ciment dans les puits en presence de zones geologiques contenant des argiles gonflantes ou de restes de boue contenant des argiles
WO1999027225A1 (fr) * 1997-11-26 1999-06-03 Sofitech N.V. Amelioration apportee a la mise en place de lait de ciment dans des puits en presence de zones geologiques contenant des argiles gonflantes ou des residus de boue contenant des argiles
AU2001273291B2 (en) * 2000-07-14 2007-03-01 Cabot Specialty Fluids, Inc. Compositions for controlling scaling and completion fluids
WO2002006422A3 (fr) * 2000-07-14 2002-05-23 Cabot Specialty Fluids Inc Compositions permettant de commander des fluides d'ecaillage et de completion
US7211550B2 (en) 2000-07-14 2007-05-01 Cabot Corporation Compositions for controlling scaling and completion fluids
US6818595B2 (en) 2001-02-14 2004-11-16 Cabot Specialty Fluids, Inc. Drilling fluids containing an alkali metal formate
CN105525890A (zh) * 2015-11-24 2016-04-27 中国石油化工股份有限公司 用于筛管完井水平井堵水的方法
CN105525890B (zh) * 2015-11-24 2019-01-08 中国石油化工股份有限公司 用于筛管完井水平井堵水的方法
US10577300B2 (en) 2018-06-12 2020-03-03 Saudi Arabian Oil Company Synthesis of sodium formate and drilling fluid comprising the same
US10919833B2 (en) 2018-06-12 2021-02-16 Saudi Arabian Oil Company Synthesis of sodium formate and drilling fluid comprising the same
EP4098715A1 (fr) * 2021-06-01 2022-12-07 EnBW Energie Baden-Württemberg AG Procédé de dégagement d'un forage profond obstrué par un adsorbant
US12018208B2 (en) 2021-06-01 2024-06-25 EnBW Energie Baden-Württemberg AG Method for unblocking a deep well plugged by an adsorbent
CN117603669A (zh) * 2024-01-24 2024-02-27 北京石大瑞伽石油技术开发有限公司 一种油、气、水井综合解堵剂及其使用方法
CN117603669B (zh) * 2024-01-24 2024-04-19 北京石大瑞伽石油技术开发有限公司 一种油、气、水井综合解堵剂及其使用方法

Also Published As

Publication number Publication date
BR9304300A (pt) 1994-04-26
MX9306470A (es) 1994-05-31

Similar Documents

Publication Publication Date Title
US7549474B2 (en) Servicing a wellbore with an aqueous based fluid comprising a clay inhibitor
US7854277B2 (en) Wellbore fluid comprising a base fluid and a particulate bridging agent
CA2088581C (fr) Achevement et reconditionnement des puits de gaz et de petrole
US4526693A (en) Shale and salt stabilizing drilling fluid
EP0960259A1 (fr) Fluide de forage et d'entretien d'un puits contenant des aphrons
NO339481B1 (no) Vannbasert boreslam med høy ytelse og fremgangsmåte for anvendelse
US11535794B1 (en) Viscoelastic surfactant-based treatment fluids for use with lost circulation materials
WO2017075348A1 (fr) Pilule contre la perte de fluide à base de polymères synthétiques
US20070207932A1 (en) Clay inhibitors for the drilling industry
WO1994009253A1 (fr) Composition destinee au forage et a l'entretien de puits
CA2656513A1 (fr) Additif pour tige de forage coincee et procede
US5309997A (en) Well fluid for in-situ borehole repair
CA2594173C (fr) Additifs contenant du silicate pour traitement de puits de forage et procedes associes
WO2006060388A2 (fr) Additif de fluide de forage, et procede
MX2013000415A (es) Fluido de perforacion y metodo para perforar un pozo.
IES930633A2 (en) Composition for use in well drilling and maintenance
CA2594208C (fr) Additifs contenant du silicate pour traitement de puits de forage et procedes associes
US7137459B1 (en) Silicate drilling fluid and method of drilling a well therewith
AU2021201364B2 (en) Drill fluid and method for tunneling
US11155742B2 (en) Drill fluid and method for tunneling
Austin Drilling Fluids
US20100222241A1 (en) Clay Inhibitors for the Drilling Industry
GB2255993A (en) Method for releasing a stuck pipe

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): BR CA NO RU US VN

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB GR IE IT LU MC NL PT SE

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
121 Ep: the epo has been informed by wipo that ep was designated in this application
122 Ep: pct application non-entry in european phase
NENP Non-entry into the national phase

Ref country code: CA

点击 这是indexloc提供的php浏览器服务，不要输入任何密码和下载