WO2008139164A1 - Methods for stimulating oil or gas production - Google Patents
Methods for stimulating oil or gas production Download PDFInfo
- Publication number
- WO2008139164A1 WO2008139164A1 PCT/GB2008/001615 GB2008001615W WO2008139164A1 WO 2008139164 A1 WO2008139164 A1 WO 2008139164A1 GB 2008001615 W GB2008001615 W GB 2008001615W WO 2008139164 A1 WO2008139164 A1 WO 2008139164A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- treatment fluid
- viscosity
- chelating agent
- water
- concentration
- Prior art date
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
- C09K8/52—Compositions for preventing, limiting or eliminating depositions, e.g. for cleaning
- C09K8/528—Compositions for preventing, limiting or eliminating depositions, e.g. for cleaning inorganic depositions, e.g. sulfates or carbonates
-
- 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
- C09K2208/00—Aspects relating to compositions of drilling or well treatment fluids
- C09K2208/30—Viscoelastic surfactants [VES]
Definitions
- the invention generally relates to production enhancement to increase hydrocarbon production from a subterranean formation. More particularly, the invention relates to methods of treating a portion of a matrix of a subterranean formation or a proppant pack in a pre-existing fracture or perforation to increase permeability and enhance production, some of which techniques are referred to as near-wellbore stimulation. More particularly also, the invention relates to methods of treating downhole wellbore tubulars or subsurface completion equipment for mineral deposits, which deposits are generally referred to as scale, and especially for deposits containing calcium carbonate.
- a method for treating a portion of a subterranean formation or a proppant pack comprises the steps of: (A) forming or providing a treatment fluid comprising: (i) water; (ii) a chelating agent capable of forming a heterocyclic ring that contains a metal ion attached to at least two nonmetal ions; and (iii) a viscosity-increasing agent; and (B) introducing the treatment fluid into the wellbore under sufficient pressure to force the treatment fluid into the matrix of the formation or the proppant pack.
- a method for treating at least a portion of a downhole wellbore tubular or subsurface completion equipment comprises the steps of: (A) determining the likelihood of the presence of scale in the wellbore tubular or the subsurface completion equipment; (B) forming or providing a treatment fluid comprising: (i) water; (ii) a chelating agent capable of forming a heterocyclic ring that contains a metal ion attached to at least two nonmetal ions; and (iii) a viscosity-increasing agent; and (C) introducing the treatment fluid into the wellbore tubular or subsurface completion equipment.
- the purpose of this invention is to improve delivery of a chelating agent for production enhancement by increasing the viscosity of the treatment fluid.
- a chelating agent can be utilized to help dissolve and remove carbonates and other minerals from the matrix of the subterranean formation or the proppant pack. The concentration of the chelating agent is sufficient to help dissolve a substantial amount of carbonate material.
- the treatment fluid containing the chelating agent includes a viscosity-increasing agent to help with placement of the fluid into the formation or proppant pack or to help with diversion of the treatment fluid. When the viscosity of the fluid is increased or gelled, the treatment fluid can provide better coverage and diversion, and thereafter be broken for flowback from the well.
- the treatment fluid can be a single fluid that dissolves calcium/magnesium/iron carbonate solids in the matrix of the near region surrounding a wellbore, a pre-existing gravel pack, a pre-existing perforation, or a pre-existing fracture or that dissolves these solids in a proppant pack in a pre-existing perforation or a pre-existing fracture.
- the treatment fluid dissolves such solids at a controlled rate and under a wide range of conditions, especially over a broad range of pH and time.
- the invention can be advantageous because it can provide methods for treating the matrix of a subterranean formation or a pre-existing proppant pack for such purposes using treatment fluids that are non-acid containing and non-corrosive.
- the treatment methods according to the invention are expected to be effective for applications associated with well completion and remediation, including: removal of carbonate scale from the formation and fractures in the formation; removal of carbonate from formations or proppant packs where the carbonate lines pore throats; stimulation for carbonate containing formations where the use of acidic fluids might be problematic, for example, in high-temperature formations due to reaction rates, or due to corrosion, etc.
- a stimulation treatment the purpose is to improve the skin of the matrix of the formation over its original condition, and a greater depth of matrix penetration is desirable.
- the treatment method is used as a remedial cleanup after a prior stimulation treatment.
- the new approach is a method for treating a portion of a subterranean formation or proppant pack, the method comprising the steps of: (A) forming or providing a treatment fluid comprising: (i) water; (ii) a chelating agent capable of forming a heterocyclic ring that contains a metal ion attached to at least two nonmetal ions; and (iii) a viscosity-increasing agent; and (B) introducing the treatment fluid into the wellbore under sufficient pressure to force the treatment fluid into the matrix of the formation or the proppant pack.
- into the matrix of the formation or the proppant pack means into the rock around the wellbore, a pre-existing perforation, or a pre-existing fracture, or into the matrix of a proppant pack in a gravel pack in the wellbore, a pre-existing perforation, or a pre-existing fracture.
- the method is adapted to be used after drilling a wellbore, either during completion or remediation of a well.
- the chelating agent in the treatment fluid can react with and dissolve calcium carbonate, magnesium carbonate, dolomite, iron carbonate, and similar materials of the formation to increase the permeability of the formation. It can also be used to help remove carbonate from formations where the carbonate lines the pore throats in the matrix of the formation, whereby the permeability of the formation can be increased and hydrocarbon production enhanced. It is desirable to allow the treatment fluid to contact the matrix of the formation or the proppant pack for a sufficient time to dissolve such carbonate materials.
- CaCO 3 is known as limestone; and CaMg(CO 3 ) 2 is known as dolomite or dolomitic limestone, both of which are minerals that are often present in subterranean formations or which may precipitate from water as scale in subterranean formations or proppant packs.
- Typical scales are of calcium carbonate, calcium sulfate, barium sulfate, strontium sulfate, iron sulfide, iron oxides, iron carbonate, various silicates and phosphates and oxides, or any of a number of compounds insoluble or slightly soluble in water.
- the chelating agent can be helpful in removing calcium carbonate, magnesium carbonate, dolomite, iron carbonate, and similar materials of scale.
- Scale can be comprised of various mineral component deposits that can form over the inner walls of downhole casing, production tubing, and completion equipment, such as valves, gas- lift mandrels, and fluid pumps. Scale can be deposited along water paths in a subterranean formation, through wellbore tubulars, to surface equipment and surface tubulars. The scale can become so voluminous that it clogs the downhole wellbore tubulars or downhole equipment.
- Scale in the oil field environment can be formed as a result of mixing two incompatible waters downhole to create produced water that is oversaturated with scale-forming minerals. Scale can also be formed when the state of the water being produced is changed such that the solubility limit for one or more mineral components is exceeded.
- the solubility limit of each mineral component in an aqueous solution has a complex relationship to several factors, including temperature, pressure, the concentrations of other mineral components in solution, and pH. In general, but not for all minerals, a decrease in temperature tends to decrease the water solubility of the mineral. Similarly, a substantial decrease in pressure tends to decrease the water solubility of a mineral. Further, the solubility of a mineral can be impacted by the concentrations of other minerals in the solution.
- solubility of certain minerals is also increased in the presence of acid gases such as carbon dioxide and hydrogen sulfide, where carbonate solubility tends to increase as with increasing acidity.
- acid gases such as carbon dioxide and hydrogen sulfide at high pressure can make water quite acidic. Water containing such gases produced from a subterranean formation containing carbonate rock can have a high concentration of dissolved carbonate.
- the temperature tends to decrease and the pressure can also be decreased, both of which changes can contribute to precipitating minerals from the water to form scale in downhole wellbore tubulars and equipment.
- carbon dioxide or hydrogen sulfide may also be released, allowing the pH of the produced water to rise.
- Such changes can cause scale deposits.
- so much scale can be deposited that the scale blocks the fluid flow path through the downhole wellbore tubulars or equipment, and even downstream in surface tubulars and equipment.
- the invention in another aspect, relates to improving delivery of a chelating agent and the flowing back of the fluid for scale removal by increasing the viscosity of the treatment fluid.
- a chelating agent can be utilized to help dissolve and remove carbonates and other minerals from a wellbore tubular.
- the concentration of the chelating agent is sufficient to help dissolve a substantial amount of carbonate material.
- the treatment fluid containing the chelating agent includes a viscosity-increasing agent to help with placement of the treatment fluid and to help carry out some scale with the flow back of the treatment fluid. When the viscosity of the fluid is increased or gelled, the treatment fluid can provide better coverage and carry suspended particles, including small pieces of scale.
- the treatment fluid can be a single fluid that dissolves calcium/magnesium/iron carbonate solids in a wellbore tubular at a controlled rate and under a wide range of conditions, especially over a broad range of pH and time.
- the invention can be advantageous because it can provide methods for treating wellbore tubulars for such purposes using treatment fluids that are non-acid containing and non-corrosive.
- the treatment methods according to the invention are expected to be effective for applications associated with: removal of carbonate scale from downhole wellbore tubulars or subsurface wellbore completion equipment, particularly where the use of strongly acidic fluids might be problematic, for example, in high-temperature formations due to reaction rates, or due to corrosion, etc.
- the new approach is a method for treating at least a portion of a downhole wellbore tubular or subsurface equipment, the method comprising the steps of: (A) determining the likelihood of the presence of scale in the downhole wellbore tubular or subsurface equipment; (B) forming or providing a treatment fluid comprising: (i) water; (ii) a chelating agent capable of forming a heterocyclic ring that contains a metal ion attached to at least two nonmetal ions; and (iii) a viscosity-increasing agent; and (C) introducing the treatment fluid into the wellbore tubular or subsurface equipment.
- Determining the likelihood of the presence of carbonate scale in the downhole wellbore tubular or subsurface equipment is an important step in the remediation process according to the invention.
- Scale in wellbore tubulars or subsurface completion equipment tends to occur as a thick layer on the inside wall of the tubular or completion equipment.
- the scale lowers the production rate from the wellbore by increasing the surface roughness of the inner wall of the tubular or equipment and reducing the cross-sectional flow area.
- the pressure required to push a fluid through the tubular area increases, flow decreases, and production decreases.
- scale damage is usually caused by temperature-activated autoscaling.
- incompatible mixing of different waters can occur when injection water contacts either natural formation water or completion brine. Scale formed in an injection well can decrease the effectiveness of a water-flood strategy.
- production analysis can indicate wellbore tubing scale, especially if a well suddenly demonstrates tubing constraints that were not present during early production.
- Determining the likelihood of the presence of carbonate scale can also be obtained by taking samples of downhole scale or X-ray evidence from core analysis.
- Gamma ray log interpretation often indicates barium sulfate scale because naturally occurring radioactive strontium tends to precipitate with this type of scale mineral.
- Downhole scale sensors and permanent monitoring applications are areas of active research.
- chemical modeling can be used to determine the likelihood of the presence of scaling based on tracking water analysis for mineral concentrations and other conditions, such as temperature, pressure, pH, and gas- phase compositions.
- the results of such techniques can be used to indicate the need for scale treatment of the downhole wellbore tubulars or subsurface equipment.
- the chelating agent in the treatment fluid can react with and dissolve calcium carbonate, magnesium carbonate, dolomite, iron carbonate, and similar materials of scale in the wellbore tubular, helping to re-open up the tubular, whereby hydrocarbon production through the tubular can be enhanced.
- CaCO 3 and CaMg(CO 3 ) 2 may precipitate from water as scale in wellbore tubulars.
- Typical scales are of calcium carbonate, calcium sulfate, barium sulfate, strontium sulfate, iron sulfide, iron oxides, iron carbonate, various silicates and phosphates and oxides, or any of a number of compounds insoluble or slightly soluble in water.
- the chelating agent can be helpful in removing calcium carbonate, magnesium carbonate, dolomite, iron carbonate, and similar materials of scale.
- to chelate means to combine a metal ion with a chemical compound to form a ring.
- the water further includes a water-soluble inorganic salt dissolved therein.
- the purpose of the inorganic salt can be, for example, to weight the water of the treatment fluid or to make the treatment fluid more compatible and less damaging to the subterranean formation.
- a source of at least a portion of the water and the inorganic salt can be selected from the group consisting of natural or synthetic brine or seawater.
- Inorganic salt or salts can also be mixed with the water of the treatment fluid to artificially make up or increase the inorganic salt content in the water.
- a water-soluble salt replacement can be utilized such as tetramethyl ammonium chloride (TMAC) and similar organic compounds.
- TMAC tetramethyl ammonium chloride
- the pH of the treatment fluid is equal to or greater than 2, which is above the pH of strong inorganic acids that have been used to help dissolve and remove carbonate materials from the formation.
- the pH of the treatment fluid is equal to or greater than 5, which is well above the pH of spent acid fluids used for the purpose of removing carbonate, where the pH of an acid fluid is typically less than about 3.5.
- the compositions of the present invention can be used to help dissolve and remove carbonate materials from the formation with less acidic compositions. In some applications, acidic compositions can be damaging to the well or hydrocarbon production.
- the pH of the treatment fluid is in the range of 6 - 12, which can be used to avoid or reduce the use of substantially acidic compositions in treating the formation. It is important to note, of course, that different chelating agents work better in certain pH ranges than other ranges. Some chelating agents can be effective in the higher pH ranges. One skilled in the art would also recognize the obvious advantage of using a non-acid fluid may reduce the rate of corrosion.
- the chelating agent is selected to be effective for chelating at least calcium ions. It is also highly desirable that the chelating agent is soluble in distilled water at standard temperature and pressure at a concentration of at least 0.2 mole-equivalent for calcium ions per liter of the distilled water. As a test for whether or not the chelating agent would be effective for use in the present invention, it is believed that a solution of the chelating agent at a concentration of 0.2 mole-equivalent for calcium ions per liter of the distilled water should be effective for chelating at least 0.1 mole calcium ions per liter. Preferably, the test solution is effective when adjusted to have a pH in the range of 5 - 6. More preferably, the test solution is effective when adjusted to have a pH in the range of 6 - 8. One skilled in the art would recognize that similar tests can be performed for other ions such as magnesium, iron, etc.
- the chelating agent is preferably at a concentration of at least 0.01% by weight of the water. More preferably, the chelating agent is at a concentration in the range of 1% to 80% by weight of the water.
- the viscosity-increasing agent would typically comprise a polymeric material.
- the polymeric material is preferably selected from the group consisting of: guar gum and its derivatives, cellulose derivatives, welan gum, xanthan biopolymer and its derivatives, diutan, and its derivatives, scleroglucan and its derivatives, succinoglycan biopolymer and its derivatives, and any combination of any of the foregoing in any proportion.
- Derivatives can include, for example, industrially manufactured chemical derivatives, bioengineered chemical derivatives, or naturally occurring derivatives produced by mutated organisms producing the polymer.
- a preferred polymer is of the nature taught in U.S. Patent Application Serial No. 20060014648, which is incorporated herein by reference in its entirety.
- the viscosity-increasing agent can advantageously comprise a viscoelastic surfactant.
- a viscoelastic surfactant may comprise any viscoelastic surfactant known in the art, any derivative thereof, or any combination thereof.
- the term "viscoelastic surfactant” refers to a surfactant that imparts or is capable of imparting viscoelastic behavior to a fluid due, at least in part, to the association of surfactant molecules to form viscosifying micelles.
- These viscoelastic surfactants may be cationic, anionic, nonionic, or amphoteric/zwitterionic in nature.
- the viscoelastic surfactants may comprise any number of different compounds, including methyl ester sulfonates (e.g., as described in U.S. Patent Application Numbers 1 1/058,660, 11/058,475, 1 1/058,612, and 11/058,611, filed February 15, 2005, each of which is assigned to Halliburton Energy Services, Inc., the relevant disclosures of which are incorporated herein by reference), hydrolyzed keratin (e.g., as described in United States Patent No.
- methyl ester sulfonates e.g., as described in U.S. Patent Application Numbers 1 1/058,660, 11/058,475, 1 1/058,612, and 11/058,611, filed February 15, 2005, each of which is assigned to Halliburton Energy Services, Inc., the relevant disclosures of which are incorporated herein by reference
- hydrolyzed keratin e.g., as described in United States Patent No.
- sulfosuccinates taurates, amine oxides, ethoxylated amides, alkoxylated fatty acids, alkoxylated alcohols (e.g., lauryl alcohol ethoxylate, ethoxylated nonyl phenol), ethoxylated fatty amines, ethoxylated alkyl amines (e.g., cocoalkylamine ethoxylate), betaines, modified betaines, alkylamidobetaines (e.g., cocoamidopropyl betaine), quaternary ammonium compounds (e.g., trimethyltallowammonium chloride, trimethylcocoammonium chloride), derivatives of any of the foregoing, and any combinations of any of the foregoing in any proportion.
- alkoxylated alcohols e.g., lauryl alcohol ethoxylate, ethoxylated nonyl phenol
- ethoxylated fatty amines
- Suitable viscoelastic surfactants may comprise mixtures of several different compounds, including but not limited to: mixtures of an ammonium salt of an alkyl ether sulfate, a cocoamidopropyl betaine surfactant, a cocoamidopropyl dimethylamine oxide surfactant, sodium chloride, and water; mixtures of an ammonium salt of an alkyl ether sulfate surfactant, a cocoamidopropyl hydroxysultaine surfactant, a cocoamidopropyl dimethylamine oxide surfactant, sodium chloride, and water; mixtures of an ethoxylated alcohol ether sulfate surfactant, an alkyl or alkene amidopropyl betaine surfactant, and an alkyl or alkene dimethylamine oxide surfactant; aqueous solutions of an alpha-olefinic sulfonate surfactant and a betaine surfactant; and any combination of the foregoing mixtures in any proportion
- Examples of commercially-available viscoelastic surfactants suitable for use in the present invention may include, but are not limited to, Mirataine BET-O 30TM (an oleamidopropyl betaine surfactant available from Rhodia Inc., Cranbury, New Jersey), Aromox APA-TTM (an amine oxide surfactant available from Akzo Nobel Chemicals, Chicago, Illinois), Ethoquad 0/12 PGTM (a fatty amine ethoxylate quat surfactant available from Akzo Nobel Chemicals, Chicago, Illinois), Ethomeen T/12TM (a fatty amine ethoxylate surfactant available from Akzo Nobel Chemicals, Chicago, Illinois), Ethomeen S/ 12TM (a fatty amine ethoxylate surfactant available from Akzo Nobel Chemicals, Chicago, Illinois), and Rewoteric AM TEGTM (a tallow dihydroxyethyl betaine amphoteric surfactant available from Degussa Corp., Parsippany, New Jersey).
- the viscosity-increasing agent is at a concentration in the treatment fluid that is at least sufficient to make the viscosity of the treatment fluid greater than water. More preferably, the viscosity-increasing agent is at a 5 concentration in the treatment fluid that is sufficient to make the viscosity of the treatment fluid greater than 5 cP when measured at 511 reciprocal seconds on a Fann 35 A model viscometer with a number 1 spring and bob.
- the viscosity-increasing agent is at a concentration in the treatment fluid that is sufficient to make the viscosity of the treatment fluid in the range of 10 cP to 100 cP when measured at 51 1 reciprocal seconds on a 10 Fann 35 A model viscometer with a number 1 spring and bob.
- the viscosity- increasing polymeric agent is at a concentration of at least 0.05% by weight of the water. More preferably, the viscosity-increasing agent is at a concentration in the range of 0.05% to 15 10% by weight of the water.
- the treatment fluid further 0 comprises a crosslinking agent to crosslink the polymeric material of the viscosity-increasing agent.
- a crosslinking agent to crosslink the polymeric material of the viscosity-increasing agent.
- the crosslinking agent is selected from the group consisting of: borate releasing compounds, a source of titanium ions, a source of zirconium ions, a source of antimony ions, a source of aluminum ions, a source of periodate ions, a source of permanganate ions, and any 5 combination thereof in any proportion.
- the crosslinking agent is at a concentration of at least 0.025% by weight of the water.
- the crosslinking agent is at a concentration in the range of 0.025% to about 1% by weight of the water.
- the treatment fluid for use in the methods according to the invention includes a crosslinking agent
- the treatment fluid preferably further comprises a breaker adapted to break the viscosity-increasing agent.
- the viscosity- increasing agent is polysaccharide based
- the breaker is selected to be effective for breaking a polysaccharide-based viscosity-increasing agent.
- the breaker can be, for example, an enzyme.
- the enzyme is selected to be effective for breaking starch.
- an enzyme breaker is at a concentration of at least 0.01 Ib per 1000 gal of the water. More preferably, the enzyme breaker is at a concentration in the range of 0.01 Ib to 40 Ib per 1000 gal of the water.
- enzymes are often used as liquid compositions and that the above mentioned values are for fully formulated dry enzyme breakers that typically contain a large percentage of fillers.
- a breaker is employed for the viscosity-increasing agent
- the breaker is at a concentration that is at least sufficient to substantially reduce the viscosity produced by the viscosity producing agent in the treatment fluid.
- a preferred embodiment of the method according to the invention includes the steps of allowing time for the breaker to break the viscosity of the treatment fluid and then flowing back the broken fluid from the wellbore.
- the breaker is preferably an oxidizer selected from the group consisting of: a persulfate; a perborate; a bromate; a periodate; a chlorate; a chlorite; a hypochlorite, an organic peroxide; and any combination thereof in any proportion.
- the breaker is more preferably selected from the group consisting of a lithium, sodium, potassium, or ammonium salt of any of the foregoing, and any combination thereof in any proportion.
- the oxidizing breaker for breaking a viscosity-increasing agent internal to the treatment fluid is preferably at a concentration of at least 0.01 Ib per 1000 gal of the water. More preferably, such a breaker is at a concentration in the range of 0.1 to 200 per
- the breaker be a delayed release breaker.
- One technique for making a delayed breaker is to coat or encapsulate the breaker to delay the release of the breaker into the water.
- Another technique is to generate the breaker in situ over time or upon a change in pH of the treatment fluid.
- the method further includes the step of: after introducing the treatment fluid into the wellbore, allowing the viscosity of the treatment fluid to break to a substantially lower viscosity fluid while down hole.
- the method further comprises the step of: after allowing the viscosity of the treatment fluid to break, flowing the fluid back from the well.
- the treatment fluid can further comprise a breaker to be carried by the treatment fluid into the wellbore for breaking a viscosity-increasing agent that is external of the treatment fluid.
- the breaker for the viscosity-increasing agent in the treatment fluid is preferably at a concentration in an external aqueous fluid that is at least sufficient to substantially break the viscosity of the treatment fluid.
- the breaker for a viscosity-increasing agent that is external to the treatment fluid can be the same or different than the breaker for the viscosity-increasing agent in the treatment fluid.
- the additional or different breaker for breaking a viscosity-increasing agent external to the treatment fluid is preferably at a concentration of at least 0.01 Ib per 1000 gal of the water. More preferably, the breaker is at a concentration in the range of 0.1 Ib to 200 Ib per 1000 gal of the water.
- the treatment fluid is allowed a sufficient time to attack the scale in the wellbore tubular.
- the treatment fluid is flowed back from the well without breaking the viscosity of the fluid.
- the purpose of the maintaining the viscosity of the treatment fluid during a step of flowing back of the treatment fluid is to help carry particles and pieces of the scale that may be loosened from the scale layers but not completely dissolved by the treatment fluid.
- the methods according to the invention can include foaming of the treatment fluid.
- the treatment fluid further comprises: an additive for foaming.
- the treatment fluid may be formed at a remote location and provided to the well site for the treatment method, or it can be formed locally at the well site.
- the treatment fluid preferably further comprises: a sufficient gas to form a foam.
- foam also refers to commingled fluids.
- the gas would be mixed with the other constituents of the treatment fluid at the well site to form a foamed or co-mingled fluid.
- the gas is selected from the group consisting of: air, CO 2 , nitrogen, and any combination thereof in any proportion. In applications of the method utilizing a gas, typically, the gas is at a concentration in the range of 5% to 95% by volume of the water.
- the step of introducing the treatment fluid into the wellbore further comprises: introducing the treatment fluid at a rate and pressure below the fracture gradient of the subterranean formation.
- the treatment fluid is applied such that the treatment fluid is introduced such that the proppant pack of a previously generated fracture or gravel pack is treated.
- the permeability of the matrix of the surrounding formation would be expected to be relatively high.
- the treatment fluid is applied such that the portion of the subterranean formation is a portion surrounding the wellbore, and wherein the treatment fluid is introduced such that the portion surrounding the wellbore is expected to be saturated to a depth of at least 1 foot. More preferably, the treatment fluid is applied such that the portion surrounding the wellbore is expected to be saturated to a depth in the range of 1 foot to 3 feet.
- desired or expected depth of penetration into the surrounding matrix of the formation will not necessarily be perfectly uniform.
- parameters for designing a treatment for a desired or expected depth of penetration are well known in the art, including, for example, the length of the wellbore to be treated and the volume of treatment fluid injected into the wellbore.
- a deeper penetration may be desired or obtained in formations with higher permeability.
- the permeability of the matrix of the surrounding formation would be expected to be relatively low.
- the portion of the subterranean formation is an area surrounding a fracture extending into the formation, and the treatment fluid is introduced such that the surrounding area is expected to be saturated to a depth of at least 0.1 inches.
- the treatment fluid is introduced into the wellbore under conditions such that the area surrounding the fracture is expected to be saturated to a depth in the range of 0.1 inches to 2 inches.
- a deeper penetration may be desired or obtained in formations with higher permeability.
- the portion of the subterranean formation is a perforation tunnel
- the treatment fluid is introduced such that the perforation tunnel and the surrounding area is expected to be saturated to a depth of at least 0.1 inches. More preferably, the treatment fluid is introduced into the wellbore under conditions such that the area surrounding the perforation tunnel is expected to be saturated to a depth in the range of 0.1 inches to 2 inches.
- the treatment fluid is introduced into the wellbore under conditions such that the area surrounding the perforation tunnel is expected to be saturated to a depth in the range of 0.1 inches to 2 inches.
- the methods further comprise the step of: after the step of introducing the treatment fluid, introducing a non-viscosified treatment fluid into the wellbore, wherein the non-viscosified treatment fluid comprises: water and a chelating agent, without any substantial concentration of any viscosity-increasing agent.
- the viscosified treatment fluid is capable of moving into zones of the subterranean formation that have relatively higher permeability, thereby diverting the non-viscosified treatment fluid into zones of the subterranean formation that have relatively lower permeability.
- the injection pressure is preferably maintained from the step of introducing the treatment fluid to the step of introducing the non-viscosified treatment fluid.
- the methods further comprise the step of: applying an afterflush fluid to the portion of the subterranean formation or wellbore tubular.
- the afterflush fluid can comprise: water, a gas, a brine, a hydrocarbon, or a mixture thereof.
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Inorganic Chemistry (AREA)
- Detergent Compositions (AREA)
- Preventing Corrosion Or Incrustation Of Metals (AREA)
- Edible Oils And Fats (AREA)
- Physical Or Chemical Processes And Apparatus (AREA)
- Consolidation Of Soil By Introduction Of Solidifying Substances Into Soil (AREA)
- Lubricants (AREA)
Abstract
Description
Claims
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CA2685607A CA2685607C (en) | 2007-05-10 | 2008-05-09 | Methods for stimulating oil or gas production |
MX2009012110A MX2009012110A (en) | 2007-05-10 | 2008-05-09 | Methods for stimulating oil or gas production. |
BRPI0811024A BRPI0811024B1 (en) | 2007-05-10 | 2008-05-09 | method for treating a downhole drilling tubular or subsurface completion equipment |
AU2008249777A AU2008249777B2 (en) | 2007-05-10 | 2008-05-09 | Methods for stimulating oil or gas production |
EP08750554.1A EP2158289B1 (en) | 2007-05-10 | 2008-05-09 | Methods for stimulating oil or gas production |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/801,200 | 2007-05-10 | ||
US11/801,209 US20080277112A1 (en) | 2007-05-10 | 2007-05-10 | Methods for stimulating oil or gas production using a viscosified aqueous fluid with a chelating agent to remove calcium carbonate and similar materials from the matrix of a formation or a proppant pack |
US11/801,209 | 2007-05-10 | ||
US11/801,200 US8071511B2 (en) | 2007-05-10 | 2007-05-10 | Methods for stimulating oil or gas production using a viscosified aqueous fluid with a chelating agent to remove scale from wellbore tubulars or subsurface equipment |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2008139164A1 true WO2008139164A1 (en) | 2008-11-20 |
Family
ID=39684367
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/GB2008/001615 WO2008139164A1 (en) | 2007-05-10 | 2008-05-09 | Methods for stimulating oil or gas production |
Country Status (6)
Country | Link |
---|---|
EP (2) | EP2548934A1 (en) |
AU (1) | AU2008249777B2 (en) |
BR (1) | BRPI0811024B1 (en) |
CA (1) | CA2685607C (en) |
MX (1) | MX2009012110A (en) |
WO (1) | WO2008139164A1 (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2012113738A1 (en) * | 2011-02-22 | 2012-08-30 | Akzo Nobel Chemicals International B.V. | Chelating agent precursors, fluids containing them, and their use |
US9150780B2 (en) | 2010-12-17 | 2015-10-06 | Akzo Nobel Chemicals International B.V. | Environmentally friendly stimulation fluids, processes to create wormholes in carbonate reservoirs, and processes to remove wellbore damage in carbonate reservoirs |
US9803134B2 (en) | 2008-01-09 | 2017-10-31 | Akzo Nobel Chemicals International B.V. | Acidic aqueous solution containing a chelating agent and the use thereof |
US10301534B2 (en) | 2010-12-17 | 2019-05-28 | Akzo Nobel Chemicals International B.V. | Treatment of illitic formations using a chelating agent |
RU2758371C1 (en) * | 2020-08-17 | 2021-10-28 | Акционерное Общество Малое Инновационное Предприятие Губкинского Университета "Химеко-Сервис" (АО МИПГУ "Химеко-Сервис") | Composition for removing barium and calcium sulphate scaling and method for application thereof |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2015147852A1 (en) | 2014-03-28 | 2015-10-01 | Halliburton Energy Services, Inc. | Treatment fluids for reducing subterranean formation damage |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4353805A (en) * | 1978-12-01 | 1982-10-12 | Ceca S.A. | Enhanced oil recovery |
EP0073599A1 (en) * | 1981-08-20 | 1983-03-09 | Pfizer Inc. | Polyvalent metal ion chelating agents for xanthan solutions |
EP1188772A2 (en) * | 2000-09-15 | 2002-03-20 | Noviant Oy | Ligand-modified cellulose products |
US20040011527A1 (en) * | 2000-08-07 | 2004-01-22 | Jones Timothy Gareth John | Scale dissolver fluid |
WO2004090282A1 (en) * | 2003-04-11 | 2004-10-21 | Halliburton Energy Services, Inc. | Xanthan gels in brines and methods of using such xanthan gels in subterranean formations |
WO2005121273A1 (en) * | 2004-06-07 | 2005-12-22 | Baker Hughes Incorporated | Metal-mediated viscosity reduction of fluids gelled with viscoelastic surfactants |
Family Cites Families (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5783082A (en) | 1995-11-03 | 1998-07-21 | University Of North Carolina | Cleaning process using carbon dioxide as a solvent and employing molecularly engineered surfactants |
EP0786283B1 (en) | 1996-01-24 | 2003-01-02 | Mitsubishi Materials Corporation | NOX-cleaning paving block |
CA2182055C (en) | 1996-07-25 | 1999-05-11 | Julien Martineau | Concrete form system, ties therefor, and method of using the system and ties |
US5897699A (en) | 1997-07-23 | 1999-04-27 | Halliburton Energy Services, Inc. | Foamed well cement compositions, additives and methods |
GB2338254B (en) * | 1998-06-12 | 2002-10-16 | Sofitech Nv | Well completion clean-up fluids and method for cleaning up drilling and completion filtercakes |
US6063738A (en) | 1999-04-19 | 2000-05-16 | Halliburton Energy Services, Inc. | Foamed well cement slurries, additives and methods |
CA2437285C (en) * | 2000-08-07 | 2009-11-03 | Schlumberger Canada Limited | Viscoelastic wellbore treatment fluids comprising oligomeric surfactants |
US6367550B1 (en) | 2000-10-25 | 2002-04-09 | Halliburton Energy Service, Inc. | Foamed well cement slurries, additives and methods |
US20060014648A1 (en) | 2004-07-13 | 2006-01-19 | Milson Shane L | Brine-based viscosified treatment fluids and associated methods |
US7621334B2 (en) * | 2005-04-29 | 2009-11-24 | Halliburton Energy Services, Inc. | Acidic treatment fluids comprising scleroglucan and/or diutan and associated methods |
-
2008
- 2008-05-09 AU AU2008249777A patent/AU2008249777B2/en active Active
- 2008-05-09 EP EP12188467A patent/EP2548934A1/en not_active Withdrawn
- 2008-05-09 BR BRPI0811024A patent/BRPI0811024B1/en not_active IP Right Cessation
- 2008-05-09 EP EP08750554.1A patent/EP2158289B1/en not_active Not-in-force
- 2008-05-09 WO PCT/GB2008/001615 patent/WO2008139164A1/en active Application Filing
- 2008-05-09 MX MX2009012110A patent/MX2009012110A/en active IP Right Grant
- 2008-05-09 CA CA2685607A patent/CA2685607C/en not_active Expired - Fee Related
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4353805A (en) * | 1978-12-01 | 1982-10-12 | Ceca S.A. | Enhanced oil recovery |
EP0073599A1 (en) * | 1981-08-20 | 1983-03-09 | Pfizer Inc. | Polyvalent metal ion chelating agents for xanthan solutions |
US20040011527A1 (en) * | 2000-08-07 | 2004-01-22 | Jones Timothy Gareth John | Scale dissolver fluid |
EP1188772A2 (en) * | 2000-09-15 | 2002-03-20 | Noviant Oy | Ligand-modified cellulose products |
WO2004090282A1 (en) * | 2003-04-11 | 2004-10-21 | Halliburton Energy Services, Inc. | Xanthan gels in brines and methods of using such xanthan gels in subterranean formations |
WO2005121273A1 (en) * | 2004-06-07 | 2005-12-22 | Baker Hughes Incorporated | Metal-mediated viscosity reduction of fluids gelled with viscoelastic surfactants |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9803134B2 (en) | 2008-01-09 | 2017-10-31 | Akzo Nobel Chemicals International B.V. | Acidic aqueous solution containing a chelating agent and the use thereof |
US9150780B2 (en) | 2010-12-17 | 2015-10-06 | Akzo Nobel Chemicals International B.V. | Environmentally friendly stimulation fluids, processes to create wormholes in carbonate reservoirs, and processes to remove wellbore damage in carbonate reservoirs |
US10294412B2 (en) | 2010-12-17 | 2019-05-21 | Akzo Nobel Chemicals International B.V. | Environmentally friendly stimulation fluids, processes to create wormholes in carbonate reservoirs, and processes to remove wellbore damage in carbonate reservoirs |
US10301534B2 (en) | 2010-12-17 | 2019-05-28 | Akzo Nobel Chemicals International B.V. | Treatment of illitic formations using a chelating agent |
WO2012113738A1 (en) * | 2011-02-22 | 2012-08-30 | Akzo Nobel Chemicals International B.V. | Chelating agent precursors, fluids containing them, and their use |
US9556378B2 (en) | 2011-02-22 | 2017-01-31 | Akzo Nobel Chemicals International B.V. | Chelating agent precursors, fluids containing them, and their use |
RU2758371C1 (en) * | 2020-08-17 | 2021-10-28 | Акционерное Общество Малое Инновационное Предприятие Губкинского Университета "Химеко-Сервис" (АО МИПГУ "Химеко-Сервис") | Composition for removing barium and calcium sulphate scaling and method for application thereof |
Also Published As
Publication number | Publication date |
---|---|
BRPI0811024B1 (en) | 2018-05-08 |
CA2685607A1 (en) | 2008-11-20 |
BRPI0811024A2 (en) | 2014-12-09 |
MX2009012110A (en) | 2009-11-25 |
EP2158289A1 (en) | 2010-03-03 |
EP2158289B1 (en) | 2016-12-07 |
AU2008249777B2 (en) | 2013-03-14 |
CA2685607C (en) | 2012-09-25 |
EP2548934A1 (en) | 2013-01-23 |
AU2008249777A1 (en) | 2008-11-20 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US8071511B2 (en) | Methods for stimulating oil or gas production using a viscosified aqueous fluid with a chelating agent to remove scale from wellbore tubulars or subsurface equipment | |
US20130000901A1 (en) | Methods for Stimulating Oil or Gas Production Using a Viscosified Aqueous Fluid with a Chelating Agent to Remove Calcium Carbonate and Similar Materials from the Matrix of a Formation or a Proppant Pack | |
US8567503B2 (en) | Composition and method relating to the prevention and remediation of surfactant gel damage | |
US9074120B2 (en) | Composition and method relating to the prevention and remediation of surfactant gel damage | |
EP2113547B1 (en) | Methods comprising viscosified fluids for remediating subterranean damage background | |
US8881823B2 (en) | Environmentally friendly low temperature breaker systems and related methods | |
CA2491529C (en) | Compositions and methods for treating a subterranean formation | |
CA2587430C (en) | Composition and method for treating a subterranean formation | |
CA2677462C (en) | Treatment fluids comprising diutan and associated methods | |
CA2676296C (en) | Methods for reducing the viscosity of treatment fluids comprising diutan | |
US20140124205A1 (en) | Process to fracture a subterranean formation using a chelating agent | |
AU2008249777B2 (en) | Methods for stimulating oil or gas production | |
EP2185666A1 (en) | Treatment fluids comprising clarified xanthan and associated methods | |
Alhamad et al. | Organic acids for stimulation purposes: a review | |
EP3101086A1 (en) | Process to treat closed fractures in a subterranean formation using an iminodiacetic acid or salt thereof |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 08750554 Country of ref document: EP Kind code of ref document: A1 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2008249777 Country of ref document: AU |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2685607 Country of ref document: CA |
|
ENP | Entry into the national phase |
Ref document number: 2008249777 Country of ref document: AU Date of ref document: 20080509 Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: MX/A/2009/012110 Country of ref document: MX |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
REEP | Request for entry into the european phase |
Ref document number: 2008750554 Country of ref document: EP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2008750554 Country of ref document: EP |
|
ENP | Entry into the national phase |
Ref document number: PI0811024 Country of ref document: BR Kind code of ref document: A2 Effective date: 20091027 |