RU2487908C2 - Additional surface-active compositions and methods for preparation and use thereof - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: surface-active composition, containing: a first surface-active subsystem containing a fluorinated PAD, a second PAD containing an organosilicon PAD, and optionally a solvent subsystem, where the composition is capable of foaming a fluid medium, which contains spectroscopically analysed crude oil and/or a condensate present in a producing formation. A drilling mud contains said surface-active composition. A completion fluid composition contains said surface-active composition. A hydraulic fracturing composition contains said surface-active composition. A formation stimulation composition contains said surface-active composition. A method of foaming a fluid medium containing oil and/or condensate involves analysing crude oil and/or condensate, preparing said surface-active composition, adding to well fluid and adding a foaming gas.

EFFECT: high stability of compositions over time and at high temperatures.

20 cl, 2 tbl, 1 dwg

Description

BACKGROUND OF THE INVENTION

1. Field of invention

Embodiments of the present invention relate to additional surface active systems for use in drilling operations and to methods for their manufacture and use.

More specifically, embodiments of the present invention relate to additional surface active systems for use in drilling operations and methods for their manufacture and use, the systems including a surface active subsystem and an optional solvent subsystem, where the surface active subsystem includes a fluorinated surfactant and an organosilicon surfactant, the systems can be tuned to a specific reservoir to achieve The desired height of the foam and the half-life of the foam in drilling, production and stimulation operations.

2. Description of the Related Art

There are few compatible surfactants that have the desired properties of foams for multi-purpose mining, drilling, and the extraction of crude oil and especially condensate.

There are two categories of oil-based or so-called hydrocarbon surfactants: surfactants based on organosilicon compounds and surfactants based on fluorocarbon compounds. While the use of fluorocarbon surfactants is limited to mining operations, including hydraulic fracturing and possibly condensate recovery, as described in US Patent Nos. 4,796,702; 4836281 and 4404112, organosilicon surfactants, as shown by Falana and others in US patent publication No. 2010-0000795 A1, suitable for compositions used in drilling under reduced hydrostatic pressure in the wellbore. The use of surfactants in the recovery of condensates is still characterized by unexplained inconsistencies in compatibility or lack thereof in the transition from one condensate to another. Currently, in the United States, fluorocarbon surfactants are known to be environmentally harmful, while surfactants based on organosilicon compounds are known to be produced in solvents that are suspected of causing cancer or harm. environment, for example, alkylbenzenes. In addition, a mixture of polyglycosides and amphoteric surfactants was used to recover less than 100% of the condensates, as described in US Patent Publication No. 2007/0181307 A1.

Thus, there is a need to develop surface-active systems for use in drilling, production and stimulation operations that can be reconfigured to a productive formation so that the desired height and half-life of the foam can be provided.

SUMMARY OF THE INVENTION

Embodiments of the present invention provide surfactant compositions comprising from 0 wt.% To 100 wt.% Of the first surfactant subsystem, from 100 wt.% To 0 wt.% Of the second surfactant subsystem, and from 0 wt.% To 100 wt.% solvent subsystem based on the mass percentage of surface-active subsystems, where the composition is adapted for foaming a fluid, including spectroscopically analyzed crude oil and / or condensate present in the reservoir.

Embodiments of the present invention provide drilling fluid compositions comprising from 0 wt.% To 100 wt.% Of the first surfactant subsystem, from 100 wt.% To 0 wt.% Of the second surfactant subsystem, and from 0 wt.% To 100 wt. .% solvent subsystem based on the mass percentage of surface-active subsystems, where the systems are adapted for foaming drilling fluid compositions including spectroscopically analyzed crude oil and / or condensate present in the reservoir.

Embodiments of the present invention provide a well completion solution composition comprising a surfactant system comprising from 0 wt.% To 100 wt.% Of the first surfactant subsystem, from 100 wt.% To 0 wt.% Of the second surfactant subsystem, and from 0 wt.% to 100 wt.% of the solvent subsystem based on the mass percentage of surface-active subsystems, where the systems are adapted for foaming the composition of the well completion solution, including a spectroscopically analyzed crude oil ft and / or condensate present in the reservoir.

Embodiments of the present invention provide a hydraulic fracturing solution composition comprising a surfactant system comprising from 0 wt.% To 100 wt.% Of the first surfactant subsystem, from 100 wt.% To 0 wt.% Of the second surfactant subsystem and from 0 wt.% to 100 wt.% of the solvent subsystem based on the mass percentage of surface-active subsystems, where the system is adapted for foaming fluid fracturing compositions, including spectroscopically ana iziruemuyu crude oil and / or condensate present in the reservoir.

Embodiments of the present invention provide a composition solution for stimulating a formation containing a surfactant system comprising from 0 wt.% To 100 wt.% Of the first surfactant subsystem, from 100 wt.% To 0 wt.% Of the second surfactant subsystem and from 0 wt.% to 100 wt.% of the solvent subsystem based on the mass percentage of surface-active subsystems, where the system is adapted for foaming solution compositions for stimulating the formation, including a spectroscopically analyzed crude oil and / or condensate present in the reservoir.

Embodiments of the present invention provide methods for foaming a fluid including crude oil and / or condensate, including analyzing crude oil and / or condensate from a reservoir. The methods also include preparing a surfactant system comprising from 0 wt.% To 100 wt.% Of the first surfactant subsystem, from 100 wt.% To 0 wt.% Of the second surfactant subsystem, and from 0 wt.% To 100 wt. .% solvent subsystem based on the mass percentage of surface-active subsystems, where the system is adapted for foaming a fluid, including the analyzed crude oil and / or condensate. The methods also include adding an effective amount of a surfactant system to the well fluid, where the effective amount is sufficient to form a stable foam when gas is added. The methods also include adding a foaming amount of gas to the wellbore fluid sufficient to turn the fluid into a stable foam.

For drilling fluids, embodiments of the methods of the present invention further include injecting the drilling fluid into the borehole while drilling through the drill bit, where the fluid includes a surfactant system comprising from 0 wt.% To 100 wt.% Of the first surfactant subsystem, from 100 wt.% to 0 wt.% of the second surface-active subsystem and from 0 wt.% to 100 wt.% of the solvent subsystem based on the mass percentage of surface-active subsystems, where the system is adapted for the formation of a fluid, including the analyzed crude oil and / or condensate, and the introduction of an effective amount of gas for foaming the drilling fluid to obtain a stable foam of the drilling fluid.

For hydraulic fracturing solutions, embodiments of the methods of the present invention further include injecting the hydraulic fracturing solution into the producing formation under conditions of formation of cracks in the formation in the presence or absence of a proppant, where the fluid includes a surfactant system comprising from 0 wt. % to 100 wt.% of the first surface-active subsystem, from 100 wt.% to 0 wt.% of the second surface-active subsystem and from 0 wt.% to 100 wt.% of the subsystem On the basis of the mass percentage of surface-active subsystems, and where the system is adapted for foaming a fluid including the analyzed crude oil and / or condensate.

For lifting solutions, embodiments of the methods of the present invention further include injecting a foaming effective amount of gas and the lifting solution into the finished and productive formation to produce a stable foam of the lifting solution, reducing the weight of the column and improving production, where the lifting solution includes an effective amount of a surface-active system comprising 0 wt.% To 100 wt.% Of the first surface-active subsystem, from 100 wt.% To 0 wt.% Of the second surface-active subsystem and from 0 m p.% to 100 wt.% solvent based subsystem mass percentage of surface-active subsystems, wherein the system is adapted for foaming fluid consisting analyzed crude oil and / or condensate.

For formation stimulation solutions, embodiments of the methods of the present invention further include injecting a foaming effective amount of gas and formation stimulation solution into a finished and productive formation to produce stable foam under conditions of heat and pressure sufficient to introduce foam into the formation to improve production, where the lifting solution includes an effective amount of a surfactant system comprising from 0 wt.% to 100 wt.% the first surfactant subsystem, from 100 wt.% up to 0 wt.% of the second surface-active subsystem and from 0 wt.% to 100 wt.% of the solvent subsystem based on the mass percentage of surface-active subsystems, where the system is adapted for foaming a fluid, including the analyzed crude oil and / or condensate.

Embodiments of the methods of the present invention include a method for drilling oil and / or gas wells, including the steps of creating an oil-based drilling fluid foam according to the present invention. The method also includes the step of drilling oil and / or gas wells using a drilling fluid. The method also includes adding or introducing a sufficient amount of nitrogen-containing gas to obtain a stable foam so that the pressure of the fluid is lower or practically equal to the pressure of the fluid of the formation in which the drilling is carried out.

Brief Description of the Drawings

The present invention can be better understood by referring to the following detailed description together with the accompanying illustrative drawings, in which like elements are denoted by the same numbers:

FIG. 1 represents the superposition of infrared spectra with Fourier transform of aromatic and non-aromatic condensates relative to red diesel fuel.

Definitions of Terms Used in the Invention

The following definitions are provided to assist those skilled in the art in understanding the detailed description of the present invention.

The term "hydraulic fracturing" means the process and methods of fracturing a geological formation, that is, rock around a well, by pumping a fluid at very high pressures to increase the productivity of a hydrocarbon source. Otherwise, the methods of hydraulic fracturing according to the present invention use traditional technologies known in the art.

The term "surfactant" means a soluble or partially soluble compound that reduces the surface tension of liquids or reduces the interfacial tension between two liquids or liquid and solid phases due to its accumulation and orientation on these interfaces.

The term “drilling fluids” means any fluid that is used during drilling operations, including oil and / or gas wells, geothermal wells, water wells, or other similar wells.

The term "completion fluid" means any fluid that is used in completion operations of an oil and / or gas well.

The term "production fluid" means any fluid that is used in the operational operations of an oil and / or gas well.

A reduced and / or controlled pressure drilling fluid means a drilling fluid having a circulating hydrostatic density (pressure) below or at a formation density (pressure) level. For example, if a known formation at an actual vertical depth (FHG) of 10,000 feet (3,048 m) has a hydrostatic pressure of 5,000 psi. inch or 9.6 lb-meters per gallon (3.45 • 10 ⁷ Pa), the reduced pressure drilling fluid would have a hydrostatic pressure not exceeding 9.6 lb-meters per gallon (3.45 • 10 ⁷ Pa). Most low and / or controlled pressure drilling fluids include at least a density reducing additive. Other additives include mainly a corrosion inhibitor, an acidity regulator, and a scale inhibitor.

The term “foaming” means a composition that, when mixed with gas, forms a stable foam.

The term “GTG” means the number of gallons per thousand gallons.

The term “phtg” means the number of pounds per thousand gallons.

DETAILED DESCRIPTION OF THE INVENTION

The inventors of the present invention have discovered that it is possible to formulate surfactant systems for use in downhole operations affecting reservoirs, where the systems are rebuilt to obtain the desired foam heights and half-lives according to the nature of the fluids present in the reservoir. The systems include a fluorinated surfactant subsystem, an organosilicon surfactant subsystem, and an optional solvent subsystem.

The inventors of the present invention examined surface activity to determine why surface activity varies with the nature of the fluid in the reservoir, for example, the differences between crude oil, condensate and / or other similar fluids present in the reservoir. By analyzing a number of condensates, evidence has been obtained that these fluids are characteristic different. Condensates vary in their constituents, including aliphatic, aromatic, naphthalene, unsaturated compounds, other fluid components, or mixtures and combinations thereof.

The inventors have also noted that most fluorinated surfactants, including polymeric fluorinated surfactants, can be environmentally unstable or non-hazardous components in which these surfactants can then be used to selectively foame a fluid containing 100 % condensate. In addition, it has been shown that organosilicon surfactants also foaming similar fluids.

The inventors of the present invention have found that mixtures of surfactants of these two classes can constitute environmentally sound systems in which mixtures of two surfactants exhibit synergistic properties.

The first surfactant subsystem includes one surfactant fluoroaliphatic polymer ester (FAPE) or a plurality of surfactant fluoroaliphatic polymer esters, hereinafter indicated by the abbreviation FFS. In certain embodiments, a surface active fluoroaliphatic polymer ester (FAPE) is described in international patent applications WO 2008/089391 A1 and WO 2008/089386 A2 and is available from 3-M Innovative Properties Company (St. Paul, Minnesota, USA). In certain embodiments, pure FAPE surface active polymers can be used in the surface active systems of the present invention. In certain embodiments, a surface active fluoroaliphatic polymer ester (FAPE) may include a nonionic polymer surfactant. In some embodiments, the non-ionic polymeric surfactant comprises fluorinated repeating units containing 4 (in some embodiments, 3, 2, or even 1) perfluorinated carbon atoms. In some embodiments, non-ionic polymeric surfactants useful in the practice of the present invention include at least one divalent unit represented by formula I:

In some embodiments, non-ionic polymeric surfactants useful in the practice of the present invention include at least one divalent unit represented by formula Ia:

In formula I or Ia, Rf represents a perfluoroalkyl group containing from 3 to 4 carbon atoms (for example, perfluoro-n-butyl, perfluoroisobutyl, perfluoro-sec-butyl, perfluoro-tert-butyl, perfluoro-n-propyl, or perfluoroisopropyl) . In some embodiments of formula I or Ia, Rf is perfluoro-n-butyl. In the formula I or Ia, R represents a hydrogen atom or an alkyl group containing from 1 to 4 carbon atoms (for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or sec-butyl). In some embodiments of Formula I or Ia, R is methyl or ethyl.

In the formula I or Ia, n is an integer that takes values from 2 to 11 (i.e., 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11). In some embodiments, non-ionic polymeric surfactants useful in the practice of the present invention comprise at least one divalent unit represented by formula Ib:

In some embodiments, non-ionic polymeric surfactants useful in the practice of the present invention include repeating units having suspended alkyl groups containing from 14 to 24 (in some embodiments, from 16 to 24 or even from 18 to 22) carbon atoms . In some embodiments, non-ionic polymeric surfactants useful in the practice of the present invention include at least one divalent unit represented by formula II:

R ² represents a hydrogen atom or an alkyl group containing from 1 to 4 carbon atoms (for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or sec-butyl). In some embodiments of Formula II, R ² represents a hydrogen atom. In some embodiments of Formula II, R represents a methyl group.

R ¹ represents an alkyl group containing from 16 to 24 (in some embodiments, from 18 to 22) carbon atoms.

In some embodiments, non-ionic polymeric surfactants comprising at least one divalent unit represented by Formula II, wherein R ¹ is an alkyl group containing from 16 to 24 (or even from 18 to 22) carbon atoms, provides unexpectedly long-lived foam more than nonionic polymeric surfactants comprising at least one divalent unit represented by formula II, wherein R ¹ represents an alkyl group having less than 14 atoms carbon.

In some embodiments, non-ionic polymeric surfactants useful in the practice of the present invention include at least one divalent unit represented by formula I in an amount of from 45 to 75 (in some embodiments, from 50 to 70, or even from 55 to 65) wt.% Based on the total weight of the nonionic polymer surfactant.

In some embodiments, non-ionic polymeric surfactants useful in the practice of the present invention include at least one divalent unit represented by formula Ia in an amount of from 30 to 65 (in some embodiments, from 35 to 60, or even from 45 to 55) wt.% Based on the total weight of the nonionic polymer surfactant.

In some embodiments, non-ionic polymeric surfactants useful in the practice of the present invention include at least one divalent unit represented by Formula II in an amount of from 25 to 55 (in some embodiments, from 30 to 50, or even from 35 to 45) wt.% Or in an amount of from 35 to 70 (in some embodiments, from 40 to 65, or even from 45 to 55) wt.% Based on the total weight of the nonionic polymer surfactant.

In some embodiments of the non-ionic polymeric surfactants useful in the present invention, divalent groups independently represented by at least one of formulas I or Ia and divalent groups independently represented by formula II are randomly copolymerized.

Non-ionic polymeric surfactants useful in the practice of the present invention can be obtained, for example, by copolymerizing a mixture containing at least the first and second monomers, typically in the presence of a chain growth agent and an initiator. The term "copolymerization" means the formation of a polymer or oligomer, which includes at least one identifiable structural element belonging to each of the first and second monomers. Typically, the resulting polymer or oligomer has a molecular weight and composition distribution.

In some embodiments, the first monomer is at least one of the fluorinated free radical polymerizable monomers represented by formula III, IIIa, or IIIb:

,

,

in which Rf, R and n coincide with the radicals defined above for units of formulas I and Ia.

In some embodiments, the second monomer is an aliphatic free-radical polymerizable monomer represented by formula IV:

,

,

in which R ¹ and R ² coincide with the radicals defined above for the divalent unit of formula II.

In some embodiments, non-ionic polymeric surfactants useful for practical implementation and / or obtained in the framework of the present invention have a weight average molecular weight of at least 45,000 (in some embodiments, at least 50,000, 55,000, 60,000, 65,000, 70,000, 75,000, 80,000, 85,000, 90,000, 95,000, 100,000, 105,000, 110,000, 115,000, 120,000, 125,000, 130,000, 135,000, or even at least 140,000) g / mol. In some embodiments, non-ionic polymeric surfactants useful in the practice of the present invention have a weight average molecular weight of up to 250,000 (in some embodiments, up to 245,000, 240,000, 235,000, 230,000, 225,000, 220,000, 215,000, 210,000, 205,000, 200,000, 195000, 190000, 185000, 180000, 175000, 170000, 165000 or even up to 160,000) g / mol.

The second surfactant subsystem includes an organosilicon surfactant or a plurality of organosilicon surfactants, hereinafter indicated by the abbreviation FSS. In a specific embodiment, the second surfactant subsystem includes an organosilicon surfactant sold under the trade name OleoFoam C ™ (consisting of a foaming agent, thickener, initiator and antifoam agent), which is supplied by Weatherford, including a product from Dow Corning. Unlike the FAPE surfactants of the first surfactant subsystem, the second surfactant subsystem was used in foaming systems for drilling, as described in US patent publication No. 2010/0000795.

The second surface-active subsystem may include crude oil, a foaming agent and a hydrocarbon-soluble polymer, including a polymer of styrene monomer and diene monomer. Suitable hydrocarbon basic fluids include, without limitation, synthetic hydrocarbon fluids, petroleum-based hydrocarbon fluids, natural hydrocarbon (non-aqueous) fluids, or other similar hydrocarbons, or mixtures or combinations thereof. Illustrative examples of these hydrocarbon fluids include, but are not limited to, poly-α-olefins, polybutenes, polyol esters, biodiesel, low molecular weight fatty acid esters from plant or vegetable oil fractions, alcohol esters, including Exxate from Exxon Chemicals , vegetable oils, animal oils or esters, other essential oils, diesel, low or high sulfur diesel, kerosene, jet fuel, petroleum jelly, mineral oils, heavy flashpoint kerosene, hydrogenated oil, including PetroCanada HT-40N or IA-35 or similar oils manufactured by Shell Oil Company, internal double bond olefins containing about 12 to 20 carbon atoms, linear α- olefins containing from about 14 to 20 carbon atoms, poly-α-olefins containing from about 12 to about 20 carbon atoms, isomerized α-olefins (IAO) containing from about 12 to about 20 carbon atoms, Naptha and Linpar paraffins VM&P firms containing from 13 to about 16 carbon atoms, HF-1000, which is manufactured by Sasol (USA), and mixtures or combinations thereof.

Suitable polymers include, but are not limited to, a polymer comprising at least one aromatic olefin monomer and at least one diene monomer. The polymers may include random polymers, block copolymers, grafted copolymers, star polymers or other multi-branch polymers that include one or more aromatic olefin monomers and / or one or more diene monomers, or mixtures or combinations thereof. The term "polymer" as used in the present description means homopolymers, copolymers, polymers comprising three or more monomers (olefin monomers and / or diene monomers), polymers including grafted oligomeric or polymeric fragments, which may include monomers of the same or different composition, branches leaving the center of the polymer or forming a star structure of the reagent, including trivalent and tetravalent binding agents or divinylbenzene moieties and the like, and homopolymers having different tactics and and microstructure. Illustrative examples of aromatic olefin monomers are styrene, α-methylstyrene, α-trifluoromethylstyrene, fluorinated styrenes in which fluorine atoms occupy positions in the ring or in the ethylene group, chlorinated styrenes in which chlorine atoms occupy positions in the ring or in the ethylene group, alkylated styrenes in which alkyl groups occupy positions in the ring or in the ethylene group, vinyl pyridine, alkylated vinyl pyridines in which alkyl groups occupy positions in the ring or in ethylene to the alkyl group, fluorinated vinyl pyridines in which fluorine atoms occupy positions in the ring or in the ethylene group, chlorinated vinyl pyridines in which chlorine atoms occupy positions in the ring or in the ethylene group, or mixtures or combinations thereof. Illustrative examples of diene monomers include, but are not limited to, butadiene (B or BD), isoprene (2-methylbutadiene) (I), 2,3-dimethylbutadiene, 1,3-pentadiene, 1,3-hexadiene, or other similar 1,3- diene monomers, or mixtures or combinations thereof. Illustrative examples of polymers include, without limitation, styrene-isoprene copolymers (statistical or block copolymers), diblock copolymers (SI), triblock copolymers (SIS or ISI), multiblock copolymers (ISISIS, SISISI, etc.), styrene-butadiene copolymers (statistical or block copolymers ), diblock copolymers (SBR), triblock copolymers (SBRS or BRSBR), multiblock copolymers (BRSBRSBRS, S BRSBRSBR, etc.), styrene-isoprene-butadiene copolymers (statistical or block copolymers), tribloxopolymers (ISRIBRRR, SISBRS, SBRSIS, BRISIBRS, etc.), or mixtures thereof or combinations thereof. Illustrative star polymers include polymers containing a core and branches consisting of a polymer, including styrene and I or BD. Other illustrative examples include grafted copolymers of styrene and butadiene or isoprene. The solvent subsystems for use in the surfactant systems of the present invention are crude solvents, denoted by the abbreviation SS in the present description. Crude solvents are non-toxic biodegradable individual chemicals and / or mixtures of chemicals. For example, HF 1000 ™ is a biodegradable mixture of paraffins, olefins, naphthenes, esters and oxidation products. HF 1000 ™ is a low viscosity, pale yellow liquid having a flash point above 80 ° C (175 ° F) and a pour point of -7.2 ° C (19 ° F).

The surfactant composition according to the present invention includes from 0 wt.% To 100 wt.% Of the first surface active subsystem (FFS), from 100 wt.% To 0 wt.% Of the second surface active subsystem (FSS) and from 0 wt. % to 100 wt.% solvent subsystem (SS) based on the mass percentage of surface-active subsystems. The compositions of the compositions and an effective amount of the composition are adapted for foaming a fluid including spectroscopically analyzed crude oil and / or condensate present in the reservoir.

Spectroscopic analysis of operational fluids

The present invention includes spectroscopic analysis of production fluids to determine the composition of components in a production fluid. If production fluids include a high aromatic content similar to that of red diesel, the foam system of the present invention may include FSS surfactants in the presence or absence of FFS surfactants and in the presence or absence of solvents according to the present invention. If production fluids include low or no aromatics, the foaming system of the present invention may include FFS surfactants in the presence or absence of FSS surfactants and in the presence or absence of solvents of the present invention. In all other cases, the foaming system according to the present invention is a combination of surfactants FFS and FSS in the presence or absence of solvents according to the present invention, where the amount of surfactants FFS and FSS is controlled depending on the nature of the condensates and / or crude oil in operational fluids: more aromatic in nature requires higher proportions of FSS surfactants; a less aromatic character requires higher proportions of FFS surfactants in the presence or absence of solvents according to the present invention.

Drilling fluids

Typically, drilling mud is used while drilling a well. Drilling fluids can be used for so-called drilling under reduced pressure (hydrostatic pressure of the drilling fluid below the pore pressure of the formation), drilling at controlled pressure, where the hydrostatic pressure of the drilling fluid is controlled depending on the nature of the material through which drilling is carried out. Each type of drilling uses different types of drilling fluids. The compositions of the present invention are intended to improve the dispersion and stability of the resulting drilling fluids so that the cuttings remain suspended for longer periods of time or at temperatures up to 450 ° F (232 ° C).

Embodiments of the present invention relate to drilling fluid compositions comprising a surfactant system according to the present invention, where the surfactant system comprises from 0 wt.% To 100 wt.% Of the first surfactant subsystem, from 100 wt.% To 0 wt. % of the second surfactant subsystem and from 0 wt.% to 100 wt.% solvent subsystem based on the mass percentage of surfactant subsystems. The compositions of the compositions and an effective amount of the composition are adapted for foaming a fluid, including spectroscopically analyzed crude oil and / or condensate present in the reservoir.

Well completion solutions

Embodiments of the present invention relate to well completion compositions comprising a surfactant system according to the present invention, where the surfactant system comprises from 0 wt.% To 100 wt.% Of the first surfactant subsystem, from 100 wt.% To 0 wt.% the second surface-active subsystem and from 0 wt.% to 100 wt.% solvent subsystem based on the mass percentage of surface-active subsystems. The compositions of the compositions and an effective amount of the composition are adapted for foaming a fluid including spectroscopically analyzed crude oil and / or condensate present in the reservoir.

Hydraulic fracturing solutions

The present invention also relates to methods of hydraulic fracturing of a subterranean formation, comprising preparing a hydraulic fracturing solution comprising a surfactant system according to the present invention, and injecting the gel and coacervate down into the well, in the presence or absence of a proppant, and under sufficient pressure to fracture layer. Proppants suitable for the present invention include all commonly used or conventional proppants, including sand, shell rock and other solid particles. The fluid can be used in the absence of traditional salts forming a saline solution. Water-based gels used for hydraulic fracturing and other types of well treatment typically contain guar, cellulose or resins, depending on chemical bonding, and are sensitive to shear.

Embodiments of the present invention relate to hydraulic fracturing fluid compositions comprising a surfactant system according to the present invention, wherein the surfactant system comprises from 0 wt.% To 100 wt.% Of the first surfactant subsystem, from 100 wt.% To 0 wt.% Of the second surface-active subsystem and from 0 wt.% To 100 wt.% Of the solvent subsystem based on the mass percentage of surface-active subsystems. The compositions of the compositions and an effective amount of the composition are adapted for foaming a fluid including spectroscopically analyzed crude oil and / or condensate present in the reservoir.

Fluid Solutions

Embodiments of the present invention relate to formation stimulation fluid compositions comprising a surfactant system according to the present invention, wherein the surfactant system comprises from 0 wt.% To 100 wt.% Of the first surfactant subsystem, from 100 wt.% To 0 wt.% Of the second surface-active subsystem and from 0 wt.% To 100 wt.% Of the solvent subsystem based on the mass percentage of surface-active subsystems. The compositions of the compositions and an effective amount of the composition are adapted for foaming a fluid including spectroscopically analyzed crude oil and / or condensate present in the reservoir.

The compositions

In certain embodiments, the composition includes a weight ratio of the first surfactant subsystem and the second surfactant subsystem, which is from about 10: 1 to about 1:10. In other embodiments, the composition includes a weight ratio of the first surfactant subsystem and the second surfactant subsystem, which is from about 4: 1 to about 1: 4. In other embodiments, the composition includes a weight ratio of the first surfactant subsystem and the second surfactant subsystem, which is from about 7: 3 to about 3: 7. In other embodiments, the composition includes a weight ratio of the first surfactant subsystem and the second surfactant subsystem, which is from about 3: 2 to about 2: 3. In other embodiments, the composition includes a weight ratio of a first surfactant subsystem and a second surfactant subsystem, which is about 1: 1. In other embodiments, the composition includes a weight ratio of a first surfactant subsystem, a second surfactant subsystem, and a solvent subsystem, which is about 10: 1: 1 and about 1: 10: 1 and about 10: 1: 10 and about 1:10:10. In other embodiments, the composition includes a weight ratio of a first surfactant subsystem, a second surfactant subsystem, and a solvent subsystem, which is about 4: 1: 1 and about 1: 4: 1 and about 4: 1: 4 and about 1: 4: 4. In other embodiments, the composition includes a weight ratio of a first surfactant subsystem, a second surfactant subsystem, and a solvent subsystem, which is about 7: 3: 1 and about 3: 7: 1 and about 7: 3: 3, and about 3: 7: 3, and 7: 3: 7, and approximately 3: 7: 7. In other embodiments, the composition comprises a weight ratio of a first surfactant subsystem, a second surfactant subsystem, and a solvent subsystem, which is about 3: 2: 1 and about 2: 3: 1 and about 3: 2: 2, and about 2: 3: 2, and approximately 3: 2: 3, and approximately 2: 3: 3. In other embodiments, the composition comprises a weight ratio of a first surfactant subsystem, a second surfactant subsystem, and a solvent subsystem, which is about 1: 1: 0.1 and about 1: 1: 10.

For applications where production fluids include condensate that contains little or no aromatics, the foaming systems of the present invention include one or more FFS surfactants in a concentration of from about 1 vol.% To 20 vol.%. In other embodiments, the concentration is from about 5 vol.% To about 15 vol.%. In other embodiments, condensate foaming systems that contain little or no aromatics include one or more FFS and a solvent subsystem according to the present invention in a ratio of from about 1:50 to about 1: 1 in a concentration of from about 5 vol.% To 20 vol.%. In other embodiments, the concentration is from about 10 vol.% To about 15 vol.%.

For applications where production fluids include high aromatics crude oils or condensates, the foaming systems of the present invention include one or more FSS surfactants in a concentration of from about 7.5 vol.% To about 20 vol.%. In other embodiments, the implementation of the concentration is from 10 vol.% To about 20 vol.%.

For applications where production fluids include aromatic and non-aromatic condensates and crude oils that are determined by spectroscopic analysis of the fluids, the foaming system of the present invention includes a combination of FFS and FSS surfactants in the presence or absence of a solvent subsystem according to the present the invention, where surfactants comprise from about 1 vol.% to about 40 vol.%.

The compositions of the foaming compositions

The blowing agents of the present invention are usually added to the respective fluids in a volume percentage (vol.%) Of about 0.1 vol.% To about 30.0 vol.%. In certain embodiments, the blowing agents are added in a volume percent (vol.%) Ratio of about 1 vol.% To about 30.0 vol.%. In other embodiments, foaming agents are added in a volume percent (vol.%) Ratio of about 2 vol.% To about 30 vol.%. In other embodiments, the foaming agents are added in a volume percent (vol.%) Ratio of about 5 vol.% To about 30.0 vol.%.

Foam properties

The blowing agents of the present invention produce foams that have the general properties of a foam height of at least 150 ml, half-lives greater than or equal to about 2 minutes, the ability to cleanable, and a good foam texture. Foam, which has a good foam texture, is characterized by the presence of small bubbles of small medium size, in contrast to coarse foam, which has a large average size of bubbles. In other embodiments, the foam height is at least 160 ml and its half-life is greater than or equal to about 3 minutes. In other embodiments, the height of the foam is at least 170 ml and its half-life is greater than or equal to about 3 minutes. In other embodiments, the foam height is at least 180 ml and its half-life is greater than or equal to about 3 minutes.

Suitable reagents

Suitable fluorinated surfactants include, without limitation, any fluorinated surfactant capable of forming a stable condensate foam that contains little or no aromatic compounds. Illustrative examples of fluorinated surfactants having this property are surface active fluorinated aliphatic polymer esters (FAPEs). In certain embodiments, FAPE surfactants have an average molecular weight of at least 1,000,000 g / mol. In other embodiments, surface active fluorinated aliphatic polymeric esters (FAPEs) are surface active FAPEs described in international patent applications WO 2008/089391 A1 and WO 2008/089386 A2 and supplied by 3-M Innovative Properties Company (St. Paul, Minnesota, USA).

Suitable surfactants based on organosilicon compounds include, without limitation, any organosilicon surfactant capable of forming a stable foam with a condensate having a spectroscopically determined aromatic content and red diesel fuel. Illustrative examples of organosilicon surfactants having this property are DOW CORNING® SZ-1175, DOW CORNING® SZ-1180, DOW CORNING® SZ-1325E, DOW CORNING® SZ-1328E, DOW CORNING® SZ-1346E, DOW CORNING® 198 ADDITIVE, DOW CORNING® 5043 ADDITIVE, DOW CORNING® 5160 ADDITIVE, Sylgard® 309 (Wilbur-Ellis Company), Freeway® (Loveland Industries), Dyne-Amic® (Helena Chemical Company) and Silwet L-77® ( Loveland and Helena) or mixtures or combinations thereof.

Suitable fluorinated surfactants include, without limitation, a mixture of biodegradable non-toxic non-hazardous solvents containing biodegradable paraffins, olefins, naphthenes, esters and oxidation products having a flash point of at least 80 ° C and a pour point of about 19 ° F (-7, 2 ° C). Illustrative examples include terpenes and a mixture of terpenes derived from citrus plants, including HF 1000 ™, d-limonenes, orange terpenes, lemon terpenes, grapefruit terpenes, orange oil, lemon oil, other citrus terpenes, other citrus oils, or other mixtures and combinations thereof.

Suitable drilling fluid components

Suitable hydrocarbon basic fluids for use in the present invention include, without limitation, synthetic hydrocarbon fluids, petroleum-based hydrocarbon fluids, natural hydrocarbon (non-aqueous) fluids, or other similar hydrocarbons or mixtures or combinations thereof. Hydrocarbon fluids for use in the present invention have viscosities in the range of from about 5 x 10 ^-6 to about 600 x 10 ^-6 m ² / s (5 to about 600 centistokes). Illustrative examples of these hydrocarbon fluids include, but are not limited to, poly-α-olefins, polybutenes, polyol esters, vegetable oils, animal oils, other essential oils, low or high sulfur diesel fuel, kerosene, jet fuel, olefins with internal double bonds (IO) containing from about 12 to 20 carbon atoms, linear α-olefins containing from about 14 to 20 carbon atoms, poly-α-olefins containing from about 12 to about 20 carbon atoms hydrocarbons, isomerized α-olefins (IAO) containing from about 12 to about 20 carbon atoms, VM&P Naptha and Linpar paraffins from 13 to about 16 carbon atoms, and mixtures or combinations thereof.

Suitable poly-α-olefins (PAOs) include, without limitation, polyethylenes, polypropylenes, polybutenes, polypentenes, polyhexenes, polyheptenes, higher PAOs, their copolymers and mixtures thereof. Illustrative examples of PAO include PAO sold by Mobil Chemical Company, including fluids with Smooth Particle Hydrodynamics (SHF), and PAO sold by Ethyl Corporation under the name ETHYLFLO and currently sold by Albemarle Corporation under the trade name Durasyn. These fluids include those named ETHYLFLO 162, 164, 166, 168, 170, 174 and 180. Highly suitable PAOs for use in the present invention include mixtures containing approximately 56% ETHYLFLO (currently Durasyn 174) and approximately 44% ETHYLFLO (currently Durasyn 168).

Illustrative examples of polybutenes include, but are not limited to, sold by Amoco Chemical Company and Exxon Chemical Company under the trade names INDOPOL and PARAPOL, respectively. Highly polybutenes for use in the present invention include INDOPOL 100 from Amoco.

Illustrative examples of polyol esters include, but are not limited to, neopentyl glycols, trimethylol propanes, pentaerythritol, dipentaerythritol and diesters, including dioxyl sebacinate (DOS), dioctylazelinate (DOZ) and dioctyl adipate.

Illustrative examples of petroleum-based fluids include, but are not limited to, petroleum jelly oils, paraffin oils, and medium viscosity index (MVI) naphthenic oils having viscosities in the range of from about 5 • 10 ^-6 to about 600 • 10 ^-6 m ² / s (5 to about 600 centistokes) at 40 ° C. Illustrative examples of petrolatum mineral oils include oils sold by Witco Corporation, Arco Chemical Company, PSI, and Penreco. Illustrative examples of paraffin oils include neutral solvent oils from Exxon Chemical Company, neutral high viscosity index (HVI) oils supplied by Shell Chemical Company, and solvent-treated neutral oils supplied by Arco Chemical Company. Illustrative examples of MVI naphthenic oils include solvent-extracted pale yellow oil distillate oils obtained from Exxon Chemical Company, solvent-extracted / acid-treated MVI oils supplied by Shell Chemical Company, and naphthenic oils sold under the names HydroCal and Calsol Calumet.

Illustrative examples of vegetable oils include, but are not limited to, castor oils, corn oil, olive oil, sunflower oil, sesame oil, peanut oil, other vegetable oils, modified vegetable oils, including crosslinked castor oils and the like, and mixtures thereof . Illustrative examples of animal oils include, but are not limited to, mink fat, lard, other animal oils, and mixtures thereof. Other essential oils also work well. Of course, you can also use mixtures of all of the above oils.

Suitable blowing agents for use in the present invention include, without limitation, any blowing agent suitable for foaming hydrocarbon-based drilling fluids. Illustrative examples of foaming agents include, but are not limited to, silicone foaming agents, including tetra (trimethylsiloxane) silane, fluorinated oligomeric or polymeric foaming agents, including fluorinated methacrylic copolymer, or other similar foaming agents capable of foaming in hydrocarbon or oil based drilling fluids, or mixtures or combinations thereof. Illustrative examples of these blowing agents include, without limitation, DC-1250, supplied by Dow Corning; Zonyl FSG supplied by DuPont; APFS-16, available from Applied Polymer; A4851, available from Baker Petrolite; Superfoam supplied by Oilfield Solutions; Paratene HFA supplied by Woodrising; DVF-880, available from Parasol Chemicals INC., JBR200, JBR300, JBR400 and JBR500, available from Jeneil Biosurfactant Company; Paratene HFA, Paratene HFB, Paratene MFA, Paratene MFB, supplied by Woodrising Resources Ltd., or mixtures or combinations thereof.

Suitable polymers for use in the present invention include, without limitation, any polymer soluble in a basic hydrocarbon fluid. Illustrative polymers include, without limitation, a polymer comprising units of one or more (one, two, three, four, five, ..., any desired amount) of polymerizable monoolefins or diolefins. Illustrative examples include, but are not limited to, polyethylene, polypropylene, polybutylene or other poly-α-olefins, polystyrene or other aromatic polyolefins, polybutadiene, polyisoprene or other polydiolefins or their copolymers (a polymer comprising two or more monoolefins or diolefins), or copolymers, including a small amount of other copolymerizable monomers, including acrylates (acrylic acid, methyl acrylate, ethyl acrylate, etc.), methacrylates (methacrylic acid, methyl methacrylate, ethyl methacrylate, etc.), vinyl acetate tat, maleic anhydride, succinic anhydride and the like, provided, of course, that the resulting polymer is soluble in a basic hydrocarbon-based fluid.

Suitable gelling agents for use in the present invention include, without limitation, any gelling agent. Illustrative examples of gelling agents include phosphoric acid esters, a copolymer of ethylene and acrylic acid, copolymers of ethylene and methacrylic acid, copolymers of ethylene and vinyl acetate, copolymers of ethylene and maleic anhydride, copolymers of butadiene and methacrylic acid, copolymers of ethylene and butadiene, butylene acid copolymers of styrene, butadiene and methacrylic acid, or another copolymer comprising monomers containing acidic fragments, or mixtures or combinations thereof. Illustrative examples of phosphoric acid ester gels include, but are not limited to, WEC HGA 37, WEC HGA 70, WEC HGA 71, WEC HGA 72, WEC HGA 702, or a mixture or combination thereof supplied by Weatherford International. Other suitable gelling agents include, but are not limited to, Geltone II, available from Baroid; Ken-Gel supplied by Imco, etc.

Suitable crosslinking agents for use in the present invention include, without limitation, any suitable crosslinking agent for use with gelling agents. Illustrative crosslinking agents include, but are not limited to, divalent and trivalent metal salts, including calcium salts, magnesium salts, barium salts, monovalent copper salts, divalent copper salts, ferric salts, aluminum salts, or a mixture or combination thereof. Illustrative examples of a crosslinking agent for use with phosphoric acid esters include, but are not limited to, WEC HGA 44, WEC HGA 48, WEC HGA 55se, WEC HGA 55s, WEC HGA 61, WEC HGA 65, or mixtures or combinations thereof supplied by Weatherford International .

Suitable defoamers for use in the present invention include, without limitation, any defoamer capable of reducing the height of the foam of the foamed drilling mud system of the present invention. Illustrative examples of defoamers are low molecular weight alcohols, with isopropanol or isopropyl alcohol (IPA) being preferred.

Gases

Suitable gases for foaming a foaming ion-bound gel composition include, without limitation, nitrogen, carbon dioxide, or any other gas suitable for use in hydraulic fracturing, or mixtures or combinations thereof.

Corrosion inhibitors

Suitable corrosion inhibitors for use in the present invention include, without limitation, quaternary ammonium salts, for example, chlorides, bromides, iodides, dimethyl sulfates, diethyl sulfates, nitrites, bicarbonates, carbonates, hydroxides, alkoxides and the like, or mixtures or combinations thereof ; salts of nitrogenous bases or mixtures or combinations thereof. Exemplary quaternary ammonium salts include, but are not limited to, quaternary ammonium salts derived from an amine and a quaternization agent, for example, alkyl chlorides, alkyl bromides, alkyl iodides, alkyl sulfates, including dimethyl sulfate, diethyl sulfate, etc., dihalogenated alkanes, including dichloroethane, dichloropropane, dichloroethyl ether, alcohol adducts of epichlorohydrin, ethoxylates, etc. or mixtures or combinations thereof; and amine agents, for example, alkyl pyridines, in particular highly alkyl alkyl pyridines, alkyl quinolines, synthetic tertiary amines C6-C24, amines derived from natural products, including coconuts and the like, dialkyl substituted methylamines, amines obtained by the reaction of fatty acids or oils and polyamines, diethylenetriamine amidoimidazolines (DETA) and fatty acids, ethylene diamine imidazolines, diaminocyclohexane imidazolines, aminoethylethylenediamine imidazolines, propanediamine and alkylated propene diamine, hydroxyalkylated s mono- and polyamines sufficient to convert all labile hydrogen atoms in the amines to oxygen containing groups, and the like, or mixtures or combinations thereof. Illustrative examples of salts of nitrogenous bases include, without limitation, salts of nitrogenous bases derived from salts, for example, C1-C8 monocarboxylic acids, including formic acid, acetic acid, propionic acid, butyric acid, valerianic acid, caproic acid, heptanoic acid, caprylic acid, 2-ethylhexanoic acid and the like; dicarboxylic acids C2-C12, unsaturated carboxylic acids and anhydrides C2-C12, and the like; polyacids, including diglycolic acid, aspartic acid, citric acid and the like; hydroxy acids, including lactic acid, itaconic acid and the like; aryl and hydroxyaryl acids; natural or synthetic amino acids; thioacids, including thioglycolic acid (TGA); free acid forms of derivatives of phosphoric acid and glycol, ethoxylates, ethoxylated amines and the like, and amino sulfonic acids; or mixtures thereof or combinations and amines, for example amines of high molecular weight fatty acids, including cocoamine, amines of solid fatty acids, and the like; amines of hydroxyalkylated fatty acids; polyamines (di-, tri-, tetra- or higher) of high molecular weight fatty acids; oxyalkylated fatty acid polyamines; aminoamides, including reaction products of carboxylic acids with polyamines, where there are less equivalents of carboxylic acid than equivalents of reacting amines, and their hydroxyalkylated derivatives; fatty acid pyrimidines; ethylene diamine monoimidazolines (EDA), DETA or higher ethylene amines, hexamethylene diamine (HMDA), tetramethylene diamine (TMDA) and their higher analogues; bisimidazolines, imidazolines of mono - and polyorganic acids; oxazolines derived from monoethanolamine and fatty acids or oils, fatty acid esters amines, aminoethylpiperazine mono- and bisamides; salts of GAA and TGA and reaction products of crude tall oil or distilled tall oil with diethylene triamine; salts of GAA and TGA and reaction products of dimeric acids with mixtures of polyamines, including TMDA, HMDA and 1,2-diaminocyclohexane; a salt of TGA and imidazoline obtained from DETA with tall oil fatty acids or soybean oil, canola oil and the like; or mixtures or combinations thereof.

Other additives

Drilling fluids according to the present invention may also include other additives, including scale inhibitors, carbon dioxide control additives, paraffin control oxygen control additives, or other additives.

Sediment control

Suitable additives to control the formation of deposits that are useful in the compositions of the present invention include, but are not limited to, chelating agents, for example, salts of Na ⁺ , K ⁺ or NH ₄ ⁺ and ethylenediaminetetraacetic acid (EDTA); salts of Na ⁺ , K ⁺ or NH ₄ ⁺ and nitrilotriacetic acid (NTA); salts of Na ⁺ , K ⁺ or NH ₄ ⁺ and erythorbic acid; salts of Na ⁺ , K ⁺ or NH ₄ ⁺ and thioglycolic acid (TGA); salts of Na ⁺ , K ⁺ or NH ₄ ⁺ and hydroxyacetic acid; salts of Na ⁺ , K ⁺ or NH ₄ ⁺ and citric acid; salts of Na ⁺ , K ⁺ or NH ₄ ⁺ and tartaric acid or other similar salts or mixtures or combinations thereof. Suitable additives that work on threshold effects, complexing agents include, without limitation: phosphates, for example sodium hexamethylphosphate, linear phosphate salts, polyphosphoric acid salts, phosphonates, for example non-ionic ones, including HEDP (hydroxyethylidene diphosphoric acid), PBTC (phosphonoisobutantricarboxylic acid) aminophosphonates MEA (monoethanolamine), NH ₃ , EDA (ethylenediamine), bishydroxyethylene diamine, bisaminoethylether, DETA (diethylenetriamine), HMDA (hexamethylenediamine), higher homologues and isomers of HMDA, polyamines EDA and DETA o homologues, or similar polyamines, or mixtures or combinations thereof; phosphoric acid esters, for example polyphosphoric acid esters or phosphorus pentoxide esters (P ₂ O ₅ ) and alkanolamines, including MEA, DEA, triethanolamine (TEA), bishydroxyethylethylenediamine; ethoxylated alcohols, glycerin, glycols, including EG (ethylene glycol), propylene glycol, butylene glycol, hexylene glycol, trimethylolpropane, pentaerythritol, neopentyl glycol and the like; tri- and tetrahydroxyamines; ethoxylated alkyl phenols (use is limited due to toxicity problems), ethoxylated amines, including monoamines, for example N-methyldiethanolamine (MDEA) and higher amines containing from 2 to 24 carbon atoms, diamines containing from 2 to 24 carbon atoms, etc. .; polymers, for example, aspartic acid homopolymers, soluble acrylic acid homopolymers, acrylic acid and methacrylic acid copolymers, acylate terpolymers, 2-acrylamido-2-methylpropanesulfonic acid (AMPS), etc., hydrolyzed polyacrylamides, polyblock acid anhydride (PMA) and t .P.; or mixtures or combinations thereof.

Carbon dioxide neutralization

Suitable additives to neutralize CO ₂ and for use in the compositions of the present invention include, without limitation, MEA, DEA, isopropylamine, cyclohexylamine, morpholine, diamines, dimethylaminopropylamine (DMAPA), ethylenediamine, methoxypropylamine (MOPA), dimethylethanolamine, methyldiethanolamine (MD) oligomers, imidazolines EDA and homologs and higher adducts, imidazolines aminoethylethanolamine (AEEA), aminoethylpiperazine, aminoethylethanolamine, diisopropanolamine, AMP-90 ™ and Angus AMP-95 from DOW, dialkylamino, ethyl, ethyl, ethyl, methyl, ethyl, ethyl and opropil), trialkyl amines (methyl, ethyl, isopropyl), bisgidroksietiletilendiamin (THEED) and the like, or mixtures or combinations thereof.

Paraffin control

Suitable additives for the removal, dispersion of paraffins and / or crystalline distribution of paraffins include, without limitation, cellosolves, which are supplied by DOW Chemicals Company; cellosolve acetate; ketones; salts and esters of acetic and formic acids; surfactants containing ethoxylated or propoxylated alcohols, alkyl phenols and / or amines; methyl alcohol esters, including methyl esters of fatty acids of coconut oil, lauric acid, soybean oil fatty acids or methyl esters of other naturally occurring fatty acids; sulfonated methyl alcohol esters, including sulfonated methyl esters of coconut oil, lauric acid, soybean oil fatty acids or sulfonated methyl esters of other naturally occurring fatty acids; chlorides of low molecular weight quaternary ammonium bases of fatty acids of coconut oil, soybean oil, or amines C10-C24, or monohalogenated alkyl and aryl chlorides; quaternary ammonium salts containing bisubstituted (for example, wild-, etc.) and low molecular weight halogenated alkyl and / or aryl chlorides; dimeric quaternary salts of dialkyl (methyl, ethyl, propyl, mixed, etc.) tertiary amines and dihalogenated ethanes, propanes, etc. or dihalogenated ethers, including dichloroethyl ether (DCEE) and the like; dimeric quaternary salts of alkyl amines or amidopropylamines, including cocoamidopropyl dimethyl, DCEE bis quaternary ammonium salts; or mixtures or combinations thereof. Suitable alcohols used in the preparation of surfactants include, but are not limited to, linear or branched alcohols, in particular mixtures of alcohols reacted with ethylene oxide, propylene oxide or higher alkylene oxide, where the resulting surfactants have different hydrophilic-lipophilic balances (HLB). Suitable alkyl phenols used in the preparation of surfactants include, but are not limited to, nonyl phenol, decyl phenol, dodecyl phenol or other alkyl phenols, wherein the alkyl group contains from about 4 to about 30 carbon atoms. Suitable amines used in the preparation of surfactants include, but are not limited to, ethylene diamine (EDA), diethylene triamine (DETA), or other polyamines. Illustrative examples include Quadrols, Tetrols, Pentrols, which are supplied by BASF. Suitable alkanolamines include, without limitation, monoethanolamine (MEA), diethanolamine (DEA), reaction products of MEA and / or DEA with coconut oils and acids.

Oxygen control

The introduction of water into the well is often accompanied by an increase in the oxygen content in the downhole fluids due to oxygen dissolved in the introduced water. Thus, the materials introduced into the well should work in oxygen environments or should work well enough until the oxygen content decreases due to natural reactions. In the case of a system that cannot operate in oxygen, oxygen must be removed or controlled in any material introduced into the well. This problem is exacerbated in the winter, when the input materials include preparations for winter, including water, alcohols, glycols, cellosolves, formates, acetates, etc., and because the solubility of oxygen rises to a level of about 14-15 m d. in very cold water. Oxygen can also enhance corrosion and scale formation. In QGT applications (capillary flexible tubes) using dilute solutions, the introduction of solutions leads to the introduction of an oxidizing medium (O ₂ ) into the reducing medium (CO ₂ , H ₂ S, organic acids, etc.).

Oxygen control options include: (1) removing air from the fluid before being injected into the well, (2) adding normal sulfides to the sulfur oxides contained in the product so that these sulfur oxides do not accelerate the effect of acid on metal surfaces, (3) adding erythorbates, ascorbates, diethylhydroxyamine or other oxygen-reactive compounds that are added to the fluid before being introduced into the well; and (4) the addition of corrosion inhibitors or metal passivating agents, including potassium (alkaline) salts of glycol esters, polyhydric alcohol ethoxylates, or other similar corrosion inhibitors. Illustrative examples of oxygen control agents and corrosion inhibitors include mixtures of tetramethylene diamines, hexamethylene diamines, 1,2-diaminocyclohexane, amine head fractions or reaction products of these amines with partial molar equivalents of aldehydes. Other oxygen control agents include amides of salicylic and benzoic acids and polyamines, especially those used under alkaline conditions, short-chain acetylenediols or similar compounds, phosphoric acid esters, boric acid and glycerol esters, urea and thiourea and bisoxalidine salts, or other compounds that absorb oxygen react with oxygen or otherwise reduce the oxygen concentration or eliminate it.

Salt inhibitors

Suitable salt inhibitors for use in the fluids of the present invention include, but are not limited to, the Na Minus nitrilotriacetamide salt, which is available from Clearwater International, LLC (Houston, Texas).

Defoamers

Suitable defoamers for use in the present invention include, without limitation, any defoamer capable of reducing the height of the foam of the foamed drilling mud system of the present invention. Illustrative examples of defoamers are Dow Corning defoamers, including Dow Corning 200 (R).

Foam characteristics

Typically, the foaming hydrocarbon drilling fluid systems of the present invention having an initial fluid amount of 100 ml produce a foam having a height of at least about 400 ml and a half life of at least about 2 minutes. In particular, the resulting foam will have a height of from about 400 ml to about 800 ml and a half-life of from about 2 minutes to about 15 minutes or more, depending on the application and the exact composition of the hydrocarbon fluid according to the present invention. The stability or half-life and height of the resulting foam is controlled by the amount and type of thickeners in the composition, the amount and type of foaming agents in the composition, the amount of gas and type of gas in the composition, temperature of the composition and pressure of the composition. As a rule, with an increase in the number of thickeners and / or foaming agents, an increase in the stability and height of the foam is possible. Typically, thickeners increase resistance more than the height of the foam, while foaming agents increase the height of the foam. Of course, the height of the foam is also directly proportional to the amount and type of gas dissolved or absorbed in the fluid.

The experimental part of the invention

Foam test

In a foam test, a laboratory mixer from Hamilton Beach was investigated. The mixing procedure was carried out to mix the studied drilling fluids with high speed for from 45 seconds to 60 seconds, noting any changes at 15-second intervals. The investigated concentration of the foaming agent was established as in the present description. After foaming with a mixer, the studied drilling fluids were poured into a 1000 ml or 500 ml volumetric cylinder to determine the linearity of the foam measurements. The height of the foam was the volume (ml) occupied by the foam after it was poured into the cylinder. The half-life was the time during which the foam volume decreased by 50% relative to the initial foam volume; for example, if the initial volume was 500 ml when measured in a 1000 ml volumetric cylinder, then the half-life was the time when the volume of the foam decreased to a level of 250 ml.

It has been shown that the surfactant systems of the present invention provided the desired properties of the foam in condensates, regardless of the degree of unsaturation or aromatic compounds in the condensate. In fact, it is now possible, based on an initial analysis of the composition of the condensate or crude oil, to adapt the surface-active system according to the present to work as the initial foaming system of the condensate or crude oil of this reservoir. As shown in table 1, the resulting properties of the foam obtained from mixtures of surfactants FFS and FSS are superior to the properties obtained from individual substances FFS or FSS.

Table 1
Evaluation of surfactants FFS and FSS for red diesel Composition Foam Height (ml) Half-life (min: sec) Notes Ffs ^a 176 3 o'clock Pure destruction Ffs ^a 200 3:30 A stable emulsion was observed. 7FFS: 3FSS 160 3 o'clock Excellent clean destruction 3FFS: 7FSS 180 3 o'clock Superb Foam Texture / Superb Clean Destruction 1FFS: 1FSS 168 3 o'clock Excellent clean destruction A foaming system was added at a concentration of 1 vol.%.
FFS is a surface active fluorinated aliphatic polymer ester, supplied by 3M.
FSS is an organosilicon surfactant marketed by Weatherford under the trade name OleoFoam C ™.
^a FAPE is a solution containing 20 wt.% of surface-active fluorinated aliphatic polymer esters, supplied by 3M.

A brief overview of the foaming properties of the FFS and FSS surfactants in foaming condensates having different properties is given in Table 2.

table 2
Evaluation of fluorinated aliphatic polymer esters with condensates Composition Foam Height (ml) Half-life (min: sec) Notes FSS (≤10 vol.%) + Crude oil (36 API) 180 5: 0 High compatibility FFS ^a (≤5 vol.%) + Crude oil (36 API) 0 0 Incompatibility FFS ^a (≤5 vol.%) + C-3 ^b 0 0 Incompatibility Ffs (15 vol.%) + C-3^b 170 0:40 Unique property Ffs (1.0 vol.%) + 50 ml C-3^b+ 50 ml SS 180 1:00 Thinner effect Ffs (2.0 vol.%) + 50 ml C-3^b+ 50 ml SS 180 1:35 Thinner effect Ffs (10 vol.%) + C-2^c 280 2:40 Unique property Ffs (15 vol.%) + C-2^c 300 3 o'clock Unique property FFS is a surface active fluorinated aliphatic polymer ester, supplied by 3M.
FSS is an organosilicon surfactant marketed by Weatherford under the trade name OleoFoam C ™.
SS is a solvent system according to the present invention.
^a FAPE is a solution containing 20 wt.% of surface-active fluorinated aliphatic polymer esters, supplied by 3M.
^b C-3 is a condensate-3.
^c C-2 is a condensate-2.

The surfactant systems of the present invention are unique in their ability to serve as effective and efficient lifting systems for crude oil, condensate, or mixtures thereof with water at various concentrations. Essentially, with the surfactant systems of the present invention, various hydrocarbons, including pure local crude oil, condensates, internal double bond olefins, synthetic and other hydrocarbons, or mixtures thereof, and combinations can now be foamed and used in drilling applications and softening applications to increase production from reservoirs.

Until now, gushing wells containing condensates with surfactants have been an intractable task. Similarly, during drilling operations, condensate emissions easily destroy (quench or destroy) foam-forming drilling fluids. Such impaired performance of the foam of the drilling fluid due to the release of condensate can lead to malfunctions or costly restoration of normal operating parameters. However, careful planning now allows condensate to be extracted from the wells.

Most of the condensate composition depends on the well; therefore, the characteristics of the condensate in question are first established spectroscopically in order to obtain a characteristic profile of the condensate or production fluids in general in the reservoir, which is opened or operated. After this, the condensate is combined with a surfactant having the desired characteristics, resulting in a stable foam having the desired foam height and half-life. The condensate characterization classifies the condensate with respect to its composition, including aromatic compounds, non-aromatic compounds, aliphatic compounds and / or naphthalene compounds, using Fourier Transform Infrared Spectroscopy (FT-IR) or other spectroscopic methods that allow classifying the composition of the condensate. This classification represents the first step in a method for producing a surfactant system according to the present invention, which will provide a stable foam in a fluid containing condensate. This stage is sometimes called the stage of diagnosis.

Now consider FIG. 1, representing the superposition of FT-IR spectra of aromatic and non-aromatic condensates with respect to red diesel fuel. From the FT-IR spectra of condensate-1 (C-1), condensate-2 (C-2), condensate 3 (C-3) and red diesel fuel, it is clear that these four materials have many similar lines in the IR spectrum. In the classification, condensates with significant absorption in the region corresponding to aromatic compounds can be distinguished from condensate containing a small or zero amount of aromatic compounds. C-1 and red diesel show absorption at 1607 cm ^-1 and a shoulder of about 1495 cm ^-1 , including absorption of about 1501 cm ^-1 , which is characteristic of ring stretching vibrations ν _{C = C of} compounds containing aromatic rings, while as C-2 does not show these absorption lines, which corresponds to condensates containing a small or zero amount of aromatic compounds. C-3 is less aromatic than C-1, but more aromatic than C-2.

The silicone surface-active FSS system forms a stable foam in C-1 as well as in red diesel, while the FAPE surface-active FFS system forms a stable foam in C-2. As a result, FFS systems turned out to be incompatible with non-aromatic condensates, while FSS systems turned out to be compatible with aromatic condensates. Thus, it is possible to formulate a surfactant system that exhibits the desired properties of the foam for a given production fluid, after examination and obtaining a profile of the characteristics of the fluid.

Once a condensate or crude oil profile is obtained, it is possible to formulate a surfactant system according to the present invention to obtain a stable foam in a fluid such as drilling fluid, production fluid, lifting fluid, hydraulic fracturing solution and / or solution for impacting formation containing condensate and / or crude oil. In certain embodiments, the surfactant system comprises a mixture of surfactants FFS and FSS. In other embodiments, a surfactant system comprises a mixture of FFS and FSS surfactants and a solvent system according to the present invention. In other embodiments, a surfactant system comprises one FFS surfactant or a plurality of FFS surfactants and a solvent system according to the present invention. As shown in Table 2, FFS surfactants do not form stable foams in Condensate-1 (C-1) containing fluids, but stable foams were obtained when the solvent system of the present invention was used as a diluent.

All documents cited herein are incorporated by reference. Although the present invention is described with reference to its preferred embodiments, having read the present description, those skilled in the art can appreciate the changes and modifications that can be made and that do not go beyond the scope and do not deviate from the spirit of the present invention, as described above and stated below in the claims.

Claims (20)

1. A surface-active composition comprising
a first surface active subsystem containing a fluorinated surface active subsystem,
a second surface-active subsystem containing an organosilicon surface-active subsystem, and
optionally a solvent subsystem, where the composition is adapted for foaming a fluid including spectroscopically analyzed crude oil and / or condensate present in the reservoir. 2. The composition according to claim 1, in which the mass ratio of the first surface-active subsystem and the second surface-active subsystem is from about 10: 1 to about 1:10. 3. The composition according to claim 1, in which the mass ratio of the first surface-active subsystem and the second surface-active subsystem is from about 4: 1 to about 1: 4. 4. The composition according to claim 1, in which the mass ratio of the first surface-active subsystem and the second surface-active subsystem is from about 7: 3 to about 3: 7. 5. The composition according to claim 1, in which the mass ratio of the first surface-active subsystem and the second surface-active subsystem is from about 3: 2 to about 2: 3. 6. The composition according to claim 1, in which the mass ratio of the first surface-active subsystem and the second surface-active subsystem is approximately 1: 1. 7. The composition according to claim 1, in which the mass ratio of the first surface-active subsystem, the second surface-active subsystem and the solvent subsystem is approximately 10: 1: 1, and approximately 1: 10: 1, and approximately 10: 1: 10, and about 1:10:10. 8. The composition according to claim 1, in which the mass ratio of the first surface-active subsystem, the second surface-active subsystem and the solvent subsystem is approximately 4: 1: 1, and approximately 1: 4: 1, and approximately 4: 1: 4, and approximately 1: 4: 4. 9. The composition according to claim 1, in which the mass ratio of the first surface-active subsystem, the second surface-active subsystem and the solvent subsystem is between about 7: 3: 1, and about 3: 7: 1, and about 7: 3: 3 and about 3: 7: 3 and 7: 3: 7 and about 3: 7: 7. 10. The composition according to claim 1, in which the mass ratio of the first surface-active subsystem, the second surface-active subsystem and the solvent subsystem is from about 3: 2: 1 to about 2: 3: 1, and about 3: 2: 2, about 2: 3: 2; and from about 3: 2: 3 to about 2: 3: 3. 11. The composition according to claim 1, in which the mass ratio of the first surface-active subsystem, the second surface-active subsystem and the solvent subsystem is between about 1: 1: 0.1 and about 1: 1: 10. 12. The composition of the drilling fluid containing a surface-active system, including
a first surface active subsystem containing a fluorinated surface active subsystem,
a second surface-active subsystem containing an organosilicon surface-active subsystem, and
optionally a solvent subsystem, where the system is adapted for foaming a mud composition comprising a spectroscopically analyzed crude oil and / or condensate present in a reservoir. 13. The composition of the solution for completion, containing a surface-active system, including
a first surface active subsystem containing a fluorinated surface active subsystem,
a second surface-active subsystem containing an organosilicon surface-active subsystem, and
optionally a solvent subsystem, where the system is adapted to expand the composition of the completion fluid, including the spectroscopically analyzed crude oil and / or condensate present in the reservoir. 14. The composition of the hydraulic fracturing solution containing a surface-active system, including
a first surface active subsystem containing a fluorinated surface active subsystem,
a second surface-active subsystem containing an organosilicon surface-active subsystem, and
optionally a solvent subsystem, where the system is adapted for foaming a hydraulic fracturing solution composition including the spectroscopically analyzed crude oil and / or condensate present in the reservoir. 15. The composition of the solution for stimulating the formation containing a surface-active system, including
a first surface active subsystem containing a fluorinated surface active subsystem,
a second surface-active subsystem containing an organosilicon surface-active subsystem, and
optionally a solvent subsystem, where the system is adapted to expand the composition of the solution to act on the formation, including the spectroscopically analyzed crude oil and / or condensate present in the reservoir. 16. A method of foaming a fluid containing crude oil and / or condensate, including
analysis of crude oil and / or condensate from the reservoir,
preparation of a surface active system including
a first surface active subsystem containing a fluorinated surface active subsystem,
a second surface-active subsystem containing an organosilicon surface-active subsystem, and
optionally a solvent subsystem, where the system is adapted for foaming a fluid including analyte crude oil and / or condensate,
adding an effective amount of a surfactant system to the wellbore fluid, where the effective amount is sufficient to form a stable foam when gas is added, and
adding a foaming amount of gas to the borehole fluid sufficient to convert the fluid into a stable foam. 17. The method according to clause 16, in which the downhole fluid is a drilling fluid, and this method further includes
injecting the drilling fluid into the borehole while drilling through the drill bit, where the fluid contains a surface-active system comprising a first surface-active subsystem containing a fluorinated surface-active subsystem, a second surface-active subsystem containing an organosilicon surface-active subsystem, and optionally a solvent subsystem, where the system is adapted for foaming a fluid including analyte crude oil and / or condensate, and
introducing an effective amount of gas for foaming the drilling fluid to obtain a stable foam of the drilling fluid. 18. The method according to clause 16, in which the downhole fluid is a solution for hydraulic fracturing, and this method further includes
injection of a hydraulic fracturing solution into a reservoir under conditions of formation of cracks in the formation in the presence or absence of a proppant, where the fluid contains a surface-active system comprising a first surface-active subsystem containing a fluorinated surface-active subsystem, a second surface-active a subsystem containing an organosilicon surfactant subsystem, and optionally a solvent subsystem, and where the system is adapted to foam fluid containing the analyzed crude oil and / or condensate. 19. The method according to clause 16, in which the downhole fluid is a lifting solution, and this method further includes
injecting an effervescent effective amount of gas and a lifting solution into a finished and productive formation to produce a stable lifting foam that reduces the weight of the column and improves production, where the lifting solution contains an effective amount of a surface-active system comprising a first surface-active subsystem containing a fluorinated surface-active subsystem , a second surfactant subsystem containing an organosilicon surfactant subsystem, and optionally a solution subsystem viewer, where the system is adapted for foaming a fluid, including the analyzed crude oil and / or condensate. 20. The method according to clause 16, in which the downhole fluid is a solution for stimulating the formation, and this method further includes
injection of a foaming effective amount of gas and solution to act on the formation into a finished and productive formation to produce stable foam under conditions of heating and pressure sufficient to introduce foam into the formation to improve production, where the lifting solution contains an effective amount of a surfactant system including the first a surface-active subsystem containing a fluorinated surface-active subsystem, a second surface-active subsystem containing an organosilicon surface su- subsystem, subsystem, and optionally a solvent, wherein the system is adapted for foaming fluid consisting analyzed crude oil and / or condensate.

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