Method of oil extraction from oil deposit

FIELD: oil-and-gas production.

SUBSTANCE: proposed method comprises the following steps: a) forcing flooding fluid into deposit, and b) extracting oil from borehole in location other than that of forcing flooding liquid. Flooding liquid includes water and some amount of one or more specified viscoelastic nonpolymeric surfactants sufficient for interfacial surface tension approximating to 1 mNm or smaller, and viscosity of 10 sP or larger. Proposed invention is developed in dependent claims.

EFFECT: higher efficiency of tertiary oil extraction.

24 cl

 

The technical FIELD TO WHICH the INVENTION RELATES.

The present invention relates to a method of extracting oil from oil fields.

The LEVEL of TECHNOLOGY

For the extraction of crude oil from oil fields (underground oil-bearing formations) has been used in various ways. Primary mining methods are usually based on natural pressure field, which allows you to make a selection or extraction of oil. Secondary mining methods typically include the increase of pressure in the field through the introduction (injection) energy by water flooding, steam or gases, but not in the location of the well and towards the hole. With the introduction of water this method is called flooding. Then the oil is extracted from the well. Tertiary production methods typically include increased production in more complicated ways, such as heating, rheological modification flooding liquids, as well as modification of the reservoir and/or of the pore geometry.

One of the primary methods of extraction involves pumping water through the well field to its opening, or rupture, which leads to the recovery of additional oil. Water can also be used to carry proppants, such as sand, to keep open the pores and gaps in the seams after buscavage under pressure, which further increases the yield of oil.

In the tertiary production method during flooding was pumped liquid, which are aqueous solutions/dispersions of surface-active substances. For the specified use have been described, some anionic and nonionic surfactants, such as alkylphenol sulfonates, esters, oxyalkylated aliphatic alcohols and oxyalkylated ALKYLPHENOLS. Surfactants reduce the interfacial tension (IFT) of the liquid and allow it to more easily form a mixture of emulsions and/or microemulsions of oil in the field. The formation of mixtures and/or microemulsions allows to displace the oil contained in the reservoir, through the reduction of IFT and solubilization of oil in aqueous solutions of surfactants, increasing, thus, the production of oil from underground reservoirs. However, fluids with additives surfactants have lower viscosity than oil, so their effectiveness in the displacement of oil from the reservoir is limited.

For a more efficient displacement of oil from an underground reservoir, the viscosity of the flooding fluid was increased by adding high molecular weight polymers, such as polyacrylamide (PAM). Such high molecular weight polymers have also been used in combination with usually the YMI anionic surface-active substances.

The disadvantage of using in flooding liquids only conventional anionic surfactants is that the primary physical effect of the latter is to reduce the IFT without significantly increasing the viscosity. The disadvantage of using pure high molecular weight polymers is that they do not reduce the IFT. Combining conventional anionic surface-active substances with a high molecular weight polymer in order to achieve both the reduction of IFT, and increasing the viscosity requires the use of two different components, which can be costly and difficult. In addition, some conventional anionic surfactants can exhibit undesirable high molecular weight polymers and to prevent increase in the viscosity. Moreover, high molecular weight polymers are often adsorbed or deposited in the field, damaging the reservoir and reducing oil production.

It would be desirable to have a flooding fluid and method of its use in tertiary oil extraction method, which uses a single additive or component that produces a significant reduction of IFT and a significant increase in the viscosity of the flooding fluid.

The INVENTION

The present invention is a method of oil production from the field.

Also the purpose of this and the finding is tertiary oil extraction method from the field, uses a flooding fluid comprising a single additive or component that produces a significant reduction of IFT and a significant increase in the viscosity of the flooding fluid.

Under these and other objectives of the present invention describes a method of increasing oil production from the field. This method involves the following stages (a) introducing a flooding fluid into the field, and b) extracting the oil through the hole located at a location other than the point of introduction of the flooding fluid in the field. Flooding fluid includes water and a certain amount of one or more polimernyh viscoelastic surfactants sufficient to ensure the values of the interfacial surface tension of about 1 millinewton per meter (CMA) or less and values of viscosity of about 10 centipoise (CP) or more, when 1 wt.% in water with a salinity of up to approximately 20 pounds (lbs) per 1000 gallons (gals) of water containing organic and/or inorganic salts. Polimernoe, viscoelastic surfactant(a) is selected from the group of cationic surfactants, zwitter-ionic surfactants, amphoteric surfactants, anionic surfactants, and combinations thereof. Polimernoe viscoelastic surface and the active substance(a) is viscoelastic in water even at high salinity, and up to 350F.

Under these and other objectives of the present invention describes another method of oil production from the field. This method includes the stages of (a) the introduction of a frac fluid through the wellbore into the formation under sufficient pressure to cause the gap in the field, and (b) introducing into the field flooding fluid in a location different from the location of the wells. Flooding fluid includes water and a certain amount of one or more polimernyh surfactants sufficient to ensure the values of the surface tension at the interface oil/water approximately 1 CMA or less and a viscosity of approximately 10 SP or more, when 1 wt.% in water at ambient conditions and at high salinity. Polimernoe viscoelastic surfactant(a) is selected from the group of cationic surfactants, zwitter-ionic surfactants, amphoteric surfactants, anionic surfactants, and combinations thereof. Polimernoe viscoelastic surfactant(a) is viscoelastic in ambient conditions and at high salinity and temperatures.

DETAILED description of the INVENTION

Unexpectedly found that by flooding fluid could be added ed is stenny component, allowing to significantly reduce the IFT and significantly increase the viscosity of the injected water during flooding in the tertiary oil extraction method.

In the methods of the present invention flooding fluid comprising one or more polimernyh surfactants, enter, for example, pumped, in the field at high pressure to push or eject out of oil. Used surfactants include polimernye viscoelastic cationic, amphoteric, zwitter-ionic surfactants and anionic surfactants. Polimernye surfactants, forming a viscous liquid, water-based, are preferred, because as a class of surface-active substances are usually compounds with a lower molecular weight than the polymers. Amphoteric surfactants are positively charged and a negatively charged group in a certain pH range (e.g. typically in slightly acidic conditions), only negatively charged group in a certain pH range (e.g. typically in slightly alkaline conditions) and only positively charged group in a different pH range (e.g. typically in moderately acidic conditions.). Zwitter-ionic surface-active washes the VA have in the molecule positively charged group, regardless of pH and negatively charged group at alkaline pH. Cationic surfactants have in the molecule positively charged group, regardless of pH. Anionic surfactants have a negatively charged group, except for the very acidic pH.

Surfactants are present in the flooding fluid in a quantity sufficient to give a flooding fluid before injection into the reservoir or field) interfacial tension (IFT)of approximately 1 CMA or less, preferably about 0.1 CMA or less and most preferably about 0.01 to CMA or less. The IFT value is determined with a tensiometer, based on the method of rotating drops. Surfactants are preferably present in the flooding fluid in a quantity of approximately 0.1-10 wt.% and most preferably about 0.5-6 wt.%, from the total mass of the flooding fluid. The required amount of surfactant varies greatly depending on factors including the type of surfactant, the content of the salt solution in the liquid, and the presence of contamination in the flooding fluid. Surfactants effectively provide the necessary levels of IFT even in flooding liquids having high salinity, then e is te to a concentration of approximately 20 lb/1000 gallons. Salts may be organic or inorganic, including monovalent, divalent and trivalent salts. Inorganic salts, which are commonly found in brackish and salt water, include, inter alia, the chlorides and bromides of potassium, sodium, calcium, magnesium, zinc, iron and ammonium.

Polimernoe viscoelastic surfactant reduces the IFT between the flooding fluid and oil present in the reservoir, and also increases the viscosity of the injected water during flooding. Surfactant causes the formation of oil-water mixtures, or, more preferably, microemulsions, when mixing flooding liquid oil within the field or formation. At the same time, surfactant causes an increase in the viscosity of the flooding fluid, which helps to displace and/or move the oil-water mixture or emulsion through the reservoir to the wellhead, where the specified oil-water mixture or emulsion is taken away or removed. The presence of these surfactants in flooding fluid gives significantly higher viscosity compared with the flooding fluid that does not contain the corresponding viscoelastic surfactants. Higher viscosity in flooding fluid increases the ability of eviction or ejection N. the PTI from the reservoir, that allows you to reduce or completely eliminate the use of conventional polymers, such as FRAMES. The degree of increasing the viscosity varies greatly depending on many factors, including the type and amount of surfactant, the content of the brine in the flooding fluid in the reservoir, the composition and physical characteristics of oil in the reservoir, and the presence of contamination in the flooding fluid. Flooding fluid should include a sufficient amount of surfactant to provide a viscosity of approximately 10 SP or more, more preferably about 25 SP or more, and most preferably approximately 50 JV or more. In practice, can be used flooding fluid with a viscosity of approximately 10-1000 SP.

Surfactants used in the present invention, are viscoelastic. Not wishing to be bound to any theory, I believe that the viscoelasticity is a consequence of the formation of micelles of a different type than the usual spherical micelles formed by the majority of surface-active substances. In the solution of viscoelastic surfactants form a worm-like, rod-like or cylindrical micelles. Viscoelastic surfactants are preferred, as anastaysia sustainable in the process of practical application at high shear stresses, that is, they do not deteriorate irreversibly under the influence of high shear stress. Fluid comprising a viscoelastic surfactant, also show higher permeability through the field than liquids, including viscoelastic surfactant.

The property of viscoelasticity in General, it is well known (S.Gravsholt, Journal of Coll. And Interface Sci., 57(3), 575 (1976); Hoffmann et al., "Influence of Ionic Surfactants on the Viscoelastic Properties of Zwitterionic Surfactant Solutions", Langmuir, 8, 2140-2146 (1992); and Hoffmann et al., The Rheological Behaviour of Different Viscoelastic Surfactant Solutions, Tenside Surf. Det., 31, 289-400, 1994). Means testing is described in detail in the above references, allowing to determine whether the fluid is viscoelastic properties, one test, which, as he discovered, was suitable for determining the viscosity of an aqueous solution, is the mixing of the solution with the formation of a crater under the action of centrifugal force and visual observation, bubbles are formed by mixing, after cessation of mixing. Any presence of bubbles indicates viscoelasticity. Another suitable test is to measure the dynamic modulus of elasticity shear (G') and dynamic mechanical loss shear (G') at a given temperature. If G' > G" at some point or in some range of points below the arr is siteline 10 rad/sec, usually about 0.001 to 10 rad/sec, generally about 0.1-10 rad/sec, at a given temperature, and if G'>10-2PA, preferably 10-1PA, the liquid is usually considered viscoelastic at the same temperature. Rheological measurements of such parameters as G' and G" are discussed more fully in "Rheological Measurements", Encyclopedia of Chemical Technology, vol. 21, p.347-372 (John Wiley & Sons, Inc., N.Y., 1997, 4thed.). The above descriptions are expressly incorporated herein by reference.

Viscoelastic cationic surfactants used in the present invention include compounds selected from (i) certain Quaternary salts and (ii) certain amines, (iii) some aminoxide, and (iv) combinations thereof. Typical cationic surfactants are listed below.

Quaternary salts have the structural formula:

where R1is a hydrophobic residue of alkyl, alkylacrylate, alkoxyalkyl, acylaminoalkyl or acylaminoalkyl and where R1includes approximately 16-22 carbon atoms and may be branched or unbranched, and saturated or unsaturated.

R2and R3represent, independently, (i) aliphatic group, or (ii) the aliphatic group attached to an aromatic or benzyl residue. R2, R3and R5 include from 1 to about 20 atoms. The aliphatic group can be branched or unbranched, and saturated or unsaturated. R2, R3and R5can represent, for example, alkyl, oxyalkyl, polyoxyethyl, alkoxy and alkylaryl. Preferably, R2, R3and R5represent alkyl groups. Most preferably, R2, R3and R5represent a methyl or ethyl group.

X represents a suitable protivoiadie, such as Cl-, Br-and CH3CH3SO4-.

Amines have the following structural formula:

where R1, R2and R3defined above.

The corresponding amines of the above structure include polyoxyethylenated (2-15) cocoalkylamine, polyoxyethylenated (12-18) alkylamines followed tall oil, and polyoxyethylene (2-15) oleyl and artillery.

Examples polimernyh, viscoelastic anionic surfactants used in the present invention, represented by formulas (I)to(V):

(I) ROSO3-

(II) R(OCHR'CHR')mOSO3-

(III) RSO3-

(IV) R(OCHR'CHR')mSO3-

(V) RC6H4-SO3-,

where R represents alkyl, alkenylphenol precalculo or hydroxyalkyl group. R includes approximately 16-24 carbon atoms, and more preferably about 16 to 20 carbon atoms. R may be saturated or unsaturated, branched or non-branched group, a branched alkyl group contains from 1 to about 6 carbon atoms. The appropriate alkyl groups R include dillavou, dolezelova, tetradecanol (ministerului), decodecolor (zetiabuy), octadecanol (railaway), stearyl, Aracinovo group, and derivatives of coconut, tall oil, soy and rapeseed oils. The number alkalinising groups, m varies from 0 to about 35 and more preferably from 0 to about 10.

Examples polimernyh, viscoelastic zwitter-ionic surfactants used in the present invention represented by the formula:

where R1is a hydrophobic residue of alkyl, alkylacrylate, alkoxyalkyl, acylaminoalkyl or acylaminoalkyl, where alkyl represents a group, which includes approximately 12-24, in particular 16-24 carbon atoms and may be branched or unbranched, and saturated or unsaturated. The corresponding long-chain alkyl groups include tetradecanol (ministerului), hexadecimal (zetiabuy), octadecenyl (railaway), about Tatarinova (stearyl), docosanol (Aracinovo) group, and derivatives of tallow, coconut, soybean and rapeseed oils.

Preferred alkyl and alkenylamine groups are alkyl and alkeneamine group, comprising approximately 16-22 carbon atoms. An example of acylaminoalkyl is alkylamides with the above-described alkyl.

R2and R3independently represent an aliphatic chain (i.e. non-aromatic associated with Quaternary nitrogen atom, for example, alkyl, alkenyl, arylalkyl, hydroxyalkyl, carboxyethyl and hydroxyalkyl-polyoxyalkylene, for example hydroxyethyl-polyoxyethylene or hydroxypropyl-polyoxypropylene), comprising about 1-30 carbon atoms, preferably about 1-20 carbon atoms, more preferably approximately 1 to 10 carbon atoms, and most preferably about 1-6 carbon atoms, where the aliphatic group can be branched or unbranched, saturated or unsaturated. Preferred alkyl chains are methyl and ethyl, the preferred arylalkyl is benzyl, and the preferred hydroxyalkyl are hydroxyethyl or hydroxypropyl, and, in addition, the preferred carboxyaniline are acetate and propionate. Preferred hydroxyalkyl-polyoxyalkylene are hydrox the ethyl-polyoxyethylene and hydroxypropyl-polyoxyethylene.

R4represents hydrocarbonyl radical (for example, alkylen) with a chain length of 1-4. Preferred are methylene or ethylene group.

Specific examples of viscoelastic zwitter-ionic surfactants include the following structures:

where R1was defined here above.

Another example is selected viscoelastic zwitter-ionic surfactant is aminoxide. The specified connection has the following formula:

where R1, R2and R3defined above.

Other examples of zwitter-ionic surfactants include dihydroxyethylene tall oil, propionate, aluminophosphates and artillerigatan.

Examples polimernyh viscoelastic amphoteric surfactants include compounds represented by the following formula:

where R1, R2and R4defined above.

Other specific examples of amphoteric viscoelastic surfactants include compounds of the following formulas:

where R1 was defined here above, and X+is an inorganic cation, such as Na+, K+, NH4+associated with a carboxyl group or a hydrogen atom in an acid environment.

Used viscoelastic zwitter-ionic and amphoteric surfactants include compounds described century U.S. patent No. 6831108 B2, which is incorporated herein by reference.

In the methods of the present invention flooding fluid comprising one or more polimernyh viscoelastic surfactants, enter, for example, is injected into the formation or reservoir at high pressure to push or eject out of oil. The point or location of introduction of the flooding fluid is different from the location of the well, i.e. the point at which the oil is extracted or taken from the Deposit. The direction of flooding is usually focused on the area or location on the surface where possible effective extraction or the extraction of oil. Usually the direction of flooding set close to the well or nearby wells or channels in the layers to effectively remove or take away the oil.

Flooding fluid optionally includes one or more components from the group of organic acids, salts of organic acids and inorganic acids and reorgan the ical salts.

Organic acid or its salt contribute to the increased viscosity. Because as flooding fluid injected into the oil field, often used brackish water, flooding fluid may also be some amount of salt.

Used organic acids are usually a sulfonic or carboxylic acid. Anionic counterions of the salts of organic acids are usually sulfonates or carboxylates. Examples of relevant organic compounds include aromatic sulfonates and carboxylates, such as p-toluensulfonate, naphthalenesulfonate, chlorbenzene acid, salicylic acid, phthalic acid, etc. where appropriate counterions are water-soluble. Most preferred are the salicylate, phthalate, p-toluensulfonate, hydroxyethylmethacrylate, for example 5-hydroxy-1-naphthoic acid, 6-hydroxy-1-naphthoic acid, 7-hydroxy-1-naphthoic acid, 1-hydroxy-2-naphthoic acid, preferably 3-hydroxy-2-naphthoic acid, 5-hydroxy-2-naphthoic acid, 7-hydroxy-2-naphthoic acid, and 1,3-dihydroxy-2-naphthoic acid, and 3,4-dichlorobenzoate. Organic acid or its salt may optionally be present in flooding liquids in quantities of approximately 0.1-10 wt.%, more AP is sustained fashion 0.1 to 7 wt.% and most often about 0.1-6 wt.% from the total mass of the flooding fluid.

Used inorganic salts include water-soluble salts of potassium, sodium and ammonium, such as potassium chloride and ammonium chloride. Additionally you can also use calcium chloride, calcium bromide and zinc salts of halogen acids. Inorganic salt is not necessarily present in the flooding fluid in the mass concentration of approximately 0.1-30 wt.%, more about 0.1-10 wt.% and most often about 0.1-8 wt.%. Also, in addition or as a replacement for inorganic salts can be used organic salts such as trimethylammonium hydrochloride and chloride of Tetramethylammonium.

Component of the flooding fluid present in the greatest concentration is water. Typically, water makes up the largest share of the mass of the fluid. Water is usually present in the amount of approximately 50-80% or more by weight of the liquid. Water can be from any source, if the source does not contain any pollutants that are chemically or physically incompatible with other components of the liquid (for example, causing unwanted deposition). Water may not be potable and can be brackish and include salts of such metals as sodium, potassium, calcium, zinc, magnesium, etc. or other compounds, the usual sources of water found in the oil fields or around them.

Optional, for the purpose of regulating the viscosity, flooding fluid can be added to natural or synthetic polymers. Used polymers include, inter alia, guar and guar derivatives, xanthan gum, polyacrylamide (PAM), starch and starch derivatives, cellulose derivatives and polyacrylates.

Flooding fluid (or liquid fracturing) may optionally include a gas, such as air, nitrogen or carbon dioxide, to provide the activated liquid or foam. Can also be used supercritical emulsion of carbon dioxide.

Optional additional reduction of IFT and/or viscosity changes to flooding fluid can be added Sevastopolya, polymer or polimernye surfactants. Sevastopolya surfactants combined with viscoelastic surfactants order effects on IFT and/or viscosity. Used Sevastopolya surfactants can be anionic, cationic, nonionic, zwitter-ionic/amphoteric surfactants and combinations thereof. In the case of Sevastopolya surfactants preferably will be present in limited quantities, that is, approximately 0.5% or less, more preferably in listello of 0.2% or less and most preferably 0.1 wt.% or less, from the total mass of the flooding fluid.

The method of the present invention may optionally be preceded by a stage hydraulic fracturing. When the hydraulic break fluid for fracturing, such as water, is pumped through the borehole and near the surface of the reservoir, when the pressure and flow rate sufficient to overcome the reservoir pressure and the development and/or expansion of the gap(s) in the reservoir. The fracturing fluid optionally includes proppants, such as sand (particle size of 20-40 mesh), bauxite, glass beads, etc. that is suspended in the fluid for fracturing and served in the gap. Proppants prevents the closing of the fracturing when the pressure drops. In tears, filled wedge filler, formed permeable channels through which formation fluid can flow to the well, after which it is extracted or taken.

You must understand that the preceding description is provided solely for the purpose of explanation of the present invention. Experts, skilled in the art may devise various alternatives and modifications, without departing from the invention. Thus, it is assumed that the present invention embraces all such alternatives, modifications and variations that are within the scope of the attached claims.

1. The method of increasing oil production from the field, including
a) the introduction of a flooding fluid into the formation, where the fluid includes:
i) water and
ii) a quantity of one or more polimernyh viscoelastic surfactants sufficient to achieve the flooding fluid values of the surface tension at the interface oil/water approximately 1 CMA or less and a viscosity of approximately 10 SP or more, where one or more polimernyh viscoelastic surfactants selected from the group of one or more amine surfactants having the formula:

where R1is a hydrophobic residue of alkyl, alkylacrylate, alkoxyalkyl, acylaminoalkyl or acylaminoalkyl, and where R1includes approximately 16-22 carbon atoms and may be branched or unbranched, saturated or unsaturated;
where R2and R3independently represent i) aliphatic group, or (ii) the aliphatic group attached to an aromatic or benzyl residue, one or more zwitter-ionic surfactants, one or more amphoteric surfactants, and combinations thereof;
b) extracting oil through the well at a location different from tokiwadai flooding fluid in the field.

2. The method according to claim 1, where the flooding fluid includes about 0.1-20 wt.% one or more polimernyh surface-active substances.

3. The method according to claim 1, where the flooding fluid comprises about 0.5-10 wt.% one or more polimernyh surface-active substances.

4. The method according to claim 1, where the flooding fluid includes approximately 20 pounds of organic and inorganic salts per 1000 gallons of water.

5. The method according to claim 1, where the flooding fluid includes a number of one or more surface-active substances, sufficient to ensure that flooding fluid interfacial tension equal to approximately 0.1 CMA or less.

6. The method according to claim 1, where one or more zwitter-ionic surfactant has the formula:

where R1is a hydrophobic residue of alkyl, alkylacrylate, alkoxyalkyl, acylaminoalkyl or acylaminoalkyl; where alkyl represents a group, which includes approximately 16-24 carbon atoms, which is branched or unbranched, saturated or unsaturated; R2and R3are independently aliphatic chain, comprising about 1-30 carbon atoms, where the aliphatic group is a branched or unbranched, asimenos or unsaturated; and where R4represents hydrocarbonyl radical (for example, alkylen) with a chain length of 1-4.

7. The method according to claim 1, where one or more zwitter-ionic surfactant has the formula:

where R1is a hydrophobic residue of alkyl, alkylacrylate, alkoxyalkyl, acylaminoalkyl or acylaminoalkyl; where alkyl represents a group, which includes approximately 16-24 carbon atoms, which is branched or unbranched, saturated or unsaturated; R2and R3are independently aliphatic chain containing about 1-12 carbon atoms, where the aliphatic group is a branched or unbranched, saturated or unsaturated.

8. The method according to claim 1, where one or more amphoteric surfactants have the formula:

where R1is a hydrophobic residue of alkyl, alkylacrylate, alkoxyalkyl, acylaminoalkyl or acylaminoalkyl; where alkyl represents a group, which includes approximately 16-24 carbon atoms, which is branched or unbranched, saturated or unsaturated; R2represents an aliphatic chain, comprising about 1-30 carbon atoms, where the aliphatic gr is the PAP is a branched or unbranched, saturated or unsaturated; and where R4represents hydrocarbonyl radical with a chain length of 1-4.

9. The method of increasing oil production from the field, including the following stages:
a) the introduction of a frac fluid through the wellbore into the formation under sufficient pressure to form a gap in the field, where the fracturing fluid comprises water;
b) introduction to field flooding fluid in a location different from the location of the wells, where this flooding fluid includes
i) water and
ii) a quantity of one or more polimernyh viscoelastic surfactants sufficient to achieve the flooding fluid values of the surface tension at the interface oil/water approximately 1 CMA or less and a viscosity of approximately 10 SP or more, where one or more surfactants selected from the group of one or more amine surfactants having the formula:

where R1is a hydrophobic residue of alkyl, alkylacrylate, alkoxyalkyl, acylaminoalkyl or acylaminoalkyl, and where R1includes approximately 16-22 carbon atoms and may be branched or unbranched, saturated or unsaturated; R2 and R3independently represent i) aliphatic group, or (ii) the aliphatic group attached to an aromatic or benzyl residue, one or more zwitter-ionic surfactants, one or more amphoteric surfactants, and combinations thereof; and
c) removing the oil through the hole.

10. The method according to claim 9, where the flooding fluid includes about 0.1-20 wt.% one or more polimernyh viscoelastic surfactants.

11. The method according to claim 9, where the flooding fluid comprises about 0.5-10 wt.% one or more polimernyh viscoelastic surfactants.

12. The method according to claim 9, where the flooding fluid includes a number of one or more surface-active substances, sufficient to provide fluid interfacial tension equal to approximately 0.1 CMA or less.

13. The method according to claim 9, where one or more zwitter-ionic surfactant has the formula:

where R1is a hydrophobic residue of alkyl, alkylacrylate, alkoxyalkyl, acylaminoalkyl or acylaminoalkyl; where alkyl represents a group, which includes approximately 12-24 carbon atoms, which is branched or unbranched, nasyshennaya unsaturated; where R2and R3are independently aliphatic chain, comprising about 1-30 carbon atoms, where the aliphatic group is a branched or unbranched, saturated or unsaturated; and where R4represents hydrocarbonyl radical (such as alkylen) with a chain length of 1-4.

14. The method according to claim 9, where one or more zwitter-ion of the viscoelastic surfactant has the formula:

where R1is a hydrophobic residue of alkyl, alkylacrylate, alkoxyalkyl, acylaminoalkyl or acylaminoalkyl; where alkyl represents a group, which includes approximately 12-24 carbon atoms, which is branched or unbranched, saturated or unsaturated; R2and R3are independently aliphatic chain, comprising about 1-30 carbon atoms, where the aliphatic group is a branched or unbranched, saturated or unsaturated.

15. The method according to claim 9, where one or more amphoteric surfactants have the formula:

where R1is a hydrophobic residue of alkyl, alkylacrylate, alkoxyalkyl, acylaminoalkyl or acylaminoalkyl; where alkyl represents a group that includes PR is approximately 16-24 carbon atoms, which is branched or unbranched, saturated or unsaturated; R2represents an aliphatic chain, comprising about 1-30 carbon atoms, where the aliphatic group is a branched or unbranched, saturated or unsaturated; and where R4represents hydrocarbonyl radical with a chain length of 1-4.

16. The method according to claim 1, further comprising a contact fluid containing a viscoelastic surfactant, with the gas.

17. The method according to clause 16, where the gas is selected from the group comprising nitrogen, carbon dioxide, and combinations thereof.

18. The method according to claim 1, where one or more polimernoe viscoelastic surfactant includes one or more zwitter-ionic surface-active substances.

19. The method according to p, where one or more zwitter-ionic surfactants include one or more surfactants selected from realizapopulation and erucyl-aminopropylation.

20. The method according to claim 19, where one or more zwitter-ionic surfactants include aluminophosphates.

21. The method according to claim 19, where one or more zwitter-ionic surfactants include artillerigatan.

22. The method according to claim 19, where one or more zwitter-ionic surfactants include aluminoferrite the ain and artillerigatan.

23. The method according to claim 9, where one or more zwitter-ionic surfactants include one or more compounds in which R1is alkylamides, and the alkyl part of this alkylamidoamines group selected from the group consisting of hexadecimal, octadecanol, octadecanol and docosanol group.

24. The method of increasing oil production from the field, including the following stages:
an introduction to a flooding fluid into the formation, where the fluid includes:
i) water,
ii) a quantity of one or more polimernyh viscoelastic surfactants sufficient to achieve the flooding fluid values of the surface tension at the interface oil/water approximately 1 CMA or less and a viscosity of approximately 10 SP or more, where one or more polimernyh viscoelastic surfactants selected from the group of one or more cationic surfactants, one or more zwitter-ionic surfactants, one or more anionic surfactants, one or more amphoteric surfactants and combinations thereof; and
iii) carbon dioxide, and flooding liquid is in the form of an emulsion of supercritical carbon dioxide, and
b) extracting oil through wells is inu location other than the point of introduction of the flooding fluid in the field.



 

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FIELD: oil and gas industry.

SUBSTANCE: invention relates to the field of the oil and gas industry and may be used at the final stage of developing massive and bedded-massive accumulations with a cap of large thickness and underlaid with a bottom water actively introducing into a productive part of a reservoir, in particular, to increase a drained area of the bottomhole formation zone - BFZ. The concept of the invention is as follows: the method includes arrangement of a horizontal well, its perforation and formation of cracks with the help of reservoir hydraulic rupturing - RHR, subsequent operation of the horizontal well via cracks of the reservoir rupture. When operating an accumulation with an active bottom water and low oil and gas recovery coefficient in a horizontal well, one or more side shafts are drilled in parallel to the plane of a gas oil of an oil and water contact, where RHR is carried out. At the same time RHR in each interval of the side shaft is carried out from its minimum possible rated value in the farthest section from the horizontal shaft to the maximum possible value in the nearest section. Besides, the maximum rupture pressure is accepted as the value that does not exceed the permissible limit value for breakage of a rock skeleton in the area of this side shaft arrangement. Accumulation operation is carried out with depressions at a reservoir that do not permit tightening of a bottom water.

EFFECT: increased drained area of a productive reservoir BFZ and provision of maximum possible yield of oil or gas from a hydrocarbon accumulation.

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18 cl, 1 ex, 1 tbl, 4 dwg

FIELD: oil and gas production.

SUBSTANCE: method of formation hydraulic breakdown (FHB) consists in descending the tubing casing (TS) into hydraulic breakdown zone, pressurisation of casing string annulus by packer, pumping of gas, breakdown agent under pressure through TS. Note that the gas is supplied together with the breakdown agent that is crude oil. Propping agent is supplied after breakdown agent pumping. Note that the gas is inert and it is pumped at 20-30% of breakdown agent volume at a pressure 8 MPa. As propping agent there used is acid-oil emulsion fluid with adding of inert gas at 20-30% of propping agent volume at a pressure 9 MPa. After that the pumping cycle of breakdown agent with gas and propping agent is repeated 3-6 times. Before development the process fluid with inert gas is pumped into tubing casing at 10 MPa in the volume of 20-30% of total volume equal to 1.5-fold inner volume of tubing casing with the following technological exposure for 2-3 h. Note that breakdown agent and propping agent are pumped by equal portions of total volume in each cycle.

EFFECT: simplification of FHB technological process.

1 dwg

FIELD: oil and gas production.

SUBSTANCE: device is made in the form of implosive chamber. The role of a charge is performed by facing powder pressure generator made from elements of ballistite gun powder, located at the outer surface of implosive chamber casing with the possibility of approaching the wall of casing. There is the possibility of facing powder pressure generator ignition, generating of gaseous combustion products and pressure pulse with destruction - cracking of formation rocks in well bore zone and depressurisation of implosive chamber casing after pressure decrease till hydrostatical level. Note that there is provision of wave process of pressure fluctuations with the values of maximum and minimum pressure and duration providing further development of cracks in formation well bore zone.

EFFECT: possibility to develop pressure generator for oil and gas production intensification on the base of gun powder that is characterised by reduced charge mass and comparable to the existing more powerful samples of generators in efficiency.

2 cl

FIELD: chemistry.

SUBSTANCE: cross-linkable composition contains a water-based liquid, a buffer pH regulator, a cross-linkable organic polymer, a cross-linking agent and a retardant. The cross-linking agent is selected from a group comprising an organic titanate, an organic zirconate or combination thereof. The retardant is hydroxyalkylaminocarboxylic acid. The cross-linkable organic polymer is selected from a group comprising soluble polysaccharides, polyacrylamides and polymethacrylamides.

EFFECT: cross-linkable composition enables to control the rate of cross-linking and can be used in a wide pH range, in a range of different cross-linking rates using the same composition.

15 cl, 4 tbl, 8 ex

FIELD: oil and gas industry.

SUBSTANCE: well treatment method involves introduction to the well of treatment liquid containing polymer, binder, organic peroxide, soluble amine connection and functional dilution retarder, where soluble amine connection has chemical structure R3R4N((CR5R6)2-NR7)n-R8, in which n is equal to 2 to 8 and in which R3, R4, R5, R6, R7 and R8 are chosen independently from each other from hydrogen, alkyl, hydroxyalkyl and their combinations, where mass ratio of soluble amine to organic peroxide is approximately 1:1 to approximately 20:1; and treatment liquid dilution. Invention has been developed in dependent claims.

EFFECT: increasing monitoring efficiency of viscosity reduction.

16 cl, 15 ex, 15 dwg

FIELD: oil and gas industry.

SUBSTANCE: method includes isolation of a producing interval with a packer installed above the producing interval, but below the dynamic level in the well, injection of a fluid into the area under the packet via a tubing string, development of multiple hydraulic fractures in the bed. At the same time the fluid is injected with different intensity, its specified characteristics and account of hydraulic fracturing channel walls elasticity properties to ensure the possibility to develop pressure surges - hydraulic shocks in hydraulic fracturing channels at the specified distance from the well bore and increasing depth and/or height of these channels or formation of secondary hydraulic fractures in these channels.

EFFECT: higher efficiency of the method due to well productivity growth at low capacities of the used equipment of bed hydraulic fracturing and increased efficiency of perforation channels.

1 ex

FIELD: chemistry.

SUBSTANCE: liquid composition contains the following: suspension on oil basis, which includes base oil, organophilic clay, polar activating agent, wetting agent, and composition improving the operability in winter conditions, which contains one or many composite monoesters of polyols and/or composite diesters of polyols. Composition is meant for hydraulic fracturing of underground formation, removal of combined wafer from productive underground formation. Hydraulic fracturing method of underground formation involves pumping to the formation under the pressure which is enough for fracturing, liquid for fracturing, which contains propping agent and suspension on oil base, which includes base oil, organophilic clay, polar activating agent, wetting agent and the above composition, or according to the other version - fracturing liquid containing the above suspension, and pumping to the formation subjected to fracturing under pressure which is enough for protection of cracks against joining of carrying liquid with propping agent. Production method involves circulation and/or pumping to production well of the liquid including the above suspension.

EFFECT: improving operability in winter conditions.

25 cl, 18 tbl, 3 ex, 4 dwg

FIELD: oil and gas industry.

SUBSTANCE: device consists of the following: casing with longitudinal axis and through channel; and movable element located in the casing and provided with a through channel and with fluid medium supply hole; J-slot and projection located in J-slot, which guide the movement of movable element relative to the casing; at that, J-slot is located so that it can be rotated between casing and movable element; element with slots along the axis and the second projection located in the element with slots along the axis in order to prevent the rotation of movable element relative to the axis; at that, with slots along the axis between the casing and movable element; locking mechanism located between J-slot and element with slots along the axis; at that, locking mechanism is located between the casing and movable element; at that, movable element is made so that it can move between the first stop position and the second stop position relative to the casing and along the axis; at that, fluid medium supply hole is hydraulically connected to the through channel of the casing and through channel of movable element in order to create fluid medium stream to the well shaft in the first and the second stop positions equally spaced along the axis. The following operations are performed according to the method: lowering of the tool column containing the above device; installation of fluid medium supply hole in the first working place of the well shaft; fixation of the tool column in the well shaft; pumping of fluid medium of underground repair of the well shaft through the tool column to the fluid medium supply hole in the first working place; movement of fluid medium hole relative to the fixed tool column along the axis to the second working place of the well shaft and pumping of fluid medium of underground repair of the well shaft to the second working place equally spaced along the axis.

EFFECT: higher operating reliability of the device and efficiency of the method.

22 cl, 19 dwg

FIELD: oil and gas industry.

SUBSTANCE: methods involving the use of composition for slow increase in adhesive ability, which includes water agent for increasing the adhesive ability and activating agent of slow separation of the acid which is used for stabilisation of particles and minimisation of particle migration inside underground formation. Invention has been developed in dependent claims.

EFFECT: improvement of operating flexibility and controllability of operations and mechanical elasticity of stabilised masses.

20 cl, 1 ex

FIELD: oil and gas production.

SUBSTANCE: method of bottom-hole zone treatment of low-permeable terrigenous formation according to the first version consists in flushing of killed well, sequential pumping of methanol, 18-20% solution of hydrochloric acid for acid bath installation, then the well is repeatedly pumped by 18-20% solution of hydrochloric acid and buffer-gas condensate, acid composition is squeezed into bottom-hole zone of formation by inert gas, then mud acid solution is pumped, gas influx from formation is caused and then reaction products are removed together with gas flow, the well is treated through flare line with removal of reaction products till it reaches design conditions and then the well is placed under production. Method of bottom-hole zone treatment of low-permeable terrigenous formation according to the second version consists in sequential pumping of methanol, 18-20% solution of hydrochloric acid and buffer-gas condensate into non-killed well through tubing casing, acid composition is squeezed into bottom-hole zone of formation by inert gas, then mud acid solution is pumped, gas influx from formation is caused and then reaction products are removed together with gas flow, the well is treated through flare line with removal of reaction products till it reaches design conditions and then the well is placed under production.

EFFECT: recovery of gas-hydro-dynamic connection of well with low-permeable and highly colmataged terrigenous productive formation in condition of abnormally low formation pressure.

2 cl

FIELD: oil and gas production.

SUBSTANCE: method of formation face zone development consists in pumping the gas-generating and acid-based reagents, where gas-generating reagent is the compound that includes, wt %: urea 28.4-38.4, sodium nitrite 18.2-27.6, water - the rest, and acid-based reagent is the compound that includes, wt %: inorganic acid 5.2-60.9, surface acting agent 2.4-3.5, ferrum inhibitor 1.4-2.3, flotation agent 7.0-11.4, water - the rest. Note that the proportion of gas-generating and acid-based reagents amounts 1:(1-3), after pumping of the reagents they are held.

EFFECT: increase of injection capacity of intake well and influx to the producing wells, start of development of leak-proof zones not covered by influence.

3 cl, 2 tbl, 2 ex, 1 dwg

FIELD: oil and gas industry.

SUBSTANCE: method for control of flooding area of oil formations includes oil extraction through production wells and pumping of margins of working agent and silicate in water phase with varying concentration of components trough injection wells. At that watering out of produced oil, capacity of injection wells, allowable pumping pressure and minimal pumping pressure are additionally checked. Pumping is started from injection wells of high capacity, connected hydrodynamicly to highly watered out production wells. At least one injection well is stopped till formation pressure is decreased by 6-24% from formation pressure in area of injection well. Pumping of working agent is started from composition of high-viscosity in quantity not less than 0.5 m3 per 1 m of productive formation with high capacity under pumping pressure exceeding minimal pumping pressure not more than by 20%, at which well accepts. Then margins of water solution of alkaline silicate and polymer are pumped in succession or jointly. Solution of alkaline silicate is used in quantity 0.1-15.0 wt %, and polymer is used in quantity 0.001-3.0 wt %, the other part of solution is water.

EFFECT: increasing oil recovery from formations.

4 cl, 3 ex

FIELD: oil and gas industry.

SUBSTANCE: method includes stages at which cloudy treating fluid with primary microbial population is provided. The fluid is placed in self-contained road mobile manifold of treatment by ultra-violet, which contains source of ultra-violet. Cloudy treating fluid is treated using source of ultra-violet in the presence of weakening reagent to form irradiated treating fluid. Then irradiated treating fluid is supplied to mixing system. Mobile system of treating fluid treatment by ultra-violet contains inlet device, source of treating ultra-violet, chamber for treatment by ultra-violet, weakening reagent, outlet device. At that system of treating fluid treatment by ultra-violet is transported using self-contained road mobile platform.

EFFECT: increasing efficiency of treating fluids disinfection.

12 cl, 2 tbl, 8 dwg

FIELD: oil and gas industry.

SUBSTANCE: well treatment method involves introduction to the well of treatment liquid containing polymer, binder, organic peroxide, soluble amine connection and functional dilution retarder, where soluble amine connection has chemical structure R3R4N((CR5R6)2-NR7)n-R8, in which n is equal to 2 to 8 and in which R3, R4, R5, R6, R7 and R8 are chosen independently from each other from hydrogen, alkyl, hydroxyalkyl and their combinations, where mass ratio of soluble amine to organic peroxide is approximately 1:1 to approximately 20:1; and treatment liquid dilution. Invention has been developed in dependent claims.

EFFECT: increasing monitoring efficiency of viscosity reduction.

16 cl, 15 ex, 15 dwg

FIELD: process engineering.

SUBSTANCE: invention relates to underground processing of formations. Proposed method comprises preparing fluid for processing formation containing water and copolymer reducing friction consisting of acrylamide in amount of 80 wt % to 90 wt % and acrylic acid in amount of 10 wt % to 20 wt %, and feeding it into underground formation. It comprises also preparing copolymer oil emulsion containing water, fluid non-miscible with water and aforesaid copolymer, combining emulsion with additional water for producing water fluid for formation processing, inverting emulsion so that said copolymer is released into water fluid to be forced into underground formation. proposed method comprises preparing copolymer oil emulsion containing water, fluid non-miscible with water containing mix of paraffin hydrocarbons and naphthenic hydrocarbons, emulsifier containing diethanolamide of fat acids of tall oil, monooleat of sorbite polyoxyethylene and sorbite monooleat, above specified copolymer and ammonium salt, 4-metoxyphenol and etoxylated alcohol C12-C16, combining said emulsion with additional water, inverting said emulsion so that copolymer reducing friction is forced into formation.

EFFECT: higher efficiency of reducing friction.

23 cl, 1 ex, 3 tbl

FIELD: chemistry.

SUBSTANCE: liquid composition contains the following: suspension on oil basis, which includes base oil, organophilic clay, polar activating agent, wetting agent, and composition improving the operability in winter conditions, which contains one or many composite monoesters of polyols and/or composite diesters of polyols. Composition is meant for hydraulic fracturing of underground formation, removal of combined wafer from productive underground formation. Hydraulic fracturing method of underground formation involves pumping to the formation under the pressure which is enough for fracturing, liquid for fracturing, which contains propping agent and suspension on oil base, which includes base oil, organophilic clay, polar activating agent, wetting agent and the above composition, or according to the other version - fracturing liquid containing the above suspension, and pumping to the formation subjected to fracturing under pressure which is enough for protection of cracks against joining of carrying liquid with propping agent. Production method involves circulation and/or pumping to production well of the liquid including the above suspension.

EFFECT: improving operability in winter conditions.

25 cl, 18 tbl, 3 ex, 4 dwg

FIELD: oil and gas industry.

SUBSTANCE: methods involving the use of composition for slow increase in adhesive ability, which includes water agent for increasing the adhesive ability and activating agent of slow separation of the acid which is used for stabilisation of particles and minimisation of particle migration inside underground formation. Invention has been developed in dependent claims.

EFFECT: improvement of operating flexibility and controllability of operations and mechanical elasticity of stabilised masses.

20 cl, 1 ex

FIELD: oil-and-gas production.

SUBSTANCE: proposed method comprises injection of water solution of biopolymer-silicate composition via injection well into bench and extracting oil via production well. Note that silicate reagent-to-biopolymer ratio equals 1-0.25. Note here that injection is performed by pattern method from multiple-well pump station into group of injection wells at a time in cycles, 3-4 yearly, amount of said solution making 10 vol. % of threshold volume during first year of threshold volume, 15 vol. % during second year, and 20 vol. % of bench water-saturate section during third year.

EFFECT: higher efficiency, lower costs.

1 tbl, 1 ex

FIELD: oil-and-gas production.

SUBSTANCE: proposed fluid to be used in oil fields comprises: 0.001 wt % to 0.5 wt % of surfactant reducing drag and at least one activator of drag reduction selected from the following group: polymer drag reduction activators selected from the group comprising low-molecular water-soluble polymers and copolymers containing at least one aromatic cycle, or their mixes with monomer drag reduction activator. Note here that said fluid allows drag reduction percentage making at least 20%. Proposed method of regulating clay swell in brine-free well shaft comprises: preparing above fluid suspending reduction agent and injecting it into well shaft. Method of processing in-situ in oil filed whereat said suspending reduction agent is prepared, injected into well shaft to reach drag reduction percentage equal to at least 20%. Invention is developed in dependent claims.

EFFECT: improved viscosity and power to suspend solid substances at low surfactant concentrations.

20 cl, 33 ex, 4 tbl, 36 dwg

FIELD: oil and gas production.

SUBSTANCE: invention provides a method of developing oil pool allowing production of oil from water-rich oil reservoir under difficult geological-tectonic conditions in the last development stage. In the method, neutral salt of carbonic acid and acid solution are forced into formation through injecting well with water generated in gas-liquid fringe created in formation. After pumping of neutral salt of carbonic acid, acid solution is pumped by portions alternating with water pumping. Before pumping of acid solution portions beginning by at least second portion, selective insulation of high-permeable formation intervals is performed. Aforesaid neutral salt of carbonic acid utilized is sodium carbonate aqueous solution or aqueous suspension of calcium carbonate and aforesaid acid solution is aqueous hydrochloric acid solution. Selective insulation of high-permeable formation intervals involves use of freshly prepared controllable viscoelastic composition containing water-soluble acrylic polymer, cross-linking agent, thermal stabilizer, surfactant, and water. Summary concentration of acid solution is determined from concentration of neutral salt of carbonic acid on the base of stoichiometric proportions.

EFFECT: increased efficiency of maintaining formation pressure and thereby oil recovery of formation due to leveled displacement front and reduced probability of the rupture of formation rock backbone, and simplified control of phase state of gas-liquid fringe by changing pressure of pumped acid solution portions.

8 cl

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