CN110642739B - PH responsive soilless phase reversible emulsified drilling fluid and preparation and reversion method thereof - Google Patents

PH responsive soilless phase reversible emulsified drilling fluid and preparation and reversion method thereof Download PDF

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CN110642739B
CN110642739B CN201910730496.0A CN201910730496A CN110642739B CN 110642739 B CN110642739 B CN 110642739B CN 201910730496 A CN201910730496 A CN 201910730496A CN 110642739 B CN110642739 B CN 110642739B
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drilling fluid
acid
emulsifier
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CN110642739A (en
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蒋官澄
任妍君
邓正强
贺垠博
杨丽丽
孙金声
白杨
彭春耀
罗绪武
赵利
马光长
伍贤柱
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China University of Petroleum Beijing
Southwest Petroleum University
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Southwest Petroleum University
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    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C233/00—Carboxylic acid amides
    • C07C233/01—Carboxylic acid amides having carbon atoms of carboxamide groups bound to hydrogen atoms or to acyclic carbon atoms
    • C07C233/16—Carboxylic acid amides having carbon atoms of carboxamide groups bound to hydrogen atoms or to acyclic carbon atoms having the nitrogen atom of at least one of the carboxamide groups bound to a carbon atom of a hydrocarbon radical substituted by singly-bound oxygen atoms
    • C07C233/17—Carboxylic acid amides having carbon atoms of carboxamide groups bound to hydrogen atoms or to acyclic carbon atoms having the nitrogen atom of at least one of the carboxamide groups bound to a carbon atom of a hydrocarbon radical substituted by singly-bound oxygen atoms with the substituted hydrocarbon radical bound to the nitrogen atom of the carboxamide group by an acyclic carbon atom
    • C07C233/20—Carboxylic acid amides having carbon atoms of carboxamide groups bound to hydrogen atoms or to acyclic carbon atoms having the nitrogen atom of at least one of the carboxamide groups bound to a carbon atom of a hydrocarbon radical substituted by singly-bound oxygen atoms with the substituted hydrocarbon radical bound to the nitrogen atom of the carboxamide group by an acyclic carbon atom having the carbon atom of the carboxamide group bound to a carbon atom of an acyclic unsaturated carbon skeleton
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C231/00—Preparation of carboxylic acid amides
    • C07C231/02—Preparation of carboxylic acid amides from carboxylic acids or from esters, anhydrides, or halides thereof by reaction with ammonia or amines
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C231/00—Preparation of carboxylic acid amides
    • C07C231/14—Preparation of carboxylic acid amides by formation of carboxamide groups together with reactions not involving the carboxamide groups
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C235/00—Carboxylic acid amides, the carbon skeleton of the acid part being further substituted by oxygen atoms
    • C07C235/42—Carboxylic acid amides, the carbon skeleton of the acid part being further substituted by oxygen atoms having carbon atoms of carboxamide groups bound to carbon atoms of six-membered aromatic rings and singly-bound oxygen atoms bound to the same carbon skeleton
    • C07C235/44—Carboxylic acid amides, the carbon skeleton of the acid part being further substituted by oxygen atoms having carbon atoms of carboxamide groups bound to carbon atoms of six-membered aromatic rings and singly-bound oxygen atoms bound to the same carbon skeleton with carbon atoms of carboxamide groups and singly-bound oxygen atoms bound to carbon atoms of the same non-condensed six-membered aromatic ring
    • C07C235/50—Carboxylic acid amides, the carbon skeleton of the acid part being further substituted by oxygen atoms having carbon atoms of carboxamide groups bound to carbon atoms of six-membered aromatic rings and singly-bound oxygen atoms bound to the same carbon skeleton with carbon atoms of carboxamide groups and singly-bound oxygen atoms bound to carbon atoms of the same non-condensed six-membered aromatic ring having the nitrogen atom of at least one of the carboxamide groups bound to an acyclic carbon atom of a hydrocarbon radical substituted by nitrogen atoms not being part of nitro or nitroso groups
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    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
    • C09K8/02—Well-drilling compositions
    • C09K8/03—Specific additives for general use in well-drilling compositions
    • C09K8/035—Organic additives
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    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
    • C09K8/02—Well-drilling compositions
    • C09K8/04—Aqueous well-drilling compositions
    • C09K8/26—Oil-in-water emulsions
    • C09K8/28—Oil-in-water emulsions containing organic additives
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
    • C09K8/02—Well-drilling compositions
    • C09K8/32—Non-aqueous well-drilling compositions, e.g. oil-based
    • C09K8/36—Water-in-oil emulsions

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  • Chemical Kinetics & Catalysis (AREA)
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Abstract

The invention relates to the technical field of drilling, in particular to a pH-responsive soilless phase reversible emulsified drilling fluid and a preparation and reversion method thereof. The reversible emulsifier contains at least three compounds represented by formula (1). The reversing process of the drilling fluid is induced by acid and alkali, the reversing between a water-in-oil-in-water oil state or a water-in-oil-double continuous emulsification state is carried out, the pH value of the system in the reversing process is kept between 7 and 8, the acidity and the alkalinity are moderate, the corrosivity on a drilling tool is small, and the fluctuation of the pH value in the reversing process is small, so that the stability of the system is facilitated.
Figure DDA0002160406540000011

Description

PH responsive soilless phase reversible emulsified drilling fluid and preparation and reversion method thereof
Technical Field
The invention relates to the technical field of drilling, in particular to a pH-responsive soilless phase reversible emulsified drilling fluid and a preparation and reversion method thereof.
Background
The drilling fluid is the blood of a well, plays the roles of suspending and carrying rock debris, balancing formation pressure, stabilizing a well wall, cooling and lubricating a drill bit and a drilling tool and transmitting hydrodynamic force in the well drilling process, and reduces the influence on an oil-gas reservoir and the ecological environment as far as possible.
Commonly used drilling fluids include primarily water-based drilling fluids and oil-based drilling fluids. The water-based drilling fluid is easy to clean, but easily causes problems of hydration expansion of shale stratum, drill sticking, borehole wall instability and the like, and has poor lubricating property and high temperature resistance. Compared with water-based drilling fluid, the oil-based drilling fluid has remarkable advantages in the aspects of lubrication, blockage prevention, inhibition of hydration and expansion of shale, well wall stabilization, high temperature resistance, pollution resistance and the like, and is an important means for dealing with complex drilling environment and drilling extremely-high oil and gas reservoirs. However, conventional oil-based drilling fluids are not easy to clean, resulting in difficulties in completing and cementing wells, contamination of oil-bearing drill cuttings, and the like.
The reversible drilling fluid is a novel oil-based drilling fluid and has reversible characteristics, namely: the oil-based drilling fluid exists in the form of the oil-based drilling fluid in the drilling process, has the drilling advantage of the oil-based drilling fluid, and can be reversely converted into the water-based drilling fluid through external stimulation induction after drilling, so that the cleaning is convenient; and then the oil-based drilling fluid is converted into the oil-based drilling fluid through external stimulation again, so that the oil-based drilling fluid is convenient to recycle. The reversible drilling fluid combines the advantages of both oil-based drilling fluids and water-based drilling fluids. For example, US5888944 and US6218342 provide a reversible drilling fluid and its reversal method, the drilling fluid uses alkylamine emulsifier as emulsifier, organic soil as tackifier, oil, water, filtrate reducer, weighting agent, etc. are compounded to form W/O type oil-base drilling fluid, which is reversed from W/O type to O/W type water-base drilling fluid by water-soluble acid induction system such as hydrochloric acid, etc., and then is reversed to W/O type oil-base drilling fluid by alkaline matter such as sodium hydroxide, etc.
CN105385423A provides a method for preparing alkylamine emulsifier and a reversible drilling fluid, the drilling fluid adopts alkylamine emulsifier as emulsifier, organic soil as tackifier, lecithin as wetting agent, oxidized asphalt as filtrate reducer, limestone as weighting agent, oil and water are compounded to form W/O type oil-based drilling fluid, the W/O type oil-based drilling fluid and O/W type water-based drilling fluid are reversed by hydrochloric acid and sodium hydroxide induction system, and the fact that the pH value of the system needs to be changed in the reversing process is emphasized
Figure RE-GDA0002284371160000021
CN106833556A provides a preparation method of an alkylamine emulsifier and a reversible drilling fluid, wherein the drilling fluid adopts the alkylamine emulsifier as the emulsifier, organic soil as the tackifier, humic acid as the filtrate reducer, and oil, water, alcohols, choline chloride, calcium oxide and weighting materials are compounded to form the W/O type oil-based drilling fluid, and the reversion method of the system is to change the pH value of the system by hydrochloric acid and sodium hydroxide so as to induce the system to reverse. Liufei and the like adopt organic amine modified nanoparticles as an emulsifier, organic soil as a tackifier, and then are compounded with a filtrate reducer, a wetting agent, barite and the like to prepare the reversible drilling fluid, wherein the drilling fluid can be reversely converted from W/O type oil-based drilling fluid to O/W type water-based drilling fluid through a hydrochloric acid induction system.
It can be seen that in the prior art, the reversible drilling fluid system has more components, contains an emulsifier, a wetting agent, organic soil, a fluid loss additive and the like, and needs the organic soil and the fluid loss additive to respectively play roles in regulating and controlling rheological property and fluid loss property. However, the presence of organic soils can reduce the rate of penetration and compromise the permeability of the reservoir. In order to avoid the adverse effects of organic soils, soil-free phase oil-based drilling fluid systems have been developed in recent years. For example, CN103788934A provides a soil-free phase oil-based drilling fluid, which is composed of oil, water, emulsifier, fluid loss additive, viscosifier, shear strength improver, alkalinity regulator, barite, but which does not have reversible characteristics.
Disclosure of Invention
The invention aims to overcome the defects of low mechanical drilling speed and large damage to reservoir permeability of reversible drilling fluid containing organic soil in the drilling process in the prior art, and provides a pH-responsive soilless phase reversible emulsified drilling fluid and a preparation method and a reversion method thereof.
In one aspect of the present invention, there is provided a reversible emulsifier comprising at least three compounds represented by formula (1),
formula (1)
Figure RE-GDA0002284371160000031
R is selected from saturated or unsaturated alkyl of C8-C22, R 'and R' are each independently selected from H and alkyl of C1-C3; a 'and A' are each independently selected from O and NH; m + n is more than or equal to 1 and less than or equal to 5;
and, the reversible emulsifier excludes the following: the reversible emulsifier is at least three compounds shown in the formula (1) with R being saturated or unsaturated alkyl of C8-C12 and m + n being more than or equal to 3 and less than or equal to 5.
The second aspect of the invention provides an emulsifier composition, which comprises a main emulsifier and a co-emulsifier, wherein the main emulsifier is the reversible emulsifier, and the co-emulsifier is one or more of amide compounds represented by formula (2);
formula (2) R1-CO-N(R2)-(CH2)x-NH-CO-R3；
Wherein, the group-CO-R3From C8 to C20 with or without saturationSaturated fatty acids providing the group-CO-R1Provided by a dibasic acid of C2-C10 or anhydride thereof, R2Selected from saturated or unsaturated alkyl of C1-C30, and x is an integer of 1-6.
In a third aspect the present invention provides the use of the above emulsifier composition as an emulsifier in a reversible drilling fluid.
In a fourth aspect, the present invention provides an additive composition suitable for use in a drilling fluid, the additive composition comprising a shear strength enhancing agent and an emulsifier composition as described above.
In a fifth aspect, the present invention provides a soil-free phase reversible emulsified drilling fluid of the above additive composition.
The invention provides a method for reversing the soil-free phase reversible emulsified drilling fluid, which comprises the following steps: when acid is added, the soil-free phase reversible drilling fluid is converted from a water-in-oil type to an oil-in-water type or a bicontinuous type; when alkali is added, the oil-in-water type or bicontinuous type emulsified drilling fluid is converted into water-in-oil type soilless phase reversal emulsified drilling fluid.
The seventh aspect of the invention provides a method for cleaning a drilling fluid filter cake by using the soil-free phase-reversible emulsified drilling fluid, which comprises the following steps: the drilling fluid filter cake is contacted with acid liquor, so that the soil-free phase reversible drilling fluid is converted from a water-in-oil type to an oil-in-water type or a bicontinuous soil-free phase emulsified drilling fluid, and the effect of cleaning the drilling fluid filter cake is achieved.
The invention provides a method for cleaning oil-containing drill cuttings by using the soil-free phase reversible emulsified drilling fluid, which comprises the following steps: the oily drilling cuttings are contacted with acid liquor, so that the soil-free phase reversible emulsion drilling fluid is changed from a water-in-oil type to an oil-in-water type or a bicontinuous soil-free phase emulsion drilling fluid, and the effect of cleaning the oily drilling cuttings is achieved.
The ninth aspect of the invention provides an application of the soil-free phase reversible emulsified drilling fluid in oil and gas drilling.
By adopting the reversible emulsifier, the obtained soilless phase reversible emulsified drilling fluid is simple in components, does not contain organic soil, has the advantages of both oil-based drilling fluid and water-based drilling fluid besides the reversible characteristic, and is beneficial to improving the drilling speed, protecting a reservoir and reducing the cost.
In addition, the reversion process of the drilling fluid is induced by acid and alkali, the reversion between a water-in-oil-in-water oil state or a water-in-oil-double continuous emulsification state is carried out, the pH value of a system in the reversion process is kept between 7 and 8, the acidity and the alkalinity are moderate, the corrosivity on a drilling tool is small, and meanwhile, the fluctuation of the pH value in the reversion process is small, so that the stability of the system is facilitated. The reversed drilling fluid system (including filter cake and drill cuttings) is easy to dissolve in water and is easy to clean by water.
Drawings
Figure 1 is a comparison of the filter cake before and after acid washing of drilling fluid SY 5.
Figure 2 is a comparison of the sandstone cuttings of drilling fluid SY5 before and after acid washing.
Detailed Description
The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.
In one aspect of the present invention, there is provided a reversible emulsifier comprising at least three compounds represented by formula (1),
formula (1)
Figure RE-GDA0002284371160000051
R is selected from saturated or unsaturated alkyl of C8-C22, R 'and R' are each independently selected from H and alkyl of C1-C3; a 'and A' are each independently selected from O and NH; m + n is more than or equal to 1 and less than or equal to 5;
and, the reversible emulsifier excludes the following: the reversible emulsifier is at least three compounds shown in the formula (1) with R being saturated or unsaturated alkyl of C8-C12 and m + n being more than or equal to 3 and less than or equal to 5.
After the reversible emulsifier is used for drilling fluid, the reversible emulsifier can help the drilling fluid to respond pH to perform conversion between water-in-oil type drilling fluid and oil-in-water type drilling fluid, so that the drilling advantage of oil-based drilling fluid can be utilized, and the advantage of convenience in cleaning of water-based drilling fluid can be utilized.
Wherein R may be selected from the group consisting of C8 saturated alkyl, C8 unsaturated alkyl having at least one carbon-carbon double bond, C10 saturated alkyl, C10 unsaturated alkyl having at least one carbon-carbon double bond, C12 saturated alkyl, C12 unsaturated alkyl having at least one carbon-carbon double bond, C14 saturated alkyl, C14 unsaturated alkyl having at least one carbon-carbon double bond, C16 saturated alkyl, C16 unsaturated alkyl having at least one carbon-carbon double bond, C18 saturated alkyl, C18 unsaturated alkyl having at least one carbon-carbon double bond, C20 saturated alkyl, C20 unsaturated alkyl having at least one carbon-carbon double bond.
n may be selected from 0, 1, 2, 3, 4, 5; m may be selected from 0, 1, 2, 3, 4, 5.
According to the present invention, preferably R is selected from saturated or unsaturated alkyl groups from C8 to C20; a 'and A' are each independently selected from O and NH; m + n is more than or equal to 1 and less than or equal to 5. More preferably, 1. ltoreq. m + n. ltoreq.3.
In a preferred embodiment of the invention, R is selected from the group consisting of saturated or unsaturated alkyl groups of C8 to C18; a 'and A' are each independently selected from O and NH; r' and R "are H, m + n ═ 1 or 2.
In a preferred embodiment of the present invention, the compound represented by formula (1) is selected from at least three of the compounds represented by the following formulae:
formula (1-1): in the formula (1), R is C8 saturated or unsaturated alkyl, m is 1, n is 0;
formula (1-2): in the formula (1), R is C10 saturated or unsaturated alkyl, m is 1, n is 0;
formula (1-3): in the formula (1), R is C12 saturated or unsaturated alkyl, m is 1, n is 0;
formula (1-4): in the formula (1), R is C14 saturated or unsaturated alkyl, m is 1, n is 0;
formula (1-5): in the formula (1), R is C16 saturated or unsaturated alkyl, m is 1, n is 0;
formula (1-6): in the formula (1), R is C18 saturated or unsaturated alkyl, m is 1, n is 0;
formula (1-7): in the formula (1), R is C8 saturated or unsaturated alkyl, and m + n is 2;
formula (1-8): in the formula (1), R is C10 saturated or unsaturated alkyl, and m + n is 2;
formula (1-9): in the formula (1), R is C12 saturated or unsaturated alkyl, and m + n is 2;
formula (1-10): in the formula (1), R is C14 saturated or unsaturated alkyl, and m + n is 2;
formula (1-11): in the formula (1), R is C16 saturated or unsaturated alkyl, and m + n is 2;
formula (1-12): in the formula (1), R is C18 saturated or unsaturated alkyl, and m + n is 2;
formula (1-13): in the formula (1), R is C8 saturated or unsaturated alkyl, and m + n is 3;
formula (1-14): in the formula (1), R is C10 saturated or unsaturated alkyl, and m + n is 3;
formula (1-15): in the formula (1), R is C12 saturated or unsaturated alkyl, and m + n is 3;
formulae (1-16): in the formula (1), R is C14 saturated or unsaturated alkyl, and m + n is 3;
formula (1-17): in the formula (1), R is C16 saturated or unsaturated alkyl, and m + n is 3;
formula (1-18): in the formula (1), R is a saturated or unsaturated alkyl of C18, and m + n is 3.
According to the present invention, the reversible emulsifier can have various combinations.
In a preferred embodiment of the present invention, the reversible emulsifier contains a compound represented by formula (1-10), a compound represented by formula (1-11), and a compound represented by formula (1-12). Preferably, the content of the compound represented by the formula (1-10) is 1-20% by weight, the content of the compound represented by the formula (1-11) is 1-40% by weight, and the content of the compound represented by the formula (1-12) is 30-98% by weight. More preferably, the content of the compound represented by the formula (1-10) is 1-10% by weight, the content of the compound represented by the formula (1-11) is 1-35% by weight, and the content of the compound represented by the formula (1-12) is 50-98% by weight. Still more preferably, the content of the compound represented by the formula (1-10) is 2 to 8% by weight, the content of the compound represented by the formula (1-11) is 10 to 35% by weight, and the content of the compound represented by the formula (1-12) is 50 to 90% by weight. In this embodiment, the reversible emulsifier may further contain a compound represented by formula (1-9). Preferably, the compound represented by the formula (1-9) is contained in an amount of 1-10% by weight, more preferably 1-5% by weight.
In another preferred embodiment of the present invention, the reversible emulsifier comprises a compound represented by formula (1-1), a compound represented by formula (1-2), a compound represented by formula (1-3), a compound represented by formula (1-4), a compound represented by formula (1-5) and a compound represented by formula (1-6). Preferably, the content of the compound represented by the formula (1-1) is 1 to 10% by weight, the content of the compound represented by the formula (1-2) is 1 to 10% by weight, the content of the compound represented by the formula (1-3) is 30 to 60% by weight, the content of the compound represented by the formula (1-4) is 10 to 30% by weight, the content of the compound represented by the formula (1-5) is 2 to 15% by weight, and the content of the compound represented by the formula (1-6) is 5 to 20% by weight. More preferably, the content of the compound represented by the formula (1-1) is 2 to 6% by weight, the content of the compound represented by the formula (1-2) is 4 to 10% by weight, the content of the compound represented by the formula (1-3) is 35 to 55% by weight, the content of the compound represented by the formula (1-4) is 15 to 25% by weight, the content of the compound represented by the formula (1-5) is 5 to 15% by weight, and the content of the compound represented by the formula (1-6) is 5 to 15% by weight.
In another preferred embodiment of the present invention, the reversible emulsifier comprises a compound represented by formula (1-4), a compound represented by formula (1-5), and a compound represented by formula (1-6). Preferably, the content of the compound represented by the formula (1-4) is 1 to 20% by weight, the content of the compound represented by the formula (1-5) is 1 to 40% by weight, and the content of the compound represented by the formula (1-6) is 30 to 98% by weight. More preferably, the content of the compound represented by the formula (1-4) is 1 to 10% by weight, the content of the compound represented by the formula (1-5) is 1 to 35% by weight, and the content of the compound represented by the formula (1-6) is 50 to 98% by weight. Still more preferably, the content of the compound represented by the formula (1-4) is 2 to 8% by weight, the content of the compound represented by the formula (1-5) is 10 to 35% by weight, and the content of the compound represented by the formula (1-6) is 50 to 90% by weight. In this embodiment, the reversible emulsifier may further contain a compound represented by formula (1-3). Preferably, the compound represented by the formula (1-3) is contained in an amount of 1-10% by weight, more preferably 1-5% by weight.
Specific examples of the compound represented by the formula (1-1) may be selected from one or more of the compounds represented by the following formulae:
formula (1-1-1): in the formula (1-1), R is n-octyl or octyl containing one unsaturated carbon-carbon double bond, and R' is H.
Formula (1-1-2): in the formula (1-1), R is n-octyl or octyl containing one unsaturated carbon-carbon double bond, and R' is methyl.
Specific examples of the compound represented by the formula (1-2) may be selected from one or more of the compounds represented by the following formulae:
formula (1-2-1): in the formula (1-2), R is n-decyl or decyl containing one unsaturated carbon-carbon double bond, and R' is H.
Formula (1-2-2): in the formula (1-2), R is n-decyl or decyl containing one unsaturated carbon-carbon double bond, and R' is methyl.
Specific examples of the compound represented by the formula (1-3) may be selected from one or more of the compounds represented by the following formulae:
formula (1-3-1): in the formula (1-3), R is n-dodecyl or dodecyl containing one unsaturated carbon-carbon double bond, and R' is H.
Formula (1-3-2): in the formula (1-3), R is n-dodecyl or dodecyl containing one unsaturated carbon-carbon double bond, and R' is methyl.
Specific examples of the compound represented by the formula (1-4) may be selected from one or more of the compounds represented by the following formulae:
formula (1-4-1): in the formula (1-3), R is n-tetradecyl or tetradecyl containing one unsaturated carbon-carbon double bond, and R' is H.
Formula (1-4-2): in the formula (1-3), R is n-tetradecyl or tetradecyl containing one unsaturated carbon-carbon double bond, and R' is methyl.
Specific examples of the compound represented by the formula (1-5) may be selected from one or more of the compounds represented by the following formulae:
formula (1-5-1): in the formula (1-5), R is n-hexadecyl or hexadecyl containing an unsaturated carbon-carbon double bond, and R' is H.
Formula (1-5-2): in the formula (1-5), R is n-hexadecyl or hexadecyl containing an unsaturated carbon-carbon double bond, and R' is methyl.
Specific examples of the compounds represented by the formulae (1 to 6) may be selected from one or more of the compounds represented by the following formulae:
formula (1-6-1): in the formula (1-6), R is n-octadecyl or octadecyl containing an unsaturated carbon-carbon double bond, and R' is H.
Formula (1-6-2): in the formula (1-6), R is n-octadecyl or octadecyl containing an unsaturated carbon-carbon double bond, and R' is methyl.
Specific examples of the compound represented by the formula (1-7) may be selected from one or more of the compounds represented by the following formulae:
formula (1-7-1): in the formula (1-7), R is n-octyl or octyl containing one unsaturated carbon-carbon double bond, R 'and R' are H, and m ═ n ═ 1.
Formula (1-7-2): in the formula (1-7), R is n-octyl or octyl containing one unsaturated carbon-carbon double bond, R 'and R' are methyl, and m ═ n ═ 1.
Specific examples of the compounds represented by the formulae (1 to 8) may be selected from one or more of the compounds represented by the following formulae:
formula (1-8-1): in the formula (1-8), R is n-decyl group or decyl group containing one unsaturated carbon-carbon double bond, R 'and R' are H, and m ═ n ═ 1.
Formula (1-8-2): in the formula (1-8), R is n-decyl group or decyl group containing one unsaturated carbon-carbon double bond, R 'and R' are methyl groups, and m ═ n ═ 1.
Specific examples of the compounds represented by the formulae (1 to 9) may be selected from one or more of the compounds represented by the following formulae:
formula (1-9-1): in the formula (1-9), R is n-dodecyl or dodecyl containing one unsaturated carbon-carbon double bond, R 'and R' are H, and m ═ n ═ 1.
Formula (1-9-2): in the formula (1-9), R is n-dodecyl or dodecyl containing one unsaturated carbon-carbon double bond, R 'and R' are methyl, and m ═ n ═ 1.
Specific examples of the compounds represented by the formulae (1 to 10) may be selected from one or more of the compounds represented by the following formulae:
formula (1-10-1): in the formula (1-10), R is n-tetradecyl or tetradecyl containing one unsaturated carbon-carbon double bond, R 'and R' are H, and m ═ n ═ 1.
Formula (1-10-2): in the formula (1-10), R is n-tetradecyl or tetradecyl containing one unsaturated carbon-carbon double bond, R 'and R' are methyl, and m ═ n ═ 1.
Specific examples of the compounds represented by the formulae (1 to 11) may be selected from one or more of the compounds represented by the following formulae:
formula (1-11-1): in the formula (1-11), R is n-hexadecyl or hexadecyl containing one unsaturated carbon-carbon double bond, R 'and R' are H, and m ═ n ═ 1.
Formula (1-11-2): in the formula (1-11), R is n-hexadecyl or hexadecyl containing one unsaturated carbon-carbon double bond, R 'and R' are methyl, and m ═ n ═ 1.
Specific examples of the compounds represented by the formulae (1 to 12) may be selected from one or more of the compounds represented by the following formulae:
formula (1-12-1): in the formula (1-12), R is n-octadecyl or octadecyl containing one unsaturated carbon-carbon double bond, R 'and R' are H, and m ═ n ═ 1.
Formula (1-12-2): in the formula (1-12), R is n-octadecyl or octadecyl containing one unsaturated carbon-carbon double bond, R 'and R' are methyl, and m ═ n ═ 1.
Specific examples of the compounds represented by the formulae (1 to 13) may be selected from one or more of the compounds represented by the following formulae:
formula (1-13-1): in the formula (1-13), R is n-octyl or octyl containing one unsaturated carbon-carbon double bond, R 'and R' are H, m is 2, and n is 1.
Formula (1-13-2): in the formula (1-13), R is n-octyl or octyl containing one unsaturated carbon-carbon double bond, R 'and R' are methyl, m is 2, and n is 1.
Specific examples of the compounds represented by the formulae (1 to 14) may be selected from one or more of the compounds represented by the following formulae:
formula (1-14-1): in the formula (1-14), R is n-decyl or decyl containing one unsaturated carbon-carbon double bond, R 'and R' are H, m is 2, and n is 1.
Formula (1-14-2): in the formula (1-14), R is n-decyl or decyl containing one unsaturated carbon-carbon double bond, R 'and R' are methyl, m is 2, and n is 1.
Specific examples of the compounds represented by the formulae (1 to 15) may be selected from one or more of the compounds represented by the following formulae:
formula (1-15-1): in the formula (1-15), R is n-dodecyl or dodecyl containing one unsaturated carbon-carbon double bond, R 'and R' are H, m is 2, and n is 1.
Formula (1-15-2): in the formula (1-15), R is n-dodecyl or dodecyl containing one unsaturated carbon-carbon double bond, R 'and R' are methyl, m is 2, and n is 1.
Specific examples of the compounds represented by the formulae (1 to 16) may be selected from one or more of the compounds represented by the following formulae:
formula (1-16-1): in the formula (1-16), R is n-tetradecyl or tetradecyl containing one unsaturated carbon-carbon double bond, R 'and R' are H, m is 2, and n is 1.
Formula (1-16-2): in the formula (1-16), R is n-tetradecyl or tetradecyl containing one unsaturated carbon-carbon double bond, R 'and R' are methyl, m is 2, and n is 1.
Specific examples of the compounds represented by the formulae (1 to 17) may be selected from one or more of the compounds represented by the following formulae:
formula (1-17-1): in the formula (1-17), R is n-hexadecyl or hexadecyl containing one unsaturated carbon-carbon double bond, R 'and R' are H, m is 2, and n is 1.
Formula (1-17-2): in the formula (1-17), R is n-hexadecyl, R 'and R' are methyl, m is 2, and n is 1.
Specific examples of the compounds represented by the formulae (1 to 18) may be selected from one or more of the compounds represented by the following formulae:
formula (1-18-1): in the formula (1-18), R is n-octadecyl or octadecyl containing one unsaturated carbon-carbon double bond, R 'and R' are H, m is 2, and n is 1.
Formula (1-18-2): in the formula (1-18), R is n-octadecyl or octadecyl containing one unsaturated carbon-carbon double bond, R 'and R' are methyl, m is 2, and n is 1.
The second aspect of the invention provides an emulsifier composition, which comprises a main emulsifier and a co-emulsifier, wherein the main emulsifier is the reversible emulsifier, and the co-emulsifier is one or more of amide compounds represented by formula (2);
formula (2) R1-CO-N(R2)-(CH2)x-NH-CO-R3；
Wherein, the group-CO-R3Provided by a saturated or unsaturated fatty acid of C8-C20, the group-CO-R1Provided by a dibasic acid of C2-C10 or anhydride thereof, R2Selected from saturated or unsaturated alkyl of C1-C30, and x is an integer of 1-6.
In order to better exploit the CO-emulsifier and CO-emulsifier combinations of the invention, the group-CO-R is preferably3Provided by a saturated or unsaturated fatty acid of C10-C18, the group-CO-R1Provided by a dibasic acid of C2-C6 or anhydride thereof, R2Selected from saturated or unsaturated alkyl of C1-C30, and x is an integer of 1-3. More preferably, the group-CO-R3Provided by saturated fatty acids of C10-C18 or unsaturated fatty acids of C10-C18 containing at least one carbon-carbon double bond, R2Selected from saturated alkyl of C8-C18 or alkyl of C8-C18 containing at least one carbon-carbon double bond. Even more preferably, the group-CO-R3Supplied by tall oil fatty acid, oleic acid or linoleic acid; group-CO-R1Is provided by oxalic acid, malonic acid, maleic acid or maleic acid glycoside.
It is understood that the group-CO-R3The acid described above provides, i.e., removes a molecule of water from the acid and amine group to form an amidated group, the residue remaining from the acid. group-CO-R1The diacid or anhydride thereof described above is provided as the residue remaining when one carboxylic acid group of the diacid or anhydride thereof is de-coupled from an amine group to form an amidated group.
According to the present invention, in order to enable the primary emulsifier and the secondary emulsifier to be better matched, the weight ratio of the primary emulsifier to the secondary emulsifier is preferably 100: 2-80, preferably 100: 10-50, more preferably 100: 25-40.
According to the present invention, the second emulsifier is preferably prepared by a preparation method comprising:
(1) carrying out first amidation reaction on the compound shown in the formula (2-1) and the compound shown in the formula (2-2) under first amidation reaction conditions to obtain a first amidation reaction product;
(2) under the condition of second amidation reaction, carrying out second amidation reaction on the first amidation reaction product and the compound shown in the formula (2-3) to obtain a second amidation reaction product, namely a second emulsifier;
formula (2-1) R3-COOH；
Formula (2-2) HN (R)2)-(CH2)x-NH2；
Formula (2-3) R1-COOH or an anhydride thereof,
wherein the groups referred to in the formula (2-1), the formula (2-2) and the formula (2-3) are as described above.
In a preferred embodiment of the present invention, the compound represented by formula (2-1) is one or more of tall oil fatty acid, oleic acid and linoleic acid; the compound shown in the formula (2-2) is one or more of N-cocoyl-1, 3-propylene diamine, N-tallow-1, 3-propylene diamine and N-oleyl-1, 3-propylene diamine; the compound shown in the formula (2-3) is one or more of oxalic acid, malonic acid, maleic acid and maleic acid glycoside.
In order to allow the compound represented by the formula (2-1), the compound represented by the formula (2-2) and the compound represented by the formula (2-3) to react more smoothly to prepare a co-emulsifier, it is preferable that the compound represented by the formula (2-1), the compound represented by the formula (2-2) and the compound represented by the formula (2-3) are used in a molar ratio of 1: 0.8-1.5: 0.8 to 1.5, preferably 1: 0.9-1.2: 0.9-1.2.
Preferably, the conditions of the first amidation reaction include: the temperature is 140 ℃ and 180 ℃, and the time is 10-24 h.
Preferably, the conditions of the second amidation reaction include: the temperature is 80-120 ℃ and the time is 2-5 h.
In a third aspect the present invention provides the use of the above emulsifier composition as an emulsifier in a reversible drilling fluid.
In a fourth aspect, the present invention provides an additive composition suitable for use in a drilling fluid, the additive composition comprising a shear strength enhancing agent and an emulsifier composition as described above.
According to the invention, the emulsifier composition can better cooperate with a preferred cutting agent which is a dimer acid-organic amine copolymer comprising structural units derived from a dimer acid, structural units derived from an alkylamine and structural units derived from an aromatic amine, wherein the dimer acid is a dimer of oleic acid and linoleic acid, the alkylamine is one or more of C10-C20 alkyl primary amines, and the aromatic amine is one or more of aniline and aniline mono-or multi-substituted on the benzene ring by C1-C3 alkyl. Specifically, the shear-promoting agent is a dimer acid-organic amine copolymer provided in CN 104893691A.
Preferably, the weight ratio of the emulsifier composition to the shear strength improver is 100: 2-80, preferably 100: 10-50, more preferably 100: 20-40.
In a fifth aspect, the present invention provides a soil-free phase reversible drilling fluid of the above additive composition.
According to the invention, the soil-free phase reversible drilling fluid contains an aqueous phase and an oil phase so as to be capable of reversible conversion, wherein the volume ratio of the oil phase to the aqueous phase can be 60:40-40: 60. The oil phase may be provided by an oil phase conventionally employed in the art, and may be, for example, diesel and white oils (e.g., 3# white oil (having a flash point of 220 ℃ C., a kinematic viscosity of 3mm at 40 ℃ C.) as examples20.85 specific gravity/s), 5# white oil (flash point 220 deg.C, kinematic viscosity at 40 deg.C 3.5mm2/s, specific gravity of 0.85). The aqueous phase may be a salt-containing water, e.g. containing 20-30 wt.% CaCl2Brine.
According to the invention, the content of the additive composition may vary within a certain range, preferably the content of the emulsifier composition is 3-6 wt% and the content of the shear-enhancing agent is 0.5-1.2 wt% relative to the total weight of the soilless phase reversible drilling fluid without weighting agent.
According to the invention, the soil-free phase reversible drilling fluid can also contain a weighting agent to adjust the density of the drilling fluid, for example, the weighting agent can be barite (for example, barite with barium sulfate content of more than 90 WT%), organic salt (one or more of weight-1, weight-2 (potassium formate as active ingredient), weight-3, organic sodium salt GD-WT) and the like) to make the drilling fluid obtain the required density, for example, 1-2g/cm3。
The sixth aspect of the present invention provides a method for reversing the above soil-free phase-reversible drilling fluid, including: when acid is added, the soil-free phase reversible emulsion drilling fluid is changed from a water-in-oil type to an oil-in-water type or a bicontinuous type; when alkali is added, the oil-in-water type or bicontinuous type soilless phase emulsion drilling fluid is converted into water-in-oil type soilless phase inverse emulsion drilling fluid.
Wherein, the addition amount of the acid is preferably 40 to 70 percent of the mol content of the reversible emulsifier, and the addition amount of the alkali is preferably 40 to 70 percent of the mol content of the reversible emulsifier.
The acid may be a conventional organic acid or inorganic acid, and may be, for example, acetic acid or hydrochloric acid. The base may be a conventional organic base or inorganic base, and may be, for example, sodium hydroxide or the like.
The seventh aspect of the invention provides a method for cleaning a drilling fluid filter cake by using the soil-free phase-reversible emulsified drilling fluid, which comprises the following steps: the drilling fluid filter cake is contacted with acid liquor, so that the soil-free phase reversible emulsified drilling fluid is converted from a water-in-oil type to an oil-in-water type or a bicontinuous soil-free phase emulsified drilling fluid, and the effect of cleaning the drilling fluid filter cake is achieved.
The soil-free phase reversible water-in-oil drilling fluid can be used for easily cleaning a drilling fluid filter cake, namely, the soil-free phase reversible emulsified water-in-oil drilling fluid is reversed under the action of acid by using acid liquor, so that the oil-in-water type or double-continuous soil-free phase emulsified drilling fluid can be formed, and the drilling fluid filter cake can be cleaned by washing with water.
The invention provides a method for cleaning oil-containing drill cuttings by using the soil-free phase reversible emulsified drilling fluid, which comprises the following steps: the oily drilling cuttings are contacted with acid liquor, so that the soil-free phase reversible emulsion drilling fluid is changed from a water-in-oil type to an oil-in-water type or a bicontinuous soil-free phase emulsion drilling fluid, and the effect of cleaning the oily drilling cuttings is achieved.
The soil-free phase reversible emulsified water-in-oil drilling fluid can be used for easily cleaning oil-containing drilling cuttings, namely, the soil-free phase reversible emulsified water-in-oil drilling fluid is reversed under the action of acid by using acid liquor, so that the oil-in-water type or double-continuous soil-free phase emulsified drilling fluid can be formed, and the oil-containing drilling cuttings can be cleaned by water washing.
The ninth aspect of the invention provides an application of the soil-free phase reversible emulsified drilling fluid in oil and gas drilling.
The reversing process of the drilling fluid is induced by acid and alkali, the reversing between a water-in-oil-in-water oil state or a water-in-oil-double continuous emulsification state is carried out, the pH value of the system in the reversing process is kept between 7 and 8, the acidity and the alkalinity are moderate, the corrosivity on a drilling tool is small, the fluctuation of the pH value in the reversing process is small, and the stability of the system is facilitated.
The present invention will be described in detail below by way of examples.
Preparation of cutting agent example 1
(1) Adding dimer acid (Pripol 1013 of Shanghai and Dewar chemical Co., Ltd., the same below), dodecyl primary amine and aniline at a molar ratio of 1: 0.5 into a reaction vessel, and stirring at 120 + -2 deg.C for 30min to obtain a monomer mixture;
(2) concentrated sulfuric acid (98 wt% in terms of the amount of 0.5 wt% based on the amount of the monomer mixture) was added dropwise to the above monomer mixture (after about 2 min), and the mixture was reacted at 160. + -.5 ℃ for 2 hours in a condensation-drainage apparatus to obtain a dimer acid-organic amine copolymer having a weight-average molecular weight of 6500g/mol and an absolute viscosity of 125000 cp.
To the dimer acid-organic amine copolymer was added tall oil (available from jinan jinquan chemical co., ltd., No. F1, the same below) as a diluent to dilute the dimer acid-organic amine copolymer to a concentration of 50% by weight, to obtain a shear improver T1, which was an orange liquid.
Coemulsifier preparation example 1
This preparation is intended to illustrate the preparation of the coemulsifier of the invention.
(1) Tall oil fatty acid (0.136mol) was added dropwise to liquid N-tallow-1, 3-propylenediamine (0.124mol) under reflux at 60 ℃ for about 30 min. Then, heating to 165 ℃ and continuously reacting for 16 h;
(2) and (2) cooling the reaction system to 100 ℃, continuously dropwise adding the previously melted maleic acid glycoside (0.135mol) into the reaction system in the step (1) under reflux stirring, and finishing the addition for 1 h. The mixture is kept at 100 ℃ and stirred under reflux for 3 hours to react, thus obtaining the coemulsifier A1.
Drilling fluid preparation examples 1 to 17
The drilling fluid formula comprises: the volume ratio is 50: 50 # white 5 oil (from British chemical Co., Guangdong) and 25 wt.% CaCl2Brine, 4 wt% of a primary emulsifier (see Table 1 for specific compositions, available from Ethox Chemicals, LLC (Greenville, South Carolina)), 2 wt% of a secondary emulsifier A1, 0.5 wt% of a shear strength agent T1 (the content of each additive is based on the total weight of the drilling fluid without the addition of a weighting agent), and weighting agent barite to adjust the density of the drilling fluid to 1.10g/cm3(ii) a Thereby obtaining the corresponding water-in-oil drilling fluid Y1-Y17; and adding acid and alkali to test whether the drilling fluids are reversible, if the water-in-oil drilling fluid is converted into oil-in-water or bicontinuous drilling fluid after the acid is added, and the alkali is added to convert into water-in-oil drilling fluid, the reversible is shown; if the conversion from a water-in-oil drilling fluid to an oil-in-water drilling fluid or a bicontinuous drilling fluid is not achieved after the addition of the acid, or if the conversion to an oil-in-water drilling fluid is achieved after the addition of the base, the conversion to a water-in-oil drilling fluid is not achieved, the inversion is indicated, and the results are shown in Table 1.
Comparative drilling fluids 1-5
According to the same formula of the preparation examples of the drilling fluid, except that the main emulsifier has different compositions, which are shown in table 1, the corresponding water-in-oil drilling fluid DY1-DY5 is obtained; the results of the reversion tests with acid and base addition are shown in table 1.
TABLE 1
Figure RE-GDA0002284371160000181
Note: the main emulsifier composition is compounds corresponding to formula (1), A 'and A' of the compounds are O, R 'and R' are H, m and n of the compounds shown in formula (1) in the same row meet the definition of polymerization degree m and n value of the ethoxylene in the same row of the table; the alkyl chains of R are all alkyl chains containing one unsaturated bond; the composition distribution of the main emulsifier refers to the weight percentage of the compound represented by the formula (1) below each R alkyl chain in each list in the main emulsifier component.
The test results in Table 1 show that the water-in-oil drilling fluid (No. Y1-Y17) adopting the main emulsifier can be converted into an oil-in-water drilling fluid when acid is added, and then alkali is added, so that the oil-in-water drilling fluid can be converted from the oil-in-water drilling fluid, and the reversible performance of controllable acid and alkali is realized.
Test example 2
The HLB value of the primary emulsifier used in the above drilling fluid preparations 1 to 17 was measured, and the demulsification voltage (ES) value of the drilling fluid obtained in the above drilling fluid preparations 1 to 17 was measured, and the results are shown in table 2, in which:
the HLB value is calculated by the following method:
HLB＝20×MH/(MH+ML)，
MH-molecular weight of the hydrophilic group; mL-the molecular weight of the lipophilic group; HLB-the clear water lipophilic balance of the surfactant.
The breaking voltage (ES) is measured by an electrical stability instrument according to the method specified in petrochemical industry Standard SH/T0549-1994, in V.
TABLE 2
Figure RE-GDA0002284371160000191
Figure RE-GDA0002284371160000201
As can be seen from the data in Table 2, the drilling fluid of the present invention added with the emulsifier composition of the present invention has higher emulsion stability, and especially, the multi-chain distribution of the hydrophobic end is more favorable for the stability of the water-in-oil emulsion than the single-chain distribution of the hydrophobic end, and the long carbon chain ratio in the multi-chain distribution needs to be dominant.
Test example 3
According to the formula of the drilling fluid Y1, the difference is as follows:
drilling fluid SY 1: the drilling fluid is adjusted to have the density of 1.2g/cm by adjusting the content of the main emulsifier to be 4 weight percent and not containing the auxiliary emulsifier and the shear-promoting agent and the weighting agent barite3；
Drilling fluid SY 2: the drilling fluid is adjusted to have the density of 1.35g/cm by adjusting the content of the main emulsifier to be 4 weight percent and not containing the auxiliary emulsifier and the shear-promoting agent and the weighting agent barite3；
Drilling fluid SY 3: the drilling fluid is adjusted to have the density of 1.65g/cm by adjusting the content of the main emulsifier to be 4 weight percent and not containing the auxiliary emulsifier and the shear strength improving agent and the weighting agent barite3；
Drilling fluid SY 4: the drilling fluid is adjusted to have the density of 1.35g/cm by adjusting the content of the primary emulsifier to be 4.5 weight percent and not containing the auxiliary emulsifier and the shear strength improving agent and the weighting agent barite3；
Drilling fluid SY 5: the weighting agent barite adjusts the density of the drilling fluid to be 1.2g/cm3；
Drilling fluid SY 6: the weighting agent barite adjusts the density of the drilling fluid to be 1.35g/cm3；
Drilling fluid SY 7: the weighting agent barite adjusts the density of the drilling fluid to be 1.65g/cm3；
Drilling fluid SY 8: the weighting agent barite adjusts the density of the drilling fluid to be 1.85g/cm3。
Respectively measuring the rheological property and the fluid loss property of the drilling fluid, specifically measuring the Apparent Viscosity (AV), the Plastic Viscosity (PV), the dynamic shear force (YP), the dynamic-plastic ratio (YP/PV), the GEL GEL strength (G10 '/10'), the medium-pressure fluid loss (API), the high-pressure fluid loss (HTHP) and the demulsification voltage (ES) of the obtained drilling fluid before aging and after aging at 120 ℃ for 16h to room temperature; the results are shown in table 3, in which:
the Apparent Viscosity (AV) is measured using a van-type six-speed viscometer according to the method specified in the national standard GB/T29170-2012, in mPas,
Figure RE-GDA0002284371160000211
the Plastic Viscosity (PV) is measured using a van-type six-speed viscometer according to the method specified in the national standard GB/T29170-2012, in mPas, PV ═ θ600-θ300。
Dynamic shear force (YP) was measured using a van six-speed viscometer according to the method specified in national standard GB/T29170-2012, YP 0.511 × (2 × Φ 300- Φ 600) in Pa.
Dynamic plastic ratio YP/PV.
GEL strength (G10 "/10') was measured according to the method specified in the national standard GB/T29170-2012, in Pa/Pa, according to a van-type six-speed viscometer.
HTHP refers to high-temperature and high-pressure filtration loss, and is measured by a high-temperature and high-pressure filtration loss instrument according to a method specified in the national standard GB/T29170-2012, and has a unit of mL.
The breaking voltage (ES) is measured by an electrical stability instrument according to the method specified in petrochemical industry Standard SH/T0549-1994, in V.
TABLE 3
Figure RE-GDA0002284371160000212
Figure RE-GDA0002284371160000221
As can be seen from the results in table 3, the drilling fluid system with the addition of the reversible emulsifier of the present invention can achieve superior emulsion stability, rheology and fluid loss over a wide range of densities; in particular, the drilling fluid added with the emulsifier composition can obtain excellent high temperature resistance.
Test example 4
Adding 50 weight percent acetic acid aqueous solution into the drilling fluid Y150 g, then adding sodium hydroxide, measuring the demulsification voltage, the conductivity, the pH value and the state of the drilling fluid when the acetic acid aqueous solution is added to 0.23mL, 0.32mL, 0.37mL and 0.45mL, and measuring the demulsification voltage, the conductivity, the pH value and the state of the drilling fluid when the sodium hydroxide is added to 0.013g, 0.025g, 0.03g, 0.04g and 0.07 g; the results are shown in Table 4.
TABLE 4
Figure RE-GDA0002284371160000222
Figure RE-GDA0002284371160000231
As can be seen from the data in table 4, drilling fluids containing the emulsifier composition of the present invention can be converted to an oil-in-water phase after conversion from a water-in-oil phase to a bicontinuous phase with increasing acid addition; when the alkali is added, the oil-in-water phase is changed into the water-in-oil phase along with the increase of the addition amount of the alkali, and the excellent reversible conversion performance is shown.
Test example 5
Conventional drilling fluid SDY 1: the volume ratio is 80: 20 # white oil (from British petrochemical, Guangdong) 5 and 25 wt% CaCl2Brine, 4 wt% of primary emulsifier span 80 (purchased from Ningpo chemical reagent factory), 2 wt% of secondary emulsifier A1, 0.5 wt% of shear strength agent T1 (the content of each additive is based on the total weight of the drilling fluid without the addition of weighting agent), and weighting agent barite for adjusting the density of the drilling fluid to 1.2g/cm3
Soaking a filter cake obtained by a high-temperature high-pressure filtration experiment of the drilling fluid SY5 or SDY1 in a 50 wt% acetic acid aqueous solution for 10min, and observing and recording the removal condition of the acid solution on the filter cake. The filter cake results for drilling fluid SY5 are shown in figure 1. As can be seen from fig. 1, the filter cake of the drilling fluid SY5 is gradually dissolved and dispersed in the acid solution in a short time. Compared with the conventional oil-based drilling fluid SDY1, the mud cake of the drilling fluid SY5 is easier to remove, the steps are less, and the operation is simple.
Test example 6
Conventional drilling fluid SDY 2: the volume ratio is 80: 20 # white oil (from British petrochemical, Guangdong) and 25 wt.% CaCl2The drilling fluid comprises brine, 4 weight percent of main emulsifier C10-C14 calcium alkyl benzene sulfonate, 2 weight percent of auxiliary emulsifier A1, 0.5 weight percent of cutting agent T1 (the content of each additive is based on the total weight of the drilling fluid without the weighting agent), and the weighting agent barite is used for adjusting the density of the drilling fluid to be 1.2g/cm3
Mixing a certain amount of shale cuttings with drilling fluid SY5 or SDY2, and performing hot rolling aging for 2 hours at 80 ℃ to obtain oil-containing shale cuttings. The drill cuttings were soaked in a small amount of 50 wt% acetic acid aqueous solution, 200mL of clear water was added after 10min, and the time taken for the oil shale drill cuttings to completely disperse was recorded, with the results shown in table 5.
A certain amount of sandstone cuttings are taken and dried to constant weight (marked as G1) at 105 ℃, then the sandstone cuttings with certain mass are mixed with drilling fluid SY5 or SDY2, and the mixture is subjected to thermal rolling aging for 2 hours at 80 ℃ to obtain oil-containing sandstone cuttings (marked as G2). The oil-containing sandstone cuttings are cleaned in 50 wt% acetic acid water solution, the cleaned sandstone cuttings are baked to constant weight (marked as G3), and the clearance of the drilling fluid attached to the surface of the oil-containing sandstone is obtained by comparing G1, G2 and G3, and the results are shown in Table 5 and FIG. 2.
TABLE 5
Figure RE-GDA0002284371160000241
As shown in table 5, the conventional oil-based drilling fluid did not have acid-contact reversal performance, and therefore, shale drill cuttings of the conventional oil-based drilling fluid could not be dispersed in water before and after the acid treatment; the drilling fluid SY5 has acid-contact reversal performance, so that shale drill cuttings of the drilling fluid SY5 become hydrophilic after acid treatment and can be dispersed in water.
As shown in fig. 2 and table 5, when not treated by acid, the sandstone cutting surface of the drilling fluid SY5 is covered by a thick layer of drilling fluid SY 5; after acid treatment, almost all the drilling fluid SY5 covered on the surface of the sandstone cutting is removed. Calculated, the clearance rate is more than 90 percent; and the surface of the sandstone drilling cuttings soaked by the conventional drilling fluid is not basically cleaned.
The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.

Claims (19)

1. A method of reversing a soilless phase reversible emulsified drilling fluid, the method comprising: when acid is added, the soil-free phase reversible emulsion drilling fluid is changed from a water-in-oil type to an oil-in-water type or a bicontinuous type; when alkali is added, the oil-in-water type or bicontinuous type emulsified drilling fluid is converted into a water-in-oil type soilless phase reversal emulsified drilling fluid;
the soil-free phase reversible emulsified drilling fluid comprises an additive composition containing a shear-enhancing agent and an emulsifier composition, wherein the emulsifier composition contains a main emulsifier and an auxiliary emulsifier, the main emulsifier is a reversible emulsifier, and the reversible emulsifier contains at least three compounds shown in a formula (1),
formula (1)
Figure FDA0002715071130000011
R is selected from saturated or unsaturated alkyl of C8-C22, R 'and R' are each independently selected from H and alkyl of C1-C3; a 'and A' are each independently selected from O and NH; m + n is more than or equal to 1 and less than or equal to 5;
and, the reversible emulsifier excludes the following: the reversible emulsifier is at least three of compounds shown in the formula (1), wherein R is saturated or unsaturated alkyl of C8-C12, and m + n is more than or equal to 3 and less than or equal to 5;
the coemulsifier is one or more of amide compounds shown in a formula (2);
formula (2) R1-CO-N(R2)-(CH2)x-NH-CO-R3；
Wherein, the group-CO-R3Provided by a saturated or unsaturated fatty acid of C8-C20, the group-CO-R1Provided by a dibasic acid of C2-C10 or anhydride thereof, R2Selected from saturated or unsaturated alkyl of C1-C30, x is an integer of 1-6;
the compound represented by the formula (1) is selected from compounds represented by the following formulae:
formula (1-1): in the formula (1), R is C8 saturated or unsaturated alkyl, m is 1, n is 0;
formula (1-2): in the formula (1), R is C10 saturated or unsaturated alkyl, m is 1, n is 0;
formula (1-3): in the formula (1), R is C12 saturated or unsaturated alkyl, m is 1, n is 0;
formula (1-4): in the formula (1), R is C14 saturated or unsaturated alkyl, m is 1, n is 0;
formula (1-5): in the formula (1), R is C16 saturated or unsaturated alkyl, m is 1, n is 0;
formula (1-6): in the formula (1), R is C18 saturated or unsaturated alkyl, m is 1, n is 0;
case (1): the reversible emulsifier contains a compound represented by formula (1-1), a compound represented by formula (1-2), a compound represented by formula (1-3), a compound represented by formula (1-4), a compound represented by formula (1-5) and a compound represented by formula (1-6); 1-10 wt% of a compound represented by the formula (1-1), 1-10 wt% of a compound represented by the formula (1-2), 30-60 wt% of a compound represented by the formula (1-3), 10-30 wt% of a compound represented by the formula (1-4), 2-15 wt% of a compound represented by the formula (1-5), and 5-20 wt% of a compound represented by the formula (1-6);
alternatively, case (2): the reversible emulsifier contains a compound represented by formula (1-4), a compound represented by formula (1-5) and a compound represented by formula (1-6), wherein the content of the compound represented by formula (1-4) is 1-20 wt%, the content of the compound represented by formula (1-5) is 1-40 wt%, and the content of the compound represented by formula (1-6) is 30-98%.
2. A reversal method according to claim 1, wherein case (1): 2 to 6 weight percent of the compound shown in the formula (1-1), 4 to 10 weight percent of the compound shown in the formula (1-2), 35 to 55 weight percent of the compound shown in the formula (1-3), 15 to 25 weight percent of the compound shown in the formula (1-4), 5 to 15 weight percent of the compound shown in the formula (1-5) and 5 to 15 weight percent of the compound shown in the formula (1-6).
3. A reversal method according to claim 1, wherein case (2): the content of the compound represented by the formula (1-4) is 1-10 wt%, the content of the compound represented by the formula (1-5) is 1-35 wt%, and the content of the compound represented by the formula (1-6) is 50-98%.
4. A reversal method according to claim 3, wherein case (2): the content of the compound represented by the formula (1-4) is 2-8 wt%, the content of the compound represented by the formula (1-5) is 10-35 wt%, and the content of the compound represented by the formula (1-6) is 50-90%.
5. A reversal method according to claim 1, wherein the group-CO-R3Provided by a saturated or unsaturated fatty acid of C10-C18, the group-CO-R1Provided by a dibasic acid of C2-C6 or anhydride thereof, R2Selected from saturated or unsaturated alkyl of C1-C30, and x is an integer of 1-3.
6. A reversal method according to claim 5, wherein the group-CO-R3Provided by saturated fatty acids of C10-C18 or unsaturated fatty acids of C10-C18 containing at least one carbon-carbon double bond, R2Selected from saturated alkyl of C8-C18 or alkyl of C8-C18 containing at least one carbon-carbon double bond.
7. A reversal method according to claim 6, wherein the group-CO-R3Supplied by tall oil fatty acid, oleic acid or linoleic acid; group-CO-R1Is provided by oxalic acid, malonic acid, maleic acid or maleic acid glycoside.
8. A reversal method according to claim 1, wherein the weight ratio of primary and secondary emulsifiers is 100: 2-80.
9. A reversal method according to claim 8, wherein the weight ratio of primary and secondary emulsifiers is 100: 10-50.
10. A reversal method according to claim 9, wherein the weight ratio of primary and secondary emulsifiers is 100: 25-40.
11. A reversal method according to any one of claims 8 to 10, wherein the coemulsifier is prepared by a process comprising:
(1) carrying out first amidation reaction on the compound shown in the formula (2-1) and the compound shown in the formula (2-2) under first amidation reaction conditions to obtain a first amidation reaction product;
(2) under the condition of second amidation reaction, carrying out second amidation reaction on the first amidation reaction product and the compound shown in the formula (2-3) to obtain a second amidation reaction product, namely a second emulsifier;
formula (2-1) R3-COOH；
Formula (2-2) HN (R)2)-(CH2)x-NH2；
Formula (2-3) R1-COOH or an anhydride thereof.
12. The inversion process according to claim 11, the conditions of the first amidation reaction including: the temperature is 140 ℃ and 180 ℃, and the time is 10-24 h;
the conditions of the second amidation reaction include: the temperature is 80-120 ℃ and the time is 2-5 h.
13. A reversal method according to claim 12, wherein the compound represented by formula (2-1) is one or more of tall oil fatty acid, oleic acid and linoleic acid; the compound shown in the formula (2-2) is one or more of N-cocoyl-1, 3-propylene diamine, N-tallow-1, 3-propylene diamine and N-oleyl-1, 3-propylene diamine; the compound shown in the formula (2-3) is one or more of oxalic acid, malonic acid, maleic acid and maleic acid glycoside.
14. A reversal method according to claim 13, wherein the compound represented by formula (2-1), the compound represented by formula (2-2), and the compound represented by formula (2-3) are used in a molar ratio of 1: 0.8-1.5: 0.8-1.5.
15. A reversal method according to claim 14, wherein the compound represented by formula (2-1), the compound represented by formula (2-2), and the compound represented by formula (2-3) are used in a molar ratio of 1: 0.9-1.2: 0.9-1.2.
16. A reversal method according to claim 1, wherein the weight ratio of the emulsifier composition to the shear agent is 100: 2-80.
17. A reversal method according to claim 16, wherein the weight ratio of the emulsifier composition to the shear agent is 100: 10-50.
18. A reversal method according to claim 16, wherein the weight ratio of the emulsifier composition to the shear agent is 100: 20-40.
19. A reversal method according to claim 18, wherein the stripping agent is a dimer acid-organic amine copolymer comprising structural units derived from a dimer acid which is a dimer of oleic acid and linoleic acid, structural units derived from an alkylamine which is one or more of C10-C20 primary alkyl amines, and structural units derived from an aromatic amine which is one or more of aniline and aniline mono-or multi-substituted on the phenyl ring by C1-C3 alkyl groups.
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