High-temperature stabilizer for high-density oil-based drilling fluid as well as preparation method and application of high-temperature stabilizer

Abstract

The invention provides a high-temperature stabilizer for high-density oil-based drilling fluid. The high-temperature stabilizer is prepared from mixed components, the mixed component comprises dodecylbenzene sulfonic acid, an alkaline compound, water, a water-in-oil emulsifier and an oil phase component; the alkaline compound is polybasic alkali and / or an oxide corresponding to the polybasic alkali. Compared with the prior art, the dodecylbenzene sulfonate contained in the high-temperature stabilizer for the high-density oil-based drilling fluid belongs to multi-element metal soap salt, more than two hydrocarbon chains are contained in a molecule, and the high-temperature stabilizer is more oleophylic, is suitable for being used in a W / O type oil-based drilling fluid system, and has the functions of high temperature resistance, wetting and tackifying; other auxiliary emulsion, wetting agent and tackifier do not need to be added in a preparation system, preparation is simple, field operation is convenient, and cost reduction and efficiency improvement are facilitated.

Description

Technical Field

[0001] The invention belongs to the technical field of application of oil-based drilling fluid for deep well and ultra-deep well drilling of petroleum and natural gas, and in particular relates to a high-temperature stabilizer for high-density oil-based drilling fluid, a preparation method and application thereof. Background Art

[0002] With the increasing demand for oil and natural gas in the national economy, unconventional oil and gas and ultra-deep oil and gas have become an important source of energy supply in my country. The exploration and development of deep formation oil and gas reservoirs are constantly increasing at home and abroad, and there are more and more deep and ultra-deep wells. During the drilling process, we face difficulties such as high formation pressure, high downhole temperature, high water sensitivity and easy collapse of mud shale formations, and easy creep of salt-gypsum formations. In the face of such high-temperature, high-pressure and easy-to-collapse formations, it is necessary to use a high-temperature resistant high-density drilling fluid system. In terms of high-temperature resistance and inhibition, the oil-based drilling fluid system has more advantages, but the high-density oil-based drilling fluid system also has problems such as decreased emulsification performance, poor rheological properties and sedimentation instability under high temperature conditions, which is a topic that needs to be solved urgently.

[0003] To prepare a high-density oil-based drilling fluid system that is resistant to high temperatures, not only an emulsifier that is resistant to high temperatures is needed, but also a treatment agent with a wetting function is essential. Dodecylbenzene sulfonate can be used as an auxiliary emulsifier with a wetting function. The Chinese patent with publication number CN111057527A discloses a high-density oil-based drilling fluid and a preparation method thereof. The main emulsifier used is composed of higher fatty acid ester diethylenetriamine, butene polyamide, and polyoxyethylene ether, and the auxiliary emulsifier is sodium dodecylbenzene sulfonate. The main and auxiliary emulsifiers are used to improve the emulsification stability and temperature resistance, and the drilling fluid weighted density reaches 2.0-2.5g / cm 3 , but the preparation temperature is only 150℃, which cannot fully meet the needs of high-temperature deep wells. In addition, sodium dodecylbenzene sulfonate is a monobasic metal soap with only one hydrocarbon chain in the molecule, which is more hydrophilic and easy to form O / W emulsion, but it is not suitable for use in W / O oil-based drilling fluid system. Summary of the invention

[0004] In view of this, the technical problem to be solved by the present invention is to provide a high-temperature stabilizer for high-density oil-based drilling fluid with high-temperature resistance, wetting and viscosity-increasing functions, and a preparation method and application thereof.

[0005] The invention provides a high-temperature stabilizer for high-density oil-based drilling fluid, which is formed by mixed components; the mixed components include: dodecylbenzene sulfonic acid, alkaline compounds, water, water-in-oil emulsifier and oil phase components; the alkaline compounds are polybasic alkalis and / or oxides corresponding to polybasic alkalis.

[0006] Preferably, the mixed components include:

[0007]

[0008] Preferably, the alkaline compound is selected from one or more of calcium oxide, magnesium oxide, aluminum oxide, calcium hydroxide, magnesium hydroxide and aluminum hydroxide;

[0009] The water-in-oil emulsifier is sorbitan fatty acid ester;

[0010] The oil phase component is white oil.

[0011] Preferably, the water-in-oil emulsifier is selected from one or more of Span-20, Span-80 and Span-85;

[0012] The oil phase component is 3# white oil.

[0013] The present invention also provides a method for preparing the above-mentioned high-density oil-based drilling fluid high-temperature stabilizer, comprising the following steps:

[0014] S1) mixing dodecylbenzene sulfonic acid, a basic compound and a portion of the oil phase components to obtain a mixed component;

[0015] S2) adding water to the mixed components under stirring to react, and then adding the remaining oil phase components and the water-in-oil emulsifier to obtain a high-density oil-based drilling fluid high-temperature stabilizer.

[0016] Preferably, the mass ratio of the partial oil phase components to the remaining oil phase components is 1:(1-3);

[0017] The reaction time in step S2) is 0.5 to 1.5 hours.

[0018] The present invention also provides a high-density oil-based drilling fluid, comprising the high-temperature stabilizer for the high-density oil-based drilling fluid.

[0019] Preferably, it also includes an emulsifier represented by formula (I):

[0020]

[0021] Among them, R 1 is a C14-C22 alkyl group; R 2 is a C1-C8 alkylene group;

[0022] A 1 is a substituted or unsubstituted phenylene group, or a substituted or unsubstituted heterocyclylene group;

[0023] A 2 With A 2 ' are each independently selected from H or a group represented by formula (II), and are not H at the same time;

[0024]

[0025] R 3 is a substituted or unsubstituted C1-C12 alkyl group;

[0026] The substituents in the substituted phenylene group and the substituted heterocyclylene group are each independently selected from C1 to C5 alkyl groups;

[0027] The substituent in the substituted C1-C12 alkyl group is selected from amino group or hydroxyl group.

[0028] Preferably, the mass of the high-density oil-based drilling fluid high-temperature stabilizer is 3% to 5% of the mass of the high-density oil-based drilling fluid;

[0029] The mass of the emulsifier represented by formula (I) is 4% to 6% of the mass of the high-density oil-based drilling fluid.

[0030] Preferably, the oil-water ratio of the high-density oil-based drilling fluid is 85:15 to 95:5;

[0031] The density of the high-density oil-based drilling fluid is 2.0-2.5 g / cm 3 ;

[0032] The aging temperature of the high-density oil-based drilling fluid is 180°C to 220°C.

[0033] The present invention provides a high-density oil-based drilling fluid high-temperature stabilizer, which is formed by a mixed component; the mixed component includes: dodecylbenzene sulfonic acid, an alkaline compound, water, an oil-in-water emulsifier and an oil phase component; the alkaline compound is a polybasic alkali and / or an oxide corresponding to the polybasic alkali. Compared with the prior art, the dodecylbenzene sulfonate contained in the high-density oil-based drilling fluid high-temperature stabilizer provided by the present invention belongs to a polybasic metal soap salt, contains more than two hydrocarbon chains in the molecule, is more oleophilic, is not only suitable for use in a W / O type oil-based drilling fluid system, but also enables the stabilizer to have high temperature resistance, wetting, and viscosity-increasing functions. The preparation system does not need to add other auxiliary emulsions, wetting agents and viscosity-increasing agents, is simple to prepare, and is convenient for on-site operation, which is conducive to reducing costs and increasing efficiency.

[0034] Furthermore, the high-temperature stabilizer for high-density oil-based drilling fluid provided by the present invention can form a synergistic effect with the emulsifier shown in formula (I) at high temperature, further enhancing the system's ability to resist high-temperature viscosity increase, overcoming the demulsification caused by high temperature and the instability of the system caused by the rapid decrease in the viscosity of the system, thereby maintaining the viscosity required by the high-density system at high temperature and thereby improving the emulsification and suspension stability of the system.

[0035] The experimental results show that the density of the high-density oil-based drilling fluid prepared by using the high-temperature stabilizer for high-density oil-based drilling fluid provided by the present invention and the emulsifier represented by formula (I) as key treating agents is 2.0-2.5 g / cm 3The high-density oil-based drilling fluid system was rolled at 220℃ for 16 hours without demulsification and sedimentation, and all performances were good; it was able to maintain stable performance at 200℃ for 72 hours, which makes it possible to solve the problems of high-temperature demulsification, poor rheological properties, and barite sedimentation of high-density oil-based drilling fluids in deep and ultra-deep well drilling. DETAILED DESCRIPTION

[0036] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0037] The invention provides a high-temperature stabilizer for high-density oil-based drilling fluid, which is formed by mixed components; the mixed components include: dodecylbenzene sulfonic acid, alkaline compounds, water, water-in-oil emulsifier and oil phase components; the alkaline compounds are polybasic alkalis and / or oxides corresponding to polybasic alkalis.

[0038] According to the present invention, the mixed components preferably include:

[0039]

[0040] According to the present invention, the content of dodecylbenzene sulfonic acid in the mixed components is preferably 80 to 120 parts by weight; in some embodiments provided by the present invention, the content of dodecylbenzene sulfonic acid in the mixed components is specifically 100 parts by weight, 80 parts by weight, 90 parts by weight, 130 parts by weight, 70 parts by weight or 120 parts by weight.

[0041] According to the present invention, the alkaline compound is a polybasic base and / or an oxide corresponding to the polybasic base; the polybasic base is preferably a polybasic weak base, more preferably one or more of calcium hydroxide, magnesium hydroxide and aluminum hydroxide; the oxide corresponding to the polybasic base is preferably an oxide corresponding to a polybasic weak base, more preferably one or more of calcium oxide, magnesium oxide and aluminum oxide; dodecylbenzenesulfonic acid can react with the alkaline compound to generate a dodecylbenzenesulfonic acid polymetallic soap salt having high temperature resistance and wetting effects; the content of the alkaline compound in the mixed component is preferably 6 to 10 parts by weight; in some embodiments provided by the present invention, the content of the alkaline compound in the mixed component is specifically 6 parts by weight, 9 parts by weight, 8 parts by weight, 10 parts by weight or 4 parts by weight.

[0042] According to the present invention, the water is preferably pure water; the content of the water in the mixed components is preferably 6 to 8 parts by weight; in some embodiments provided by the present invention, the content of the water in the mixed components is specifically 8 parts by weight, 6 parts by weight, 7 parts by weight, 9 parts by weight or 5 parts by weight.

[0043] According to the present invention, the water-in-oil emulsifier is preferably sorbitan fatty acid ester, which has the effects of emulsification and viscosity increase. Through emulsification, the compatibility of the components of the product can be promoted to make the product more uniform and stable. In the present invention, it is more preferably one or more of Span-20, Span-80 and Span-85; the content of the water-in-oil emulsifier in the mixed component is preferably 7 to 11 parts by weight; in some embodiments provided by the present invention, the content of the water-in-oil emulsifier in the mixed component is specifically 10 parts by weight, 7 parts by weight, 9 parts by weight, 12 parts by weight, 6 parts by weight or 11 parts by weight.

[0044] The oil phase component plays a role of dispersion and dilution, so that the high temperature stabilizer has good fluidity for easy on-site use. In the present invention, the oil phase component is preferably white oil, more preferably 3# white oil; the content of the oil phase component in the mixed component is preferably 40 to 60 parts by weight; in some embodiments provided by the present invention, the content of the oil phase component in the mixed component is specifically 50 parts by weight, 40 parts by weight, 45 parts by weight, 65 parts by weight, 35 parts by weight or 60 parts by weight.

[0045] The dodecylbenzene sulfonate contained in the high-temperature stabilizer for high-density oil-based drilling fluid provided by the present invention belongs to a polymetallic soap salt, contains more than two hydrocarbon chains in the molecule, is more oleophilic, is not only suitable for use in a W / O type oil-based drilling fluid system, but also enables the stabilizer to have high temperature resistance, wetting and viscosity-increasing functions. The preparation system does not need to add other auxiliary emulsions, wetting agents and viscosity-increasing agents, the preparation is simple, and on-site operation is convenient, which is conducive to cost reduction and efficiency improvement.

[0046] The present invention also provides a method for preparing the above-mentioned high-density oil-based drilling fluid high-temperature stabilizer, comprising the following steps: S1) mixing dodecylbenzene sulfonic acid, an alkaline compound and part of the oil phase components to obtain a mixed component; S2) adding water to the mixed component under stirring conditions for reaction, and then adding the remaining oil phase components and an oil-in-water emulsifier to obtain the high-density oil-based drilling fluid high-temperature stabilizer.

[0047] The present invention has no particular limitation on the source of the raw materials, which can be commercially available. The types and contents of the dodecylbenzenesulfonic acid, alkaline compound, oil phase component, water and water-in-oil emulsifier are the same as those described above and will not be described in detail here.

[0048] Dodecylbenzenesulfonic acid, a basic compound and a part of the oil phase components are mixed to obtain a mixed component.

[0049] Under stirring conditions, water is added to the mixed components for reaction; the stirring speed is preferably 200-350 rpm, more preferably 220-320 rpm, and more preferably 250-300 rpm; since the reaction after adding water is an exothermic reaction, the heat generated can promote the reaction of dodecylbenzenesulfonic acid and the alkaline compound; in the present invention, the water is preferably added slowly to control the reaction speed and make the reaction more gentle; the reaction time is preferably 0.5-1.5 h, more preferably 0.8-1.5 h.

[0050] Then, the remaining oil phase components and the water-in-oil emulsifier are added to obtain a high-temperature stabilizer for high-density oil-based drilling fluid; the mass ratio of the part of the oil phase components to the remaining oil phase components is preferably 1: (1-3), more preferably 1: (1.6-2.5); in some embodiments provided by the present invention, the mass ratio of the part of the oil phase components to the remaining oil phase components is specifically 1: 2, 3: 7, 3: 5, 4: 9 or 1: 2.5; in the present invention, it is preferred to add the remaining oil phase components first, and then add the water-in-oil emulsifier; after adding the water-in-oil emulsifier, it is preferably stirred for 1-2 hours to obtain a high-temperature stabilizer for high-density oil-based drilling fluid.

[0051] The preparation method of the high-density oil-based drilling fluid high-temperature stabilizer provided by the invention is simple and easy to operate, can be completed through a self-heating reaction, does not require heating equipment, is energy-saving, environmentally friendly, and is convenient for production.

[0052] The high-temperature stabilizer prepared by the invention is a milky white to light yellow liquid. The anionic surfactant dodecylbenzenesulfonic acid polymetallic soap salt with high temperature resistance and wetting functions is obtained by neutralization reaction of dodecylbenzenesulfonic acid and polybasic alkali. The sorbitan fatty acid ester belongs to a nonionic surfactant with emulsification and viscosity-increasing functions. In the product preparation process, the compatibility of various components can be promoted through emulsification, so that the product is more uniform and stable. The white oil plays the role of dispersion and dilution, so that the product has good fluidity and is convenient for on-site use.

[0053] The present invention also provides a high-density oil-based drilling fluid, comprising the high-temperature stabilizer for the high-density oil-based drilling fluid.

[0054] According to the present invention, the mass of the high-temperature stabilizer for high-density oil-based drilling fluid is preferably 3% to 5% of the mass of the high-density oil-based drilling fluid.

[0055] According to the present invention, the high-density oil-based drilling fluid preferably further comprises an emulsifier represented by formula (I):

[0056]

[0057] Among them, R 1is a C9-C22 alkyl group, preferably a C14-C22 alkyl group; R 2 It is a C1-C8 alkylene group.

[0058] A 1 is a substituted or unsubstituted phenylene group, a substituted or unsubstituted heterocyclylene group; the substituents in the substituted phenylene group and the substituted heterocyclylene group are each independently a C1-C5 alkyl group, preferably a C1-C3 alkyl group, and more preferably a methyl group; the heterocyclylene group is preferably a hetero-five-membered cyclylene group or a hetero-six-membered cyclylene group; the heteroatoms in the heterocyclylene group are heteroatoms well known to those skilled in the art, and are not particularly limited, and are preferably O, S or N in the present invention; in the present invention, the heterocyclylene group is preferably a pyridylene group; the A 1 The most preferred is tolylene or pyridylene, further specifically:

[0059]

[0060] A 2 With A 2 ' are each independently H or a group represented by formula (II), and are not H at the same time.

[0061]

[0062] R 3 is a substituted or unsubstituted C1-C12 alkyl group; the substituent in the substituted C1-C12 alkyl group is preferably an amino group or a hydroxyl group.

[0063] In the present invention, the emulsifier represented by formula (I) is preferably prepared according to the following steps: a diamino compound and a dibasic acid are mixed and heated to react, a fatty amine is added to continue the heating reaction, and an alkyl sulfonic acid compound is added to react to obtain the emulsifier represented by formula (I); the diamino compound is preferably diaminotoluene and / or diaminopyridine, more preferably 2,6-diaminotoluene and / or 2,6-diaminopyridine; the dibasic acid is preferably one or more of C3-C10 dibasic fatty acids, more preferably one or more of malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid and sebacic acid; the fatty amine is preferably one or more of C9-C22 fatty amines, more preferably one or more of C14-C22 fatty amines, and more preferably one or more of tetradecylamine, hexadecylamine, oleylamine, octadecylamine, eicosylamine and docosylamine; the number of carbon atoms in the alkyl sulfonic acid compound is preferably 1 to 12; In the present invention, the alkyl sulfonic acid compound is preferably one or more of methanesulfonic acid, taurine, 3-hydroxypropanesulfonic acid, 1-butanesulfonic acid, hexane sulfonate, octylsulfonic acid, dodecylsulfonic acid and dodecylbenzenesulfonic acid; the molar ratio of the diamino compound, dibasic acid, fatty amine and alkyl sulfonic acid compound is preferably 1: (1.5-2): (0.5-1): (1-2); the temperature of the mixed heating reaction, the continued heating reaction and the reaction of adding the alkyl sulfonic acid compound is preferably 140°C-180°C; the time of the mixed heating reaction, the continued heating reaction and the reaction of adding the alkyl sulfonic acid compound is preferably 2-4h; the mixed heating reaction, the continued heating reaction and the reaction of adding the alkyl sulfonic acid compound are preferably carried out under stirring; after the reaction of adding the alkyl sulfonic acid compound, preferably after cooling to room temperature, a black-brown solid emulsifier is obtained, which is the emulsifier shown in formula (I).

[0064] The mass of the emulsifier represented by formula (I) is preferably 4% to 6% of the mass of the high-density oil-based drilling fluid.

[0065] The high-temperature stabilizer for high-density oil-based drilling fluid provided by the present invention can form a synergistic effect with the emulsifier shown in formula (I) at high temperature, further enhancing the system's ability to resist high-temperature viscosity increase, overcoming the demulsification caused by high temperature and the instability of the system caused by the rapid decrease in the viscosity of the system, thereby maintaining the viscosity required by the high-density system at high temperature and improving the emulsification and suspension stability of the system.

[0066] According to the present invention, the high-density oil-based drilling fluid preferably also includes a base oil; the base oil is preferably diesel and / or white oil, more preferably 0# diesel or 3# white oil.

[0067] According to the present invention, the high-density oil-based drilling fluid preferably also includes an aqueous phase; the aqueous phase is preferably a calcium chloride aqueous solution; the mass concentration of the calcium chloride aqueous solution is preferably 20% to 30%, more preferably 25%.

[0068] According to the present invention, the oil-water ratio of the high-density oil-based drilling fluid is preferably 85:15 to 95:5.

[0069] According to the present invention, the high-density oil-based drilling fluid preferably also includes a viscosity enhancer; the content of the viscosity enhancer in the high-density oil-based drilling fluid is preferably 4 to 8 g / mL, more preferably 4 to 7.6 g / mL; the viscosity enhancer can be a viscosity enhancer well known to those skilled in the art, without any special restrictions, and is preferably organic soil in the present invention.

[0070] According to the present invention, the high-density oil-based drilling fluid preferably also includes a fluid loss reducer; the content of the fluid loss reducer in the high-density oil-based drilling fluid is preferably 3-13 g / mL, more preferably 5-10 g / mL, further preferably 7-9 g / mL, and most preferably 8 g / mL; the fluid loss reducer can be a fluid loss reducer well known to those skilled in the art, without any special restrictions, and is preferably oxidized asphalt in the present invention.

[0071] According to the present invention, the high-density oil-based drilling fluid preferably also includes an alkalinity regulator; the content of the alkalinity regulator in the high-density oil-based drilling fluid is preferably 3-10 g / mL, more preferably 5-8 g / mL, and even more preferably 6 g / mL; the alkalinity regulator is preferably calcium oxide and / or magnesium oxide.

[0072] According to the present invention, the high-density oil-based drilling fluid preferably also includes a weighting agent; the density of the drilling fluid is adjusted by the weighting agent; the weighting agent can be a weighting agent well known to those skilled in the art, and there is no special limitation. In the present invention, it is preferably one or more of barite, iron ore powder and manganese tetraoxide.

[0073] According to the present invention, the density of the high-density oil-based drilling fluid is preferably 2.0 to 2.5 g / cm 3 .

[0074] According to the present invention, the aging temperature of the high-density oil-based drilling fluid is preferably 180°C to 220°C.

[0075] In order to further illustrate the present invention, the present invention provides a high-density oil-based drilling fluid high-temperature stabilizer, a preparation method and application thereof are described in detail below in conjunction with embodiments.

[0076] The reagents used in the following examples are all commercially available and strictly follow industry standards; among them, dodecylbenzene sulfonic acid was purchased from Linyi Lvsen Chemical Co., Ltd. (96% effective content), an industrial product; sorbitan fatty acid ester was purchased from Hai'an Petrochemical Plant, Jiangsu Province, an industrial product; calcium oxide, magnesium oxide, aluminum oxide, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, and sodium dodecylbenzene sulfonate were all purchased from Sinopharm Reagents, chemically pure; white oil was purchased from Hubei Jingmen Petrochemical's 3# white oil, an industrial product; oxidized asphalt was Puyang Meijing Chemical Materials Co., Ltd. The high temperature resistant emulsifier used in Examples 7 to 12 was prepared according to Example 1 in the Chinese patent with application number 2021114686473.

[0077] The performance of the high-density oil-based drilling fluid high-temperature stabilizer prepared in the following examples will be reflected by the sedimentation stability, rheological properties, electrical stability, etc. of the prepared high-temperature resistant high-density oil-based drilling fluid after high-temperature aging.

[0078] Example 1

[0079] In a reactor equipped with a stirring rod and a thermometer, 100 g of dodecylbenzenesulfonic acid, 15 g of white oil and 6 g of magnesium oxide were added successively and stirred evenly. After the solid and liquid were evenly mixed, 8 g of pure water was slowly dripped in while stirring and reacted for 0.8 h. After the reaction was completed, 35 g of white oil was added and mixed evenly. Finally, 10 g of Span-85 was added and stirred for 1 h to obtain a high-temperature stabilizer W1.

[0080] Example 2

[0081] In a reactor equipped with a stirring rod and a thermometer, 80 g of dodecylbenzenesulfonic acid, 15 g of white oil and 9 g of calcium hydroxide were added successively and stirred evenly. After the solid and liquid were evenly mixed, 6 g of pure water was slowly dripped in while stirring and reacted for 1 hour. After the reaction was completed, 25 g of white oil was added and mixed evenly. Finally, 7 g of Span-80 was added and stirred for 1.5 hours to obtain a high-temperature stabilizer W2.

[0082] Example 3

[0083] In a reactor equipped with a stirring rod and a thermometer, 90 g of dodecylbenzenesulfonic acid and 15 g of white oil were added successively and stirred evenly. Then, 8 g of magnesium hydroxide was slowly added while stirring. After the solid and liquid were evenly mixed, 7 g of pure water was slowly dropped while stirring and reacted for 1.5 h. After the reaction was completed, 30 g of white oil was added and mixed evenly. Finally, 9 g of Span-85 was added and stirred for 2 h to obtain a high-temperature stabilizer W3.

[0084] Example 4

[0085] In a reactor equipped with a stirring rod and a thermometer, 130 g of dodecylbenzenesulfonic acid and 20 g of white oil were added successively and stirred evenly. Then, 10 g of aluminum hydroxide was slowly added while stirring. After the solid and liquid were evenly mixed, 9 g of pure water was slowly added dropwise while stirring and reacted for 1 hour. After the reaction was completed, 45 g of white oil was added and mixed evenly. Finally, 12 g of Span-20 was added and stirred for 1 hour to obtain a high-temperature stabilizer W4.

[0086] Example 5

[0087] In a reactor equipped with a stirring rod and a thermometer, 70 g of dodecylbenzenesulfonic acid and 10 g of white oil were added successively and stirred evenly. Then, 4 g of alumina was slowly added while stirring. After the solid and liquid were evenly mixed, 5 g of pure water was slowly dropped while stirring and reacted for 1.5 h. After the reaction was completed, 25 g of white oil was added and mixed evenly. Finally, 6 g of Span-80 was added and stirred for 2 h to obtain a high-temperature stabilizer W5.

[0088] Example 6

[0089] In a reactor equipped with a stirring rod and a thermometer, 120 g of dodecylbenzenesulfonic acid and 20 g of white oil were added successively and stirred evenly. Then, 10 g of calcium oxide was slowly added while stirring. After the solid and liquid were evenly mixed, 8 g of pure water was slowly added dropwise while stirring and reacted for 1 hour. After the reaction was completed, 40 g of white oil was added and mixed evenly. Finally, 11 g of Span-20 was added and stirred for 2 hours to obtain a high-temperature stabilizer W6.

[0090] Example 7

[0091] A high-density oil-based drilling fluid formula with high temperature resistance (prepared density 2.2g / cm 3 ):

[0092] Base liquid (3# white oil): 170mL;

[0093] 25% CaCl 2 Aqueous solution: 20 mL;

[0094] Based on base fluid and CaCl 2 The total volume fraction of the aqueous solution (190 parts) is the following components in mass volume ratio:

[0095] Organic soil: 7.6 g / mL;

[0096] High temperature resistant solid emulsifier: 11.4g / mL;

[0097] High temperature stabilizer (prepared in Example 1): 5.7 g / mL;

[0098] Oxidized asphalt (fluid loss reducer): 7.6 g / mL;

[0099] Calcium oxide: 5.7 g / mL;

[0100] Barite: 550g / mL.

[0101] Preparation method:

[0102] Add the base liquid 3# white oil in the volume fraction into a high stirring cup, then add the high temperature resistant solid emulsifier in the mass volume ratio while stirring for 10 minutes (stirring speed 11000r / min, the same below), and then add the CaCl in the mass volume ratio under high-speed stirring. 2 The aqueous solution was stirred at high speed for 20 minutes; then the organic soil of the mass volume ratio was added and stirred at high speed for 5 minutes; then the filtrate reducer of the mass volume ratio was added and stirred at high speed for 5 minutes; then the CaO of the mass volume ratio was added and stirred at high speed for 5 minutes; then the high temperature stabilizer of the mass volume ratio was added and stirred at high speed for 10 minutes; then the barite of the mass volume ratio was added to adjust the drilling fluid density to 2.2 g / cm 3 , stir at high speed for 20 minutes, put it into an aging tank and roll age it at 200℃ for 16 hours to obtain a high-density oil-based drilling fluid that is resistant to high temperatures.

[0103] Example 8

[0104] A high-density oil-based drilling fluid formula with high temperature resistance (prepared density 2.5g / cm 3 ):

[0105] Base fluid (0# diesel): 180mL;

[0106] 25% CaCl 2 Aqueous solution: 20 mL;

[0107] Based on base fluid and CaCl 2 The total volume fraction of the aqueous solution (200 parts) is the following components in mass volume ratio:

[0108] Organic soil: 4g / mL;

[0109] High temperature resistant solid emulsifier: 8g / mL;

[0110] High temperature stabilizer (prepared in Example 2): 10 g / mL;

[0111] Oxidized asphalt (filtration loss reducer): 8g / mL;

[0112] Calcium oxide: 6 g / mL;

[0113] Barite: 850g / mL.

[0114] Preparation method:

[0115] Add the base liquid 0# diesel in the volume fraction into a high-stirring cup, then add the high-temperature resistant solid emulsifier in the mass volume ratio while stirring, stir at high speed for 10 minutes (stirring speed 11000r / min, the same below), and then add the CaCl in the mass volume ratio under high-speed stirring. 2 The aqueous solution was stirred at high speed for 20 minutes; then the organic soil of the mass volume ratio was added and stirred at high speed for 5 minutes; then the filtrate reducer of the mass volume ratio was added and stirred at high speed for 5 minutes; then the CaO of the mass volume ratio was added and stirred at high speed for 5 minutes; then the high temperature stabilizer of the mass volume ratio was added and stirred at high speed for 10 minutes; then the barite of the mass volume ratio was added to adjust the drilling fluid density to 2.5g / cm 3 , stir at high speed for 20 minutes, put it into an aging tank and roll age it at 180℃ for 16 hours to obtain a high-density oil-based drilling fluid that is resistant to high temperatures.

[0116] Example 9

[0117] A high-density oil-based drilling fluid formula with high temperature resistance (prepared density 2.4g / cm 3 ):

[0118] Base fluid (0# diesel): 190mL;

[0119] 25% CaCl 2 Aqueous solution: 10mL;

[0120] Based on base fluid and CaCl 2 The total volume fraction of the aqueous solution (200 parts) is the following components in mass volume ratio:

[0121] Organic soil: 4g / mL;

[0122] High temperature resistant solid emulsifier: 12g / mL;

[0123] High temperature stabilizer (prepared in Example 3): 9 g / mL;

[0124] Oxidized asphalt (filtration loss reducer): 8g / mL;

[0125] Calcium oxide: 6 g / mL;

[0126] Barite: 740 g / mL.

[0127] Preparation method:

[0128] Add the base liquid 0# diesel in the volume fraction into a high-stirring cup, then add the high-temperature resistant solid emulsifier in the mass volume ratio while stirring, stir at high speed for 10 minutes (stirring speed 11000r / min, the same below), and then add the CaCl in the mass volume ratio under high-speed stirring.2 The aqueous solution was stirred at high speed for 20 minutes; then the organic soil of the mass volume ratio was added and stirred at high speed for 5 minutes; then the filtrate reducer of the mass volume ratio was added and stirred at high speed for 5 minutes; then the CaO of the mass volume ratio was added and stirred at high speed for 5 minutes; then the high temperature stabilizer of the mass volume ratio was added and stirred at high speed for 10 minutes; then the barite of the mass volume ratio was added to adjust the drilling fluid density to 2.4 g / cm 3 , stir at high speed for 20 minutes, put it into an aging tank and roll age it at 220℃ for 16 hours to obtain a high-density oil-based drilling fluid that is resistant to high temperatures.

[0129] Example 10

[0130] A high-density oil-based drilling fluid formula with high temperature resistance (prepared density 2.5g / cm 3 ):

[0131] Base liquid (3# white oil): 180mL;

[0132] 25% CaCl 2 Aqueous solution: 20 mL;

[0133] Based on base fluid and CaCl 2 The total volume fraction of the aqueous solution (200 parts) is the following components in mass volume ratio:

[0134] Organic soil: 4g / mL;

[0135] High temperature resistant solid emulsifier: 12g / mL;

[0136] High temperature stabilizer (prepared in Example 4): 10 g / mL;

[0137] Oxidized asphalt (filtration loss reducer): 8g / mL;

[0138] Calcium oxide: 6 g / mL;

[0139] Barite: 850g / mL.

[0140] Preparation method:

[0141] Add the base liquid 3# white oil in the volume fraction into a high stirring cup, then add the high temperature resistant solid emulsifier in the mass volume ratio while stirring for 10 minutes (stirring speed 11000r / min, the same below), and then add the CaCl in the mass volume ratio under high-speed stirring. 2The aqueous solution was stirred at high speed for 20 minutes; then the organic soil of the mass volume ratio was added and stirred at high speed for 5 minutes; then the filtrate reducer of the mass volume ratio was added and stirred at high speed for 5 minutes; then the CaO of the mass volume ratio was added and stirred at high speed for 5 minutes; then the high temperature stabilizer of the mass volume ratio was added and stirred at high speed for 10 minutes; then the barite of the mass volume ratio was added to adjust the drilling fluid density to 2.5g / cm 3 , stir at high speed for 20 minutes, put it into an aging tank and roll age it at 210℃ for 16 hours to obtain a high-density oil-based drilling fluid that is resistant to high temperatures.

[0142] Embodiment 11

[0143] A high-density oil-based drilling fluid formula with high temperature resistance (prepared density 2.3g / cm 3 ):

[0144] Base fluid (0# diesel): 170mL;

[0145] 25% CaCl 2 Aqueous solution: 30mL;

[0146] Based on base fluid and CaCl 2 The total volume fraction of the aqueous solution (200 parts) is the following components in mass volume ratio:

[0147] Organic soil: 6 g / mL;

[0148] High temperature resistant solid emulsifier: 10g / mL;

[0149] High temperature stabilizer (prepared in Example 5): 8 g / mL;

[0150] Oxidized asphalt (filtration loss reducer): 8g / mL;

[0151] Calcium oxide: 6 g / mL;

[0152] Barite: 640 g / mL.

[0153] Preparation method:

[0154] Add the base liquid 0# diesel in the volume fraction into a high-stirring cup, then add the high-temperature resistant solid emulsifier in the mass volume ratio while stirring, stir at high speed for 10 minutes (stirring speed 11000r / min, the same below), and then add the CaCl in the mass volume ratio under high-speed stirring. 2The aqueous solution was stirred at high speed for 20 minutes; then the organic soil of the mass volume ratio was added and stirred at high speed for 5 minutes; then the filtrate reducer of the mass volume ratio was added and stirred at high speed for 5 minutes; then the CaO of the mass volume ratio was added and stirred at high speed for 5 minutes; then the high temperature stabilizer of the mass volume ratio was added and stirred at high speed for 10 minutes; then the barite of the mass volume ratio was added to adjust the drilling fluid density to 2.3 g / cm 3 , stir at high speed for 20 minutes, put it into an aging tank and roll age it at 190℃ for 16 hours to obtain a high-density oil-based drilling fluid that is resistant to high temperatures.

[0155] Example 12

[0156] A high-density oil-based drilling fluid formula with high temperature resistance (prepared density 2.4g / cm 3 ):

[0157] Base liquid (3# white oil): 180mL;

[0158] 25% CaCl 2 Aqueous solution: 20 mL;

[0159] Based on base fluid and CaCl 2 The total volume fraction of the aqueous solution (200 parts) is the following components in mass volume ratio:

[0160] Organic soil: 4g / mL;

[0161] High temperature resistant solid emulsifier: 12g / mL;

[0162] High temperature stabilizer (prepared in Example 6): 10 g / mL;

[0163] Oxidized asphalt (filtration loss reducer): 8g / mL;

[0164] Calcium oxide: 8 g / mL;

[0165] Barite: 730 g / mL.

[0166] Preparation method:

[0167] Add the base liquid 3# white oil in the volume fraction into a high stirring cup, then add the high temperature resistant solid emulsifier in the mass volume ratio while stirring for 10 minutes (stirring speed 11000r / min, the same below), and then add the CaCl in the mass volume ratio under high-speed stirring. 2The aqueous solution was stirred at high speed for 20 minutes; then the organic soil of the mass volume ratio was added and stirred at high speed for 5 minutes; then the filtrate reducer of the mass volume ratio was added and stirred at high speed for 5 minutes; then the CaO of the mass volume ratio was added and stirred at high speed for 5 minutes; then the high temperature stabilizer of the mass volume ratio was added and stirred at high speed for 10 minutes; then the barite of the mass volume ratio was added to adjust the drilling fluid density to 2.4 g / cm 3 , stir at high speed for 20 minutes.

[0168] Prepare three identical slurries according to the above preparation method:

[0169] The first portion was placed in an aging tank and aged at 200°C for 16 hours.

[0170] The second portion was placed in an aging tank and aged at 200°C for 72 hours.

[0171] The third portion was placed in an aging tank and aged at 200°C for 16 hours, taken out and cooled to about 60°C, stirred at high speed for 10 minutes, and then placed in an aging tank and allowed to stand at 200°C for 24 hours. After standing, it was taken out, naturally cooled to about 60°C, and the tank was opened. A glass rod was placed in the aging tank to observe the sedimentation stability of the slurry.

[0172] This example is intended to simultaneously test the long-term high temperature resistance and sedimentation stability of the provided high temperature resistant and high density oil-based drilling fluid system.

[0173] Comparative Example 1

[0174] A high-temperature resistant high-density oil-based drilling fluid was prepared according to the method described in Example 12. The difference from Example 12 is that no high-temperature stabilizer was added.

[0175] Comparative Example 2

[0176] A high-density oil-based drilling fluid with high temperature resistance was prepared according to the method described in Example 12. The difference from Example 12 was that 10 g of the high-temperature stabilizer was replaced with 10 g of sodium dodecylbenzene sulfonate (Chinese medicine reagent, chemically pure).

[0177] Example 13

[0178] According to the method of national standard GB / T 16783.2-2012 "Field Test of Drilling Fluids in Petroleum and Natural Gas Industry Part 2: Oil-based Drilling Fluids", the high-density oil-based drilling fluids prepared in Examples 7 to 12 and Comparative Examples 1 to 2 were tested for high temperature resistance, and the test results are shown in Table 1.

[0179] Table 1 Test results of high temperature resistance of high density oil-based drilling fluid

[0180]

[0181] Note: AV is the apparent viscosity, PV is the plastic viscosity, YP is the dynamic shear force, Q 10s For initial cutting, HTHP FL is the high temperature and high pressure filtration loss, ES is the emulsion breaking voltage.

[0182] As shown in Table 1, the high-density oil-based drilling fluid high-temperature stabilizer provided by the present invention has the functions of high-temperature resistance, wetting and viscosity enhancement. When used in combination with the high-temperature resistant emulsifier, a high-density oil-based drilling fluid system with high-temperature resistance can be prepared. The high-density oil-based drilling fluid system has a high-temperature resistance at a temperature of 180°C to 220°C and a density of 2.2 to 2.5 g / cm 3 The emulsification stability, suspension stability and rheology of the system can be well maintained within the range, and various properties can be kept stable by rolling at a constant temperature of 200°C for 72 hours, and can be easily stirred by rolling at 200°C for 16 hours and then standing for 24 hours. By comparing the data of Example 12 and Comparative Example 1, it can be seen that the present invention has a good synergistic effect with the high temperature resistant emulsifier, and can make the high-density oil-based drilling fluid system have better temperature resistance and emulsification and suspension stability, and can meet the needs of high-temperature deep well drilling. By comparing the data of Example 12 and Comparative Example 2, it can be seen that the high-temperature stabilizer containing polymetallic soap salt of dodecylbenzene sulfonate is significantly better than sodium dodecylbenzene sulfonate in the emulsification stability of the high-temperature oil-based drilling fluid system.

[0183] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention, but the present invention is not limited thereto. Those skilled in the art can understand that within the technical concept of the present invention, the technical solution of the present invention can be modified, or some technical features can be combined in any other way. These modifications or combinations do not make the essence of the corresponding technical solution deviate from the spirit and scope of each implementation of the technical solution of the present invention, and should be regarded as the contents disclosed by the present invention, which belong to the protection scope of the present invention.

Claims

1. A high-temperature stabilizer for high-density oil-based drilling fluid, characterized in that: It is formed by mixed components; the mixed components include: dodecylbenzene sulfonic acid, alkaline compounds, water, water-in-oil emulsifier and oil phase components; the alkaline compounds are polybasic bases and / or oxides corresponding to polybasic bases.

2. The high-temperature stabilizer for high-density oil-based drilling fluid according to claim 1, characterized in that: The mixed components include:

3. The high-temperature stabilizer for high-density oil-based drilling fluid according to claim 1, characterized in that: The alkaline compound is selected from one or more of calcium oxide, magnesium oxide, aluminum oxide, calcium hydroxide, magnesium hydroxide and aluminum hydroxide; The water-in-oil emulsifier is sorbitan fatty acid ester; The oil phase component is white oil.

4. The high-temperature stabilizer for high-density oil-based drilling fluid according to claim 3, characterized in that: The water-in-oil emulsifier is selected from one or more of Span-20, Span-80 and Span-85; The oil phase component is 3# white oil.

5. A method for preparing a high-density oil-based drilling fluid high-temperature stabilizer according to claim 1, characterized in that: The following steps are involved: S1) mixing dodecylbenzene sulfonic acid, a basic compound and a portion of the oil phase components to obtain a mixed component; S2) adding water to the mixed components under stirring to react, and then adding the remaining oil phase components and the water-in-oil emulsifier to obtain a high-density oil-based drilling fluid high-temperature stabilizer.

6. The preparation method according to claim 5, characterized in that: The mass ratio of the part of the oil phase components to the remaining oil phase components is 1:(1-3); The reaction time in step S2) is 0.5 to 1.5 hours.

7. A high-density oil-based drilling fluid, characterized in that: The invention comprises the high-temperature stabilizer for high-density oil-based drilling fluid according to any one of claims 1 to 4 or the high-temperature stabilizer for high-density oil-based drilling fluid prepared by the preparation method according to claim 5 or 6.

8. The high-density oil-based drilling fluid according to claim 7, characterized in that: Also included is an emulsifier of formula (I): Wherein, R1 is a C14-C22 alkyl group; R2 is a C1-C8 alkylene group; A1 is a substituted or unsubstituted phenylene group, or a substituted or unsubstituted heterocyclylene group; A2 and A2' are each independently selected from H or a group represented by formula (II), and are not H at the same time; R3 is a substituted or unsubstituted C1-C12 alkyl group; The substituents in the substituted phenylene group and the substituted heterocyclylene group are each independently selected from C1 to C5 alkyl groups; The substituent in the substituted C1-C12 alkyl group is selected from amino group or hydroxy group.

9. The high-density oil-based drilling fluid according to claim 8, characterized in that: The mass of the high-temperature stabilizer for high-density oil-based drilling fluid is 3% to 5% of the mass of the high-density oil-based drilling fluid; The mass of the emulsifier represented by formula (I) is 4% to 6% of the mass of the high-density oil-based drilling fluid.

10. The high-density oil-based drilling fluid according to claim 7, characterized in that: The oil-water ratio of the high-density oil-based drilling fluid is 85:15 to 95:5; The density of the high-density oil-based drilling fluid is 2.0-2.5 g / cm 3 ; The aging temperature of the high-density oil-based drilling fluid is 180°C to 220°C.

Images