High performance emulsifier composition and drilling fluid and use thereof

Abstract

The application discloses a high-performance emulsifier composition, which takes a double fatty-based imidazoline amide, an N-hydroxyethylated fatty-based imidazoline and a maleated fatty acid as effective components and takes oil and / or alcohol ether as a solvent. The application also discloses a drilling fluid using the high-performance emulsifier composition. The emulsifier composition and the oil-based / synthetic-based drilling fluid provided by the application have a temperature resistance of up to 220 DEG C, a density of up to 2.4-2.8 g / cm 3 , a salt water pollution resistance of more than 50%, and excellent rheological property and tight plugging performance.

Description

Technical Field

[0001] This invention relates to high-performance emulsifiers and drilling fluids and their applications. Background Technology

[0002] In the process of oil and gas resource exploration and development, drilling technology forms the necessary channels for oil and gas extraction, which is the first stage in realizing the utilization of oil and gas resources. Therefore, drilling technology is of decisive significance for the efficient development of oil and gas resources. In oil drilling engineering, drilling fluid plays an important role in carrying rock cuttings, lubricating drill tools, and cooling drill bits, and is known as the "blood of drilling engineering".

[0003] Oil-based / synthetic-based drilling fluids are an important type of drilling fluid. Compared with water-based drilling fluids, they have better inhibition, lubrication, high-temperature stability, anti-fouling properties, and reservoir protection. They are increasingly widely used in drilling deep mudstone, shale, and high-temperature gypsum layers. This is a technological field with great development potential in my country's current deep oil and gas resources and shale oil and gas resources sectors.

[0004] The stability of water-in-oil emulsions is fundamental to oil-based drilling fluids and is a key component of their production. In deep wells, ultra-deep wells, and long horizontal shale gas wells, the stability of water-in-oil emulsions directly impacts the success of the drilling operation.

[0005] Commonly used emulsifiers include Span 80, fatty acids, maleic aliphatic polyamides, naphthenic acid amides, calcium dodecylbenzenesulfonate, and sodium rosinate. Musarat Halima Muhammad used aminoamides as emulsifiers and layered double hydroxides as rheology modifiers to prepare oil-based drilling fluids. Li Wuchen et al. prepared oil-based emulsifiers based on dimer acids and long-chain alkyl monoamines and provided an oil-based drilling fluid. Wang Xianguang et al. invented an emulsifier for high-temperature resistant oil-based drilling fluids composed of rosin acid, white oil, alkali, and alkyl sulfonates, with a temperature resistance of 200℃. Li Zhiping et al. invented an emulsifier base material obtained by reacting cashew phenol and epichlorohydrin to obtain glycidyl ether, then reacting it with dimethylamine to generate a tertiary amine, which is then reacted with 1,3-propanesulfonic acid lactone to obtain an emulsifier base material with strong resistance to Ca2+. 2+ Mg 2+The ability to form divalent ions prevents mineralization under high-temperature conditions. Wang Jianhua et al. reacted tall oil acid, maleic anhydride, a first catalyst, and a solvent under heat to obtain a tall oil acid-maleic anhydride adduct; a second catalyst was added to the tall oil acid-maleic anhydride adduct, and after heating to the required reaction temperature, hydroxyethyl ethylenediamine was added, and the reaction was continued for a period of time to obtain the high-efficiency oil-based drilling fluid emulsifier. Liu Yuntao first prepared a tall oil-like fatty acid amide and then carried out a catalytic esterification reaction to prepare an emulsifier for oil-based drilling fluids. Qiao Dibasu Ramasami et al. prepared an alkyl ester emulsifier using waste vegetable oil for the formulation of oil-based drilling fluids. Oil-based / synthetic-based drilling fluids formulated with the above emulsifiers have high plastic viscosity, low high-temperature stability, and poor resistance to brine contamination, which cannot better meet the needs of safe and efficient drilling in deep and ultra-deep wells under complex geological conditions.

[0006] With the development of deep and ultra-deep wells and unconventional oil and gas wells such as shale oil and shale gas, the demand for oil-based / synthetic drilling fluids is increasing. These wells have high downhole temperatures and pressures, and present complex problems such as high-pressure brine layers. This necessitates drilling fluids that not only possess good stability at high temperatures but also exhibit excellent rheological properties and anti-fouling capabilities. Therefore, a high-performance emulsifier and a corresponding oil-based / synthetic drilling fluid are urgently needed. Summary of the Invention

[0007] The present invention aims to provide a high-performance emulsifier suitable for oil-based / synthetic-based drilling fluids, which has a stable chemical structure and can effectively improve the emulsification stability, temperature stability and anti-pollution performance of ultra-deep well oil-based / synthetic-based drilling fluids, and can significantly improve the rheological properties of drilling fluids, so as to at least partially solve the technical defects of existing drilling fluids under high temperature and high pressure, thick salt and gypsum layers and high salinity composite brine layers.

[0008] As one aspect of the present invention, a high-performance emulsifier composition is disclosed, comprising bis-aliphatic imidazoline amide, N-hydroxyethylated aliphatic imidazoline, and maleated fatty acid as active ingredients, and oil (environmentally friendly solvent oil) and / or alcohol ether as solvent.

[0009] In at least one embodiment, the bis-aliphatic imidazoline amide is formed by amidation and cyclization under high temperature conditions of natural plant fatty acids (such as oleic acid, linoleic acid, linolenic acid, palmitic acid, and rosin acid) rich in unsaturated bonds with polyethylene polyamines. Preferably, tall oil fatty acids (Shanghai Lisen Chemical Co., Ltd., hereinafter the same) rich in oleic acid, linoleic acid, and rosin acid are reacted with diethylenetriamine (Nanjing Gutian Chemical) under high temperature conditions via amidation, wherein the molar ratio of fatty acids to diethylenetriamine is greater than 2:1.

[0010] In at least one embodiment, the N-hydroxyethylated fatty acid imidazoline is formed by amidation and catalytic cyclization of natural plant fatty acids rich in unsaturated bonds (such as oleic acid, linoleic acid, linolenic acid, palmitic acid, and rosin acid) with hydroxyethyl ethylenediamine; or by amidation and catalytic cyclization of plant fatty acids with ethylenediamine, followed by further reaction with ethylene oxide to generate hydroxyethyl or hydroxyethyl-terminated polyoxyethylene groups on the nitrogen atom of the fatty acid imidazoline, thus forming the N-hydroxyethylated fatty acid imidazoline. Preferably, the N-hydroxyethylated fatty acid imidazoline is formed by amidation and cyclization at high temperature of tall oil fatty acids rich in oleic acid, linoleic acid, and rosin acid with hydroxyethyl ethylenediamine (Sinopharm Group).

[0011] In at least one embodiment, the maleicized fatty acid is a maleic anhydride-modified natural unsaturated fatty acid produced by reacting maleic anhydride (maleic anhydride) with plant fatty acids rich in unsaturated bonds (such as oleic acid, linoleic acid, linolenic acid, palmitic acid, and rosin acid) under high-temperature conditions through diene synthesis and olefin reaction. Preferably, it is a maleicized tall oil fatty acid prepared by reacting maleic anhydride (from Sinopharm Group) with tall oil fatty acids rich in oleic acid, linoleic acid, and rosin acid under high-temperature conditions.

[0012] The environmentally friendly solvent oil is a dearomatic solvent oil with alkanes and cycloalkanes as the main components, preferably environmentally friendly solvent oil D120 (Luoyang Xinling Petrochemical Co., Ltd.);

[0013] The alcohol ether solvent is a polyol ether polar organic solvent, preferably dipropylene glycol monomethyl ether (Shandong Kejian Chemical Co., Ltd.).

[0014] The high-performance emulsifier composition comprises 60-80 parts by weight of dialiphatic imidazoline amide, 10-15 parts by weight of N-hydroxyethylated aliphatic imidazoline, and 5-30 parts by weight of maleic fatty acid. Preferably, it comprises 75-80 parts by weight of dialiphatic imidazoline amide, 10-15 parts by weight of N-hydroxyethylated aliphatic imidazoline, and 10-15 parts by weight of maleic fatty acid.

[0015] In the high-performance emulsifier composition, the volume ratio of environmentally friendly solvent oil to alcohol ether polar solvent is 40 / 60 to 60 / 40, more preferably 55 / 45.

[0016] In the high-performance emulsifier composition, the volume ratio of the effective component to the solvent is 70 / 30 to 90 / 10, more preferably 85 / 15.

[0017] In another aspect, the invention relates to a drilling fluid, which is an oil-based or synthetic-based drilling fluid, comprising the aforementioned high-performance emulsifier composition. Further, it also includes a base oil, an aqueous phase (typically a calcium chloride solution dispersed in the oil phase to form a water-in-oil emulsion), an organophilic modified clay mineral, a flow pattern modifier, a polymer thickener, an alkalinity modifier, an activity control agent, an organophilic modified humic acid filtration reducer, and weighting materials, etc.

[0018] In oil-based / synthetic-based drilling fluids, the ratio of the added amount of the high-performance emulsifier composition to the total volume of base oil and aqueous phase in the drilling fluid is 50–80 g / L. The volume ratio of base oil to aqueous phase can be 85 / 15–95 / 5. Based on 1L of total volume of base oil and aqueous phase, the following components are added: 25–50 g of organophilic modified clay minerals, 10–20 g of flow pattern regulator, 5–15 g of polymer thickener, 30–50 g of alkalinity regulator, and 30–70 g of organophilic modified lignite filtration reducer. Based on the above composition, the fluid is weighted to the required density using a certain proportion of compounded barite, micro-manganese, and other weighting materials.

[0019] The base oils are diesel oil, mineral oil, and synthetic ultra-low aromatic content environmentally friendly base oils. In some embodiments of the present invention, the base oils used are 0# diesel oil, light white oil, and synthetic environmentally friendly solvent oil ESCAID 110 (produced by ExxonMobil Chemical Company).

[0020] In some embodiments of the present invention, the organophilic modified clay mineral is organophilic modified henchotite (BT38); the flow pattern regulator is polyamide fatty acid (MOD); the alkalinity regulator is calcium hydroxide or calcium oxide; the polymer thickener is a polyolefin block polymer (PRM); the organophilic modified lignite filtration reducer (OLG) and the weighting material is barite (to increase the drilling fluid density to 2.4 g / cm³). 3 Micromanganese (drilling fluid density from 2.4 g / cm³) 3 Increased to 2.6–2.8 g / cm³ 3 ).

[0021] As another aspect of the present invention, it relates to the application of the above-mentioned drilling fluid in the development of deep oil and gas resources and unconventional oil and gas wells.

[0022] The high-performance emulsifier composition provided by this invention transforms the main components of the emulsifier composition from conventional fatty acid polyamides to aliphatic imidazoline amides and N-hydroxyethylated aliphatic imidazoline. In terms of molecular structure, the composition of hydrophilic groups, which are mainly chain-like, is changed to a composition mainly composed of five-membered heterocycles. The adsorption groups of the emulsifier molecules at the oil / water interface are changed from mainly chain-like distribution to ring-shaped adsorption of five-membered heterocycle groups. This makes it easier to achieve complete coverage on the droplets of the reverse emulsion, and the repulsive force of the constructed interfacial film is increased. This can reduce the tendency of emulsion droplets to aggregate and flocculate in high-temperature environments and improve emulsion stability. At the same time, in reverse emulsion drilling fluids, the adsorption capacity of the emulsifier composition on the solid surface of the weighting material particles is improved, and the surface oleophilic wetting properties are also relatively improved. This is beneficial to reduce the surface friction of the weighting material and the tendency of aggregation at high temperatures, and improves the rheology of oil-based / synthetic-based drilling fluids under high solid content conditions and the stability of oily wetting and turning of solid particles.

[0023] The emulsifier composition and oil-based / synthetic-based drilling fluid provided by this invention have a temperature resistance of up to 200℃ and a density as high as 2.4-2.8 g / cm³. 3 It exhibits over 50% resistance to brine contamination and excellent drilling fluid rheological and sealing properties. Under the same conditions, compared to conventional aliphatic polyamide emulsifiers, it requires a concentration reduction of over 30%, maintains emulsification stability at the same level, keeps suspension capacity consistent, reduces plastic viscosity by 40%, and significantly improves rheological properties, thereby significantly increasing hydraulic efficiency, reducing circulating pressure loss, and increasing mechanical drilling speed. Detailed Implementation

[0024] To make the objectives, technical solutions, and effects of the invention clearer, the present invention will be further described in detail with reference to specific embodiments. However, it should be understood that the present invention can be implemented in many forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a clearer and more thorough understanding of the present invention and to clearly introduce the technical concept of the present invention to those skilled in the art.

[0025] The present invention will now be described in detail using specific embodiments. Before describing the specific embodiments in detail, the specific materials used in the present invention will be explained:

[0026] High-performance emulsifier composition: The oil-based drilling fluid emulsifier aliphatic imidazoline amide (denoted as IMA) involved in this invention is referred to as IMA(a), IMA(b), and IMA(c) respectively for comparison to illustrate the different components of the high-performance emulsifier.

[0027] Organically modified clay minerals: Hanktorite (BT38, Elementis) was modified with organically modified high-temperature oil-based drilling fluid viscosifier. The main component is Hanktorite modified with long-chain quaternary ammonium salt cationic surfactant.

[0028] Alkalinity regulator: Commercially available calcium hydroxide or calcium oxide is used.

[0029] Polymer thickener: The oil-based drilling fluid polymer thickener is a polyolefin block copolymer (PRM), whose main components are (substituted) styrene homopolymer segments, olefin copolymer segments, and (substituted) styrene triblock polymers. The commercially available product selected is Kraton G 1701.

[0030] Organically modified lignite filtration reducer: The filtration reducer is an aliphatic amide lignite product prepared by reacting long-chain aliphatic amines with humic acid in lignite. It is an oil-based drilling fluid filtration reducer, aliphatic amide lignite (denoted as OLG, Salk Petroleum Technical Services Company Organic Lignite BLACKLIGO 400).

[0031] Flow pattern modifier: The flow pattern modifier for oil-based drilling fluids is a polymeric amide fatty acid (denoted as MOD), whose main component is a polyamide fatty acid formed by the condensation of polyamines and mixed polyamide fatty acids (dicarboxylic and tricarboxylic fatty acids), and is prepared according to Chinese Patent 201310684666.9.

[0032] Weighting materials: mainly commercially available API barite and Micromax (Shanghai Aiken) ultrafine manganese powder.

[0033] The aforementioned diacid-based imidazoline, N-hydroxyethyl acid-based imidazoline, and maleated fatty acid are prepared according to the following methods:

[0034] Example 1: Dialiphatic imidazoline

[0035] A four-necked flask was installed on an automatic lifting oil bath, equipped with a thermometer, stirrer, vacuum distillation head (connected to a water separator), and PTFE nitrogen line. The tall oil fatty acid was added at a ratio of 2.1:1 (molar number of aliphatic carboxylic acids to diethylenetriamine), with a slight excess of fatty acid. The molar number of aliphatic carboxylic acids in the tall oil fatty acid was determined by measuring its acid value. Tall oil fatty acid (Shanghai Lisen Chemical Co., Ltd.) was added to the four-necked flask, and under nitrogen protection, heated to 75±5℃. A measured amount of diethylenetriamine (Nanjing Gutian Chemical) was then added, and the temperature was increased while stirring. Nitrogen gas was stopped, and the reaction was carried out at 170℃±5℃ for 3.5–4.0 h to induce amidation. The amount of water flowing out of the water separator was monitored and recorded. After the amount of water flowing out stabilized, the temperature was increased to 240℃±5℃ for intramolecular dehydration. The vacuum was controlled at 0.06–0.09 MPa, and the amount of water flowing out of the water separator was monitored and recorded. The reaction was carried out for 4.5–5.0 h. When no more water was added in the water separator, nitrogen gas was introduced to purge the water vapor above the surface of the reaction product liquid. The mixture was then cooled to 80–90℃, discharged, and cooled to room temperature. The resulting product was dialiphatic imidazoline.

[0036] Example 2 N-hydroxyethyl fatty imidazoline

[0037] The synthesis process is similar to that of dialiphatic imidazoline preparation. A four-necked flask is installed on an automatic lifting oil bath, equipped with a thermometer, stirrer, vacuum distillation head (connected to a water separator), and PTFE nitrogen line. The tall oil fatty acid is fed with a ratio of (1.0–1.1):1.0 of the molar number of aliphatic carboxylic acids to hydroxyethyl ethylenediamine, where the molar number of aliphatic carboxylic acids in the tall oil fatty acid is calculated by measuring its acid value. Tall oil fatty acid (Shanghai Lisen Chemical Co., Ltd.) is added to the four-necked flask, and under nitrogen protection, it is heated to 75±5℃. A measured amount of hydroxyethyl ethylenediamine (Nanjing Gutian Chemical) is then added, and the temperature is raised to 100–110℃ under stirring. The temperature is maintained for 1.5 hours to allow the aliphatic carboxylic acid and the amino groups in the hydroxyethyl ethylenediamine to fully form salts, improving the intermolecular amidation effect. Nitrogen gas was stopped, and the reaction was carried out at 170℃±5℃ for 3.5–4.0 h to induce amidation. The amount of water flowing out of the water separator was monitored and recorded. After the amount of water flowing out stabilized, the temperature was increased to 240℃±5℃ for intramolecular dehydration. The vacuum was controlled at 0.06–0.09 MPa, and the amount of water flowing out of the water separator was monitored and recorded. The reaction was carried out for 4.5–5.0 h. When no more water was added in the water separator, nitrogen gas was introduced to purge the water vapor above the surface of the reaction product liquid. The mixture was then cooled to 80–90℃, discharged, and cooled to room temperature. The resulting product was N-hydroxyethyl aliphatic imidazoline.

[0038] Example 3 Maleic fatty acids

[0039] A three-necked flask equipped with a thermometer and reflux condenser is installed on an automatic lifting oil bath. Tall oil fatty acids are added to the flask and heated to 70°C. Maleic anhydride, at 25% of the mass of tall oil fatty acids, is then added. After the addition, the mixture in the flask is heated to 220°C in stages, maintaining each designed temperature for approximately 5–6 minutes. The first heating temperature range is 70°C to 130°C; the second is 130°C to 160°C; the third is 160°C to 185°C; the fourth is 185°C to 205°C; and the fifth is 205°C to 220°C. The reaction temperature is maintained at 220°C for 5 hours, then cooled to 80–90°C. The product is discharged and cooled to room temperature; the obtained product is maleic fatty acid.

[0040] Example 4: The effective component ratio in IMA(a) is bis(aliphatic) imidazoline: N-hydroxyethylated aliphatic imidazoline: maleated fatty acid = 75:10:15;

[0041] Example 5: The effective component ratio in IMA(b) is 75:15:10 for di-aliphatic imidazoline: N-hydroxyethylated aliphatic imidazoline: maleated fatty acid;

[0042] Example 6: The effective component ratio in IMA(c) is 80:15:5 for di-aliphatic imidazoline: N-hydroxyethylated aliphatic imidazoline: maleated fatty acid.

[0043] Example 7: The effective component ratio in IMA(d) is 60:10:30 for di-aliphatic imidazoline: N-hydroxyethylated aliphatic imidazoline: maleated fatty acid.

[0044] Example 8: The effective component ratio in IMA(e) is 60:10:30 for di-aliphatic imidazoline: N-hydroxyethylated aliphatic imidazoline: maleated fatty acid.

[0045] Example 9: The effective component ratio in IMA(f) is 60:10:30 for di-aliphatic imidazoline: N-hydroxyethylated aliphatic imidazoline: maleated fatty acid.

[0046] According to the proportions in Examples 4 to 7, the products obtained in Examples 1 to 3 were accurately weighed, and 17.6 parts of mixed solvent were added to the mixture based on 100 parts by mass. The effective concentration was about 85%. The ratio of environmentally friendly solvent oil D120 to dipropylene glycol methyl ether in the mixed solvent was 60 / 40 (Example 4), 55 / 45 (Example 5), 40 / 60 (Example 6), and 55 / 45 (Example 7), respectively.

[0047] According to the proportions in Example 8, accurately weigh the products obtained in Examples 1 to 3, add 43 parts of mixed solvent (the mixing ratio of active ingredient to solvent is 73 / 30) to the mixture based on 100 parts by mass, the concentration of active ingredient is about 70%, wherein the ratio of environmentally friendly solvent oil D120 to dipropylene glycol methyl ether in the mixed solvent is 55 / 45 respectively.

[0048] According to the proportions in Example 9, accurately weigh the products obtained in Examples 1 to 3, add 11 parts of mixed solvent (the mixing ratio of active ingredient to solvent is 90 / 10) to the mixture based on 100 parts by mass, the concentration of active ingredient is about 90%, wherein the ratio of environmentally friendly solvent oil D120 to dipropylene glycol methyl ether in the mixed solvent is 55 / 45 respectively.

[0049] The preparation procedure for the high-temperature, high-density oil-based / synthetic-based drilling fluid provided by this invention is as follows:

[0050] (1) Measure the base oil, add emulsifier and flow pattern modifier respectively, and stir at 11000±300RPM (rpm) for 5 to 10 minutes;

[0051] (2) Measure out calcium chloride solution and slowly add it to the above base oil, and stir at 11000±300 RPM for 25 to 30 minutes;

[0052] (3) Add alkalinity regulator and organophilic modified clay minerals, and stir at 11000±300 RPM for 10-15 min;

[0053] (4) Add polymer thickener and stir at 11000±300 RPM for 10-15 min;

[0054] (5) Add the filtration loss reducer and the plugging agent, and stir at 11000±300 RPM for 10 to 15 minutes;

[0055] (6) Add weighting material and stir at 11000±300RPM for 30-45 minutes.

[0056] 1. Evaluation and testing of the impact of high-performance emulsifier compositions on the performance of oil-based drilling fluids.

[0057] The high-performance emulsifier compositions IMA(a), IMA(b), and IMA(c) from Examples 4-9 were respectively added to a solution with an oil-to-water ratio of 90 / 10 and a density of 2.2 g / cm³. 3In a water-in-white oil drilling fluid, the dosage is 50 g / L based on the total oil-water volume. The drilling fluid formula is: 204 mL light white oil + emulsifier + 50 g / L flow pattern modifier + 24 mL CaCl2 (20% salt solution) + 50 g / L calcium hydroxide + 50 g / L organophilic modified henchote + 50 g / L filtration loss reducer + 645 g barite, with an oil-water ratio of 90 / 10 and a density of 2.2 g / cm³. 3 The prepared drilling fluid was hot-rolled at 150℃ for 24 hours, and its performance before and after aging was tested according to the recommended method in GB / T 16783.2. The results are shown in Table 1 below.

[0058] Table 1 Performance of high-performance emulsifier compositions

[0059]

[0060]

[0061] The results in the table show that, compared with the comparative example (conventional fatty acid polyamide emulsifier), the high-performance emulsifier composition disclosed in this invention significantly increases the demulsification voltage after hot rolling aging. The rheological properties of the drilling fluid are greatly improved, and the rheological properties before and after aging are relatively stable, reducing plastic viscosity and thus being more conducive to increasing mechanical drilling speed and reducing circulating pressure loss. Regarding dosage, the fatty acid polyamide emulsifier is added at 80 g / L, while the high-performance emulsifier composition is added at 50 g / L, demonstrating the characteristics of low dosage and high efficiency. In the high-performance emulsifier composition, the content of maleic fatty acids is too high (Examples 7-9), resulting in significantly excessive rheological properties of the drilling fluid before aging. Furthermore, with increasing concentration (Example 9, active ingredient content 90%), the rheological properties after aging increase significantly, and the static shear stress is also high, showing a strong increasing trend (Example 9, static shear stress at 10s is 19.6 Pa, while at 10min it reaches 28.8 Pa). Conversely, a low concentration (Example 8, active ingredient 70%) results in a low demulsification voltage of the drilling fluid, decreasing to 683V after aging, indicating a significantly insufficient amount of emulsifier composition required. Moreover, the low effective content of the emulsifier composition not only increases the amount needed for application but also adds unnecessary solvent costs and production and transportation costs.

[0062] 2. Evaluation and testing of the effect of high-performance emulsifier compositions on the temperature resistance of oil-based drilling fluids.

[0063] The drilling fluid prepared using the emulsifier IMA(c) in Example 6 was hot-rolled at 150℃, 180℃, 200℃, and 220℃ for 24 hours. 5–15 g / L of polymer thickener was added to the drilling fluid aged at 180℃–220℃. The performance of the drilling fluid before and after aging was tested according to the recommended method in GB / T16783.2. The results are shown in Table 2.

[0064] Table 2. High-temperature stability evaluation results of high-performance emulsifier compositions

[0065]

[0066] The results above indicate that the oil-based drilling fluid formulated with the high-performance emulsifier composition maintains sufficient high-temperature emulsification stability at temperatures ranging from 150℃ to 220℃. However, due to the high temperature, the rheological properties of the oil-based drilling fluid decrease, and the filtration loss increases, primarily due to the attenuation of the suspending effect of the materials in the drilling fluid at high temperatures. By adding a polymer thickener to the high-temperature aged drilling fluid, the rheological properties of the drilling fluid are effectively maintained or increased, and the emulsification stability is slightly improved, while the high-temperature, high-pressure filtration loss is relatively reduced. This is mainly due to the special triblock structure of the polymer thickener, which, after dissolving in the base oil, increases the viscosity of the base oil and strengthens the network structure in the drilling fluid.

[0067] 3. Evaluation and testing of the resistance of oil-based drilling fluids to brine contamination

[0068] Example 10: The dosage of the high-performance emulsifier composition IMA(c) was increased to 80 g / L, and a formulation with a density of 2.4 g / cm³ was prepared. 3 The diesel-in-water drilling fluid has the following formula (oil-to-water ratio 85 / 15): 204mL #0 diesel + 80g / L emulsifier IMA(c) + 36mL CaCl2 (20% brine) + 20g / L organophilic modified hanktorite + 30g / L CaO + 5g / L flow pattern modifier + 40g / L organophilic modified humic acid filtration reducer + barite powder (weighted to 2.4g / cm³). 3 The drilling fluid, after being hot-rolled at 160℃ for 16 hours, was contaminated with 10% to 80% of the drilling fluid volume of compound brine (200g / L sodium chloride + 100g / L calcium chloride), and its performance parameters after hot rolling were tested. The test results are shown in Table 3.

[0069] Table 3 Evaluation results of the anti-fouling performance of drilling fluids formulated with high-performance emulsifier compositions

[0070]

[0071] The intrusion of highly saline brine has a significant impact on the performance of oil-based drilling fluids. At lower levels of intrusion, the performance changes are minimal. When the brine concentration reaches 30.0%, the drilling fluid exhibits slight thickening. At 50.0%, the viscosity increases significantly. At 80.0%, severe thickening occurs, with the demulsification voltage dropping to 176V. No water separation occurs, and the fluid remains in an oil-in-water state. The diesel-in-water drilling fluid developed in this paper maintains a stable state even under high contamination levels, indicating high resistance to brine contamination. In terms of fluidity, it maintains good flowability even at contamination levels of 30.0%-50.0%.

[0072] 4. Ultra-high density oil-based / synthetic-based drilling fluids and their properties

[0073] Example 11: (Oil-to-water ratio 90:10): 216mL #0 diesel oil + 80g / L emulsifier IMA(c) + 24mL CaCl2 (20% brine) + 25g / L organophilic modified hanktorite + 35g / L CaO + 15g / L flow pattern modifier + 30g / L organophilic modified humic acid filtration reducer + barite powder (weighted to density 2.4g / cm³) 3 ) + micro-manganese mineral powder (weighted to a density of 2.6 g / cm³) 3 )

[0074] Example 12: (Oil-to-water ratio 95:5): 228 mL ESCAID 110 + 80 g / L emulsifier IMA(c) + 12 mL CaCl2 (20% brine) + 18 g / L organophilic modified hanktorite + 35 g / L CaO + 15 g / L flow pattern modifier + 70 g / L organophilic modified humic acid filtration loss reducer + barite powder (weighted to density 2.4 g / cm³) 3 ) + micro-manganese mineral powder (weighted to a density of 2.8 g / cm³) 3 )

[0075] Drilling fluids were prepared according to Examples 11 and 12. After rolling and aging at 160°C for 16 hours, the performance of the drilling fluids after hot rolling was tested. The test results are shown in Table 4.

[0076] Table 4. Performance evaluation results of ultra-high density drilling fluid formulated with high-performance emulsifier combinations.

[0077]

[0078] For the purposes of this invention, it should be further noted that the above embodiments are only used to illustrate the technical solutions of this invention and are not restrictive. Although this invention has been described in detail with reference to the embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of this invention do not depart from the technical concept and scope of this invention, and all such modifications and substitutions should be covered within the scope of the claims of this invention.

Claims

1. A high-performance emulsifier composition, characterized in that, The active components are dialiphatic imidazoline amide, N-hydroxyethylated aliphatic imidazoline, and maleated fatty acids, and the solvents are oil and / or alcohol ethers. The alcohol ether is a polar organic solvent of the polyol ether class; The high-performance emulsifier composition contains 60-80 parts by weight of bis-aliphatic imidazoline amide, 10-15 parts by weight of N-hydroxyethylated aliphatic imidazoline, and 5-30 parts by weight of maleic fatty acid. In the high-performance emulsifier composition, the volume ratio of the effective component to the solvent is 70 / 30 to 90 / 10.

2. The high-performance emulsifier composition according to claim 1, characterized in that, The aforementioned diacid-based imidazoline amide is formed by amidation of plant fatty acids rich in unsaturated bonds and polyethylene polyamines under high temperature conditions.

3. The high-performance emulsifier composition according to claim 2, characterized in that, The aforementioned diacid-based imidazoline amide is prepared by reacting tall oil fatty acids rich in oleic acid, linoleic acid and rosin acid with diethylenetriamine under amidation and high temperature conditions, wherein the molar ratio of fatty acids to diethylenetriamine is greater than 2:

1.

4. The high-performance emulsifier composition according to claim 1, characterized in that, The N-hydroxyethylated aliphatic imidazoline is formed by amidation and cyclization under catalysis of natural plant fatty acids rich in unsaturated bonds and hydroxyethyl ethylenediamine; or by amidation and cyclization under catalysis of plant fatty acids and ethylenediamine to form aliphatic imidazoline, which is then further reacted with ethylene oxide to generate hydroxyethyl or hydroxyethyl-terminated polyoxyethylene groups on the nitrogen atom of the aliphatic imidazoline, thus forming N-hydroxyethylated aliphatic imidazoline.

5. The high-performance emulsifier composition of claim 4, characterized in that, The N-hydroxyethylated fatty acid imidazoline is formed by amidation and cyclization at high temperature of tall oil fatty acids rich in oleic acid, linoleic acid and rosin acid with hydroxyethyl ethylenediamine.

6. The high-performance emulsifier composition of claim 1, characterized in that, The maleic fatty acids mentioned above are generated by the synthesis of dienes and the reaction of maleic anhydride with plant fatty acids rich in unsaturated bonds under high temperature conditions.

7. The high-performance emulsifier composition of claim 6, characterized in that, The maleic fatty acid is prepared by reacting tall oil fatty acid rich in oleic acid, linoleic acid and rosin acid with maleic anhydride under high temperature conditions.

8. The high-performance emulsifier composition of claim 1, characterized in that, The alcohol ether is dipropylene glycol monomethyl ether.

9. The high-performance emulsifier composition of claim 1, characterized in that, The high-performance emulsifier composition comprises 75-80 parts by weight of bis-aliphatic imidazoline amide, 10-15 parts by weight of N-hydroxyethylated aliphatic imidazoline, and 10-15 parts by weight of maleic fatty acid.

10. The high-performance emulsifier composition of claim 1, characterized in that, In the high-performance emulsifier composition, the volume ratio of oil to alcohol ether polar solvent is 40 / 60 to 60 / 40.

11. The high-performance emulsifier composition of claim 10, characterized in that, In the high-performance emulsifier composition, the volume ratio of oil to alcohol ether polar solvent is 55 / 45.

12. The high-performance emulsifier composition of claim 1, characterized in that, In the high-performance emulsifier composition, the volume ratio of the active component to the solvent is 85 / 15.

13. A drilling fluid, characterized in that, The drilling fluid is an oil-based or synthetic-based drilling fluid, including the high-performance emulsifier composition according to any one of claims 1-12.

14. The drilling fluid of claim 13, characterized in that, It also includes base oil, aqueous phase, organophilic modified hancrocete, flow pattern modifier, polymer thickener, alkalinity modifier, activity control agent, organophilic modified humic acid filtration reducer, and weighting material.

15. The drilling fluid of claim 14, characterized in that, The ratio of the amount of the high-performance emulsifier composition added to the total volume of base oil and water phase in the drilling fluid is 50-80 g / L.

16. The drilling fluid of claim 14, characterized in that, The volume ratio of base oil to water phase is 85 / 15 to 95 / 5. Based on a total volume of 1L of base oil and water phase, the following are added: 25 to 50g of organic-modified hanketochtetite, 10 to 20g of flow pattern modifier, 5 to 15g of polymer thickener, 30 to 50g of alkalinity modifier, and 30 to 70g of organic-modified lignite filtration reducer.

17. The drilling fluid of claim 14, characterized in that, The base oil is diesel, mineral oil, or an environmentally friendly base oil with ultra-low aromatic content, which is artificially synthesized; the organophilic modified clay mineral is organophilic modified lithium aluminum silicate; the flow pattern regulator is polyamide fatty acid; the alkalinity regulator is calcium hydroxide or calcium oxide; and the polymeric thickener is a polyolefin block polymer.

18. The application of the drilling fluid according to any one of claims 13-17 in the development of deep oil and gas resources and unconventional oil and gas wells.

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