High-performance ultra-low-temperature drilling fluid system, preparation method and application thereof

Abstract

The application provides a high-performance ultra-low-temperature drilling fluid system and a preparation method and application thereof.The drilling fluid system comprises the following components in mass fraction: base fluid 80-90 parts, cutting agent 2-4 parts, flow pattern regulator 2-3 parts, wetting agent 1-2 parts and weighting agent 10-20 parts; wherein the preparation method of the wetting agent comprises the following steps: uniformly mixing polyoxyethylene ether and sodium fatty acid methyl ester sulfonate, heating, adding a catalyst, and then obtaining the wetting agent through reaction.The ultra-low-temperature drilling fluid system has excellent rheological properties and colloid dispersion properties under ultra-low-temperature conditions, and has excellent ultra-low-temperature resistance.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of high-performance ultra-low temperature drilling fluid system and its preparation method and application, belong to polar drilling technical field. BACKGROUND

[0002] The existing Antarctic drilling fluid has poor low-temperature rheological properties, low colloidal properties and insufficient low-temperature resistance, which seriously hinders the development of Antarctic scientific research.

[0003] Currently, scholars have also made some research in the development of ultra-low temperature drilling fluid. Chinese patent document CN103834370A discloses a kind of super-low temperature resistant calcium-based solid-free drilling fluid for drilling in frozen soil layer or cold region. The drilling fluid is prepared from water, calcium chloride, partially hydrolyzed polyacrylamide, tackifier and fluid loss additive, etc. The drilling fluid can be used for drilling operation under the condition of-5~ -35℃, and has good low-temperature rheological properties. Chinese patent document CN103146366A discloses a kind of two-component ester-based ultra-low temperature drilling fluid for polar regions. The main raw material of the drilling fluid is coconut oil heptyl ester derivative, but only the performance under-30℃ is tested. The above-mentioned inventions have the problems of insufficient super-low temperature resistance and poor low-temperature rheological properties.

[0004] Currently, there is almost no report on the high-performance ultra-low temperature (≤-55℃) drilling fluid system suitable for Antarctic regions. Therefore, it is urgent to develop a drilling fluid system with strong super-low temperature resistance, excellent rheological properties and colloidal properties under ultra-low temperature conditions, to improve the suspension and carrying efficiency of drilling fluid on cuttings during polar drilling, and thus improve the drilling efficiency. SUMMARY

[0005] In view of the deficiencies of the prior art, the present application provides a kind of high-performance ultra-low temperature drilling fluid system and its preparation method and application. The ultra-low temperature drilling fluid system of the present application has excellent rheological properties and colloidal dispersion properties under ultra-low temperature conditions, and excellent super-low temperature resistance. It can solve the problems of poor colloidal dispersion stability, difficulty in carrying rock and poor suspension during polar drilling.

[0006] To achieve the above-mentioned purpose, the technical scheme of the present application is as follows:

[0007] A kind of high-performance ultra-low temperature drilling fluid system, comprising the following mass fraction of components: base fluid 80~90 parts, cutting agent 2~4 parts, flow type regulator 2~3 parts, wetting agent 1~2 parts, weighting agent 10~20 parts;

[0008] The preparation method of the wetting agent comprises the following steps: mixing polyoxyethylene ether and sodium fatty acid methyl ester sulfonate uniformly, heating, adding catalyst, and then obtaining the wetting agent by reaction.

[0009] According to the application, preferably, the high-performance ultra-low temperature drilling fluid system comprises the following components in mass fraction: base fluid 80-85 parts, cutting agent 2-3 parts, flow pattern regulator 2 parts, wetting agent 1-2 parts, and weighting agent 15-20 parts.

[0010] According to the application, preferably, the base fluid is one of isododecane, aviation kerosene, polyhexene, or polyoctene, and the aviation kerosene is preferred. The polyhexene or polyoctene can be prepared according to the method in Chinese patent document CN114836180A.

[0011] According to the application, preferably, the cutting agent is single-layer silicate or organic bentonite for oil-based drilling fluid, and the single-layer silicate is preferred. The single-layer silicate can be commercially available, and is available from Shanghai Wanzhao Fine Chemical Co., Ltd. with model number WSG-H400. The organic bentonite for oil-based drilling fluid can be commercially available, and is available from Shanghai Wanzhao Fine Chemical Co., Ltd. with model number WSG-160F.

[0012] According to the application, the flow pattern regulator is prepared according to Chinese patent document CN115785917A. Preferably, the preparation method of the flow pattern regulator comprises the following steps:

[0013] (1) calcium-based bentonite and NaCl are added to deionized water, and stirred at 60-70℃ for 4-5h, then the solid is separated out, dried to constant weight at 60-70℃, ground, and sieved through a 180-220 mesh screen to obtain sodium-based bentonite; the mass of NaCl is 35-45% of the mass of calcium-based bentonite; the mass ratio of calcium-based bentonite to deionized water is 1:8-12;

[0014] (2) sodium-based bentonite is added to deionized water, and stirred at room temperature for 6-8h to obtain a sodium-based bentonite suspension; the concentration of the sodium-based bentonite suspension is 5-10wt%;

[0015] (3) methyltrioctylammonium chloride is dissolved in deionized water to obtain a modifier solution; the concentration of the modifier in the modifier solution is 0.5-2.5wt%;

[0016] (4) the pH of the sodium-based bentonite suspension is adjusted to 7-8 using sodium hydroxide, the modifier solution is added, and reacted at 60℃-80℃ for 0.5-1h; then silane coupling agent 3-aminopropylmethyldiethoxysilane is added, and reacted at 60℃-80℃ for 20-40min, the solid is separated out, dried to constant weight at 70-80℃, ground, and sieved through a 180-220 mesh screen to obtain the flow pattern regulator; the mass ratio of sodium-based bentonite in the sodium-based bentonite suspension to methyltrioctylammonium chloride in the modifier solution is 10:1-5; the mass of the silane coupling agent is 0.5-3 times the mass of methyltrioctylammonium chloride in the modifier solution.

[0017] According to the application, preferably, the polyoxyethylene ether is one of bisphenol A polyoxyethylene ether or isomeric decanol polyoxyethylene ether, preferably bisphenol A polyoxyethylene ether.

[0018] According to the application, preferably, the molar ratio of the polyoxyethylene ether and the sodium fatty acid methyl ester sulfonate is 1.05:(1.02-2.10), preferably 1.05:1.9.

[0019] According to the application, preferably, the temperature is raised to 70-90 DEG C.

[0020] According to the application, preferably, the catalyst is concentrated sulfuric acid with a mass concentration of 98 wt% or concentrated hydrochloric acid with a mass concentration of 36 wt%.

[0021] According to the application, preferably, the mass of the catalyst is 0.5%-1% of the total mass of the polyoxyethylene ether and the sodium fatty acid methyl ester sulfonate.

[0022] According to the application, preferably, the reaction temperature is 160 DEG C-175 DEG C, the reaction time is 5-6 h, and the reaction is carried out under the protection of a protective gas and stirring; preferably, the protective gas is nitrogen or argon, and the stirring rate is 350-380 r / min.

[0023] According to the application, preferably, the weighting agent is one of dichloromethane cleaning agent or dichloromonofluoroethane cleaning agent, preferably dichloromethane cleaning agent. The dichloromethane cleaning agent is commercially available, and is sold by Shanghai Ruiyi Environmental Protection Technology Co., Ltd. with the model EnaSolv MC azeotropic cleaning agent; the dichloromonofluoroethane cleaning agent is commercially available, and is sold by Shanghai Ruiyi Environmental Protection Technology Co., Ltd. with the model dichloromonofluoroethane HCFC-141B cleaning agent.

[0024] The preparation method of the high-performance ultra-low-temperature drilling fluid system comprises the following steps:

[0025] The weighting agent is added into the base fluid and dispersed fully, the wetting agent is added and dispersed fully, then the cuttability agent and the flow pattern regulator are added and dispersed fully, so that the high-performance ultra-low-temperature drilling fluid system is obtained.

[0026] The high-performance ultra-low-temperature drilling fluid system is applied in polar strata.

[0027] According to the application, preferably, the polar region is the South Pole.

[0028] The technical features and beneficial effects of the application are as follows:

[0029] 1. The preparation method is simple, and the obtained ultra-low-temperature drilling fluid system is safe, environmentally friendly and free of irritating odor.

[0030] 2、The ultra-low temperature drilling fluid of the present application adds a specific type of cut-adding agent to form a strong net structure in the drilling fluid, effectively improving the rheological properties of the drilling fluid at ultra-low temperatures and greatly improving the cut-carrying performance of the drilling fluid; the specific type of flow pattern regulator in the present application can make the drilling fluid have a relatively high viscosity ratio (10s -1 / 100s -1 ), thereby significantly improving the suspension performance of the drilling fluid.

[0031] 3、The wetting agent in the present application can significantly improve the colloidal stability of the drilling fluid at ultra-low temperatures (-55℃). In the preparation method of the wetting agent of the present application, the types and amounts of raw materials have an important influence on the performance of the wetting agent, and if they are not appropriate, the performance of the drilling fluid will be reduced.

[0032] 4、The raw material composition of the present application as a whole jointly achieves the excellent effect of the present application. The ultra-low temperature drilling fluid system of the present application can be used at ultra-low temperatures below -55℃ in the polar region; the colloidal rate under the condition of -55℃ is 83.2% or more, the dynamic shear force is 2.5 Pa or more, and the viscosity ratio (10s -1 / 100s -1 ) is 2.49 or more, having excellent ultra-low temperature colloidal properties and rheological properties. The obtained ultra-low temperature drilling fluid system has excellent comprehensive performance, can effectively carry cuttings, ensure wellbore cleaning, and improve drilling speed, thereby providing technical support for polar ultra-low temperature drilling engineering and having a broad application prospect. DETAILED DESCRIPTION

[0033] The present application will be further described below through specific examples, but is not limited thereto.

[0034] The experimental methods described in the examples are all conventional methods unless otherwise specified; the reagents and materials used are all available from commercial channels unless otherwise specified.

[0035] In the embodiment, the flow type regulator is prepared according to the method of Example 3 of Chinese patent document CN115785917A, and the specific steps are as follows: 16 g of calcium-based bentonite is added to 160 g of deionized water, and 6.4 g of NaCl is added at the same time, and stirred at 60°C for 4 h; after the above suspension is naturally cooled, the solid is separated by centrifugation, dried at 60°C to constant weight, ground and sieved through a 200 mesh sieve to obtain sodium-based bentonite; 10 g of sodium-based bentonite is weighed and dispersed in 115 g of deionized water, and stirred at room temperature for 8 h to fully hydrate to obtain a sodium-based bentonite suspension with a concentration of 8 wt%. 3 g of methyltrioctylammonium chloride is added to 197 mL of deionized water, and stirred to dissolve to obtain a 1.5 wt% modifier solution; the pH of the sodium-based bentonite suspension is adjusted to 8 using a 30 wt% sodium hydroxide aqueous solution, and the prepared bentonite suspension is poured into a three-necked flask, heated to 80°C during stirring, and then the modifier solution is slowly added to the bentonite suspension, and reacted at 80°C for 0.5 h. 3 g of silane coupling agent (3-aminopropylmethyldiethoxysilane) is added to the above system, and the reaction is continued at 80°C for 30 min; after the reaction is completed, the obtained reaction liquid is centrifuged, the obtained solid is dried at 80°C to constant weight, ground and sieved through a 200 mesh sieve to obtain the flow type regulator.

[0036] In the embodiment, the single-layer silicate is commercially available from Shanghai Wanzhao Fine Chemical Co., Ltd., with a model number of WSG-H400, a white flowable powder with an effective content of ≥99%; the oil-based drilling fluid organic bentonite is commercially available from Shanghai Wanzhao Fine Chemical Co., Ltd., with a model number of WSG-160F, a light cream-colored powder; the dichloromethane cleaning agent is commercially available from Shanghai Ruiyi Environmental Protection Technology Co., Ltd., with a model number of EnaSolv MC azeotropic cleaning agent, and its main component is dichloromethane; the dichloro-fluoroethane cleaning agent is commercially available from Shanghai Ruiyi Environmental Protection Technology Co., Ltd., with a model number of dichloro-fluoroethane HCFC-141B cleaning agent, and its main component is dichloro-fluoroethane. Bisphenol A polyoxyethylene ether is commercially available from Shandong Yousuo Chemical Technology Co., Ltd.; isomeric decanol polyoxyethylene ether is commercially available from Liaoning Kelong Fine Chemical Co., Ltd.

[0037] Example 1

[0038] A high-performance ultra-low-temperature drilling fluid system includes the following components in mass fractions: base fluid aviation kerosene 85 parts, cutting agent (single-layer silicate) 3 parts, flow type regulator 2 parts, wetting agent 2 parts, weighting agent (dichloromethane cleaning agent) 15 parts;

[0039] The preparation method of the wetting agent includes the following steps:

[0040] (1) Put the bisphenol A polyoxyethylene ether and sodium fatty acid methyl ester sulfonate into a three-necked flask, and pass nitrogen gas for 20 minutes to make the reaction system completely in an anaerobic state; the molar ratio of bisphenol A polyoxyethylene ether to sodium fatty acid methyl ester sulfonate is 1.05:1.9.

[0041] (2) When the above reaction system is warmed to 80°C, the catalyst (the catalyst is 98wt% concentrated sulfuric acid) is added; the mass of the catalyst is 0.8% of the total mass of bisphenol A polyoxyethylene ether and sodium fatty acid methyl ester sulfonate.

[0042] (3) The above reaction system is continuously warmed to 170°C, and is kept at a constant temperature for 5 hours under the conditions of a stirring rate of 360r / min and nitrogen protection.

[0043] (4) After the reaction is completed, the system is cooled to room temperature to obtain a wetting agent.

[0044] The preparation method of the above high-performance ultra-low-temperature drilling fluid system comprises the following steps:

[0045] (1) First, the base fluid is poured into a slurry cup, and the weighting agent is slowly added under the condition of stirring by a high-speed stirrer; the weighting agent is fully dispersed by stirring;

[0046] (2) The wetting agent is added to the above system, and the stirring is continued until the wetting agent is fully dispersed;

[0047] (3) The cuttability agent and the flow pattern regulator are continuously added in sequence, and are fully dispersed to prepare the high-performance ultra-low-temperature drilling fluid system.

[0048] Example 2

[0049] A high-performance ultra-low-temperature drilling fluid system comprises the following components in mass fractions: base fluid aviation kerosene 80 parts, cuttability agent (single-layer silicate) 3 parts, flow pattern regulator 2 parts, wetting agent 2 parts, and weighting agent (dichloromethane cleaning agent) 20 parts.

[0050] The preparation method of the wetting agent is the same as that in Example 1.

[0051] The preparation method of the above high-performance ultra-low-temperature drilling fluid system is the same as that in Example 1.

[0052] Example 3

[0053] A high-performance ultra-low-temperature drilling fluid system is as described in Example 1, except that the amount of the cuttability agent (single-layer silicate) is 2 parts, and the other raw material compositions are the same as those in Example 1.

[0054] The preparation method of the wetting agent is the same as that in Example 1.

[0055] The preparation method of the above high-performance ultra-low-temperature drilling fluid system is the same as that in Example 1.

[0056] Example 4

[0057] A high performance ultra-low temperature drilling fluid system as described in Example 1, except that the wetting agent is added in an amount of 1 part and the other raw materials are the same as in Example 1.

[0058] The wetting agent is prepared according to the method of Example 1.

[0059] The high performance ultra-low temperature drilling fluid system described above is prepared according to the method of Example 1.

[0060] Example 5

[0061] A high performance ultra-low temperature drilling fluid system as described in Example 1, except that the polyoxyethylene ether is isomeric decanol polyoxyethylene ether and the other raw materials are the same as in Example 1.

[0062] The wetting agent is prepared according to the method of Example 1.

[0063] The high performance ultra-low temperature drilling fluid system described above is prepared according to the method of Example 1.

[0064] Example 6

[0065] A high performance ultra-low temperature drilling fluid system as described in Example 1, except that the base fluid is isomeric dodecane and the other raw materials are the same as in Example 1.

[0066] The wetting agent is prepared according to the method of Example 1.

[0067] The high performance ultra-low temperature drilling fluid system described above is prepared according to the method of Example 1.

[0068] Example 7

[0069] A high performance ultra-low temperature drilling fluid system as described in Example 1, except that the cuttmg agent is an organic bentonite for oil-based drilling fluids and the other raw materials are the same as in Example 1.

[0070] The wetting agent is prepared according to the method of Example 1.

[0071] The high performance ultra-low temperature drilling fluid system described above is prepared according to the method of Example 1.

[0072] Example 8

[0073] A high performance ultra-low temperature drilling fluid system as described in Example 1, except that the weighting agent is dichloromonofluoroethane cleaning agent and the other raw materials are the same as in Example 1.

[0074] The wetting agent is prepared according to the method of Example 1.

[0075] The high performance ultra-low temperature drilling fluid system described above is prepared according to the method of Example 1.

[0076] Comparative Example 1

[0077] A drilling fluid system as described in Example 1 except that the base fluid is increased to 75 parts, the weighting agent (dichloromethane scavenger) is increased to 25 parts, and the other ingredients are the same as in Example 1.

[0078] The wetting agent is prepared as described in Example 1.

[0079] The drilling fluid system is prepared as described in Example 1.

[0080] Comparative Example 2

[0081] A drilling fluid system as described in Example 1 except that the viscosifier (monolayer silicate) is increased to 1 part, and the other ingredients are the same as in Example 1.

[0082] The wetting agent is prepared as described in Example 1.

[0083] The drilling fluid system is prepared as described in Example 1.

[0084] Comparative Example 3

[0085] A drilling fluid system as described in Example 1 except that the wetting agent is changed to dioctadecyl dimethyl ammonium chloride, and the other ingredients are the same as in Example 1.

[0086] The drilling fluid system is prepared as described in Example 1.

[0087] Comparative Example 4

[0088] A drilling fluid system as described in Example 1 except that the base fluid is changed to butyl acetate, and the other ingredients are the same as in Example 1.

[0089] The wetting agent is prepared as described in Example 1.

[0090] The drilling fluid system is prepared as described in Example 1.

[0091] Comparative Example 5

[0092] A drilling fluid system as described in Example 1 except that in the preparation of the wetting agent, the sodium fatty acid methyl ester sulfonate monomer is changed to sodium fatty acid methyl ester ethoxylate sulfonate, and the other steps and conditions in the preparation of the wetting agent are the same as in Example 1; and the other ingredients are the same as in Example 1.

[0093] The drilling fluid system is prepared as described in Example 1.

[0094] Comparative Example 6

[0095] A drilling fluid system as described in Example 1, except that in the preparation of the wetting agent, the molar ratio of polyoxyethylene ether to sodium fatty acid methyl ester sulfonate is 2:1, and the other steps and conditions of the preparation of the wetting agent are the same as in Example 1; and the other raw material compositions are the same as in Example 1.

[0096] A method for preparing the drilling fluid system as described above is the same as in Example 1.

[0097] Test Example 1

[0098] The drilling fluid systems prepared in the examples and comparative examples are tested for performance at -55℃, and the test results are shown in Table 1.

[0099] Test Method:

[0100] Gelation rate test: a certain amount of prepared drilling fluid is poured into a colorimetric tube, and then the colorimetric tube is placed in a low-temperature constant-temperature oven (-55℃) for 16h, and the gelation rate is calculated, Gelation rate = (lower volume / total volume) * 100%.

[0101] Rheological property test:

[0102] 1) Viscosity and dynamic shear force test: the prepared drilling fluid is poured into a test slurry cup, and the low-temperature rheometer is used to test the readings at 600r, 300r and 6r at -55℃, and then the relevant rheological parameters such as apparent viscosity, plastic viscosity and dynamic shear force are calculated.

[0103] 2) Test of the ratio of low shear rate (10s -1 ) viscosity to high shear rate (100s -1 ) viscosity: the prepared drilling fluid is frozen in an ultra-low-temperature constant-temperature oven (-55℃) for 16h, and then the low shear rate viscosity and the high shear rate viscosity are tested by a Hake rheometer, and then the ratio is calculated.

[0104] Table 1 Performance test of the drilling fluid system at -55℃

[0105]

[0106] As can be seen from the data in Table 1, the ultra-low-temperature drilling fluid system prepared by the present application exhibits good lifting performance at -55℃, the lifting effect is remarkable, the viscosity increase is controllable, and the ultra-low-temperature colloidal dispersion performance of the drilling fluid is excellent. The dynamic shear force at -55℃ can reach more than 2.5Pa, and the gelation rate after standing for 16h can still reach more than 83.2%. It shows that the ultra-low-temperature drilling fluid system has excellent comprehensive performance under ultra-low-temperature conditions, and can meet the technical needs of polar drilling.

[0107] In summary, the ultra-low-temperature drilling fluid system of the present application can meet the needs of polar drilling.

[0108] The above describes the preferred embodiments of the present application in detail, but the present application is not limited to the specific details in the above-described embodiments, and various simple modifications can be made to the technical solutions of the present application within the technical concept of the present application, and these simple modifications all belong to the protection scope of the present application.

[0109] In addition, it should be noted that each specific technical feature described in the above-described specific embodiments can be combined in any appropriate manner without contradiction, and in order to avoid unnecessary repetition, the present application will not further describe various possible combinations.

[0110] In addition, various different embodiments of the present application can also be combined in any manner, as long as it does not deviate from the idea of the present application, and it should also be considered as disclosed by the present application.

Claims

1. A drilling fluid system, characterized by, The drilling fluid system comprises the following components in mass fraction: base fluid 80-90 parts, cutting agent 2-4 parts, flow pattern modifier 2-3 parts, wetting agent 1-2 parts, and weighting agent 10-20 parts. The preparation method of the wetting agent comprises the following steps: uniformly mixing polyoxyethylene ether and sodium fatty acid methyl ester sulfonate, heating, adding a catalyst, and then obtaining the wetting agent through reaction. The base fluid is one of isododecane, aviation kerosene, polyhexene, or polyoctene; and the cutting agent is single-layer silicate or organic bentonite for oil-based drilling fluid.

2. The drilling fluid system of claim 1, wherein, The drilling fluid system comprises the following components in mass fraction: base fluid 80-85 parts, cutting agent 2-3 parts, flow pattern modifier 2 parts, wetting agent 1-2 parts, and weighting agent 15-20 parts.

3. The drilling fluid system of claim 1, wherein, The base fluid is aviation kerosene.

4. The drilling fluid system of claim 1, wherein, The cutting agent is single-layer silicate.

5. The drilling fluid system of claim 1, wherein, The polyoxyethylene ether is one of bisphenol A polyoxyethylene ether or isomeric decanol polyoxyethylene ether.

6. The drilling fluid system of claim 1, wherein, The molar ratio of the polyoxyethylene ether to sodium fatty acid methyl ester sulfonate is 1.05: (1.02-2.10).

7. The drilling fluid system of claim 1, wherein, One or more of the following conditions are included: i. heating to a temperature of 70-90°C; ii. the catalyst is concentrated sulfuric acid with a mass concentration of 98wt% or concentrated hydrochloric acid with a mass concentration of 36wt%; iii. the mass of the catalyst is 0.5%-1% of the total mass of the polyoxyethylene ether and sodium fatty acid methyl ester sulfonate; iv. the reaction temperature is 160-175°C, the reaction time is 5-6h, and the reaction is carried out under the protection of a protective gas and stirring; the protective gas is nitrogen or argon, and the stirring rate is 350-380 r / min.

8. The drilling fluid system of claim 1, wherein, The weighting agent is one of dichloromethane cleaning agent or dichloromonofluoroethane cleaning agent.

9. The preparation method of the drilling fluid system according to any one of claims 1-8, comprising the following steps: adding the weighting agent to the base fluid and fully dispersing; adding the wetting agent and fully dispersing; and then adding the cutting agent and the flow pattern modifier and fully dispersing to obtain the drilling fluid system.

10. The drilling fluid system according to any one of claims 1-8, applied in polar strata.

11. Use according to claim 10, characterized in that, The polar region is the South Pole.

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