Oil removing agent for biomass synthesis based drilling fluid and preparation method of oil removing agent

Abstract

The invention provides an oil removing agent for a biomass synthesis-based drilling fluid. The oil removing agent comprises the following components in parts by weight: 2-15 parts of a penetrating agent; 5-30 parts by weight of a complexing agent; 1-10 parts by weight of a dissolution promoter; 8-30 parts by weight of an emulsifier; 100 parts by weight of water; the penetrating agent is a sulfosuccinate salt and / or a polyoxyethylene ether compound; the complexing agent is organic phosphonate and / or hydroxy carboxylate; the dissolution promoter is dearomatized solvent oil; the emulsifier is a betaine zwitterionic surfactant. Compared with the prior art, the oil cleaning agent for the biomass synthesis-based drilling fluid adopts the components with specific contents, and the components have good interaction, so that the obtained oil cleaning agent for the biomass synthesis-based drilling fluid has a good cleaning effect, and meanwhile, due to the fact that the preferred raw materials do not contain aromatic hydrocarbon, the oil cleaning agent has biodegradability and is safe to the environment; environmental protection is facilitated; the preparation method of the oil-based drilling fluid oil cleaning agent is simple, mild in condition and suitable for large-scale industrial production.

Description

Technical Field

[0001] The invention belongs to the technical field of oilfield chemistry, and in particular relates to an oil cleaning agent for biomass synthetic-based drilling fluid, a preparation method and application thereof. Background Art

[0002] In recent years, with the continuous deepening of oil and gas exploration and development, the geological conditions encountered during drilling have become increasingly complex. At the same time, the exploration and development of shale oil and gas resources have placed higher and higher requirements on drilling fluids. Oil-based drilling fluids have been widely used as an effective method to solve difficult and complex problems and ensure the smooth drilling of shale oil and gas formations. However, the base oil used in oil-based drilling fluids is diesel or white oil, which contains aromatic hydrocarbons, which is unsafe for personal safety and the environment, and its application in some environmentally sensitive areas has been restricted.

[0003] Biomass synthetic drilling fluid has gradually gained attention due to its advantages such as green environmental protection and biodegradability, in order to replace diesel (white) oil-based drilling fluid. Biomass synthetic drilling fluid uses biomass synthetic oil as the base oil. Biomass synthetic oil includes saturated long-chain fatty groups and alkyl ether groups in structure, and does not contain unsaturated bonds (such as ester bonds and carbon-carbon double bonds) and aromatic hydrocarbons. This biomass synthetic oil has good biodegradability and is a kind of green and non-toxic product. It has no irritating effect on the human body and the environment itself and after decomposition, and has good ecological safety. However, biomass synthetic drilling fluid and its filter cake adhere to the well wall and are difficult to remove, resulting in poor bonding quality of the cement slurry interface, affecting the cementing quality. Therefore, effectively removing the adhesion of biomass synthetic drilling fluid on the well wall is an important technical means to ensure the quality of cementing.

[0004] In the prior art, there is no special oil-cleaning agent for biomass synthetic drilling fluid, and the oil-cleaning agent for oil-based drilling fluid is used. There are many oil-cleaning agents used at home and abroad, but they all have the problems of complex composition, poor flushing efficiency, and inability to completely seal the two interfaces. Therefore, it is of great strategic significance to study oil-cleaning agents with good environmental protection, biodegradability, high flushing efficiency, and wide application range to provide technical support for oil drilling. Summary of the invention

[0005] In view of this, the technical problem to be solved by the present invention is to provide a biomass synthetic-based drilling fluid oil cleaning agent with good flushing effect, and a preparation method and application thereof.

[0006] The present invention provides a biomass synthetic-based oil cleaning agent for drilling fluid, comprising:

[0007]

[0008] The penetrant is selected from sulfosuccinate salts and / or polyoxyethylene ether compounds;

[0009] The complexing agent is selected from organic phosphonates and / or hydroxycarboxylates;

[0010] The solubilizing agent is selected from dearomatized solvent oil;

[0011] The emulsifier is selected from betaine zwitterionic surfactants.

[0012] Preferably, the penetrant is selected from one or more of di-sec-octyl sulfosuccinate sodium salt and / or isomeric tridecanol polyoxyethylene ether.

[0013] Preferably, the complexing agent is selected from one or more of ethylenediaminetetramethylenephosphate, diethylenetriaminepenta(methylenephosphonate), citric acid, sodium gluconate and sodium alginate.

[0014] Preferably, the solubilizing agent is selected from one or more of D60, D80 and D100.

[0015] Preferably, the emulsifier is selected from one or more of cocamidopropyl hydroxysulfonyl betaine, lauramidopropyl betaine and lauramidopropyl hydroxysulfonyl betaine.

[0016] The present invention also provides a method for preparing the above-mentioned biomass synthetic-based oil clearing agent for drilling fluid, comprising the following steps:

[0017] S) mixing the penetrant, the complexing agent, the solubilizing agent, the emulsifier and water, and reacting them to obtain the oil clearing agent for the biomass synthetic-based drilling fluid.

[0018] Preferably, the step S) is specifically:

[0019] The penetrant is mixed with water and stirred for the first time, then a complexing agent is added and stirred for the second time, a dissolving agent is added and stirred for the third time, and an emulsifier is added and stirred for the fourth time. After the reaction, an oil clearing agent for biomass synthetic-based drilling fluid is obtained.

[0020] Preferably, the rotation speeds of the first stirring, the second stirring, the third stirring and the fourth stirring are each independently 300 to 1000 r / min; the time of the first stirring, the second stirring, the third stirring and the fourth stirring are each independently 5 to 20 min; the temperature of the reaction is 30° C. to 50° C.; and the reaction time is 0.5 to 2 h.

[0021] The present invention also provides a method for using the above-mentioned biomass synthetic-based drilling fluid oil clearing agent, comprising: mixing the biomass synthetic-based drilling fluid oil clearing agent with cementing cleaning fluid.

[0022] Preferably, the mass of the biomass synthetic-based oil cleaning agent for drilling fluid is 10% to 25% of the mass of the cementing cleaning fluid.

[0023] The present invention provides a biomass synthetic drilling fluid oil clearing agent, comprising: 2 to 15 parts by weight of a penetrant; 5 to 30 parts by weight of a complexing agent; 1 to 10 parts by weight of a solubilizing agent; 8 to 30 parts by weight of an emulsifier; and 100 parts by weight of water; the penetrant is a sulfosuccinate salt and / or a polyoxyethylene ether compound; the complexing agent is an organic phosphonate and / or a hydroxycarboxylate; the solubilizing agent is a dearomatized solvent oil; and the emulsifier is a betaine zwitterionic surfactant. Compared with the prior art, the biomass synthetic drilling fluid oil clearing agent of the present invention uses components with specific contents, and the components have good interactions with each other, so that the obtained biomass synthetic drilling fluid oil clearing agent has a good cleaning effect. At the same time, because the preferred raw material does not contain aromatic hydrocarbons, it is biodegradable, safe for the environment, and beneficial to environmental protection; and the preparation method of the oil-based drilling fluid oil clearing agent is simple, the conditions are mild, and it is suitable for large-scale industrial production.

[0024] The experimental results show that the biomass synthetic drilling fluid oil clearing agent provided by the present invention has a good flushing effect and is suitable for oils with a density of 0.8 to 2.3 g / cm 3 The biomass synthetic-based drilling fluid and the formation temperature of 120℃~180℃ have good environmental performance. DETAILED DESCRIPTION

[0025] 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.

[0026] The present invention provides a biomass synthetic-based oil cleaning agent for drilling fluid, comprising:

[0027]

[0028] The penetrant is a sulfosuccinate salt and / or a polyoxyethylene ether compound;

[0029] The complexing agent is an organic phosphonate and / or a hydroxycarboxylate;

[0030] The solubilizing agent is dearomatized solvent oil;

[0031] The emulsifier is a betaine zwitterionic surfactant.

[0032] According to the present invention, the content of the penetrant in the oil clearing agent for biomass synthetic-based drilling fluid is preferably 5 to 12 parts by weight, more preferably 5 to 10 parts by weight; in some embodiments provided by the present invention, the content of the penetrant in the oil clearing agent for biomass synthetic-based drilling fluid is specifically 5 parts by weight, 10 parts by weight, 8 parts by weight, 6 parts by weight or 7 parts by weight; the penetrant is a sulfosuccinate salt and / or a polyoxyethylene ether compound which is a nonionic or anionic surfactant, has a rapid penetration effect, and is beneficial to destroying the oil film and filter cake of the well wall; in the present invention, the sulfosuccinate salt is preferably sodium salt of di-sec-octyl sulfosuccinate; the polyoxyethylene ether compound is preferably isomeric tridecyl alcohol polyoxyethylene ether.

[0033] According to the present invention, the content of the complexing agent in the oil clearing agent for biomass synthetic drilling fluid is preferably 8 to 25 parts by weight, more preferably 10 to 20 parts by weight; in some embodiments provided by the present invention, the content of the complexing agent in the oil clearing agent for biomass synthetic drilling fluid is specifically 10 parts by weight, 12 parts by weight, 18 parts by weight, 15 parts by weight or 20 parts by weight; the complexing agent is an organic phosphonate and / or a hydroxycarboxylate; the organic phosphonate is preferably sodium ethylenediaminetetramethylenephosphate and / or diethylenetriaminepenta(methylenephosphonate); the hydroxycarboxylate is preferably one or more of citric acid, sodium gluconate and sodium alginate; the complexing agent can combine with metal ions in biomass synthetic drilling fluid and formation fluid, promote the destruction of the filter cake and the separation of the destroyed oil film and filter cake from the well wall, and no longer re-adhere to the well wall, thereby improving the cleaning effect.

[0034] According to the present invention, the content of the solubilizer in the oil clearing agent for biomass synthetic-based drilling fluid is preferably 2 to 8 parts by weight, more preferably 2 to 5 parts by weight; in some embodiments provided by the present invention, the content of the solubilizer in the oil clearing agent for biomass synthetic-based drilling fluid is specifically 2 parts by weight, 3 parts by weight, 4 parts by weight or 5 parts by weight; the solubilizer is dearomatized solvent oil, which has an alkane structure, similar to the base fluid structure of the biomass synthetic-based drilling fluid, and can disperse the destroyed oil film in the flushing fluid, and further separate the oil film on the well wall from the well wall and disperse in the flushing fluid, which has the effect of stabilizing the emulsion droplets; in the present invention, the solubilizer is preferably one or more of D60, D80 and D100.

[0035] According to the present invention, the content of the emulsifier in the oil clearing agent for biomass synthetic-based drilling fluid is preferably 10 to 25 parts by weight, more preferably 10 to 20 parts by weight; in some embodiments provided by the present invention, the content of the emulsifier in the oil clearing agent for biomass synthetic-based drilling fluid is specifically 10 parts by weight, 14 parts by weight, 18 parts by weight, 12 parts by weight or 20 parts by weight; the emulsifier is a betaine-based zwitterionic surfactant, which has the effect of producing oil-in-water, and can emulsify the oil film and filter cake entering the flushing fluid to form a stable emulsion; in the present invention, the emulsifier is selected from one or more of cocoamidopropyl hydroxysulfonyl betaine, lauroamidopropyl betaine and lauroamidopropyl hydroxysulfonyl betaine.

[0036] The biomass synthetic-based drilling fluid oil clearing agent of the present invention adopts components with specific contents, and the components have good interaction with each other, so that the obtained biomass synthetic-based drilling fluid oil clearing agent has good cleaning effect, and at the same time, because the preferred raw materials do not contain aromatic hydrocarbons, they are biodegradable, safe for the environment, and beneficial to environmental protection; and the preparation method of the oil-based drilling fluid oil clearing agent is simple, the conditions are mild, and it is suitable for large-scale industrial production.

[0037] The present invention also provides a method for preparing the above-mentioned biomass synthetic-based drilling fluid oil clearing agent, comprising the following steps: S) mixing a penetrant, a complexing agent, a solubilizing agent, an emulsifier and water, and obtaining the biomass synthetic-based drilling fluid oil clearing agent after reaction.

[0038] The present invention has no special restrictions on the sources of all raw materials, and any raw materials available on the market can be used; the contents and types of the penetrant, complexing agent, solubilizer and emulsifier are the same as those described above and will not be described in detail here.

[0039] The penetrant, complexing agent, solubilizer, emulsifier and water are mixed; the mixing method is a method well known to those skilled in the art and is not particularly limited; in the present invention, the mixing is preferably carried out by stirring; the mixing speed is preferably 300-1000 r / min, more preferably 400-800 r / min, more preferably 500-700 r / min, and most preferably 600 r / min; in the present invention, it is further preferred that the mixing is carried out according to the following steps: the penetrant is mixed with water for the first stirring, the complexing agent is added for the second stirring, and the mixing is carried out by stirring. The dissolution agent is stirred for the third time, and the emulsifier is added for the fourth stirring; the rotation speeds of the first stirring, the second stirring, the third stirring and the fourth stirring are each independently preferably 300-1000r / min, more preferably 400-800r / min, more preferably 500-700r / min, and most preferably 600r / min; the time of the first stirring, the second stirring, the third stirring and the fourth stirring is each independently preferably 5-20min, more preferably 8-15min, more preferably 8-12min, and most preferably 10min.

[0040] After mixing, reacting to obtain a biomass synthetic-based drilling fluid oil clearing agent; the reaction is preferably carried out under stirring; the stirring speed is preferably 300-1000r / min, more preferably 400-800r / min, more preferably 500-700r / min, and most preferably 500-600r / min; the reaction temperature is preferably 30°C-50°C; in some embodiments provided by the present invention, the reaction temperature is specifically 35°C, 30°C, 40°C or 50°C; the reaction time is preferably 0.5-2h, more preferably 0.8-1.5h, and more preferably 1-1.2h.

[0041] The present invention also provides an application of the above-mentioned oil clearing agent for biomass synthetic-based drilling fluid in flushing biomass synthetic-based drilling fluid.

[0042] The density of the biomass synthetic drilling fluid is preferably 0.8 to 2.3 g / cm 3 ; The temperature of the biomass synthetic based drilling fluid is preferably 120°C to 180°C.

[0043] The present invention also provides a method for using the biomass synthetic-based drilling fluid oil clearing agent, comprising: mixing the biomass synthetic-based drilling fluid oil clearing agent with a cementing cleaning fluid.

[0044] The mass of the biomass synthetic-based oil cleaning agent for drilling fluid is preferably 10% to 25% of the mass of the cementing cleaning fluid, and more preferably 10% to 20%.

[0045] The cementing flushing fluid can be any cementing flushing fluid well known to those skilled in the art without any special limitation. In the embodiment provided by the present invention, the cementing flushing fluid specifically includes water and a suspending agent; the mass of the suspending agent is preferably 0.5% to 5% of the mass of the cementing flushing fluid, more preferably 1% to 3%, and even more preferably 2%.

[0046] In order to further illustrate the present invention, the following describes in detail a biomass synthetic-based oil cleaning agent for drilling fluid, a preparation method thereof and an application thereof in combination with embodiments.

[0047] The reagents used in the following examples are all commercially available; the penetrant used in the examples is A1 sodium salt of dioctyl sulfosuccinate or A2 isomeric tridecanol polyoxyethylene ether (E-1310) provided by Nantong Yixun Chemical Technology Co., Ltd.; the complexing agent is B1 sodium ethylenediaminetetramethylene phosphate and B2 sodium diethylenetriaminepenta(methylenephosphonic acid) provided by Zaozhuang Ziyang Environmental Protection Technology Co., Ltd.; B3 citric acid and B4 sodium gluconate provided by Suzhou Changhong Chemical Co., Ltd.; B5 sodium alginate provided by Jiangsu Runfeng Synthetic Technology Co., Ltd.; the solubilizing agent is C1 D60, C2 D80, and C3 D100 provided by Shandong Shengda Chemical Co., Ltd.; the emulsifier is D1 cocamidopropyl hydroxysulfobetaine and D2 lauramide propyl betaine provided by Linyi Lusen Chemical Co., Ltd.

[0048] Example 1

[0049] (1) Add 5 g of Al to 100 g of water and stir at a stirring rate of 600 r / min for 10 min.

[0050] (2) Add 10 g of B1 to the liquid obtained in step (1), and stir at a stirring rate of 600 r / min for 10 min.

[0051] (3) Add 2 g of C1 to the liquid obtained in step (2) and stir at a stirring rate of 600 r / min for 10 min.

[0052] (4) Add 10 g of D1 to the liquid obtained in step (3) and stir at a stirring rate of 600 r / min for 10 min.

[0053] (5) The solution obtained in step (4) was heated to 35° C., the reaction stirring rate was 500 r / min, the reaction time was 1.0 h, and a biomass synthetic-based oil clearing agent for drilling fluid was obtained.

[0054] Example 2

[0055] (1) Add 10 g of A1 to 100 g of water and stir at a stirring rate of 600 r / min for 10 min.

[0056] (2) Add 12 g of B2 to the liquid obtained in step (1), and stir at a stirring rate of 600 r / min for 10 min.

[0057] (3) Add 2 g of C2 to the liquid obtained in step (2) and stir at a stirring rate of 600 r / min for 10 min.

[0058] (4) Add 10 g of D2 to the liquid obtained in step (3) and stir at a stirring rate of 600 r / min for 10 min.

[0059] (5) The obtained solution was heated to 30° C., the reaction stirring rate was 500 r / min, the reaction time was 1.0 h, and a biomass synthetic-based oil clearing agent for drilling fluid was obtained.

[0060] Example 3

[0061] (1) Add 8 g of A2 to 100 g of water and stir at a stirring rate of 600 r / min for 10 min.

[0062] (2) Add 18 g of B3 to the liquid obtained in step (1), and stir at a stirring rate of 600 r / min for 10 min.

[0063] (3) Add 3 g of C3 to the liquid obtained in step (2) and stir at a stirring rate of 600 r / min for 10 min.

[0064] (4) Add 14 g of D2 to the liquid obtained in step (3) and stir at a stirring rate of 600 r / min for 10 min.

[0065] (5) The solution obtained in step (4) is heated to 40° C., the reaction stirring rate is 500 r / min, and the reaction time is 1.0 h to obtain a biomass synthetic-based oil clearing agent for drilling fluid.

[0066] Example 4

[0067] (1) Add 6 g of A2 to 100 g of water and stir at a stirring rate of 600 r / min for 10 min.

[0068] (2) Add 15 g of B4 to the liquid obtained in step (1), and stir at a stirring rate of 600 r / min for 10 min.

[0069] (3) Add 4 g of Cl to the liquid obtained in step (2) and stir at a stirring rate of 600 r / min for 10 min.

[0070] (4) Add 18 g of D1 to the liquid obtained in step (3), and stir at a stirring rate of 600 r / min for 10 min.

[0071] (5) The solution obtained in step (4) was heated to 50° C., the reaction stirring rate was 500 r / min, the reaction time was 1.0 h, and a biomass synthetic-based oil clearing agent for drilling fluid was obtained.

[0072] Example 5

[0073] (1) Add 10 g of A1 to 100 g of water and stir at a stirring rate of 600 r / min for 10 min.

[0074] (2) Add 20 g of B5 to the liquid obtained in step (1), and stir at a stirring rate of 600 r / min for 10 min.

[0075] (3) Add 4 g of C2 to the liquid obtained in step (2) and stir at a stirring rate of 600 r / min for 10 min.

[0076] (4) Add 12 g of D1 to the liquid obtained in step (3), and stir at a stirring rate of 600 r / min for 10 min.

[0077] (5) The solution obtained in step (4) is heated to 40° C., the reaction stirring rate is 500 r / min, and the reaction time is 1.0 h to obtain a biomass synthetic-based oil clearing agent for drilling fluid.

[0078] Example 6

[0079] (1) Add 8 g of A2 to 100 g of water and stir at a stirring rate of 600 r / min for 10 min.

[0080] (2) Add 15 g of B2 to the liquid obtained in step (1), and stir at a stirring rate of 600 r / min for 10 min.

[0081] (3) Add 3 g of C1 to the liquid obtained in step (2) and stir at a stirring rate of 600 r / min for 10 min.

[0082] (4) Add 18 g of D2 to the liquid obtained in step (3) and stir at a stirring rate of 600 r / min for 10 min.

[0083] (5) The solution obtained in step (4) was heated to 30° C., the reaction stirring rate was 500 r / min, the reaction time was 1.0 h, and a biomass synthetic-based oil clearing agent for drilling fluid was obtained.

[0084] Example 7

[0085] (1) Add 7 g of A2 to 100 g of water and stir at a stirring rate of 600 r / min for 10 min.

[0086] (2) Add 12 g of B1 to the liquid obtained in step (1), and stir at a stirring rate of 600 r / min for 10 min.

[0087] (3) Add 5 g of C3 to the liquid obtained in step (2), and stir at a stirring rate of 600 r / min for 10 min.

[0088] (4) Add 20 g of D1 to the liquid obtained in step (3), and stir at a stirring rate of 600 r / min for 10 min.

[0089] (5) The solution obtained in step (4) was heated to 50° C., the reaction stirring rate was 500 r / min, the reaction time was 1.0 h, and a biomass synthetic-based oil clearing agent for drilling fluid was obtained.

[0090] The performance of the biomass synthetic-based drilling fluid oil cleaning agents prepared in Examples 1 to 7 was evaluated.

[0091] Evaluation method for flushing efficiency of oil cleaning agent for biomass synthetic drilling fluid:

[0092] (1) Cut 80-grit sandpaper according to the circumference and height of the outer cylinder of the six-speed rotary viscometer, fix it on the surface of the outer cylinder, weigh it, and record its mass as m1.

[0093] (2) Immerse the outer cylinder of the six-speed rotary viscometer in step (1) into the biomass synthetic-based drilling fluid so that the liquid level just covers the upper edge of the sandpaper. Soak for 5 minutes, take out and weigh it, and record it as m2.

[0094] (3) Use biomass synthetic drilling fluid oil cleaning agent to prepare flushing fluid.

[0095] (4) Install the outer cylinder with biomass synthetic drilling fluid on the six-speed rotating viscometer, inject the flushing liquid into the six-speed rotating viscosity sample cup to the scale line, move the bottom frame so that the flushing liquid level coincides with the scale line on the outer cylinder, rotate at a speed of 300 r / min for 8 min, remove the outer cylinder, place it in a 105 °C oven for 2 h, and weigh its mass again, recorded as m3.

[0096] (5) Flushing efficiency calculation formula:

[0097] W = (m2-m3) × 100 / (m2-m1) (1)

[0098] Where: w—is the flushing efficiency, %;

[0099] m1—Total mass of the outer cylinder and sandpaper before soaking in biomass synthetic drilling fluid, in g;

[0100] m2—mass of biomass synthetic drilling fluid after immersion for 5 minutes, in g;

[0101] m3—The mass after being rinsed with flushing liquid for 8 minutes and dried for 2 hours, in grams.

[0102] Flushing efficiency of biomass synthetic drilling fluid oil cleaning agents prepared in Examples 1 to 7

[0103] Preparation method of flushing fluid: Take 400mL of clean water, add 8g of suspending agent (Puyang Minghua Chemical Co., Ltd., model M71S), and then add 40-80g of oil clearing agent of Examples 1-7 respectively, and stir for 10min under high-speed stirring condition of 6000r / min. According to the above flushing efficiency evaluation method, the experiment was carried out, and the biomass synthetic-based drilling fluid density used for soaking the outer cylinder of the six-speed rotating viscometer was 2.0g / cm 3 (Example 8 in the Chinese patent publication number CN 110872493 A) The experimental results of Examples 1 to 7 are shown in Table 1.

[0104] Table 1 Flushing efficiency of the oil cleaning agent for biomass synthetic drilling fluid prepared in Examples 1 to 7

[0105] Example Added amount, g Flushing efficiency, % 1 40 92.5 2 60 93.8 3 60 93.6 4 60 95.7 5 60 98.6 6 72 98.4 7 80 96.2

[0106] As shown in Table 1, the oil clearing agents prepared in Examples 1 to 7 of the present invention can meet the requirements of density up to 2.0 g / cm 3 The flushing efficiency of biomass synthetic-based drilling fluid exceeds 90%, and it has a good flushing effect.

[0107] The performance evaluation of the flushing efficiency of different amounts of the oil-clearing agent prepared in Example 5 was performed: 400 mL of clean water was added with 8 g of suspending agent (Puyang Minghua Chemical Co., Ltd., model M71S), and different masses of the oil-clearing agent prepared in Example 5 were added respectively, and stirred for 10 minutes under a high-speed stirring condition of 6000 r / min. The experiment was carried out according to the above flushing efficiency evaluation method, and the results were shown in Table 2. The biomass synthetic-based drilling fluid used for soaking the outer cylinder of the six-speed rotating viscometer was prepared in Example 8 of the Chinese patent with publication number CN 110872493A. The density of the biomass synthetic-based drilling fluid was obtained by adjusting the amount of barite added to be 0.8-2.3 g / cm 3 .

[0108] Table 2 Flushing efficiency of different addition amounts in Example 5

[0109]

[0110]

[0111] From the results in Table 2, it can be seen that the biomass synthetic-based drilling fluid oil clearing agent prepared in Example 5 of the present invention has a good effect on the density of 0.8-2.3 g / cm 3The biomass synthetic-based drilling fluids all have good flushing effects, and the flushing efficiency exceeds 90%.

[0112] The flushing efficiency of the biomass synthetic-based drilling fluid oil clearing agent prepared in Example 5 under different temperature conditions was evaluated: 400 mL of clean water was added with 8 g of suspending agent (Puyang Minghua Chemical Co., Ltd., Model M71S), and 60 g of oil clearing agent (Example 5) were added respectively, and stirred for 10 min under a high-speed stirring condition of 6000 r / min. The obtained test solution was placed in a constant temperature water bath, and the temperature was controlled to 30°C, 60°C and 90°C respectively. The experiment was carried out according to the flushing efficiency evaluation method. The results are shown in Table 3. The density of the biomass synthetic-based drilling fluid used to soak the outer cylinder of the six-speed rotary viscometer is 2.0 g / cm 3 .

[0113] Table 3 Flushing efficiency under different temperature conditions

[0114] Flushing temperature, °C Flushing efficiency, % 30 93.4 60 95.8 90 99.2

[0115] It can be seen from the results in Table 3 that the flushing efficiency of the biomass synthetic-based drilling fluid oil cleaning agent prepared in Example 5 of the present invention increases with increasing temperature, and has a good flushing effect.

[0116] The temperature resistance of the biomass synthetic-based drilling fluid oil clearing agent prepared in Example 5 was evaluated: 400 mL of clean water was taken, 8 g of suspending agent (Puyang Minghua Chemical Co., Ltd., model M71S) was added, and 60 g of the biomass synthetic-based drilling fluid oil clearing agent prepared in Example 5 was added and stirred for 10 min under a high-speed stirring condition of 6000 r / min. The obtained test solution was rolled and aged for 6 hours at 120°C, 150°C, and 180°C, and then taken out and cooled to room temperature. The experiment was carried out according to the flushing efficiency evaluation method. The results are shown in Table 4. The density of the biomass synthetic-based drilling fluid used to soak the outer cylinder of the six-speed rotary viscometer is 2.0 g / cm 3 .

[0117] Table 4 Flushing efficiency after aging

[0118]

[0119]

[0120] From the results in Table 4, it can be seen that the oil cleaning agent for biomass synthetic-based drilling fluid prepared in Example 5 of the present invention has a flushing efficiency of more than 90% after high-temperature aging, which can meet the needs of cementing after using biomass synthetic-based drilling fluid in deep well drilling.

[0121] The salt resistance of the oil clearing agent prepared in Example 5 was evaluated: 400 mL of clean water was taken, and 20 g, 40 g, 60 g, 100 g, 120 g, 144 g of NaCl or 2 g, 4 g, 8 g of CaCl2 were added respectively, and 8 g of suspending agent (Puyang Minghua Chemical Co., Ltd., model M71S) was added after dissolution, and 60 g of the biomass synthetic-based drilling fluid oil clearing agent prepared in Example 5 was added respectively, and stirred for 10 min under high-speed stirring conditions of 6000 r / min. The experiment was conducted according to the flushing efficiency evaluation method, and the results are shown in Table 5. The density of the biomass synthetic-based drilling fluid used for soaking the outer cylinder of the six-speed rotary viscometer is 2.0 g / cm 3 .

[0122] Table 5 Salt tolerance evaluation results

[0123] Salt dosage Flushing efficiency, % 20gNaCl 97.6 40gNaCl 96.2 60gNaCl 94.6 100gNaCl 93.8 144gNaCl 92.5 <![CDATA[2gCaCl2]]> 93.8 <![CDATA[4gCaCl2]]> 93.4 <![CDATA[8gCaCl2]]> 92.4

[0124] It can be seen from the results in Table 5 that the biomass synthetic-based drilling fluid oil clearing agent prepared in Example 5 of the present invention uses different concentrations of NaCl and CaCl2 brines to prepare the flushing fluid, and the flushing efficiency exceeds 90%, which has a good flushing effect and can meet the requirements of the on-site shale formation for the inhibitory property of the flushing fluid.

[0125] The biological toxicity evaluation experiment of the biomass synthetic drilling fluid oil cleaning agent provided by the present invention is based on the national standard GB / T 15441-1995 "Determination of acute toxicity of water quality - Luminescent bacteria method", and the toxicity of Examples 1 to 7 is determined; BOD5 / COD Cr The biodegradability of Example 1 and Example 5 was determined by the DXY-2 type biological acute toxicity tester, referring to the mysid shrimp biological toxicity classification standard confirmed by the U.S. Environmental Protection Agency, and the experimental results are shown in Table 6. As can be seen from Table 6, the oil clearing agent provided by the present invention has no biological toxicity, strong biodegradability, and is beneficial to environmental protection.

[0126] Table 6 Toxicity test of oil clearing agent

[0127] Example <![CDATA[EC 50 ,mg / L]]> <![CDATA[BOD5 / COD Cr ]]> 1 <![CDATA[4.2×10 4 ]]> 0.53 2 <![CDATA[3.9×10 4 ]]> -- 3 <![CDATA[3.7×10 4 ]]> -- 4 <![CDATA[3.65×10 4 ]]> -- 5 <![CDATA[3.72×10 4 ]]> 0.50 6 <![CDATA[3.64×10 4 ]]> -- 7 <![CDATA[3.5×10 4 ]]> --

[0128] Comparative Example 1

[0129] According to the preparation method provided in Example 5, a biomass synthetic-based oil clearing agent for drilling fluid is obtained; the difference is that the penetrant used in Comparative Example 1 is an alkali-resistant penetrant OEP-70 (provided by Nantong Yixun Chemical Technology Co., Ltd.).

[0130] Comparative Example 2

[0131] According to the preparation method provided in Example 5, a biomass synthetic-based oil clearing agent for drilling fluid is obtained; the difference is that the complexing agent used in Comparative Example 2 is tartaric acid (provided by Suzhou Changhong Chemical Co., Ltd.).

[0132] Comparative Example 3

[0133] According to the preparation method provided in Example 5, a biomass synthetic-based oil clearing agent for drilling fluid is obtained; the difference is that: in Comparative Example 3, no dissolution promoter is added.

[0134] Comparative Example 4

[0135] According to the preparation method provided in Example 5, a biomass synthetic-based oil clearing agent for drilling fluid is obtained; the difference is that the emulsifier in Comparative Example 4 is replaced by sodium dodecyl sulfate K12 powder (provided by Linyi Lusen Chemical Co., Ltd.).

[0136] Take 400mL of clean water, add 8g of suspending agent (Puyang Minghua Chemical Co., Ltd., model M71S), and add 60g of the biomass synthetic drilling fluid oil clearing agent prepared in Comparative Examples 1 to 4 or Example 5, respectively, and stir for 10 minutes under 6000r / min high-speed stirring conditions. The obtained test solution is placed in a constant temperature water bath and the temperature is controlled to 30°C. The experiment was carried out according to the flushing efficiency evaluation method. The results are shown in Table 7. The density of the biomass synthetic drilling fluid used to soak the outer cylinder of the six-speed rotary viscometer is 2.0g / cm 3 .

[0137] Table 7 Flushing efficiency of comparative examples 1 to 4 and embodiment 5

[0138] Flushing efficiency, % Comparative Example 1 35.4 Comparative Example 2 22.3 Comparative Example 3 24.8 Comparative Example 4 43.1 Example 5 94.4

[0139] As can be seen from Table 7, by comparing the data of Example 5 and Comparative Examples 1-4, it can be seen that the specific penetrant, complexing agent, solubilizer and emulsifier used in the present invention have a good synergistic effect, which can make the oil clearing agent provided by the present invention have better performance.

[0140] 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 biomass synthetic-based oil cleaning agent for drilling fluid, characterized in that: include: 2 to 15 parts by weight of penetrant; 5 to 30 parts by weight of complexing agent; 1 to 10 parts by weight of a dissolving agent; 8 to 30 parts by weight of emulsifier; Water 100 parts by weight; The penetrant is selected from sulfosuccinate salts and / or polyoxyethylene ether compounds; The complexing agent is selected from organic phosphonates and / or hydroxycarboxylates; The solubilizing agent is selected from dearomatized solvent oil; The emulsifier is selected from betaine zwitterionic surfactants.

2. The biomass synthetic-based oil cleaning agent for drilling fluid according to claim 1, characterized in that: The penetrant is selected from one or more of di-sec-octyl sulfosuccinate sodium salt and / or isomeric tridecanol polyoxyethylene ether.

3. The biomass synthetic-based oil cleaning agent for drilling fluid according to claim 1, characterized in that: The complexing agent is selected from one or more of ethylenediaminetetramethylene phosphate, diethylenetriaminepenta(methylene phosphonate), citric acid, sodium gluconate and sodium alginate.

4. The biomass synthetic-based oil cleaning agent for drilling fluid according to claim 1, characterized in that: The dissolution promoter is selected from one or more of D60, D80 and D100.

5. The biomass synthetic-based oil cleaning agent for drilling fluid according to claim 1, characterized in that: The emulsifier is selected from one or more of cocamidopropyl hydroxysulfonyl betaine, lauramidopropyl betaine and lauramidopropyl hydroxysulfonyl betaine.

6. A method for preparing the biomass synthetic-based oil clearing agent for drilling fluid according to claim 1, characterized in that: The following steps are involved: S) mixing the penetrant, the complexing agent, the solubilizing agent, the emulsifier and water, and reacting them to obtain the oil clearing agent for the biomass synthetic-based drilling fluid.

7. The preparation method according to claim 6, characterized in that: The step S) is specifically: The penetrant is mixed with water and stirred for the first time, then a complexing agent is added and stirred for the second time, a dissolving agent is added and stirred for the third time, and an emulsifier is added and stirred for the fourth time. After the reaction, an oil clearing agent for biomass synthetic-based drilling fluid is obtained.

8. The preparation method according to claim 7, characterized in that: The rotation speeds of the first stirring, the second stirring, the third stirring and the fourth stirring are each independently 300 to 1000 r / min; the time of the first stirring, the second stirring, the third stirring and the fourth stirring is each independently 5 to 20 min; the temperature of the reaction is 30° C. to 50° C.; and the reaction time is 0.5 to 2 h.

9. A method for using the biomass synthetic-based oil cleaning agent for drilling fluid according to claim 1, characterized in that: include: The biomass synthetic-based drilling fluid oil cleaning agent is mixed with the cementing cleaning fluid.

10. The method of use according to claim 9, characterized in that: The mass of the biomass synthetic-based oil cleaning agent for drilling fluid is 10% to 25% of the mass of the cementing cleaning fluid.

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