Heat-resistant water-based drilling fluid additive as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of drilling fluid additives for petroleum drilling, and discloses a heat-resistant water-based drilling fluid additive as well as a preparation method and application thereof. The water-resistant water-based drilling fluid additive is a high-molecular compound which is formed by taking water as a solvent, dissolving animal bone glue to form a glue solution, and performing etherification reaction on the glue solution and bromoethane under the action of a chain transfer agent and a base catalyst. The preparation method comprises the following steps: adding animal bone glue into water, dissolving to obtain a glue solution, sequentially adding sodium hydroxide, sodium carbonate and bromoethane to form a reaction system solution, then adding a chain transfer agent, and heating and refluxing to react to obtain the water-resistant water-based drilling fluid additive. According to the prepared bromoethane modified bone glue, the chain transfer agent is added in the modification process, the technical defect that the molecular weight of the bone glue cannot be manually controlled is overcome, the inhibition effect is obvious, meanwhile, the rheological property of drilling fluid is not affected, and the problems of borehole wall instability and the like caused by shale hydration expansion in the drilling process can be effectively solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of drilling fluid additives for oil drilling, and particularly relates to a bromoethane-modified bone glue BG as an anti-warm water-based drilling fluid additive, its preparation method and application. Background Art

[0002] Deep oil and gas resources in China are widely distributed and have large reserves. They will become the main backup energy to alleviate the contradiction between energy supply and demand in China and are a major guarantee for national energy security. Drilling fluid is the "blood" of the drilling project and is a key technology to prevent serious accidents such as "collapse, stuck pipe, lost circulation, blowout" during deep well drilling. In deep well drilling, the polymer additives in the drilling fluid will decompose at high temperatures, resulting in the deterioration of the drilling fluid performance. The technology of high-temperature resistant drilling fluid faces unprecedented major challenges and is a frontier topic in the drilling field at home and abroad. At present, the high-temperature resistant drilling fluid for deep wells is still mainly based on the polysulfonate drilling fluid system developed in the 1970s, which is difficult to degrade and has poor environmental protection performance. With the increasing strict requirements of the country for environmental protection, it is urgent to develop high-temperature resistant and environmentally friendly drilling fluid treatment agents.

[0003] During the process of developing deep well oil and gas resources, wellbore instability is a common drilling accident problem in deep well drilling operations, which has seriously affected the exploration process of oilfield resources. Adding shale inhibitors to the drilling fluid can, to a certain extent, slow down the hydration dispersion of shale and maintain the stability of the wellbore. The commonly used shale inhibitor SIAT in oilfields can reduce the linear expansion rate of shale to 45.16% when the dosage is 2%, but its high-temperature resistance limit is 120°C and its environmental protection performance is poor; normal pressure polyetheramine D-230 can reduce the linear expansion rate of shale to 50.1% when the dosage is 1%, but it also has disadvantages such as poor high-temperature resistance and weak environmental acceptability. Based on this, it is of great significance to develop a high-temperature resistant drilling fluid additive and an environmentally friendly water-based drilling fluid system. Summary of the Invention

[0004] The object of the present invention is to provide an anti-temperature water-based drilling fluid additive, its preparation method and application in view of the disadvantages that the inhibition rate performance of common shale inhibitors in oil fields remains to be improved, the anti-temperature property is poor and the environmental acceptability is weak during the development of deep well oil and gas resources. Through the modification with ethyl bromide, it has the advantages of strong toughness, large elasticity, low cost, environmental protection and convenient use. The bone glue that is not resistant to water invasion is introduced into the drilling fluid industry in order to develop an anti-temperature water-based drilling fluid additive. The bone glue modified with ethyl bromide prepared in the present invention innovatively adds a chain transfer agent during the modification process, precisely controls its molecular weight, and obtains a modified bone glue with a target molecular weight, solving the technical defect that the molecular weight of bone glue cannot be artificially controlled. Thanks to the control of the molecular weight, while its inhibitory effect is obvious, it has no effect on the rheology of the drilling fluid, and can effectively solve problems such as wellbore instability caused by the hydration swelling of mud and shale during the drilling process. The preparation steps are simple, the reaction conditions are mild, the cost is low, and other component raw materials are easily available, and it can be used for industrial production.

[0005] In order to achieve the above object, the technical solution adopted in this application is as follows:

[0006] One of the objects of the present invention is to provide an anti-temperature water-based drilling fluid additive, which is a high molecular compound formed by dissolving animal bone glue in water as a solvent to form a glue solution, and through an etherification reaction of the glue solution and ethyl bromide under the action of a chain transfer agent and an alkali catalyst.

[0007] Preferably, the animal bone glue is bovine bone glue, and the bovine bone glue includes Mongolian cattle, Qinchuan cattle, Nanyang cattle and Luxi cattle.

[0008] Another object of the present invention is to provide a preparation method of the above anti-temperature water-based drilling fluid additive, including the following steps:

[0009] Add water to the animal bone glue and dissolve it to obtain a glue solution, then successively add sodium hydroxide, sodium carbonate and ethyl bromide to form a reaction system solution, and then add a chain transfer agent to the system solution for heating and reflux reaction. After the reaction is completed, it can be obtained by purification and drying to obtain the anti-temperature water-based drilling fluid additive solution.

[0010] Preferably, the mass ratio of the animal bone glue to water is 1:1 to 1:1.5.

[0011] Preferably, the dissolution temperature is 60 to 70 °C and the time is 1 to 3 h.

[0012] Preferably, the mass ratio of the animal bone glue to sodium hydroxide is 1:0.5 to 1; the mass ratio of the animal bone glue to sodium carbonate is 1:0.5 to 1.

[0013] Preferably, the mass ratio of the animal bone glue to ethyl bromide is 1:1 to 4.

[0014] Preferably, the chain transfer agent is 0.05-0.15% of the mass of the glue solution, and the chain transfer agent is dodecyl mercaptan; the temperature of the heating reflux reaction is 50-70 °C, and the time is 4-6 h; the purification method is washing 2-4 times with ethyl acetate, and the drying is vacuum drying. The temperature of the vacuum drying is 35 °C, and the time is 4 h.

[0015] Preferably, the molecular weight of the modified bone glue is between 8237 and 8526 g / mol.

[0016] The third object of the present invention is to provide the application of the above anti-warm water-based drilling fluid additive as a shale inhibitor in drilling fluid. When in use, based on the mass of water in the configured drilling fluid system, the addition amount of the anti-warm water-based drilling fluid additive is 1-5%.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] (1) The present invention modifies bone glue with bromoethane, innovatively adds a chain transfer agent, precisely controls its molecular weight between 8237-8526 g / mol, and obtains a modified bone glue with a target molecular weight, solving the technical defect that the molecular weight of bone glue cannot be artificially controlled; solving the water invasion resistance of bone glue, and researching an environmentally friendly, anti-warm water-based drilling fluid additive, which has obvious inhibitory effect and has no influence on the rheology of the drilling fluid.

[0019] (2) The well fluid additive prepared by the present invention is that the alkyl group of bromoethane and the hydroxyl functional group on the bone glue undergo an etherification reaction to form a haloalkane, and the function of the two is to undergo an etherification reaction. The mechanism of generating inhibition is that the unmodified hydroxyl part on the modified bone glue forms a hydrogen bond with the clay and repels the water between the clay crystal layers, thereby playing an inhibitory role, solving the disadvantages such as the performance of the inhibition rate of the commonly used shale inhibitors in existing oil fields remaining to be improved, poor anti-temperature performance, and weak environmental acceptability.

[0020] (3) The anti-warm water-based drilling fluid additive of the present invention has good thermal stability and good inhibition in fresh water base mud; this product is easily soluble in water and can be directly used in water-based drilling fluid; the preparation steps are simple, the reaction conditions are mild, the cost is low, and other component raw materials are easily available, and it can be used for industrial production. Description of the Drawings

[0021] Figure 1 It is the infrared light diagram of the anti-warm water-based drilling fluid additive prepared in Example 5 of the present invention;

[0022] Figure 2 It is the XRD diagram of the anti-warm water-based drilling fluid additive prepared in Example 5 of the present invention;

[0023] Figure 3Linear expansion rate of the base slurry of the anti-warm water-based drilling fluid additive prepared in Example 5 with different concentrations of the present invention;

[0024] Figure 4 Linear expansion rate of the base slurry of the anti-warm water-based drilling fluid additive prepared in Example 5 of the present invention at different temperatures;

[0025] Figure 5 Linear expansion rate of the base slurries of the anti-warm water-based drilling fluid additives prepared in Example 5 and Comparative Example 1 of the present invention at 120 °C;

[0026] Figure 6 Linear expansion rate of the base slurries of the anti-warm water-based drilling fluid additives prepared in Example 5 and Comparative Example 2 of the present invention at 120 °C;

[0027] Figure 7 Linear expansion rate of the base slurry of the anti-warm water-based drilling fluid additive prepared in Example 1 with different concentrations of the present invention;

[0028] Figure 8 Linear expansion rate of the base slurry of the anti-warm water-based drilling fluid additive prepared in Example 2 with different concentrations of the present invention;

[0029] Figure 9 Linear expansion rate of the base slurry of the anti-warm water-based drilling fluid additive prepared in Example 3 with different concentrations of the present invention;

[0030] Figure 10 Linear expansion rate of the base slurry of the anti-warm water-based drilling fluid additive prepared in Example 4 with different concentrations of the present invention;

[0031] Figure 11 Linear expansion rate of the base slurry of the anti-warm water-based drilling fluid additive prepared in Example 6 with different concentrations of the present invention. Detailed implementation manners

[0032] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the data in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

[0033] It should be noted that the professional terms used in the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the protection scope of the present invention. Unless otherwise specifically stated, various raw materials, reagents, instruments, and equipment used in the following embodiments of the present invention can be obtained through market purchase or prepared by existing methods.

[0034] The invention provides a temperature-resistant water-based drilling fluid additive. The temperature-resistant water-based drilling fluid additive is a polymer compound formed by etherification reaction of the glue and ethyl bromide under the action of a chain transfer agent and an alkali catalyst by dissolving animal bone glue to form a glue solution with water as a solvent.

[0035] In some preferred embodiments, the animal bone glue is bovine bone glue, and the bovine bone glue includes Mongolian cattle, Qinchuan cattle, Nanyang cattle and Luxi cattle.

[0036] The animal bone glue used in the present invention is a degradable natural polymer compound with the disadvantages of strong toughness, high elasticity, low cost, environmental protection and easy use. However, it is not resistant to water invasion, and dissolving in water will cause its adhesion to decrease. It is currently used in drilling fluids, but its modified hydrophobicity and temperature resistance can be greatly improved, and it is expected to be used as a temperature-resistant and environmentally friendly shale inhibitor. The present invention introduces bone glue derived from cattle bones, which has excellent temperature resistance but has never been used in oilfield chemistry, into the drilling fluid industry, in order to develop an environmentally friendly and temperature-resistant water-based drilling fluid additive. After experimental testing, the modified product was aged at 130°C, and its shale inhibition effect was good.

[0037] The preparation method of the above-mentioned temperature-resistant water-based drilling fluid additive comprises the following steps:

[0038] Water is added to the animal glue to fully dissolve it to obtain glue solution, and then sodium hydroxide, sodium carbonate and ethyl bromide are added in sequence to form a reaction system solution. Then a chain transfer agent is added to the system solution to carry out heating reflux reaction. After the reaction is completed, the temperature-resistant water-based drilling fluid additive can be obtained after purification and drying.

[0039] The reaction formula of ethyl bromide-modified bone glue is as follows:

[0040]

[0041] The present invention is that the alkyl group of ethyl bromide and the hydroxyl functional group on the gelatin undergo etherification reaction to generate alkyl halide, and the two functions to undergo etherification reaction. The mechanism of producing inhibition is that the unmodified hydroxyl part on the modified gelatin undergoes hydrogen bond adsorption with clay and repels water between clay crystal layers, thereby playing an inhibitory role, solving the shortcomings of the existing shale inhibitors commonly used in oil fields, such as the inhibition rate performance needs to be improved, poor temperature resistance and weak environmental acceptability.

[0042] In some preferred embodiments, the mass ratio of the animal gelatin to water is 1:1 to 1:1.5.

[0043] In some preferred embodiments, the dissolution temperature is 60-70° C. and the dissolution time is 1-3 hours.

[0044] In some preferred embodiments, the mass-to-volume ratio of the animal bone glue to the solvent is 1 g: 20 - 30 mL; the mass ratio of the animal bone glue to sodium hydroxide is 1: 0.5 - 1; the mass ratio of the animal bone glue to sodium carbonate is 1: 0.5 - 1.

[0045] In some preferred embodiments, the mass ratio of the animal bone glue to bromoethane is 1: 1 - 4.

[0046] In some preferred embodiments, the chain transfer agent is 0.05 - 0.15% of the mass of the glue solution, the chain transfer agent is dodecyl mercaptan, the temperature of the heating reflux reaction is 50 - 70 °C, and the time is 4 - 6 h; the purification method is to wash with ethyl acetate 2 - 4 times, and then perform vacuum drying, the drying temperature is 35 °C, and the time is 4 h.

[0047] In some preferred embodiments, the molecular weight of the modified bone glue is between 8237 - 8526 g / moL.

[0048] Using the above water-based drilling fluid additive as a shale inhibitor in the drilling fluid, the drilling fluid includes the following components: 350 mL of clear water, 14 g of calcium clay, and 0.7 g of anhydrous sodium carbonate. When in use, based on the mass of water in the configured drilling fluid system, the addition amount of the water-based drilling fluid additive is 1 - 5%.

[0049] The following is further illustrated with specific examples.

[0050] Example 1

[0051] A preparation method of a water-based drilling fluid additive includes the following steps:

[0052] S1. Add Mongolian cattle bone glue and water to a three-necked flask in a mass ratio of 1: 1, dissolve the bone glue in water in a 60 °C water bath environment for 1 h to obtain a viscoelastic glue solution;

[0053] S2. Add 20 mL of absolute ethanol to the glue solution, then sequentially add 0.5 g of sodium hydroxide and 0.1 g of sodium carbonate, then add 1 g of bromoethane while stirring under this reaction condition, and then add 0.05% (by weight of the glue solution) of dodecyl mercaptan to control the molecular weight of the reaction system. Then seal the three-necked flask, raise the reaction temperature to 50 °C for a condensation reflux reaction for 4 h. After the reaction is completed, take out the viscous product in the flask to obtain bromoethane-modified bone glue BG. After purification by washing with ethyl acetate 3 times and vacuum drying at 35 °C for 4 h, a dark orange viscous liquid with a molecular weight of 8240 g / moL is obtained, which is the anti-temperature water-based drilling fluid additive.

[0054] Example 2

[0055] A preparation method of a water-based drilling fluid additive, comprising the following steps:

[0056] S1. Add Mongolian cattle bone glue and water into a three-necked flask at a mass ratio of 1:1, dissolve the bone glue in water in a 70°C water bath environment for 1 h to obtain a viscoelastic glue solution;

[0057] S2. Add 30 mL of absolute ethanol to the glue solution, then sequentially add 0.5 g of sodium hydroxide and 0.1 g of sodium carbonate, then add 2 g of bromoethane while stirring under this reaction condition, and then add 0.05% (by mass of the glue solution) of dodecyl mercaptan to control the molecular weight of the reaction system. Then seal the three-necked flask, raise the reaction temperature to 60°C and carry out a condensation reflux reaction for 5 h. After the reaction is completed, take out the viscous product in the flask to obtain bromoethane-modified bone glue BG. After washing with ethyl acetate 3 times for purification and vacuum drying at 35°C for 4 h, a dark orange viscous liquid with a molecular weight of 8279 g / moL is obtained, which is the anti-temperature water-based drilling fluid additive.

[0058] Example 3

[0059] A preparation method of a water-based drilling fluid additive, comprising the following steps:

[0060] S1. Add Mongolian cattle bone glue and water into a three-necked flask at a mass ratio of 1:1.1, dissolve the bone glue in water in a 70°C water bath environment for 2 h to obtain a viscoelastic glue solution;

[0061] S2. Add 30 mL of absolute ethanol to the glue solution, then sequentially add 1 g of sodium hydroxide and 0.5 g of sodium carbonate, then add 3 g of bromoethane while stirring under this reaction condition, and then add 0.1% (by mass of the glue solution) of dodecyl mercaptan to control the molecular weight of the reaction system. Then seal the three-necked flask, raise the reaction temperature to 60°C and carry out a condensation reflux reaction for 5 h. After the reaction is completed, take out the viscous product in the flask to obtain bromoethane-modified bone glue BG. After washing with ethyl acetate 3 times for purification and vacuum drying at 35°C for 4 h, a dark orange viscous liquid with a molecular weight of 8367 g / moL is obtained, which is the anti-temperature water-based drilling fluid additive.

[0062] Example 4

[0063] A preparation method of a water-based drilling fluid additive, comprising the following steps:

[0064] S1. Add Mongolian cattle bone glue and water into a three-necked flask at a mass ratio of 1:1.3, dissolve the bone glue in water in a 70°C water bath environment for 3 h to obtain a viscoelastic glue solution;

[0065] S2. Add 20 mL of absolute ethanol to the glue solution, then sequentially add 1 g of sodium hydroxide and 0.5 g of sodium carbonate. Then, while stirring under this reaction condition, add 4 g of bromoethane. After that, add 0.12% (by weight of the glue solution) of dodecyl mercaptan to control the molecular weight of the reaction system. Then seal the three-necked flask, raise the reaction temperature to 60 °C and carry out a reflux condensation reaction for 5.5 h. After the reaction is completed, take out the viscous product in the flask to obtain bromoethane-modified bone glue BG. After washing with ethyl acetate three times for purification and vacuum drying at 35 °C for 4 h, a dark orange viscous liquid with a molecular weight of 8437 g / mol is obtained, which is the warm-resistant water-based drilling fluid additive.

[0066] Example 5

[0067] A preparation method of a water-based drilling fluid additive, comprising the following steps:

[0068] S1. Add Mongolian cattle bone glue and water to a three-necked flask in a mass ratio of 1:1. Dissolve the bone glue in water in a 60 °C water bath environment for 2 h to obtain a viscoelastic glue solution;

[0069] S2. Add 20 mL of absolute ethanol to the glue solution, then sequentially add 1 g of sodium hydroxide and 0.5 g of sodium carbonate. Then, while stirring under this reaction condition, add 4 g of bromoethane. After that, add 0.1% (by weight of the glue solution) of dodecyl mercaptan to control the molecular weight of the reaction system. Then seal the three-necked flask, raise the reaction temperature to 60 °C and carry out a reflux condensation reaction for 5.5 h. After the reaction is completed, take out the viscous product in the flask to obtain bromoethane-modified bone glue BG. After washing with ethyl acetate three times for purification and vacuum drying at 35 °C for 4 h, a dark orange viscous liquid with a molecular weight of 8486 g / mol is obtained, which is the warm-resistant water-based drilling fluid additive.

[0070] Example 6

[0071] A preparation method of a water-based drilling fluid additive, comprising the following steps:

[0072] S1. Add Mongolian cattle bone glue and water to a three-necked flask in a mass ratio of 1:1.5. Dissolve the bone glue in water in a 60 °C water bath environment for 3 h to obtain a viscoelastic glue solution;

[0073] S2. Add 20 mL of absolute ethanol to the glue solution, then sequentially add 1 g of sodium hydroxide and 0.5 g of sodium carbonate. While stirring under this reaction condition, add 4 g of bromoethane, and then add 0.15% (by weight of the glue solution) of dodecyl mercaptan to control the molecular weight of the reaction system. Then seal the three-necked flask, heat the reaction to 70 °C and carry out a reflux condensation reaction for 6 h. After the reaction is completed, take out the viscous product in the flask to obtain bromoethane-modified bone glue BG. After washing 3 times with ethyl acetate for purification and vacuum drying at 35 °C for 4 h, a dark orange viscous liquid with a molecular weight of 8517 g / moL is obtained, which is the anti-warm water-based drilling fluid additive.

[0074] Comparative Example 1

[0075] A preparation method of a water-based drilling fluid additive includes the following steps:

[0076] Add Mongolian cattle bone glue and water to a three-necked flask in a mass ratio of 1:1. Dissolve the bone glue in water in a 60 °C water bath environment for 2 h to obtain a viscoelastic glue solution, which is the water-based drilling fluid additive.

[0077] Comparative Example 2

[0078] A preparation method of a water-based drilling fluid additive includes the following steps:

[0079] S1. Add Mongolian cattle bone glue and water to a three-necked flask in a mass ratio of 1:1. Dissolve the bone glue in water in a 60 °C water bath environment for 2 h to obtain a viscoelastic glue solution;

[0080] S2. Add 20 mL of absolute ethanol to the glue solution, then sequentially add 1 g of sodium hydroxide and 0.5 g of sodium carbonate. While stirring under this reaction condition, add 4 g of bromoethane, then seal the three-necked flask, heat the reaction to 60 °C and carry out a reflux condensation reaction for 5.5 h. After the reaction is completed, take out the viscous product in the flask to obtain bromoethane-modified bone glue BG. After washing 3 times with ethyl acetate for purification and vacuum drying at 35 °C for 4 h, a dark orange viscous liquid with a molecular weight of 134372 g / moL is obtained. Since it cannot enter the inside of the clay crystal layer, its inhibition performance is poor.

[0081] To evaluate the inhibition effect of this product, the water-based drilling fluid additives prepared in Examples 1-6 and Comparative Examples 1-2 were analyzed as follows.

[0082] 1. Infrared analysis

[0083] Take the water-based drilling fluid additive prepared in Example 5 and the glue solution of Comparative Example 1 and place them on the sample holder for testing with a Bruker infrared spectrometer. Figure 1 It is the infrared light diagram of bromoethane-modified bone glue BG prepared in Example 5 of the present invention. Figure 1In this, a is the glue solution of Comparative Example 1, and b is the bromoethane-modified bone glue BG prepared in Example 5. As Figure 1 shown, a shoulder peak appears near 3400 cm -1 . In the third peak region, a secondary amine bending vibration appears near 1550 cm -1 , indicating the presence of an N-H bond; in the first peak region, a sharp peak appears near 2960 cm -1 , indicating the presence of C-CH3; in the third peak region, a C-N stretching vibration peak appears near 1640 cm -1 ; these indicate that the amino group on the animal bone glue molecule has fully undergone a halogenation reaction with bromoethane to form a new product. A stretching vibration peak appears near 1030 cm -1 , indicating the presence of a C-O bond in the modified bone glue. A weak absorption band appears near 880 cm -1 in the fourth peak region, indicating the occurrence of (CH2)n plane rocking vibration, indicating that the animal bone glue molecule did not decompose into small molecules during the reaction with bromoethane, and the reaction achieved the purpose of combining bromoethane molecules with animal bone glue molecules. It shows that the environmentally friendly and modified bone glue has been successfully synthesized.

[0084] 2. XRD analysis

[0085] Take two groups of 350 mL of base slurry in 500 mL beakers respectively (the base slurry is composed of the following components: 350 mL of clear water, 14 g of calcium soil, and 0.7 g of anhydrous sodium carbonate). One group is used as a blank control, and the other group is added with 4% of the water-based drilling fluid additive prepared in Example 5. Stir at high speed for 30 min to fully mix the modified glue solution and the drilling fluid base slurry evenly;

[0086] Pour these two groups of samples into centrifuge cups. After centrifuging at 4000 revolutions for 20 min in a centrifuge, pour out the supernatant. Put the remaining mud into a clean watch glass, place it in an oven at 120 °C and dry for 24 h until it is dry and lumpy without moisture. Take out the sample, pour it into a mortar, grind it, and sieve it repeatedly with a sieve to obtain the required sample. Perform XRD testing on the sample, with a scanning range of 2θ = 5 - 80°, and a scanning speed of 10° / min.

[0087] Figure 2 This is the XRD pattern of the water-based drilling fluid additive prepared in Example 5 of the present invention. As Figure 2 shown, the results show that although corresponding peaks appear in the XRD spectra of the base slurry before and after adding this product, the peaks that appear are smaller or overlap with other peaks. The reason may be that the SiO2 characteristic peak is too strong, etc. Indirectly, the main functional groups of this product are adsorbed in the base slurry, and its adsorption effect is obvious.

[0088] 3. Linear expansion experiment

[0089] The test method for the linear swelling rate of the inhibitory material using bentonite refers to the standard SY / T 6335-1997. Weigh 8 ± 0.01 g of 100-mesh sodium-based bentonite dried at 100 ± 5 °C for 4 h and cooled to room temperature, and place it in a measuring cylinder. After pressing for 5 min at a pressure of 10 MPa on a press, remove the pressure, take out the plug rod, take out the pressed tablet, and then measure the thickness of the core with a vernier caliper. Based on the mass of water in the prepared drilling fluid system, pour 1%, 2%, 3%, 4%, and 5% of the water-based drilling fluid additive prepared in Example 5 into the measuring cylinder, and use a normal-temperature and normal-pressure linear expansion instrument to measure the linear swelling rate, and record the readings at different times. The test results are as Figure 3 shown. The final linear swelling rate of the base slurry is 51.2%, and the linear swelling rate of the base slurry with 4% of the water-based drilling fluid additive prepared in Example 5 added is 38.2%. From the experimental results, it can be seen that after adding 4% of the water-based drilling fluid additive prepared in Example 5 to the base slurry, the linear swelling rate decreased by 13%, indicating that the water-based drilling fluid additive prepared in Example 5 has good inhibition on the base slurry.

[0090] Measure the linear swelling rate of the base slurry with 4% of the water-based drilling fluid additive prepared in Example 5 on a normal-pressure linear expansion instrument at different temperatures of 100 °C, 110 °C, 120 °C, and 130 °C, and record the readings at different times. The test results are as Figure 4 shown. Figure 4 It shows the influence of temperature on the linear swelling rate of this product. As Figure 4 shown, at 100 °C, the linear swelling rate of the base slurry with 4% of this product added is 46.8%; at 110 °C, the linear swelling rate of the base slurry with 4% of this product added is 44.2%; at 120 °C, the linear swelling rate of the base slurry with 4% of the water-based drilling fluid additive prepared in Example 5 added is 38.2%; at 130 °C, the linear swelling rate of the base slurry with 4% of the water-based drilling fluid additive prepared in Example 5 added is 41.9%. The results show that the water-based drilling fluid additive prepared in Example 5 still shows good inhibition at 130 °C.

[0091] Figure 5 This is the linear swelling rate at 120 °C of the base slurries of the water-based drilling fluid additives prepared in Example 5 and Comparative Example 1 of the present invention. As Figure 5 shown, the linear swelling rate of the base slurry with 4% of the unmodified bone glue added is 52%, and the linear swelling rate of the base slurry with 4% of the modified bone glue added is 38.2%.

[0092] Figure 6 This is the linear swelling rate at 120 °C of the base slurries of the water-based drilling fluid additives prepared in Example 5 and Comparative Example 2 of the present invention. As Figure 6 shown, the linear swelling rate of the base slurry before adding the chain transfer agent is 42.08, and the linear swelling rate of the base slurry after adding the chain transfer agent is 38.2%.

[0093] Figure 7 The linear expansion rate of the base slurry of the water-based drilling fluid additive prepared in Example 1 with different concentrations of the present invention. As Figure 7 shown, when the dosage of the water-based drilling fluid additive prepared in Example 1 is 1%, the linear expansion rate of the base slurry is 50.2%; when the dosage is 2%, the linear expansion rate of the base slurry is 49.1%; when the dosage is 3%, the linear expansion rate of the base slurry is 47.9%; when the dosage is 4%, the linear expansion rate of the base slurry is 46.8%; when the dosage is 5%, the linear expansion rate of the base slurry is 46.2%.

[0094] Figure 8 The linear expansion rate of the base slurry of the water-based drilling fluid additive prepared in Example 2 with different concentrations of the present invention. As Figure 8 shown, when the dosage of the water-based drilling fluid additive prepared in Example 2 is 1%, the linear expansion rate of the base slurry is 50.4%; when the dosage is 2%, the linear expansion rate of the base slurry is 49%; when the dosage is 3%, the linear expansion rate of the base slurry is 47%; when the dosage is 4%, the linear expansion rate of the base slurry is 46%; when the dosage is 5%, the linear expansion rate of the base slurry is 45.4%.

[0095] Figure 9 The linear expansion rate of the base slurry of the water-based drilling fluid additive prepared in Example 3 with different concentrations of the present invention. As Figure 9 shown, when the dosage of the water-based drilling fluid additive prepared in Example 3 is 1%, the linear expansion rate of the base slurry is 52.6%; when the dosage is 2%, the linear expansion rate of the base slurry is 50.5%; when the dosage is 3%, the linear expansion rate of the base slurry is 48.7%; when the dosage is 4%, the linear expansion rate of the base slurry is 48%; when the dosage is 5%, the linear expansion rate of the base slurry is 47.1%.

[0096] Figure 10 The linear expansion rate of the base slurry of the water-based drilling fluid additive prepared in Example 4 with different concentrations of the present invention. As Figure 4As shown, when the dosage of the water-based drilling fluid additive prepared in Example 4 is 1%, the linear expansion rate of the base slurry is 49.8%; when the dosage of the water-based drilling fluid additive prepared in Example 4 is 2%, the linear expansion rate of the base slurry is 48%; when the dosage of the water-based drilling fluid additive prepared in Example 4 is 3%, the linear expansion rate of the base slurry is 47.5%; when the dosage of the water-based drilling fluid additive prepared in Example 4 is 4%, the linear expansion rate of the base slurry is 46.1%; when the dosage of the water-based drilling fluid additive prepared in Example 4 is 5%, the linear expansion rate of the base slurry is 45.1%.

[0097] Figure 11 This is the linear expansion rate of the base slurry of the water-based drilling fluid additive prepared in Example 6 of the present invention at different concentrations. As Figure 11 shown, when the dosage of the water-based drilling fluid additive prepared in Example 6 is 1%, the linear expansion rate of the base slurry is 47.8%; when the dosage of the water-based drilling fluid additive prepared in Example 6 is 2%, the linear expansion rate of the base slurry is 45.1%; when the dosage of the water-based drilling fluid additive prepared in Example 6 is 3%, the linear expansion rate of the base slurry is 43.1%; when the dosage of the water-based drilling fluid additive prepared in Example 6 is 4%, the linear expansion rate of the base slurry is 41.9%; when the dosage of the water-based drilling fluid additive prepared in Example 6 is 5%, the linear expansion rate of the base slurry is 40.2%.

[0098] It should be noted that when the present invention involves a numerical range, it should be understood that any value between the two endpoints of each numerical range and the two endpoints can be selected. Since the steps and methods adopted are the same as those in the embodiments, in order to prevent repetition, the present invention describes the preferred embodiments. Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications to these embodiments once they know the basic creative concept. Therefore, the appended claims are intended to be interpreted to include the preferred embodiments and all changes and modifications falling within the scope of the present invention.

[0099] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these changes and modifications.

Claims

1. An anti-warm water-based drilling fluid additive, characterized in that, The anti-warm water-based drilling fluid additive is a polymer compound formed by dissolving animal bone glue in water as a solvent to form a glue solution, and through an etherification reaction between the glue solution and ethyl bromide under the action of a chain transfer agent and an alkali catalyst.

2. The water-based drilling fluid additive resistant to warm water according to claim 1, characterized in that, The animal bone glue is bovine bone glue, and the bovine bone glue includes Mongolian cattle, Qinchuan cattle, Nanyang cattle and Luxi cattle.

3. The preparation method of the warm water-resistant water-based drilling fluid additive according to claim 1 or 2, characterized in that, It includes the following steps: Add water to the animal bone glue and dissolve it to obtain a glue solution, then successively add sodium hydroxide, sodium carbonate, and ethyl bromide to form a reaction system solution, and then add a chain transfer agent to the system solution for heating and reflux reaction. After the reaction is completed, it can be obtained by purification and drying to obtain the anti-warm water-based drilling fluid additive.

4. The preparation method of the warm-water resistant water-based drilling fluid additive according to claim 3, characterized in that, The mass ratio of the animal bone glue to water is 1:1 to 1:1.

5.

5. The preparation method of the warm water resistant water-based drilling fluid additive according to claim 3, characterized in that, The temperature of the dissolution is 60 to 70 °C, and the time is 1 to 3 h.

6. The preparation method of the warm water resistant water-based drilling fluid additive according to claim 3, characterized in that, The mass ratio of the animal bone glue to sodium hydroxide is 1:0.5 to 1; the mass ratio of the animal bone glue to sodium carbonate is 1:0.5 to 1.

7. The preparation method of the warm-resistant water-based drilling fluid additive according to claim 3, wherein, The mass ratio of the animal bone glue to ethyl bromide is 1:1 to 4.

8. The preparation method of the warm water resistant water-based drilling fluid additive according to claim 3, characterized in that, The chain transfer agent is 0.05 to 0.15% of the total mass of the glue solution, and the chain transfer agent is dodecyl mercaptan; the temperature of the heating and reflux reaction is 50 to 70 °C, and the time is 4 to 6 h; the purification method is washing with ethyl acetate 2 to 4 times, and the drying is vacuum drying. The temperature of the vacuum drying is 35 °C, and the time is 4 h.

9. The preparation method of the warm water-resistant water-based drilling fluid additive according to claim 3, wherein The molecular weight of the modified bone glue is 8237 to 8526 g / moL.

10. Use of the warm water-resistant water-based drilling fluid additive according to claim 1 or 2 as a shale inhibitor in a drilling fluid, characterized in that When in use, based on the mass of water in the configured drilling fluid system, the addition amount of the anti-warm water-based drilling fluid additive is 1 to 5%.

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