Shell-containing plugging agent for high-pressure-bearing drilling fluid and preparation method of shell-containing plugging agent

Abstract

The invention relates to the technical field of well drilling, and provides a shell-containing plugging agent for high-pressure-bearing drilling fluid and a preparation method of the shell-containing plugging agent. The shell-containing plugging agent for the drilling fluid is prepared from the following components in parts by weight: 12 to 20 parts of shell, 15 to 25 parts of basalt fiber, 8 to 14 parts of phenolic resin, 10 to 15 parts of organic silicon modified epoxy resin, 1 to 6 parts of surfactant, 3 to 16 parts of carboxymethyl hydroxyethyl cellulose, 0.5 to 1.5 parts of tackifier, 70 to 80 parts of cement and 150 parts of water. According to the technical scheme, the problems of poor pressure bearing capacity and poor plugging effect of the shell-containing plugging agent for the drilling fluid in the prior art are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of drilling, and in particular to a fruit shell-containing plugging agent for high-pressure drilling fluid and a preparation method thereof. Background Art

[0002] Well leakage is a complex situation downhole, a phenomenon in which drilling fluid, cement slurry or other working fluids are lost to the bottom layer during drilling engineering. Minor well leakage has little impact on drilling operations, but severe well leakage will not only affect the orderly progress of drilling operations, but may also cause accidents such as blowouts and well collapses, affecting the safe progress of drilling operations and causing a sharp increase in drilling economic costs. Therefore, in order to plug the leaking layer in time, plugging agents are necessary in drilling operations.

[0003] As drilling becomes increasingly difficult, demands for higher performance from plugging agents are rising. Various plugging agents are emerging, and plugging materials containing nutshells are widely used in drilling operations due to their safety, convenience, and wide applicability. However, current plugging agents containing nutshells have poor pressure-bearing capacity and are unable to effectively seal cracks of varying sizes, thus limiting their effectiveness. Therefore, improving the pressure-bearing capacity of nutshell plugging agents while ensuring they can effectively seal cracks of varying sizes is a pressing technical challenge. Summary of the Invention

[0004] The invention provides a fruit shell-containing plugging agent for high-pressure drilling fluid and a preparation method thereof, which solves the problems of poor pressure bearing capacity and poor plugging effect of the fruit shell-containing plugging agent for drilling fluid in the related art.

[0005] The technical solutions of the present invention are as follows: The present invention provides a fruit shell-containing plugging agent for high-pressure drilling fluid, comprising the following components in parts by weight: 12-20 parts of fruit shells, 15-25 parts of basalt fibers, 8-14 parts of phenolic resin, 10-15 parts of silicone-modified epoxy resin, 1-6 parts of surfactant, 3-16 parts of carboxymethyl hydroxyethyl cellulose, 0.5-1.5 parts of tackifier, 70-80 parts of cement, and 150 parts of water.

[0006] As a further technical solution, the weight ratio of the basalt fiber to the carboxymethyl hydroxyethyl cellulose is 2-4:1.

[0007] When the weight ratio of basalt fiber to carboxymethyl hydroxyethyl cellulose is 2-4:1, the pressure bearing capacity and plugging effect of the fruit shell-containing plugging agent for drilling fluid can be further improved.

[0008] As a further technical solution, the basalt fiber is a modified basalt fiber, and the raw materials of the modified basalt fiber include basalt fiber, rectorite and polyacrylate.

[0009] Basalt fiber is modified with rectorite and polyacrylate. The modification not only improves the dispersibility of basalt fiber but also promotes the combination of basalt fiber and carboxymethyl hydroxyethyl cellulose, thereby further strengthening the density of the structure of the fruit shell plugging agent for drilling fluid, thereby further improving the pressure bearing capacity and plugging effect of the fruit shell plugging agent for drilling fluid.

[0010] As a further technical solution, the weight ratio of the basalt fiber, rectorite and polyacrylate is 8-18:1.5:0.5.

[0011] When the weight ratio of basalt fiber, rectorite and polyacrylate is 8-18:1.5:0.5, the pressure bearing capacity and plugging effect of the fruit shell-containing plugging agent for drilling fluid can be further improved.

[0012] As a further technical solution, the preparation method of the modified basalt fiber comprises the following steps: A1. blending the basalt fiber and the rectorite, and grinding to obtain a mixture; A2. Dissolving the polyacrylate in ethyl acetate to obtain a polyacrylate solution, adding the mixture to the polyacrylate solution, dispersing the mixture evenly, concentrating, and drying to obtain modified basalt fiber.

[0013] As a further technical solution, the diameter of the basalt fiber is 16-30 μm and the length is 1-3 mm; the particle size of the rectorite is 100-150 nm.

[0014] As a further technical solution, the mass fraction of the polyacrylate solution is 3% to 6%.

[0015] As a further technical solution, the fruit shell is one or more of peanut shell, walnut shell, and cottonseed shell.

[0016] As a further technical solution, the surfactant is one or more of polyoxyethylene fatty alcohol ether, sucrose fatty acid ester, and octylphenol polyoxyethylene ether.

[0017] As a further technical solution, the tackifier is one or both of polyvinyl alcohol and xanthan gum.

[0018] The present invention also provides a method for preparing a fruit shell-containing plugging agent for high-pressure drilling fluid, comprising the following steps: mixing the fruit shell and cement, ball milling the mixture, adding the remaining components, blending the mixture, and stirring to obtain the fruit shell-containing plugging agent for drilling fluid.

[0019] As a further technical solution, during the stirring, the stirring speed is 1000-1200 r / min and the stirring time is 25-45 min.

[0020] The working principle and beneficial effects of the present invention are: In the present invention, the fruit shell-containing plugging agent for drilling fluid is a high-pressure-bearing fruit shell-containing plugging agent for drilling fluid. The fruit shell-containing plugging agent for drilling fluid is made of fruit shells, basalt fibers, phenolic resins, organically modified epoxy resins, carboxymethyl hydroxyethyl cellulose, cement, water and other raw materials. The effective combination of the various components makes the fruit shell-containing plugging agent for drilling fluid have excellent pressure-bearing capacity, can also adapt to cracks of different sizes, and have excellent plugging effect. Among them, the raw materials of the fruit shell-containing plugging agent for drilling fluid include basalt fibers and carboxymethyl hydroxyethyl cellulose. By coordinating the two, the fruit shell-containing plugging agent for drilling fluid can have rheological properties and a tighter structure, thereby significantly improving its pressure-bearing capacity and plugging effect. DETAILED DESCRIPTION

[0021] 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 embodiments described 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 any creative efforts are within the scope of protection of the present invention.

[0022] In the following examples and comparative examples, the fruit shell is peanut shell with a particle size of 80 mesh; the diameter of the basalt fiber is 17 μm and the length is 3 mm; the model of the phenolic resin is SP-1068; the model of the silicone-modified epoxy resin is HYSZ17; the model of the carboxymethyl hydroxyethyl cellulose is Darl-1 with a viscosity of 4000; the tackifier is polyvinyl alcohol with a model of PVA2488; the surfactant is polyoxyethylene fatty alcohol ether with a model of MOA-3B; and the cement is aluminate cement with a model of CA50-G6.

[0023] Example 1 A fruit shell-containing plugging agent for high-pressure drilling fluid comprises the following components in parts by weight: 12 parts of fruit shells, 15 parts of basalt fiber, 8 parts of phenolic resin, 10 parts of silicone-modified epoxy resin, 1 part of polyoxyethylene fatty alcohol ether, 3 parts of carboxymethyl hydroxyethyl cellulose, 0.5 parts of polyvinyl alcohol, 70 parts of cement, and 150 parts of water; The preparation method of the fruit shell-containing plugging agent for drilling fluid comprises the following steps: The fruit shells and cement are mixed and ball-milled, and then the remaining components are added and blended, and stirred at 1000 r / min for 45 minutes to obtain a fruit shell-containing plugging agent for drilling fluid.

[0024] Example 2 A fruit shell-containing plugging agent for high-pressure drilling fluid comprises the following components in parts by weight: 16 parts nutshell, 18 parts basalt fiber, 11 parts phenolic resin, 13 parts silicone modified epoxy resin, 3 parts polyoxyethylene fatty alcohol ether, 12 parts carboxymethyl hydroxyethyl cellulose, 1 part polyvinyl alcohol, 75 parts cement, 150 parts water; The preparation method of the fruit shell-containing plugging agent for drilling fluid comprises the following steps: The fruit shells and cement are mixed and ball-milled, and then the remaining components are added and blended, and stirred at 1100 r / min for 35 minutes to obtain a fruit shell-containing plugging agent for drilling fluid.

[0025] Example 3 A fruit shell-containing plugging agent for high-pressure drilling fluid comprises the following components in parts by weight: 20 parts of fruit shells, 25 parts of basalt fiber, 14 parts of phenolic resin, 15 parts of silicone-modified epoxy resin, 6 parts of polyoxyethylene fatty alcohol ether, 16 parts of carboxymethyl hydroxyethyl cellulose, 1.5 parts of polyvinyl alcohol, 80 parts of cement, and 150 parts of water; The preparation method of the fruit shell-containing plugging agent for drilling fluid comprises the following steps: The fruit shells and cement are mixed and ball-milled, and then the remaining components are added and blended, and stirred at 1200 r / min for 25 minutes to obtain a fruit shell-containing plugging agent for drilling fluid.

[0026] Example 4 The only difference between this embodiment and embodiment 2 is that in this embodiment, 25 parts of basalt fiber and 5 parts of carboxymethyl hydroxyethyl cellulose are added.

[0027] Example 5 The only difference between this embodiment and embodiment 2 is that in this embodiment, 24 parts of basalt fiber and 6 parts of carboxymethyl hydroxyethyl cellulose are added.

[0028] Example 6 The only difference between this embodiment and embodiment 2 is that in this embodiment, 20 parts of basalt fiber and 10 parts of carboxymethyl hydroxyethyl cellulose are added.

[0029] Example 7 The only difference between this embodiment and Example 6 is that in this embodiment, the basalt fiber is modified basalt fiber, and the raw materials of the modified basalt fiber include basalt fiber and polyacrylate. The preparation method of the modified basalt fiber includes the following steps: dissolving 5 parts of polyacrylate in ethyl acetate to obtain a polyacrylate solution with a mass fraction of 4%, adding 15 parts of basalt fiber to the 4% polyacrylate solution, uniformly dispersing, concentrating, and drying to obtain modified basalt fiber.

[0030] Example 8 The only difference between this embodiment and Example 6 is that in this embodiment, the basalt fiber is modified basalt fiber, the raw materials of the modified basalt fiber include basalt fiber and rectorite, and the preparation method of the modified basalt fiber includes the following steps: blending 15 parts of basalt fiber and 5 parts of rectorite, grinding, to obtain modified basalt fiber.

[0031] Example 9 The only difference between this embodiment and embodiment 6 is that in this embodiment, the basalt fiber is modified basalt fiber, the raw materials of the modified basalt fiber include basalt fiber, rectorite and polyacrylate, and the preparation method of the modified basalt fiber includes the following steps: A1. Blending 15 parts of basalt fiber and 3.75 parts of rectorite, and grinding to obtain a mixture; A2. Dissolve 1.25 parts of polyacrylate in ethyl acetate to obtain a 4% by mass polyacrylate solution. Add the mixture to the 4% by mass polyacrylate solution, disperse evenly, concentrate, and dry to obtain modified basalt fiber.

[0032] Example 10 The only difference between this embodiment and embodiment 9 is that in this embodiment, 19 parts of basalt fiber, 0.75 parts of rectorite, and 0.25 parts of polyacrylate are added.

[0033] Example 11 The only difference between this embodiment and embodiment 9 is that in this embodiment, 16 parts of basalt fiber, 3 parts of rectorite, and 1 part of polyacrylate are added.

[0034] Example 12 The only difference between this embodiment and embodiment 9 is that in this embodiment, 18 parts of basalt fiber, 1.5 parts of rectorite, and 0.5 parts of polyacrylate are added.

[0035] Comparative Example 1 The only difference between this comparative example and Example 1 is that in this comparative example, no carboxymethyl hydroxyethyl cellulose is added, and 18 parts of basalt fiber are added.

[0036] Comparative Example 2 The only difference between this comparative example and Example 1 is that in this comparative example, no basalt fiber is added, and 18 parts of carboxymethyl hydroxyethyl cellulose is added.

[0037] Comparative Example 3 The only difference between this comparative example and Example 1 is that in this comparative example, neither basalt fiber nor carboxymethyl hydroxyethyl cellulose was added.

[0038] Experimental Example 1 Rheological properties test The drilling fluids prepared in Examples 1 to 3 were subjected to rheological property tests using a fruit shell-containing plugging agent. The test results are shown in Table 1 below.

[0039] Table 1 Rheological properties test results

[0040] In Table 1, the apparent viscosity and plastic viscosity of the fruit shell-containing plugging agent for drilling fluid prepared in Examples 1 to 3 are relatively small, indicating that the fruit shell-containing plugging agent for drilling fluid prepared by the present invention has low viscosity, good rheological properties, can adapt to gaps of different sizes, and has a good plugging effect.

[0041] Experimental Example 2: Pressure bearing performance and sealing performance test The drilling fluid plugging agents containing fruit shells prepared in Examples 1 to 12 and Comparative Examples 1 to 3 were tested for pressure bearing capacity and leakage under 3 mm and 5 mm cracks, respectively, with reference to SY / T 5840-2007 "Indoor Test Methods for Bridging Plugs for Drilling Fluids". The pressure bearing capacity and leakage test were conducted at a temperature of 150° C. under a 3 mm crack, and at a temperature of 130° C. under a 5 mm crack. The test results are shown in Table 2 below.

[0042] Table 2 Test results of pressure bearing performance and plugging performance

[0043] In Table 2, compared with Comparative Examples 1 to 3, the leakage of the fruit shell-containing plugging agent for drilling fluid prepared in Example 1 under 3 mm and 5 mm cracks is significantly reduced, and the pressure bearing capacity is significantly improved, indicating that when the raw materials of the fruit shell-containing plugging agent for drilling fluid include basalt fiber and carboxymethyl hydroxyethyl cellulose, the two have a synergistic effect, which can significantly improve the pressure bearing capacity and plugging effect of the fruit shell-containing plugging agent for drilling fluid.

[0044] Compared with Examples 2 and 4, the fruit shell-containing plugging agent for drilling fluid prepared in Examples 5-6 has reduced leakage under 3 mm and 5 mm cracks and improved pressure bearing capacity, indicating that when the weight ratio of basalt fiber to carboxymethyl hydroxyethyl cellulose is 2-4:1, the pressure bearing capacity and plugging effect of the fruit shell-containing plugging agent for drilling fluid can be further improved.

[0045] Compared with Examples 6-8, the nutshell-containing plugging agents for drilling fluid prepared in Examples 9-12 showed reduced leakage at 3mm and 5mm cracks and improved pressure bearing capacity, indicating that modifying basalt fiber with rectorite and polyacrylate can further improve the pressure bearing capacity and plugging effect of the nutshell-containing plugging agent for drilling fluid. In addition, compared with Examples 9-10, the nutshell-containing plugging agents for drilling fluid prepared in Examples 11-12 showed reduced leakage at 3mm and 5mm cracks and improved pressure bearing capacity, indicating that when the weight ratio of basalt fiber, rectorite, and polyacrylate is 8-18:1.5:0.5, the pressure bearing capacity and plugging effect of the nutshell-containing plugging agent for drilling fluid can be further improved.

[0046] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A fruit shell-containing plugging agent for high-pressure drilling fluid, characterized in that: The composition comprises the following components in parts by weight: 12-20 parts of fruit shells, 15-25 parts of basalt fibers, 8-14 parts of phenolic resin, 10-15 parts of silicone-modified epoxy resin, 1-6 parts of surfactant, 3-16 parts of carboxymethyl hydroxyethyl cellulose, 0.5-1.5 parts of tackifier, 70-80 parts of cement, and 150 parts of water.

2. The fruit shell-containing plugging agent for high-pressure drilling fluid according to claim 1, characterized in that: The weight ratio of the basalt fiber to the carboxymethyl hydroxyethyl cellulose is 2-4:

1.

3. The fruit shell-containing plugging agent for high-pressure drilling fluid according to claim 1, characterized in that: The basalt fiber is a modified basalt fiber, and the raw materials of the modified basalt fiber include basalt fiber, rectorite and polyacrylate.

4. The fruit shell-containing plugging agent for high-pressure drilling fluid according to claim 3, characterized in that: The weight ratio of the basalt fiber, rectorite and polyacrylate is 8-18:1.5:0.

5.

5. The fruit shell-containing plugging agent for high-pressure drilling fluid according to claim 3, characterized in that: The preparation method of the modified basalt fiber comprises the following steps: A1. blending the basalt fiber and the rectorite, and grinding to obtain a mixture; A2. Dissolving the polyacrylate in ethyl acetate to obtain a polyacrylate solution, adding the mixture to the polyacrylate solution, dispersing the mixture evenly, concentrating, and drying to obtain modified basalt fiber.

6. The fruit shell-containing plugging agent for high-pressure drilling fluid according to claim 1, characterized in that: The fruit shell is one or more of peanut shell, walnut shell and cottonseed shell.

7. The fruit shell-containing plugging agent for high-pressure drilling fluid according to claim 1, characterized in that: The surfactant is one or more of polyoxyethylene fatty alcohol ether, sucrose fatty acid ester, and octylphenol polyoxyethylene ether.

8. The fruit shell-containing plugging agent for high-pressure drilling fluid according to claim 1, characterized in that: The tackifier is one or both of polyvinyl alcohol and xanthan gum.

9. The method for preparing a fruit shell-containing plugging agent for high-pressure drilling fluid according to any one of claims 1 to 8, characterized in that: The method comprises the following steps: mixing the fruit shell and the cement, performing ball milling, adding the remaining components, blending, and stirring to obtain a fruit shell-containing plugging agent for drilling fluid.

10. The method for preparing a fruit shell-containing plugging agent for high-pressure drilling fluid according to claim 9, characterized in that: During the stirring, the stirring speed is 1000-1100 r / min, and the stirring time is 25-45 min.

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