A drilling composite plugging agent, its preparation method and application method

Abstract

This invention discloses a drilling composite plugging agent, its preparation method, and its application method. The drilling composite plugging agent comprises the following components in parts by weight: 30-40 parts modified epoxy resin, 1-2 parts diluent, 4-6 parts curing agent, and 10-14 parts filler. The modified epoxy resin is mainly made from the following raw materials in parts by weight: 20-30 parts epoxy resin, 5-6 parts N-ethylmorpholine, and 4-6 parts polyethylene glycol. Modification of the epoxy resin by N-ethylmorpholine and polyethylene glycol provides basic adhesive properties; N-ethylmorpholine improves the temperature resistance of the epoxy resin; and polyethylene glycol improves the flexibility of the epoxy resin, thereby enhancing the compressive strength of the composite plugging agent. The composite plugging agent obtained by using the modified epoxy resin, diluent, curing agent, and filler in combination has good setting time and high-temperature resistance (i.e., it is not easily carbonized).

Description

Technical Field

[0001] This invention relates to the field of drilling composite plugging agent technology, specifically to a drilling composite plugging agent and its preparation and application methods. Background Technology

[0002] Drilling is the process of using mechanical equipment or manpower to drill holes into the ground. It typically refers to the drilling of wells for exploring or developing liquid and gaseous minerals such as oil and natural gas, as well as large-diameter water supply wells. Drilling has extremely wide applications in national economic development.

[0003] Loss is a common problem encountered during drilling. In severe cases, it can lead to stuck pipe, well collapse, or even the need for filler drilling, resulting in huge economic losses. Therefore, it is necessary to use plugging agents to seal the leak.

[0004] Patent application number CN202010951767.8 describes in its specification that "the high-strength drilling composite plugging agent comprises, by weight, the following components: 5-25 parts of fiber material, 40-60 parts of rigid material, and 15-40 parts of high-strength heat-resistant material; by weight, the high-strength heat-resistant material is made of 10 parts of propylene oxide ether, 5 parts of hydroxyethyl acrylate, 30 parts of glycidyl acrylate, 15 parts of aminophenol, and 40 parts of deionized water." This invention... A novel composite drilling plugging agent is formulated by combining fiber materials, rigid materials, and high-strength, temperature-resistant materials. When applied, it achieves a pressure resistance exceeding 7 MPa and a temperature resistance exceeding 200°C, representing a significant improvement over traditional plugging agents. Furthermore, this composite drilling plugging agent is suitable for both oil-based and water-based drilling fluids. While the composite plugging agent provided by the aforementioned patent can achieve a sealing effect, it takes a long time to form a high-strength sealing zone, has a pressure resistance of only 7 MPa, and carbonization occurs at excessively high temperatures.

[0005] In conclusion, the urgent need to develop a composite drilling plugging agent is a key issue that urgently needs to be addressed in the field of plugging materials technology. Summary of the Invention

[0006] The technical problem to be solved by the present invention is that existing composite sealing agents take a long time to form a high-strength sealing strip, have a pressure resistance of only 7MPa, and will carbonize when the temperature is too high.

[0007] The first objective of this invention is to provide a drilling composite plugging agent, comprising the following components in parts by weight: 30-40 parts modified epoxy resin, 1-2 parts diluent, 4-6 parts curing agent, and 10-14 parts filler;

[0008] The modified epoxy resin is mainly composed of the following raw materials in parts by weight: 20-30 parts epoxy resin, 5-6 parts N-ethylmorpholine, and 4-6 parts polyethylene glycol. The epoxy resin used is one or more of alicyclic epoxy resin, bisphenol A epoxy resin, and amino epoxy resin.

[0009] Epoxy resin was modified with N-ethylmorpholine and polyethylene glycol, and the reaction equation is as follows:

[0010]

[0011] Epoxy resin provides basic adhesive properties; N-ethylmorpholine improves the temperature resistance of epoxy resin; and polyethylene glycol enhances the flexibility of epoxy resin, thereby strengthening the compressive strength of the composite sealant. By combining modified epoxy resin, diluent, curing agent, and filler, the resulting composite sealant exhibits good setting time and high-temperature resistance (i.e., it is not easily carbonized).

[0012] As one possible design, the method for preparing the modified epoxy resin includes:

[0013] The epoxy resin was ground into powder, then mixed with N-ethylmorpholine and reacted at 110-120℃ for 30-40 min to obtain mixture 1;

[0014] Add polyethylene glycol to mixture 1, heat to 140-142°C, and react for 60-90 minutes.

[0015] The modified epoxy resin obtained by this method has good flexibility and temperature resistance.

[0016] As one possible design, the curing agent is mainly composed of the following raw materials in parts by weight: 6-8 parts m-nonylphenol, 4-6 parts acetal resin, and 3-5 parts m-phenylenediamine. m-Nonylphenol improves the flexibility of the curing agent, while m-phenylenediamine improves its curing strength. The acetal resin used is one or more of PVB, PVA, and POM.

[0017] This avoids both excessive brittleness and excessive flexibility of the curing agent.

[0018] As one possible design, the method for preparing the curing agent includes:

[0019] Mix m-nonylphenol, acetal resin and one-third to two-thirds m-phenylenediamine, and react at 80-90°C for 80-90 min to obtain mixture 2;

[0020] Add the remaining m-phenylenediamine to mixture 2, continue the reaction for 120-130 min, then raise the temperature to 140-150℃ and keep it at that temperature for 50 min, and finally dehydrate.

[0021] As one possible design, the diluent is ethylene glycol diglycidyl ether or β-carboxyethyl acrylate.

[0022] As one possible design, the filler is a mixture of glass fiber, quartz sand, and silica.

[0023] As one possible design, the mass ratio of the glass fiber, quartz sand, and silica is 1:1:2 to 3.

[0024] A second objective of this invention is to provide a method for preparing a drilling composite plugging agent, comprising:

[0025] After mixing the modified epoxy resin and diluent, the mixture is heated to 40-50°C, and then filler is added to it and mixed to obtain component A.

[0026] The curing agent is component B.

[0027] As one possible design, the diluent is added to the modified epoxy resin, and the mixture is stirred during the addition process at a speed of 120-130 r / min for 8-10 min.

[0028] The third objective of this invention is to provide a method for using a drilling composite plugging agent, wherein component A and component B are mixed in a mass ratio of 1:1 to 6:1.

[0029] The beneficial effects of this invention are as follows: the drilling composite plugging agent prepared by this invention not only has excellent high strength performance, but also good high temperature resistance and suitable solidification time, thus achieving effective plugging, and is therefore worthy of promotion and use. Attached Figure Description

[0030] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0031] Figure 1 This is a statistical chart of the critical temperature in the performance testing of this invention. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of this invention are only for explaining this invention and are not intended to limit this invention.

[0033] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0034] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. "Several" means one or more, unless otherwise explicitly specified.

[0035] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0036] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0037] Example 1

[0038] The modified epoxy resin was prepared as follows:

[0039] S1. Take 20 parts of bisphenol A epoxy resin, crush it to 100 mesh, and then place it in a reaction vessel;

[0040] S2. Add 5 parts of N-ethylmorpholine to the reactor and heat to 110°C, react for 30 min;

[0041] S3. Add 5 parts of polyethylene glycol, heat to 140°C, react for 60 minutes, and then cool to obtain the modified epoxy resin.

[0042] The curing agent is prepared as follows:

[0043] S1. Add 6 parts of m-nonylphenol, 4 parts of acetal resin and 1 part of m-phenylenediamine to the reaction vessel, then heat to 80℃ and react for 80 min; the acetal resin is a mixture of PVB and PVA, which are mixed in a mass ratio of 1:1.

[0044] S2. Add 2 parts of m-phenylenediamine to the reactor and continue the reaction for 120 minutes. Then raise the temperature to 150°C and keep it at that temperature for 50 minutes. After dehydration, the curing agent is obtained.

[0045] The filler is prepared by mixing glass fiber, quartz sand, and silica in a mass ratio of 1:1:2. In this embodiment, 10 parts of the filler are used. The diluent is ethylene glycol diglycidyl ether, totaling 1 part. In this embodiment, 30 parts of modified epoxy resin and 4 parts of curing agent are used.

[0046] The preparation of a composite plugging agent for drilling is as follows:

[0047] Component A: Place the modified epoxy resin in a stirrer, add the diluent to the stirrer, stir and mix evenly, let stand for 10 minutes, heat to 50℃, add the filler, stir and mix evenly to obtain Component A.

[0048] The stirring speed was 120 r / min, and the stirring time was 8 min.

[0049] Component B: Curing agent.

[0050] The method of using the drilling composite plugging agent is as follows: mix component A and component B in a mass ratio of 6:1 before use.

[0051] The basic performance results of components A and B when used in different proportions are shown in Table 1.

[0052] Table 1: Performance Record of Mixtures of Components A and B at Different Proportions

[0053]

[0054]

[0055] Table 1 shows that the composite sealant exhibits completely different states when the amounts of components A and B are within different ranges. For example, when the ratio of components A to B is 8:1, the mixture will not solidify for a long time after mixing. However, when the ratio of components A to B is 1:2, the resulting composite sealant solidifies quickly but is brittle. Therefore, when the ratio of components A to B is between 1:1 and 6:1, the resulting composite sealant can achieve a two-hour compressive strength of 24 MPa and a critical temperature of 280℃, demonstrating significant compressive strength and high-temperature resistance.

[0056] Example 2

[0057] The modified epoxy resin was prepared as follows:

[0058] S1. Take 25 parts of amino epoxy resin, crush it to 100 mesh, and then place it in a reaction vessel;

[0059] S2. Add 6 parts of N-ethylmorpholine to the reactor and heat to 115℃, react for 35 min;

[0060] S3. Add 5 parts of polyethylene glycol, heat to 141°C, react for 75 minutes, and then cool to obtain the modified epoxy resin.

[0061] The curing agent is prepared as follows:

[0062] S1. Add 7 parts of m-nonylphenol, 5 parts of acetal resin and 1.3 parts of m-phenylenediamine to the reaction vessel, then heat to 85℃ and react for 85 minutes; the acetal resin is obtained by mixing PVB, PVA and POM in a mass ratio of 1:1:1.

[0063] S2. Add 2.7 parts of m-phenylenediamine to the reactor and continue the reaction for 125 minutes. Then raise the temperature to 150°C and keep it at that temperature for 50 minutes. After dehydration, the curing agent is obtained.

[0064] The filler was prepared by mixing glass fiber, quartz sand, and silica in a mass ratio of 1:1:2. In this embodiment, 12 parts of the filler were used. The diluent was ethylene glycol diglycidyl ether, totaling 2 parts. In this embodiment, 35 parts of modified epoxy resin and 5 parts of curing agent were used.

[0065] The preparation of a composite plugging agent for drilling is as follows:

[0066] Component A: Place the modified epoxy resin in a stirrer, add the diluent to the stirrer, stir and mix evenly, let stand for 10 minutes, heat to 50℃, add the filler, stir and mix evenly to obtain Component A.

[0067] The stirring speed was 125 r / min, and the stirring time was 9 min.

[0068] Component B: Curing agent.

[0069] The method of using the drilling composite plugging agent is as follows: mix component A and component B in a mass ratio of 6:1 before use.

[0070] Example 3

[0071] The modified epoxy resin was prepared as follows:

[0072] S1. Take 30 parts of amino epoxy resin, crush it to 100 mesh, and then place it in a reaction vessel;

[0073] S2. Add 6 parts of N-ethylmorpholine to the reactor and heat to 120°C, reacting for 35 minutes;

[0074] S3. Add 6 parts of polyethylene glycol, heat to 142°C, react for 90 minutes, and then cool to obtain the modified epoxy resin.

[0075] The curing agent is prepared as follows:

[0076] S1. Add 8 parts of m-nonylphenol, 6 parts of acetal resin and 1.7 parts of m-phenylenediamine to the reactor, then heat to 85°C and react for 85 minutes; the acetal resin is obtained by mixing PVB and POM, and the mass ratio of the three is 1:1.

[0077] S2. Add 3.3 parts of m-phenylenediamine to the reactor and continue the reaction for 130 min. Then raise the temperature to 150℃ and keep it at that temperature for 50 min. After dehydration, the curing agent is obtained.

[0078] The filler was prepared by mixing glass fiber, quartz sand, and silica in a mass ratio of 1:1:2. In this embodiment, 14 parts of the filler were used. The diluent was β-carboxyethyl acrylate, totaling 2 parts. In this embodiment, 40 parts of modified epoxy resin and 6 parts of curing agent were used.

[0079] The preparation of a composite plugging agent for drilling is as follows:

[0080] Component A: Place the modified epoxy resin in a stirrer, add the diluent to the stirrer, stir and mix evenly, let stand for 10 minutes, heat to 50℃, add the filler, stir and mix evenly to obtain Component A.

[0081] The stirring speed was 125 r / min, and the stirring time was 9 min.

[0082] Component B: Curing agent.

[0083] The method of using the drilling composite plugging agent is as follows: mix component A and component B in a mass ratio of 6:1 before use.

[0084] Comparison Example

[0085] 10 parts by mass of propylene oxide ether, 5 parts by mass of hydroxyethyl acrylate, 30 parts by mass of glycidyl acrylate, 15 parts by mass of aminophenol, and 40 parts by mass of deionized water were mixed and reacted at 80°C for 4 hours to obtain an initial mixed solution. After natural cooling, 1.5% sodium hydroxide solution (10% by mass of the initial mixed solution) was added and the mixture was reacted at 50°C for 4 hours. After natural cooling, the mixture was washed with water and dried to obtain a high-strength heat-resistant material. 25 parts of the high-strength heat-resistant material, 10 parts of sepiolite fiber, 5 parts of carbon fiber, 10 parts of river sand, 30 parts of limestone, and 20 parts of mica flakes were mixed to obtain a composite sealing agent. The particle size of the prepared composite sealing agent was 10-20 mesh.

[0086] Performance testing:

[0087] Composite sealing agents were prepared using the methods of Examples 1, 2, and 3, respectively, and were designated as Experiment 1, Experiment 2, and Experiment 3, with the control example serving as the control group.

[0088] 1) The composite plugging agents prepared by each group were used for drilling and plugging. The compressive strength performance of each group was tested and the relevant data were recorded in Table 2.

[0089] The compressive strength test method is as follows: When a specimen fails under longitudinal pressure without lateral confinement, the load per unit area is called the compressive strength of the specimen. That is, the ratio of the maximum load at failure to the cross-sectional area perpendicular to the loading direction. The compressive strength test is applicable to various solid samples that can be made into regular specimens. Specific experimental steps: After aging the material in a reactor for a certain time to obtain a solidified body, place the solidified body in the center of the pressure plate of the testing machine. Adjust the spherical seat to ensure uniform contact between the two end faces of the specimen. Apply load at a rate of 0.15–1.0 MPa per second until the specimen fails. Record the failure load and the phenomena observed during the loading process. The experimental temperature is 100℃.

[0090] The compressive strength of the sample is calculated using the following formula:

[0091]

[0092] Where: Rc—experimental value of uniaxial compressive strength of rock, kPa; Pc—maximum load value at specimen failure, kN; A—cross-sectional area of ​​specimen, m² 2 .

[0093] Table 2: Record of compressive strength performance for each group

[0094]

[0095] As shown in Table 2, compared with the control group, the compressive strength of the experimental groups (experimental group 1, experimental group 2 and experimental group 3) is better than that of the control group, and the difference between the experimental groups is not significant. The high-strength drilling composite plugging agent provided by the present invention has excellent compressive strength performance.

[0096] The composite plugging agents prepared in each group were used for drilling and plugging, and the temperature resistance of each group was tested. The relevant data are recorded in Table 3.

[0097] The method for determining the critical temperature is as follows: at different temperatures, the composite sealing agent is aged in the reactor for 2 hours. The solidified body is then removed and observed to see if it can solidify. The solidified body is a dense solid. The temperature at which it cannot solidify, the final product is hollow, or the volume is greatly reduced is the critical temperature.

[0098] Table 3: Critical Temperature Records for Each Group

[0099] Group n Critical temperature (°C) Experiment 1 Group 5 309 Experiment 2 group 5 315 Experimental Group 3 5 312 control group 5 250

[0100] From Table 3 and Figure 1 It can be seen that, compared with the control group, the temperature resistance of the experimental groups (experimental group 1, experimental group 2 and experimental group 3) is better than that of the control group, and the difference in temperature resistance among the experimental groups is not significant. The high-strength drilling composite plugging agent provided by the present invention has good temperature resistance.

[0101] It should be noted that all the above embodiments belong to the same inventive concept, and the descriptions of each embodiment have different focuses. Where the description in a particular embodiment is not detailed, please refer to the description in other embodiments.

[0102] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A drilling composite plugging agent, characterized in that, It includes the following components in parts by weight: 30-40 parts modified epoxy resin, 1-2 parts diluent, 4-6 parts curing agent, and 10-14 parts filler; The modified epoxy resin is mainly made from the following raw materials in parts by weight: 20-30 parts epoxy resin, 5-6 parts N-ethylmorpholine, and 4-6 parts polyethylene glycol.

2. The drilling composite plugging agent according to claim 1, characterized in that, The preparation method of the modified epoxy resin includes: The epoxy resin was ground into powder, then mixed with N-ethylmorpholine and reacted at 110-120℃ for 30-40 min to obtain mixture 1; Add polyethylene glycol to mixture 1, heat to 140-142°C, and react for 60-90 minutes.

3. The drilling composite plugging agent according to claim 1, characterized in that, The curing agent is mainly made from the following raw materials in parts by weight: 6-8 parts of m-nonylphenol, 4-6 parts of acetal resin, and 3-5 parts of m-phenylenediamine.

4. The drilling composite plugging agent according to claim 3, characterized in that, The method for preparing the curing agent includes: Mix m-nonylphenol, acetal resin and one-third to two-thirds m-phenylenediamine, and react at 80-90°C for 80-90 min to obtain mixture 2; Add the remaining m-phenylenediamine to mixture 2, continue the reaction for 120-130 min, then raise the temperature to 140-150℃ and keep it at that temperature for 50 min, and finally dehydrate.

5. The drilling composite plugging agent according to claim 1, characterized in that, The diluent is ethylene glycol diglycidyl ether or β-carboxyethyl acrylate.

6. The drilling composite plugging agent according to claim 1, characterized in that, The filler is a mixture of glass fiber, quartz sand and silica.

7. The drilling composite plugging agent according to claim 6, characterized in that, The mass ratio of glass fiber, quartz sand and silicon dioxide is 1:1:2 to 3.

8. A method for preparing the drilling composite plugging agent according to any one of claims 1-7, characterized in that, The preparation method includes: After mixing the modified epoxy resin and diluent, the temperature is raised to 40-50°C, and then filler is added to the mixture to obtain component A. The curing agent is component B.

9. The preparation method according to claim 8, characterized in that, Add the diluent to the modified epoxy resin and stir during the addition process. The stirring speed is 120-130 r / min and the stirring time is 8-10 min.

10. A method of using the drilling composite plugging agent obtained by the preparation method of claim 8 or 9, characterized in that, Mix component A and component B in a mass ratio of 1:1 to 6:1.

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