Drilling plugging method based on liquid silicone rubber and sap high water absorbing resin

Abstract

The application provides a kind of based on liquid silicone rubber and SAP high water-absorbing resin extraction borehole plugging method, by being respectively set in the front end and tail end of gas extraction pipe air bag, injection pipe is inserted between two air bags, two air bags are communicated by gas injection pipe, one end of gas extraction pipe is sent into gas extraction borehole, SAP high water-absorbing resin particles are injected into two air bags by gas injection pipe, after filling a certain amount, change injection air, until air bag inflation reaches the requirement;Water is injected into two air bags again through the gas injection pipe, SAP high water-absorbing resin swells to form a more compact plug;Liquid silicone rubber and SAP high water-absorbing resin composite liquid are injected into the gas extraction borehole through the injection pipe until the plugging is completed. To solve the problems of insufficient sealing, poor water absorption and swelling, and insufficient durability of traditional plugging materials and methods. It belongs to the technical field of plugging materials.

Description

TECHNICAL FIELD

[0001] The application relates to a sealing method for gas extraction drilling based on liquid silicone rubber and SAP high water-absorbing resin, and belongs to the technical field of sealing materials. BACKGROUND

[0002] The quality of sealing of the gas extraction drilling directly determines the efficiency and stability of the gas extraction system. Once the sealing of the drilling fails during the extraction process, external air will have the opportunity to penetrate into the drilling, forming a gas leakage phenomenon. This gas leakage not only causes the gas concentration in the extraction pipeline to drop rapidly, but also may cause a series of safety problems, increasing the risk of gas explosion. Due to the sealing failure, the gas extraction cannot be improved to a usable concentration level. This means that a large amount of gas that can be used as clean energy will be directly discharged into the atmosphere, causing a huge waste of resources and serious pollution to the environment.

[0003] The traditional sealing material often has problems such as insufficient sealing, poor water absorption and expansion, or insufficient durability when dealing with complex and variable sealing environments. Therefore, the application provides a sealing method for gas extraction drilling based on liquid silicone rubber and SAP high water-absorbing resin. SUMMARY

[0004] The application provides a sealing method for gas extraction drilling based on liquid silicone rubber and SAP high water-absorbing resin to solve the problems of insufficient sealing, poor water absorption and expansion, or insufficient durability of the traditional sealing material and sealing method.

[0005] To solve the above problems, a sealing method for gas extraction drilling based on liquid silicone rubber and SAP high water-absorbing resin is adopted, which comprises the following steps:

[0006] Step 1, laying a gas extraction pipe: a first air bag and a second air bag are respectively sleeved on the front end and the tail end of the gas extraction pipe, an injection pipe penetrates through the second air bag and extends between the second air bag and the first air bag, a first control valve is installed on the injection pipe, the two air bags are connected in communication through an air injection pipe, a second control valve is installed on the air injection pipe, then the front end of the gas extraction pipe is sent into the gas extraction drilling, and the air bag at the tail end is also located in the gas extraction drilling;

[0007] Step 2, SAP high water-absorbing resin particles are injected into the two air bags through the air injection pipe, after a certain amount of filling, the blowing is stopped, air injection is replaced, and the injection is stopped after the air bag is inflated; water is injected into the two air bags through the air injection pipe, the SAP high water-absorbing resin absorbs water and expands, forming a more compact plug;

[0008] Step 3, liquid silicone rubber and SAP high water-absorbing resin composite liquid are injected into the gas extraction drilling through the injection pipe until the sealing is completed.

[0009] In the aforementioned method, the SAP super absorbent resin is sodium polyacrylate or PAAHM type super absorbent resin. In step three, the ratio of liquid silicone rubber to SAP super absorbent resin by weight is 1:1 to 2 in the composite liquid injected into the gas extraction borehole 8 through the injection pipe.

[0010] In the aforementioned method, the SAP superabsorbent resin is sodium polyacrylate, and the ratio of SAP superabsorbent resin to water injected into the first and second airbags by weight is 1:120 to 150.

[0011] In the aforementioned method, the SAP superabsorbent resin is a PAAHM type superabsorbent resin, and the ratio of SAP superabsorbent resin and water injected into the first and second airbags by weight is 1:350 to 450.

[0012] In the aforementioned method, liquid silicone rubber is also injected into the first and second airbags, and the ratio of liquid silicone rubber to SAP superabsorbent resin in the airbags by weight is 1:0.2 to 1. The airbags at both ends mainly face the external environment and the gas side, which requires stronger structural stability and durability. Therefore, a lower proportion of SAP superabsorbent resin is set, so as to improve its pressure resistance and environmental corrosion resistance while taking into account the material's expansion properties.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] 1. The liquid silicone rubber used in this invention can maintain stable performance under high temperature conditions; it has good fluidity before curing, can penetrate into the tiny gaps in the drilled hole, and has little volume change after curing, forming a strong sealing layer that adheres tightly to the drilled hole wall, effectively preventing the penetration of gas and liquid.

[0015] 2. The SAP superabsorbent polymer (SAP) added in this invention expands upon absorbing water, forming a tighter sealing layer in the borehole, effectively preventing oxygen from entering the coal seam, thus indirectly inhibiting combustion. Simultaneously, it can absorb moisture released from the coal seam, reducing its humidity and spontaneous combustion tendency.

[0016] 3. This invention combines the excellent properties of liquid silicone rubber and SAP superabsorbent resin to seal coal seam boreholes, improve the borehole sealing rate, and play an inhibitory role.

[0017] The first gas bag, the two gas bags and the second gas bag are respectively used as an inner section, a middle section and an outer section of the plugging section, meanwhile, the proportions of SAP superabsorbent resin, liquid silicone rubber and the like added in the three sections can be adjusted according to requirements, for example, the SAP superabsorbent resin can be added according to a decreasing trend from inside to outside, the optimal performance of the plugging material in different regions can be ensured, the inner section emphasizes swelling plugging, the middle section balances swelling and strength, the outer section emphasizes structural stability and durability, through the design, the optimal performance matching of the material in different regions can be realized, and the plugging effect and service life are improved. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a whole layout schematic diagram of the present application.

[0019] In the figure: 1, coal seam; 2, hole peripheral fissure zone; 3, gas extraction pipe; 4, first control valve; 5, injection pipe; 6, second control valve; 7, gas injection pipe; 8, gas extraction borehole; 9, first gas bag; 10, second gas bag. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings, and it should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0021] Example 1

[0022] The present embodiment provides a gas extraction borehole plugging method based on liquid silicone rubber and SAP superabsorbent resin, comprising:

[0023] Step one, laying a gas extraction pipe: the front end and the tail end of the gas extraction pipe 3 are respectively sleeved with a first gas bag 9 and a second gas bag 10, the injection pipe 5 passes through the second gas bag 10 and extends into the space between the second gas bag 10 and the first gas bag 9, the first control valve 4 is installed on the injection pipe 5, the two gas bags are connected through the gas injection pipe 7, the second control valve 6 is installed on the gas injection pipe 7, then the front end of the gas extraction pipe 3 is sent into the gas extraction borehole 8, and the tail end gas bag is also located in the gas extraction borehole 8; the gas bags are all closed structures, the gas bags are not connected with the gas extraction pipe 3 and the injection pipe 5, a hole for the corresponding pipeline to pass through can be reserved on the gas bag when the gas bag is made, the inner wall of the hole is the material of the gas bag to keep the gas bag sealed, and the gas bag is extruded and sealed with the pipeline passing through the gas bag after swelling; the gas bag is directly connected with the gas injection pipe 7.

[0024] Step two, inject SAP super absorbent resin particles into the two air bags through the air injection pipe 7, after filling a certain amount, stop blowing, change to inject air, until the air bag is inflated and stop injecting; inject water into the two air bags through the air injection pipe 7, and the SAP super absorbent resin absorbs water and expands to form a more compact plug, the SAP super absorbent resin is selected to use sodium polyacrylate, and the ratio of the SAP super absorbent resin and water injected into the air bag is 1:120-150 by weight;

[0025] Step three, inject liquid silicone rubber and SAP super absorbent resin composite liquid into the gas extraction borehole 8 through the material injection pipe 5 until the plugging is completed, and in the composite liquid, the ratio of liquid silicone rubber and SAP super absorbent resin is 1:1-2 by weight.

[0026] Example 2:

[0027] The difference between this embodiment and example 1 is that in step two, liquid silicone rubber is also injected into the first air bag 9 and the second air bag 10, and the ratio of liquid silicone rubber and SAP super absorbent resin in the air bag is 1:0.2-1 by weight. The two air bags mainly face the external environment and the gas side, so they need stronger structural stability and durability. Therefore, a lower proportion of SAP super absorbent resin is set, which improves the pressure resistance and environmental erosion resistance of the material while considering the expansibility of the material.

[0028] Example 3:

[0029] The difference between this embodiment and example 1 is that the SAP super absorbent resin is selected to be PAAHM type water absorbing resin, and the ratio of the SAP super absorbent resin and water injected into the air bag is 1:350-450 by weight.

[0030] Example 4

[0031] The difference between this embodiment and example 1 is that two air injection pipes 7 are connected to the first air bag 9 and the second air bag 10 respectively in this embodiment, and control valves are arranged on the two air injection pipes 7. SAP super absorbent resin, water and liquid silicone rubber are injected into the first air bag 9 and the second air bag 10 respectively through the two air injection pipes 7, so that the component ratio injected into the two air bags can be different.

[0032] Specifically, the ratio of liquid silicone rubber, SAP super absorbent resin and water injected into the first air bag 9 is 1:2:130 by weight; the ratio of liquid silicone rubber and SAP super absorbent resin injected into the gas extraction borehole 8 through the material injection pipe 5 is 1:1; and the ratio of liquid silicone rubber, SAP super absorbent resin and water injected into the second air bag 10 is 2-3:1:130.

[0033] Thus, the inner section (at the first air bag 9) has a high proportion of superabsorbent polymer, which needs stronger swelling and plugging capacity to fill the tiny cracks in the hole wall. Therefore, setting a higher proportion of SAP superabsorbent polymer can ensure that the material expands rapidly after absorbing water, effectively plugging the tiny cracks.

[0034] The middle section (between the two air bags) has a moderate proportion of the mixture. The middle section serves as a transition between the inner section and the outer section, and needs to balance the swelling and structural stability. Such a proportion can ensure a certain swelling capacity and provide sufficient structural strength to support the inner section and resist the pressure of the outer section.

[0035] The outer section (at the second air bag 10) has a low proportion of superabsorbent polymer. The outer section is mainly responsible for contact with the external environment, and needs stronger structural stability and durability. Therefore, setting a lower proportion of SAP superabsorbent polymer can maintain appropriate material swelling, while significantly improving its pressure resistance and environmental erosion resistance.

[0036] This decreasing trend of the proportion of SAP superabsorbent polymer from inside to outside can ensure that the plugging material performs optimally in different areas. The inner section emphasizes swelling and plugging, the middle section balances swelling and strength, and the outer section emphasizes structural stability and durability. Through this design, the optimal performance matching of the material in different areas can be achieved, improving the plugging effect and service life.

[0037] Obviously, the above examples and comparative examples are only a part of the present application, not all examples. The preferred embodiments of the present application disclosed above are only used to help explain the present application, without describing all the details. Based on the content of the present specification, more modifications and changes can be made. Based on the examples and comparative examples in the present application, all other examples and various modifications or supplements obtained by those skilled in the art without creative labor, as long as they do not deviate from the structure of the invention or exceed the scope defined by the present claims, belong to the scope of protection of the present application.

[0038] In the present specification, the illustrative expressions of the above terms do not necessarily refer to the same examples and comparative examples. Moreover, the described specific features, structures, materials or characteristics can be combined in any one or more embodiments in a suitable manner.

Claims

1. A method for plugging a drilling extraction based on liquid silicone rubber and SAP superabsorbent resin, characterized in that, Specifically comprising: Step one, gas extraction pipe layout: the front end and tail end of the gas extraction pipe (3) are respectively sleeved with a first air bag (9) and a second air bag (10), the injection pipe (5) passes through the second air bag (10) and extends into the space between the second air bag (10) and the first air bag (9), the first control valve (4) is installed on the injection pipe (5), and the two air bags are connected in communication through the air injection pipe (7), the second control valve (6) is installed on the air injection pipe (7), then the front end of the gas extraction pipe (3) is sent into the gas extraction borehole (8) inwards, and the air bag at the tail end is also located in the gas extraction borehole (8); Step two, SAP super absorbent resin particles are injected into the two air bags through the air injection pipe (7), after a certain amount of filling, blowing is stopped, air injection is replaced, and the injection is stopped until the air bag is inflated; water is injected into the two air bags through the air injection pipe (7), the SAP super absorbent resin absorbs water and expands, and a more compact plug is formed; Step three, liquid silicone rubber and SAP super absorbent resin composite liquid are injected into the gas extraction borehole (8) through the injection pipe (5) until the plugging is completed; The SAP super absorbent resin is polyacrylic acid sodium or PAAHM type water absorbing resin, in step three, the composite liquid injected into the gas extraction borehole (8) through the injection pipe (5) has a weight ratio of liquid silicone rubber to SAP super absorbent resin of 1:1-2.

2. The method according to claim 1, wherein the method is characterized by: The SAP super absorbent resin is polyacrylic acid sodium, and the SAP super absorbent resin and water injected into the first air bag (9) and the second air bag (10) have a weight ratio of 1:120-150.

3. The method according to claim 1, wherein the method is characterized by: The SAP super absorbent resin is PAAHM type water absorbing resin, and the SAP super absorbent resin and water injected into the first air bag (9) and the second air bag (10) have a weight ratio of 1:350-450.

4. The method according to claim 1, wherein the method is characterized by: Liquid silicone rubber is also injected into the first air bag (9) and the second air bag (10), and the weight ratio of the liquid silicone rubber to the SAP super absorbent resin in the air bag is 1:0.2-1.

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