Extraction drill hole plugging method based on liquid silicone rubber and SPA super absorbent resin

Abstract

The invention provides an extraction drill hole plugging method based on liquid silicone rubber and SPA (superabsorbent polymer), which comprises the following steps: respectively sleeving air bags at the front end and the tail end of a gas extraction pipe, extending a material injection pipe between the two air bags, communicating the two air bags through a gas injection pipe, feeding one end of the gas extraction pipe into a gas extraction drill hole, and sealing the gas extraction drill hole; sPA super absorbent resin particles are injected into the two air bags through an air injection pipe, and after a certain amount of SPA super absorbent resin particles are filled, air injection is changed until the air bags expand to meet the requirement; then water is injected into the two air bags through the air injection pipe, the SPA super absorbent resin absorbs water and expands, and a tighter plug is formed; and liquid silicone rubber and SPA super absorbent resin composite liquid is injected into the gas extraction drill hole through the material injection pipe till plugging is completed. The problems that a traditional plugging material and a traditional plugging method are insufficient in sealing performance, poor in water absorption expansibility or insufficient in durability and the like are solved. Belongs to the technical field of plugging materials.

Description

Technical Field

[0001] The invention relates to a method for plugging an extraction borehole based on liquid silicone rubber and SPA super absorbent resin, and belongs to the technical field of plugging materials. Background Art

[0002] The quality of the drilling hole seal directly determines the efficiency and stability of the gas extraction system. Once the drilling hole seal fails during the extraction process, the outside air will have the opportunity to penetrate into the borehole, causing gas leakage. This leakage will not only cause the gas concentration in the extraction pipeline to drop rapidly, but may also cause a series of safety problems and increase the risk of gas explosion. Since the gas concentration is reduced due to the failure of the seal, the extracted gas cannot be raised to a usable concentration level. This means that a large amount of gas that could have been used as clean energy will be directly discharged into the atmosphere, which not only causes a huge waste of resources, but also causes serious pollution to the environment.

[0003] Traditional plugging materials often have problems such as insufficient sealing, poor water absorption and expansion, or insufficient durability when dealing with complex and changeable plugging environments. To this end, the present invention provides a method for plugging a drainage borehole based on liquid silicone rubber and SPA super absorbent resin. Summary of the invention

[0004] The invention provides a drilling plugging method based on liquid silicone rubber and SPA super absorbent resin to solve the problems of insufficient sealing, poor water absorption and expansion or insufficient durability existing in traditional plugging materials and plugging methods.

[0005] In order to solve the above problems, a method for plugging the extraction borehole based on liquid silicone rubber and SPA super absorbent resin is proposed, which includes:

[0006] Step 1: Laying out the gas extraction pipe: The front end and the rear end of the gas extraction pipe are respectively provided with a first air bag and a second air bag, the injection pipe passes through the second air bag and extends between the second air bag and the first air bag, the injection pipe is provided with a first control valve, and the two air bags are connected through an air injection pipe, the air injection pipe is provided with a second control valve, and then the front end of the gas extraction pipe is sent inwardly into the gas extraction borehole, and the air bag at the rear end is also located in the gas extraction borehole;

[0007] Step 2: Inject SPA super absorbent resin particles into the two air bags through the air injection tube. After a certain amount of filling, stop blowing and replace with air injection until the air bags expand and then stop injecting air; inject water into the two air bags through the air injection tube, and the SPA super absorbent resin absorbs water and expands to form a tighter plug;

[0008] Step 3: Inject liquid silicone rubber and SPA super absorbent resin composite liquid into the gas extraction borehole through the injection pipe until the plugging is completed.

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

[0010] In the above method, the SPA super absorbent resin is sodium polyacrylate, and the weight ratio of the SPA super absorbent resin to water injected into the first airbag and the second airbag is 1:120-150.

[0011] In the above method, the SPA super absorbent resin is a PAAHM type absorbent resin, and the weight ratio of the SPA super absorbent resin to water injected into the first airbag and the second airbag is 1:350-450.

[0012] In the aforementioned method, liquid silicone rubber is also injected into the first airbag and the second airbag, and the weight ratio of the liquid silicone rubber to the SPA super absorbent resin in the airbag is 1:0.2-1. The airbags at both ends mainly face the external environment and the gas side, which require stronger structural stability and durability. Therefore, a lower SPA super absorbent resin ratio is set, so as to improve its pressure resistance and environmental erosion resistance while taking into account the expansion of the material.

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

[0014] 1. The liquid silicone rubber used in the present invention can maintain stable performance in a high temperature environment; it has good fluidity before curing, can penetrate into the tiny gaps of the borehole, and has a small volume change after curing, forming a solid sealing layer, which is tightly adhered to the borehole wall and effectively prevents the penetration of gas and liquid.

[0015] 2. The SAP super absorbent resin added in the present invention expands by absorbing water, and the super absorbent resin can form a tighter sealing layer in the borehole, effectively preventing oxygen from entering the coal seam, thereby indirectly playing a role in inhibiting oxidation. At the same time, it can also absorb the moisture released in the coal seam, reducing the humidity and spontaneous combustion tendency of the coal seam.

[0016] 3. The present invention combines the excellent properties of liquid silicone rubber and SAP super absorbent resin to seal coal seam boreholes, improve the borehole sealing rate, and play a role in blocking.

[0017] The present invention uses the first airbag, the area between the two airbags and the second airbag as the inner section, the middle section and the outer section of the plugging section respectively. At the same time, the proportions of the SPA super absorbent resin, the liquid silicone rubber and the like added in the three sections can be adjusted as needed. For example, the SPA super absorbent resin can be added according to a decreasing proportion trend from the inside to the outside, which can ensure that the plugging material exerts the best performance in different areas. The inner section emphasizes expansion plugging, the middle section balances expansion and strength, and the outer section emphasizes structural stability and durability. Through this design, the optimal performance matching of materials in different areas can be achieved, thereby improving the plugging effect and service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall layout of the present invention.

[0019] In the figure: 1. Coal seam; 2. Fracture zone around the hole; 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 air bag; 10. Second air bag. DETAILED DESCRIPTION

[0020] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0021] Example 1

[0022] This embodiment provides a method for plugging a drainage borehole based on liquid silicone rubber and SPA super absorbent resin, comprising:

[0023] Step 1, laying out the gas extraction pipe: the front end and the rear end of the gas extraction pipe 3 are respectively provided with a first airbag 9 and a second airbag 10, the injection pipe 5 passes through the second airbag 10 and extends between the second airbag 10 and the first airbag 9, the injection pipe 5 is installed with a first control valve 4, and the two airbags are connected through an air injection pipe 7, the air injection pipe 7 is installed with a second control valve 6, and then the front end of the gas extraction pipe 3 is sent inward into the gas extraction borehole 8, and the airbag at the rear end is also located in the gas extraction borehole 8; the airbags are all closed structures, and the airbags are not connected to the gas extraction pipe 3 and the injection pipe 5. When the airbags are manufactured, holes for the corresponding pipelines to pass through can be reserved in advance on the airbags, and the inner wall of the hole is the material of the airbag to keep the airbag sealed. After the airbag is inflated, it is squeezed and sealed with the pipeline passing through the airbag; the airbag is directly connected to the air injection pipe 7.

[0024] Step 2: inject SPA super absorbent resin particles into the two airbags through the air injection pipe 7. After a certain amount of filling, stop blowing and replace with air injection until the airbags are expanded and then stop injecting air; inject water into the two airbags through the air injection pipe 7, so that the SPA super absorbent resin absorbs water and expands to form a tighter plug. The SPA super absorbent resin is selected to use sodium polyacrylate. By weight, the ratio of the SPA super absorbent resin to water injected into the airbag is 1:120-150;

[0025] Step 3: inject a composite liquid of liquid silicone rubber and SPA super absorbent resin into the gas extraction borehole 8 through the injection pipe 5 until plugging is completed. In the composite liquid, the weight ratio of liquid silicone rubber to SPA super absorbent resin is 1:1-2.

[0026] Embodiment 2:

[0027] The difference between this embodiment and embodiment 1 is that in step 2, liquid silicone rubber is also injected into the first airbag 9 and the second airbag 10, and the weight ratio of the liquid silicone rubber to the SPA super absorbent resin in the airbag is 1:0.2-1. The two airbags mainly face the external environment and the gas side, which require stronger structural stability and durability. Therefore, a lower SPA super absorbent resin ratio is set, so as to improve its pressure resistance and environmental corrosion resistance while taking into account the expansion of the material.

[0028] Embodiment 3:

[0029] The difference between this embodiment and embodiment 1 is that the SPA super absorbent resin is a PAAHM type absorbent resin, and the weight ratio of the SPA super absorbent resin to water injected into the airbag is 1:350-450.

[0030] Example 4

[0031] The difference between this embodiment and embodiment 1 is that this embodiment is connected to the first airbag 9 and the second airbag 10 respectively through two air injection pipes 7, and control valves are provided on the two air injection pipes 7. SPA super absorbent resin, water, liquid silicone rubber, etc. are respectively injected into the first airbag 9 and the second airbag 10 through the two air injection pipes 7, so that the proportions of the components injected into the two airbags can be different. During the injection process, the pressure can be monitored by installing a pressure gauge on the external air injection pipe 7 to control the injection amount.

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

[0033] As a result, the inner section (at the first airbag 9) has a high water-absorbent resin ratio. The inner section requires stronger expansion and blocking capabilities to fill the tiny cracks in the hole wall. Therefore, setting a higher SPA high water-absorbent resin ratio can ensure that the material expands rapidly after absorbing water and effectively blocks the tiny cracks.

[0034] The middle section (between the two airbags) has a moderate ratio. As a transition between the inner and outer sections, the middle section needs to balance the expandability and structural stability. Such a ratio can not only ensure a certain expandability, but also provide sufficient structural strength to support the inner section and resist the pressure of the outer section.

[0035] The outer section (at the second airbag 10) has a low water-absorbent resin ratio. The outer section is mainly responsible for contact with the external environment and requires stronger structural stability and durability. Therefore, setting a lower SPA high water-absorbent resin ratio can maintain appropriate material expansion and at the same time greatly improve its pressure resistance and environmental erosion resistance.

[0036] This decreasing trend of SPA super absorbent resin proportion from inside to outside can ensure that the plugging material can perform at its best in different areas. The inner section emphasizes expansion plugging, the middle section balances expansion and strength, and the outer section emphasizes structural stability and durability. Through this design, the optimal performance matching of materials in different areas can be achieved, thereby improving the plugging effect and service life.

[0037] Obviously, the above-mentioned embodiments and comparative examples are only a part of the present invention, rather than all examples. The preferred embodiments of the present invention disclosed above are only used to help explain the present invention, without describing all the details in detail. According to the content of this specification, more modifications and changes can be made. Based on the embodiments and comparative examples in the present invention, all other embodiments and various modifications or supplements obtained by ordinary technicians in the field without making creative work, as long as they do not deviate from the structure of the invention or exceed the scope defined by the claims, belong to the scope of protection of the present invention.

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

Claims

1. A method for plugging a drainage borehole based on liquid silicone rubber and SPA super absorbent resin, characterized in that: Specifically include: Step 1: Laying out the gas extraction pipe: The front end and the rear end of the gas extraction pipe (3) are respectively provided 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 between the second air bag (10) and the first air bag (9), the injection pipe (5) is provided with a first control valve (4), and the two air bags are connected through an air injection pipe (7), the air injection pipe (7) is provided with a second control valve (6), and then the front end of the gas extraction pipe (3) is sent inwardly into the gas extraction borehole (8), and the air bag at the rear end is also located in the gas extraction borehole (8); Step 2: Inject SPA super absorbent resin particles into the two air bags through the air injection pipe (7). After a certain amount of filling, stop blowing and replace with air injection until the air bags expand and then stop injecting air; inject water into the two air bags through the air injection pipe (7), so that the SPA super absorbent resin absorbs water and expands, forming a tighter plug; Step 3: injecting a composite liquid of liquid silicone rubber and SPA super absorbent resin into the gas extraction borehole (8) through the injection pipe (5) until the plugging is completed.

2. According to claim 1, a method for plugging a drainage borehole based on liquid silicone rubber and SPA super absorbent resin is characterized in that: The SPA super absorbent resin is sodium polyacrylate or PAAHM type absorbent resin. In step 3, in the composite liquid injected into the gas extraction borehole (8) through the injection pipe (5), the weight ratio of liquid silicone rubber to SPA super absorbent resin is 1:1-2.

3. A method for plugging a drainage borehole based on liquid silicone rubber and SPA super absorbent resin according to claim 2, characterized in that: The SPA super absorbent resin is sodium polyacrylate. In terms of weight ratio, the ratio of the SPA super absorbent resin to water injected into the first airbag (9) and the second airbag (10) is 1:120-150.

4. The method for plugging a drainage borehole based on liquid silicone rubber and SPA super absorbent resin according to claim 2, characterized in that: The SPA super absorbent resin is a PAAHM type absorbent resin. In terms of weight ratio, the ratio of the SPA super absorbent resin to water injected into the first airbag (9) and the second airbag (10) is 1:350-450.

5. The method for plugging a drainage borehole based on liquid silicone rubber and SPA super absorbent resin according to claim 2, characterized in that: Liquid silicone rubber is also injected into the first airbag (9) and the second airbag (10), and the weight ratio of the liquid silicone rubber to the SPA super absorbent resin in the airbag is 1:0.2-1.

Images