CN114704227B - Method for splitting and mining raw coal and structural coal by using composite coal bed gas pressure - Google Patents
Method for splitting and mining raw coal and structural coal by using composite coal bed gas pressure Download PDFInfo
- Publication number
- CN114704227B CN114704227B CN202210368863.9A CN202210368863A CN114704227B CN 114704227 B CN114704227 B CN 114704227B CN 202210368863 A CN202210368863 A CN 202210368863A CN 114704227 B CN114704227 B CN 114704227B
- Authority
- CN
- China
- Prior art keywords
- horizontal well
- coal
- fracturing
- structural
- upper horizontal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 239000003245 coal Substances 0.000 title claims abstract description 162
- 239000002131 composite material Substances 0.000 title claims abstract description 22
- 238000000034 method Methods 0.000 title claims abstract description 20
- 238000005065 mining Methods 0.000 title claims abstract description 16
- 238000010276 construction Methods 0.000 claims abstract description 18
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 13
- 238000005553 drilling Methods 0.000 claims abstract description 10
- 230000009466 transformation Effects 0.000 claims abstract description 6
- 239000012530 fluid Substances 0.000 claims description 16
- 230000015572 biosynthetic process Effects 0.000 claims description 12
- 239000011435 rock Substances 0.000 claims description 3
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 abstract description 16
- 239000007789 gas Substances 0.000 description 32
- 238000003795 desorption Methods 0.000 description 9
- 239000006004 Quartz sand Substances 0.000 description 6
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 6
- 230000008901 benefit Effects 0.000 description 5
- 239000004568 cement Substances 0.000 description 5
- 230000005012 migration Effects 0.000 description 4
- 238000013508 migration Methods 0.000 description 4
- 239000003795 chemical substances by application Substances 0.000 description 3
- 238000006073 displacement reaction Methods 0.000 description 3
- 230000001737 promoting effect Effects 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 230000035699 permeability Effects 0.000 description 2
- 239000004576 sand Substances 0.000 description 2
- 238000009825 accumulation Methods 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000003345 natural gas Substances 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 238000002407 reforming Methods 0.000 description 1
- 230000001131 transforming effect Effects 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/006—Production of coal-bed methane
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/25—Methods for stimulating production
- E21B43/26—Methods for stimulating production by forming crevices or fractures
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/25—Methods for stimulating production
- E21B43/26—Methods for stimulating production by forming crevices or fractures
- E21B43/267—Methods for stimulating production by forming crevices or fractures reinforcing fractures by propping
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/30—Specific pattern of wells, e.g. optimising the spacing of wells
- E21B43/305—Specific pattern of wells, e.g. optimising the spacing of wells comprising at least one inclined or horizontal well
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21F—SAFETY DEVICES, TRANSPORT, FILLING-UP, RESCUE, VENTILATION, OR DRAINING IN OR OF MINES OR TUNNELS
- E21F7/00—Methods or devices for drawing- off gases with or without subsequent use of the gas for any purpose
Landscapes
- Engineering & Computer Science (AREA)
- Mining & Mineral Resources (AREA)
- Geology (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Physics & Mathematics (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- General Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Solid Fuels And Fuel-Associated Substances (AREA)
Abstract
The invention provides a raw coal and structural coal composite coal bed gas pressure splitting mining method, which is characterized in that drilling, casing running and fixing of a horizontal well are respectively carried out on lower strata of an upper raw coal bed and a lower structural coal bed to obtain an upper horizontal well and a lower horizontal well, and the drilling directions of the upper horizontal well and the lower horizontal well are opposite; performing cluster fracturing sections and perforation operations of each cluster fracturing section on the upper horizontal well and the lower horizontal well, wherein the cluster fracturing sections of the upper horizontal well and the cluster fracturing sections of the lower horizontal well are staggered; and performing clustered fracturing construction on the lower horizontal well and the upper horizontal well, utilizing the upper horizontal well to produce gas, and utilizing the lower horizontal well to drain water. The method is suitable for fracturing transformation and coalbed methane exploitation of the composite coal bed consisting of the primary structural coal at the upper part and the structural coal at the lower part.
Description
Technical Field
The invention belongs to the technical field of coal seam gas fracturing, and particularly relates to a method for splitting and mining raw coal and structural coal by using composite coal seam gas.
Background
Coal bed gas commonly called as "gas" is a mineral resource associated with coal, and its main component is methane, which is mainly adsorbed on the surface of coal matrix particles, and partially dissociated in coal pores or dissolved in coal bed water. Is an important unconventional natural gas. The coalbed methane resources in China can be mainly divided into four coalbed methane gathering areas of northeast, north China, northwest and south China. The south gas area is mainly distributed in the south-Qian-West-Yundong area, and the late two-fold coal-bearing stratum with large thickness, more layers and high gas content is intensively distributed to form a key strategic succession area for coal bed gas exploration and development.
The southern coalbed methane accumulation area is most typical of a two-fold Longtan group coal reservoir in Guizhou province. Guizhou coalbed methane geological resource quantity exceeds 3 trillion m 3 The third place is close to 10% of the total national resources. However, the development level of the coalbed methane resource in Guizhou province is wholly behind, the basic theory is insufficient, and a development technology system suitable for the basic theory is not formed. In the Guizhou coal reservoirs, there is a coal seam with a relatively high coal thickness (typically between 5-10m, locally even thicker) and a relatively high gas content. Because the overall strength of Guizhou coal seams is relatively low, such seams are typically composite seams comprised of upper primary structural coal and lower structural crushed coal. According to the prior art, a horizontal well is adopted to drill and fracture in an original structural coal seam, but the well drilling in the structural coal seam is difficult, and the fracture is difficult to reform. If only the primary structural coal on the upper part of the composite coal bed is developed, the amount of available resources is small, and the productivity advantage is difficult to form. Some current techniques suggest performing indirect fracturing of a formation coal seam, i.e., fracturing through the upper roof of the primary structural coal. However, the fracturing technology can only indirectly reform the primary structural coal, has limited influence on structural coal at the lower part of the composite coal bed, and has difficult effect of effectively developing coal bed gas. Therefore, the existing fracturing transformation and exploitation method must be improved, not only can play a role in effectively transforming the primary structural coal seam, but also can effectively relieve pressure for the structural coal seam so as to achieve the purpose of promoting desorption and migration of gas in the structural coal seam.
Disclosure of Invention
In order to solve the problems in the prior art, the invention provides a method for splitting and mining the raw coal and structural coal by using the composite coal bed gas pressure, so that the mining mode can not only play a role in effectively reforming the raw structural coal bed, but also can effectively relieve pressure on the structural coal bed, thereby achieving the purpose of promoting desorption and migration of gas in the structural coal bed.
The invention solves the technical problems by adopting the following technical scheme:
the invention aims to provide a gas pressure splitting mining method for a raw coal and structural coal composite coal seam, which is characterized in that drilling, casing running and fixing of a horizontal well are respectively carried out on a lower stratum of an upper raw coal seam and a lower structural coal seam to obtain an upper horizontal well and a lower horizontal well, and the drilling directions of the upper horizontal well and the lower horizontal well are opposite;
performing cluster fracturing sections and perforation operations of each cluster fracturing section on the upper horizontal well and the lower horizontal well, wherein the cluster fracturing sections of the upper horizontal well and the cluster fracturing sections of the lower horizontal well are staggered;
performing clustered fracturing construction on the lower horizontal well, and performing pressure relief and reverse drainage of fracturing fluid through a shaft after the construction is finished so as to realize sufficient pressure relief on an underlying stratum and a structural coal bed;
performing clustered fracturing construction on the upper horizontal well, and performing pressure relief and reverse drainage of fracturing fluid through a shaft after construction so as to realize pressure relief of the primary coal seam;
and (3) utilizing the upper horizontal well to produce gas and utilizing the lower horizontal well to drain water.
Further, the well bore of the upper horizontal well is arranged in the middle of the primary coal seam and is offset upwards.
Further, the upper horizontal well is disposed a distance of 0.8-1.2 m above the raw coal-structural coal interface.
Further, the upper horizontal well is parallel to the raw coal-to-formation coal interface or to the syncline axis of the syncline basin.
Further, the length of the upper horizontal well is 500-5000 m, and the length of the upper horizontal well is proportional to the thickness of the coal seam.
Further, the lower horizontal well is disposed a distance of 0.8-1.2 m above the formation coal-floor formation interface.
Further, the lower horizontal well is parallel to the formation coal-floor formation interface, or to the syncline axis of the syncline basin.
Further, the distance between the clustered fracturing sections of two adjacent upper horizontal wells is 10-15 m, and the distance between the clustered fracturing sections of two adjacent upper horizontal wells is inversely proportional to the thickness of the primary coal seam.
Furthermore, each clustered fracturing stage perforation of the upper horizontal well adopts directional perforation, and the included angle between each clustered fracturing stage perforation of the upper horizontal well and the primary coal seam layer surface is less than or equal to +/-30 degrees.
Further, the distance between the clustered fracturing sections of two adjacent lower horizontal wells is 10-20 m, and the distance between the clustered fracturing sections of two adjacent lower horizontal wells is inversely proportional to the thickness of the constructed coal seam.
Furthermore, each clustered fracturing stage perforation of the lower horizontal well adopts directional perforation, and each clustered fracturing stage perforation of the lower horizontal well is uniformly arranged at the upper part of the lower horizontal well.
Furthermore, quartz sand is used as a propping agent and active water fracturing fluid is used when the lower horizontal well and the upper horizontal well are subjected to clustered fracturing construction.
Further, the fracturing fluid is a pad fluid-sand carrying fluid-displacement fluid combined fracturing fluid.
Further, the propping agent adopts a composition of quartz sand and ceramsite, and the mass ratio of the quartz sand to the ceramsite is 3.8-4.2.
Compared with the prior art, the invention has the beneficial technical effects that:
the invention performs the sequential fracturing of the upper horizontal well and the lower horizontal well based on the pressure relief requirement. Before the primary structure coal is fractured, the lower horizontal well is clustered to create a pressure relief area for releasing stress, so that the fracturing and desorption of the coal bed are facilitated, and meanwhile, the pressure relief of the lower part of the constructed coal bed is beneficial to the desorption of gas in the coal bed and then the gas is transferred into cracks of the primary coal bed.
The invention realizes indirect fracturing and up-down combined pressure relief of the constructed coal seam. Before the gas exploitation of the structural coal seam is carried out, the gas exploitation of the structural coal seam is realized through indirect fracturing, namely, the fracturing pressure relief of the underlying stratum (the bottom plate rock layer) is realized, and the fracturing pressure relief of the primary structural coal at the upper part is realized, so that the aim of reducing the pressure of the reservoir layer of the structural coal seam to promote the desorption and further development of the gas of the structural coal seam is fulfilled.
The invention fully considers the respective drainage and production advantages of the upper horizontal well and the lower horizontal well. The double-layer horizontal well is utilized, and the respective action advantages of the two-layer horizontal well and the respective migration performance of water and gas are fully considered, namely, the upper horizontal well mainly produces gas and the lower horizontal well mainly discharges water.
The foregoing description is only an overview of the present invention, and is intended to be implemented in accordance with the teachings of the present invention in order that the same may be more clearly understood and to make the same and other objects, features and advantages of the present invention more readily apparent.
Drawings
FIG. 1 is a schematic diagram of a system for gas pressure splitting mining method of a composite coal seam of raw coal and structural coal.
FIG. 2 is a longitudinal cross-sectional view of the upper horizontal well perforations of the method for producing the gas-pressure split of the primary coal and structural coal composite coal seam of the present invention.
FIG. 3 is a longitudinal cross-sectional view of the lower horizontal well perforation of the method for splitting and mining the raw coal and structural coal by using the composite coalbed pressure according to the invention.
In the drawing, 1 is an overburden layer, 2 is a primary coal layer, 3 is a structural coal layer, 4 is a underburden layer, 5 is an upper horizontal well, 6 is a lower horizontal well, 7 is a primary coal-structural coal interface, 8 is a structural coal-floor stratum interface, 9 is an upper horizontal well clustered fracturing section, 10 is a lower horizontal well clustered fracturing section, 11 is an upper horizontal well clustered fracturing section adjacent spacing, 12 is a lower horizontal well clustered fracturing section adjacent spacing, 13 is a distance of an upper horizontal well and primary coal-structural coal interface, 14 is a distance of a lower horizontal well and structural coal-floor stratum interface, 15 is an upper horizontal well vertical shaft section, 16 is a lower horizontal well vertical shaft section, 17 is a lower horizontal well casing, 18 is a lower horizontal well cement ring, 20 is a lower horizontal well perforation hole, 21 is an upper horizontal well casing, 22 is an upper horizontal well cement ring, and 24 is an upper horizontal well perforation hole.
Detailed Description
The technical scheme of the invention is further described in detail below with reference to the attached drawings and specific embodiments. It is to be understood that the following examples are illustrative only and are not to be construed as limiting the scope of the invention. All techniques implemented based on the above description of the invention are intended to be included within the scope of the invention.
The composite coal seam in the present invention is a coal seam between the overburden 1 and the underburden 4, and is composed of an upper primary coal seam 2 and a lower structural coal seam 3. The underburden layer 4 in the present invention refers to the floor layer.
The method comprises the steps of respectively carrying out well drilling, casing running and fixing on a lower stratum 4 of an upper primary coal bed 2 and a lower structural coal bed 3 to obtain an upper horizontal well 5 and a lower horizontal well 6, wherein the well drilling directions of the upper horizontal well 5 and the lower horizontal well 6 are opposite; the upper horizontal well 5 and the lower horizontal well 6 are fixed by cement after casing, and an upper horizontal well cement sheath 22 and a lower horizontal well cement sheath 18 are formed.
Performing cluster fracturing stage and each cluster fracturing stage perforation operation on the upper horizontal well 5 and the lower horizontal well 6, wherein the upper horizontal well cluster fracturing stage 9 and the lower horizontal well cluster fracturing stage 10 are staggered; the upper horizontal well 5 is located right above the lower horizontal well 6, the lengths are the same, the drilling direction is opposite to the direction of the lower horizontal well 6, and the upper horizontal well clustering fracturing segments 9 and the lower horizontal well clustering fracturing segments 10 are arranged in a staggered mode.
Performing clustered fracturing construction on the lower horizontal well 6, and performing pressure relief and reverse drainage of fracturing fluid through the vertical shaft section 16 of the lower horizontal well after the construction is finished so as to realize sufficient pressure relief on the underlying stratum 4 and the structural coal seam 3; because the underlying stratum 4 is a non-coal bed, the integrity is good, the strength is high, the fluid loss is small, and the displacement is lower than that of the upper horizontal well 5. The pressure relief and the reverse discharge of the fracturing fluid are carried out for a period of time after the well fracturing construction is finished, so that the pressure relief of the underlying stratum 4 and the structural coal seam 3 is realized, a pressure relief disturbance area with a certain range is formed at the lower part of the primary structural coal seam, and the permeability improvement and the gas desorption seepage of the reservoir in the area of the structural coal seam 3 can be promoted.
Performing clustered fracturing construction on the upper horizontal well 5, and performing pressure relief and reverse drainage of fracturing fluid through the vertical shaft section 15 of the upper horizontal well after the construction is finished so as to realize pressure relief of the primary coal seam 2; after the fracturing construction is finished, the pressure relief and the reverse discharge of the fracturing fluid can be implemented on the upper horizontal well 5 for a period of time, so that the pressure relief of the primary coal bed 2 is realized, and the purposes of promoting the desorption of the gas of the primary coal bed 2 and improving the exploitation efficiency of the coal bed gas are achieved.
Gas is produced by the upper horizontal well 5, and water is discharged by the lower horizontal well 6. After the upper horizontal well 5 and the lower horizontal well 6 are constructed, a drainage operation mode of draining water of the upper horizontal well 5 and the lower horizontal well 6 can be considered. Because the density of the gas is small, the gas is moved to the upper part, and the gas collection function of the upper horizontal well 5 can be fully utilized; because the density of water is high, the water mainly seeps downwards, and the water draining function of the lower horizontal well 6 can be fully utilized. The operation can realize the comprehensive aims of relieving pressure, increasing permeability and improving the drainage efficiency of the composite coal seam of the primary structural coal-structural coal by using the double-layer horizontal well.
According to the invention, the upper horizontal well 5 in the upper primary coal bed 2 and the lower horizontal well 6 in the lower stratum 4 are arranged in parallel and opposite, and the two-layer horizontal well is subjected to split fracturing construction for multiple times, so that the fracturing transformation and gas exploitation of the upper primary coal bed 2 and the lower structural coal bed 3 are realized. Before the primary structure coal is fractured, the lower horizontal well 6 is firstly subjected to clustered fracturing, a pressure relief area for stress relief is created, the fracturing and desorption of the coal bed are facilitated, and meanwhile, the pressure relief of the lower part of the constructed coal bed is facilitated, so that the desorption of gas in the coal bed and the migration into cracks of the primary coal bed are facilitated.
In one embodiment, the well bore of the upper horizontal well 5 is positioned in the middle of the primary coal seam.
Preferably, the upper horizontal well 5 is disposed a distance of 0.8 to 1.2m above the raw coal-to-formation coal interface 7.
In a specific embodiment, the upper horizontal well 5 is parallel to the primary coal-formation coal interface 7, and the upper horizontal well 5 is parallel to the syncline axis of the syncline basin when the syncline basin is being constructed.
In order to select a suitable length of the upper horizontal well 5, the length of the upper horizontal well 5 is generally determined comprehensively by combining the flatness of the coal seam, the local structural characteristics, the construction conditions of the ground, and the like, and the length of the upper horizontal well 5 is generally 500-5000 m, and in general, the length of the upper horizontal well 5 is proportional to the thickness of the coal seam, that is, when the coal seam is thicker, the longer the length of the upper horizontal well 5, and when the coal seam is thinner, the shorter the length of the upper horizontal well 5. The length of the lower horizontal well 6 is equal to the length of the upper horizontal well 5 and is 500-5000 m.
Preferably, the lower horizontal well 6 is positioned a distance of 0.8 to 1.2m above the formation coal-floor formation interface 8.
In one embodiment, the lower horizontal well 6 is parallel to the formation coal-floor interface 8, and the lower horizontal well 6 is parallel to the syncline axis of the syncline basin when the syncline basin is being constructed.
In order to ensure that the coal seam volume is matched with the transformation degree, the distance between the clustered fracturing sections of the two adjacent upper horizontal wells 5 is 10-15 m, and the distance between the clustered fracturing sections of the two adjacent upper horizontal wells 5 is inversely proportional to the thickness of the primary coal seam, namely, the clustered distance can take a high value when the thickness of the primary coal seam 2 is smaller, and the clustered distance takes a low value when the thickness of the coal seam is larger.
The perforation of each clustered fracturing stage of the upper horizontal well 5 adopts directional perforation, and the included angle between the perforation of each clustered fracturing stage of the upper horizontal well 5 and the surface of the primary coal seam 2 is less than or equal to +/-30 degrees. The parallel coal seam surface perforation is mainly used, and the perforation is distributed on two sides of the shaft.
The distance between the clustered fracturing sections of two adjacent lower horizontal wells 6 is 10-20 m, and the distance between the clustered fracturing sections of two adjacent lower horizontal wells 6 is inversely proportional to the thickness of the formation coal seam 3.
The directional perforation is adopted for each clustered fracturing stage perforation of the lower horizontal well 6, and each clustered fracturing stage perforation of the lower horizontal well 6 is uniformly arranged at the upper part of the lower horizontal well 6 so as to realize the fracturing transformation of the rock stratum at the upper part of the parallel surface of the horizontal well and the coal bed as a main part, and the perforation is uniformly distributed.
In one embodiment, quartz sand is used as a proppant in clustered fracturing the lower horizontal well 6 in the upper horizontal well 5, and an activated water fracturing fluid is used. The fracturing fluid is a pad fluid-sand carrying fluid-displacement fluid combined fracturing fluid.
In another embodiment, the propping agent is a combination of quartz sand and ceramsite, wherein the mass ratio of the quartz sand to the ceramsite is 3.8-4.2.
The foregoing embodiment numbers of the present invention are merely for the purpose of description, and do not represent the advantages or disadvantages of the embodiments.
The embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to the above-described embodiments, which are merely illustrative and not restrictive, and many forms may be made by those having ordinary skill in the art without departing from the spirit of the present invention and the scope of the claims, which are to be protected by the present invention.
Claims (7)
1. The method for splitting and mining the raw coal and structural coal by using the composite coal bed gas pressure is characterized by comprising the following steps of: drilling, casing and fixing the horizontal well on the lower stratum of the upper primary coal seam and the lower structural coal seam respectively to obtain an upper horizontal well and a lower horizontal well, wherein the drilling directions of the upper horizontal well and the lower horizontal well are opposite; the upper horizontal well is parallel to the primary coal-structural coal interface, or to the syncline axis of the syncline basin, and the lower horizontal well is parallel to the structural coal-floor formation interface, or to the syncline axis of the syncline basin;
performing cluster fracturing sections and perforation operations of each cluster fracturing section on the upper horizontal well and the lower horizontal well, wherein the cluster fracturing sections of the upper horizontal well and the cluster fracturing sections of the lower horizontal well are staggered;
performing clustered fracturing construction on the lower horizontal well, and performing pressure relief and reverse drainage of fracturing fluid through a shaft after the construction is finished so as to realize sufficient pressure relief on an underlying stratum and a structural coal bed;
performing clustered fracturing construction on the upper horizontal well, and performing pressure relief and reverse drainage of fracturing fluid through a shaft after construction so as to realize pressure relief of the primary coal seam;
the perforation of each clustered fracturing section of the upper horizontal well adopts directional perforation, the included angle between the perforation of each clustered fracturing section of the upper horizontal well and the primary coal seam layer is less than or equal to +/-30 degrees, and the perforation is mainly parallel to the coal seam layer, and is distributed on two sides of a shaft; the lower horizontal well is provided with a plurality of clustered fracturing stage perforations, and each clustered fracturing stage perforation of the lower horizontal well is uniformly arranged at the upper part of the lower horizontal well so as to realize the fracturing transformation of the rock stratum at the upper part of the parallel surface of the horizontal well and the coal seam;
and (3) utilizing the upper horizontal well to produce gas and utilizing the lower horizontal well to drain water.
2. The method for splitting and mining the raw coal and structural coal composite coal bed gas pressure according to claim 1, which is characterized in that: the well hole of the upper horizontal well is arranged on the upper side of the middle part of the primary coal seam.
3. The method for splitting and mining the raw coal and structural coal composite coal bed gas pressure according to claim 2, which is characterized in that: the upper horizontal well is disposed a distance of 0.8-1.2 m above the primary coal-structural coal interface.
4. The method for splitting and mining the raw coal and structural coal composite coal bed gas pressure according to claim 1, which is characterized in that: the length of the upper horizontal well is 500-5000 m, and the length of the upper horizontal well is proportional to the thickness of the coal seam.
5. The method for splitting and mining the raw coal and structural coal composite coal bed gas pressure according to claim 1, which is characterized in that: the lower horizontal well is disposed a distance of 0.8-1.2 m above the formation coal-floor formation interface.
6. The method for splitting and mining the raw coal and structural coal composite coal bed gas pressure according to claim 1, which is characterized in that: the distance between the clustered fracturing sections of two adjacent upper horizontal wells is 10-15 m, and the distance between the clustered fracturing sections of two adjacent upper horizontal wells is inversely proportional to the thickness of the primary coal seam.
7. The method for splitting and mining the raw coal and structural coal composite coal bed gas pressure according to claim 1, which is characterized in that: the distance between the clustered fracturing sections of two adjacent lower horizontal wells is 10-20 m, and the distance between the clustered fracturing sections of two adjacent lower horizontal wells is inversely proportional to the thickness of the constructed coal seam.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210368863.9A CN114704227B (en) | 2022-04-08 | 2022-04-08 | Method for splitting and mining raw coal and structural coal by using composite coal bed gas pressure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210368863.9A CN114704227B (en) | 2022-04-08 | 2022-04-08 | Method for splitting and mining raw coal and structural coal by using composite coal bed gas pressure |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114704227A CN114704227A (en) | 2022-07-05 |
| CN114704227B true CN114704227B (en) | 2023-08-11 |
Family
ID=82172131
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210368863.9A Active CN114704227B (en) | 2022-04-08 | 2022-04-08 | Method for splitting and mining raw coal and structural coal by using composite coal bed gas pressure |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114704227B (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2256079C1 (en) * | 2004-04-05 | 2005-07-10 | Государственное образовательное учреждение высшего профессионального образования Санкт-Петербургский государственный горный институт им. Г.В. Плеханова (технический университет) | Method for extracting methane from coal bed |
| CN111520119A (en) * | 2020-04-28 | 2020-08-11 | 中煤科工集团西安研究院有限公司 | Method for efficiently extracting coal bed gas by staged fracturing of large-spacing thin coal seam group multi-bottom horizontal well |
| CN112593936A (en) * | 2020-11-27 | 2021-04-02 | 陕西彬长孟村矿业有限公司 | Advanced comprehensive prevention and control method for multiple disaster areas of deep mine |
| CN112855087A (en) * | 2021-03-22 | 2021-05-28 | 河北佐和佑石油技术发展有限公司 | Coal bed gas horizontal well system transformation method |
| CN113356824A (en) * | 2021-07-01 | 2021-09-07 | 山西蓝焰煤层气工程研究有限责任公司 | Integral development method for adjacent coal seam horizontal well in multi-coal seam development area |
| CN113605874A (en) * | 2021-08-10 | 2021-11-05 | 山西蓝焰煤层气集团有限责任公司 | Method for extracting coal bed gas of broken soft coal bed top and bottom double-layer horizontal well |
-
2022
- 2022-04-08 CN CN202210368863.9A patent/CN114704227B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2256079C1 (en) * | 2004-04-05 | 2005-07-10 | Государственное образовательное учреждение высшего профессионального образования Санкт-Петербургский государственный горный институт им. Г.В. Плеханова (технический университет) | Method for extracting methane from coal bed |
| CN111520119A (en) * | 2020-04-28 | 2020-08-11 | 中煤科工集团西安研究院有限公司 | Method for efficiently extracting coal bed gas by staged fracturing of large-spacing thin coal seam group multi-bottom horizontal well |
| CN112593936A (en) * | 2020-11-27 | 2021-04-02 | 陕西彬长孟村矿业有限公司 | Advanced comprehensive prevention and control method for multiple disaster areas of deep mine |
| CN112855087A (en) * | 2021-03-22 | 2021-05-28 | 河北佐和佑石油技术发展有限公司 | Coal bed gas horizontal well system transformation method |
| CN113356824A (en) * | 2021-07-01 | 2021-09-07 | 山西蓝焰煤层气工程研究有限责任公司 | Integral development method for adjacent coal seam horizontal well in multi-coal seam development area |
| CN113605874A (en) * | 2021-08-10 | 2021-11-05 | 山西蓝焰煤层气集团有限责任公司 | Method for extracting coal bed gas of broken soft coal bed top and bottom double-layer horizontal well |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114704227A (en) | 2022-07-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111520119B (en) | Method for efficiently extracting coal bed gas by staged fracturing of large-spacing thin coal seam group multi-bottom horizontal well | |
| Jiang et al. | Volume fracturing of deep shale gas horizontal wells | |
| CN108561106B (en) | Oil and gas exploitation method for increasing recovery ratio by controlling reserves through artificial seams | |
| CN102080526B (en) | Method for extracting gas from bedding level fractured well of ground coal seam roof | |
| CN101818620B (en) | Mining method for maximum reservoir contact well | |
| CN102392677A (en) | Permeability improvement technology for coal bed gas reservoir cap by using three-dimensional fracture network modification | |
| Bi et al. | Geological characteristics and co-exploration and co-production methods of Upper Permian Longtan coal measure gas in Yangmeishu Syncline, Western Guizhou Province, China | |
| CN104100244A (en) | Well spacing method for coal bed gas communication well groups and application of well spacing method in fracturing yield increase | |
| CN106437642A (en) | Injection-production asynchronous mining method for horizontal well of fractured reservoir | |
| CN113738335B (en) | Fracture control integrated volume fracturing method suitable for massive pure shale oil reservoir | |
| CN104895531A (en) | Single thick coal seam ground mining well extraction process | |
| CN110306965A (en) | A kind of method for increasing for coal bed gas low yield wellblock | |
| CN105822284A (en) | Triangular horizontal well pattern well spacing method | |
| CN110552673A (en) | Method for improving extraction degree of low-pressure tight oil reservoir | |
| CN107620581A (en) | The construction method of the dual-purpose mine shaft inspection hole of one well | |
| CN103485773A (en) | Method for determining multi-branch horizontal well branch parameters | |
| CN114704227B (en) | Method for splitting and mining raw coal and structural coal by using composite coal bed gas pressure | |
| RU2528757C1 (en) | Development of low-permeability oil deposits by horizontal wells under natural conditions | |
| CN103362487A (en) | Staged fracturing method for low-permeability reservoir horizontal well | |
| CN109209327B (en) | Active drainage gas production method for high-water-yield coal bed gas well group of communication fault | |
| CN204729127U (en) | Sand control pack device | |
| CN205936571U (en) | Raising output is transformed and novel coal seam gas well of formation to old well | |
| CN205936553U (en) | Raising output is transformed and novel coal seam gas well of formation to old well | |
| CN115126506A (en) | Grouting transformation method for protecting coal pillar of fourth aquifer of liberation shallow part | |
| CN112324413B (en) | Chemical construction method for improving injection amount of injection well |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |