CN110185418B - Coal bed gas mining method for coal bed group - Google Patents
Coal bed gas mining method for coal bed group Download PDFInfo
- Publication number
- CN110185418B CN110185418B CN201910536892.XA CN201910536892A CN110185418B CN 110185418 B CN110185418 B CN 110185418B CN 201910536892 A CN201910536892 A CN 201910536892A CN 110185418 B CN110185418 B CN 110185418B
- Authority
- CN
- China
- Prior art keywords
- coal seam
- coal bed
- coal
- horizontal well
- 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
Images
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP 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 DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP 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. optimizing the spacing of wells
- E21B43/305—Specific pattern of wells, e.g. optimizing the spacing of wells comprising at least one inclined or horizontal well
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B7/00—Special methods or apparatus for drilling
- E21B7/20—Driving or forcing casings or pipes into boreholes, e.g. sinking; Simultaneously drilling and casing boreholes
Abstract
The invention discloses a coal bed gas mining method of coal bed groups, wherein each coal bed group is drilled with a horizontal well, so that each coal bed group can have a sufficiently large contact area with a shaft, the horizontal wells of the coal bed groups at two adjacent positions are communicated through drilled branch well bores, the communication of the horizontal wells of a plurality of coal bed groups is realized, the combined mining of the plurality of coal bed groups is realized during drainage and mining, the plurality of coal bed groups exert a synergistic depressurization effect, a pressure drop funnel of the adjacent coal bed groups is formed, the leakage rate of a reservoir is effectively improved, the reservoir productivity is increased to the maximum extent, all the coal bed groups with high coal bed gas content in a coal-bearing stratum are considered in the combined mining process, and the coal bed gas productivity of the coal bed groups is effectively improved.
Description
Technical Field
The invention relates to the technical field of coal bed methane mining, in particular to a coal bed methane mining method for a coal bed group.
Background
The coal deposit environment in some regions is influenced by sea invasion, coal seam groups with multiple layers, small thickness and discontinuous distribution are formed, and coal bed gas systems among different coal seam groups are relatively independent, but the coal seam groups are longitudinally distributed in the whole section.
The development characteristics of the thickness and the interval of the coal seam are inspected, the coal seam group is reasonably divided into sections, the defects of partial thinness, resource dispersion and the like of a single coal seam group can be overcome, the resource advantages are convenient to concentrate, a reasonable reservoir transformation scheme is formulated, and the productivity of the coal seam gas is improved.
The most common coal bed gas development methods mainly comprise two types, namely underground gas drainage and surface well drilling exploitation.
The underground coal bed gas pumping and discharging is to drill holes in a coal mine underground mining roadway, and the coal bed gas in the coal bed is pumped on the ground through a coal bed gas pump.
The coal bed gas mined by the ground well drilling enters an unexplored coal bed from the ground well drilling, the coal bed gas in the coal bed is desorbed by draining and depressurizing, and then flows to the ground through the shaft. However, one well can only consider developing a plurality of adjacent coal seam groups, and cannot consider all the coal seam groups with high coal seam gas content in the coal-bearing stratum at the same time, so that the coal seam gas productivity of the coal seam groups is influenced.
Therefore, how to improve the coal bed methane productivity of the coal bed group becomes a technical problem to be solved urgently by the technical personnel in the field.
Disclosure of Invention
In view of this, the present invention provides a method for exploiting coal bed methane of a coal bed group to improve the coal bed methane productivity of the coal bed group.
In order to achieve the purpose, the invention provides the following technical scheme:
a coal bed methane mining method for a coal bed group comprises the following steps:
step 1) drilling a plurality of horizontal wells, wherein the horizontal wells sequentially drill coal seam groups at adjacent positions from low to high;
step 2) drilling a branch well hole of a horizontal well for communicating the coal seam groups at two adjacent positions;
and 3) installing drainage and mining equipment on the horizontal well of the coal seam group at the lowest drilling position.
Preferably, in the method for exploiting coal bed methane of the coal bed group, between the step 1) and the step 2), further comprising:
step 11) running a technical casing in the horizontal well;
and 12) putting a production casing under the horizontal well, wherein the production casing is hung at the lower end of the technical casing.
Preferably, in the method for exploiting coal bed methane in the coal seam group, in the step 12), the length of the production casing entering the horizontal well of the coal seam group at the lowest position is 10-15 m.
Preferably, in the method for extracting coal bed methane from the coal seam group, in the step 12), the upper end of the production casing of the horizontal well of the coal seam group located above the lowest position of the coal seam group is spaced from the bottom of the technical casing by 40 to 60 m.
Preferably, in the method for exploiting coal bed methane of the coal bed group, the step 2) includes:
step 21) drilling a lateral borehole with the depth of 30m at the bottom of the technical casing of the horizontal well of the coal seam group above the coal seam group at the lowest position, wherein the lateral borehole is communicated with the horizontal section of the horizontal well of the coal seam group at the lowest position or is communicated with the horizontal section of the horizontal well of the coal seam group at the adjacent position with the lower height.
Preferably, in the method for extracting coal bed gas from the coal bed group, the well angle of the branch well bore is 80 ± 2 °.
Preferably, in the method for exploiting coal bed methane of the coal bed group, the step 2) further includes:
step 22) located after step 21): and (3) running a branch well production casing in the branch well, wherein the branch well production casing is hung at the lower end of the technical casing corresponding to the horizontal well.
Preferably, in the method for extracting coal bed gas from the coal seam group, in the step 22), the length of the branch well production casing entering the technical casing is 10-15 m.
Preferably, in the method for extracting coal bed gas from the coal bed group, the spacing between the adjacent coal bed groups is 50-100m, and the reservoir thickness is more than 2.5 m.
Preferably, in the method for exploiting coal bed methane of the coal bed group, the horizontal section of the horizontal well is drilled in an upward-inclined direction.
According to the technical scheme, each coal bed group is drilled with one horizontal well, so that each coal bed group can have a large enough contact area with a shaft, the horizontal wells of the two adjacent coal bed groups are communicated through the drilled branch well holes, the communication of the horizontal wells of the multiple coal bed groups is realized, the combined mining of the multiple coal bed groups is realized during drainage and mining, the multiple coal bed groups exert a synergistic depressurization effect, a pressure drop funnel of the adjacent coal bed groups is formed, the leakage rate of a reservoir is effectively improved, the productivity of the reservoir is increased to the maximum extent, all the coal bed groups with high coal bed gas content in a coal-bearing stratum are considered in the combined mining process, and the productivity of the coal bed groups is effectively improved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a three-dimensional projection view of a horizontal well provided by an embodiment of the invention;
FIG. 2 is a flow chart of a method for producing coalbed methane from a coal seam group according to a first embodiment of the present invention;
FIG. 3 is a flow chart of a method for producing coalbed methane from a coal seam group according to a second embodiment of the present invention;
FIG. 4 is a flow chart of a method for producing coalbed methane from a coalbed methane group according to a third embodiment of the present invention;
fig. 5 is a flowchart of a coalbed methane mining method for a coalbed methane group according to a fourth embodiment of the invention.
1. A first horizontal well, 2, a second horizontal well, 3, a branch wellbore.
Detailed Description
The invention discloses a coal bed methane mining method of a coal bed group, which aims to improve the coal bed methane productivity of the coal bed group.
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The invention discloses a coal bed methane mining method of a coal bed group, which comprises the following steps:
step 1) drilling a plurality of horizontal wells, wherein the horizontal wells sequentially drill coal seam groups at adjacent positions from low to high;
step 2), drilling a branch well hole of a horizontal well for communicating two adjacent coal seam groups;
and 3) installing drainage and mining equipment on a horizontal well drilled with the coal seam group at the lowest position.
In the step 1), drilling a horizontal section of the horizontal well along an upward inclining direction. Specifically, each coal seam group is drilled with a horizontal well, and each coal seam group can be effectively exploited, so that all coal seam groups with high coal bed gas content in the coal-bearing stratum can be considered simultaneously;
in the step 2), an upper horizontal well and a lower horizontal well need to be communicated, and only one branch well is arranged between the two adjacent horizontal wells;
and 3) arranging and mining equipment on the horizontal well of the coal seam group at the lowest drilling position to realize simultaneous drainage and mining of multiple horizontal wells.
According to the coal bed gas mining method for the coal bed groups, each coal bed group is mined by the horizontal well, the contact area between the horizontal well and the reservoir is ensured, reservoir cracks are communicated, and the method is the most effective coal bed gas mining method.
According to the coal bed gas mining method for the coal bed group, the branch well is drilled between the horizontal wells of the two adjacent coal bed groups, the branch well can be communicated with the horizontal wells of the two adjacent coal bed groups, coal bed gas co-mining of the adjacent coal bed groups is achieved, and the mining efficiency of the coal bed groups is improved on the basis of reducing the drainage and mining cost.
According to the coal bed gas mining method for the coal bed groups, each coal bed group is drilled with one horizontal well, so that each coal bed group can have a large enough contact area with a shaft, the horizontal wells of the coal bed groups at two adjacent positions are communicated through the drilled branch well, the communication of the horizontal wells of the coal bed groups is realized, the combined mining of the coal bed groups is realized during drainage and mining, the coal bed groups exert a synergistic depressurization effect, pressure drop funnels of the adjacent coal bed groups are formed, the leakage rate of a reservoir is effectively improved, the reservoir productivity is increased to the maximum extent, all the coal bed groups with high coal bed gas content in a coal-bearing stratum are considered in the combined mining process, and the coal bed gas productivity of the coal bed groups is effectively improved.
As shown in the figure, an embodiment for forming two horizontal wells is disclosed, and in actual drainage and production, drainage and production equipment is put into a first horizontal well 1, reservoir water and coal bed gas in a second horizontal well 2 enter the first horizontal well 1 through a branch well 3 and are lifted to the ground through the first horizontal well 1.
The first horizontal well 1 and the second horizontal well 2 are simultaneously drained and mined, a synergistic depressurization effect is exerted, a pressure drop funnel of adjacent coal seam groups is formed, the leakage rate of a reservoir is effectively improved, and the reservoir productivity is increased to the greatest extent.
In order to further optimize the above technical solution, the method further includes, between step 1) and step 2):
step 11) putting a technical casing in the horizontal well;
and step 12) putting a production casing under the horizontal well, wherein the production casing is hung at the lower end of the technical casing.
Specifically, the length of a production casing entering a technical casing of the horizontal well drilling the coal seam group at the lowest position in the step 12) is 10-15 m;
in the step 12), the upper end of a production casing of a horizontal well of the coal seam group above the lowest position coal seam group is 40-60m away from the bottom of the technical casing. The embodiment lays a foundation for the opening of the branch well bore.
In a specific embodiment of the present solution, step 2) includes:
and 21) sidetracking a branch borehole with the depth of 30m at the bottom of the technical casing of the horizontal well of the coal seam group positioned above the coal seam group at the lowest position, wherein the branch borehole is communicated with the horizontal section of the horizontal well of the coal seam group at the lowest position or is communicated with the horizontal section of the horizontal well of the coal seam group at the adjacent position and with the lower height.
And the branch well hole is arranged on a horizontal well of the coal seam group with the higher position of the two adjacent coal seam groups.
A branch well hole drilled on the horizontal well of the coal seam group adjacent to the coal seam group at the lowest position is communicated with the horizontal section of the horizontal well of the coal seam group at the lowest position; and branch well holes drilled on the horizontal wells of the coal seam groups adjacent to the coal seam group at the non-lowest position are communicated with the horizontal sections of the horizontal wells of the coal seam groups at the adjacent positions and with lower heights.
Specifically, the offset angle of the lateral borehole is 80 ± 2 °.
Step 2) also includes:
step 22) located after step 21): and (3) running a branch well production casing in the branch well, and suspending the branch well production casing at the lower end of the technical casing corresponding to the horizontal well.
Specifically, in step 22), the length of the branch well production casing into the technical casing is 10-15 m.
The coal bed methane mining method for the coal bed groups is suitable for reservoirs with the spacing of the coal bed groups at the adjacent positions being 50-100m and the thickness of the reservoir being more than 2.5 m.
In the actual drilling process of the horizontal well, a horizontal section of the horizontal well is drilled along the upward inclining direction.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (10)
1. A coal bed gas mining method for a coal bed group is characterized by comprising the following steps:
step 1) drilling a plurality of horizontal wells, wherein the horizontal wells sequentially drill coal seam groups at adjacent positions from low to high;
step 2) drilling a branch well of a horizontal well for communicating two adjacent coal seam groups, wherein the branch well is arranged on a horizontal well of a coal seam group with a higher position of two adjacent coal seam groups, the branch well is communicated with an upper horizontal well and a lower horizontal well, only one branch well is arranged between the two adjacent horizontal wells, the communication of the horizontal wells of the multiple coal seam groups is realized, the combined mining of the multiple coal seam groups is realized during drainage and mining, the multiple coal seam groups exert a synergistic pressure reduction effect to form a pressure reduction funnel of the adjacent coal seam groups, during actual drainage and mining, drainage and mining equipment is put into a first horizontal well (1), reservoir water and coal bed gas in a second horizontal well (2) enter the first horizontal well (1) through the branch well (3) and are lifted to the ground through the first horizontal well (1), and the first horizontal well (1) is the horizontal well of the coal seam group with the lowest position, the second horizontal well (2) is a horizontal well above the height of the first horizontal well (1), and the number of the second horizontal wells (2) is at least one;
and 3) installing drainage and mining equipment on the horizontal well of the coal seam group at the lowest drilling position.
2. The method for exploiting coal bed methane of the coal bed group according to claim 1, wherein the step 1) and the step 2) further comprise:
step 11) running a technical casing in the horizontal well;
and 12) putting a production casing under the horizontal well, wherein the production casing is hung at the lower end of the technical casing.
3. A method for exploiting coal seam gas of a coal seam group according to claim 2, characterized in that in the step 12), the length of the production casing entering the horizontal well of the coal seam group at the lowest position into the technical casing is 10-15 m.
4. A method for exploiting coal seam gas of a coal seam group according to claim 2, characterized in that in step 12), the upper end of the production casing of the horizontal well of the coal seam group located above the lowest position of the coal seam group is 40-60m away from the bottom of the technical casing.
5. The method for exploiting coal bed methane of the coal bed group according to claim 1, wherein the step 2) comprises:
step 21) drilling a lateral borehole with the depth of 30m at the bottom of the technical casing of the horizontal well of the coal seam group above the coal seam group at the lowest position, wherein the lateral borehole is communicated with the horizontal section of the horizontal well of the coal seam group at the lowest position or is communicated with the horizontal section of the horizontal well of the coal seam group at the adjacent position with the lower height.
6. The method of mining coal seam gas of a coal seam group according to claim 5, wherein the angle of inclination of the branch well bore is 80 ± 2 °.
7. The method for exploiting coal bed methane of the coal seam group according to claim 5, wherein the step 2) further comprises:
step 22) located after step 21): and (3) running a branch well production casing in the branch well, wherein the branch well production casing is hung at the lower end of the technical casing corresponding to the horizontal well.
8. The method of mining coal seam gas in a coal seam group according to claim 7, wherein in the step 22), the length of the branch wellbore production casing into the technical casing is 10-15 m.
9. The method of mining coal bed methane of a coal seam group as claimed in claim 1, wherein the spacing between adjacent coal seam groups is 50-100m, and the reservoir thickness is greater than 2.5 m.
10. The method for exploiting coal bed methane of the coal bed group according to claim 1, wherein the horizontal section of the horizontal well is drilled in an upward-inclined direction.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910536892.XA CN110185418B (en) | 2019-06-20 | 2019-06-20 | Coal bed gas mining method for coal bed group |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910536892.XA CN110185418B (en) | 2019-06-20 | 2019-06-20 | Coal bed gas mining method for coal bed group |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110185418A CN110185418A (en) | 2019-08-30 |
| CN110185418B true CN110185418B (en) | 2022-04-19 |
Family
ID=67722573
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910536892.XA Active CN110185418B (en) | 2019-06-20 | 2019-06-20 | Coal bed gas mining method for coal bed group |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110185418B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111980643A (en) * | 2020-09-01 | 2020-11-24 | 中联煤层气有限责任公司 | Coal bed gas horizontal well construction method and coal bed gas horizontal well |
| 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 |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6280000B1 (en) * | 1998-11-20 | 2001-08-28 | Joseph A. Zupanick | Method for production of gas from a coal seam using intersecting well bores |
| US8333245B2 (en) * | 2002-09-17 | 2012-12-18 | Vitruvian Exploration, Llc | Accelerated production of gas from a subterranean zone |
| CN102116140B (en) * | 2011-01-25 | 2012-01-18 | 煤炭科学研究总院西安研究院 | Construction method for enhancing extraction effect of ground coal bed gas |
| CN102852490A (en) * | 2012-09-07 | 2013-01-02 | 北京九尊能源技术股份有限公司 | High gas suction and discharge process method for complex well |
| CN203335054U (en) * | 2013-05-31 | 2013-12-11 | 华北石油管理局 | Multi-branch horizontal well system suitable for coalbed methane of syncline structure |
| CA2820742A1 (en) * | 2013-07-04 | 2013-09-20 | IOR Canada Ltd. | Improved hydrocarbon recovery process exploiting multiple induced fractures |
| CN104196453B (en) * | 2014-08-29 | 2017-02-15 | 富地柳林燃气有限公司 | Coalbed methane development well |
| CN104358555A (en) * | 2014-10-30 | 2015-02-18 | 北京奥瑞安能源技术开发有限公司 | Multi-branch lateral well system and construction method thereof |
| CN109577919B (en) * | 2017-09-28 | 2020-06-09 | 中国石油天然气股份有限公司 | Mining method of coal bed gas in low-permeability coal bed |
| CN108643960A (en) * | 2018-05-21 | 2018-10-12 | 河南工程学院 | A kind of ground region band coal mine gas extinction technique |
-
2019
- 2019-06-20 CN CN201910536892.XA patent/CN110185418B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN110185418A (en) | 2019-08-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101915083B (en) | Method for extracting coalbed gases from coal mines by upper and lower combination | |
| CN111520119B (en) | Method for efficiently extracting coal bed gas by staged fracturing of large-spacing thin coal seam group multi-bottom horizontal well | |
| CN102080526B (en) | Method for extracting gas from bedding level fractured well of ground coal seam roof | |
| US6591903B2 (en) | Method of recovery of hydrocarbons from low pressure formations | |
| CN104806217B (en) | Combined separated layer fracturing, grouping and layer-combining mining method for coal bed well group | |
| US10030491B2 (en) | Method for increasing gas recovery in fractures proximate fracture treated wellbores | |
| CN113738317A (en) | Method for combined exploitation of deep coal bed gas and dry hot rock type geothermal | |
| CN110185418B (en) | Coal bed gas mining method for coal bed group | |
| CN102852490A (en) | High gas suction and discharge process method for complex well | |
| CN101915084B (en) | Process for pumping and exploiting coal bed gas by using ground well drilling and underground hole drilling | |
| RU2485291C1 (en) | Development method of productive formation with low-permeability section | |
| CN110552673A (en) | Method for improving extraction degree of low-pressure tight oil reservoir | |
| CN109057757B (en) | Natural gas hydrate exploitation method and device | |
| RU2474678C1 (en) | Development method of oil deposit with horizontal wells | |
| CN111058891B (en) | Method for replacing and extracting coal seam gas in underground and aboveground modes | |
| RU2425211C1 (en) | Combined method of thermal well development of high-viscous oil deposit | |
| CN109209327B (en) | Active drainage gas production method for high-water-yield coal bed gas well group of communication fault | |
| CN209892171U (en) | Horizontal well section staggered displacement and imbibition displacement injection-production string | |
| CN110593846A (en) | Gas well gas-liquid separate production well completion pipe string | |
| RU2531074C2 (en) | Method for arrangement of vertical and lateral flooding | |
| CN213478312U (en) | Thick coal seam vertical well modified horizontal well drainage and production structure | |
| CN109899106B (en) | Gas extraction method for adjacent layer of turning long drill hole for avoiding caving zone | |
| CN109577941B (en) | Coal bed gas drilling and mining method | |
| RU2616016C9 (en) | Recovery method for solid carbonate reservoirs | |
| CN112392452A (en) | Method for inducing fracturing by fixed-face perforation of horizontal well of thin interbed reservoir |
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 |