CN113585973A - Construction method of fishbone horizontal well of coal bed gas and coal bed gas mining method - Google Patents
Construction method of fishbone horizontal well of coal bed gas and coal bed gas mining method Download PDFInfo
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- 238000000034 method Methods 0.000 title claims abstract description 35
- 238000010276 construction Methods 0.000 title claims abstract description 31
- 238000005065 mining Methods 0.000 title claims abstract description 8
- 238000005553 drilling Methods 0.000 claims abstract description 95
- 230000001681 protective effect Effects 0.000 claims abstract description 29
- 230000035699 permeability Effects 0.000 claims abstract description 24
- 230000008569 process Effects 0.000 claims abstract description 11
- 239000004698 Polyethylene Substances 0.000 claims description 18
- 238000004873 anchoring Methods 0.000 claims description 7
- 230000003287 optical effect Effects 0.000 claims description 7
- 238000005086 pumping Methods 0.000 claims description 5
- 238000005422 blasting Methods 0.000 claims description 4
- 239000004033 plastic Substances 0.000 claims description 4
- 229920003023 plastic Polymers 0.000 claims description 4
- -1 polyethylene Polymers 0.000 claims description 4
- 229920000573 polyethylene Polymers 0.000 claims description 4
- 238000007599 discharging Methods 0.000 claims description 3
- 238000010008 shearing Methods 0.000 claims description 3
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- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 20
- 238000002347 injection Methods 0.000 description 13
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- 230000009286 beneficial effect Effects 0.000 description 4
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- 239000011435 rock Substances 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
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- 239000004576 sand Substances 0.000 description 2
- 238000005488 sandblasting Methods 0.000 description 2
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- 229910000831 Steel Inorganic materials 0.000 description 1
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- 238000005516 engineering process Methods 0.000 description 1
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- 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
- E21B7/00—Special methods or apparatus for drilling
- E21B7/18—Drilling by liquid or gas jets, with or without entrained pellets
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- 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
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- 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
- E21B43/02—Subsoil filtering
- E21B43/08—Screens or liners
- E21B43/086—Screens with preformed openings, e.g. slotted liners
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- 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
- E21B7/00—Special methods or apparatus for drilling
- E21B7/04—Directional drilling
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Abstract
The invention provides a construction method of a fishbone horizontal well for coal bed gas and a coal bed gas mining method, and belongs to the technical field of coal bed gas mining. The coal bed gas fishbone horizontal well comprises a straight well section, an inclined section and a horizontal section which are sequentially connected, wherein the horizontal section comprises a main well hole and a plurality of branch well holes connected to the main well hole, and the construction method comprises the following steps: drilling the straight well section and the deflecting section which are connected in sequence by using a drilling tool; drilling the horizontal section using a drilling tool; in the process of drilling the horizontal section, a main protective pipe with permeability is lowered into a main well bore of the drilled horizontal section, and a plurality of branch protective pipes with permeability are lowered into a plurality of branch well bores of the drilled horizontal section respectively. The method ensures the stability of the main well bore and each branch well bore.
Description
Technical Field
The disclosure relates to the field of coal bed gas exploitation, in particular to a construction method of a fishbone horizontal well of coal bed gas and a coal bed gas exploitation method.
Background
Coal bed gas (commonly called as gas) is another novel and clean energy source following petroleum and natural gas. The multi-branch horizontal well becomes an important means for exploiting coal bed gas resources in China, and the multi-branch horizontal well technology can be applied to greatly increase the coal bed permeation area and improve the gas production rate and the recovery rate of a single well.
The conventional coal bed gas multi-branch horizontal well mainly comprises a straight well section, an inclined section and a horizontal section which are sequentially connected. The horizontal section is provided with a main borehole, the main borehole is connected with a plurality of branch boreholes, and the branch boreholes are distributed on two sides of the main borehole and arranged in a vein mode.
In the related art, the construction method of the coal bed gas multi-branch horizontal well comprises the following steps: and sequentially drilling a straight well section, an inclined section and a horizontal section of the horizontal well, and finally putting a supporting pipe with permeability in the horizontal section of the horizontal well so as to enhance the stability of a supported borehole. However, the method can only ensure the stability of the main well bore of the horizontal section of the horizontal well, but cannot ensure the stability of each branch well bore. Once each branch well hole collapses, great influence can be produced to coal bed gas production.
Disclosure of Invention
The embodiment of the disclosure provides a construction method of a fishbone horizontal well of coal bed gas and a mining method of coal bed gas, and the stability of a main well and each branch well is guaranteed. The technical scheme is as follows:
the embodiment of the disclosure provides a construction method of a coal bed gas fishbone horizontal well, the coal bed gas fishbone horizontal well comprises a straight well section, a deflecting section and a horizontal section which are sequentially connected, the horizontal section comprises a main well bore and a plurality of branch well bores connected to the main well bore, and the construction method comprises the following steps:
drilling the straight well section and the deflecting section which are connected in sequence by using a drilling tool;
drilling the horizontal section using a drilling tool;
in the process of drilling the horizontal section, a main protective pipe with permeability is lowered into a main well bore of the drilled horizontal section, and a plurality of branch protective pipes with permeability are lowered into a plurality of branch well bores of the drilled horizontal section respectively.
Optionally, the drilling the horizontal section with a drilling tool comprises:
dividing the main wellbore into a plurality of sections according to the positions of the plurality of branch wellbores;
drilling sections of the main wellbore and the plurality of lateral wellbores, respectively, using a drilling tool;
in the process of drilling the horizontal section, a main protective pipe with permeability is lowered into a main well bore of the drilled horizontal section, and a plurality of branch protective pipes with permeability are lowered into a plurality of branch well bores of the drilled horizontal section respectively, wherein the process comprises the following steps:
and after each branch well hole is drilled, one branch pipe is put into the corresponding branch well hole, and after a plurality of sections of main well holes are drilled, the main protection pipe is put into the main well hole.
Optionally, said running one of said supporting pipes in a corresponding said lateral wellbore after each drilling of one said lateral wellbore comprises:
each time one branch well hole is drilled, a light drill rod is put into the branch well hole;
injecting the supporting pipe into the optical drill rod for a preset length and then shearing;
and pumping the supporting pipe into the branch well hole through a drill pipe for anchoring, and reserving a set distance between the tail end of the supporting pipe and the deflecting point of the main well hole.
Optionally, the set distance is 30-50 cm.
Optionally, the horizontal section comprises N sections of the main boreholes and N-1 branched boreholes, wherein N is a positive integer greater than 0, and two adjacent sections of the main boreholes are separated by one branched borehole;
the drilling of the sections of the main wellbore and the plurality of lateral wellbores, respectively, using a drilling tool, comprising:
from the 1 st section of the main borehole, repeating the following steps until the drilling tool is taken out after N sections of the main borehole and N-1 branch boreholes are drilled:
drilling a pth branch well hole after drilling the mth section of main well hole;
withdrawing to the terminal of the m section of the main borehole, and continuously drilling the m +1 section of the main borehole according to the extension direction of the main borehole;
the p-th branch well hole is positioned at the terminal of the m-th section of the main well hole, m and p are positive integers larger than 0, m is smaller than or equal to N, p is smaller than or equal to N-1, the terminal of the m-th section of the main well hole is one end far away from the deflecting section, and the 1-st section of the main well hole is one section of the main well hole connected with the deflecting section.
Optionally, after the horizontal section is drilled and the main protection pipe and the supporting pipe are lowered, the construction method further comprises:
and treating the sidetracking points of the plurality of branch well bores by adopting a hydraulic jetting method.
Optionally, the method of treating sidetracking points of the plurality of lateral wellbores with hydrajetting includes:
running a hydrajetting tool into the main wellbore using a fracturing apparatus;
repeating the following steps from the N-1 th branch well hole until the hydrajetting is carried out on the side drilling points of the N-1 branch well holes, and then taking out the hydrajetting tools:
moving the hydrajetting tool to a pth lateral wellbore;
hydraulically blasting at the sidetrack point of the p-th branch well hole to form a cave channel at the sidetrack point of the p-th branch well hole;
returning to the terminal of the main well bore of the (m-1) th section, and hydraulically blasting the sidetrack drilling point of the (p-1) th branch well bore by using the hydraulic jet tool to form a cave channel at the sidetrack drilling point of the (p-1) th branch well bore;
wherein the N-1 th branched well bore is the one of the N-1 branched well bores which is farthest away from the deflecting section.
Optionally, the support tube is a polyethylene plastic screen.
Optionally, the length of the main well bore is 800-1500m, the interval between two adjacent branch well bores is 100-200 m, and the length of each branch well bore is 200-300 m.
In a second aspect, a coal bed gas exploitation method for a fishbone horizontal well of coal bed gas is provided, and the coal bed gas exploitation method comprises the following steps:
and (3) discharging and mining by using a rodless pump in the coal bed gas fishbone horizontal well, wherein the coal bed gas fishbone horizontal well is obtained by construction according to the construction method in the first aspect.
The beneficial effects brought by the technical scheme provided by the embodiment of the disclosure at least comprise:
the drilling tool is used for drilling a straight well section and a deflecting section which are connected in sequence, then a horizontal section is drilled, and when the horizontal section is drilled, a main protective pipe with permeability is put into a main well hole of the drilled horizontal section, and the main protective pipe can ensure the stability of the main well hole of the horizontal section. Simultaneously, a plurality of supporting pipes with permeability are respectively put into a plurality of branch well bores of the drilled horizontal section. The multiple supporting pipes can enhance the stability of multiple branch boreholes, effectively prevent adverse effects caused by collapse and blockage of the branch boreholes, and are beneficial to efficient and safe development of the coal bed gas horizontal well.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present disclosure, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.
Fig. 1 is a schematic structural diagram of a coal bed methane fishbone horizontal well provided by an embodiment of the disclosure;
fig. 2 is a flow chart of a construction method of a coal bed methane fishbone horizontal well provided by the embodiment of the disclosure;
fig. 3 is a flow chart of another construction method of a coal bed methane fishbone horizontal well provided by the embodiment of the disclosure.
Detailed Description
To make the objects, technical solutions and advantages of the present disclosure more apparent, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.
For better understanding of the present disclosure, the following is a brief description of the specific structure of the lower coal bed methane fishbone horizontal well:
fig. 1 is a schematic structural diagram of a coal bed methane fishbone horizontal well provided by an embodiment of the present disclosure, and as shown in fig. 1, the coal bed methane fishbone horizontal well includes a straight well section 1, a deflecting section 2, and a horizontal section 3 connected in sequence, where the horizontal section 3 includes a main wellbore 31 and a plurality of branch wellbores connected to the main wellbore 31.
Wherein, the horizontal section 3 comprises 6 lateral boreholes, and the 6 lateral boreholes are respectively the 1 st lateral borehole 321, the 2 nd lateral borehole 322, the 3 rd lateral borehole 323, the 4 th lateral borehole 324, the 5 th lateral borehole 325 and the 6 th lateral borehole 326.
By arranging the branch boreholes, the leakage area of the reservoir can be increased, and the yield of the coal bed gas is increased.
It should be noted that, as shown in fig. 1, the main wellbore trajectory of the coal bed methane fishbone horizontal well provided by the embodiment of the present disclosure is arranged along an upward-inclination direction of an upward-inclination coal bed, where the upward-inclination direction is a direction in which a trend gradually approaches to the ground. On one hand, when the main well track is arranged along the upward inclination direction, the drainage and production well cave is positioned at the lower part, and water and ash can enter the drainage and production well cave. On the other hand, when the main well track is arranged along the upward inclination direction, the included angle between the branch well and the horizontal plane is increased, and sidetracking of the branch well can be facilitated.
Optionally, the interval between two adjacent branch well bores is 100-200 m, and the length of each branch well bore is 200-300m, so as to ensure that each branch well bore can play a role in increasing the leakage area of the reservoir stratum, and further increasing the yield of the coal bed gas.
In the embodiment, the length of the main borehole 31 is 800-1500m, so as to facilitate the subsequent coal bed gas exploitation.
It should be noted that the length of the main borehole 31, the length of each branch borehole, and the interval between two adjacent branch boreholes 32 can also be set according to actual needs, and the disclosure is not limited thereto.
Fig. 2 is a flowchart of a construction method of a coal bed methane fishbone horizontal well provided in an embodiment of the present disclosure, and as shown in fig. 2, the construction method includes:
As shown in fig. 1, the horizontal section 3 includes a main borehole 31 and 6 branch boreholes connected to the main borehole 31.
In the present embodiment, the branch boreholes are symmetrically arranged on the main borehole 31 in a fishbone shape, and are equal to each other in the left and right directions.
And 203, in the process of drilling the horizontal section, lowering a main protective pipe with permeability into the main well bore of the drilled horizontal section, and respectively lowering a plurality of supporting pipes with permeability into a plurality of branch well bores of the drilled horizontal section.
As shown in fig. 1, a main casing 41 is lowered into the main bore 31, and branch casings 42 (only one of which is shown) are lowered into the respective branch bores.
According to the embodiment of the horizontal well drilling method and the horizontal well drilling device, the drilling tool is used for drilling the straight well section and the deflecting section which are sequentially connected, then the horizontal section is drilled, and when the horizontal section is drilled, the main protective pipe with permeability is lowered into the main well hole of the drilled horizontal section, and the main protective pipe can guarantee the stability of the main well hole of the horizontal well horizontal section. Simultaneously, a plurality of supporting pipes with permeability are respectively put into a plurality of branch well bores of the drilled horizontal section. The multiple supporting pipes can enhance the stability of multiple branch boreholes, effectively prevent adverse effects caused by collapse and blockage of the branch boreholes, and are beneficial to efficient and safe development of the coal bed gas horizontal well.
Fig. 3 is a flowchart of another construction method of a coal bed methane fishbone horizontal well provided in an embodiment of the present disclosure, and as shown in fig. 3, the construction method includes:
and 301, drilling a straight well section and a deflecting section which are connected in sequence by using a drilling tool.
In the present embodiment, as shown in fig. 1, the straight well section 1 is disposed in a vertical direction, and the deflecting section 2 is a curved structure.
Illustratively, step 302 may include:
in a first step, a main wellbore is divided into a plurality of sections according to the positions of a plurality of branch wellbores.
Optionally, the horizontal section comprises N sections of main boreholes and N-1 branch boreholes, N being a positive integer greater than 0. Two adjacent sections of main boreholes are separated by a branch borehole. The p-th branch well hole is positioned at the terminal of the m-th section of main well hole, m and p are positive integers larger than 0, m is smaller than or equal to N, p is smaller than or equal to N-1, and the terminal of the m-th section of main well hole is one end far away from the deflecting section. The N sections of main boreholes are communicated in sequence to form a main borehole 31.
Illustratively, as shown in FIG. 1, the horizontal section includes 7 main wellbores and 6 lateral wellbores. The 7 sections of main boreholes 31 are respectively a 1 st section of main borehole 311, a 2 nd section of main borehole 312, a 3 rd section of main borehole 313, a 4 th section of main borehole 314, a 5 th section of main borehole 315, a 6 th section of main borehole 316 and a 7 th section of main borehole 317 which are connected in sequence.
The 1 st main borehole 311 is a section of main borehole connected with the deflecting section 2, and the 7 th main borehole 317 is a section of main borehole farthest from the deflecting section 2. The 1 st lateral bore 321 is located at the terminal end of the 1 st main bore 311, and the 7 th main bore is terminated without a lateral bore.
And secondly, respectively drilling a plurality of sections of main boreholes and a plurality of branch boreholes by using a drilling tool.
Illustratively, starting from the 1 st main borehole, the following steps are repeated until the drilling tool is taken out after the N main boreholes and the N-1 branch boreholes are drilled:
drilling a p-th branch borehole after drilling the m-th section of main borehole;
and returning to the terminal of the m section of main borehole, and continuously drilling the m +1 section of main borehole according to the extension direction of the main borehole.
Illustratively, as shown in fig. 1, in the present embodiment, a 1 st main borehole 311 may be drilled, a 1 st branch borehole 321 may be drilled, and then a 2 nd main borehole 312, a 2 nd branch borehole 322, a 3 rd main borehole 313, a 3 rd branch borehole 323, a 4 th main borehole 314, a 4 th branch borehole 324, a 5 th main borehole 315, a 5 th branch borehole 325, a 6 th main borehole 316, a 6 th branch borehole 326, and a 7 th main borehole 317 may be drilled in sequence.
By adopting the advancing drilling mode, the smooth passage from the 1 st section of main borehole to the Nth section of main borehole can be ensured, so that the main protective pipe can be conveniently lowered into the main borehole in the subsequent process.
In this embodiment, each branch wellbore is drilled by a suspended sidetrack drilling method. After drilling of all the main well bores and the branch well bores is completed, the finally formed horizontal section is basically a straight line, and the final lowering of the main protective pipe is facilitated.
The suspended sidetracking refers to sidetracking construction operation directly performed under the condition of not injecting ash and not filling a well.
In this embodiment, the main protection pipe and the supporting pipe with permeability may be pipes made of materials with permeability, or may be made of materials with permeability by making holes on the pipes. When the multi-branch horizontal well system disclosed by the invention is adopted to mine coal bed gas, even if part of small-particle stratum substances flow into the main protective pipe and block the main protective pipe after being accumulated, the flushing pipe can be simply lowered into the main protective pipe, and water flow with certain pressure is applied to flush the accumulated substances in the main protective pipe so as to dredge the main protective pipe.
Illustratively, step 303 may include:
after each branch well hole is drilled, a supporting pipe is put into the corresponding branch well hole, and after the multiple sections of main well holes are drilled, a main protecting pipe is put into the main well hole.
Illustratively, each time a lateral is drilled, an optical drill string is run into the lateral;
injecting the support pipe into the optical drill rod for a preset length and then shearing;
and pumping the supporting pipe into the branch well hole through the drill pipe for anchoring, and reserving a set distance between the tail end of the supporting pipe and the deflecting point of the main well hole.
Wherein the set distance can be 30-50 cm. By reserving a certain set distance, the support pipe can be prevented from influencing later-stage drilling and descending into the main protective pipe.
Alternatively, the supporting pipe is a polyethylene plastic screen, i.e. a PE screen, and the process of pumping the PE screen into the branch wellbore through the drill pipe and anchoring may include:
in this embodiment, each time a branch borehole is drilled, an optical drilling rod is put into the bottom of the branch borehole (i.e. the end of the branch borehole far from the main borehole), and a 2m pocket is reserved (the "pocket" refers to a well section which is continuously drilled after the lowest destination layer is drilled for casing, well logging and the like in the drilling operation) so as to facilitate the subsequent PE screen pipe to be taken out of the drilling rod.
The PE sieve pipe injection device is installed at the wellhead of the horizontal well, a roller provided with the PE sieve pipe is placed on the ground, a sieve pipe guiding and anchoring device is installed at the front end of the PE sieve pipe, and then the PE sieve pipe is connected to the sieve pipe injection device. And (4) starting the PE screen pipe injection device, and slowly injecting the PE screen pipe into the drill pipe. And with the continuous injection of the PE sieve tube, the injection force of the injection device of the PE sieve tube is gradually increased to realize the injection of the sieve tube with the preset length. After the sieve tube with the preset length is injected, cutting off the sieve tube at the wellhead of the engineering horizontal well, removing the PE sieve tube injection device, connecting the drill rod with an upper drill rod, starting a drilling fluid pump to circulate drilling fluid, injecting the PE sieve tube to the tail end of the last drill rod, and ensuring that the guiding and anchoring device rushes out of the drill rod; the drill pipe is then gradually pulled out, and the PE screen is secured in the coal seam by the guiding and anchoring device.
After drilling one branch well hole each time, repeating the steps until a plurality of branch well holes are drilled with the support pipes.
Alternatively, the main casing may be a large-diameter steel pipe screen with certain strength. The pipe wall of the main protective pipe is provided with a plurality of groups of through holes. For example, the main protective pipe is a polyethylene plastic pipe with 8-16 holes/root, and the holes are designed to be in a 18mm × 25mm long circle shape, so that the influence on the strength of the sieve pipe can be reduced while the flow passage is effectively ensured to flow.
Illustratively, after drilling each of the plurality of sections of the main wellbore, running a main casing in the main wellbore may include:
a combined optical drill rod with a drill bit is put into the main well for drifting;
and arranging a pressurizing device at the wellhead of the horizontal well, putting the support pipe into the main well hole through the pressurizing device, leaving a 2-3m pocket at the bottom of the well, and taking out the combined optical drill rod with the drill bit.
Optionally, the construction method may further include:
and after drilling each branch well hole, introducing the drilling fluid into the horizontal well to circularly bring out the rock debris at the bottom of the well through the drilling fluid, circulating twice, and continuing to perform the next drilling.
After the multi-section main well hole and the plurality of branch well holes are drilled, the drilling fluid is introduced into the horizontal well, so that rock debris at the bottom of the well is circularly brought out through the drilling fluid, and the circulation is carried out twice.
And step 304, treating the sidetracking points of the plurality of branch well bores by adopting a hydraulic jetting method.
Illustratively, step 304 may include:
in the first step, a hydrajetting tool is run into the main wellbore using a fracturing apparatus.
And step two, starting from the N-1 th branch well hole, repeating the following steps until all the lateral drilling points of the N-1 branch well holes are subjected to hydraulic jetting, and taking out a hydraulic jetting tool:
moving the hydrajetting tool to the p-th lateral wellbore;
and carrying out hydraulic sand blasting on the sidetrack point of the p-th branch well hole, and forming a cave passage at the sidetrack point of the p-th branch well hole.
And returning to the terminal of the m-1 section of the main well bore, and performing hydraulic sand blasting on the sidetrack point of the p-1 branch well bore by using a hydraulic jet tool to form a cave channel at the sidetrack point of the p-1 branch well bore.
Wherein, the N-1 branch borehole is one branch borehole which is farthest away from the deflecting section in the N-1 branch boreholes.
It should be noted that, when hydraulic jetting is performed at the sidetracking point of each branch wellbore, the double-wall at each sidetracking point is damaged, and thereby, coal dust is generated. Therefore, after hydraulic jetting is carried out on the side drilling points of all branch well bores each time, drilling fluid is introduced into the horizontal well to take out coal dust through circulation of the drilling fluid, and therefore smoothness of a gas production channel is guaranteed.
The lateral drilling points of the main well bore and each branch well bore are treated in advance by adopting a hydraulic jet method, and the pulverized coal is circularly blown out of the well, so that the smoothness of a gas production channel of the coal seam can be guaranteed.
For example, as shown in fig. 1, in the present embodiment, the hydraulic injection may be performed at the sidetracking point b6 of the 6 th branch wellbore 326, and then the hydraulic injection may be performed at the sidetracking point b5 of the 5 th branch wellbore 325, the sidetracking point b4 of the 4 th branch wellbore 324, the sidetracking point b3 of the 3 rd branch wellbore 323, the sidetracking point b2 of the 2 nd branch wellbore 322, and the sidetracking point b1 of the 1 st branch wellbore 321 in turn.
By adopting the retreating type injection mode, the risk of rock debris generated by injection and the risk of injecting sand to bury the pipe string can be reduced, and the workload of pulling out and putting down the pipe string can be reduced.
Illustratively, the total liquid amount of each section of hydraulic jet construction parameter is 100-3Sand amount of 2-5m3The oil pipe displacement is 2m3Min to ensure effective injection at the double-wall of the sidetracking point of each branch well bore, thereby forming cave passages. The spraying effect can be judged on site according to the turned-out coal dust, and after spraying is completed, the shaft is circulated completely.
According to the embodiment of the horizontal well drilling method and the horizontal well drilling device, the drilling tool is used for drilling the straight well section and the deflecting section which are sequentially connected, then the horizontal section is drilled, and when the horizontal section is drilled, the main protective pipe with permeability is lowered into the main well hole of the drilled horizontal section, and the main protective pipe can guarantee the stability of the main well hole of the horizontal well horizontal section. Simultaneously, a plurality of supporting pipes with permeability are respectively put into a plurality of branch well bores of the drilled horizontal section. The multiple supporting pipes can enhance the stability of multiple branch boreholes, effectively prevent adverse effects caused by collapse and blockage of the branch boreholes, and are beneficial to efficient and safe development of the coal bed gas horizontal well. And the main well bore and the lateral drilling points of all branch well bores are processed in advance by adopting a hydraulic jetting method, so that the smoothness of a gas production channel of the coal seam can be guaranteed.
The embodiment of the disclosure also provides a coal bed gas exploitation method of the coal bed gas fishbone horizontal well, which includes:
and (3) discharging and mining by using a rodless pump in the coal bed gas fishbone horizontal well, wherein the coal bed gas fishbone horizontal well is obtained by adopting the construction method in the embodiment.
Wherein, the rodless pump is used for pumping, namely the rodless pump is used for lifting the water in the shaft to the ground, and the bottom hole flowing pressure is gradually reduced. And gradually forming a pressure drop funnel and gradually expanding outwards along with the reduction of the flow pressure at the bottom of the well, further gradually reducing the reservoir pressure of the coal bed, forcing the coal bed gas adsorbed on the inner surface of the pores of the coal matrix to be desorbed, then permeating and diffusing to natural fractures through the Darcy seepage flow of the pores of the matrix, and then permeating to a shaft from the fractures so as to be extracted.
Through the lower rodless pump drainage and production in the coal bed gas fishbone horizontal well, drainage and depressurization can be effectively realized, and the energy production is released to the maximum extent.
The above description is intended to be exemplary only and not to limit the present disclosure, and any modification, equivalent replacement, or improvement made without departing from the spirit and scope of the present disclosure is to be considered as the same as the present disclosure.
Claims (10)
1. The construction method of the coal bed gas fishbone horizontal well is characterized in that the coal bed gas fishbone horizontal well comprises a straight well section, a deflecting section and a horizontal section which are sequentially connected, the horizontal section comprises a main well bore and a plurality of branch well bores connected to the main well bore, and the construction method comprises the following steps:
drilling the straight well section and the deflecting section which are connected in sequence by using a drilling tool;
drilling the horizontal section using a drilling tool;
in the process of drilling the horizontal section, a main protective pipe with permeability is lowered into a main well bore of the drilled horizontal section, and a plurality of branch protective pipes with permeability are lowered into a plurality of branch well bores of the drilled horizontal section respectively.
2. The method of claim 1, wherein the drilling the horizontal section using a drilling tool comprises:
dividing the main wellbore into a plurality of sections according to the positions of the plurality of branch wellbores;
drilling sections of the main wellbore and the plurality of lateral wellbores, respectively, using a drilling tool;
in the process of drilling the horizontal section, a main protective pipe with permeability is lowered into a main well bore of the drilled horizontal section, and a plurality of branch protective pipes with permeability are lowered into a plurality of branch well bores of the drilled horizontal section respectively, wherein the process comprises the following steps:
and after each branch well hole is drilled, one branch pipe is put into the corresponding branch well hole, and after a plurality of sections of main well holes are drilled, the main protection pipe is put into the main well hole.
3. The method of claim 2, wherein the running of one of the support pipes in the corresponding lateral wellbore after each drilling of one of the lateral wellbores comprises:
each time one branch well hole is drilled, a light drill rod is put into the branch well hole;
injecting the supporting pipe into the optical drill rod for a preset length and then shearing;
and pumping the supporting pipe into the branch well hole through a drill pipe for anchoring, and reserving a set distance between the tail end of the supporting pipe and the deflecting point of the main well hole.
4. The construction method according to claim 3, wherein the set distance is 30 to 50 cm.
5. The construction method according to claim 2, wherein the horizontal section comprises N sections of the main well bores and N-1 branched well bores, wherein N is a positive integer greater than 0, and two adjacent sections of the main well bores are separated by one branched well bore;
the drilling of the sections of the main wellbore and the plurality of lateral wellbores, respectively, using a drilling tool, comprising:
from the 1 st section of the main borehole, repeating the following steps until the drilling tool is taken out after N sections of the main borehole and N-1 branch boreholes are drilled:
drilling a pth branch well hole after drilling the mth section of main well hole;
withdrawing to the terminal of the m section of the main borehole, and continuously drilling the m +1 section of the main borehole according to the extension direction of the main borehole;
the p-th branch well hole is positioned at the terminal of the m-th section of the main well hole, m and p are positive integers larger than 0, m is smaller than or equal to N, p is smaller than or equal to N-1, the terminal of the m-th section of the main well hole is one end far away from the deflecting section, and the 1-st section of the main well hole is one section of the main well hole connected with the deflecting section.
6. The construction method according to claim 5, wherein after drilling out the horizontal section and dropping out the main and supporting pipes, the construction method further comprises:
and treating the sidetracking points of the plurality of branch well bores by adopting a hydraulic jetting method.
7. The method of claim 6, wherein the treating the lateral drilling points of the plurality of lateral boreholes with hydrajetting comprises:
running a hydrajetting tool into the main wellbore using a fracturing apparatus;
repeating the following steps from the N-1 th branch well hole until the hydrajetting is carried out on the side drilling points of the N-1 branch well holes, and then taking out the hydrajetting tools:
moving the hydrajetting tool to a pth lateral wellbore;
hydraulically blasting at the sidetrack point of the p-th branch well hole to form a cave channel at the sidetrack point of the p-th branch well hole;
returning to the terminal of the main well bore of the (m-1) th section, and hydraulically blasting the sidetrack drilling point of the (p-1) th branch well bore by using the hydraulic jet tool to form a cave channel at the sidetrack drilling point of the (p-1) th branch well bore;
wherein the N-1 th branched well bore is the one of the N-1 branched well bores which is farthest away from the deflecting section.
8. The method of construction according to any one of claims 1 to 7 wherein the support pipe is a polyethylene plastic screen.
9. The construction method according to any one of claims 1 to 7, wherein the length of the main borehole is 800 to 1500m, the interval between two adjacent lateral boreholes is 100 to 200m, and the length of each lateral borehole is 200 to 300 m.
10. A coal bed gas exploitation method of a coal bed gas fishbone horizontal well is characterized by comprising the following steps:
and (3) discharging and mining by using a rodless pump in the coal bed gas fishbone horizontal well, wherein the coal bed gas fishbone horizontal well is obtained by the construction method according to any one of claims 1-9.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4076311A (en) * | 1975-01-29 | 1978-02-28 | Johns Robert W | Hydraulic mining from tunnel by reciprocated pipes |
| CN1924291A (en) * | 2006-07-27 | 2007-03-07 | 山东省煤田地质局第二勘探队 | Process for gas collection by a well with one mouth and multiple branches drilled along coal layer |
| CN102182403A (en) * | 2011-04-28 | 2011-09-14 | 王萍萍 | Drilling type well completion technology for fishbone branch borehole |
| CN102322252A (en) * | 2011-05-30 | 2012-01-18 | 北京奥瑞安能源技术开发有限公司 | Coal bed gas multi-branched horizontal well system and job practices thereof |
-
2020
- 2020-04-30 CN CN202010366295.XA patent/CN113585973A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4076311A (en) * | 1975-01-29 | 1978-02-28 | Johns Robert W | Hydraulic mining from tunnel by reciprocated pipes |
| CN1924291A (en) * | 2006-07-27 | 2007-03-07 | 山东省煤田地质局第二勘探队 | Process for gas collection by a well with one mouth and multiple branches drilled along coal layer |
| CN102182403A (en) * | 2011-04-28 | 2011-09-14 | 王萍萍 | Drilling type well completion technology for fishbone branch borehole |
| CN102322252A (en) * | 2011-05-30 | 2012-01-18 | 北京奥瑞安能源技术开发有限公司 | Coal bed gas multi-branched horizontal well system and job practices thereof |
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