CN104100244A - Well spacing method for coal bed gas communication well groups and application of well spacing method in fracturing yield increase - Google Patents
Well spacing method for coal bed gas communication well groups and application of well spacing method in fracturing yield increase Download PDFInfo
- Publication number
- CN104100244A CN104100244A CN201310128098.4A CN201310128098A CN104100244A CN 104100244 A CN104100244 A CN 104100244A CN 201310128098 A CN201310128098 A CN 201310128098A CN 104100244 A CN104100244 A CN 104100244A
- Authority
- CN
- China
- Prior art keywords
- well
- horizontal
- spacing method
- straight
- axis
- 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.)
- Pending
Links
Landscapes
- Earth Drilling (AREA)
Abstract
The invention relates to a well spacing method for a coal bed gas communication well group and application of the well spacing method in fracturing yield increase. In the method, coal bed gas can be efficiently mined by using a complex structure communication well consisting of a horizontal well and a straight well. By optimizing the horizontal well arrangement scheme in the well group, artificial fractures are produced as much as possible in the fracturing process of the horizontal wheel, opening of coal bed natural fractures is induced through the artificial fractures, and a large-area fracture grid is finally formed, so that the drainage and decompression speeds of a coal bed are increased, and the yield of a coal bed gas well is increased. Drainage and gas collecting work and pipeline gathering and transportation are only performed on the well group through the straight well, so that the pavement and manual maintenance of production pipelines are reduced, and the production cost is saved.
Description
Technical field
The invention belongs to and Coal-seam Gas Recovery Technologies field, relate to a kind of coal bed gas UNICOM's well group pattern of well and fracturing yield increasing method.
Background technology
Coal bed gas is that a kind of tax exists and in coal seam, take clean, the efficient unconventional natural gas that methane is main component.China has abundant coal bed gas resource, but coal seam reservoirs has " three is low " feature of low-permeability, low reservoir pressure and low gas content saturation ratio, and in drilling process, wellbore fluid pollutes nearly well coal seam in addition, to cbm development, brings very large difficulty.Simultaneously because coal bed gas is to adsorb or the mode of preserving is present in the hugger and matrix pores in coal seam, and coexist with coal seam Zhong Shui, exploiting coal bed methane will first make its desorb from hole and hugger wall get off.Therefore first coal-bed gas exploitation needs the water mining in coal seam to go out ground, strata pressure is declined gradually, when strata pressure is less than after coal bed gas desorption pressures, coal bed gas can be led to along cracks in coal seam or hole seepage flow and is plucked out of the ground to shaft bottom, and its mining principle and conventional gas and oil exploitation have very large difference.
The migration velocity of desorption gas is subject to the impact of cracks in coal seam width, connectedness.In carrying out drainage and step-down operation process, along with coal seam pressure decreased, Fracture Width in coal seam can diminish gradually, affect coal bed gas migration velocity, coal bed gas well all will produce man-made fracture through fracturing yield increasing transformation in object coal seam for this reason, and is induced and opened cracks in coal seam by man-made fracture, with this, increase coal bed gas flow area, improve speed of production.China adopts straight well to realize seam mining conventionally, and because straight well is controlled reserves finite volume, and fracturing reform hop count is generally one section, employs effective reserves limited.
Horizontal well has in exploitation oil-gas reservoir process that drainage area is large, well yield is high, reserves development degree advantages of higher, has become one of oil gas field enterprise-essential development scheme, and the revolutionary character effect of its generation shows day by day.In recent years, drilling level well cost is down to 1.5 to 2 times of straight well, and horizontal well production is 4 to 8 times of straight well, and horizontal well drilling sum almost exponentially increases.Along with cost, horizontal well has been applied to Fractured fracture, shale, sandstone and coal bearing seams, all types of oil reservoirs such as the exhausted oil reservoir of effective exploitation, tight gas reservoir.In order further to improve exploitation effect, the horizontal well technology formation many cracks that combines with staged fracturing renovation technique can significantly improve oil and gas production, and horizontal well being applied to girdle and implementing multistage pressure break is the effective method of exploiting coal bed methane.
The modern fracturing technique > of Economides(< < >, p156～158, in April, 2012) by hydraulic fracturing technology, in horizontal wellbore, produce man-made fracture, fracture extension direction is identical with region biggest principal stress direction, and crack wall and region minimum principal stress are perpendicular.
Soliman is in < < Review of Fractured Horizontal wells Technology > > (american petroleum academic conference, paper number SPE6289, 1997) in mention the relation that fracture pattern after fractured horizontal well depends primarily on horizontal wellbore axis direction and stratum biggest principal stress direction, after fractured horizontal well, fracture pattern mainly contains 3 kinds: when horizontal wellbore and region major principal stress angle are 0 °～30 °, produce one perpendicular to the transverse crack of horizontal wellbore, when being 80 °～90 °, horizontal wellbore and region major principal stress angle produce one along the longitudinal crack of horizontal wellbore, when being 30 °～80 °, horizontal wellbore and region major principal stress angle be easy to produce many cracks with horizontal well pit shaft oblique.For low permeability reservoir, along many transverse cracks of horizontal wellbore generation or oblique crack, make Oil/gas Well output increase multiple high more a lot of than longitudinal crack.
Chinese patent CN102606124A discloses many bunches of synchronous volume fracturing technologies of a kind of pair of horizontal well in segments, this technology is to arrange two mouthfuls of parallel horizontal wells, horizontal hole direction and region major principal stress angle are 90 °, thereby be convenient to fracturing volume increase construction, produce the transverse crack perpendicular to pit shaft.In horizontal well, carry out respectively multi-section multi-layer fracturing reform, in horizontal well is separately controlled reservoir region, producing many transverse cracks, then respectively to two mouthfuls of water plain execute to recover the oil produce.This technology implements to need two mouthfuls of pressure break horizontal wells must be parallel, and horizontal well is 90 ° with region biggest principal stress direction, has limited to a great extent that Oil/gas Well well spacing designs and pressing crack construction selects well, and practical is not strong.
Chinese patent CN102493790A discloses a kind of method for increasing yield of coal bed gas, comprises step: in the stable region of geologic structure, be drilled with mining straight well; The horizontal section wellbore that is drilled with horizontal well in the region of geologic structure complexity is communicated to mining straight well; After described horizontal section wellbore completes, along two, drive sleeve pipe and be lowered to horizontal segment sleeve pipe; Along described horizontal segment sleeve pipe, be lowered to steering drilling tool, via the connectivity points of described horizontal well and described mining straight well, be drilled with multi-branched horizontal well; Horizontal segment at described horizontal well is implemented pressure break completion.The method probing straight well and horizontal well, the two goes out to realize at straight well cave and crosses, then in horizontal well, be lowered to drilling tool and along different angles, bore a plurality of horizontal branch in intersection's probing, after having bored, then in horizontal well pressure break.The method is lowered to drilling well and drills a plurality of horizontal branch in intersection in coal seam water horizontal well, is very difficult to technically realize (shaft bottom limited space, drilling well is difficult to drill a plurality of branches).Even if realize, the later stage is during pressure break horizontal well, and due to cannot temporary plugging branch, bottom pressure conduction also can crush the subbranch of having drilled, and ickings stops up branch, and gas cannot circulate, and does not have production-increasing function.
Storing mode has determined that coal bed gas resource and tax exist in the conventional reservoirs such as sandstone, carbonate rock petroleum resources mining type method different, and design optimization labyrinth UNICOM well group pattern of well is the key that improves coal bed gas recovery ratio and economic benefit in conjunction with fracturing yield increasing method for this reason.Therefore, the problem existing is at present to research and develop a kind of coalbed methane well group pattern of well, and uses it for fracturing yield increasing.
Summary of the invention
Technical problem to be solved by this invention is for above-mentioned the deficiencies in the prior art, and a kind of coal bed gas UNICOM well group well spacing method is provided.The method forms labyrinth UNICOM well group by horizontal well and straight well.By optimizing horizontal well arrangement in well group, make horizontal well in fracturing process, produce man-made fracture as much as possible, and induce coal seam intrinsic fracture to open by man-made fracture, finally form large area fracture network, thereby improve coal seam drainage and step-down speed, increase Production of Coal-bed Gas Wells.The method only by straight well, well group is implemented to water pumping gas production work and pipeline collection defeated, reduce the laid and manpower of production flow line and safeguard, save cost of production.
For this reason, the invention provides a kind of coal bed gas UNICOM well group well spacing method, it comprises:
Steps A, the well head of straight well of take is the origin of coordinates, along region major principal stress S
2direction X-axis is set and plane right-angle coordinate is set on horizontal plane;
Step B, the position of layout horizontal well;
Step C, crosses the horizontal segment end of horizontal well and straight well and forms UNICOM's well group.
According to the present invention, in described step B, projection and the X-axis of the horizontal segment of described horizontal well on horizontal plane intersects.
In an embodiment of the invention, the angle that the projection of the horizontal segment of described horizontal well on horizontal plane forms along the positive direction of X-axis and X-axis is between 30 °～150 ° or 210 °～330 °.The projection of the horizontal segment of preferred described horizontal well on horizontal plane is 90 ° or 270 ° along the positive direction of X-axis and the angle of X-axis formation.
In yet another embodiment of the present invention, angle >=20 ° between the projection of the horizontal segment of adjacent two horizontal wells on horizontal plane.Can avoid like this fracturing section of adjacent two horizontal wells to merge mutually, avoid the phase mutual interference between crack that two horizontal wells produce, and increase can pressure break area.
According to the present invention, in described steps A, the positive direction of described X-axis and described maximum horizontal principal stress S
2direction identical or contrary.The positive direction of described Y-axis and described minimum level main stress bar S
1direction identical or contrary.
" the region major principal stress S of term described in the present invention
2" refer to the maximum horizontal principal stress S in coal bed gas block
2, be also called maximum horizontal principal stress S
2.
In the present invention, described term " is easy to produce the horizontal well direction of many man-made fractures " and refers to, projection and the region major principal stress S of its horizontal segment on horizontal plane
2direction form the direction of horizontal well of the angle of>=30 °.
In fact, technical scheme of the present invention is mainly according to coal bed gas block horizontal principal stress direction and is easy to produce the horizontal well direction of many man-made fractures, horizontal well in preferred arrangement UNICOM well group, arbitrarily the projection of the horizontal segment of water horizontal well on horizontal plane all should with region major principal stress S
2direction form the angle of>=30 °, like this can be so that multistage fracturing reform can produce more man-made fractures, and by induction coal seam intrinsic fracture unlatching formation large area fracture network, at utmost transform the coal seam in well group control area.Especially at the horizontal segment of any water horizontal well the projection on horizontal plane all should with region major principal stress S
2direction shape angle in 90 ° time, the pressure break hop count that multistage fracturing reform produces is maximum, can pressure break area maximum.
In a concrete embodiment, the horizontal segment of 4 mouthfuls of water horizontal wells at the projective distribution of horizontal plane in by region major principal stress S
2(X-axis) and region minimum principal stress S
1in 4 quadrant intervals of the plane right-angle coordinate that (Y-axis) forms, and the angle forming along the positive direction of X-axis and X-axis is between 30 °～150 ° or 210 °～330 °, wherein, projection and the region major principal stress S of the horizontal segment of any water horizontal well on horizontal plane
2formed angle>=30 ° of direction, and, angle>=20 ° between the projection of the horizontal segment of adjacent two mouthfuls of water horizontal wells on horizontal plane.
In another concrete embodiment, the angle that the horizontal segment of 2 mouthfuls of water horizontal wells forms along positive direction and the X-axis of X-axis in the projection of horizontal plane is between 30 °～150 ° or 210 °～330 °, wherein, projection and the region major principal stress S of the horizontal segment of any water horizontal well on horizontal plane
2formed angle>=30 ° of direction, preferred projection and the region major principal stress S of the horizontal segment of water horizontal well on horizontal plane arbitrarily wherein
2direction vertical, that is itself and region minimum principal stress S
1direction overlap, and, angle>=20 ° between the projection of the horizontal segment of adjacent two mouthfuls of water horizontal wells on horizontal plane.
According to the present invention, in described step e, that the hole pattern of described UNICOM well group is selected from is U-shaped, in V-type or W type at least one.Wherein, water horizontal well and straight well form U-shaped UNICOM well group arbitrarily.
In an embodiment of the invention, the well group hole pattern of recovery well is that two mouthfuls of horizontal saliva are put down the well group with straight well composition V-type UNICOM.Wherein, every saliva horizontal well and straight well form U-shaped UNICOM well group.
In yet another embodiment of the present invention, the well group hole pattern of recovery well is that three mouthfuls of horizontal saliva are put down the well group with straight well composition W type UNICOM.Wherein, every saliva horizontal well and straight well form U-shaped UNICOM well group.
In another embodiment of the invention, the well group hole pattern of recovery well is that five mouthfuls of horizontal saliva are put down the well group with straight well composition W+V type combination UNICOM.Wherein, every saliva horizontal well and straight well form U-shaped UNICOM well group.
According to the present invention, before described steps A, also comprise:
Step 1, definite area major principal stress S
2direction;
Step 2, probing straight well.
In the present invention, described horizontal well adopts cased hole completion mode or sieve tube completion mode to drill.Described straight well adopts cave completion mode probing.
According to the present invention, in described UNICOM well group, described horizontal well quantity mostly is 6 mouthfuls most.Preferred water horizontal well is 2～6 mouthfuls.Described straight well is 1 mouthful.
The present invention also further provides the above described coal bed gas UNICOM well group well spacing method application in fracturing yield increasing of a kind of basis, it comprises implements multistage fracturing reform to horizontal well, to produce fracture network in control area, and by straight well, realize well group water pumping gas production and work.
In an embodiment of the invention, will be applied to fracturing yield increasing according to above described coal bed gas UNICOM well group well spacing method, horizontal well will be implemented to multistage fracturing reform, with as follows in the principle of control area generation fracture network:
1) individual well pressure break scale increases gradually with the increase of construction hop count, and prevents that every section of man-made fracture from excessively extending communication adjacent level well;
2) mutually near water between horizontal well crack arrange and need mutually stagger, increase and link up area and also avoid crack to disturb;
3) in each fractured interval, perforation mode adopts shower hole, and perforation spacing 10～40m makes at fractured interval crack initiation many cracks, increases the probability of communicating with each other;
4) fracturing liquid adopts active water, and proppant is selected quartz sand, and average sand proportion is 10%(v/v)～15%(v/v), be beneficial to the formation of fracture network;
5) adopt ripe Staged Fracturing Technique In Horizontal Wells to implement multi-section multi-layer pressure break.
In the above-described embodiment, generation fracture network as much as possible in the coal seam reservoirs region of controlling at UNICOM's well group, water in coal seam is discharged fast, coal seam pressure drop, thereby accelerate degassed, the parsing in coal seam and the migration velocity of coal bed gas, reduce the draining time, significantly improve coal bed gas well recovery ratio; Only by straight well, can implement to carry out water pumping gas production work to many saliva horizontal well simultaneously, reduce the laid and manpower of surface production gathering line and safeguarded, reduce exploitation cost of production.Thereby make to be communicated with well group and control coal-bed gas exploitation benefit optimization in reservoir region.
Coal bed gas is that a kind of tax exists the unconventional natural gas in coal seam, and its mining principle and conventional gas and oil have very large difference.For increasing the gas production area in coal seam, improve coal bed gas well recovery ratio, the present invention adopts a kind of novel coal bed gas UNICOM well group well spacing method.The method forms labyrinth UNICOM well group by horizontal well and straight well can high-efficiency mining coal bed gas.By optimizing horizontal well arrangement in well group, make horizontal well in fracturing process, produce man-made fracture as much as possible, and induce coal seam intrinsic fracture to open by man-made fracture, finally form large area fracture network, thereby improve coal seam drainage and step-down speed, increase Production of Coal-bed Gas Wells.The present invention only by straight well, well group is implemented to water pumping gas production work and pipeline collection defeated, reduce the laid and manpower of production flow line and safeguard, save cost of production.
Accompanying drawing explanation
To the present invention, be further elaborated based on embodiment and with reference to accompanying drawing hereinafter:
Tu1Wei coal bed gas UNICOM well group well spacing method and the application schematic diagram in fracturing yield increasing thereof.
Fig. 2 is the cross sectional drawing of the U-shaped UNICOM well group that forms of the horizontal segment end of any water horizontal well and straight well.
Fig. 3 is that in embodiment 1, three mouthfuls of water horizontal wells and a bite straight well form the hole pattern of W type UNICOM well group and the application schematic diagram in fracturing yield increasing thereof.
Fig. 4 is that in embodiment 2, water horizontal well and a bite straight well form the hole pattern of U-shaped UNICOM well group and the application schematic diagram in fracturing yield increasing thereof.
Fig. 5 is that in embodiment 3, five mouthfuls of water horizontal wells and a bite straight well form the hole pattern of W+VXing UNICOM well group and the application schematic diagram in fracturing yield increasing thereof.
Fig. 6 is that in comparative example 1, three mouthfuls of water horizontal wells and a bite straight well form the hole pattern of W type UNICOM well group and the application schematic diagram in fracturing yield increasing thereof.
In figure, the implication of Reference numeral is as follows: A～F horizontal well, V straight well, S
1region minimum principal stress, S
2region major principal stress.
In the drawings, the well of same type and stress are indicated by identical Reference numeral.Accompanying drawing is not according to actual scale.
The specific embodiment
Below in conjunction with embodiment and accompanying drawing, describe the present invention in detail, these embodiment and accompanying drawing only play illustrative effect, are not limited to range of application of the present invention.
In Fig. 1, be achieved through the following technical solutions coal bed gas UNICOM well group well spacing, it comprises:
Step 1, definite area major principal stress S
2direction;
Step 2, adopts cave completion mode probing a bite straight well V;
Step 3, the well head of straight well V of take is the origin of coordinates, along region major principal stress S
2direction X-axis is set and plane right-angle coordinate is set on horizontal plane; The positive direction of described X-axis and described maximum horizontal principal stress S
2direction identical or contrary; The positive direction of described Y-axis and described minimum level main stress bar S
1direction identical or contrary;
Step 4, arrange the position of horizontal well, projection and the X-axis of the horizontal segment that makes described horizontal well on horizontal plane intersects, and the angle that the projection of the horizontal segment that makes horizontal well on horizontal plane forms along positive direction and the X-axis of X-axis is between 30 °～150 ° or 210 °～330 °, wherein, projection and the region major principal stress S of the horizontal segment of any water horizontal well on horizontal plane
2formed angle>=30 ° of direction, and, angle>=20 ° between the projection of the horizontal segment of adjacent two mouthfuls of water horizontal wells on horizontal plane;
Step 5, crosses the horizontal segment end of horizontal well A～F and straight well V and forms UNICOM's well group.
Horizontal well A～F is implemented to multistage fracturing reform, to produce fracture network in control area, and by straight well V, realize well group water pumping gas production and work.Horizontal well A～F adopts cased hole completion mode or sieve tube completion mode to drill.
For example, in as Fig. 2, the horizontal segment end of any water horizontal well A～F in Fig. 1 and straight well V cross and form the cross-section structure of U-shaped UNICOM well group.Wherein, straight well V adopts cave completion mode probing.
Again for example, in Fig. 3, three mouthfuls of horizontal saliva are put down with straight well V and are formed W type UNICOM well group, and three mouthfuls of water horizontal wells combinations can be a kind of combinations in CAD or EBF.
And for example, in Fig. 5, five mouthfuls of horizontal saliva are put down with straight well V and are formed W+V type combination UNICOM well group, and five mouthfuls of water horizontal wells combinations can be a kind of combinations in CADBE, CADBF, EBFAC or EBFAD.
When adopting two mouthfuls of water horizontal wells and straight well V combination, two mouthfuls of horizontal saliva are put down with straight well V and are formed V-type UNICOM well, and two mouthfuls of water horizontal well combinations can be a kind of combinations in CA, AD, EB or BF.The horizontal segment of two mouthfuls of water horizontal wells is at projection and the region major principal stress S of horizontal plane
2angle>=30 ° of direction, preferably projection and the region major principal stress S of the horizontal segment of horizontal well A wherein or B on horizontal plane
2direction vertical, that is itself and region minimum principal stress S
1direction overlap, and, angle>=20 ° between the projection of the horizontal segment of adjacent two mouthfuls of water horizontal wells on horizontal plane.
When adopting four-hole horizontal well to combine with straight well V, the horizontal segment of four-hole horizontal well at the projective distribution of horizontal plane in by region major principal stress S
2(X-axis) and region minimum principal stress S
1in 4 quadrant intervals of the plane right-angle coordinate that (Y-axis) forms, and the angle forming along the positive direction of X-axis and X-axis is between 30 °～150 ° or 210 °～330 °, wherein, projection and the region major principal stress S of the horizontal segment of any water horizontal well on horizontal plane
2formed angle>=30 ° of direction, and, angle>=20 ° between the projection of the horizontal segment of adjacent two mouthfuls of water horizontal wells on horizontal plane.
Above-mentioned coal bed gas UNICOM well group well spacing method is applied to fracturing yield increasing, and horizontal well is implemented multistage fracturing reform, according to following principle, implements, and produces as far as possible fracture network in control area, realizes well group water pumping gas production work by straight well V:
1) individual well pressure break scale increases gradually with the increase of construction hop count, and prevents that every section of man-made fracture from excessively extending communication adjacent level well;
2) mutually near water between horizontal well crack arrange and need mutually stagger, increase and link up area and also avoid crack to disturb;
3) in each fractured interval, perforation mode adopts shower hole, and perforation spacing 10～40m makes at fractured interval crack initiation many cracks, increases the probability of communicating with each other;
4) fracturing liquid adopts active water, and proppant is selected quartz sand, and average sand proportion is 10%(v/v)～15%(v/v), be beneficial to the formation of fracture network;
5) adopt ripe Staged Fracturing Technique In Horizontal Wells to implement multi-section multi-layer pressure break.
Embodiment
Embodiment 1:
As shown in Figure 3, three mouthfuls of water horizontal wells and a bite straight well form W type well group, and horizontal well is implemented to multi-section multi-layer fracturing reform, implement in accordance with the following steps:
1 definite area maximum horizontal principal stress S
2direction is 30 ° of norths by east, region minimum level main stress bar S
1direction is perpendicular.
2 probing a bite straight well V, straight well V adopts cave completion mode at stratum Reservoir Section.
3 to take straight well V well head be the origin of coordinates, along region major principal stress S
2direction X-axis is set and plane right-angle coordinate, the wherein positive direction of X-axis and described maximum horizontal principal stress S is set on horizontal plane
2direction identical or contrary; The positive direction of Y-axis and described minimum level main stress bar S
1direction identical or contrary.
4 probing water horizontal well A, the projection on horizontal plane of its horizontal segment is vertical with X-axis, and horizontal section length 800m adopts cased hole completion, and horizontal well end is intersected in straight well V cave.
5 probing water horizontal well D, this well location is in rectangular coordinate system first quartile, and the projection on horizontal plane of its horizontal segment and X-axis angle are 45 °, and horizontal section length 950m adopts cased hole completion, and horizontal well end is intersected in straight well V cave.
6 probing water horizontal well C, this well location is in rectangular coordinate system the second quadrant, and the projection on horizontal plane of its horizontal segment and X-axis angle are 135 °, and horizontal section length 950m adopts cased hole completion, and horizontal well end is intersected in straight well V cave.
7 according to A well horizontal section length, and fracture interval is principle according to 100m, at this well horizontal segment, can arrange 7 man-made fractures.Take the origin of coordinates as starting point crack on horizontal well pit shaft original position be respectively: 100m, 200m, 300m, 400m, 500m, 600m and 700m.Crack dummy joint length is followed successively by: 80m, 120m, 220m, 260m, 280m, 300m and 320m.
8 arrange 6 man-made fractures along D well horizontal segment, make the major fracture extension line of D well generation and the mid point that A well intersection point is positioned at adjacent two parallel fractures of A well.Can calculate each crack location of D well is respectively: 212m, 353m, 495m, 636m, 777m and 920m.Avoid crack excessively to extend and link up A well, crack dummy joint length is followed successively by: 100m, 150m, 240m, 260m, 280m and 300m.
9 arrange 6 man-made fractures along C well horizontal segment, make the major fracture extension line of C well generation and the mid point that A well intersection point is positioned at adjacent two parallel fractures of A well.Can calculate each crack location of C well is respectively: 212m, 353m, 495m, 636m, 777m and 920m.Avoid crack excessively to extend and link up A well, crack dummy joint length is followed successively by: 100m, 150m, 240m, 260m, 280m and 300m.
10 adopt pumping bridging plug staged fracturing technique to implement multistage fracturing reform to three mouthfuls of water horizontal wells, isolate fracturing fracture, thereby carry out multistage fracturing by set bridging plug in pit shaft.In fracturing process, fracturing liquid adopts active water; Sleeve pipe operational discharge capacity is at 5～7m
3/ min; Proppant is comprised of the quartz sand mixing of three kinds of particle size, and three kinds of particle size quartz sands are respectively: the coarse sand that the medium sand that the fine sand of particle diameter 0.3mm, particle diameter are 0.9mm, particle diameter are 1.2mm; The prepad fluid stage adds 2～3 fine sand sand plugs, and the load fluid stage be take medium sand as main, and the pressure break later stage adds a certain amount of coarse sand.According to single port horizontal well fracture length, fracturing liquid and quartz sand consumption increase gradually, guarantee to produce man-made fracture and are consistent with design length.
11 3 mouthfuls of well pressing crack constructions finish, and bridging plug in pit shaft is ground away, and 4 mouthfuls of wells are realized and being communicated with.
12 are lowered to oil pumper in straight well V, and 3 mouthfuls of pressure break horizontal wells in W type well group are carried out to drainage and step-down operation, and reclaim by straight well V the coal bed gas discharging in reservoir.
Embodiment 2:
As shown in Figure 4, water horizontal well and a bite straight well form U-shaped well group, and horizontal well is implemented to multi-section multi-layer fracturing reform, implement in accordance with the following steps:
1 definite area maximum horizontal principal stress S
2direction is 150 ° of norths by east, region minimum level main stress bar S
1direction is perpendicular.
2 probing a bite straight well V, straight well V adopts cave completion mode at stratum Reservoir Section.
3 take straight well V well head as the origin of coordinates is along region major principal stress S
2direction X-axis is set and plane right-angle coordinate, the wherein positive direction of X-axis and described maximum horizontal principal stress S is set on horizontal plane
2direction identical or contrary; The positive direction of Y-axis and described minimum level main stress bar S
1direction identical or contrary.
4 probing water horizontal well D, this well location is in rectangular coordinate system first quartile, and the projection on horizontal plane of its horizontal segment and X-axis angle are 35 °, and horizontal section length 700m adopts sieve tube completion, and horizontal well end is intersected in straight well V cave.
5 according to D well horizontal section length, and fracture interval is principle according to 100m, at this well horizontal segment, can arrange 6 man-made fractures.Take the origin of coordinates as starting point crack on horizontal well pit shaft original position be respectively: 100m, 200m, 300m, 400m, 500m and 600m.Crack dummy joint length is followed successively by: 200m, 220m, 240m, 260m, 280m and 300m.
6 adopt hydraulic perforation staged fracturing technique to implement multistage fracturing reform to horizontal well, activate corresponding spray gun implement multistage pressure break by ground pitching.In fracturing process, fracturing liquid adopts active water; Oil pipe operational discharge capacity is at 2.0～2.5m
3/ min, sleeve pipe operational discharge capacity is at 0.8～1.2m
3/ min; Proppant is comprised of the quartz sand mixing of three kinds of particle size, and three kinds of particle size quartz sands are respectively: the coarse sand that the medium sand that the fine sand of particle diameter 0.3mm, particle diameter are 0.9mm, particle diameter are 1.2mm; In hydraulic jet perforation process, select fine sand as abrasive material, liquid shoots away hole and by straight well V, discharges ground later; The prepad fluid stage adds 2～3 fine sand sand plugs, and the load fluid stage be take medium sand as main, and the pressure break later stage adds a certain amount of coarse sand.According to single port horizontal well fracture length, fracturing liquid and quartz sand consumption increase gradually, guarantee to produce man-made fracture and are consistent with design length.
7 fractured horizontal well constructions finish, and propose fracturing string.
8 are lowered to oil pumper in straight well V, and U-shaped well group is carried out to drainage and step-down operation, and reclaim by straight well V the coal bed gas discharging in reservoir.
Embodiment 3:
As shown in Figure 5, five mouthfuls of water horizontal wells and a bite straight well form W+V type well group, and horizontal well is implemented to multi-section multi-layer fracturing reform, implement in accordance with the following steps:
1 definite area maximum horizontal principal stress S
2direction is 80 ° of norths by east, region minimum level main stress bar S
1direction is perpendicular.
2 probing a bite straight well V, straight well V adopts cave completion mode at stratum Reservoir Section.
3 to take straight well V well head be the origin of coordinates, along region major principal stress S
2direction X-axis is set and plane right-angle coordinate, the wherein positive direction of X-axis and described maximum horizontal principal stress S is set on horizontal plane
2direction identical or contrary; The positive direction of Y-axis and described minimum level main stress bar S
1direction identical or contrary.
4 probing water horizontal well A, the projection on horizontal plane of its horizontal segment is vertical with X-axis, and horizontal section length 700m adopts cased hole completion, and horizontal well end is intersected in straight well V cave.
5 probing water horizontal well C, this well location is in rectangular coordinate system the second quadrant, and the projection on horizontal plane of its horizontal segment and X-axis angle are 135 °, and horizontal section length 950m adopts cased hole completion, and horizontal well end is intersected in straight well V cave.
6 probing water horizontal well D, this well location is in rectangular coordinate system first quartile, and the projection on horizontal plane of its horizontal segment and X-axis angle are 45 °, and horizontal section length 950m adopts cased hole completion, and horizontal well end is intersected in straight well V cave.
7 probing water horizontal well B, this well location is in rectangular coordinate system fourth quadrant, and the projection on horizontal plane of its horizontal segment and X-axis angle are 280 °, and horizontal section length 600m adopts sieve tube completion, and horizontal well end is intersected in straight well V cave.
8 probing water horizontal well E, this well location is in rectangular coordinate system third quadrant, and the projection on horizontal plane of its horizontal segment and X-axis angle are 235 °, and horizontal section length 720m adopts sieve tube completion, and horizontal well end is intersected in straight well V cave.
9 according to A well horizontal section length, and fracture interval is principle according to 100m, at this well horizontal segment, can arrange 7 man-made fractures.Take the origin of coordinates as starting point crack on horizontal well pit shaft original position be respectively: 100m, 200m, 300m, 400m, 500m, 600m and 700m.Crack dummy joint length is followed successively by: 80m, 120m, 220m, 260m, 280m, 300m and 320m.
10 arrange 6 man-made fractures along D well horizontal segment, make the major fracture extension line of D well generation and the mid point that A well intersection point is positioned at adjacent two parallel fractures of A well.Can calculate each crack location of D well is respectively: 212m, 353m, 495m, 636m, 777m and 920m.Avoid crack excessively to extend and link up A well, crack dummy joint length is followed successively by: 100m, 150m, 240m, 260m, 280m and 300m.
11 arrange 6 man-made fractures along C well horizontal segment, make the major fracture extension line of C well generation and the mid point that A well intersection point is positioned at adjacent two parallel fractures of A well.Can calculate each crack location of C well is respectively: 212m, 353m, 495m, 636m, 777m and 920m.Avoid crack excessively to extend and link up A well, crack dummy joint length is followed successively by: 100m, 150m, 240m, 260m, 280m and 300m.
12 according to B well horizontal section length, and fracture interval is principle according to 100m, at this well horizontal segment, can arrange 5 man-made fractures.Take the origin of coordinates as starting point crack on horizontal well pit shaft original position be respectively: 100m, 200m, 300m, 400m and 500m.Crack dummy joint length is followed successively by: 80m, 120m, 220m, 260m and 300m.
13 arrange 5 man-made fractures along E well horizontal segment, make the major fracture extension line of E well generation and the mid point that B well intersection point is positioned at adjacent two parallel fractures of B well.Can calculate each crack location of E well is respectively: 180m, 300m, 420m, 540m and 660m.Crack dummy joint length is followed successively by: 100m, 150m, 240m, 260m and 280m.
14 adopt pumping bridging plug staged fracturing technique to implement multistage fracturing reform to A well, C well and D well, isolate fracturing fracture, thereby carry out multistage fracturing by set bridging plug in pit shaft.In fracturing process, fracturing liquid adopts active water; Sleeve pipe operational discharge capacity is at 5～7m
3/ min; Proppant is comprised of the quartz sand mixing of three kinds of particle size, and three kinds of particle size quartz sands are respectively: the coarse sand that the medium sand that the fine sand of particle diameter 0.3mm, particle diameter are 0.9mm, particle diameter are 1.2mm; The prepad fluid stage adds 2～3 fine sand sand plugs, and the load fluid stage be take medium sand as main, and the pressure break later stage adds a certain amount of coarse sand.According to single port horizontal well fracture length, fracturing liquid and quartz sand consumption increase gradually, guarantee to produce man-made fracture and are consistent with design length.
15 adopt hydraulic perforation staged fracturing technique to implement multistage fracturing reform to E well and B well, activate corresponding spray gun implement multistage pressure break by ground pitching.In fracturing process, fracturing liquid adopts active water; Oil pipe operational discharge capacity is at 2.0～2.5m
3/ min, sleeve pipe operational discharge capacity is at 0.8～1.2m
3/ min; Proppant is comprised of the quartz sand mixing of three kinds of particle size, and three kinds of particle size quartz sands are respectively: the coarse sand that the medium sand that the fine sand of particle diameter 0.3mm, particle diameter are 0.9mm, particle diameter are 1.2mm; In hydraulic jet perforation process, select fine sand as abrasive material, liquid shoots away hole and by straight well V, discharges ground later; The prepad fluid stage adds 2～3 fine sand sand plugs, and the load fluid stage be take medium sand as main, and the pressure break later stage adds a certain amount of coarse sand.According to single port horizontal well fracture length, fracturing liquid and quartz sand consumption increase gradually, guarantee to produce man-made fracture and are consistent with design length.
16 ream the bridging plug milling in A well, C well and D well, and fracturing string in E well and B well is proposed, and 6 mouthfuls of wells are realized and being communicated with.
17 are lowered to oil pumper in straight well V, and W+V type well group is carried out to drainage and step-down operation, and reclaim by straight well V the coal bed gas discharging in reservoir.
Comparative example 1:
The comparative example 1 as different from Example 1 horizontal segment of horizontal well C and D projection and the X-axis angle on horizontal plane is respectively 20 ° and 170 °.
As shown in Figure 6, three mouthfuls of water horizontal wells and a bite straight well form W type well group, and horizontal well is implemented to multi-section multi-layer fracturing reform, implement in accordance with the following steps:
1 definite area maximum horizontal principal stress S
2direction is 30 ° of norths by east, region minimum level main stress bar S
1direction is perpendicular.
2 probing a bite straight well V, straight well V adopts cave completion mode at stratum Reservoir Section.
3 to take straight well V well head be the origin of coordinates, along region major principal stress S
2direction X-axis is set and plane right-angle coordinate, the wherein positive direction of X-axis and described maximum horizontal principal stress S is set on horizontal plane
2direction identical or contrary; The positive direction of Y-axis and described minimum level main stress bar S
1direction identical or contrary.
4 probing water horizontal well A, the projection on horizontal plane of its horizontal segment is vertical with X-axis, and horizontal section length 800m adopts cased hole completion, and horizontal well end is intersected in straight well V cave.
5 probing water horizontal well D, this well location is in rectangular coordinate system first quartile, and the projection on horizontal plane of its horizontal segment and X-axis angle are 20 °, and horizontal section length 950m adopts cased hole completion, and horizontal well end is intersected in straight well V cave.
6 probing water horizontal well C, this well location is in rectangular coordinate system the second quadrant, and the projection on horizontal plane of its horizontal segment and X-axis angle are 170 °, and horizontal section length 950m adopts cased hole completion, and horizontal well end is intersected in straight well V cave.
7 according to A well horizontal section length, and fracture interval is principle according to 100m, at this well horizontal segment, can arrange 7 man-made fractures.Take the origin of coordinates as starting point crack on horizontal well pit shaft original position be respectively: 100m, 200m, 300m, 400m, 500m, 600m and 700m.Crack dummy joint length is followed successively by: 80m, 120m, 220m, 260m, 280m, 300m and 320m.
The horizontal segment direction of 8D well and region major principal stress S
2angle is 20 °, because major fracture direction is identical with region major principal stress, so the horizontal segment angular separation of major fracture and D well is 20 °.For preventing linking up between adjacent crack, the well horizontal segment of D only can be arranged 4 man-made fractures.And due to major fracture direction and horizontal wellbore angle little, fracturing reform sweep area is greatly reduced.
The horizontal segment direction of 9C well and region major principal stress S
2angle is 10 °, because major fracture direction is identical with region major principal stress, so the horizontal segment angular separation of major fracture and C well is 20 °.For preventing linking up between adjacent crack, the horizontal segment of C well only can be arranged 3 man-made fractures, and due to major fracture direction and horizontal wellbore angle little, fracturing reform sweep area is greatly reduced.
By above-described embodiment and comparative example, can find out, when horizontal well horizontal segment direction and region major principal stress angle are less than 30 °, in horizontal well, pressure break hop count is restricted, and produces crack simultaneously and involves reservoir area and greatly reduce, thereby reduced to a great extent fracturing reform effect.
The foregoing is only preferred embodiment of the present invention, in order to limit the present invention, within the spirit and principles in the present invention not all, any modification of doing, be equal to replacement, improvement etc., within all should being included in protection scope of the present invention.
Claims (10)
1.Yi Zhong coal bed gas UNICOM well group well spacing method, it comprises:
Steps A, the well head of straight well of take is the origin of coordinates, along the direction of region major principal stress, X-axis is set and plane right-angle coordinate is set on horizontal plane;
Step B, the position of layout horizontal well;
Step C, crosses the horizontal segment end of horizontal well and straight well and forms UNICOM's well group.
2. well spacing method according to claim 1, is characterized in that, in described step B, projection and the X-axis of the horizontal segment of described horizontal well on horizontal plane intersects.
3. well spacing method according to claim 2, is characterized in that, the angle that the projection of the horizontal segment of described horizontal well on horizontal plane forms along the positive direction of X-axis and X-axis is between 30 °～150 ° or 210 °～330 °.
4. well spacing method according to claim 2, is characterized in that, the projection of the horizontal segment of described horizontal well on horizontal plane is 90 ° or 270 ° along the positive direction of X-axis and the angle of X-axis formation.
5. well spacing method according to claim 2, is characterized in that, angle >=20 ° between the projection of the horizontal segment of adjacent two horizontal wells on horizontal plane.
6. according to the well spacing method described in any one in the claims 1～5, it is characterized in that, in described steps A, the positive direction of described X-axis is identical or contrary with the direction of described region major principal stress.
7. according to the well spacing method described in any one in the claims, it is characterized in that, in described step e, that the hole pattern of described UNICOM well group is selected from is U-shaped, in V-type or W type at least one.
8. according to the well spacing method described in any one in the claims, it is characterized in that, before described steps A, also comprise:
Step 1, definite area biggest principal stress direction;
Step 2, probing straight well.
9. according to the well spacing method described in any one in the claims, it is characterized in that, in described UNICOM well group, described horizontal well quantity mostly is 6 mouthfuls most; Described straight well is 1 mouthful.
10. the application in fracturing yield increasing according to the well spacing method described in any one in the claims, it comprises implements multistage fracturing reform to horizontal well, to produce fracture network in control area, and by straight well, realizes well group water pumping gas production and works.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310128098.4A CN104100244A (en) | 2013-04-12 | 2013-04-12 | Well spacing method for coal bed gas communication well groups and application of well spacing method in fracturing yield increase |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310128098.4A CN104100244A (en) | 2013-04-12 | 2013-04-12 | Well spacing method for coal bed gas communication well groups and application of well spacing method in fracturing yield increase |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN104100244A true CN104100244A (en) | 2014-10-15 |
Family
ID=51668748
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310128098.4A Pending CN104100244A (en) | 2013-04-12 | 2013-04-12 | Well spacing method for coal bed gas communication well groups and application of well spacing method in fracturing yield increase |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104100244A (en) |
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104453836A (en) * | 2014-11-17 | 2015-03-25 | 中国石油天然气股份有限公司长庆油田分公司勘探开发研究院 | Multiple-stratum-series tight sandstone gas reservoir well spacing method |
| CN104790915A (en) * | 2015-04-22 | 2015-07-22 | 西南石油大学 | Coal bed methane recovery method |
| CN104818979A (en) * | 2015-04-03 | 2015-08-05 | 中国石油化工股份有限公司 | Construction process for coal bed gas V-shaped horizontal connected well |
| CN104963714A (en) * | 2015-04-30 | 2015-10-07 | 山西蓝焰煤层气集团有限责任公司 | Standing air shaft safe coal-uncovering technology of high gassy mine |
| CN104989330A (en) * | 2015-08-03 | 2015-10-21 | 中国神华能源股份有限公司 | Coalbed gas recovery method |
| CN105156089A (en) * | 2015-08-28 | 2015-12-16 | 中国神华能源股份有限公司 | U-shaped well system and well drilling method thereof |
| CN106640018A (en) * | 2016-11-02 | 2017-05-10 | 中国石油化工股份有限公司 | Method for mining coalbed gas through V-shaped well set |
| CN109386268A (en) * | 2017-08-03 | 2019-02-26 | 中国石油化工股份有限公司 | A kind of oil-gas reservoir reservoir fracturing method |
| CN110043229A (en) * | 2019-04-02 | 2019-07-23 | 广州海洋地质调查局 | A kind of more well group connection convergence recovery methods of Gas Hydrate In Sea Areas |
| CN112593910A (en) * | 2020-12-10 | 2021-04-02 | 山西晋城无烟煤矿业集团有限责任公司 | Efficient mining method for broken low-permeability coal bed gas short horizontal well group |
| CN113236219A (en) * | 2021-05-31 | 2021-08-10 | 重庆地质矿产研究院 | Coal bed gas fracturing method suitable for multiple sets of high and steep crushed coal beds |
| CN113738350A (en) * | 2020-05-29 | 2021-12-03 | 中国石油天然气股份有限公司 | Method for determining distribution area of residual coalbed methane resources in coalbed methane reservoir |
| CN115126469A (en) * | 2022-06-22 | 2022-09-30 | 中国地质大学（武汉） | Method and computer equipment for optimizing deployment of coal bed gas well pattern |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102418476A (en) * | 2011-10-24 | 2012-04-18 | 国鼎(大连)投资有限公司 | Deep coal and coal bed gas combined mining method |
| CN102817603A (en) * | 2012-08-15 | 2012-12-12 | 姚亚明 | Method communicating ground with underground mining coal bed gas |
-
2013
- 2013-04-12 CN CN201310128098.4A patent/CN104100244A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102418476A (en) * | 2011-10-24 | 2012-04-18 | 国鼎(大连)投资有限公司 | Deep coal and coal bed gas combined mining method |
| CN102817603A (en) * | 2012-08-15 | 2012-12-12 | 姚亚明 | Method communicating ground with underground mining coal bed gas |
Non-Patent Citations (3)
| Title |
|---|
| M.Y.SOLIMAN: "review of fractured horizontal wells technology", 《SOCIETY OF PETROLEUM ENGINEERS》, 16 April 1997 (1997-04-16) * |
| 付利: "煤层气开采井组合方案设计与分析", 《石油钻探技术》, vol. 40, no. 2, 31 March 2012 (2012-03-31) * |
| 张广清: "水平井水压致裂裂缝非平面扩展模型研究", 《工程力学》, vol. 23, no. 4, 30 April 2006 (2006-04-30) * |
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104453836A (en) * | 2014-11-17 | 2015-03-25 | 中国石油天然气股份有限公司长庆油田分公司勘探开发研究院 | Multiple-stratum-series tight sandstone gas reservoir well spacing method |
| CN104818979A (en) * | 2015-04-03 | 2015-08-05 | 中国石油化工股份有限公司 | Construction process for coal bed gas V-shaped horizontal connected well |
| CN104790915A (en) * | 2015-04-22 | 2015-07-22 | 西南石油大学 | Coal bed methane recovery method |
| CN104963714A (en) * | 2015-04-30 | 2015-10-07 | 山西蓝焰煤层气集团有限责任公司 | Standing air shaft safe coal-uncovering technology of high gassy mine |
| CN104989330A (en) * | 2015-08-03 | 2015-10-21 | 中国神华能源股份有限公司 | Coalbed gas recovery method |
| CN105156089A (en) * | 2015-08-28 | 2015-12-16 | 中国神华能源股份有限公司 | U-shaped well system and well drilling method thereof |
| CN106640018A (en) * | 2016-11-02 | 2017-05-10 | 中国石油化工股份有限公司 | Method for mining coalbed gas through V-shaped well set |
| CN109386268A (en) * | 2017-08-03 | 2019-02-26 | 中国石油化工股份有限公司 | A kind of oil-gas reservoir reservoir fracturing method |
| CN110043229A (en) * | 2019-04-02 | 2019-07-23 | 广州海洋地质调查局 | A kind of more well group connection convergence recovery methods of Gas Hydrate In Sea Areas |
| CN113738350A (en) * | 2020-05-29 | 2021-12-03 | 中国石油天然气股份有限公司 | Method for determining distribution area of residual coalbed methane resources in coalbed methane reservoir |
| CN112593910A (en) * | 2020-12-10 | 2021-04-02 | 山西晋城无烟煤矿业集团有限责任公司 | Efficient mining method for broken low-permeability coal bed gas short horizontal well group |
| CN113236219A (en) * | 2021-05-31 | 2021-08-10 | 重庆地质矿产研究院 | Coal bed gas fracturing method suitable for multiple sets of high and steep crushed coal beds |
| CN115126469A (en) * | 2022-06-22 | 2022-09-30 | 中国地质大学（武汉） | Method and computer equipment for optimizing deployment of coal bed gas well pattern |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104100244A (en) | Well spacing method for coal bed gas communication well groups and application of well spacing method in fracturing yield increase | |
| CN102080526B (en) | Method for extracting gas from bedding level fractured well of ground coal seam roof | |
| CN102852546B (en) | Method for pre-pumping coal roadway stripe gas of single soft protruded coal seam of unexploited area | |
| CN102913221B (en) | Volume transformation process of low permeability reservoir | |
| CN108009670B (en) | Optimization design method for improving supercritical carbon dioxide dry fracturing effect | |
| CN103967472B (en) | A kind of coal bed gas staged fracturing horizontal well enhanced gas extraction method | |
| CN107905834A (en) | A kind of hypotonic high prominent coal seam architecture gas production method | |
| CN103256025B (en) | A kind of composite well net type coal bed methane exploring method | |
| CN102392677A (en) | Permeability improvement technology for coal bed gas reservoir cap by using three-dimensional fracture network modification | |
| CN104806217A (en) | Combined separated layer fracturing, grouping and layer-combining mining method for coal bed well group | |
| CN102392678A (en) | Gas drainage method combining surface and underground fracturing and permeability improvement | |
| CN106194131A (en) | It is spaced CO between multistage fracturing horizontal well seam2oil flooding method | |
| CN104963671B (en) | A kind of fracturing reform method of High angle from formula well reservoir | |
| CN103510958B (en) | A kind of gentle dip super-high seam rock cross-cut coal uncovering | |
| CN103603643A (en) | Coal bed gas U-shaped well staged fracturing exploitation technology | |
| CN110306965A (en) | A kind of method for increasing for coal bed gas low yield wellblock | |
| CN104806285A (en) | Coal mine goaf gas control method based on ground horizontal well | |
| CN105804786B (en) | A kind of weak seam bottom plate layer-through drilling pressure rushes anti-reflection method | |
| CN108661618A (en) | Reservoir transformation method for L type horizontal well of coal bed gas | |
| CN102852490A (en) | High gas suction and discharge process method for complex well | |
| CN103161434A (en) | Mining method for low permeability reservoir of shale gas and the like | |
| CN102493831A (en) | Method for extracting coal seam gas through ground fracturing and underground horizontal drill holes | |
| CN109025940B (en) | CO for tight oil reservoir2Fracturing oil displacement integrated oil extraction method | |
| CN107152261A (en) | Coal bed gas extraction system and method for construction | |
| CN106640018A (en) | Method for mining coalbed gas through V-shaped well set |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20141015 |
|
| RJ01 | Rejection of invention patent application after publication |