CN103670271A - Dual-cycle relay coal bed well drilling method - Google Patents
Dual-cycle relay coal bed well drilling method Download PDFInfo
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Abstract
The invention discloses a dual-cycle relay coal bed well drilling method. The method comprises the following steps: (1) drilling and extracting: carrying out well cementation and enlarging a cave in a coal bed after drilling and completion twice and running casing; (2) drilling a horizontal multilateral well: through drilling and completion twice, after the second drilling and completion, running dual-casing to suspend and center an internal casing in an external casing, and placing the terminal of an internal casing on a place which is 0.5-10m far away from the casing shoe of the external casing; bypassing an extraction well while the third drilling is carried out, disconnecting the extraction wheel, and then drilling the extraction wheel after the construction of a horizontal multilateral well is finished; and (3) shutting in the well and putting into production in commission: cementing a plug, sealing the well head of the horizontal multilateral well, and pumping, draining and producing coal gas by using the extraction well. According to the drilling method, the double circulation above the casing shoe is formed, and coal dust at a horizontal naked eye section accelerates upward movement by virtue of the dual-circulation effect after the coal dust reaches the casing shoe, so that the stability and return flow of the drilling returning fluid can be improved, the sand-carrying capacity can be improved, and pipe-sticking accidents can be reduced or eliminated.
Description
Technical field
The present invention relates to CBM Drilling field of engineering technology, particularly relate to a kind of pair of continuous relay formula coal seam drilling method.
Background technology
At present, in CBM exploration and development, the mode that drilling technology generally all adopts brill horizontal branch well and mining well to combine both at home and abroad.Referring to Fig. 1, bore at present the main flow process of completion as follows:
1, bore mining well: after once spud in (hereinafter to be referred as " one opens ") bores completion, setting of casing, cement the well, then secondary spuds in after (opening hereinafter to be referred as two) bores completion, setting of casing and cements the well, and expands afterwards cave, coal seam; 2, bore horizontal branch well, setting of casing well cementation before entering horizontal segment, then make a call to one section of horizontal bare hole well with drilling rod tail band drill bit, and by directional technology, pass after mining straight well, in coal seam water plane, beat the Multilateral Wells of varying number; 3, cementing plug, envelope horizontal branch well well head; 4, utilize mining down-hole pump, draining and production coal gas.
In said method, mining well mainly plays two effects: the one, and draining and production coal gas after finishing drilling, the 2nd, air injection in boring horizontal branch well process, assists drilling fluid to take sand and underbalance.This method of leaning on the gas injection of mining well to increase circulation prop-carrying capacity can cause the unstable of well head pressure and returning fluid, and the risk of aggravation ickings precipitation and bit freezing, facts have proved larger side effect.Through data statistics, in 48 mouthfuls of Multilateral Wells that North China Oilfield company completes over nearly 5 years, only have 14 mouthfuls smoothly, there are 14 mouthfuls to collapse and bury drilling tool accident, loss amounts to expense approximately 20,000,000 RMB.Cause of accident is mainly as follows: 1, coal seam buried depth shallow (vertical depth < 700m), and poor diagenetic grade, the piece that easily collapses, this is natural quality; 2, at horizontal branch well, spud in for the third time and bore in bore hole process, due to annular space between drilling rod sleeve pipe large (spacing 33.0mm), it is low that drilling fluid returns speed, when ickings concentration is high, be not enough to whole ickings to recycle well head, cause ickings to stop up annular space, in addition coal seam bearing capacity is very low again, very easily pressed and leak, cause well head to lose and return, ickings is understood rapid precipitation and is buried dead drilling tool; 3,, during mining well air injection, except forming mixed gas drilling fluid, reduce in well back pressure (being underbalance) effect, also by gas itself, expansion helps take sand.But, because the bore hole borehole wall is irregular, at big hole place, form air cavity, when pressure is low can not with drilling fluid mixed, pressure reaches sudden outburst after certain value, there will be gas injection pressure and well head to return output cyclic fluctuation, thereby has aggravated hole collapse and bit freezing.
Summary of the invention
A kind of coal seam drilling method that the object of this invention is to provide exploration and development operation for coal bed gas, to solve, mining well air circulation is unstable and annular space large, return the problem a little less than the low and prop-carrying capacity of speed, while can be eliminated again the impact of easily collapsing in mining well gas injection coal seam, reduces or stop lock of tool drilling to occur.
For this reason, technical scheme of the present invention is as follows:
A pair continuous relay formula coal seam drilling method, comprises the following steps:
(1) bore mining well: spud in for twice bore completion, setting of casing after well cementation, expand cave, coal seam;
(2) bore horizontal branch well: by twice brill completion of spudding in, spudding in after finishing drilling for the second time, lower bilayer sleeve, is suspended in outer layer sleeve inner layer sleeve also placed in the middle, and the end of inner layer sleeve 0.5～10m more than the casing shoe of outer layer sleeve; Walk around described mining well spudding in for the third time while creeping into, be not first communicated with, after completing horizontal branch well construction, drill through described mining well;
(3) shut-in well and operation: cementing plug, envelope horizontal branch well well head, utilizes mining down-hole pump, draining and produce coal gas.
Preferably, in boring mining well process, spud in for the first time and adopt the drilling well of φ 311.15mm drill bit, after completion, lower φ 244.5mm sleeve pipe, makes cementing concrete return to ground afterwards; Spud in for the second time and adopt the drilling well of φ 215.9mm drill bit, lower φ 177.8mm sleeve pipe after completion, wherein coal seam section is used glass reinforced plastic sleeve, and it is high that cementing concrete returns to 200m, descends drill bit afterwards, and in Chu Kuo cave, coal seam, to diameter 0.4～0.7m, then coal seam section is buried in back-up sand.
Preferably, at horizontal branch well, bore in Completion Operations, spud in for the first time and adopt the drilling well of φ 444.5mm drill bit, lower φ 339.7mm sleeve pipe after completion, cementing concrete returns to ground; Spud in for the second time and adopt the drilling well of φ 311.15mm drill bit, kickoff point (KOP) 50～600m, the outer layer sleeve of lower φ 244.5mm, cementing concrete is minimum to be returned to 200m highly, descends the inner layer sleeve of φ 177.8mm to the above 0.5～10m of casing shoe of described φ 244.5mm sleeve pipe afterwards, makes it between two parties but does not cement the well, only as circulation, use, to replace mining well method of gas injection, at the next centralizer of every 3 inner layer sleeves of straight well section, at the next centralizer of every 1 inner layer sleeve of gradient section; Spud in for the third time and adopt the drilling well of φ 152.4mm drill bit, in drilling rod feed liquor, from feed liquor between described bilayer sleeve, drilling fluid between described bilayer sleeve returns and enters between drilling rod and described interior guide thimble on arriving after bottom sleeve footwear, recycles well head together with after the mixing of drilling well circulation fluid.
Boring method of the present invention, owing to having increased internal layer small casing, many liquid phase circulation passages, original drilling rod circulation has just formed two circulations more than casing shoe in addition.After ickings arrival casing shoe from horizontal bare hole section, rely on two similar relays of ringing equally to accelerate to return, thereby improved the stability of drilling well returning fluid and returned output, increase prop-carrying capacity, reduced or eliminated the generation of lock of tool drilling.Owing to taking sand without mining well air assisted, when creeping into, first walk around mining well (later stage is break-through again), so just avoided the impact that in the cyclic process of mining well, ickings collapses, more guaranteed to creep into safely and fast.
Accompanying drawing explanation
Fig. 1 is existing drilled well bore structural representation;
The drilled well bore structural representation of Fig. 2 for getting out by method of the present invention.
The specific embodiment
Of the present invention pair of continuous relay formula coal seam drilling method is divided into following three phases:
(1) bore mining well: spud in for twice bore completion, setting of casing after well cementation, expand cave, coal seam;
(2) bore horizontal branch well: by twice brill completion of spudding in, spudding in after finishing drilling for the second time, lower bilayer sleeve, inner layer sleeve is suspended in outer layer sleeve also placed in the middle, and the end of inner layer sleeve is at the above 0.5-10m of casing shoe of outer layer sleeve; Walk around described mining well spudding in for the third time while creeping into, be not first communicated with, after completing horizontal branch well construction, drill through described mining well;
(3) shut-in well and operation: after tripping out inner layer sleeve, at the suitable well section cementing plug of outer layer sleeve, shutoff horizontal branch well well head, utilizes mining down-hole pump, draining and produce coal gas.
Fig. 2 is a specific embodiment of the present invention, below in conjunction with Fig. 2, method of the present invention is described in further detail.For clarity sake illustrate with being convenient to, marked in the drawings corresponding drill bit and casing size.
As shown in Figure 1, two continuous relay formula coal seam drilling methods are divided into following three phases:
(1) the brill completion of mining well:
One opens: adopt drilling fluid, the drilling well of φ 311.15mm drill bit, and lower φ 244.5mm sleeve pipe, cementing concrete returns to ground;
Two open: adopt drilling fluid, the drilling well of φ 215.9mm drill bit, and lower φ 177.8mm sleeve pipe, wherein coal seam section is used glass reinforced plastic sleeve, and cementing concrete returns to 200m high, lower drill bit, in Chu Kuo cave, coal seam, diameter φ 0.7m, coal seam section is buried in back-up sand afterwards.
(2) horizontal branch well bores completion:
One opens: adopt drilling fluid, the drilling well of φ 444.5mm drill bit, and lower φ 339.7mm sleeve pipe, cementing concrete returns to ground;
Two open: adopt XXX drilling fluid, the drilling well of φ 311.15mm drill bit, kickoff point (KOP) 400m, lower φ 244.5mm outer layer sleeve, cementing concrete returns to 200m, descend afterwards the inner layer sleeve of φ 177.8mm to the above 2m of casing shoe of φ 244.5mm outer layer sleeve, in straight well section, the next centralizer of every 3 inner layer sleeves, at the next centralizer of every 1 inner layer sleeve of gradient section;
Three open (spudding in for the third time): adopt drilling fluid, the drilling well of φ 152.4mm drill bit, rely on two continuous relay formulas to take sand, walk around mining well, bore Multilateral Wells, finally drill through mining well.Wherein, described pair of continuous relay formula taken sand and is: in drilling rod feed liquor (feed liquor amount is Q1), from feed liquor between described bilayer sleeve (feed liquor amount is Q2), on after drilling fluid arrival bottom sleeve footwear between bilayer sleeve, return and enter between drilling rod and described interior guide thimble, recycle well head together with after the mixing of drilling well circulation fluid.
(3) shut-in well and operation: cementing plug, envelope horizontal branch well well head.Utilize mining down-hole pump, draining and production coal gas.
Below in conjunction with specific embodiments method of the present invention is illustrated.Concrete data in above-described embodiment are only for illustrative purposes, and can not be for limiting protection scope of the present invention.The corresponding improvement that those skilled in the art does according to aim of the present invention is all included within the scope of claim of the present invention.
Claims (3)
1. two continuous relay formula coal seam drilling methods, comprise the following steps:
(1) bore mining well: spud in for twice bore completion, setting of casing after well cementation, expand cave, coal seam;
(2) bore horizontal branch well: by twice brill completion of spudding in, spudding in after finishing drilling for the second time, lower bilayer sleeve, is suspended in outer layer sleeve inner layer sleeve also placed in the middle, and the end of inner layer sleeve 0.5～10m more than the casing shoe of outer layer sleeve; Walk around described mining well spudding in for the third time while creeping into, be not first communicated with, after completing horizontal branch well construction, drill through described mining well;
(3) shut-in well and operation: cementing plug, envelope horizontal branch well well head, utilizes mining down-hole pump, draining and produce coal gas.
2. according to claim 1 pair of continuous relay formula coal seam drilling method, is characterized in that: in boring mining well process, spud in for the first time and adopt the drilling well of φ 311.15mm drill bit, after completion, lower φ 244.5mm sleeve pipe, makes cementing concrete return to ground afterwards; Spud in for the second time and adopt the drilling well of φ 215.9mm drill bit, lower φ 177.8mm sleeve pipe after completion, wherein coal seam section is used glass reinforced plastic sleeve, cementing concrete returns to 200m high, descending afterwards drill bit, is 0.4m～0.7m at Chu Kuo cave, coal seam to diameter, and then coal seam section is buried in back-up sand.
3. according to claim 2 pair of continuous relay formula coal seam drilling method, is characterized in that: at horizontal branch well, bore in Completion Operations, spud in for the first time and adopt the drilling well of φ 444.5mm drill bit, descend φ 339.7mm sleeve pipe after completion, cementing concrete returns to ground; Spud in for the second time and adopt the drilling well of φ 311.15mm drill bit, kickoff point (KOP) 50～600m, the outer layer sleeve of lower φ 244.5mm, cementing concrete returns to minimum 200m high, descend afterwards the inner layer sleeve of φ 177.8mm to the above 0.5～10m of casing shoe of described φ 244.5mm sleeve pipe, form bilayer sleeve, at the next centralizer of every 3 inner layer sleeves of straight well section, at the next centralizer of every 1 inner layer sleeve of gradient section; Spud in for the third time and adopt the drilling well of φ 152.4mm drill bit, in drilling rod feed liquor, from feed liquor between described bilayer sleeve, drilling fluid between described bilayer sleeve returns and enters between drilling rod and described interior guide thimble on arriving after bottom sleeve footwear, recycles well head together with after the mixing of drilling well circulation fluid.
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN104060941A (en) * | 2014-06-19 | 2014-09-24 | 中国石油集团川庆钻探工程有限公司工程技术研究院 | Implantable type small wellbore continuous tube drilling method |
| CN106030022A (en) * | 2014-11-14 | 2016-10-12 | 斯特拉达设计有限公司 | Dual circulation fluid hammer drilling system |
| CN108316910A (en) * | 2017-09-20 | 2018-07-24 | 中国石油大学(北京) | The well pattern structure and development approach of deep layer bulk fractured reservoir are developed for gas drive |
| CN110748319A (en) * | 2019-10-12 | 2020-02-04 | 中国石油大学(北京) | Shale gas well casing deformation prevention well cementation method |
| CN112343555A (en) * | 2020-11-24 | 2021-02-09 | 中国海洋石油集团有限公司 | Relay well development method for expanding offshore oil and gas reserve utilization range |
| CN112627753A (en) * | 2020-12-23 | 2021-04-09 | 中煤水文局集团有限公司 | Method for maintaining mud circulation in lost-return stratum |
| CN113530438A (en) * | 2020-04-16 | 2021-10-22 | 中国石油化工股份有限公司 | Method for safely tripping up and down gas well nitrogen drilling pipe column and gas well structure |
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Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN104060941A (en) * | 2014-06-19 | 2014-09-24 | 中国石油集团川庆钻探工程有限公司工程技术研究院 | Implantable type small wellbore continuous tube drilling method |
| CN104060941B (en) * | 2014-06-19 | 2017-01-04 | 中国石油集团川庆钻探工程有限公司工程技术研究院 | A kind of implanted slim-hole continuous pipe boring method |
| CN106030022A (en) * | 2014-11-14 | 2016-10-12 | 斯特拉达设计有限公司 | Dual circulation fluid hammer drilling system |
| CN106030022B (en) * | 2014-11-14 | 2020-08-25 | 斯特拉达设计有限公司 | Dual cycle fluid hammer drilling system |
| CN108316910A (en) * | 2017-09-20 | 2018-07-24 | 中国石油大学(北京) | The well pattern structure and development approach of deep layer bulk fractured reservoir are developed for gas drive |
| CN108316910B (en) * | 2017-09-20 | 2024-04-26 | 中国石油大学(北京) | Well pattern structure and development method for gas drive development of deep massive fractured oil reservoirs |
| CN110748319A (en) * | 2019-10-12 | 2020-02-04 | 中国石油大学(北京) | Shale gas well casing deformation prevention well cementation method |
| CN113530438A (en) * | 2020-04-16 | 2021-10-22 | 中国石油化工股份有限公司 | Method for safely tripping up and down gas well nitrogen drilling pipe column and gas well structure |
| CN112343555A (en) * | 2020-11-24 | 2021-02-09 | 中国海洋石油集团有限公司 | Relay well development method for expanding offshore oil and gas reserve utilization range |
| CN112343555B (en) * | 2020-11-24 | 2022-11-18 | 中国海洋石油集团有限公司 | Relay well development method for expanding offshore oil and gas reserve utilization range |
| CN112627753A (en) * | 2020-12-23 | 2021-04-09 | 中煤水文局集团有限公司 | Method for maintaining mud circulation in lost-return stratum |
| CN112627753B (en) * | 2020-12-23 | 2022-05-31 | 中煤水文局集团有限公司 | Method for maintaining mud circulation in lost-return stratum |
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Effective date of registration: 20210720 Address after: 100007 No. 9 North Main Street, Dongcheng District, Beijing, Dongzhimen Patentee after: CHINA NATIONAL PETROLEUM Corp. Patentee after: CNPC Bohai Drilling Engineering Co.,Ltd. Address before: 300457 Tianjin Binhai New Area Development Zone Huanghai Road 106, Bohai Drilling Engineering Co., Ltd. science and Technology Development Office Patentee before: CNPC Bohai Drilling Engineering Co.,Ltd. |
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