CN103485760A - Full-size coal seam borehole stability evaluation method - Google Patents
Full-size coal seam borehole stability evaluation method Download PDFInfo
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- CN103485760A CN103485760A CN201310440202.3A CN201310440202A CN103485760A CN 103485760 A CN103485760 A CN 103485760A CN 201310440202 A CN201310440202 A CN 201310440202A CN 103485760 A CN103485760 A CN 103485760A
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- stability evaluation
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- 239000003245 coal Substances 0.000 title claims abstract description 66
- 238000011156 evaluation Methods 0.000 title claims abstract description 25
- 238000005553 drilling Methods 0.000 claims abstract description 26
- 239000004568 cement Substances 0.000 claims abstract description 15
- 239000012530 fluid Substances 0.000 claims abstract description 13
- 238000007789 sealing Methods 0.000 claims abstract description 9
- 238000011161 development Methods 0.000 claims abstract description 5
- 239000003818 cinder Substances 0.000 claims description 23
- 239000000463 material Substances 0.000 claims description 3
- 239000002023 wood Substances 0.000 claims description 3
- 238000000034 method Methods 0.000 abstract description 4
- 238000004088 simulation Methods 0.000 abstract description 3
- 238000002791 soaking Methods 0.000 abstract description 2
- 238000005086 pumping Methods 0.000 abstract 1
- 238000010276 construction Methods 0.000 description 8
- 238000005516 engineering process Methods 0.000 description 3
- 241001074085 Scophthalmus aquosus Species 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
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Abstract
The invention discloses a full-size coal seam borehole stability evaluation method, which is characterized by comprising the following steps of: it at least comprises the following steps: a. taking a same-layer raw coal block at a coal bed gas development area or a position near the coal bed gas development area and not more than 3 Km; b. placing the raw coal blocks in a box body, and sealing the periphery with cement to fix the raw coal blocks in the middle of the box body to form prefabricated blocks with the cement; c. drilling a hole in the middle of the precast block by using a drill, wherein the distance from the bottom of the drilled hole to the bottom of the box body is 10-12 cm; d. observing the micro-crack condition of the surface of the inner hole; e. pouring drilling fluid into the hole; f. soaking the drilling fluid for 7 days, and pumping out the drilling fluid; g. and observing the conditions of crack propagation, extension and chipping of the surface of the inner hole. Compared with the prior art, the method has the advantages that the simulation environment is closer to the reality, and the evaluation result is more accurate.
Description
Technical field
The present invention relates to the Coal seam drilling technology field, exactly relate to a kind of full-scale coal seam hole stability evaluation method of estimating for the coal seam hole stability.
Background technology
Due to the prosperity of coal seam reservoirs crack, the fragility height is frangible, cause in the coal seam drilling work progress, and the cave-in Frequent Accidents, the prevention and control difficulty is large.Therefore, before wellbore construction is carried out in coal seam, must at first to coal seam, carry out estimation of stability, according to the evaluation result of regularity of coal seam, carry out security measure targetedly.It is the primary work that CBM Drilling must complete, and is the technical guarantee of coal seam safety drilling.Current existing coal seam hole stability evaluation is to adopt and the ickings of coal seam to be bored with layer position, in the container (beaker) in laboratory, and by mud soak, the physical change after analyzing it and soaking, the stability in Indirect evaluation coal seam.There is larger defect in this traditional evaluation method, be that larger variation has all occurred for the cracked fracture pattern that becomes after ickings of coal cinder itself, stress state etc., differ larger with the real drilling well ocular environment in coal seam, the evaluation result that causes traditional evaluation method to obtain is poor to the directiveness of construction, has lost to a certain extent the meaning of carrying out coal seam hole stability evaluation.
Summary of the invention
The objective of the invention is the problems referred to above that exist in order to solve prior art, a kind of full-scale coal seam hole stability evaluation method is provided, this method is used the large scale coal cinder to carry out full-scale simulation, the more approaching reality of simulated environment, and evaluation result is more accurate.
Technical scheme of the present invention is: full-scale coal seam hole stability evaluation method is characterized in that: which comprises at least following steps:
A, be not more than 3Km place get one with a layer former coal cinder near cbm development area or its;
B, former coal cinder is placed in casing, the surrounding cement sealing, make former coal cinder be fixed on the casing middle part, with cement, forms prefabricated section;
C, use drill bit are in the boring of prefabricated section middle part, and foot of hole is 10-12cm apart from the distance of bottom half;
D, observation bore area microcrack situation;
E, pour drilling fluid in hole;
F, mud soak 7 days, extract drilling fluid out;
H, observe the bore area fracture propagation, extend, fall the piece situation.
Described casing is square, and it is of a size of 60*60*60cm, and this casing does not have lid, adopts wood materials.
Described drill bit is the coring bit that diameter is 216mm.
In described step b, while using cement sealing, wait solidifying 48 hours.
The size of described former coal cinder is not less than 40*40*40cm.
Advantage of the present invention is: the present invention has improved testing circumstance and the real similarity of boring construction environment of coal seam drilling that the coal seam hole stability is estimated, the result that makes coal seam hole stability evaluation obtain is Approaching Coal Seam wellbore construction reality more, improve the degree of accuracy of coal seam hole stability evaluation result, better instruct coal seam drilling, for the coal seam drilling construction provides technical support.The present invention is applicable to the coal seam drilling field, comprises coal bed gas well drilling well, coal seam relief well etc.
Below in conjunction with embodiment and accompanying drawing, the present invention will be further described, but not as a limitation of the invention.
The accompanying drawing explanation
Fig. 1 is the structural representation of casing of the present invention;
In figure, 1, casing; 2, cement; 3, hole; 4, drilling fluid; 5, former coal cinder.
The specific embodiment
Embodiment
The invention discloses a kind of full-scale coal seam hole stability evaluation method, which comprises at least following steps:
A, be not more than 3Km place get one and be of a size of 40*40*40cm with a layer former coal cinder 5 near cbm development area or its; Former coal cinder 5 is fixed, prevent in transportation, collision, form the secondary crack; The size of former coal cinder 5 also can be greater than 40*40*40cm, but can not surpass the size of casing 1.Select former coal cinder 5 to be not less than 40*40*40cm and be convenient to boring, former coal cinder is too small, and to be not suitable for adopting drill bit be the coring bit that diameter is 216mm, so just can't make testing circumstance and coal seam drilling reality brill construction environment be close.
B, former coal cinder 5 is placed in casing 1, cement 2 sealing for surrounding, make former coal cinder 5 be fixed on casing 1 middle part, with cement 2, forms prefabricated sections; While using cement sealing, wait solidifying 48 hours.Described casing 1 is square, and it is of a size of 60*60*60cm, and this casing does not have lid, adopts wood materials.This casing can wait cement to wait solidifying dismounting after 48 hours.
C, use drill bit are in prefabricated section middle part boring 3, and foot of hole is 10-12cm apart from the distance of bottom half; That is: bottom is left 10-12cm and is not drilled through; Described drill bit is the coring bit that diameter is 216mm.Adopt the moulding of once holing of the drill bit of this diameter, can not impact former coal cinder 5, improved and the real similarity of boring construction environment of coal seam drilling, effectively prevented that drill bit is improper simultaneously, repeatedly executed brill, caused the vibration to former coal cinder 5, thereby affected the accuracy of data.
D, observation bore area microcrack situation;
E, pour drilling fluid 4 in hole; Drilling fluid adopts wellbore construction clay-free drilling fluid commonly used, belongs to known technology and does not just elaborate here.
F, mud soak 7 days (168 hours), extract drilling fluid out;
H, observe the bore area fracture propagation, extend, fall the piece situation.
Finally, by steps d and the contrast of h observed result, provide the evaluation of hole stability.
The design parameter index:
Mud soak 7 days, observe coal cinder bore area crack width and reach 1.5-2mm, extended length, assert while extending to 20-30mm that the borehole wall just there will be to fall the piece situation.
The coal cinder that the present invention is larger by collected volume, used cement that its sealing, time are coagulated 48 hours.Then, use the drill bit unidimensional with treating the drilling well eye to hole on the cement sealing body, finally adopt drilling fluid to hole and soaked, the variation of holing after certain soak time by observation, estimate the stability in coal seam.This method is used the large scale coal cinder to carry out full-scale simulation, the more approaching reality of simulated environment, and evaluation result is more accurate.
The parts that the present embodiment does not describe in detail and technique belong to well-known components and the conventional means of the industry, here not narration one by one.
Claims (5)
1. full-scale coal seam hole stability evaluation method is characterized in that: which comprises at least following steps:
A, be not more than 3Km place get one with a layer former coal cinder near cbm development area or its;
B, former coal cinder is placed in casing, the surrounding cement sealing, make former coal cinder be fixed on the casing middle part, with cement, forms prefabricated section;
C, use drill bit are in the boring of prefabricated section middle part, and foot of hole is 10-12cm apart from the distance of bottom half;
D, observation bore area microcrack situation;
E, pour drilling fluid in hole;
F, mud soak 7 days, extract drilling fluid out;
H, observe the bore area fracture propagation, extend, fall the piece situation.
2. full-scale coal seam according to claim 1 hole stability evaluation method, it is characterized in that: described casing is square, and it is of a size of 60*60*60cm, this casing does not have lid, adopts wood materials.
3. full-scale coal seam according to claim 1 hole stability evaluation method, it is characterized in that: described drill bit is the coring bit that diameter is 216mm.
4. full-scale coal seam according to claim 1 hole stability evaluation method, is characterized in that: in described step b, while using cement sealing, wait solidifying 48 hours.
5. full-scale coal seam according to claim 1 hole stability evaluation method, it is characterized in that: the size of described former coal cinder is not less than 40*40*40cm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310440202.3A CN103485760B (en) | 2013-09-25 | 2013-09-25 | Full-size coal seam borehole stability evaluation method |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310440202.3A CN103485760B (en) | 2013-09-25 | 2013-09-25 | Full-size coal seam borehole stability evaluation method |
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| Publication Number | Publication Date |
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| CN103485760A true CN103485760A (en) | 2014-01-01 |
| CN103485760B CN103485760B (en) | 2016-08-17 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201310440202.3A Expired - Fee Related CN103485760B (en) | 2013-09-25 | 2013-09-25 | Full-size coal seam borehole stability evaluation method |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104535422B (en) * | 2015-01-04 | 2017-08-04 | 中国矿业大学 | A kind of method of simulation test drilling deformation |
| CN112668872A (en) * | 2020-12-25 | 2021-04-16 | 中法渤海地质服务有限公司 | Drilling block falling depth reduction method based on comprehensive similarity evaluation |
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|---|---|---|---|---|
| CN201574751U (en) * | 2009-09-28 | 2010-09-08 | 中国地质大学（武汉） | Testing device for simulating drilling and grouting in coal seam and evaluating stability of hole wall |
| CN102031954A (en) * | 2010-12-30 | 2011-04-27 | 河南理工大学 | Coal and rock bore hydraulic fracture experimental apparatus |
| CN102230373A (en) * | 2011-05-19 | 2011-11-02 | 中国石油大学(北京) | Method for determining safe drilling fluid density of coal bed based on structural element analysis model |
| CN202031564U (en) * | 2010-12-30 | 2011-11-09 | 河南理工大学 | Coal petrographic drilling hydraulic fracture experimental apparatus |
| GB2467464B (en) * | 2007-11-29 | 2012-10-24 | Schlumberger Holdings | Analyzing borehole by automatically evaluating predicted borehole failure image |
| CN102928273A (en) * | 2012-10-24 | 2013-02-13 | 河南理工大学 | Raw coal sample making method |
-
2013
- 2013-09-25 CN CN201310440202.3A patent/CN103485760B/en not_active Expired - Fee Related
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2467464B (en) * | 2007-11-29 | 2012-10-24 | Schlumberger Holdings | Analyzing borehole by automatically evaluating predicted borehole failure image |
| CN201574751U (en) * | 2009-09-28 | 2010-09-08 | 中国地质大学（武汉） | Testing device for simulating drilling and grouting in coal seam and evaluating stability of hole wall |
| CN102031954A (en) * | 2010-12-30 | 2011-04-27 | 河南理工大学 | Coal and rock bore hydraulic fracture experimental apparatus |
| CN202031564U (en) * | 2010-12-30 | 2011-11-09 | 河南理工大学 | Coal petrographic drilling hydraulic fracture experimental apparatus |
| CN102230373A (en) * | 2011-05-19 | 2011-11-02 | 中国石油大学(北京) | Method for determining safe drilling fluid density of coal bed based on structural element analysis model |
| CN102928273A (en) * | 2012-10-24 | 2013-02-13 | 河南理工大学 | Raw coal sample making method |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104535422B (en) * | 2015-01-04 | 2017-08-04 | 中国矿业大学 | A kind of method of simulation test drilling deformation |
| CN112668872A (en) * | 2020-12-25 | 2021-04-16 | 中法渤海地质服务有限公司 | Drilling block falling depth reduction method based on comprehensive similarity evaluation |
| CN112668872B (en) * | 2020-12-25 | 2022-11-15 | 中法渤海地质服务有限公司 | Drilling block falling depth reduction method based on comprehensive similarity evaluation |
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| CN103485760B (en) | 2016-08-17 |
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