CN108331573B - Waste oil well treatment method for coal mining area - Google Patents
Waste oil well treatment method for coal mining area Download PDFInfo
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- CN108331573B CN108331573B CN201711399200.9A CN201711399200A CN108331573B CN 108331573 B CN108331573 B CN 108331573B CN 201711399200 A CN201711399200 A CN 201711399200A CN 108331573 B CN108331573 B CN 108331573B
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- oil well
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B47/00—Survey of boreholes or wells
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B21/00—Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B29/00—Cutting or destroying pipes, packers, plugs, or wire lines, located in boreholes or wells, e.g. cutting of damaged pipes, of windows; Deforming of pipes in boreholes or wells; Reconditioning of well casings while in the ground
- E21B29/002—Cutting, e.g. milling, a pipe with a cutter rotating along the circumference of the pipe
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B33/00—Sealing or packing boreholes or wells
- E21B33/02—Surface sealing or packing
- E21B33/03—Well heads; Setting-up thereof
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B33/00—Sealing or packing boreholes or wells
- E21B33/10—Sealing or packing boreholes or wells in the borehole
- E21B33/13—Methods or devices for cementing, for plugging holes, crevices, or the like
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B7/00—Special methods or apparatus for drilling
Abstract
The waste oil well treatment method of the coal mining area comprises the steps of firstly detecting well-sealing cement and surface casing pipes, then respectively detecting whether cavities communicated with an aquifer exist in the waste oil well above the coal seam or not, detecting whether cavities communicated with the aquifer exist outside the surface casing pipes of the waste oil well above the coal seam or not, detecting the content of oil gas in the waste oil well and/or detecting the structural strength of a top plate of a coal face, classifying the waste oil well into different types of oil wells, and carrying out aboveground treatment and/or underground treatment based on the different types.
Description
Technical Field
The invention belongs to the field of mining, and particularly relates to a waste oil well treatment method for a coal mining area.
Background
China has a plurality of overlapping areas of coal resources and oil and gas resources, but literature data of related researches on the problem of safe and efficient exploitation of the overlapping areas of the coal resources and the oil and gas resources at home and abroad is not common at present. However, boreholes drilled under different historical conditions have poor sealing in different degrees in the field, and the boreholes often penetrate through a plurality of water-bearing formations, old kilns, water-bearing faults and the like. Because the attention degree is not enough, the drilling or the hydrological pore is not processed after use, and in the process of mining, the sealing of a bad borehole can become a mine water filling channel, so that the water filling condition of coal seam mining is complicated, great hidden danger is brought to the coal mine mining, and the safety production of the mine is threatened. The petroleum well also belongs to poor drilling, and only compared with common poor drilling, the petroleum drilling has larger threat to mine safety production, and the treatment of the common poor drilling has certain reference significance for plugging the petroleum drilling. Most researchers and engineers consider that the safety of drilling is not a single factor master control, but a result influenced by multiple factors such as geology, hydrogeology and mining activities, but can be roughly divided into: water source, construction, the influence of the mining activity and the quality of the borehole closure. However, at present, research on influence of the abandoned oil well on mine production at home and abroad is less, only a few individual mines have treatment experiences of the abandoned oil well, academic achievements made according to the treatment experiences are less, diffusion laws of oil, gas and water in the abandoned oil well and mine pressure laws of a coal bed in an affected area of the abandoned oil well are uncertain, and further research is needed. Therefore, the influence characteristics and laws of the drilling holes of the bad oil wells on the coal seam mining of the mines and the technical scheme and the safety technical measures of the excavation working face passing through the oil well influence area need to be further researched.
These wells in the field have a significant impact on the safe and efficient production of the mine. The mode of reserving the oil well to protect the coal pillar in the mine not only causes a large amount of coal resource loss, but also is difficult to normally arrange a coal face, and seriously influences high-efficiency production. The mine is mined in a mode of not reserving a waste oil well to protect a coal pillar, so that a series of major safety problems need to be solved: firstly, the construction age of the abandoned oil wells is long, the data is lack, the well body structure, the well shut-in condition, the oil layer characteristics and the like are not clear, a large amount of harmful gases such as hydrogen sulfide, methane and the like can be accumulated in the oil well and the vicinity thereof, and when the oil wells are exposed on the mining working face, the serious potential safety hazard that the harmful gases are gushed into the working face and even sprayed into the working face exists; secondly, the oil wells can still be communicated with oil layers with certain pressure, and when the oil wells are exposed on the mining working face, the possibility of oil flowing into the working face exists; thirdly, the oil wells can be communicated with aquifers and even ground water bodies, and when the oil wells are exposed on a mining working face, the possibility of sudden water burst exists; fourthly, a plurality of layers of alloy steel sleeves are generally sleeved in the oil wells and can play an anchoring role on local stratums, so that the existence of the steel sleeves can seriously affect the safety control of local top plates of a working surface; and fifthly, when the process that the mining working face passes through the oil wells, the multi-layer casing of the oil wells must be broken, so that the inexperience on how to safely break the casing of the oil wells and guarantee that the working face avoids roof accidents is guaranteed. The invention has important theoretical significance and practical application value for safe and efficient production of similar mines in China.
Disclosure of Invention
The invention aims to solve the technical problems and provides a treatment method of a waste oil well in a coal mining area, which can improve the treatment efficiency of the waste oil well through detection, classification and targeted treatment, remarkably improve the safety of coal mining work of a coal-bearing stratum in the coal mining area with the waste oil well through aboveground and underground treatment, improve the resource recovery rate of the coal mining area and avoid production risks.
The purpose of the invention is realized by the following technical scheme:
a method for treating a waste oil well in a coal mining area comprises the following steps:
and detecting whether the waste oil well in the coal mining area is provided with well sealing cement and a surface casing.
When the abandoned oil well has no sealing cement and no surface casing, detecting whether a cavity communicated with an aquifer exists at a position higher than a coal seam in the abandoned oil well and detecting the content of oil gas in the abandoned oil well; when the waste oil well has no well-sealing cement and a surface casing, detecting whether a cavity communicated with an aquifer exists at a position higher than a coal seam outside the surface casing of the waste oil well and detecting the content of oil gas in the waste oil well, and when the waste oil well has the well-sealing cement and the surface casing, detecting whether a cavity communicated with the aquifer exists at a position higher than the coal seam outside the surface casing of the waste oil well.
If the cavities and/or the oil and gas content exceeds the preset range, performing the aboveground treatment and the underground treatment, wherein the aboveground treatment comprises the following steps,
and (4) washing the well through the through hole, wherein the through hole comprises the steps of removing impurities in the surface casing, detecting the deformation degree of the surface casing and measuring the well depth, and washing the well to keep the well clean.
And logging, namely detecting the well cementation quality, the integrity of the surface casing, the well depth, the oil gas content in the well and the pressure of the oil gas content.
Plugging a surface casing pipe, making an artificial well bottom by penetrating holes until the height of the holes exceeds 100m of a coal seam, plugging a full well barrel by using cement slurry, injecting oil well cement slurry with the density of more than 2kg/L into the full well barrel, stopping grouting when the height of the cement slurry is 15-20m away from a well mouth, and waiting for setting.
Pressurizing and checking the seal, after the cement paste is subjected to waiting for setting in a shaft for 72 hours, pressurizing by a cement truck for 15Mpa, judging that the pressure is qualified if the pressure is reduced by not more than 0.5Mpa within 30 minutes, injecting a low-viscosity high-strength gel plugging material if the pressure is reduced by more than 0.5Mpa, and checking the pressure again after waiting for setting for 24 hours until the pressure is not reduced.
Plugging the well mouth, pouring cement slurry within 15-20m from the well mouth and returning the cement slurry to the well mouth, and drilling cement piers of 0.5m multiplied by 0.5m above the well mouth.
The aboveground treatment comprises the following steps of,
and (4) drilling and exploring holes, wherein the drilling and exploring holes gradually determine the position of the oil well when the oil well is exposed on the coal face.
Cutting the surface casing of the well.
And after cutting, plugging the abandoned oil well by 60m upwards, and plugging the abandoned oil well by cement downwards.
In the method for treating the waste oil wells in the coal mining area, when the waste oil wells have well-sealing cement and no surface casing, detecting the structural strength of a top plate of a coal face, and when the structural strength of the top plate of the coal face is smaller than a structural strength threshold value, performing underground treatment, wherein the underground treatment comprises the following steps of drilling and detecting holes, and when the oil wells are exposed on the coal face, the drilling and detecting holes gradually determine the positions of the oil wells; cutting the surface casing of the oil well; and after cutting, plugging the abandoned oil well by 60m upwards, and plugging the abandoned oil well by cement downwards.
In the treatment method of the waste oil well in the coal mining area, the logging is carried out by adopting a sound wave time difference method, a natural potential method or a natural gamma method, and the logging is detected in a circular range with the radius of 25cm by taking a well axis as a center.
In the method for treating the waste oil wells in the coal mining area, when the waste oil wells are 20m away from a coal face in the drilling exploration, the mining of the face is suspended, and 3 waste oil wells are drilled into the coal wall by a drilling machine, wherein the drilling depth is 30m, and the spacing is 10 m; when the working face is mined to 10m away from the waste oil well, drilling 9 20m drill holes with the distance of 2.5m on the coal wall by using a drilling machine; when the working face is mined to be 5m away from the waste oil well, 17 15m drill holes are drilled on the coal wall by a drilling machine, and the distance is 1.25 m; when the working face is mined to a distance of 2m from the waste oil well, 33 drill holes with the distance of 0.625m are drilled on the coal wall by a pneumatic drilling machine, wherein the drill holes with the distance of 2m are drilled on the coal wall; the drilling position is always vertical to the coal wall, when the drilling hole probes the position of the abandoned oil well, the specific position of the oil well is determined by encrypting the probing holes with the construction interval of 300mm near the probing holes, and then the abandoned oil well is exposed by constructing the probing roadway.
In the treatment method of the waste oil well in the coal mining area, a ball mill is adopted to cut a surface sleeve of the oil well, the cutting position of a surface oil pipe is 200mm higher than a top plate of a working surface and 200mm lower than a bottom plate of the working surface, and a deep pit with the side length not less than 1000mm multiplied by 1000mm and the depth not less than 1000mm is dug around the waste oil well.
In the treatment method of the waste oil well in the coal mining area, a gas concentration sensor for measuring methane, ethane, butane, pentane, carbon dioxide, carbon monoxide and/or hydrogen sulfide gas is arranged in the waste oil well.
In the treatment method of the abandoned oil well in the coal mining area, a stress sensor is arranged on a top plate of a coal mining working face, and a humidity sensor for measuring the water vapor content is arranged in the abandoned oil well and/or outside a surface casing pipe.
In the method for treating the abandoned oil well in the coal mining area, the abandoned oil well comprises a processor which sends an alarm based on the water vapor content, the oil gas content and/or the strength of a top plate of a coal face.
In the method for treating the waste oil well in the coal mining area, the processor comprises a general processor, a digital signal processor, an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), an analog circuit or a digital circuit.
In the method for treating the abandoned oil well in the coal mining area, the processor is provided with a memory, and the memory comprises one or more Read Only Memories (ROM), Random Access Memories (RAM), flash memories or Electrically Erasable Programmable Read Only Memories (EEPROM).
The above description is only an overview of the technical solutions of the present invention, and in order to make the technical means of the present invention more clearly apparent, and to make the implementation of the content of the description possible for those skilled in the art, and to make the above and other objects, features and advantages of the present invention more obvious, the following description is given by way of example of the specific embodiments of the present invention.
Drawings
Various other advantages and benefits of the present invention will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. It is obvious that the drawings described below are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.
In the drawings:
FIG. 1 is a schematic representation of the steps of a method of treating a depleted oil well in a coal recovery area in accordance with one embodiment of the present invention;
FIG. 2 is a schematic representation of the water conditions of a abandoned oil well without surface casing and without shut-in cement according to one embodiment of the present invention;
FIG. 3 is a schematic representation of the water conditions of a abandoned oil well with surface casing and no shut-in cement according to another embodiment of the present invention;
FIG. 4 is a schematic illustration of the oil and gas conditions of a abandoned oil well without surface casing and without shut-in cement according to an embodiment of the present invention;
FIG. 5 is a schematic representation of the hydrocarbon conditions of a abandoned well with surface casing and no shut-in cement according to an embodiment of the present invention;
FIG. 6 is a schematic illustration of water and hydrocarbon conditions for a abandoned oil well without surface casing and without shut-in cement according to an embodiment of the present invention;
FIG. 7 is a schematic illustration of water and roof conditions for a abandoned well having surface casing and well-plugging cement in accordance with an embodiment of the present invention;
FIG. 8 is a schematic illustration of water and roof conditions for a abandoned oil well having surface casing, cemented cement, and shut-in cement in accordance with an embodiment of the present invention;
FIG. 9 is a schematic illustration of the water and roof conditions of a abandoned well without surface casing, cemented cement, and with shut-in cement in accordance with an embodiment of the present invention;
FIG. 10 is a schematic illustration of water and roof conditions for a abandoned oil well without surface casing and without shut-in cement in accordance with an embodiment of the present invention;
FIG. 11 is a schematic representation of an uphole remediation process for waste well remediation of a coal recovery area in accordance with an embodiment of the present invention;
the invention is further explained below with reference to the figures and examples.
Detailed Description
Specific embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. While specific embodiments of the invention are shown in the drawings, it should be understood that the invention may be embodied in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
It should be noted that certain terms are used throughout the description and claims to refer to particular components. As one skilled in the art will appreciate, various names may be used to refer to a component. This specification and claims do not intend to distinguish between components that differ in name but not function. In the following description and in the claims, the terms "include" and "comprise" are used in an open-ended fashion, and thus should be interpreted to mean "include, but not limited to. The description which follows is a preferred embodiment of the invention, but is made for the purpose of illustrating the general principles of the invention and not for the purpose of limiting the scope of the invention. The scope of the present invention is defined by the appended claims.
For the purpose of facilitating an understanding of the embodiments of the present invention, the following description will be made in terms of several specific embodiments with reference to the accompanying drawings, and the drawings are not intended to limit the embodiments of the present invention.
The method for treating the abandoned oil well in the coal mining area according to the invention as shown in figure 1 comprises the following steps:
and detecting whether the waste oil well in the coal mining area is provided with well sealing cement and a surface casing.
When the abandoned oil well has no sealing cement and no surface casing, detecting whether a cavity communicated with an aquifer exists at a position higher than a coal seam in the abandoned oil well and detecting the content of oil gas in the abandoned oil well; when the waste oil well has no well-sealing cement and a surface casing, detecting whether a cavity communicated with an aquifer exists at a position higher than a coal seam outside the surface casing of the waste oil well and detecting the content of oil gas in the waste oil well, and when the waste oil well has the well-sealing cement and the surface casing, detecting whether a cavity communicated with the aquifer exists at a position higher than the coal seam outside the surface casing of the waste oil well.
And if the holes exist and/or the oil gas content exceeds the preset range, performing aboveground treatment and underground treatment, wherein the aboveground treatment comprises the following steps.
And (4) washing the well through the through hole, wherein the through hole comprises the steps of removing impurities in the surface casing, detecting the deformation degree of the surface casing and measuring the well depth, and washing the well to keep the well clean.
And logging, namely detecting the well cementation quality, the integrity of the surface casing, the well depth, the oil gas content in the well and the pressure of the oil gas content.
Plugging a surface casing pipe, making an artificial well bottom by penetrating holes until the height of the holes exceeds 100m of a coal seam, plugging a full well barrel by using cement slurry, injecting oil well cement slurry with the density of more than 2kg/L into the full well barrel, stopping grouting when the height of the cement slurry is 15-20m away from a well mouth, and waiting for setting.
Pressurizing and checking the seal, after the cement paste is subjected to waiting for setting in a shaft for 72 hours, pressurizing by a cement truck for 15Mpa, judging that the pressure is qualified if the pressure is reduced by not more than 0.5Mpa within 30 minutes, injecting a low-viscosity high-strength gel plugging material if the pressure is reduced by more than 0.5Mpa, and checking the pressure again after waiting for setting for 24 hours until the pressure is not reduced.
Plugging the well mouth, pouring cement slurry within 15-20m from the well mouth and returning the cement slurry to the well mouth, and drilling cement piers of 0.5m multiplied by 0.5m above the well mouth.
The aboveground treatment comprises the following steps.
And (4) drilling and exploring holes, wherein the drilling and exploring holes gradually determine the position of the oil well when the oil well is exposed on the coal face.
Cutting the surface casing of the well.
And after cutting, plugging the abandoned oil well by 60m upwards, and plugging the abandoned oil well by cement downwards.
In the preferred embodiment of the method for treating the waste oil wells in the coal mining area, when the waste oil wells have well-sealing cement and no surface casing, whether the roof of a coal face is possibly damaged by hanging roof and roof fall or not is detected, and when the roof of the coal face is damaged by hanging roof and roof fall, underground treatment is carried out, the underground treatment comprises the following steps of drilling and detecting holes, wherein the drilling and detecting holes gradually determine the positions of the oil wells when the oil wells are exposed on the coal face; cutting the surface casing of the oil well; and after cutting, plugging the abandoned oil well by 60m upwards, and plugging the abandoned oil well by cement downwards.
The waste oil well treatment method for the coal mining area comprises the steps of firstly detecting well-sealing cement and surface casing pipes, then respectively detecting whether cavities communicated with an aquifer exist in the position, higher than the coal seam, of the waste oil well or not and whether cavities communicated with the aquifer exist outside the surface casing pipes of the waste oil well or not through detection results, detecting the content of oil gas in the waste oil well and/or detecting whether suspended roof and roof fall hazards exist on a coal face or not, classifying the waste oil well into different types of oil wells and carrying out targeted treatment based on the different types of oil wells, remarkably improving the treatment efficiency of the waste oil well through aboveground treatment and underground treatment, improving the safety of coal mining work of the coal-bearing stratum of the coal mining area with the waste oil well, improving the resource recovery rate of the coal mining area and avoiding production risks.
In the preferable embodiment of the method for treating the abandoned oil well in the coal mining area, the logging is carried out by adopting a sonic time difference method, a natural potential method or a natural gamma method, and the logging is detected in a circular range with the radius of 25cm by taking a well axis as a center.
In the preferred embodiment of the method for treating the abandoned oil well in the coal mining area, in the drilling exploration, when the abandoned oil well is 20m away from the coal face, the mining of the face is suspended, a drilling machine is used for drilling holes on the coal wall, the drilling depth is 30m, the distance is 10m, and the total number of the drilling holes is 3; when the working face is mined to 10m away from the waste oil well, drilling 9 20m drill holes with the distance of 2.5m on the coal wall by using a drilling machine; when the working face is mined to be 5m away from the waste oil well, 17 15m drill holes are drilled on the coal wall by a drilling machine, and the distance is 1.25 m; when the working face is mined to a distance of 2m from the waste oil well, 33 drill holes with the distance of 0.625m are drilled on the coal wall by a pneumatic drilling machine, wherein the drill holes with the distance of 2m are drilled on the coal wall; the drilling position is always vertical to the coal wall, when the drilling hole probes the position of the abandoned oil well, the specific position of the oil well is determined by encrypting the probing holes with the construction interval of 300mm near the probing holes, and then the abandoned oil well is exposed by constructing the probing roadway.
In the preferable embodiment of the treatment method of the abandoned oil well in the coal mining area, the ball mill is adopted to cut the surface casing of the oil well, the cutting position of the surface oil pipe is 200mm higher than the top plate of the working face and 200mm lower than the bottom plate of the working face, and a deep pit with the side length of not less than 1000mm multiplied by 1000mm and the depth of not less than 1000mm is dug at the periphery of the abandoned oil well.
In a preferred embodiment of the method for treating a abandoned oil well in a coal mining area, a gas concentration sensor for measuring methane, ethane, butane, pentane, carbon dioxide, carbon monoxide and/or hydrogen sulfide gas is arranged in the abandoned oil well.
In the preferable embodiment of the treatment method for the abandoned oil well in the coal mining area, a stress sensor is arranged on a top plate of a coal face, and a humidity sensor for measuring the water vapor content is arranged in the abandoned oil well and/or outside a surface casing pipe.
In a preferred embodiment of the method of treating a abandoned oil well of a coal mining area of the present invention, the abandoned oil well includes a processor that sends an alert based on moisture content, oil and gas content, and/or coal face roof strength.
In the preferred embodiment of the method for treating the abandoned oil well in the coal mining area, the processor comprises a general processor, a digital signal processor, an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), an analog circuit or a digital circuit.
In a preferred embodiment of the method for treating a abandoned oil well in a coal mining area, the processor is provided with a memory, and the memory comprises one or more of a read only memory ROM, a random access memory RAM, a flash memory or an electrically erasable programmable read only memory EEPROM.
In one embodiment, the present invention can classify possible disasters into three categories, water disaster, oil and gas disaster, and roof disaster, according to the presence of surface casing and seal cement in the abandoned oil well structure. Water disasters are produced by the fact that an aquifer above a mined coal seam is collapsed into a working face through an oil well casing or a gap between the oil well casing and a rock stratum. Oil gas disasters are divided into two conditions, one is that oil gas is caused to flow into a working surface due to the conduction of a sleeve and a well bottom oil-gas reservoir, so that personnel are injured; the other is that oil gas existing in the coal-bearing stratum per se flows into a working face to cause personnel injury. The roof disaster refers to that the roof of the working face is suspended in a large area due to the super anchoring effect of the sleeve, and collapses in a certain period to generate storm wind, so that personnel are injured.
In a water disaster, in one embodiment, the water situation of a abandoned oil well without surface casing and without seal cement according to one embodiment of the invention is shown in fig. 2, wherein the surface casing is withdrawn, the abandoned oil well is formed with a cavity, the cavity is connected with a water-containing layer, the cavity does not form a water accumulation and water bursting channel due to the absence of the casing and the seal cement, and the water in the cavity is pushed to the oil well at the working surface and is burst into the working surface according to the situation shown in fig. 1. Because the water quantity in the hole is not large, but the water head height is large, high-pressure water can be generated in the process of exposure, and the water needs to be carefully treated in the process of making measures and needs to be treated underground and aboveground.
In one embodiment, fig. 3 is a schematic diagram of water conditions of a abandoned oil well with a surface casing and without sealing cement, wherein the abandoned oil well or a exploratory well does not withdraw the surface casing, does not perform the sealing work, and has no sealing cement, whether cavities communicated with an aquifer exist at the position higher than a coal seam outside the surface casing of the abandoned oil well is detected, and if the cavities exist, two times of water collapse is possible in the process of treating the oil well, and the water condition needs to be strictly noticed. Both downhole and uphole treatments are required.
In an oil and gas disaster, a channel is required to be formed in the oil and gas disaster, in an embodiment of the invention, as shown in fig. 4, a schematic diagram of an oil and gas situation of a abandoned oil well without a surface casing and without well-sealing cement is shown, wherein oil and gas may fill a cavity formed by the oil well, the oil and gas content in the abandoned oil well needs to be detected, when the oil and gas content exceeds a predetermined range, the abandoned oil well is marked as an oil and gas disaster well, when a working face is pushed to the place for treatment, the oil and gas may flow into the working face, harmful gases such as methane, ethane, butane, pentane, carbon dioxide, carbon monoxide, hydrogen sulfide and the like exist in the oil and gas, different gases need to be prevented and controlled in the process of disclosure, and meanwhile, the oil and gas pressure in the cavity is unknown, and the possibility of instantaneous large-amount inflow of. Both downhole and uphole treatments are required.
In the present invention, a channel is necessary for the formation of oil and gas disasters, in one embodiment, as shown in fig. 5, a schematic diagram of oil and gas conditions of a abandoned oil well with a surface casing and without well-sealing cement in one embodiment of the present invention, the oil and gas content in the abandoned oil well needs to be detected, oil and gas can flow into a working face, and when the oil and gas content exceeds a preset range, the abandoned oil well is marked as an oil and gas disaster well. Both downhole and uphole treatments are required.
In a roof disaster, a waste oil separation well and a exploration well with a sleeve play the role of a 'super anchor rod' or an anchor cable in a stratum, the stratum near the waste oil separation well and the exploration well can be reinforced, the roof near the waste oil separation well and the exploration well can not collapse, so that a large-area suspended roof is formed, the roof can collapse in a large range at a time, toxic and harmful gas in a goaf is forced into a working face or storm wind is generated to damage working face equipment and personnel, a well wall collapses or a shallow sediment fills a shaft, the shaft contains water, gas and oil, and when the working face passes through, if the working face is not treated, the oil separation well and the exploration well can collapse into the working face to cause the disaster.
The invention classifies oil and gas wells according to possible disaster conditions. According to the most dangerous situation, the wells are classified into four types according to the structure of the well and the cement plugging condition, namely, the first type oil well, the second type oil well, the third type oil well and the rest of the wells without treating the oil well are used as the fourth type oil well.
In one embodiment, as shown in fig. 6, a schematic diagram of water and oil gas conditions of a abandoned oil well without surface casing and without well plugging cement according to an embodiment of the present invention, aquifer water easily seeps down along the oil well, the water head height is high, the water hazard is great, the oil well contains water, oil and gas, and the water, oil and gas may gush out when exposed, causing personal injury, wherein the water is downward, the oil gas is upward, and the casing is not in the oil well, the top plate is easy to collapse, and the normal production is greatly influenced. Thus, oil wells belonging to the first category require downhole and uphole remediation.
In one embodiment, as shown in fig. 7, a schematic diagram of the water and roof conditions of a abandoned well with surface casing and well-plugging cement is shown, the well structure is that the well head has the plugging cement, the metal casing is arranged below the well head, the height is generally above the coal-based formation, and water possibly contained in the well can gush out when being exposed, thereby causing personal injury. After the working face is pushed, the top plate is easy to hang to the top in a large area, and potential hazards of disaster of the top plate can be left. Therefore, wells belonging to the second category require downhole and uphole treatments.
In one embodiment, as shown in FIG. 8, a schematic diagram of the water and roof conditions of a abandoned well with surface casing, cemented cement, and well-plugging cement of an embodiment of the present invention, with casing, well-plugging cement, possibly containing water, may be gushed out at the time of exposure, causing personal injury. After the working face is pushed, the top plate is easy to hang to the top in a large area, and potential hazards of disaster of the top plate can be left. Therefore, wells belonging to the second category require downhole and uphole treatments.
In one embodiment, as shown in FIG. 9, a schematic of the water and roof conditions of a abandoned well without a surface casing, cemented cement, and with a seal cement, according to one embodiment of the invention, the cement fills the entire space, except that a roof hazard may remain. Therefore, it belongs to the third category of oil wells and requires downhole remediation.
In one embodiment, as shown in fig. 10, a schematic diagram of water and roof conditions of a abandoned oil well without surface casing and without well plugging cement according to an embodiment of the present invention, there is a risk of collapse, a mixture of yellow mud, water, gas, oil, etc. exists in the well to fill the whole space, the collapse causes weak lithology near the well bore, after the well bore is exposed at the working face, roof fall may occur nearby, and yellow mud, etc. in the well bore may be broken into the working face. Thus, oil wells belonging to the first category require downhole and uphole remediation.
For the fourth type, the oil well is not needed to be managed, the well depth of the oil well is far away from the buried depth of the coal mining layer, the oil well is not communicated with a deep oil-bearing layer, water, oil and gas in the oil well cannot enter the coal mining layer, the influence on normal production and mining is small, the mining working face only needs to observe the oil leakage and gas detection conditions when passing through the oil well, and if the oil leakage or the gas standard exceeding condition is serious, the reason is found out in time and is processed.
Fig. 11 is a flow chart of the aboveground treatment of the abandoned oil well in the coal production area according to one embodiment of the present invention. As shown in fig. 11, the procedure is as follows.
(1) Through hole, well washing
The through holes are mainly used for removing sundries in the sleeve and checking whether the sleeve is deformed and the well depth is qualified; the key point in well flushing is to keep the wellbore clean in preparation for the next procedure.
(2) Logging well
The well logging mainly detects the well cementation quality, the casing fracture condition, the well depth, the oil and gas content in the well, the pressure and the like, and adopts the well logging methods of sound wave time difference, natural potential, natural gamma and the like to detect whether dangerous factors influencing the safety pushing of the fully mechanized coal face exist in the abandoned well or not so as to provide reliable basis for formulating an effective plugging scheme. Logging mainly uses a well shaft as a center to check an underground technical condition packet and the like in a circular range with the radius of 25 cm.
(3) Sleeve plugging
And (4) penetrating holes to exceed the deepest coal seam by 100m, and manufacturing an artificial well bottom at the position to prepare for plugging cement paste. And then plugging the whole well casing by using cement slurry, injecting oil well cement slurry with the density of more than or equal to 2kg/L into the whole well casing, stopping grouting when the height of the cement slurry is 15-20m away from the well mouth, and waiting for setting.
(4) Pressure seal check
After cement slurry is subjected to setting in a shaft for 72 hours, a well mouth is installed, a cement truck is used for pressure test, the plugging effect is verified, the pressure is applied to be 15Mpa, the pressure is reduced within 30 minutes and is not more than 0.5Mpa, if the pressure is reduced to be more than 0.5Mpa, low-viscosity high-strength gel plugging materials are injected, and after the setting is carried out for 24 hours, the pressure is tested again until the pressure is not reduced.
(5) Well head plugging
And (3) pouring cement paste within 15-20m from the wellhead and returning the cement paste to the wellhead, and driving cement piers of 0.5m multiplied by 0.5m above the wellhead.
(6) Wellsite recovery
The landform and the environment of the well site are recovered, the slurry in the sewage disposal pit is completely transported away, the sewage disposal pit is backfilled, the rest of garbage and the like generated by construction are treated, and the recovered well site is subjected to combined acceptance of mine, local villagers and village cadres.
(7) Special case handling
The condition in the hole is simple, and the construction process is selected to carry out oil well plugging treatment according to specific conditions; if the conditions in the holes are special (such as metal residues in the holes) in the process of hole penetration, the complexity in the holes is determined by investigation and technical means, special construction organization design is made, and special condition treatment is carried out.
In one embodiment of the present invention,
the downhole processing comprises:
(1) determining the position of an oil well by drilling a borehole
The working face reveals that the oil well adopts the mode of drilling and exploring the hole, confirms the specific position of oil well step by step.
1. When the distance between the petroleum well and the recovery working face is 20m, the working face is suspended for recovery, and 3 holes are drilled on the coal wall by a ZDK155 drilling machine, wherein the drilling depth is 30m, and the distance is 10 m;
2. when the working face is mined to 10m away from the oil well, a ZDK155 drilling machine is used for drilling 9 20m drill holes on the coal wall, and the distance is 2.5 m;
3. when the working face is mined to be 5m away from the oil well, 17 holes with the distance of 15m are drilled on the coal wall by a ZDK155 drilling machine, and the distance is 1.25 m;
4. when the distance is 2m from the working surface, 33 drill holes with the distance of 0.625m are drilled on the coal wall with the distance of 2m by a pneumatic drill; the operation is circulated according to the program until the stope face passes through the oil well by 10 m. The drill hole position is always perpendicular to the coal wall, as shown in fig. 3:
5. if any one of the drill holes is detected to the position of the oil well in the process of the exploration hole construction, the exploration holes with the construction interval of 300mm are encrypted in the local range near the exploration hole to determine the specific position of the oil well, and then the exploration roadway is constructed to expose the oil well.
(2) Cutting oil well casing
And cutting the sleeve after finding the position of the oil well, wherein the cutting sleeve can adopt tools such as a ball mill and the like, the cutting position of the oil pipe at the top plate is 200mm higher than that of the top plate, the cutting position of the oil pipe is 200mm lower than that of the bottom plate, deep pits with the side length not less than 1000mm multiplied by 1000mm and the depth not less than 1000mm are dug around the oil well, and finally, concrete pouring and plugging are carried out. The gas harm caused by overhigh temperature and spark generation is prevented in the cutting process. Cutting is carried out along the top plate and the bottom plate at a certain distance (after the bottom plate is blocked by cement, the ground is leveled).
(4) If there is a channel to block
The shutoff of 60m upwards is carried out to the oil gas well after the cutting is accomplished, prevents that the water of aquifer and the oil gas in coal-bearing stratum from getting into the working face, and the shutoff is carried out with cement downwards, prevents that the oil gas of lower part from gushing into the working face.
China has a plurality of coal and oil and gas resource overlapping areas, such as Shanxi sublevel mining areas, Shanxi Nengmen mining areas, Ningdong mining areas and the like. The problem of safe and efficient coordinated development of coal resources and resources in the overlapped region of oil and gas resources in the mining areas is a great problem with universality, and the problem of safe and efficient high-resource-recovery-rate exploitation of the coal resources in the affected region of the waste oil well is increasingly highlighted. The treatment method has important significance and practical application value for safe and efficient production of similar mines in China.
Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to the above-described embodiments and application fields, and the above-described embodiments are illustrative, instructive, and not restrictive. Those skilled in the art, having the benefit of this disclosure, may effect numerous modifications thereto without departing from the scope of the invention as defined by the appended claims.
Claims (8)
1. A waste oil well treatment method for a coal mining area comprises the following steps:
detecting whether a waste oil well in a coal mining area is provided with well sealing cement and a surface casing;
when the abandoned oil well has no sealing cement and no surface casing, detecting whether a cavity communicated with an aquifer exists at a position higher than a coal seam in the abandoned oil well and detecting the content of oil gas in the abandoned oil well; when the abandoned oil well has no sealing cement and surface casing, detecting whether a cavity communicated with an aquifer exists at a position higher than a coal seam outside the surface casing of the abandoned oil well or not and detecting the content of oil gas in the abandoned oil well, when the abandoned oil well has the sealing cement and no surface casing, detecting the structural strength of a top plate of a coal face, and when the structural strength of the top plate of the coal face is smaller than a structural strength threshold value, performing underground treatment, wherein the underground treatment comprises the following steps of drilling and detecting holes, and when the oil well is exposed on the coal face, the drilling and detecting holes gradually determine the position of the oil well; cutting the surface casing of the oil well; after cutting, plugging the abandoned oil well 60m upwards, and plugging the abandoned oil well downwards by using cement; when the waste oil well is provided with well sealing cement and a surface casing, detecting whether a cavity communicated with an aquifer exists at a position higher than a coal seam outside the surface casing of the waste oil well;
if the cavity and/or the oil gas content exceeds the preset range, performing the aboveground treatment and the underground treatment, wherein the aboveground treatment comprises the following steps,
washing the well through the through hole, wherein the through hole comprises the steps of removing impurities in the surface casing, detecting the deformation degree of the surface casing and measuring the well depth, and washing the well to keep the well clean;
logging, wherein the well cementation quality, the integrity of a surface casing, the well depth, the oil and gas content in the well and the pressure of the oil and gas content are detected, the logging is carried out by adopting a sound wave time difference method, a natural potential method or a natural gamma method, and the logging is detected in a circular range with the radius of 25cm by taking a well axis as a center;
plugging a surface casing pipe, wherein the through holes are formed until the height exceeds 100m of a coal seam so as to manufacture an artificial well bottom, plugging a full well barrel by using cement slurry, injecting oil well cement slurry with the density of more than 2kg/L into the full well barrel, stopping grouting when the height of the cement slurry is 15-20m away from a well mouth, and waiting for setting;
pressurizing and checking the seal, after cement paste is subjected to waiting for setting in a shaft for 72 hours, pressurizing by a cement truck for 15Mpa, judging that the pressure is qualified if the pressure is reduced by no more than 0.5Mpa within 30 minutes, injecting a low-viscosity high-strength gel plugging material if the pressure is reduced by no more than 0.5Mpa, and checking the pressure again after waiting for setting for 24 hours until the pressure is not reduced;
plugging the well mouth, pouring cement slurry within 15-20m from the well mouth and returning the cement slurry to the well mouth, and drilling cement piers of 0.5m multiplied by 0.5m above the well mouth.
2. The method of treating a abandoned oil well in a coal mining area according to claim 1, wherein: in the drilling exploration, when the abandoned oil well is 20m away from the coal face, the mining of the face is suspended, and 3 drilling holes are drilled on the coal wall by a drilling machine, wherein the drilling holes have the depth of 30m and the distance of 10 m; when the working face is mined to 10m away from the waste oil well, drilling 9 20m drill holes with the distance of 2.5m on the coal wall by using a drilling machine; when the working face is mined to be 5m away from the waste oil well, 17 15m drill holes are drilled on the coal wall by a drilling machine, and the distance is 1.25 m; when the working face is mined to a distance of 2m from the waste oil well, 33 drill holes with the distance of 0.625m are drilled on the coal wall by a pneumatic drilling machine, wherein the drill holes with the distance of 2m are drilled on the coal wall; the drilling position is always vertical to the coal wall, when the drilling hole probes the position of the abandoned oil well, the specific position of the oil well is determined by encrypting the probing holes with the construction interval of 300mm near the probing holes, and then the abandoned oil well is exposed by constructing the probing roadway.
3. The method of treating a abandoned oil well in a coal mining area according to claim 1, wherein: the surface casing of the oil well is cut by a ball mill, the cutting position of a surface oil pipe is 200mm higher than the top plate of the working face and 200mm lower than the bottom plate of the working face, and a deep pit with the side length not less than 1000mm multiplied by 1000mm and the depth not less than 1000mm is dug around the abandoned oil well.
4. The method of treating a abandoned oil well in a coal mining area according to claim 1, wherein: and a gas concentration sensor for measuring methane, ethane, butane, pentane, carbon dioxide, carbon monoxide and/or hydrogen sulfide gas is arranged in the abandoned oil well.
5. The method of treating a abandoned oil well in a coal mining area according to claim 1, wherein: and a stress sensor is arranged on a top plate of the coal face, and a humidity sensor for measuring the water vapor content is arranged in the abandoned oil well and/or outside the surface sleeve.
6. The method of treating a abandoned oil well in a coal mining area according to claim 1, wherein: the abandoned oil well includes a processor that sends an alert based on moisture content, oil and gas content, and/or coal face roof strength.
7. The method of treating a waste oil well in a coal mining area according to claim 6, wherein: the processor comprises a general processor, a digital signal processor, an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), an analog circuit or a digital circuit.
8. The method of treating a waste oil well in a coal mining area according to claim 6, wherein: the processor is provided with a memory comprising one or more of a read only memory ROM, a random access memory RAM, a flash memory or an electrically erasable programmable read only memory EEPROM.
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| CN109372465A (en) * | 2018-09-29 | 2019-02-22 | 中国石化江汉油田分公司江汉采油厂 | A kind of method for blocking for empty well cylinder abandoned well |
| CN109653726B (en) * | 2018-12-27 | 2022-10-28 | 中国地方煤矿有限公司 | Method for detecting damage of oil-gas well in coal mining area |
| CN111236874B (en) * | 2020-03-31 | 2022-07-22 | 应急管理部信息研究院 | Method for cutting ground coal bed gas well casing pipe underground |
| CN113914814A (en) * | 2020-07-09 | 2022-01-11 | 中国石油化工股份有限公司 | Anti-collapse sand consolidation drilling and grinding treatment method for ultra-deep open hole well |
| CN112150006A (en) * | 2020-09-23 | 2020-12-29 | 中煤科工集团重庆研究院有限公司 | Method for treating hydrogen sulfide in grading manner in coal face waste oil well affected area |
| CN112145146A (en) * | 2020-10-15 | 2020-12-29 | 西安科技大学 | Method for exploring inclined columnar danger source in kerosene overlapping area |
| CN112780259B (en) * | 2021-01-06 | 2022-08-02 | 中海油田服务股份有限公司 | Method and device for determining well cementation quality and storage medium |
| CN112709565B (en) * | 2021-01-27 | 2022-07-29 | 国家能源集团宁夏煤业有限责任公司双马煤矿 | Method for determining plugging depth of waste petroleum well in coal mining area |
| CN114293951A (en) * | 2021-12-31 | 2022-04-08 | 国家能源集团宁夏煤业有限责任公司 | Method for plugging waste oil well |
| CN115627786B (en) * | 2022-12-07 | 2023-03-28 | 中国冶金地质总局第三地质勘查院 | Method for plugging waste water taking well |
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