Method for sealing degassing wells

FIELD: mining.

SUBSTANCE: method for sealing degassing wells comprises performing oriented hydraulic fracturing of rocks, creating air-impermeable screens in surrounding array, creating rock layer preventing air filtration into the working part of the degassing well. The rock layer preventing air filtration into the working part of the degassing well is formed between two parallel air-impermeable screens due to impregnation of rocks with liquid with formation pressure higher than air pressure in the mine working.

EFFECT: reduced air inflow from the mine working into the working part of degassing well through coal-rock mass.

10 cl, 1 dwg

 



 

Same patents:

FIELD: mining operations.

SUBSTANCE: invention relates to the coal industry and can be used in the preparation of coalmine methane for recovery by different consumers. A unit for the preparation of coalmine methane for recovery is proposed, containing a moist separator, a filter of wet cleaning the gas, the control devices of methane content in the gas mixture and pressure, a mixer, a devices of protection against emergency regimes, the pipelines of supplying the gas mixture and the captured gas and the control system of methane concentration with the gas analyser and the gas concentration controller, the primary damping container mounted in the supply line of the captured gas in front of the mixer, and the secondary damping container mounted downstream of the mixer in the supply line to the consumer of the gas mixture, the inlet pipeline with an air inlet, a gas analyser connected to the gas concentration controller, an odorator connected to the mixer and the gas concentration controller by the regulating valve, a pressure regulator-stabiliser, and the additional control valves, and a shut-off valve mounted on the inlet pipeline between the air inlet and the mixer. In addition, the unit is provided with a cassette with the separation membranes mounted between the injection and the discharge pipelines, and has the ventilation device connected to the gas pipeline for methane-air mixture intake from the shaft, at that the moist separator, the filter of wet cleaning the gas are mounted in front of the cassette with the separating membranes.

EFFECT: increasing the efficiency of operating unit of the preparation of coalmine methane for recovery, by providing the ability of preliminary separation of recyclable captured methane-air mixtures, and improvement of safety of the unit operation.

1 dwg

FIELD: mining.

SUBSTANCE: invention relates to mining industry and can be used for mining. The method of methane capture during mining of coal layers by a power mining complex comprises the mining of a coal layer using the sections of a powered roof support with box-shaped top covers of a face conveyor and combine. Simultaneously with coal extraction, transportation through a face and preparatory developments, through the holes in the box-shaped top covers and telescopic branch pipes methane is pumped out. From a production face all box-shaped top covers of sections are joined among themselves with corrugated branch pipes of a certain length equal to an advance increment of the powered roof support.

EFFECT: invention allows to implement the comprehensive and rational coal use in subsoil due to efficient by-product extraction of methane, reduce net cost of coal, provide safe mineral development.

3 dwg

FIELD: mining.

SUBSTANCE: method of determining the gas recovery of the mined seam in the stopping face is proposed, which consists in measuring the volumes of coal extracted by the miner and the intensity of methane release in the face area of the stopping face, determining the connection between the measured values and determining the value of gas recovery of the seam in the stopping face of the stopping face. At that the volume of coal excavated, and the intensity of methane release are measured at the site of the seam outside the area of its natural degassing with the mounting chamber and up to the first placing the main roof. The data of volume of coal excavated, which excess their average values during the observation period are used. The value of gas recovery of the seam in the stopping face is determined by the value of the coefficient of the amount of coal excavated in identified relationship between the values measured in the process of combine operation on coal drawing.

EFFECT: improvement of accuracy of determining the gas recovery of the mined seam.

FIELD: mining.

SUBSTANCE: method of extraction of methane during abandonment of methane saturated mine comprising the termination of coal mining in a working face, isolation of local sections, execution and sealing of wellheads, connection of wells to a vent pipeline and methane extraction is offered. The wells are made from mining near break-down chamber over coal block into free space of the broken-down rocks of the main roof of the stopped working face, wells connect to the main vent pipeline and methane extract before isolation of local developments and after isolation of mine.

EFFECT: increase of time of operation of vent wells and increase of volumes of extracted methane suitable for utilisation.

FIELD: mining.

SUBSTANCE: method of stimulation of coal bed through the wells drilled from excavations, comprising the hydraulic fracturing and the subsequent development of the formed cracks by air purge is offered. The hydraulic fracturing is performed by isolation with packers of the well site with the subsequent portion water pumping into the isolated site at a speed and under pressure, sufficient for layer hydraulic fracturing. The pumping of water portions is repeated until occurrence of initial cracks of hydraulic fracturing. Then the water is pumped out from a well and air at the volume sufficient for development of pattern of cracks of hydraulic fracturing is pumped. The creation of pattern of cracks of hydraulic fracturing is repeated on well sites along the whole its length with the intervals pre-determined by geological conditions and pre-set degassing level.

EFFECT: improvement of efficiency of coal bed degassing.

1 dwg

FIELD: mining.

SUBSTANCE: method of determining the length of bearing pressure zone from breakage face is proposed, comprising preparatory workings, mining of coalbed with breakage face, drilling the degasification well, sealing its mouth from the mine atmosphere, measuring the intensity of gas release from the well when it transition from the zone of natural permeability of the bed in the bearing pressure zone from the breakage face. At that, the well in the unrelieved mass of the bed is drilled to the border of the bearing pressure from the opposite working, and the well mouth is sealed to the depth of the bearing pressure zone from the working, from which it is drilled. And the length of the bearing pressure zone from the breakage face is determined according to the distance between the zones of start of loading the bed and start of its discharge from the rock pressure.

EFFECT: improvement of accuracy of determining the length of the bearing pressure zone from the breakage face.

FIELD: mining.

SUBSTANCE: invention proposes a forecasting method of gas balance of a working face, which involves measurement of volumes of extracted coal and intensity of gas release, establishment of a relationship between measured values and determination of a parameter of gas recovery of the bed being developed. The above measurements are made during each coal extraction shift, and the gas recovery parameter of the bed is determined as per intensity of maximum gas release during breaking cycles of the measured coal. A share of gas balance of the developed bed to the bottom-hole region is set by the ratio of intensity of maximum gas release from the bed and intensity of gas release of the working face.

EFFECT: method allows improving reliability of forecast of gas release from gas release sources to the bottom-hole region of the working face and recommending reasonable degassing methods and parameters of the developed bed and the worked-out space, thus providing standard parameters of mine air in a long working face and in an extraction area.

FIELD: mining.

SUBSTANCE: invention relates to mining industry, namely to underground coal extraction. The invention proposes a complex method of preliminary degassing of a working coal bed, a worked-out area and accompanying beds and controlled caving of heavy roof, which involves performance of field development workings - strike entries and cross-entries; then, out of degassing-torpedo in-bed workings there drilled are groups of wells into soil and roof of the bed, and out of the leading in-bed working there drilled are long wells that are directed towards the worked-out area; after that, the leading shooting is performed to create fractures, and smooth roof caving is performed. A set of activities includes location of groups of wells that are common both for degassing and for shooting, and when field development strike entries are being developed, safety stiff and flexible pillars are formed. The wells drilled in the bed roof are of a degassing-torpedo type and they are located in such an order at which formation of fractures is provided by means of the leading shooting for longitudinal caving along the line passing parallel to a longwall. In addition to the leading shooting, lagging shooting is performed, by means of which transverse caving of slabs is performed along the line perpendicular to the longwall. And degassing of the worked-out area before caving in its upper part is performed through half-retained longwalls of the well.

EFFECT: increase of operating safety in a working face in beds that are dangerous as to a gas factor.

6 dwg

FIELD: mining.

SUBSTANCE: proposed method comprises creation of fractures in coal seam by cyclic increase and decrease in fluid pressure in well and affecting the seam by low-frequency high-amplitude pressure pulses at fluid pressure increase in the well. Note here that connection of wellhead via fast-response valve with pressurized water source and with drain valve. Said fast-response valve is opened for time interval sufficient for water wave to reach the most remote section of the well and to develop hydraulic shock so that forming fractures of coal seam are developed. Then, said valve is closed to decrease water pressure to initial value. Note here that duration of valve opening and frequency of hydraulic shock repetition are selected to allow sufficient fracture formation, coal formation destruction and filling of the most remote well section with fragments of destructed coal seam. Hydraulic shocks are repeated unless well is filled with said fragments to its wellhead.

EFFECT: development of uniform system of fractures, accelerated destruction of coal seams at minimum application of equipment.

1 dwg

FIELD: mining.

SUBSTANCE: proposed method comprises drilling of degassing well on the seam, making of permeability channels around said well, water removal and methane extraction. At seam degassing, well mouth is periodically closed and opened. Note here that closure is performed for 1-3 days while opening duration is limited by time required for attainment of maximum methane yield in previous period. Besides, air is forced in degassing wells at zero yield before first closure at absolute pressure over 6 bar to develop starting channels of permeability.

EFFECT: ten-fifteen times increase in methane yield, intensified degassing and reduced gas content.

2 cl, 3 dwg

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil and gas production industry, namely to well-workover operations. The procedure for elimination of behind-the-casing flows includes, before running in of the casing string, performance of geophysical investigations with identification of intervals for potential behind-the-casing flows, equipment of the casing string with pipe expandable up to 24% by outside sealing components, which are placed opposite the intervals of potential flows upon running in of the casing string. When behind-the-casing flows occur and affect inner surface of the expandable pipes equipped with sealing components, they expand the above pipes within the whole range of flows thus sealing borehole annulus and preventing fluid cross-flow from one stratum to another. In order to improve quality expanded pipes are used with sealing components swellable under action of stratum fluids.

EFFECT: suggested procedure allows elimination of behind-the-casing flows in proper way with maintenance of the casing integrity, reduction of material costs and speed-up of the well-workover process.

2 dwg

FIELD: oil and gas industry.

SUBSTANCE: group of inventions is related to elastomers, and namely to reinforced elastomers. The well sealing technique for the well borehole includes receipt of a basic polymer and reinforcing active filler, which contains a matrix of discreet parts of the first material paced in the basic polymer. At the first stage the well sealing is unfolded in the well borehole. Impact is made on fluid sealing in the well borehole, at that transfer of the sealing to the second stage is made under action of the fluid in the borehole. At that discreet part of the first material differ between themselves and/or with the basic polymer by weaker values before impact of the borehole fluid than after impact. At that the first stage is differentiated by the first elastic modulus and the second stage is differentiated by the second elastic modulus, and the second modulus is bigger than the first one.

EFFECT: improving the sealing efficiency.

25 cl, 14 dwg, 2 ex, 4 tbl

FIELD: oil and gas industry.

SUBSTANCE: invention is referred to the area of well-workover operations and can be used for drilling in sludge underflow, cleaning of cavern and installing of a cement plug. The device contains a hollow barrel 1 with though radial holes 2 and outside collar 3, upper and lower sleeves 4, 5 installed with formation of tilted annular slit 6 between their upper and lower surfaces respectively. The lower sleeve 5 can move along the axis of the hollow barrel 1. The outside collar 3 of the hollow barrel 1 is formed below through radial holes 2. The lower sleeve 5 in the upper part has an inner groove 7 for the outside collar 3 of the hollow barrel 1 corresponding to the length of its axial movement along the hollow barrel 1. The lower edge of through radial holes 2 of the hollow barrel 1 is placed above the level of the tilted annular slit 6. Inner surfaces of the upper and lower sleeves 4, 5 and the lower surface of the hollow barrel matching them form an annular cavity A connected hydraulically to a cavity of the hollow barrel 1 through radial through holes 2. The device contains the upper and lower crossover shoes 8, 9. The upper crossover shoe 8 is connected from outside to the upper sleeve 4 and from inside to the hollow barrel 1; it has a prolonged bladed centraliser 10. The lower crossover shoe 9 is connected from inside to the hollow barrel 1 and presses the lower sleeve 5 through a rubber resilient element 11 with pressing force calculated as per inequality. In the middle part the lower crossover shoe 9 has an inner collar 12. In the hollow barrel 1 there are located in-series a thrust bush 13, a hollow piston 14 and a spring 15 resting on the collar 12 of the lower crossover shoe 9 with pressing force calculated as per inequality. The hollow piston 14 has a saddle for a setting ball 16; it is installed with tight covering of through radial holes 2 of the hollow barrel 1. The device contains a rock destruction tool 17 connected to the lower crossover shoe 9.

EFFECT: improving quality of cavern cleaning, installing of cement plug, increasing operating reliability and expanding technological capabilities of the device due to potential drilling into sludge underflow, automatic cleaning and centring of the device in regard to the well axis with rated diameter.

1 dwg

FIELD: oil and gas industry.

SUBSTANCE: configuration of a movable connection increases service life of downhole equipment, allows avoiding accidents and complications both during operation of downhole equipment and at its removal from the well. A seal of the movable connection of downhole equipment consists of a sealing rubber ring, and working and protective washers. Working and protective washers are of split type. A groove is made on the stock. Working and protective washers are installed in the groove in a movable manner. The sealing rubber ring is located between working washers. There is a gap between inner diameter of the working washer and diameter of the groove for the sealing rubber ring. The gap is covered with protective washers. There is also a gap between inner diameter of the cylinder and outer diameter of the stock.

EFFECT: application of the proposed invention allows providing tightness of a seal at operation in the medium containing mechanical impurities, corrosive liquids, and preventing seizure of parts of the movable connection and destruction of a sealing rubber ring.

1 cl, 4 dwg

FIELD: oil and gas industry.

SUBSTANCE: method for elimination of leakage in tubing string includes survey of tubing string inside the well with detection of leakage location, installation of sealing device at the ground level which consists of deformed plastic material device with explosive charge and exploding initiator inside it; the device can pass freely inside tubing sting and cover leakage in tubing string. Exploding initiator is connected to trigger pulse conductor which is connected to detonating system at the ground level; thereafter sealing device is equipped with load, pattern and flow metre interconnected in-series, sealing device is run-in inside tubing string with load, pattern and flow metre and placed at leakage location point. Running-in is made at logging cable; then explosion of sealing device is made with further sealing of tubing leakage by means of its filling and fixation with plastic material; polymer sealing compound hardened in result of plastic deformation and detonation is used as deformed plastic material.

EFFECT: invention allows increasing efficiency and reliability of tubing string repair.

2 cl, 1 dwg

FIELD: oil and gas industry.

SUBSTANCE: when implementing the method, a shutter is lowered to a troublesome zone, shaped sections of the shutter are expanded by creating hydraulic pressure in it and calibrated by means of sections of the expanding head, which are made in the form of puncheons, in a downward direction by pushing through the shutter with the weight of a pipe string, and with a hydraulic jack in the sections requiring additional forces. Besides, prior to lowering, one or more hinge assemblies are installed between the sections, and pressure drop in the hydraulic jack and the last puncheon in relation to the shutter is created due to nozzles. At that, force of the hydraulic jack fixation relative to the well is created with the weight of the pipe string or due to friction of those pipes on the well walls. The device includes a shaped shutter, sections of the expanding head, and a hydraulic jack with a central channel, which is connected to upper end of the shutter. Nozzles are installed inside the expanding head, and one or more hinge assemblies are arranged between its sections.

EFFECT: avoiding the probability of tool sticking owing to shortening the length and application of hinge assemblies increasing the tool flexibility, and allowing to reduce time expenditures when isolating the well troublesome zones.

2 cl, 4 dwg

FIELD: oil and gas industry.

SUBSTANCE: submersible elements made from the material having density that is higher than oil density is transported directly to the operating part of the well till a plug appears in the working face. Only balls from solid mineral or metal, which are made from the same material of elongated rotation bodies of streamlined shape with an offset centre of gravity along the axis, are transported. Diameter of balls and diameter of midlength section of elongated rotation bodies is chosen from minimum value that is determined as per solution of the specified mathematical expression and is less than maximum value that is determined from the solution of the specified mathematical expression. The process is performed till the well is fully filled, or till the acceptable flow rate is achieved.

EFFECT: decrease of flow rate of emergency flowing wells.

5 cl, 2 dwg

FIELD: oil and gas industry.

SUBSTANCE: design of low-angle and horizontal wells includes a technical string, an operating string and a lift string. The operating string is cemented above the productive formation roof. The operating string in the productive formation is divided into sections with casing packers, and sections include filter sections and sections of solid pipes. The lift string in the productive formation is equipped with operating packers, installed inside the sections of solid pipes of the operating string and groups of controlled valves equipped with calibrated inlet side holes arranged inside filter sections. A seat nipple is installed at the end of the lift string. Controlled valves and the nipple are made as capable of interaction with control devices lowered inside a lift string.

EFFECT: possibility to control an inflow from isolated sections of a low-angle or horizontal well shaft or their total selective water isolation.

3 dwg

FIELD: oil and gas industry.

SUBSTANCE: well is filled with liquid nitrogen, tubing string is removed from the well and there performed is the control for freezing rocks and fluids adjacent to the well. After formation of shut-off plug in well and fluid fountain blocking the cement grouping is pumped into the zone above the well and pressure in well is maintained till its hardening.

EFFECT: elimination of emergency situations at fields.

3 dwg

FIELD: oil-and-gas industry.

SUBSTANCE: set of inventions relates to sealing of borehole perforation and composition used to this end. Proposed method comprises adding bridging material to make plugs in clearances so that fluid leaks are limited or eliminated. Bridging material is preferably degradable or soluble plastic fibers, insignificantly larger than said clearances. If necessary, said particles may be nondegradable, stiff fibers of various shape and smaller than clearances but able to close them. Mixes of bridging materials may well be used. Bridging material may be added to sealing balls, fitted thereafter, or in both versions.

EFFECT: eliminated leaks between balls and perforations.

18 cl, 2 dwg

FIELD: mining industry, namely means to seal or pack boreholes or wells, particularly for constructing water wells and for consolidating water-supply well intervals with tail casing pipes under primary casing pipes.

SUBSTANCE: device has tail casing pipe head and gripper system of primary casing pipe, packing members, circlips and sub. Upper part of outer head surface is cylindrical and has left-handed thread. Lower part thereof facing well bottom is conical. Intersection point of conical surface generators lays on well axis. Gripper system of primary casing pipe is formed as a shoe having inner surface defined by two conical surfaces with apexes extending in opposite directions. Adjoining surfaces of tail casing pipe head and casing shoe have 8-10° cone angles.

EFFECT: simplified structure and improved manufacturability, increased reliability and reduced material consumption.

4 cl, 4 dwg

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