Heat yield-increasing technique in coal bed gas well undergroundTechnical field
The present invention relates to coal bed gas well mining technology field, specially a kind of coal bed gas well underground heating volume increase workSkill.
Background technique
China is one of coal bed gas resource country the most abundant.The exploitation of coal bed gas is not only to China's energy safeguard and coalMine is of great significance safely, and to energy resource structure is improved, clean energy resource development is promoted also to be of great significance.But from coal seamFrom the point of view of gas industry development status, methane output and utilization long-run development are slow, do not go out to obtain essence by years developmentRaising.The fundamental factor developed slowly be the geological conditions of China's complexity cause the production technique difficulty of coal bed gas compared withGreatly, it is directed to the research theory achievement of forefathers, proposes a kind of method for increasing yield of coal bed gas with strong applicability.Specifically by straightIt connects and is heated in coal bed gas well underground to change the temperature field of coal seam reservoirs and increase the yield-increasing technique of methane output.
Summary of the invention
The purpose of the invention patent is: proposing a kind of coal bed gas well underground on the basis of existing theory only supportsYield-increasing technique is heated, which can realize the volume increase of coal bed gas well head.
The present invention adopts the following technical scheme that;
A kind of coal bed gas well underground heating yield-increasing technique, is by the tripping in the annular space of existing coal bed gas well oil pipe and casingThe structure that one bottom is high temperature resistant glass fibre reinforced plastic screen casing, top is annular space steel pipe composition, the annular space steel pipe and wellhead sealing on topConnection, is high temperature-resistant cable in annular space steel pipe, is heating rod, high temperature-resistant cable and heating rod in high temperature resistant glass fibre reinforced plastic screen casingConnecting part is to be tightly connected；Heating rod directly realizes heating to the water at coal bed gas well bottom after being powered, and the water in coal seam will gradually addAround the heat diffusion that hot pin releases to shaft bottom coal seam, accelerate the coal bed gas parsing in coal seam reservoirs.
The annular space steel pipe will be more than hydrodynamic face, and the interface of high temperature resistant glass fibre reinforced plastic screen casing and annular space steel pipe will be placed in hydrodynamicIt is more than face.
The interface of the high temperature-resistant cable and heating rod will be placed in hydrodynamic face or more.
It can reach following effect through the invention: bottom hole temperature (BHT) field changed by the heating directly to coal seam reservoirs；Improve coalThe recovery ratio of layer gas；Accelerate the extraction of coal bed gas in coal seam；Shaft bottom water temperature increases the Brownian movement for increasing coal dust, improves indirectlyCoal dust accumulates holddown well workover problem.The assembling of complete equipment device is simple, and technological operation is simple, has practical operability.EspeciallyIt is the coal bed gas well that will affect suitable for down-hole mining.The assembling of complete equipment device is simple, and technological operation is simple, has and actually may be usedOperability.
Detailed description of the invention
Heat yield-increasing technique schematic diagram in Fig. 1 coal bed gas well shaft bottom；
In figure: polished rod (1), outlet pipeline (2), outlet pipe (3), cementing concrete (4), high temperature-resistant cable (5), annular space steel pipe(6), high temperature resistant glass fibre reinforced plastic screen casing (7), heating rod (8), high temperature resistant glass fibre reinforced plastic screen casing underseal (9), coal seam (10), casing (11),Oil pipe (12).
Specific embodiment
This modification scheme is to increase a part of device on the basis of existing coal bed gas well, and specific implementation method is as follows:
According to the annular space steel pipe and high temperature resistant glass fibre reinforced plastic screen casing of coal seam depth and coal seam thickness production corresponding length, in existing coalOne bottom of tripping in is high temperature resistant glass fibre reinforced plastic screen casing in the annular space of layer gas well oil pipe and casing, and top is the knot of annular space steel pipe compositionThe annular space steel pipe of structure, top is connect with wellhead sealing, is high temperature-resistant cable in annular space steel pipe, is heating in glass reinforced plastic screen casingStick, high-temperature cable and heating rod connecting part are to be tightly connected.2, directly the water at coal bed gas well bottom is realized after heating rod is powered and is addedHeat around the heat diffusion to shaft bottom coal seam that the water in coal seam gradually releases heating rod, accelerates the coal bed gas in coal seam reservoirsParsing.
The present invention improves the recovery ratio of coal bed gas, accelerates coal by directly changing bottom hole temperature (BHT) field to the heating of coal seam reservoirsThe extraction of coal bed gas in layer, is the coal bed gas well that will affect especially suitable for down-hole mining, and water temperature raising in shaft bottom increases coal dustBrownian movement, indirectly improve coal dust accumulate holddown well workover problem.The assembling of complete equipment device is simple, and technological operation is simple, toolThere is practical operability.
Although being described above in conjunction with preferred embodiment of the attached drawing to this patent, this patent is not limited toThe specific embodiment stated, the above mentioned embodiment is only schematical, be not it is restrictive, this field it is commonTechnical staff, when not departing from this patent objective and scope of the claimed protection, may be used also under the enlightenment of this patentBy make it is many in the form of, these are belonged within the protection scope of this patent.