Multi-layer discharge and mining device for multiple seam developed area

Abstract

The invention discloses a multi-layer discharge and mining device for a multiple seam developed area, which comprises an additional casing, the outer ring of the upper part of the additional casing is provided with a plugging part, the wall of the additional casing on the lower side of the plugging part is provided with a drain hole, the outer ring of the additional casing on the lower side of the drain hole is provided with a first packer, and the additional casing is provided with an elastic cushion for covering the drain hole. The invention aims at the large difference of stratum liquid feed capacity of multiple seam during the multi-layer discharge and mining of a multiple seam developed area, when the existing discharge and mining device is used to discharge and mine, the pressure is difficult to control, which can cause permeability to be sharply reduced so as to result in large reduction on gas production rate, with the multi-layer discharge and mining device for the multiple seam developed area disclosed by the invention, pressure of the multiple seam can be stably reduced, the reasonable and effective multi-layer discharge and mining can be realized, and the goal of stable and continuous of gas production and high yield can be achieved.

Description

technical field [0001] The invention relates to a multi-coal seam combined seam drainage equipment. Background technique [0002] Many coal seams are commonly developed in most areas of our country. In areas where many coal seams develop, only a single layer is used for ground development of CBM, and the investment risk is high. In order to reduce the cost of exploration and development, many coal bed methane companies have adopted Multiple coal seams are all drilled through, and the purpose of joint gas production of multi-layer coal is achieved by draining water in multi-layer coal by using screw pumps, electric submersible pumps or beam pumps. When multi-coal seam drainage is implemented, because they "share" one wellbore, the speed of pressure transmission during drainage and gas production has a great influence on the gas production rate. The movement of proppant, coal powder or proppant will cause the clogging of coal reservoir fracture channels, and the clogging of f...

AI Technical Summary

Problems solved by technology

At present, when multiple layers of coal are combined for drainage, because they "share" the same wellbore, when the current drainage equipment is used for drainage, the dynamic liquid level of the multi-layer coal is the same. When the liquid supply capacity of the multi-layer coal When the difference is obvious, it will inevitably cause the pressure transmission of one layer of coal to be fast, and the pressure of another layer of coal to be transmitted slowly, which may cause the pressure of one layer of coal to be excited, which will greatly affect the gas production effect

Aiming at the fact that the pressure system of multiple coal seams is inconsistent and the fluid supply of the formations is very different, and the current drainage equipment is used for drainage, the coal seam pressure is seriously excited, the coal powder and proppant are frequently moved, and the gas production effect is seriously affected. A pressure system adjustment device for multi-coal seam drainage is the key to improving stability, continuity and high production in such areas.

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