A two-way reciprocating drilling three-stage reaming drilling tool and drilling method for large-caliber well completion in structural coal

Abstract

The invention relates to a tectonic coal large-diameter well completion bidirectional reciprocating type drilling three-level reaming drilling tool which is suitable for underground coal mine. A one-level reaming and a two-level reaming are completed with a plunger drill bit, a three-level reaming is completed with a cutter wing, and the activation of the reaming is adopted with a hydraulic control mode; springs are used for converting a fixed pressure value of the reaming pumping pressure to a pressure range with an appropriate range, and the operability of controlling the reaming pressure can be improved; and a three-level reaming recycling assembly drilling tool inner pipe is composed of an upper section and a lower section which are connected and sealed through an inner pipe connectingseal ring, and the down-moving of a cutter wing blocking mechanism and the cutter-out of the cutter wing can be completed step by step. The drilling reaming with a horizontal well, a vertical well, aslant well and the other modes can be achieved at the tectonic coal and other softer formation, a three-level reciprocating type reaming operation of one of hole segments can be completed according to engineering requirements, and the requirements of the tectonic coal coal-bed gas exploitation and the other engineering activities can be met.

Description

technical field [0001] The invention relates to a three-stage reaming drilling tool and a drilling method, in particular to a three-stage reaming drilling tool for two-way reciprocating drilling of large-diameter wells for structural coal. Background technique [0002] Tectonic coal is widely developed in China and is rich in coalbed methane resources. However, due to the prominent characteristics of gas-rich, low permeability, soft, and broken structural coal, structural coal mining and coalbed methane development are very difficult, which is a recognized problem. Drilling technology can be used as a very important technical method for the development of coalbed methane in structural coal. Drilling in structural coal can form large-diameter boreholes, increase the pressure relief range of coal seams, improve the permeability of coal seams, and increase the desorption rate and efficiency of coalbed methane. With the gradual increase of the depth of coal resource development,...

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Problems solved by technology

[0005] The purpose of the present invention is: aiming at the deficiencies of the above-mentioned technologies, to provide a method to solve the problem of single reaming mode of the current reaming while drilling tool, low reaming series, low reaming rate, and difficulty in forming large-diameter holes. Two-way reciprocating drilling three-stage reaming drilling tool and drilling method for large-diameter well completion of structural coal with high reaming rate

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