Coal mine underground complex fractured formation nearly-horizontal pressurizing and directional drilling device and method

Abstract

The invention relates to a coal mine underground tunnel drilling method, in particular to a coal mine underground complex fractured formation nearly-horizontal pressurizing and directional drilling device and method. The coal mine underground complex fractured formation nearly-horizontal pressurizing and directional drilling device comprises an orifice sleeve pipe for sealing an orifice during construction, a directional drilling tool assembly penetrating through the orifice sleeve pipe so as to enter a coal bed during construction, and a throttling and pressurizing system connected with a first fluid passageway formed between the directional drilling tool assembly and the orifice sleeve pipe, wherein a drilling tool center hole for one-way conducting is formed in the directional drillingtool assembly; and the throttling and pressurizing system can recover and input a fluid through the first fluid passageway. According to the coal mine underground complex fractured formation nearly-horizontal pressurizing and directional drilling device and method provided by the invention, a high-pressure flushing fluid is provided for a drill hole, and the pressure magnitude of the flushing fluid is controlled, so that a radial additional support force on the hole wall through the flushing fluid is larger than a balance pressure value of the hole wall, the drill hole is ensured to keep stable, the problems that the complex fractured formation drill hole is easy in instable failure and the safety accidents are occurred frequently are solved, and the hole forming rate and the constructionsafety of various coal mine underground nearly horizontal geological exploration and disaster prevention drilling are improved.

Description

technical field [0001] The invention relates to an underground coal mine tunnel drilling method, in particular to a near-horizontal pressurized directional drilling equipment and method for complex and broken formations underground in a coal mine. Background technique [0002] Restricted by my country's energy resource endowment of "rich in coal, poor in oil, and low in gas", coal has long been the main energy source and basic industry in China. [0003] Coal mine underground drilling engineering is an important technical means for coal mine geological exploration, disaster prevention and emergency rescue. It is widely used in the fields of mine gas drainage, water disaster prevention and geological anomaly detection. The annual drilling engineering volume is nearly 1 billion linear meters. Mine safety assurance capabilities have played a positive role. [0004] However, my country’s coal is mainly mined by underground methods, and various types of boreholes in coal mines a...

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Problems solved by technology

[0006] The purpose of the present invention is to provide a near-horizontal pressurization method for complex and broken strata in coal mines in order to solve the technical problems of easy instability and damage of the hole wall, low porosity rate, and high safety risk in the construction of near-horizontal drilling in complex and broken strata in underground coal mines. Directional drilling equipment and method

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