Near-horizontal pressurized directional drilling equipment and method for complex fractured formations in underground coal mines

Abstract

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. It includes: an orifice casing, which is used to close the orifice during construction; a directional drilling tool assembly, which passes through the orifice casing to enter the coal seam during construction, and is provided with a unidirectional drill tool center hole; throttling a pressurization system, connected to the first fluid channel formed between the directional drilling tool assembly and the orifice casing, and capable of recovering and inputting fluid from the first fluid channel; the present invention provides High-pressure flushing fluid, and the pressure of the flushing fluid is controlled, so that the radial additional support force of the flushing fluid on the hole wall is greater than the equilibrium pressure value of the hole wall, ensuring the stability of the drilling hole and avoiding the instability and damage of the drilling hole in complex and broken strata, and safety accidents High-incidence problems improve the hole formation rate and construction safety of various near-level geological exploration and disaster prevention drilling in underground coal mines.

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...

AI Technical Summary

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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