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.