Water-jacket type reverse microcirculation guiding coring device

Abstract

The invention relates to a water-jacket type reverse microcirculation guiding coring device. The coring device comprises a drill bit and a clamp spring seat, wherein the clamp spring seat is nested inthe drill bit, a through water tank is arranged on the outer side wall of the clamp spring seat, a drill bit matrix and a drill bit matrix working layer are arranged at one end of the drill bit, direct water injection nozzles and side water injection nozzles communicating with the water tank are arranged on the drill bit matrix and the drill bit matrix working layer, and direct water injection tanks and side water injection tanks are further arranged in the drill bit matrix and the drill bit matrix working layer. According to the coring device, other matching structures of a rope coring drilling tool are integrated and effectively combined, so that a fractured formation can smoothly enter an inner pipe for guiding while drilling fluid is prevented from directly eroding rock cores, the rock core clamping distance is shortened during coring, and therefore, the rock core recovery rate is increased.

Description

technical field [0001] The invention relates to a coring tool for geological drilling, which is mainly aimed at loose and easily eroded formations in structurally broken zones, belongs to the technical field of geological engineering, and is a water-proof micro-reverse circulation guiding coring device. Background technique [0002] In wireline core drilling for geological cores, loose and broken formations are easily eroded and eroded by drilling fluid during drilling, resulting in a decrease in the recovery rate of rock cores and affecting geological prospecting results. Complicated formations with insufficient recovery rate and phenomena during drilling have several common characteristics: [0003] First, most of them are clastic, powdery, muddy and structurally fractured zones, and their common characteristics are formations with loose structure and weak cementation strength; second, the drilled core is easily washed by drilling fluid at the bottom of the drill bit. The...

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Problems solved by technology

[0003] First, most of them are clastic, powdery, muddy and structurally fractured zones, and their common characteristics are formations with loose structure and weak cementation strength; second, the drilled core is easily washed by drilling fluid at the bottom of the drill bit. The third is that the broken core during drilling is easy to form a blockage at the bottom of the spring seat and the inner step of the drill bit, and the blockage will double the time for mechanically breaking the rock layer and core of the hole wall, thereby aggravating the cracking of the core and repeated wear of the drill bit The action time of the rock core is prolonged, which makes the rock core more likely to be eroded; fourth, this type of formation requires drilling fluid with relatively high viscosity and high solid content to protect the wall, and it is easy to cause pump pressure to increase, Induce leakage in the hole, false circulation, reduce drilling speed and other problems

Therefore, insufficient core recovery usually causes a bad cycle of drilling quality and hole wall stability problems

[0004] In response to this problem, for a long time, relevant industry personnel have developed many technical methods to try to solve it, including "308 drilling tools", drill bits with bottom spray structure, jet flow reverse circulation drilling tools, etc., but the actual application effects cannot be effectively solved, especially Aiming at the core drilling method of wireline coring, few people use it in drilling construction

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