Downhole directional hole bedding guided drilling system and method based on formation lithology identification

Abstract

The invention relates to a downhole directional hole bedding guided drilling system and method based on formation lithology identification. The lithology while-drilling identification of a drilling stratum is achieved through a direct parameter comparison method and an orientation radiating rose diagram comparison method according to coal measure stratum lithology while-drilling identification criteria and the stratum natural radiation value, measured by a coal measure stratum physical property parameter while-drilling measurement device in real time, of the near-bit position. By combination with measurement of a drilling track, precise space positioning of a practical drilling track relative to a target stratum is achieved, and bases are provided for controlling a downhole directional hole to do bedding extension in the target stratum in the preset direction; the technical problems that an existing underground coal mine directional drilling technology can only conduct drilling according to the space geometric positioning of the drilling track, cannot distinguish strata and is poor in drilling efficiency and low in target stratum elongation are solved; and through precise bedding directional drilling of the downhole directional hole, an effective means is provided for improving the drilling construction efficiency and the utilization effect, verifying the stratum geological information of a mine lot and ensuring drilling construction safety.

Description

technical field [0001] The invention relates to a drilling system and method, belonging to the field of coal mining, in particular to an underground directional drilling system and method based on formation lithology identification. Background technique [0002] Coal is an important pillar of my country's economic construction, but because my country's coal mines are mainly underground mining, the complex geological conditions of coal fields have brought serious threats to coal mine safety production, and gas disasters are the most serious accident type. [0003] Gas pre-drainage is the most effective technical means to reduce the gas content of coal seams and prevent gas disasters. It is also the basis for comprehensive utilization of gas. It is divided into two modes: ground mining and underground mining. Currently, underground mining is the main method, and mainly through Drill holes for gas pre-extraction. [0004] The depth, diameter and elongation of the target format...

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Problems solved by technology

[0007] The present invention mainly solves the problem that in the prior art, when the downhole directional holes are drilled according to the spatial geometric positioning of the drilling trajectory, the actual drilling trajectory cannot be ensured to be in the target formation due to the unknown undulations of the coal-measure strata in the mine. For the problem of long-distance extension, a system and method for downhole directional hole and bedding-oriented drilling based on formation lithology identification are provided

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