煤层气井超短半径自进式水平钻井技术研究

SELF-FEEDING HORIZONTAL DRILLING TECHNOLOGY WITH SUPER-SHORT RADIUS FOR COAL-BED METHANE WELLS

煤层气井超短半径自进式水平钻井技术是在煤层气勘探井内布置机械或水力扩孔装置,对准选定的煤层进行扩孔后下入特制的转向工具在300mm的曲率半径内实现由垂直转向水平进行钻井。自进式钻头由旋转喷嘴、钻屑整合装置、推力提供装置等组成。自进式钻头带动为其提供高压水动力的特制胶管向前连续钻井。高压水通过高压胶管为自进式钻头提供动力进行钻井,推力及排渣。该技术可以在同一煤层气勘探井内,在不同煤层内完成多个径向水平钻孔。这些径向水平钻孔的形成可以沟通新的瓦斯流动通道,提高煤层气产量。

Self-feeding horizontal drilling technology with super-short radius for coal-bed methane wells is to place the mechanical or hydraulic enlarging bit in the exploration well of coal-bed methane, enlarge the hole against the selected coal formation, put down the special steering tool, and fulfill horizontal drilling from vertical drilling within 300 mm of the radius of curvature. The self-feeding bit consists of the rotary nozzle, the cutting conformity device and the power supply device etc. The self-feeding bit carries the special rubber tube that provides high-pressure hydrodynamics for the bit to drill continuously. The high-pressure water passing through the high-pressure rubber tube provides power for the self-feeding bit to drill, penetrate and discharge scum. The technology can make several radial horizontal bores at different coal formations in the same exploration well of coal-bed methane. The radial horizontal bores can connect the new flowing channels of gas to increase the coal-bed methane production.