松软低透性薄煤层中水平对穿连通井钻井技术

Drilling Technology of Horizontal-opposing Communicated Well in Soft and Low Permeability Thin Coal Seam

摘要:

乌兰煤矿煤储层具有煤质软、散,钻遇地层倾角大，目的层埋深浅等特点，造成钻井施工中存在井眼轨迹控制难度大、漏失严重、固井困难等问题。针对所遇到的问题，在井身结构设计、设备选择及钻具组合、钻进参数、井眼轨迹控制、钻井液、套管以及固井技术方面采取了有效的技术措施，在松软低透性薄煤层中实现了水平长距离成孔（煤层段中最长穿行距离达到223.73 m），与直井成功对穿连通。通过对乌兰矿煤层气水平对穿井施工工艺的分析，总结了在松软低透性薄煤层中实现水平对穿连通井钻井、成井的施工经验。

Abstract:

Coal reservoir of Wulan mine has the characteristics of soft & loose property, large inclined angle in drilled formation and shallow target bed, well trajectory control is difficult with serious leakage and cementing problem. Effective technical measures were adopted in well structure design, equipment selection, drill assembly, drilling parameter, well trajectory control, drilling fluid, casing and cementing; long-distance horizontal well in thin and soft-low permeability coal seam was realized (with the longest distance of 223.73m), which was successfully connected to the vertical well. Based on the analysis on the construction technology of coal bed methane horizontal opposing well in Wulan mine, the paper summed up the construction experience of horizontal opposing well in thin and soft-low permeability coal seam.