煤层气U型井钻井采气技术研究

Study on drilling and extraction technologies for U-shape CBM wells

鲜保安 夏柏如 张义 鲍清英 王海军 刘建伟

XIAN Baoan XIA Bairu ZHANG Yi BAO Qingying WANG Haijun LIU Jianwei

中国地质大学，北京　100083 中国石油勘探开发研究院廊坊分院，河北廊坊　065007 华北油田公司采油工艺研究院，河北任丘　062552

China University of Geosciences, Beijing 100083, China Research Institute of Petroleum Exploration and Development-Langfang, PetroChina, Langfang 065007, China Research Institute of Oil Production Technology, Huabei Oilfield Company, Renqiu 062550, China

国内高陡构造煤层气资源丰富、分布较广，开发潜力巨大。针对高陡构造煤储层特点，提出了一种适合开发高陡构造煤层气的U型井钻完井技术，并结合霍林河盆地低煤阶煤层气地质特征，给出了配套的U型井钻完井技术、欠平衡钻井工艺及地面采气技术。结果表明：U型井钻采技术充分利用了直井和定向井的技术优势，可结合煤储层地质特性，利用流体势能原理实现煤层的排水降压采气；采用充气欠平衡钻井技术，通过合理优化注气排量、注气压力和钻井液排量等，可有效保护煤储层，减少储层污染；采用组合U型井钻采技术，可实现多口U型井共用一口直井进行排采，从而节约地面资源，发挥一井多用的作用。

The high steep structure coal-bed methane（CBM）resources are abundant and widely distributed in high steep structures in China, so there is great potential for development. According to the characteristics of coal seams in high steep structures, a new technology, namely U- shape well drilling and completion technology, is proposed, and it is suitable for developing the CBM in high steep structure. Based on the geologic features of low-rank CBM in Huolinhe Basin, the U-shape well drilling and completion technology, the under-balanced drilling technology, and the surface acquisition technology, etc., are also introduced in details. It comes to conclusion that the U-shape drilling and extraction technology has the advantages of both vertical wells and directional wells, it could implement the dewatering and gas producing with the geologic features and the energy of position, and it could also prevent the coal seams from pollution with the under-balanced drilling technology. By using the combined U-shape drilling technology, gas could be produced from the common vertical well for several U-shape wells, it could save a lot of surface facilities.