煤层气多分支水平井钻井关键技术研究

在分析中国煤层气藏具有低压、低渗、低饱和、构造煤发育以及非均质性强烈等地质特征的基础上，认为在我国用常规垂直井开发煤层气具有很大的地质局限性，进而提出用多分支水平井来提高煤层气单井产量和采出程度。结合沁水盆地6口成功井的实践，剖析了多分支水平井钻井的地质工作重点以及两井连通、井眼轨迹控制、井壁稳定控制技术等关键环节，指出采用多分支水平井开发煤层气是适合中国煤层气藏地质特点的最佳技术选择。

CRITIAL DRILLING TECHNIQUES OF MULTILATERAL HORIZONTAL WELLS USED TO DEVELOP COALBED METHANE RESERVOIRS

Based on the analysis of the geological characteristics of coal bed methane (CBM) reservoirs in China, such as low pressure, low permeability, low saturation, regionally appeared pulverized coal lenses and high heterogeneity, this study concluded herein that to develop CBM reservoir in China with conventional vertical well drilling would be restricted by many geological limitations. In this case of study, multilateral (ML) horizontal well drilling was recommended to increase methane gas production from each well and also improve the gas recovery factor. Combining with the practices of successful six wells drilled in the Qinshui Basin, this study discussed the key procedures of ML horizontal well drilling, including the emphases of geological work, junction of two laterals, well trajectory control and wellbore stability control, etc. This paper points out that ML horizontal well is the best choice for the development of CBM reservoir in China.