樊庄区块煤层气羽状水平井钻井实践

STUDY ON PLUME-LIKE HORIZONTAL WELLS DRILLED IN METHANE COALBEDS IN FANZHUANG BLOCK, QINSHUI, SHANXI PROVINCE

山西沁水盆地樊庄区块的煤层具有埋深适中、厚度大、分布稳定、保存条件好、煤储层物性较好和含气量高等特点,如果利用常规直井开发,从提高裂缝导流能力、减少对煤层的伤害和降低单井钻井成本、扩大单井控制面积、提高单井产量等方面都达不到理想的效果。因此,采用羽状水平井开发是有必要的。通过对山西沁水樊庄区块地质特征的研究,得出了该区块满足羽状水平井钻井技术开发的结论,结合樊庄区块煤层气羽状水平井晋平井组钻井的现场实践研究,提出了煤层气羽状水平井的关键技术(井眼轨道控制技术、洞穴井交汇技术和沿煤层钻井井眼稳定性技术),并对其进行了相应的分析研究,研究成果对利用羽状水平井钻井技术开发煤层气具有一定的实际应用价值。

The coalbeds in Fanzhuang Block, Qinshui, Shanxi Province are characteristic of shallow burial, large thickness, stable distribution, good preservation conditions, good petrophysical performance, and high gas content. The traditional vertical well drilling cannot be used to develop the coalbeds with ideal results in terms of increasing the flow conductivity of fractures, decreasing the damage to the coalbeds formation, reducing the drilling cost of individual wells, expanding the control area of individual wells, and increasing productivity of individual wells. So it's necessary to use plume-like horizontal wells to develop coalbed methane. Based on analysis of the basic geological features of Fanzhuang Block, Qinshui, Shanxi Province, it is found the plume-like horizontal well is fit for this block. After study on plume-like horizontal Jinping wells already drilled in coalbeds of Fanzhuang block, the critical techniques for drilling plume-like horizontal wells in coalbeds are listed and investigated, such as well path control, drilling through cavity section, and wellbore stability. These investigation results can be actually applied in plume-like horizontal well drilling to develop coalbed methane in China.