绒囊钻井液在煤层气水平井稳定井壁技术的应用  

Application of Chorionic Sac Drilling Fluid in Stabilizing Borehole Wall in Horizontal Coal Bed Methane Drilling

作　　者：孟尚志[1,2] 张志珩 赵军[2] 

机构地区：[1]中国地质大学(北京)能源学院 [2]中联煤层气有限责任公司 [3]中国石油大学(北京)石油工程学院

出　　处：《钻井液与完井液》2014年第3期35-38,97-98,共4页Drilling Fluid & Completion Fluid

基　　金：国家科技重大专项"柳林地区煤层气储层伤害控制技术"(2011ZX05062-002)资助

摘　　要：煤层气水平井可以显著提高单井产能,创造更大的经济效益。由于煤岩本身的地质特征和物化特性,煤层气水平井井壁失稳现象时有发生。室内实验优选了绒囊钻井液配方,评价了其流变性、抑制性、润滑性和封堵能力,得出绒囊钻井液具有很好的悬浮能力,可避免形成岩屑床;能够降低黏土矿物水化膨胀的程度,减少钻杆同井壁之间的摩阻和扭矩;也能有效地封堵煤岩割理及裂缝,增大了水平井井壁的承压能力,进而提高水平井井壁的稳定性,减少井漏、垮塌等事故的发生。介绍了该绒囊钻井液在"U"型井和"V"型井水平段的应用情况,应用井段的钻进均很顺利,表明该绒囊钻井液在煤层气水平井上具有很好的应用前景。Borehole instability has always been encountered in horizontal drilling for coal bed methane because of the geological and physical-chemical characteristics of coal bed formations. A drilling fluid treated with chorionic sac was evaluated for its rheology, inhibitive capacity, lubricity and sealing and plugging capacity. It is concluded that the chorionic sac drilling fluid has good suspending capacity which aided in avoiding the formation of cuttings bed. This fluid also reduces the hydration and swelling tendency of clay minerals and mitigates friction and drag between drill string and bore hole wall. Moreover, it effectively seals and plugs fissures and fractures generated in coal bed formations, increasing the pressure bearing of borehole wall in horizontal wells, which in turn improves the stability of borehole wall and minimize the tendency of mud losses and borehole wall collapse. The application of the chorionic sac drilling fluid in the horizontal drilling in a U-type well and a V-type well was successful, showing good prospects in coal bed methane horizontal drilling.

关 键 词：绒囊钻井液 煤层气 水平井 井眼稳定 现场应用 

分 类 号：TE254.3[石油与天然气工程—油气井工程]