控压钻井技术在页岩气钻探中的应用前景

Application prospect of MPD technology in shale gas drilling

唐守宝 卢倩 宋一磊 李明建 周号博

TANG Shoubao LU Qian SONG Yilei LI Mingjian ZHOU Haobo

神华地质勘查有限责任公司，北京　100011 北京探矿工程研究所，北京　100083 中国石油大学，北京　102249

Shenhua Geological Exploration Co. Ltd., Beijing 100011, China Beijing Institute of Exploration Engineering, Beijing 100083, China China University of Petroleum Beijing, Beijing 102249, China

随着国内页岩气勘探开发进程的不断加大，页岩气钻井过程中遇到的复杂事故也愈发凸显。针对我国南方易漏、岩性构成复杂的页岩地层，为了快速、安全有效地钻穿复杂页岩层段，决定采用控压钻井技术破解页岩气层常见钻井难题。国内南方扬子地区主要发育了2套页岩地层：志留系龙马溪组和寒武系牛蹄塘组，纯页岩段较少、岩性构成复杂且破碎严重。根据页岩气钻井资料，钻井过程中经常钻遇灰质、粉砂质和硅质页岩，溢流和井漏经常并发出现，页岩层发育较厚的目的层段钻井钻井液密度窗口较小，井壁极不稳定。结合页岩地层岩性发育特征、控压钻井技术特点、室内实验分析、现行的控压钻井配套设备等相关因素，可以考虑采用井底常压法控压钻井技术钻穿大段复杂页岩层段。

As the exploration and development of domestic shale gas continue, the complex incidents we encountered during drilling are also increasingly prominent. For the shale formations which is leaky and have complex lithology in South China, MPD is necessary to learn to drill through the complicated shale interval in a fast, safe and efficient manner and to break these common technical challenges of drilling. Currently, southern Yangtze region mainly develops two sets of shale formations, Silurian Longmaxi and Cambrian Niutitang. However, there are less pure shale section, complicated lithology and serious fragmentation. According to the data of shale gas drilling, the limy, silty and siliceous shale is often met during drilling, frequently accompanied with overflow and lost circulation. For the target interval with thickly developed shale bed, the density window of drilling fluid is small and the well wall is extremely unstable. According to the lithologic development of shale bed, technical characteristics of MPD, lab analysis, current MPD supporting equipment and other relevant factors, the MPD in bottom hole constant pressure method can be used to drill through the large and complicated shale interval.