渤中区块井壁稳定机理

The mechanism of borehole stability in Bozhong Block

胡国金 韩雪银 刘峰 陶林 王兴起 宋晓伟

HU Guojin HAN Xueyin LIU Feng TAO Lin WANG Xingqi SONG Xiaowei

中海油能源发展股份有限公司工程技术分公司 中海石油(中国)有限天津分公司 中海油田服务股份有限公司

CNOOC EnerTech-Drilling & Production Co., Tianjin 300459, China Tianjin Branch of China National Offshore Oil Co., Ltd., Tianjin 300459, China China Oilfield Services Limited, Tianjin 300459, China

深井、超深井成为渤中区块开发的主力。该区块漏失、井壁坍塌等井壁失稳问题严重，给钻井作业带来了极大的挑战。结合已钻井的具体情况，对采集到的岩屑、岩心进行了室内实验分析；应用MATLAB软件模拟岩石坍塌压力分布情况；利用岩石力学相关理论，对泥岩吸水量随时间变化以及岩石强度在钻井液浸泡下的变化规律进行分析，模拟井壁稳定性周期，为今后该地区钻井作业过程中优化钻井设计提供了数据及理论支持。

Borehole stability has always been a problem that all oil fields have been trying to solve, and the cost caused by borehole instability is hundreds of millions yuan each year.With the overall development of Bozhong Block in Bohai Oilfield, deep wells and ultradeep wells are currently the main force for oilfield development.In Bozhong Block, The problems of borehole instability are serious, including leakage and borehole collapse, and they bring about great challenges to drilling operation.The collected cuttings and cores were experimentally tested and analyzed in consideration of the specific situations of drilled wells.Then, the distribution of rock collapse pressure was simulated by using MATLAB software.Finally, according to the theories related to rock mechanics, the borehole stability cycle was simulated by analyzing the water absorbing capacity of the shale over time and the change rule of rock strength in the immersion of drilling fluid.The research results provide the data and theoretical support for the drilling design optimization in the process of well drilling in Bozhong Block.

10.13639/j.odpt.2018.S0.025