空气泡沫钻井流体井壁稳定性研究

Well Stability Study of Using Air-Foam Drilling Fluid

针对空气钻井中遇到地层大量出水时无法钻进、需转化为空气泡沫钻井的情况,优选出了有利于空气泡沫流体钻井时井壁稳定的处理剂GXG、AP-1和WJ-3,形成了一套具有良好井壁稳定性能的空气泡沫钻井流体配方,对该泡沫流体的抑制性、井壁稳定性等性能进行了评价。结果表明,所研究的空气泡沫钻井流体具有强抑制性,页岩回收率达97.4%,页岩膨胀量较清水降低67.1%。该空气泡沫钻井流体能使泡沫在井壁上形成保护膜,阻止水进入地层,有效防止井壁坍塌,井壁稳定效果良好。

Air drilling is stopped and has to change into air foam drilling when abundant formation water is produced. In order to solve this problem, an air foam drilling fluid system were formulated by optimi- zing additives GXG,AP-1 and WJ-3. The inhibitive ability and wellbore stability of this system was evaluated. Results showed that this fluid system has good inhibitive ability with shale recovery of 97.4% and the amount of shale expansion reduced by 67.1% compared with water. This fluid system has good wellbore stability by forming a protective film to prevent water from entering formation and prevent wellbore collapse.