深水钻井沿隔水管超声波气侵实时监测技术研究

摘要

早期溢流监测对预防石油开发钻井过程中井喷失控恶性事故具有至关重要的作用.深水钻井作业过程中在不破坏钻井隔水管力学结构的前提下,基于非接触式超声波测量手段沿程监测隔水管内部钻井液流动特征参数,设计了适合深水钻井隔水管气侵监测系统.实验模拟分析了深水钻井隔水管气侵监测系统超声波时差法和超声波多普勒法的气侵监测效果,结果表明:超声波时差法虽然在清水中可以实现含气率测量,但是对于水基钻井液并不适合;极小含气情况下,多普勒频移量出现极大衰减,并随着含气率的增加而下降,因此超声波多普勒方法对气侵早期识别具有可行性.上述成果对于深水钻井早期溢流监测有指导意义.%Early kick detection is of great significance to prevent blowout in well drilling operations.During deep water drilling operations,early kick detection can be realized by using non-intrusive ultrasonic meas-urements to monitor the flow characteristics of the drilling fluid inside the riser without changing the riser's mechanical structure.And then the kick detection system for deep water drilling operations was designed. The phenomena of kicking inside the riser were experimentally investigated in the laboratory by ultrasonic time difference method and ultrasonic Doppler method.It is found that the time difference method is suit-able to measure the void fraction of water,but not for the water-based drilling fluid.It is also found that the frequency shift of Doppler severely attenuates when the void fraction is tiny,and it keeps decreasing as the void fraction increases.Hence the feasibility of using Doppler method to detect the early kick inside the riser is proved from this study.The above findings can be used for guiding the early kick detection during deep water drilling operations.