基于智能钻柱的控压钻井溢流实时评价方法

Research of Overflow Real-time Evaluation Method Based on Intelligent Drill String During Manage Pressure Drilling

在对传统地面溢流评价方法滞后性问题进行分析的基础上,开展了基于智能钻柱的井下溢流实时评价方法研究。该方法是利用分布于智能钻柱上的多个压力传感器将所钻井段分为若干个控制区域,通过监测各区域中地层流入井筒的流体流量来确定溢流大小和发生溢流的位置。基于软测量的基本思想,使用了两相流井筒瞬态流动模型,并采用无迹卡尔曼滤器对智能钻柱上传感器节点处井筒压力测量值进行了实时校正。现场试验证明,与井筒压力最接近的地层孔隙压力区域最易发生溢流,基于智能钻柱技术的溢流实时评价方法能够在溢流发生后的100 s内较为准确地预测地层流入井筒的流体流量和发生溢流的位置,具有很高的实时性和可靠性,发展潜力巨大。

Based on the analysis of the problem of traditional overflow evaluation method, we study a kind of real-time overflow evaluation method using intelligent drill string. With this method we can determine the size and location of the overflow by monitoring the influx rate into the wellbore, as the distributed sensors along the drill string enable us to divide the annulus into many control volumes. We build the real-time calibration models of pressure measurement at distributed sensors along the intelligent drill string. Field test shows that overflow occurs where the well pressure is close to the pore pressure. The method can accurately predict the influx rate into the wellbore and the location of overflow within 1 O0 seconds after the initial overflow and theretbre is of great instantaneity and reliability.