井底环空压力与地层压力的平衡关系是影响钻井作业安全的重要因素。由于井下工况复杂多变,而目前通过水力模型理论计算所得的井底压力与实际压力值存在较大的误差。文中介绍了一种可以测量近钻头处钻压、扭矩、环空压力、环空温度及钻柱内压力等参数并将测量数据实时传输至地面的随钻压力测量系统(PWD)。依靠PWD的实时测量数据,可以实时修正井筒水力模型,解释井底工况,预测钻井事故。现场试验证明,该测量系统测量参数准确、工作稳定可靠。通过与存储式PWD测量数值对比,该测量系统有较高的测量精度,具有实时传输测量数据功能,可为钻井作业提供有力的技术支持。
The balance relationship between bottom hole annulus pressure and formation pressure is a key factor to affect the drilling operation safety.Because of the complex and various situation underground,there is a big error between the actual bottomhole pressure and calculated one.The paper introduced a PWD system which can measure the parameters of weight on bit(WOB),torque,annulus pressure,annulus temperature,pressure inside the drill string,etc.,and transmit the measurement data to the ground in real time.With the real time measurement data,the wellbore hydraulic model can be corrected in real time,and the underground situation can be interpreted in real time,what is more,the drilling accident can be predicted in real time.The field test proves the accuracy and reliability of the measurement system.Compared with the storage PWD system,this measurement system is more accurate,and has the function of transmitting the measured data in real time,so it can offer powerful technical support for drilling operation.