用钻井参数实时监测地层压力的新方法

计算地层压力的方法很多,但是在不同地区、不同地质和沉积环境下计算结果有很大的变化,甚至于在某些地区地层压力的计算精度小于其常用的经验公式。综合考虑了由欠压实、流体膨胀和它源异常引起的异常地层压力,使用遗传算法,利用钻井参数数据,实时地从钻速中分离出井底压力变化的信息,实现地层压力的实时计算,从而剔除了正常泥岩趋势线的概念。现场应用表明,采用新方法提高了地层压力的计算精度。

New Method of Formation Pressure Real Time Monitoring Using Drilling Parameters

Lots of methods are available for calculating the formation pressure, while the results vary greatly in different area, different geological condition and different deposition environment, and sometime the accuracy is not satisfactory enough. The new method omitted the concept of normal shale trend line, and took such occasions as the abnormal formation pressure by under-compression, abnormal formation pressure by fluid inflation and abnormal formation pressure by other factors into consideration. The method of heredity is used for abnormal formation pressure calculation, and downhole pressure changing is separated real time from ROP data, thus realizing the real time calculating of formation pore pressure. Field application of this method improves the accuracy of formation pore pressure calculation.