Investigation and Application of Pore Pressure Monitoring Method Based on LWD Data

To accurately monitor pore pressure while drilling and improve drilling safety,this paper presented a pore pressure monitoring method based on logging while drilling(LWD)data.Firstly,a real-time data collection and processing program was developed based on WITS data standard and TCP transmission mode,which was able to realize the acquisition and transmission of LWD data.Then,according to the transmission characteristics of LWD data,a pore pressure monitoring model was established based on single-point algorithm.In this model,LWD data were discretized and used to estimate corresponding pore pressure values in real time.The application of this method in several wells of an overpressure basin of South China Sea showed the arithmetical differences between monitoring results and real measured pore pressure values were no more than 10%,proving the method could provide accurate pore pressure data in real time,meet current field requirements,and guide drilling design and operation.