提出了一种基于随钻测井资料的地层压力监测方法,能在钻井过程中利用随钻测井资料实时监测地层孔隙压力。首先,以WITS数据格式和TCP传输方式为基础开发了随钻测井数据实时采集程序,实现了随钻测井数据的实时采集;其次,根据邻近地区的已钻井资料建立初始压力监测模型,然后利用实时采集的随钻测井数据对目标井进行压力监测;最后,利用钻井过程中获取的地层压力信息(实测压力、钻井液密度等)对初始模型和压力计算结果进行校正,进而获取较为准确的地层压力监测结果。在理论研究的基础上开发了一套随钻地层压力监测系统软件,介绍了其主要功能模块。该监测系统在南海莺琼盆地进行现场应用,结果表明,系统能够准确监测地层压力,运行稳定、操作方便、监测精度较高,可以满足工程需要。
A kind of formation pressure monitoring method on the basis of the logging while drilling (LWD) data was formulated. It can conduct a real-time monitoring of formation pore pressure using LWD data in the process of drilling. First, based on the WITS data format and the TCP transmission mode, the LWD data real-time collection program was developed, thus achieving the real-time collection of LWD data. Second, the initial pressure monitoring model was established according to the drilled well data of the neighboring region. Then, the LWD data obtained by real-time monitoring were used to conduct a pressure monitoring of the target well. Finally, the formation pressure information (such as actually measured pressure, drilling fluid density, and so on) obtained in the process of drilling was used to correct the initial model and the pressure calculation result so as to obtain the relatively precise formation pressure monitoring result. A series of system software for formation pressure monitoring while drilling were developed on the basis of theoretical research, mainly including the function modules of initiation, LWD data real-time collection and processing, formation pressure monitoring, real- time curve display, real-time early warning and pressure section output. The field application of the system for formation pressure monito- ring while drilling in the Yingqiong Basin of the South China Sea shows that the system can exactly monitor formation pressure. It runs smoothly with convenient operation and high monitoring precision, thus satisfying the engineering requirement.