琼东南盆地地压场与油气运移

琼东南盆地的异常高压主要是在上新世和第四纪时盆地快速沉降产生压实与排液不均衡形成的,水热增压和新生流体对异常地层压力形成有辅助作用,异常地层压力的分布受沉积中心、埋深和岩性变化控制。用地震速度可以计算地下流体压力。各时期各组段沉积地层都有自己相应的正常压实趋势线。速度稳定段主要分布在富含泥质的上新统中,在压力预测时必须进行校正。油气聚集带是在纵向上相对低势层段和平面上相对低势区的结合部位。在气势图中,相对稳定的低势区,实际上就是相对低势等值线的闭合区和挠曲带。

THE GEOPRESSURE FIELD AND ITS RELATION TO PETROLEUM MIGRATION IN QIONG-DONGNAN BASIN China Offshore Oil and Gas (Geology )

Overpressures in Qiongdongnan Basin are mainly resulted from disequilibrium of compaction, gas generation and thermal expansion of fluid during Pliocene and Quaternary. The distribution of overpressures is controled by depocenters, burial depth and lithology,etc. Formation fluid pressure can be calculated by using seismic data. Each formation has its own normal compaction trend. Intervals with stable velocity are within argelaceous rich Pliocene and corrections must be made dur-ring pressure prediction. Petroleum accumulations should be within the vertically relative lower hydraulic potential combined with laterally relative lower potential in overpressure areas. The relative stable low potential zones are actually the closure areas and flecture areas of the relative low potential isopachs.