百色盆地东部中三叠统基底灰岩预测

PREDICTION OF MIDDLE TRIASSIC BASEMENT LIMESTONE IN EAST BAISE BASIN

汪士昭

Wang Shizhao

上法灰岩是夹于大套中三叠统碎屑岩中的灰岩透镜体,它是盆地与台地两大相区相变线附近地貌陡变带中的沉积,经剥蚀后残留于基底表面的高部即基岩向斜的核部,形成由向斜构造-地层不整合面-岩性诸因素控制的基岩油气藏,生油层为上始新统那读组,储层为中三叠统上一段,盖层为第三系底部之泥页岩,预计在基岩凸起上二段围限的区域内布钻可获成功。

The Shangfa limestone is a carbonate lenticular that is intercalated in a large suite of Middle Triassic detrital rock. It is a particular sedimentation of varying relief zone near facies change line between platform facies and basin facies. Had been weathered and denuded for a long time before Pretertiary, it remained in higher part of the basement surface, and structurally distributed in syncline groove. The formation of oil and gas pools in Shangfa area is controlled and confined by tectonic, stratigraphic unconformities as well as lithologic characters. Source beds is Nadu Formation of Upper Eocene, reservoir bed is the first member of Shangfa Formation and the covering strata are mudstones and shales in bottom of the Tertiary System. To arrange drilling within higher part of basement surrounded and comfined with the second member of Shangfa Formation are expected to success.

10.11743/ogg19910312