琼海凸起珠江组砂岩钙质层成岩模式探讨

从层序地层与成岩作用的关系入手， 利用岩石铸体薄片镜下鉴定的结果， 对文昌 13–1/13–2 油田珠江组第一段和第二段钙质层进行对比， 分析了沉积体系对矿物离子的控制因素， 并结合岩石的成岩演化， 深入探讨了琼海凸起珠江组中钙质层 （即富含方解石胶结物和生物碎屑的砂岩） 的分布及成岩模式。研究结果表明， 珠江组第一段和第二段的钙质层的形成具有相同的主控因素， 即沉积体系域； 从珠江组第二段到第一段， 成岩作用具有一定的连续性和突变性。

Palaeogene Fault System and Hydrocarbon Accumulation in East#br# Wushi Sag

Paleogene complex fault system has always been a key factor in the success of oil and gas exploration in East Wushi Sag. In this article the time of faults movement，their classification and the structural evolution are studied. The results show that the evolution of East Wushi sag can be divided into weak rifting stage in Paleocene -Early Eocene，strong rifting stage in Middle-Late Eocene and strike-slip weak stretching stage in Oligocene. Besides，3 sets of fault systems can be recognized： the early fault system formed in Changliu Formation to Liushagang Section 3 Formation sedimentary stage（T100 T86），the late fault system formed during Liushagang Section 2 Formation to Weizhou Formation sedimentary stage（T83 T60）and succession fault system formed in all the Palaeogene time（T100 T86）. In addition，stretching structure，strike-slip structure and inversion structure have been found in study area. While the tectonic controls on the distribution of source rock and the filling evolution of sediment systems has been discussed，as well as the fault activity impacts on the trap formation，distribution，and the accumulation of hydrocarbon. Based on the analysis of the elements of reservoir formation，the central uplift and the north tilted fault block are the favorable prospecting areas. And the research has some guidance and reference value for the future oil and gas exploration，target evaluation and preference，and geological research.