广西柳桥地区上二叠统礁灰岩中发现沥青

Discovery of Asphalt in the Upper Permian Reef Limestone in Liuqiao, Guangxi

研究区位于广西扶绥县东门镇和柳桥镇之间,主要分布上二叠统和下三叠统地层.上二叠统包括合山组、上二叠统礁灰岩和大隆组.下三叠统罗楼组由泥岩和灰岩组成.大隆组主要为放射虫硅质岩和泥岩,含有丰富的放射虫、有孔虫、介形虫、菌藻类、腕足类、菊石类和双壳类化石,是好的烃源岩层.礁灰岩具有大量裂隙和孔洞,是好的储集层.在柳桥地区东攀剖面、岜陇剖面和岜料剖面,礁灰岩裂隙和孔洞普遍被沥青充填.研究区上二叠统礁灰岩是值得注意的油气勘探远景区.

The studied region, located between Dongmen and Liuqiao at Fusui in Guangxi, mainly consists of Upper Permian and Lower Triassic strata. The Upper Permian is divided into three units; they include the Heshan Formation, Upper Permian reef limestones, and Dalong Formation. The Lower Triassic mudstone and limestone are known as the Luolou Forma- tion. The Dalong Formation consists predominantly of radiolarian cherts and mudstones, and contains abundant late Chang- hsingian fossils, including radiolarians, foraminifera, ostracods, fungus spores, brachiopods, ammonoids and bivalves. These sedimentary and lithological features of the Dalong Formation are indicative of good source rocks. The reef limestones are characterized by plentiful fractures and pore spaces, showing a nature of good reservoirs. The fractures and pores are generally filled by asphalt in Dongpan, Balong and Baliao sections at Liuqiao in southwestern Guangxi. On these points, the Upper Permian reef limestones in Liuqiao area would be of significance for the future exploration of oil and natural gas.