莺—琼盆地流体势分布特点

PROPERTIES OF FLUID POTENTIAL DISTRIBUTION IN YING QIONG BASIN

介绍了流体势（主要是水势和气势）的计算方法，具体分析了莺—琼盆地流体势在剖面上和平面上的分布特点，以揭示莺—琼盆地的油气运移、聚集规律。研究结果认为：油气是从高势区向低势区运移的，并在位于油气运移路径上的低势圈闭中聚集成藏，因而低势区是油气藏形成的有利区块。据此，预测莺—琼盆地内的下第三系陵水组有六个低势区，并结合烃源、储集层、盖层及圈闭等地质条件，对它们分别给予了评价。进而指出：位于①号断裂上升盘的崖１３—１低凸起、崖２１—１低凸起带、中央凹陷、崖南凹陷等低势区为今后油气勘探的有利区块。

The calculation method of fluid potential(being mainly water potential and gas potential)is introduced and the properties of the fluid potential distribution both in section and on plane in Ying Qiong Basin are analyzed,which reveals the rules of oil & gas migration and accumulation in the basin.Through research,it is considered that the oil and gas migrate from the higher potential area to the lower one and are accumulated in the trap with lower potential along the road of migration to form a reservoir,and therefore the lower potential area is the beneficial region of forming oil and gas reservoir.Based on this,it is forecasted that there are six lower potential areas in the Lingshui Formation of Paleogene within this basin and they are evaluated respectively in combination with some geological conditions as hydrocarbon source,reservoir bed,cap rock and trap,etc.,and it is pointed out that these lower potential areas,such as Ya 13 1 low arch(to be located on the uplifted wall of Fault No.1),Ya 21 1 low arch belt,Central depression and Yanan depression,are the favourable regions for oil and gas exploration in the future.