新场气田上三叠统须家河组五段天然气成藏主控因素分析

Main Controlling Factors of Hydrocarbon Accumulation for 5th Section Xujiahe Formation Upper Triassic Series in Xinchang Gas Field

摘要: 新场气田地处四川盆地川西坳陷中段北东东向大型隆起带上，上三叠统须家河组五段(T₃x₅)属三角洲前缘–滨浅湖亚相沉积，泥岩发育，为研究区主要烃源岩之一。近年的勘探中，T₃x₅取得了重大突破，亦成为新场气田的新产层。由于T₃x₅呈现“泥包砂”的地层结构特征，其天然气成藏条件显得较为复杂。从构造特征、储层预测、裂缝地震预测等方面对气藏的主控因素进行了评价，综合分析认为T₃x₅成藏受多种因素共同控制。

Abstract: Xinchang Gas Field was situated in the NEE large uplift belt of the Western Sichuan Depression. The 5^th member of Xujiahe Formation (T₃x₅) belonged to a delta front and shallow lake facies deposit, where mudstone was developed; it was one of the main hydrocarbon source rocks in the study area. In recent years, a great breakthrough has been obtained in the exploration in T₃x₅, and it became a new production zone in Xinchang Gas Field. Because of the structural characteristics of “sand in mud”, the natural gas accumulation condition was more complex. The main control factors for the gas accumulation were analyzed from the aspects of structural characters, reservoir prediction, the seismic prediction of fractures, and so on. The result of integrated analysis indicates that the accumulation of T₃x₅ is controlled by multiple factors.