流体包裹体在川西南部上三叠统天然气成藏研究中的应用

有机流体包裹体是含油气系统中水-岩相互作用的产物,记录了盆地流体生成、运移和演化的信息。系统观测了川西南部邛西、平落坝及白马庙气田上三叠统须二段原生气藏和侏罗系次生气藏储集层的有机包裹体,并选择性地对某些包裹体进行了激光拉曼光谱分析,而后结合构造埋藏史和烃源岩成熟热演化史对川西南部须二段气藏的成藏过程进行了系统分析,认为川西南部须二段气藏的形成过程大致是连续的,经历了印支晚期少量注入,到燕山期大量注入,再到喜马拉雅期调整、少量注入的过程,其主要充注时期为燕山期(195~95 Ma)。该研究成果对认识研究区气藏地质特征、成藏规律和勘探部署有重要的借鉴意义。

Application of Fluid Inclusions to Research on Natural Gas Accumulation in the Upper Triassic of the Southern Part of West Sichuan

Fluid inclusions are resulted from the interaction between water and rocks in petroleum systems, and they record the information of the fluid generation, migration and evolution of a basin. The authors carried out an investigation on the type, distribution characteristics, homogenization temperature, salinity and composition of fluid inclusions in late Triassic clastic rocks in the Pingluoba, Qiongxi and Baimamiao gas fields in the southern part of the west Sichuan foreland basin. Some samples were analyzed using laser Raman spectroscopy. And in combination with the buried history and the maturity history of the source rock, the hydrocarbon accumulation process of the second member gas reservoir of Xujiahe Formation in the basin. The second member gas reservoir experienced a continuous process of formation: small charge in the Indonesian period, large charge in the Yanshan period, and adjustment and small charge again in the Himalayan period. The main charge time is 195~95 Ma. The research is very important to reorganize the gas reservoir geology characteristics, hydrocarbon accumulation rules and to make exploration strategies.