川西坳陷上三叠统气田水及其聚气成藏的评价

Evaluation on Gas-Field Water and Gas-Accumulation in the Upper Triassic in the Western Sichuan Depression

在简述地质构造骨架基础上,论证了川西坳陷上三叠统为半开敞型水文地质构造系统,划分和揭示了主要含水系统须二、四段气田水TDS、水头值的分布规律性和各自的分带,提出将两者与其所在环境结合的地下水地球化学动力带分为氧化——还原环境溶质迁移的卸压带(排泄带)、还原环境溶质迁移聚集的稳压带(滞流带)和强还原环境溶质分异纯化的高压带(水压形成带),综合评价有利于聚气成藏的地带。

This paper, based on the briefing geological tectonic frames, demonstrates semi-open hydrogeological tectonic system of the Upper Triassic depression of the western Sichuan and describes that the main aquifers should make clear TDS, water head distribution and their zoning in the gas field, as the result, the comprehensive assessments and prediction may be obtained where the favorable accumulation of oil/gas under the conditions of groundwater geochemical dynamics zone divided into oxidation-reduction environment fluid solute migration discharge zone and reduction environment fluid solute migration gathering stable pressure zone （retarded flow zone） and the strong reduction environment fluid solute separated purified high pressure zone （water pressure forming zone） from the groundwater system with its environment.