川西拗陷上三叠统气田水化学形成演化的重溯

本文在研究区沉积演化、构造演化和上三叠统含水系统、水文地质期定位的基础上, 论证了T3x2水起源于35 g/kg的海相同生沉积盐水, 经历了沉积、沉压埋藏、构造热液3个“期”的浓缩盐化正向变质, 演化成为最高浓度160 g/kg的海相后生沉积孔隙裂隙卤水、浓卤水; T3x4、T3x6水均起源于陆相同生沉积淡水, T3x4经历了沉积、沉压埋藏—淋滤、沉压埋藏、构造热液4个“期”, 主要是高度浓缩盐化正向深变质, 演化成为最高浓度100 g/kg的后生沉积孔隙裂隙盐卤水; T3x6与T3x2经历的期相同, 经高度浓缩盐化正向深变质, 演化成为最高浓度84 g/kg的后生沉积孔隙裂隙盐卤水。

Restoration of the Formation and Evolution of Upper Triassic Gas Field Water in Chuanxi Depression

Based on studies of deposition,tectonic evolution,Upper Triassic aquifer system and hydrogeological age,this paper holds that T_3x~2 groundwater came from marine syndepositional brine of 35 g/kg,and experienced three "periods" of inspissation salt positive metamorphism,namely sedimentation,compaction and tectonic hydrothermal activity.Afferwards,they turned into deuterogenous sedimentary salt brine and strong salt brine of 11 60 g/kg.Both T_3x~4 and T_3x~6 groundwater came from terrestrial facies syndepositional freshwater.T_3x~4 experienced four "periods",i.e.,sedimentation,compaction-leaching,compaction and tectonic hyrothermal activity.The major part was characterized by strongly concentrated salification and forward metamorphic process,and the later evolution into deuterogenous sedimentary pore and fissure salt brine of 100 g/kg.T_3x~6 and T_3x~2 experienced the same periods,resulting in strongly concentrated salification and forward metamorphic process and forming deuterogenous sedimentary pore and fissure salt brine groundwater of 84 g/kg.