川西含油气拗陷上三叠统含水系统和水文地质期的划分和定位

The Division and Positioning of Upper Triassic Aquifer Systems and Hydrogeological Periods in Western Sichuan Petroleum depression

本文通过沉积环境、岩性组合、水化学、碳同位素等的论证,将川西拗陷上三叠统划分为须家河组须二段、四段、六段3个主要含水系统,须一段、三段、五段3个相对隔水系统;通过地壳运动、水动力条件、地球物理场等论证了各含水系统经历的水文地质期的次数和型式。"统序"和"期序"的建立,从宏观上构建了深层水形成演化的模式,为深层水及其与聚气成藏之间规律性联系指示了研究的思路、途径和方向。

The deposition environment, rock assemblages, hydrochemistry, carbon isotopes of Chuanxi depression were studied in this paper. Based on the results, the authors divided Upper Triassic Xujiahe Formation into three main aquifers, namely the 2nd, 4th and 6th members, and three aquitards, i. e., the 1st, 3rd and 5th members. Studies of tectonic movements, hydrodynamics and geophysical fields show that the aquifers have experienced different hydrogeological periods. The construction of aquifer series and hydrogeological periods helps build a general model for deep groundwater formation and evolution and also guides the study of the relationship between the deep groundwater and the gas reservoir.