川东沙罐坪气田石炭系储层流体及压力特征分析

Analysis of Reservoir Fluid and Pressure Characteristics of Carboniferous in Shaguanping Gas Field in Eastern Sichuan Basin

摘要: 川东沙罐坪气田石炭系是目前勘探的重点。本文基于钻井、录井、岩心及地化分析等资料，对石炭系储层中天然气和地层水的性质进行剖析，通过研究各井折算至海拔−4243 m时的压力分析储层流体压力特征并绘制不同时期的气藏地层压力等值线图对储层的连通性进行分析。研究表明，构造区气藏属低含硫的干气气藏，地层水均为CaCl₂型，流体类型为典型的交替停滞型地层水；整个气藏的连通性较好，原始状态全气藏为统一的压力系统，且边缘井的压力随着中心压降漏斗的加深而逐步下降。另外，气藏内高中低渗储渗单元的不同导致不同井区的压降存在差异性。

Abstract: The Carboniferous of the Shaguanping Gas Field in East Sichuan Basin is the focus of current ex-ploration. Based on drilling, logging, core, and geochemical analysis data, this paper analyzes the nature of natural gas and formation water in the Carboniferous reservoir. The reservoir fluid pressure characteristics were analyzed by studying the pressure of each well converted to an elevation of −4243 m, and the reservoir pressure contour maps in different periods were plotted to analyze the connectivity of the reservoir. The research shows that the gas reservoir in the structural area is a low-sulfur dry gas reservoir, the formation water is CaCl₂ type, and the fluid type is typical alternating stagnant formation water; the connectivity of the entire gas reservoir is good, and the entire gas reservoir in the original state is a unified pressure system, and the pressure of the marginal wells gradually decreases as the pressure drop funnel deepens. In addition, the difference in the high, medium, and low permeability reservoirs in gas reservoirs leads to differences in pressure drop in different wells.