Comprehensive Analysis Method for Water Inrush Source in Fracture-pore Gas Reservoirs with Bottom Water: A Case from M Gas Reservoir

摘要

During the development of M gas reservoir which is a typical fracture-pore carbonate reservoir with bottom water, excessive water production is frequently encountered during the lifetime of gas-producing wells, which generally results in a rapid productivity decline and a remarkable increase in operating costs caused by the handing and treating of large amount of water. Nevertheless, there exists no comprehensive analysis method to accurately obtain it. In combination with previous studies about water inrush source in gas reservoirs and the static and dynamic developing data of M gas reservoir, there are four methods brought up firstly, which are means of water sample salinity analysis, water-gas ratio (WGR) analysis, comprehensive logging interpretation analysis and production performance analysis. Subsequently on the basis of formation parameters and fluid data of M gas reservoir, the mechanism model of fracture-pore reservoir with bottom water have been set up by utilizing the Eclipse software to research the water-invasion principles. According to the dynamic change characteristics of water invasion, the numerical simulation analysis method has been brought up. Finally the identification process is illustrated accurately by taking two representative wells in M gas reservoir for example. A timely and precise identification of water inrush source plays a significant role in understanding the principles of gas-water motion in the reservoir, making corresponding and reasonable development measures and improving the development efficiency.