Research on Main Controlling Factors of Gas Recovery Rate of Volcanic Gas Well in Xushen Gas Field

It is the main problem in gas reservoir development to determine the reasonable gas production rate, which must be solved firstly. Volcanic gas reservoir in Xushen gas field is composed of contiguous superimposed volcanic rocks of different sizes, and the gas-water interface between the volcanic rocks is not uniform, the porosity and permeability structure of the reservoir is complex, and the dynamic and static characteristics of gas Wells are very different. Gas reservoir engineering combined with numerical simulation technology reveals the main controlling factors of gas recovery velocity of elastic gas drive and water drive gas Wells. Elastic gas drive well: (1) The influence of formation coefficient and well controlled reserves on gas recovery rate is revealed. (2) The characteristics of stable production time, recovery degree and economic benefit of gas well at different production rates are described. (3) The effects of different gas production rates on gas well recovery and economic benefits during the whole production period are studied. Elastic water drive gas well: (1) The influence of gas production velocity change on oil recovery and economic benefits of fractured water channeling (or pore-water cone) type gas well is analyzed; (2) The relationship between gas production rate, stable production capacity and economic benefit of gas well with uniform formation water propulsion. It is of great significance for determining reasonable gas production rate of Xushen volcanic gas well.