Productivity Evaluation Study of Shale Gas Reservoirs

Abstract

The seepage mechanism of unconventional gas is very complex, and has a unique seepage mechanism and dynamic flow characteristics. It is difficult to use conventional gas production capacity to predict recoverable reserves. In this paper, starting from fluid mechanics, based on reservoir characteristics of the shale gas fracturing, a composite model of shale gas reservoirs was established, and stable production time was determined. We analyzed the effects of inside and outside zone permeability, the radius, pressure gradient, desorption influence of the compression factor and reservoir thickness, etc., and the established a shale gas well productivity equation refer to Vogel equation. The results show that: area permeability, penetration outside the area, zone radius, reservoir thickness and desorption compression factor were sensitive to shale gas production capacity; skin factor and the pressure gradient is not sensitive factor; through reliability analysis, the productivity formula which was referred to Vogel equation can determine the production capacity of shale gas wells quickly and accurately.