Research On Analysis And Application Of Production Decline Models Of Gas Wells In Shale Gas Reservoirs

Shale gas reservoirs have always been very important in the global oil and gas resources,and the efficient development of shale gas reservoirs has long-term strategic significance for the protection of oil and gas supply in China.In this paper,the gas wells of shale gas reservoirs were taken as the research object.By analyzing the production decline models of shale gas reservoirs,the special software for the gas production decline models analysis and production prediction of shale gas reservoirs was compiled to realize the calculation of key parameters of different production decline models and the prediction of the future production of gas wells.Through these functions,the production analysis of gas wells in shale gas reservoirs can be completed,which facilitates the production management of shale gas wells.The main target tasks should be accomplished in this paper are as follows:(1)Analysing the production decline formula of the classical model,such as Arps hyperbolic decreasing model,PLE decreasing model,Duong decreasing model and SEPD decreasing model.Studying the calculation methods of key parameters,such as decreasing rate,decreasing coefficient,decreasing index,index coefficient,initial production and so on.Determining the specific steps of the classic model analysis.Analyzing the law of production decline corresponding to the classical model,and summarizing its advantages,disadvantages and application condition.(2)Deriving the formula of the combined model,such as SEPD-Kerogen combined model,SEPD-Duong combined model and Duong-Arps combined model.Determining the calculation process of the combined model.Calculating combination points,and analyzing the law of production decline corresponding to the combined model.(3)Based on the theoretical research results of production decline models of the shale gas reservoirs,the VB language was used to develop the special software for shale gas production decline analysis under the Visual Basic 6.0 programming environment.The special software of shale gas wells for the gas production decline models analysis and production prediction of shale gas reservoirs realized the caculation of different production decline models conveniently and forecast of future production quickly.(4)Based on the special software for production decline analysis and prediction in this paper,the actual produce data of a production well was analyzed and the prediction production was obtained.Based on the previous research on production decline models about shale gas reservoirs,this paper further deepens the study of shale gas well production decline analysis,and provides certain theoretic reference for production development dynamic forecast of the gas wells of shale gas reservoirs.