The Decline Analysis Technology Of Shale Gas Production Forecast

Shale gas extraction is very important for China’s energy security.The poor permeability of shale gas reservoirs resulted in the shale gas exploitation with the characteristics of high initial output and extremely rapid decline.The decline in production forecast is a major part of dynamic analysis.There are many methods for predicting the decline of production,and their applicable conditions or applicable stages are different,which leads to confusion in practical work and greatly reduces the reliability and accuracy of prediction.In view of this,in-depth analysis of the Pros and cons of shale gas production decline prediction methods and put forward a reasonable combination of use conditions has strong practical significance,and can provide a reliable analysis method for shale gas production capacity forecast.On the basis of extensive literature research,this paper selected three models of Arps,SEDM and DUONG by analyzing the applicable conditions and stages of different production decline models.According to the distribution of typical curve characteristic line segments,the type of flow phase is determined,and a corresponding output decline analysis model is established to set the constraint condition prediction technology recoverable reserves.For application,a RATE TRANSIENT ANALYSIS FOR SHALE GAS WELLS(RTA)was prepared.Through case studies,it is recognized that the Arps、SEDM and Duong decline model are all empirical production decline models.The fitting effect of different types of shale gas well production data is different,and there are different degrees of error for the prediction of EUR.It is necessary to select or use a combination of predictive models according to the flow stage.