摘要
Biogas is a kind of natural gas with special generation process.Because the formation and accumulation mechanism has not been defined,it is difficult to predict the resources of biogas accurately using the genetic methods.In this paper,a new statistics method for predicting the undiscovered biogas resources was developed based on the analysis of biogas genetic types and formation conditions,and the evaluation units were divided,that is to predict the size distribution of undiscovered biogas reservoirs with truncated shifted Pareto distribution model,build the triangular distribution function to predict the number distribution of undiscovered biogas reservoirs,finally use Monte Carlo method to estimate the undiscovered biogas resources in the study area.The resources of undiscovered biogas in Jiyang Depression were found.The results show that the size distribution of biogas in Jiyang Depression belongs to log-normal distribution,most likely to find biogas reservoirs whose reserves is about 0.02-0.12 billion cubic meters.In the shallow formation of Dongying and north of Huimin Sag,it is possible to find large primary biogas reservoirs,but in Zhanhua Sag,Chenjiazhuang and Binxian-Linfanjia Uplift,there are small oil-degradation biogas reservoirs to be found.The undiscovered biogas resources in Jiyang Depression are about 42.474 billion cubic meters.