Optimization Of Evaluation Methods For Shale Gas Resources

In our country,the geologic conditions of shale gas are complex,the types of sediments are varied and the degrees of exploration are different.In this context,a single resource evaluation method can not meet all the types of conditions at the same time,and it is very important to select the targeted resource evaluation methods according to the actual situation.Witch the combing of the shale gas resource evaluation methods systematically,it is pointed out that the influencing factors of resource evaluation methods selection are mainly exploration degree,sedimentary facies and tectonic action.Based on the workload of exploration and development,the shale gas exploration and development degree can be divided into four stages: low,medium,tall and high.The type,richness and qualityofparameters are diffierent in each stage.The distribution of organic matter shale and the change characteristics of related parameters are varied from marine to submarine transitional and to terrestrial,the prototype basin to reconstruction basin and to residual basin.The change of exploration and development degree and geological conditions affect the optimization of resource evaluation methods through the change of key parameters of shale gas resource evaluation.The shale gas resource evaluation methodsare discussed and optimized respectively according to the parameter characteristics of different exploration and development degree,the sedimentary environment and the basin type under the tectonic action.The area with low exploration and development degree can choose genetic method,analogy method,size sequence method and delphi method.The area with medium exploration and development degree can choose basin simulation method,volume method,probabilityvolume method and discrete element method.The area with tall exploration and development degree can choose material balance method,decline curve method and the methods the same with the medium degree.The area with high exploration and development degree can choose FORSPAN method,material balance method,decline curve method and size sequence method.The marineorganic matter shale can choose genetic method,analogy method,delphimethod,volume method and material balance method.Thesubmarine transitional organic matter shale can choose area abundanceanalogy method,EURanalogy method,delphi method,probabilityvolume method,basin simulation method and size sequence method.Theterrestrialorganic matter shale can choose genetic method,analogy method,delphi method,discrete element method,probabilityvolume method nd size sequence method,the decline curve method and FORSPAN method can be used in every sedimentary environment.The prototype basin can choose genetic method,volume method and material balance method.The reconstruction basincan choose genetic method,probabilityvolume method,discrete element method and material balance method.Theresidual basin can chooseprobabilityvolume method,discrete element method and size sequence method.Analogy method,delphi method,decline curve method and FORSPAN method can be used in every basin type.The resource evaluation methods of the three types of exploration,sedimentary environment and basin type are optimized,and the optimal method of resource evaluation method is put forward at the same time.The research results can solve the problem that the evaluation method of shale gas resources is different under different conditions,and break the single method evaluation mode,which has certain theoretical innovation and guiding significance.