AHP Application to Shale Gas Exploration Areas Assessment in Sichuan Basin

In order to analyze key factors of profitable shale gas exploration and development for shale gas exploration areas in Sichuan Basin,the theory of analytical hierarchy process has been used to establish an optimization hierarchical structure model of shale gas exploration area assessment:goal layer,criterion layer,sub-criterion layer and project layer.The model is established by four steps:building up a hierarchical structure model,constructing judgment matrix,making single hierarchical arrangement and its consistency test,and forming total hierarchical arrangement and its consistency test.The weight factors are computed for the assessment.The main factors for the shale gas exploration and development are:geological condition,development condition and support condition.Geological condition is the first factor for shale gas exploration area assessment and its weight is up to 0.637 0.Sub-criterion layer mainly contains 12 evaluation indexes:thickness,TOC,R_o,gas content,profitable space,burial depth.etc.Gas content,natural facture growth,pressure coefficient and market demand are the key indexes for shale gas profitable play assessment.Jiaoshiba and Changning shale gas areas are of high marks and are the most favourable areas for the shale gas development according to the evaluation index given for weighted summation method.It is suggested that the assessment method of "different levels,focus and orders" should be used in the shale gas exploration in order to avoid unnecessary loss.