Comprehensive evaluation of reservoirs based on the entropy weight method,TOPSIS,and the gray correlation method:Taking the Huangliu Formation in Yinggehai Basin as an example
The Upper Miocene Huangliu Formation in Yinggehai Basin is a high temperature and high pressure system.The geothermal gradient of the formation is more than 4℃/100 m,and the pressure coefficient is greater than 1.6.There is a high potential of geothermal resources in the basin,but a geothermal resource evaluation of the area has not yet been carried out.Through nine drilling wells,logging,recording,production data and formation temperature measurement data of the latest seven wells and rock thermophysical parameter tests,a comprehensive evaluation of the reservoir is carried out based on the reservoir storage performance,combined with thermophysical parameters.Taking Huangliu Formation as an example,based on the evaluation of the six-parameter relationship of the reservoir,this paper optimized seven thermal reservoir evaluation indexes porosity,permeability,shale content,formation coefficient,formation temperature,heat generation rate,and thermal conductivity,and adopts entropy weight-TOPSIS-gray correlation method to carry out a comprehensive evaluation of this type of thermal storage.The results show that among the seven evaluation indexes,porosity,permeability and stratigraphic coefficient accounted for a relatively large weighting of 21.31％,21.07％and 20.42％,respectively,and were the main influencing factors.Considering the Euclidean distance of the positive and negative ideal solutions of the evaluation parameters and the gray correlation degree between each index and the positive and negative ideal solutions,the relative closeness degree under different decision preferences was used to perform a quantitatively evaluate,the results show that the relative closeness of reservoirs H1-2,H1-1,and H2-2 is relatively high,which is 0.624,0.606,and 0.529,respectively,and the reservoirs have better properties,which can be used as the key research object for the Huangliu Formation thermal reservoirs in the Yinggehai Basin.
万方数据
维普
