Quantitative evaluation of low-permeability sandstone diagenetic facies based on DEA method: A case study of Chang 81 reservoirs in the Yanwu region, Ordos basin
MA Baoquan
YANG Shaochun
ZHANG Hong
BAI Qinglin
YANG Zhaolin
Abstract：Diagenetic facies is one of the main factors controlling the reservoir quality.The quantitative characterization of diagenetic facies plays an important role in reservoir evaluation and prediction.This paper selected Chang 81 reservoir of Yanwu area in Ordos basin as the objective layer,quantitatively evaluated the diagenetic facies by applying the data envelopment analysis (DEA) on 15 selected parameters relevant to petrographic characteristics,diagenetic processes and pore structure etc.Taking the corresponding reservoirs of the diagenetic facies as the characterization units,the evaluation group and the numerical model were established by characterization parameters of all diagenetic facies.Then each parameter affecting the quantitative characterization was considered to solve the linear programming model.The results suggest that there are five intervals of diagenetic facies indexes,they are 1.00-0.85,0.85-0.60,0.60-0.50,0.50-0.35 and 0.35-0,which have good relationship corresponding to the diagenetic facies.The diagenetic facies indexes show a positive correlation with the absorption intensity and a negative correlation with the residual oil saturation.The diagenetic facies of weak corrosion with chlorite mat and of corrosion with unstable components are favorable reservoirs in the Yanwu region.The diagenetic facies indexes of them range from 1.00 to 0.60,with higher oil displacement efficiency and lower residual oil saturation.The pore-throat system is good,with the porosity ranging from 10％ to 17％ and the permeability ranging from 0.50 to 10.00 mD.
Keywords：Ordos basinYanwu areadiagenetic faciesdata envelopment analysisreservoir quality evaluation
Publication Date：2018-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：10( 357-366 )