关键词: 特低渗透率, 储层, 岩石物理相, 灰色理论, 综合评价指标, 地层参数, 含油有利区, 分布规律

Abstract: The extra low-permeability reservoirs in the middle part of Shaanbei slope are affected by many factors,such as sedimentary environment,diagenesis and structure.Both macroscopic physical property and micropore types of these reservoirs have strong heterogeneity,so the quality and percolation structure of the reservoir have a large difference.The flow zones are complex in the extra low-permeability reservoirs of the middle part of Shaanbei slope.A determination method was presented for favorable oil-bearing areas in the extra low-permeability reservoir using flow units of petro-physical facies.A comprehensive evaluation system of "dessert" of petro-physical facies was developed using various parameters for describing geologic features of porous medium,including flow zone indicator,energy storage parameters,diagenetic synthetical coefficient,thickness of single-permeability sandstone,effective thickness of oil layers,the ratio of sand body to formation thickness,permeability,porosity,shale content,and distribution frequency and density of inter-players.Above various parameters including permeability and storage capability,oil and gas bearing features and heterogeneity of reservoirs were integrated and synthesized by gray theory.The locations and distribution of favorable oil-bearing area were effectively determined by using "dessert" of TypeⅠ and TypeⅡ petro-physical facies.The results could fully reflect geological features of the favorable oil-bearing areas in the extra low-permeability reservoirs.

Key words: extra low-permeability, reservoir, petro-physical facies, gray theory, comprehensive evaluation index, formation parameter, favorable oil-bearing, areas distribution regularity