Oil Enrichment Area Optimization Of Chang7 Reservoir In Tiebiancheng Area,Ordos Basin

Chang7 oil formation of Tiebiancheng area in Ordos basin has initiated development in recent years,For now,the production is discontent,a large amount of oil has not been developed.Therefore the further geological research about enrichment pattern of Chang 7 tight oil is urgent.this paper which multiples logging date,core observation and testing results,using theories of sedimentary and reservoir geology as the main theoretical guidance,studies with system on stratigraphic structure,Sedimentary microfacies Reservoir characteristics and oil accumulation regularities,and obtains following conclusions.Chang7 oil formation is divided into three layers called Chang7₁ Chang7₂ and Chang7₃ by fine contrasting.The thickness is between 31.5m and 42.9m.All three layers have Good inheritance.Stratum of Chang7 is a monoclinic,the tendency is west-northwest.Chang7₂ and Chang7₃ develop delta front deposit and beneficial sedimentary microfacies is underwater distributary channel.The whole southwest distribution.As a result of lake basin extending,Chang7₁ develops shallow lake subfacies,which leads to sand bodies underdeveloped.Chang7 reservoirs mainly contains process of compaction,cementation,metasomasision and dissolution.Chang7₂ layer is divided into three diagenetic facies including strong solution phase of kaolinite?relatively high-quality reservoirs?,carbonaceous asphalt and silica cementation-weak solution phase,carbonate cementation-weak solution phase?bad reservoirs?.Plane distribution of diagenetic facies can be used as important parameter in reservoir evaluation.Using conventional mercury injection and image pore analysis to research on characteristics of mico-pore throat.Research shows pore throat structure of Chang7 reservoirs are poor sorting,fine skewness,high displacement pressure and well distribution.Corresponding to different pore and throat characteristic parameters,Chang7 reservoirs is divided into three type.According to core analysis three small layer are Sequenced by reservoir physical properties.Chang7₂ has the best properties,Chang7₃ takes the second place Chang7₁ is the worst.Chang7 reservoirs is divided into 4 categories?type?,?₁,?₂ and??.Combining reservoir profile and literature investigation,Chang7 reservoirs of Tiebiancheng area are updip pinchout and lens reservoirs,Self-generation,self-storage and first accumulation followed by densification.The regular of enrichment is controlled by reservoir physical property.Chang7₂² is conducted enrichment area optimization and obtains reservoir of type?₁+?₂,the area reach to 116.18 km².