Oil And Gas Distribution Of The Yingcheng Formation In The Longfengshan Area Of ??Changling Fault Depression

As hot spots of exploration and development of oil-gas reservoir in Changling fault depression of Songliao Basin,study for Longfengshan area is attached to importance due to its low porosity structure and low permeability reservoir.The structure is located in the south of deep concave in Changling fault depression,Yingcheng formation is main gas-producing strata with great exploration potential.Effective oil and gas reservoir is distributed ambiguously due to its worse physical property of reservoir in research region,effective reservoir are thin and great horizontal change.Given the exploration situation of Yingcheng formation,based on the summary of previous research results,the paper studies symmetrically for oil-gas distribution pattern in the Yingcheng formation of research region,to further recognize geology rules of gas field accumulation in Longfengshan area,and eventually makes breakthrough and increases rapidly in production.The paper studies sedimentary microfacies,distribution of sand bodies,petrologic characteristics of reservoir,corporality character and diagenesis by datum of regional geological,dynamic production,well logging and mud logging.It also analyzes and learn about distribution rules of oil-gas combining basic elements of oil and gas reservoir accumulation.Based on full recognition for features of structural evolution and depositional setting,the study believes that this region appears fan deltaic,braided river delta and lacustrine depositional system,which marks off several subfacies like deltaic plain,inside delta front,outside delta front,shore-shallow lake and semi-deep lake,which can further recognize microfacies like underwater distributary channel,braided channel,beach bar sand.Oil-gas distribution is affected by changeable thickness of sand body and fast horizontal change and much vertical superposition of sand body in Yingcheng formation ?-?Yingcheng formation of Longfengshan areais a set of near provenance deposit where main rock types are medium-fine conglomerate,glutenite and coarse sand,with coarse particle size and worse separation.Interstitial material mains contains clay,calcite and silicic.Evaluation for rock slice think that main rock types play compaction,cementation and dissolution roles and think that reservoir porosity can be divided into intergranular porosity,vuggy porosity and microporosity with compact and low permeability reservoir,rapid physical change and strong anisotropism.Sedimentary of Yingcheng formation and Shahezi formation possess thick dark-coloured mud rock with good organic matter type,high maturity,which is main source rocks in the research region.Mud rocks in the ? Yingcheng formation and volcanic rocks in the ?Yingcheng formation are two sets of stable cap rocks in the research region.And dual cap rocks are advantage for oil-gas preservation.Formation of trap is controlled by lithology and structure to construct lithology gas reservoir.Good migration of oil and gas gather these conditions as fault,construction and sand body develop well.Based on the above analysis,it is concluded that the thick source rock source in the Shahezi Formation is the foundation,the oil and gas are concentrated near the hydrocarbon generation center,and the distribution of the natural gas is controlled in the area.The inherited faulted noses structure of the southeast slope of the hydrocarbon is favorable for the accumulation of oil and gas.The distributary channel sedimentary microfacies of the delta front control the development of high-quality reservoir,affecting the reservoir physical properties,and controlling oil and gas accumulation,for its filling and storage provides the conditions.The existence of double caprock is a key factor in the preservation of oil and gas reservoirs.