Reservoir Comprehensive Evaluation Of Chang 8₂ Reservoir In The H84 Well Area Of Longdong

H84 well area is in the south weastern of YiShan Slope of the Ordos Basin.The Chang8₂ formation in Yan chang formation of Jurassic is the key horizon with good development prospect in this study.Basing on the existing research data and combining with the theory of the sedimentology,petroleum geology,reservoir sedimentology,etc,the paper is based on the cores desribing,annlysis test data and oil testing data,etc,and it studies strata,structure,sedimentary fades andreservoirof Chang8₂ oil formation.On above basis,the reservoir of Chang8₂ is comprehensively evaluated.The results show that it divided Chang 8₂ fornlation as Chang 8₂¹and Chang 8₂².Distributary channel and underwater distributary channel sandbodies of shallow-water deltas developed.The types of petrology of Chang8₂ oil-bearing layer of Yanchang Formation reservoir in this area are mainly lithic arkose sandstone and feldspathic lithic sandstone.Pore combination of the main types is small pores-micro-jets,and its pore throat connectivity is poor.There also developed many types of diagenesis in this area,it mainly includes compaction,pressure solution,cementation,replacement and dissolution.The control factors of Chang 8₂ reservoir development include sedimentation and diagenesis.The area of reservoir evaluation comprehensive study showed that the reservoir in the area is Class II and Class III reservoir into massive distribution,class I reservoir is developed locally.