The Study On Enrichment Laws Of Oil Reservoirs Of Chang4+5Member In Jiyuan Area

This paper investigates the Chang4+5group of Yanchang Formation in Jiyuanarea,Ordos basin. Make full use of the core, logging and logging data. Integrated thesedimentology and logging geology Closely. Research stratigraphic division,sedimentaryfacies,sand body distribution and reservoir characteristics.Chang4+5reservoir the favorablezone target preferred study area based on analysis of oil reservoirs.The results show that:The Chang4+5oil group of the study area can be divided into sandunit4+51and sand unit4+52,May be further divided into4+511、4+512、4+521and4+522fourmember; The sedimentary facies major for the delta front, and further can be classified asunderwater distributary channel, underwater distributary Bay and underwater natural leveebetween the branch microfacies; Chang4+5reservoir rock types mainly fine-grainedfeldspathic sandstone. The porosity of the main types of intergranular pores, followed byfeldspar dissolution porosity.The mercury curve flat section clearly show that the reservoirbetter sorting. Chang4+5reservoirs is a low porosity-ultra-low permeabilityreservoirs.Chang4+5oil group, according to the the reservoir classification criteria and dataanalysis in this area is mainly Class Ⅱ reservoirs, with a wide distribution, the thickcharacteristics. Reservoir type is mainly of lithologic、structural-lithologic deposit, reservoirenrichment is controlled by the oil source, deposition condition, reservoir, and many otherfactors. The wide distribution of hydrocarbon source rocks oriented area provides a rich sourceof oil accumulation, permeable sandstone and microcrack is the main channel of the oil andgas migration, a large area of distribution of delta underwater distributary channel sand body isthe region’s most favorable reservoir. Finally, according to the characteristics of oil reservoirsanalysis, the The favorable zone preferred target66, forecasting a total area of745.54km2andstorability as26093.9×104t。...