The Reservoir Charactoristics And Oil Reservoir Enrichment Regularity Of Chang6Reservoir Of Heshangyuan Area In Zhiluo Oil Field

Heshangyuan area in the Zhiluo oil field is located10kilometers west of Zhangjiawan Town in Fuxian County of Yan’an City,and the geomorphic unit belongs to the Loess Plateau,and its regional tectonic position is located at the south of Shanbei slope in Ordos basin.The main exploited horizon of Heshangyuan area is Chang21and Chang22.Over years of development,the production capacity of Chang2reservoir has reachde its limits.In2008,Zhiluo oil production plant start to explorate Chang6reservoir,which is supposed with big exploring potential in Heshangyuan area,and Chang6reservoir is the new layer of exploration and development.But,for now,the study in reservoir geological features of Chang6reservoir is not detailed and thorough.So this paper does a study on reservoir physical property,characteristics and enrichment regularity of Chang6oil deposit.This research has important real significance for carrying on scientifical and reasonable hydrocarbon exploration and production,and also for risk reduction and improving efficiency.This paper thinks sequence stratigraphy,reservoir sedimentology,petroleum geology as the guiding ideology.Basing on drilling data,logging data,core analysis data and the existing research results,we carry on study about tectonic characteristics, sedimentary facies distribution,reservoir feature and reservoir characteristics by the methods of reservoir geo-logy,reservoir sedimentology, logging geology and reservoir physicals.Deponding on these research,we can analyze oil reservoir enrichment regularity and main control factors in Heshangyuan area.The results of the study showing:The tectonic of Chang6oil reservoir is western leaning monoclinic as a whole,and it is higher in the eastern part and lower in the western part,which develops relieved nose tectonic in Heshangyuan area.Chang6reservoir is delta front deposition,underwater distributary channel shows NE-SW banding distribution.The reservoir sandstone is mainly grey-dark grey fine-grained feldspar sandstone,with a small quantity of debris-feldspar sandstone.The sandstone experiences diagenesis including compaction, pressolution,cementation and metasomatism,and its diagenetic stage basically entered in the middle diagenetic stage A.The average porosity is8.9%,and the average permeability is0.216x10-3μm2of Chang6reservoir.The pore types of reservoir are mainly original intergranular pore and secondary denudation pore. The reservoir sandstone belongs to IIIb-IVb tape, and it is low-super low porosity and low-super low permeability reservoir in Heshangyuan area.Chang6oil deposit is typical lithologic trap,and its cource-reservoir-caprock combinations is typical the lower-generation and up per-srorage pattern.