Research On The Reservoir Characteristics And Discussion On Production Impact Factor Of Chang 8 Oil-bearing Formation In Zhenjing Oilfield

The reservoir charaeteristics and production impact factor of the Chang 8 oil-bearing formation of Yanchang formation, Upper Triassic in Zhenjing Oilfield, Ordos basin are systematically studied in this paper, using integrated knowledge and techniques of Petroleum Geology, Reservoir Sedimentology, Petrology, Logging Geology, Petrophysics and Reservoir Engineering, based on various analytical and measurement methods including identification and quantitative statistics of thin sections under microscope, analysis of X-ray diffraction, compute image grain size analysis, compute image granularity and por-throat analysis, electron scan microscope, analysis of physical properties and capillary pressure measurement. This research has the vital significance of understanding intensively factors and mechanisms of the reservoir of low porosity and low permeability in Ordos basin, seeking for more high-quality reservoirs, speeding up the exploration and exploitation of Zhenjing Oilfield, enhancing the exploration effect and economic efficiency, instructing the later drilling and so forth.This study shows that the main rock type of the Chang 8 reservoir is lithic arkose, with feldspathic litharenite as the subordinate ones. The type of pore is mainly vuggy porosity, and primary intergranular pores, relatively undeveloped, is as the second place among the reservoir pores. The main pore texture of the reservoir is very small sized porosity with minuteness throats, small sized porosity with minute throats as the subordinate ones. The reason of lower porosity and permeability is induced by compaction and cementation. The reservoir physical property is improved obviously by dissolution and the growth of micro-crack at some extents. The major controlling parameters on the reservoir heterogeneity are development and distribution of barrier bed and intercalated bed, sedimentary environment, detrital component, diagenesis and pore structure. The sensitivity of the Chang 8 reservoir is mainly strong alkali sensitivity, weak-no salt sensitivity, speed sensitivity and water sensitivity, weak acid sensitivity. The potential parameters on the reservoir damage are detrital minerals, texture of the sandstone, composition of interstitial, pore structure. Production impact factor of Chang 8 oil-bearing formation in Zhenjing Oilfield include sedimentary facies of the reservoir, detrital component of sandstone, composition and mode of occurrence of interstitial, diagenesis involved in inpact on por structure, fracture strike and construction technology.