Reservoir Evaluation And Distribution Regularity Of Chang 6₃ Oil Reservoir Group In Heshui Area

This research mainly focuses on Chang 63 reservoir property of the Ordos Basin in Heshui region. The research process is based on drilling core, wireline logging data, and combing with conventional porosity and permeability data, casting thin sections, scanning electron microscope, grading analysis, x radial diffraction and conventional mercury injection. On the basement of oil and gas accumulation discipline, combining with practice evaluation to analyze reservoir sand distribution and it development characteristics. The research aim is to clear oil and gas accumulation main controlling factor and to set up optimizing favorable region of the reservoir assessment.The research indicates Chang-63 sandstone formation in research area sedimentary formation is turbidity channel of slumping turbidite fan deposit system. Sedimentary rock is mainly greyish-green and brown grey fine grain arkose and feldspar lithic sandstone. Which with low compositional maturity and textural maturity, the average porosity is 10.25% and average permeability is 0.22 × 10-3μm2, is a typical low porosity- low permeability reservoirs.The Diagenetic of Chang 63 reservoir including compaction, cementation, dissolution and so on, The Diagenetic Facies Pattern can be divided into four kinds, carbonate-cemented, hydromica-cemented, hydromica-cemented and feldspar corrosion, chlorite cementation and feldspar corrosion. Among these factors compaction and cementation is the main reason leading to tight reservoirs.The main kinds of reservoir space were feldspar dissolution pores and residual intergranular pore. Overall for the hole- fine throat reservoir with complex pore structure and strong heterogeneity.According to effective thickness, displacement pressure, Porosity, Permeability, divided the reservoir into high-quality reservoir, general reservoir and non-reservoirAnalysis of key factors through reservoir and hydrocarbon accumulation of research, combined with research area deposition, structure, physical properties and diagenetic features a comprehensive evaluation of equal classification, two blocks of preferred built areas, two blocks of replacement area, and one block of potential area.