Comprehensive Evaluation Of Chang6₃Reservoir In Huangling-Zhengning Region In Ordos Basin

As main research object of Chang63reservoir in Huangling-Zhengning region, core sample were selected to analyze a series geochemical test including commom thin section, casting thin section, mercury penetration, scanning electron microscope,X-ray, etc. In combination with logging data, Physical property data and oil test data, a systematic study of the research region was developed on Chang63’s lithological characteristics, pore characteristics, physical characteristics and non-uniform property. The reservoir controlling factor,effective reservoir and developing scale were analyzed,finally evaluated Chang63reservoir comprehensively on the basis of these tests.In Chang63reservoir in Huangling-Zhengning region,the sandstone is mainly composed of lithic arkoses, the cement are mainly carbonate, the cementation types are mainly porous cementation and basal cementation. Secondary pores were developed, especially intergranular dissolved pore, it is also the main type of pore combination. The characteristics of pore structure is large size pore throat,mid sorting, uneven distributed and general connection. The objective interval is low porosity and ultra-low permeability reservoir, porosity and permeability have a better positive correlation, the distribution of them is obviously controlled by the distribution of sand body.The physical properties of reservoir are mainly controlled by sedimentation, diagenesis and pore structure. Thereinto, sedimentation controlled the material basis of the reservoir, diagenesis controlled later reconstruction of the reservoir and pore structure controlled the permeability of the reservoir fluid directly.On the basis of the research of The physical property lower limit and electrical property lower limit, the lower limit of reservoir effective thickness was determined. The controlling of effective reservoir was also be determined according to the interlayer distribution frequency and density. The regularities of distribution and developing scale was cleared in combination with the drill encounter rate and thickness of effective sand body.The standards of Chang63reservoir in research region was established and it can be distributed into four types,each roomage distribution characteristics was determined and provided an important basis for the next step prospecting work.