Logging Evaluation Method Of Chang 6 Reservoir In Huaqing Oilfield

The Chang 6 reservoir in Huaqing Oilfield is a low-permeability,ultra-low permeability reservoir.Accurately searching for high-quality reservoirs in low-permeability reservoirs is the basis for the development of oil and gas fields.Based on the interpretation model of reservoir parameters,the apparent resistivity augmentation method,double-coefficient intersection chart method,and reservoir logging response characteristics were used to identify oil and water layers in this paper,improved interpretation accuracy of reservoir parameters,provide more accurate evaluation indicators for reservoir evaluation.Finally,choose a suitable evaluation method to comprehensively evaluate the reservoir.Through the above analysis,we draw the following conclusions and understandings:?1?Chang 6 layers of the study area are divided into three layers:chang 6₁,chang 6₂,and chang 6₃,the main developmental sedimentary microfacies are the delta front and half deep lakes-deep lakes;its lithology is mainly dominated by feldspar sandstones,reservoir storage types are mainly intergranular pores,and their physical properties are generally low-permeability and ultra-low permeability reservoirs;?2?Based on the"quadruple"relationship and parameter model of the reservoir,the visual resistance increase rate method is used to identify the oil and water layer,determined the lower limit of the physical property of the reservoir,finally,defined 6.5%is used as the porosity limit,0.06×10^-3?m² as the limit of permeability,determined the lower limit of electrical properties in the oil layer/oil-water layer:RI>5.0,AC>-0.5RI+230.5;RI>5.0,AC>-0.5RI+224.5;?3?The reservoir chang 6₁ and chang 6₂ are distributed and the area is small,the chang 6₃reservoir is more continuous in distribution,the area is relatively larger;the comprehensive coefficient evaluation methods and the grey theory correlation method were used to evaluate reservoir respectively,combined with previous research results to establish qualitative and quantitative reservoir classification evaluation criteria,and ultimately evaluated reservoirs by comprehensive analysis method better.