Study On Logging Evaluation Method Of Shallow Heavy Oil Reservoir In The South Of Daqing Placanticline

With the further exploration and development of oilfield, complex hydrocarbon reservoirhas been one of the main research direction of oilfield exploration. In this paper, the keyobject of the study is the shallow heavy oil reservoir in the south of Daqing Placanticline. Inthis area, heavy oil reservoir usually shallow burial depth, thinner effective thickness and it isdifficult to recognition fluid property.Based on rock physical experiment,coring data, well testing Data and well loggingdata,the characters of lithology, physical property and pore structure in this area are reseachedby using statistical methods,and the analysis results shows that the heavy oil formation hascharacters of mainly siltstone in lithology, high porosity, high permeability, higher irreduciblewater saturation. Utilizing coring experiment data of the shallow heavy oil reservoir in thesouth of Daqing Placanticline, established parameters interpretation models,such as shalecontent, porosity, permeability and irreducible water saturation. Based on the characteristic ofthis area reservoir, with the deep analysis on heavy oil property, comprehensive consideringthe influence of wettability on rock electricity and the influence of conducting components ofshale, irreducible water and free water on conductance mechanism of the reservoir,theconnectivity model based on wettability in the shallow heavy oil reservoir in the south ofDaqing Placanticline is established with the connectivity theory and the mixing law. Throughanalyzing effects of some facters on the proposed model, found the influence of CEC,resistivity of formation, irreducible water saturation,conductivity exponents and the ratio ofoil-wet surface and pore surface on rock conductance rule,and also found that formationresisitivity decreases when the rock varies from water-wet to oil-wet. On the basis of waterconnectivity correction index in the model, established the qualitative indication method ofrock wettability.After processing some log data by using the connectivity model based onwettability, the processed results of model are consistent with core analysis water saturationin sealed coring well and well test results. Te results show that the connectivity model basedon wettability can be well applied in logging interpreting evaluation of sallow heavy oilreservoir in the south of Daqing Placanticline.