Abstract: The measured porosity data and the observations of the thin sections and blue epoxy resinimpregnated thin sections show that there exist three anomalously high porosity zones vertically in the Cenozoic reservoirs in the Yuanyanggou area, Liaohe Depression, Bohaiwan Basin. To predict the lateral distribution of anomalously high porosity zones, the diagenetic stages and diagenetic facies has been predicted by digital modeling of the diagenetic parameters, e.g. paleotemperature, vitrinite reflectance, sterane isomerization rate, smectite and authigenetic quartz concentrations in spacetime, respectively. The chosen diagenetic parameters are sensitive to diagenesis and applied to divide diagenetic stages commonly. The anomalously high porosity zones are dominantly formed in the channel mouth bar, braided channel and channel bar deposits in the early diagenetic stage B period to late diagenetic stage A₁ period, and developed dissolution diagenetic facieses. Therefore, the anomalously high porosity zones in the reservoirs could be blocked out by superposing the diagenetic facies maps on the microfacies maps. The anomalously high porosity zone of the Shasan member is mainly located in the middle slope part of the Yuanyanggou area, and extends along the western slope of the Liaohe Depression.

Key words: anomalously high porosity zone, diagenesis, diagenetic facies, diagenetic modeling, Liaohe Depression