Reservoir Inversion And Target Prediction Of Shahejie Formation In BZ 34-2/4 Oilfield Of Huanghekou Sag

BZ34-2/4 oilfield is located in the central uplift of Huanghekou Sag in Bohai Bay Basin,and has a geologically favorable oil potential.Taking sequence stratigraphy,exploration seismology and reservoir geology as theoretical guidance,this paper correlated the target layer,established the sequence stratigraphic framework thorough logging data and geophysical technology,carried out seismic reservoir prediction inversion,and combined with the characteristics of regional structure and sedimentary facies to forecast the favorable exploration area of Shahejie Formation.In view of the drilling data in BZ34-2/4 oilfield,the synthetic records of single well and multi well are finely generated by using the Landmark workstation software and combining the corresponding relation between the sign layer on the well side seismic track and the geological layering of the well.The inverse Q-filter was used to improve the resolution of the post-stack seismic data in the area.Secondly,the parameters such as DT and GR were used to set up the sensitive parameters for the reservoir.After normalizing the logging parameters and considering the distribution of sedimentary facies,we weighted and normalized the geological constraints.Then,the wavelets were extracted from 25 wells in the study area,which were used to do well-seismic calibration.The initial inversion model was established by the method of inverse distance square weighted interpolation.Finally,the seismic inversion was carried out by using the tuned parameters based on geologic model.Furthermore,the reservoir sand bodies and physical properties were interpreted.The reservoir inversion shows that the thickness of the sand bodies of 9th and 8th layers of the IV oil group in the BZ34-2/4 oilfield varies greatly and spreads from northeast to southwest.The boundary between sandstone and mudstone is quite clear.The sand bodies of the 7th layer of the III oil group are thinner,indicating small lateral difference and wide plane distribution.The 3rd,4th and 5th layers of the II oil group shows thicker in south area and thinner in north area,while layers near 34-4 oil field shows thicker in southeast and thinner in northwest.In the I oil group,the sandbodies of the 1st and 2nd layers are characterized by the flake distribution,and the high values of accumulative thickness is presented with the southeast-north long axis direction.Through the combination of lithologic statistics,oiliness statistics and physical properties,we found the high-quality reservoir(potential reservoir)indicators and identified the reservoir types.Based on the results of sedimentary microfacies,sand body thickness and physical properties distribution,the potential A and B zones are selected by the analysis of reservoir forming conditions with inversion results.