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According to the special geologic conditions of some regions in the Liaohe basin, such as complex structure and rapid lateral change of thin interbeds, the technique of logging constrained seismic inversion based on prestack high-resolution seismic data was used in the description of oil-gas reservoirs.
Based on the role of logging data in the inversion, poststack inversion includes 6 types: direct seismic inversion (track integration processing), logging constraint seismic inversion, seismic-logging joint inversion, seismic constraint logging inversion, model constraint random lithologic inversion, and wave impedance inversion in the case of nerve network training. According to implementation approaches, it can be divided into recurrence inversion and model-based seismic inversion.The logging constraint inversion can preserve basic features of seismic reflection. The wave impedance solved by the method has good stability in horizontal and vertical directions and can easily implement constraint conditions. Hence it overcomes the multi-solution problem of inversion, and is able to reveal spatial variations of lithologic phases and lithologic characters. In the case of relatively stable lithologic characters, this method can exhibit changes of physical property of reservoirs.To strengthen the fine assessment of hidden reservoirs of Shasi member, we have made a further seismic inversion by using presatck time migration and high-resolution data. These high-resolution seismic data can accurately reveal the inner features of Shasi sandstone reservoirs and buried hills. On the other hand, the structural configuration displayed by these data is greatly different from that of routine data processing. Therefore, based on the fresh structural interpretation and assessment using high-resolution seismic data, we conduct a study of high-reolution impedance inversion and reservoir prediction to the focused areas. The impedance interferences from mudstone compaction and isochronous sediment interface have been suppressed to some degree.
A logging multi-attribute inversion of acoustic equation of time has been applied to the Shasi member of strata. By utilizing the visualization technique, we have extracted and calculated the inversion results and made the final prediction of all existing sand bodies in the work area.
This work studies the wave impedance inversion of high-resolution presatack seismic data and logging multi-attribute data inversion, which are applied in the Liaohe Oilfield. As a result, the vertical resolution of reservoir prediction is raised, the ability of identifying thin-interbed sand bodies is enhanced, the reliability of reservoir prediction is improved, and favorable lithologic traps of this area are further confirmed. These effects are of significance for exploration of hidden hydrocarbon in this oilfield.
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