Geometrization of East Siberia complex carbonate reservoirs with integration of well-testing and seismic surveys

Abstract

Complex carbonate reservoirs of Eastern Siberia are highly heterogeneous and difficult to predict seismically because of intrusive bodies, thin-bedded strata, and salinization zones. This study aims to evaluate the effectiveness of an integrated reservoir geometrization approach for refining the boundaries of productive zones, improving production drilling success, and reducing geological risks using an oil and gas condensate field in the Irkutsk Region as a case study. The leading method is a retrospective analysis by integrating long-term well testing, interference testing, numerical 2D flow modeling in Kappa Ecrin Saphir, seismic attribute maps (acoustic impedance and Vp/Vs ratio), and seismic facies analysis. The results show that the productive reservoir is only partly associated with basement highs and does not fully conform to their boundaries. By combining dynamic reservoir data with seismic information, the authors define the lateral extent of vuggy porosity zones more accurately. Initial rates, reservoir pressure measurements, and pulse interference tests confirm authors' results. This approach can enhance drilling success from 78,4 % to 86,4 % and provides an effective tool for optimizing well placement and development programs.