A novel approach to resource potential estimation and field development of non-structural traps with limited data: a case study of Achimov formation in Western Siberia

Background. The West Siberian basin which is one of the main oil and gas regions of Russia is characterized not only by classical structural traps but also by extremely complex geological objects of Achimov sequence. Thereby, it is quite difficult to evaluate perspectives of license areas within which we can discover those Achimov type of deposits, especially at regional stage exploration in terms of a complete absence of 3D seismic data and uneven coverage of area by 2D seismic surveys. Aim. This article is devoted to the methodology description for probabilistic assessment of the resource base of non-structural traps in the Achimov strata in areas with different 2D-seismic exploration degree. Materials and methods. The methodology based on the “density” method which in relation to the evaluated area uses statistics of estimated parameters and number of bodies in the field analogs. The general line of this paper is how to use this methodology for resource base evaluation in the zones of Achimov deposits intersection as the most promising from the point of further development. Results. As part of the project evaluation according to the proposed approach, the resource base was divided into components — resources of objects in areas of possible intersection and resources of single, non-intersecting objects. Conclusions. It provides an opportunity to spot and conduct a technical and economic assessment of previously uneconomic reservoirs.

non-structural traps, lithological traps, Achimov sequence, resource appraisal, gCoS, uncertainty, analogues, resources

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