Abstract: Resource Assessments of the West Siberia Basin

GRACE, JOHN D

Three separate approaches are compared for the estimation and characterization of the volumes of undiscovered oil and gas in the West Siberian basin. Each of these approaches illuminates different aspects of the undiscovered resources of the basin and two of the three methods serve as validation for each other.

The first approach is a mass balance analysis of the Bazhenov-Neocomian petroleum system. This is based on estimation of the volumes of hydrocarbons generated from the Upper Jurassic Bazhenov Formation and the efficiencies of migration, entrapment and recovery. The second approach is an estimate of the oil resources of the central West Siberian basin (the entire sedimentary section treated as a whole unit). This analysis is based on the size frequency distribution of fields found in the basin and the relationship of field size to order of discovery.

The third analysis is a discovery process model applied to the Neocomian and Cenomanian petroleum (condensate and gas) systems of the northern part of the West Siberian basin. These estimates are based on the size-order relationship, but also demonstrate the impact of play definition on assessment results.

All three analyses provide a quantitative foundation for characterizing the size, number, and to a lesser extent, location of undiscovered oil and gas fields in the West Siberian basin. Differences between the results point to the impacts of play and system definitions as well as uncertainties in the analysis.

AAPG Search and Discovery Article #90942©1997 AAPG International Conference and Exhibition, Vienna, Austria