Evaluating quality of 3D geological models: a case study of horizon US2 in the Latitudinal Ob region

Abstract

In recent years, there has been a downward trend in easily recoverable hydrocarbon reserves in the Cretaceous sediments of Western Siberia. In this regard, interest in the horizon US₂ has increased. Collectors of this horizon have a complex structure, which leads to the appearance of significant errors in geological models. The development of the methodological basis for the analysis of the accuracy of geological models, in particular three-dimensional, can solve this issue.

The article gives a technique for analyzing the quality of a 3D geological model: a case study of horizon US₂. As a result of the work, the following conclusions were drawn: firstly, there is the need to update geological models after drilling each well; secondly, the possible causes of the discrepancy between the actual and forecasted indices are revealed; thirdly, usage a map of the residuals of the absolute elevations of the horizon US₂, as additional information, can minimize risks when drilling wells and increase the reliability of 3D geological model.