Modeling of Subsidence and Reservoir Compaction under Waterflood Operations

Abstract

A full-field, three-dimensional (3D) computer model has been developed to numerically simulate reservoir compaction and surface subsidence for a weak, water-sensitive, hydrocarbon reservoir during field-wide water-injection operations. The developed model was used for modeling the compaction and subsidence processes under waterflood operations at the Ekofisk Field in the North Sea. The model was thoroughly validated through the comparison of model results to extensive field measurements with good agreement being achieved. The validated model has been successfully employed as a tool to forecast subsidence and to assist in the development of a subsidence risk assessment. For practical field applications, important quantitative information, that includes reservoir compaction, seafloor subsidence, and seafloor horizontal movement, may be generated from the full-field, 3D model and is presented in this paper.