Numerical Techniques Used for Predicting Subsidence Due to Gas Extraction in the North Adriatic Sea

Abstract

Abstract This article describes the assessment and application of numerical techniques required for predicting gas production induced subsidence in the North Adriatic. Due to the complexity of the reservoir description and compaction mechanisms, the subsidence modeling required the combined use of reservoir and geomechanical simulators. Extensive validation of the modeling techniques was undertaken, including the level of coupling between the fluid flow and geomechanical solution. It was shown that a fully coupled solution impacted only the aquifer area, and accurate results could be obtained by an explicitly coupled technique. Other issues of importance discussed include quality control of the mesh generation, mesh compatibility, and correct interpolation of variables between the two modules. Finally, we discuss the impact that small overconsolidation (threshold) effects may have on the extent of the subsidence bowl.