Top Seal Integrity - New Advances in Geomechanical Modeling

Top seal integrity can be affected by many factors including the occurrence of natural fractures as well as the distribution of the present day heterogeneous stress field. While opened natural fractures are known to be capable of significantly promoting the flow of hydrocarbons through the top seal, present day stress distribution can lead to critical leakage in the same top seal during drilling and production when pressure is changed. Therefore, understanding and quantifying the spatial and temporal development of the natural fracture as well as the distribution of the heterogeneous present day stress can have great economic impact in the context of hydrocarbon exploration and production and thus significantly improve decision making and reduce production risks. In this contribution we present preliminary results of the new generation of paleo-stress and present day stress inversion and analysis (Maerten F, 2010) using iBem3D, a numerical tool based on innovative iterative 3D boundary element method (BEM), also called Poly3D (Thomas, 1992; Maerten F, 2010, Ch. 1). We described the method, its benefits and limitations and apply it to an example for both natural fracture and present day stress modelling that lead to a better quantification of top seal integrity.