Comparison of Probabilistic and Forward Modeling Workflow Approaches for Integrating 4D Seismic Into Reservoir Models: Application to a North Sea Reservoir

Caers, Jef¹, Scarlet S. Castro¹, Hilde C. Meisingset², Trond Hoye², Perrine Gomel², Eli Zachariassen² (1) Stanford University, Stanford, CA (2) Norsk Hydro, Bergen, Norway

The ultimate goal of reservoir modeling is to obtain a model of the reservoir that is able to predict future flow performance. Achieving this challenging goal requires the model to honor all available static (well log, geological information and 3D seismic) and dynamic (4D seismic and production) data. This paper presents a general methodology and workflow for reservoir modeling that integrates data from multiple and diverse sources, using a probabilistic approach addressing the possible inconsistency and/or redundancy between various data sources. The main contribution of this paper is the inclusion of 4D seismic data, which has previously not been accounted for within this workflow. 4D seismic data not only helps monitoring pressure and saturation changes in the reservoir due to production, but also identifying the facies where those changes are occurring. Two general approaches can be followed to include 4D seismic data into the reservoir modeling workflow. The first approach consists of matching 4D seismic along with historical production data; and the second approach consists on modeling the information content of 4D seismic through a spatial probability of facies occurrence (similar to integration of 3D seismic). This paper presents the methodology followed to incorporate 4D seismic data using the two proposed approaches, as well as the application of each of them on a prominent reservoir located in the North Sea.