A Probabilistic Multi-Scenario Seismic Inversion Scheme for Field Development and Appraisal

Field appraisal and development plans aim to provide the best technical solution for optimizing production and require integration between various disciplines including geology, geophysics, engineering, well planning and environment. One could argue that seismic inversion is the last, and perhaps the most critical, step in the geophysics loop to provide the final deliverables for field appraisal and development evaluations. It is therefore of significant importance to quantitatively assess all the possibilities and incorporate the uncertainties involved in reservoir definition and extension. A probabilistic facies-based seismic inversion method has been utilized to achieve this goal on a recent Central North Sea discovery. The probabilistic nature of the inversion allows one to compute various scenarios. We have categorically selected, amongst others, most-likely, optimistic and pessimistic scenarios based on our prior knowledge and calibration at the wells. Then, we have performed a statistical analysis of all the scenarios to help identifying the uncertainties as well as a post-inversion forward modelling study.