Simultaneous Inversion of Production Data and Seismic Attributes: Application to a Synthetic SAGD Produced Field Case.

Abstract : The joint use of production data and time-lapse seismic attributes can help to understand fluid flows within geological formations and to build reliable numerical models for representing these formations. This concern recently motivated the development of dedicated inversion or matching techniques for identifying models consistent with all collected data. The methodology presented in this paper makes it possible to map petrophysical properties such as facies, porosity and permeability into reservoirs from production data and seismic attributes. It is successfully applied to a synthetic case describing a heavy oil field produced from steam assisted gravity drainage. This case study generated from a real case shows how to design the inversion methodology to match the entire set of available data. A few key points are highlighted since they drive the success of the proposed matching methodology. First, parameterization is essential. It must allow for locally varying petrophysical properties from a reduced number of parameters. Second, this study stresses the need for alternative formulations for quantifying the mismatch between reference seismic attributes and simulated seismic attributes. Last, two methods are compared for integrating reference seismic attributes either in time or in depth (after a time-to-depth conversion). In the case studied, it is shown that the two approaches are equivalent since time-to depth-conversion error is quite small.