Dynamically Constrained 4D Prestack Inversion
T. Blanchard1 and P.D. Thore1
Interpretation of dynamic reservoir properties from 4D seismic data can be difficult in practice due to natural uncertainties in pre-stack seismic inversion and potentially low signal to noise ratios. In this paper we introduce a new dynamic constraint that when implemented in a 4D prestack inversion workflow provides physically coherent elastic attributes.
Analysis of rock physics and petro-elastic models show us that 4D changes in elastic parameters are dependent upon both the 4D effect and the geology. However, we show the combination of elastic parameters is controlled primarily by the dynamic changes occurring in the reservoir, whilst the magnitude of the elastic parameters is controlled by the geological variation as well. Therefore our constraint is designed to only control the combination of elastic parameters, imposing no assumptions about the magnitude of the 4D response. In essence we have a domain that allows us to constrain the dynamic properties of the reservoir, whilst being independent of geology.
AAPG Search and Discovery Article #90188 ©GEO-2014, 11th Middle East Geosciences Conference and Exhibition, 10-12 March 2014, Manama, Bahrain