How to Recover the Petrophysics Hidden into Seismic - Effective Application to an Ultra-deep Offshore Turbidite Reservoir

A multidisciplinary reservoir study of an offshore field in ultra-deep water environment demonstrates how effectively seismic can be integrated within a reservoir modelling workflow to reveal the hidden petrophysical properties. This workflow consists of well data modelling, statistical rock physics modelling, probabilistic petrophysical seismic inversion and geological modelling, and allows to manage reservoir uncertainty in a scenario of few wells. A log-facies model based on petro-elastic characterization is used as common input to seismic inversion and geostatistical simulation processes. A rock physics model, which is later embedded in the seismic inversion, links petrophysics and impedances in a statistical way on a log-facies basis. The conditional probability of petrophysics given the seismic is obtained by means of seismic inversion and rock physics model, which finally provides, together with cluster analysis, the conditional probability of the facies given the seismic. All the uncertainties are handled and propagated to the 3D geological model. Seismic facies probabilities are directly integrated as a prior trend into geostatistical simulations of reservoir properties in order to recover, from the well data, the high frequency part of signal, which is not carried from seismic.