Elastic Parameters Estimation Using Reservoir-Oriented Joint Migration Inversion for Norwegian Sea Field Data

Abstract

We present the first field data application of the full reservoir-oriented joint migration inversion (JMI-res) workflow to estimate the reservoir elastic parameters. JMI-res first reconstructs the fully redatumed data (local impulse responses) at the target reservoir level, while correctly accounting for interbed multiples and transmission losses from the overburden and then applies a localised FWI on the estimated impulse responses to get the reservoir elastic parameters. With this approach, we avoid the need to apply a full elastic process for the whole subsurface. In this paper, we show that JMI-res provides reliable local target impulse responses, thus yielding high-resolution elastic parameters, compared to a standard redatuming process based on time reversal, courtesy of proper handling of interbed multiples and transmission losses in the redatuming step. Even for cases where there are no clear interbed multiples cross-cutting the reservoir, the improvement can be substantial due to recovered transmission losses in the overburden.