Joint Inversion of 4D Seismic and Production Data

Abstract

Abstract We present a workflow for the quantitative integration of 4D seismic and production data into reservoir simulation models. Reservoir models are probabilistically history matched to 4D seismic and production historical data simultaneously. The timely incorporation of 4D seismic into reservoir models, coupled with the associated reduction of production forecast uncertainty, has a significant impact in the modern reservoir management of oil and gas fields. One of the outstanding features of the work presented is the use of the 4D seismic data at the seismic trace level (i.e. seismic wiggle) compared to the impedance level. In the joint inversion approach, the reservoir models are jointly calibrated to the production data and the 4D seismic data simultaneously through a single inversion process. There is no need for separate seismic inversion for impedance or for pressure/saturation. The calibrated reservoir models honor both the historical production data and the 4D seismic traces. The joint inversion ensures consistency among the observed 4D seismic traces, the observed production data, and the geological, seismic, petrophysical and flow models. This consistency, while it is guaranteed in the joint inversion, is difficult to attain through the traditional approach of separate inversion processes for 4D seismic and production data. The joint inversion process seeks: a) to shorten the time between 4D seismic acquisition and its incorporation into reservoir models, b) to use 4D seismic in a quantitative way, and c) to reduce uncertainty in reservoir models and thus reduce uncertainty in the production forecasts. This paper presents and discusses results from application of the joint inversion workflow to a synthetic field case based on a real field. The example covers the areas of a) history matching of flow simulation models to 4D seismic and production history, and b) estimation of uncertainty. The joint inversion process requires a multidisciplinary effort. It involves the joint modeling of geology, flow simulation, rock physics, and seismic modeling under a common earth model, and thus it naturally fosters the efficient interaction among geologists, geophysicists, and reservoir engineers.