Integrating 3D Seismic in Multidisciplinary Reservoir Modelling Projects
Authors: Jourdan Charles A. , Ekern Tor Erling 
Published: October 2008

The current position within appraisal and production reservoir modeling is reviewed with respect to the data input, work processes and overall philosophy necessary to achieve optimal, economic hydrocarbon recovery. Modern applications of 3D seismic and time lapse (4D) seismic are making increasingly significant contributions to the generation and verification of dynamic reservoir models incorporating the required levels of geological realism. Reference is made to examples from the North Sea and Norwegian Shelf to illustrate how these seismic data are being used to optimise structural and stratigraphic mapping, rock property mapping, identification of reservoirheterogeneities and the determination of fluid distributions with time. However, due to the uncertainties involved in data acquisition and processing and the inherent subsurface complexity caution should always be exercised when applying the results of seismic studies. This to avoid invalidating the model being constructed. The potential for the seismic conditioning of stochastic geological models and the use of marine shear wave data is also considered.

Introduction

During the last 5-10 years there has been a great improvement in reservoir modelling, both in the techniques being applied and in multidisciplinary relationships]. Today reservoir geoscientists and engineers working within the sphere of reservoir management are getting closer to the total product (Fig. 1) in which:the latest, relevant technology has been applied and the results integrated with those of the other disciplinesgeological realism exists within the reservoir model and the important reservoir heterogeneities have been correctly taken into account (both of which are dependent on significant experience tlom studying good land exposed analogues)iterative processes have ensured consistency and better history matching of model simulationsuncertainty has been reduced and quantified at each stage and carried through to the final product giving a better decision basisdata flow has been smooth and effectivethe results fullfill requirements with respect to business goals and timing.

This despite the ever present demands for faster results and reduced use of human and financial resources.

In high cost areas such as the Norwegian Shelf successful reservoir modelling / reservoir management projects are dependent upon ‘pragmatic’ experts and ‘specialist’ generalists being brought together at an early stage in an integrated team. Experience shows that the models developed should have the right blend of deterministic (use what we think we know) andstochastic (allow for the uncertainty) input. Stochastic modelling has played a particularly importantrole in binding the individual disciplines together and is an effective vehicle for better determining uncertainties, mapping the effects of heterogeneities, reaching a more rapid history match and quicker ‘repairs’ ofreservoir models. In Fig. 1 no clear boundaries are shown between the disciplines in an attempt to get away from the idea of a rigid sequentiality that has previously existed in modeling projects.