Enhanced Carbonate Reservoir Characterization Based on a Dual Constrains Provided by Forward Stratigraphic Modeling and Seismic Inversion

Abstract

A successful exploration well leading to an economically valuable discovery, kick off new challenges for the Appraisal phase and future development of the field, especially in carbonate environment where spatial continuity of facies can be limited. A phase of detailed reservoir characterization is starting, where bringing tools and concepts from exploration at lower scale and higher resolution can add value to classical methods. Reducing uncertainties at appraisal stage of a reservoir is a key challenge to tackle, due to the limited number of exploration and appraisal wells. The prediction of the facies architecture inside complex carbonate reservoirs is another challenging task that cannot be assessed using straightforward classical geostatistics methods. The facies are used as the main guideline to populate the properties of static model, reducing error in facies assignation and propagation in the mesh is mandatory. In such a composite context, a tool able to constrain physically and geologically the sediments spatial distribution is a serious advantage. In this framework, results of 4D Forward Stratigraphic Modeling combined with Seismic Inversion can be a useful tool to assess spatial boundaries of facies, and thus optimize well number and location on a reliable basis. The high resolution reached by stratigraphic modeling in low transport carbonate environment is bringing added value to the coarser resolution of seismic interpretation, and Acoustic Inversion. It is also integrating the very high resolution but spatially irrelevant well information. Thus, a high level of detail regarding the reservoir composition is reached, taking into account sequence stratigraphy principles. Furthermore, the common and coherent features observed by two radically different approaches (Inversion form seismic data, and forward stratigraphic modeling) are strengthening the reliability of both techniques. Observed discrepancies between the two different approaches may result from post depositional events affecting the carbonates sediments, such as compaction, faults and fractures network development, or of course, late digenetic effect and events in case of carbonates fields.

AAPG Datapages/Search and Discovery Article #90217 © 2015 International Conference & Exhibition, Melbourne, Australia, September 13-16, 2015