Improving off-structure carbonate reservoir characterization using integrated Shared Earth Approach and Forward Stratigraphic Modelling: The Marrat Fm of southern Kuwait

Abstract

A high-resolution reservoir characterization workflow is applied to assess the off-structure prospectivity of Lower Jurassic complex carbonate reservoirs of the Marrat Formation in the southern part of The State of Kuwait along the Dharif-Abduliyah fields. A detailed sedimentological and petrophysical assessment was integrated with 3D seismic interpretation and delineated vertical and lateral facies changes within the fields, which are affected by sets of complex fault patterns. Carbonate geo-bodies have been mapped using seismic stratigraphy, and 3D multi-seismic attribute and seismic acoustic inversion workflows. The Middle Marrat has been subdivided into 5 units (Middle Marrat 1-MM1 to Middle Marrat 5-MM5) that show vertical and lateral lithological and facies variability. The developed integrated sequence stratigraphic framework permitted to better assess the influence of accommodation variations as well as carbonate ecological settings on sedimentary facies development. This framework pointed to the influence of marine incursions and subsequent flooding surfaces, on the development of wackestone to mudstone textures interbedded within porous grainier inner ramp/shoal reservoir intervals. This integrated Shared Earth Approach that combined the various multi-disciplinary and multi-scale results was supported for the first-time by high resolution Forward Stratigraphic Modelling to provide a mapping and identification of petroleum systems elements including potential reservoir locations and baffles as well as stratigraphic trapping mechanisms. This workflow opens a new perspective to increasing hydrocarbon reserves along the Dharif and Abduliyah Fields as well as many other fields along the State of Kuwait.