3-D Geological Modeling of the World’s Largest Siliciclastic Reservoirs: Greater Burgan Field, Kuwait

The late Albian to early Cenomanian Burgan-Wara formations from Southeast Kuwait Greater Burgan field constitute the largest siliciclastic oil reservoir on earth. The sedimentology and stratigraphy is here reviewed in terms of depositional environment and lateral stratigraphic correlation. An updated geological model is built, based on new interpretations that have significant impact on the reservoir management of this giant field. The integration of newly defined core based rock-types and seismic reservoir characterization from a database of more than 1100 wells allowed to characterize the major reservoir heterogeneities and build the first high resolution 3D geological model for the Burgan field.

The Burgan and Wara formations represent 4 third-order cycles, deposited in coastal settings. The variability inherent to the depositional style leads to a complex reservoir scheme. The Lower Burgan is dominated by stacked braided channels representing homogeneous, high quality reservoirs. Higher in the stratigraphy, lateral facies variability and heterogeneities are observed in tidal dominated units. Mud dominated units occur within the Upper Burgan and Lower Wara formations and provide good sealing capacities. Small, laterally strongly variable and heterogeneous fluvio-tidal dominated units are representative of the Upper Wara Formation.

A high resolution 3D geological model of more than 900 million cells is built, based on the new structural and stratigraphic framework interpretations to capture the complexity of the Burgan Field reservoirs. Rock-types are defined, based on more than 900 well logs and core petrophysical properties measurements. The seismic reservoir characterization, focused on inversion techniques and calibrated with the newly defined rock-types provides crucial information on sandstone proportions distribution, especially in areas with lower well control.

The challenge of a fully integrated geomodel for such giant and complex field is here achieved with a specific workflow combining geological, geophysical and reservoir engineering techniques. The final model represents the first attempt to simulate, at high resolution, the largest siliciclastic oil field in the world and provides a comprehensive way to understand the field heterogeneities and behavior. This model will allow best reservoir management and increased oil recovery.

AAPG Search and Discovery Article #90142 © 2012 AAPG Annual Convention and Exhibition, April 22-25, 2012, Long Beach, California