Delineation of Mauddud Carbonate Reservoirs in Raudhatain and Sabiriyah Fields of Northern Kuwait Using Seismic Inversion and Porosity Modeling

Mafizar Rahaman*, Bader Al Ajmi, Osman Khaled, Yousef Al Zuabi, and Mohammed Ismail Syed
KOC
*[email protected]

Raudhatain and Sabiriyah fields were discovered during mid-1950s and approximately 500 wells have been drilled over the two structures. The Upper Cretaceous Mauddud limestone is one of the main producing reservoirs in both fields and it has good porosity development, which ranges between 15–35%. In both fields, well-productivity is highly variable due to rapid lateral variation of porosity and permeability. The key challenge is to improve the description of the reservoir and its internal heterogeneity so as to guide infill drilling. Seismic inversion has emerged as an invaluable tool for characterizing the reservoirs and quantifying their properties. It combines geophysical, geological and petrophysical data through a robust inversion scheme to extract more meaningful reservoir information. In this study, the Mauddud carbonate reservoirs in Raudhatain and Sabiriyah fields were used to demonstrate the benefits of deterministic seismic inversion. A relationship between acoustic impedance and porosity was established using well data. It was applied to the acoustic impedance volume to transform it into porosity volume. This porosity volume was then used to generate porosity maps for the Mauddud reservoir interval. The generated map showed additional areas of good porosity development in around both field areas. This study has provided a better understanding of the internal reservoir heterogeneity and facies variation. Moreover it has provided a strong base from which to refine the planning of development, placement of new exploratory wells in and around the structures, and in optimizing the oil production.

AAPG Search and Discovery Article #90077©2008 GEO 2008 Middle East Conference and Exhibition, Manama, Bahrain