New Insights into the Amin Formation by the Integration of Basin and Field Scale Data

Raimond C. Van der Pal¹*, John A. Millson¹, Steven G. Fryberger¹, John F. Aitken¹, and Joerg Mattner^2
1PDO
²GeoTech, Bahrain
*[email protected]

As gas operator on behalf of the Oman Government, Petroleum Development Oman (PDO) has been active in a mature basin for about 23 years. One of the focus areas for gas exploration and development in the north has been on deep Haima reservoirs. One of the main reservoirs in the deep Haima is the Early Cambrian Amin Formation. The information in outcrop and from sparse well data provided insights in basin-wide trends and reservoir quality factors for this formation. Information from relatively dense well data in a field development can be used to focus on higher-frequency lateral and vertical variations and the mechanism steering these differences. Outcrop data were tied using core and regional trend maps to the Amin geology in a northern Oman field. Detailed correlation and core evaluation, combined with seismic control, provided new insights in the Amin Formation geology, including: (1) a grainsize trend was observed in core data, (2) erosion at the Amin-Miqrat boundary suggested that sweet spots with reworked sediments may exist in the basin, (3) Apart from the usual reservoir quality factors (depth of burial, facies, contact position), additional factors have been identified including: fault proximity, zones subject to intense deformation, porosity enhancements due to leaching and fracturing. These new insights are being incorporated in the exploration strategy of the basin and in the development approach and modelling of fields. They allow for a better definition of pre-drill risk and recovery effectiveness, as well as more robust production forecasts and well placement.

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