Arifjan Discovery, a Boost to Jurassic Exploration in Southeastern Kuwait: Learning from the Interplay of Elements Leading to Commercial Discovery

Ahmad Al-Eidan*, Sunil K. Singh**, Nikhil C. Banik, and Meshal Al-Wadi
KOC
*[email protected]
**[email protected]

A detailed analysis of an unsuccessful Jurassic well, located in the northern part of the Ahmadi Ridge in Kuwait, identified the missing link that explained the absence of hydro-carbons at a crestal point in the structure. The knowledge acquired from the dry hole was used to identify prospective areas and resulted in the Arifjan well discovery. Located to the east of Burgan field, the Ahmadi Ridge is a narrow NS-trending anticline with an high-gradient slope to the east. The Arifjan structure is located along the southern part of the Ahmadi Ridge, which is separated to the west from the Burgan Dome by a well-defined but intermittent low. Various play elements, such as entrapment, seal, reservoir quality, migra-tion pathway and a host of other factors, were reviewed for the Ahmadi Ridge. The analysis suggested that these play elements were consistent with the pre-drill prospect analysis. However, the absence of salt within the Gotnia section and extensive fracturing in the over-lying Hith and Gotnia anhydrites were identified as possible causes of seal failure; other evidence also corroborated seal failure. A process was used to identify key aspects for hy-drocarbon-bearing structures in similar settings in Kuwait. The process was applied to the Ahmadi trend resulting in a focused exploration effort on the Arifjan prospect. This process down-played major structural culminations that exist in the northern part of Ahmadi Ridge because of seal risk. Detailed seismic mapping also identified several EW-trending strike-slip faults that intersect the Ahmadi Ridge. These faults segment the structural high trends into several blocks that define multiple structural traps. The commercial success of the ex-ploratory well in the Arifjan structure in the Middle Marrat reservoirs opened a large area for this trend, which was previously considered low in prospectivity.

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