The well was drilled to the target formation at 7,310 feet drilled depth in the Nubian sandstone reservoir. The well drilled all of the target horizons and has been electrically logged as per the drilling program.
Unfortunately, no hydrocarbon indications (oil) were encountered in the cuttings, cores or on these logs and the well is in the process of plugging and abandonment.
EWA-3X was drilled to confirm the presence of the hydrocarbon columns interpreted in the Belayim and Thebes dolomites in the EWA-2X well and to drill and test the deeper pre-rift sandstone targets, which EWA-2X failed to do, due to drilling problems.
Notwithstanding the independent Schlumberger interpretation of oil columns in the Belayim and Thebes Formations from the EWA-2X well logs, the EWA-3X cores confirmed that no hydrocarbon columns existed. The EWA-3X cores indicated the unsuspected and highly unusual presence of very large (golf ball sized) nodules of anhydrite/gypsum (calcium sulphate) within the dolomites. These calcium sulphates made up some 40% of the formation in the upper part of the Belayim, for example, and decreased in size and frequency with depth. The anhydrites have a very high electrical resistivity and their peculiar distribution in the rock mimicked exactly the distribution of resistivity expected of an oil column.
Detailed sedimentological studies on the cores are ongoing and discussions have been opened with the Schlumberger team who carried out the initial evaluation work on EWA-2X in 2003 to identify what caused Schlumberger's report to provide results inconsistent with our recent findings.
The severe drilling problems encountered in the EWA-2X well were avoided in the EWA-3X by very careful control of the drilling procedures. Dover was extremely successful in solving the lost circulation problems over this zone. The well was then deepened into the pre-rift sandstone targets of the Matulla and Nubia Formations after securing the problem interval where losses of fluids were occurring by cementing in with casing. However, there were no oil shows in the drill cuttings and no significant gas shows in the Matulla and Nubia. This section of the well was also electrically logged and no indications of hydrocarbons were observed, with all of the sandstone reservoirs being water saturated.
Dover's management is undertaking additional oil migration, magnetic and seismic studies to determine the structure most likely to contain commercial hydrocarbons for potential future drilling in East Wadi Araba (EWA). In that regard, one possibility Dover is considering pursuing is joint venturing with another oil company to drill additional targets.
Most Popular Articles