West Africa is an established oil and gas producing area, and the home of many major oil and natural gas discoveries and producing fields. We operate the Dussafu PSC offshore southern Gabon with a 66.667% working interest over a 680,000 acre PSC.
The license is surrounded by existing producing oilfields to the northwest (Etame), northeast (Lucina), east (M’Bya) and southeast (Yombo) along with other nearby fields. The producing fields in the Etame cluster, located just 30 miles to the north of our operations area and operated by Vaalco, are direct analogs to our Ruche and Tortue discoveries, as well as other structures we have identified on seismic within the Dussafu block.
With our latest discovery on the Tortue prospect, we now have four oil discoveries within the license area, including Ruche, Moubenga and Walt Whitman. Our ongoing exploration efforts are focused on further appraising these discoveries and evaluating new ones. Exploration activity in 2012 consisted of drilling a new exploration well and a sidetrack appraisal well.
In November 2012, we commenced drilling the Dussafu Tortue Marin-1 (DTM-1) exploration well on our Tortue prospect. This wildcat well was drilled to a vertical depth of 11,260 feet and resulted in a new discovery indicated by log and pressure data indicating 42 feet of pay in a 72 foot oil column within the Gamba Formation and 123 feet of pay in stacked reservoirs within the Dentale Formation.
Following the DTM-1 discovery, we drilled a sidetrack well to the southwest to test the lateral extent and structural elevation of both the Gamba and Dentale reservoirs. The sidetrack was drilled to a total depth of 11,385 feet in the Dentale and 10,790 feet true vertical depth subsea, approximately 1,800 feet from the original wellbore and discovered 65 feet of oil pay in the primary Dentale reservoir which had better characteristics than the original vertical exploration well. We were pleased to find several other stacked sands with oil shows. Unfortunately, a tool became lodged in the wellbore, which prevented logging operations that would have collected pressure data to confirm connectivity.
Our plan going forward is to evaluate the commerciality of the field by performing engineering studies on the previously announced Ruche, Walt Whitman and Moubenga oil discoveries along with the more recent discovery at Tortue. We believe this extends the proven fairway for these stacked pre-salt reservoirs and we will continue to process the information obtained to develop a future development plan that offers the best full-cycle rate of return.