The Fortuna East-1 (R5) step-out exploration well in Block R, Equatorial Guinea, has successfully encountered gas in the eastern lobe of the Fortuna complex, Ophir Energy announced.

In addition, the well discovered gas in the deeper Viscata exploration target.

The R5 well is 7 km (4 miles) east southeast of the Ophir Fortuna-1 discovery and had three objectives, each of which was successfully achieved: confirm the eastern extent of the Fortuna complex, test the Viscata exploration target, and encounter the laterally equivalent potential reservoir intervals for the Tranquilla and Iambe prospects.

The well encountered a 55 m (180 ft) gas bearing column containing a total 40 m (131 ft) of net pay in the primary target Late Miocene sands of the eastern lobe of the Fortuna complex. The gas quality appears to be consistent with that observed in previous gas discoveries in Block R. Pressure measurements indicate communication between Fortuna-1 and Fortuna East-1 confirming an increased 101 m (331 ft) gas column in the Fortuna complex.

Gross mean recoverable resources for the eastern lobe of the Fortuna complex are 426 Bcf, exceeding pre-drill estimates of 304 Bcf. Confirmation of the eastern lobe will increase the contingent resources (2C) category of the Fortuna complex to 798 Bcf.

Exploration of the secondary target, the underlying mid-Miocene Viscata exploration prospect, was also successful. The well was drilled in a non-crestal position for the Viscata prospect and discovered an 8m gas column within good quality reservoir with a porosity of 21% and a net to gross pay of 48%. The reservoir shares a common gas-water contact with the earlier Fortuna-1 discovery well. The pre-drill estimate for the Viscata exploration target was 359 Bcf. The forthcoming Fortuna West-1 step out exploration well will further define the accumulation and enable estimation of the resource potential of the Viscata discovery.

Fortuna East-1 is the second in the three well Ophir-operated 2012 Block R drilling program in Equatorial Guinea using the Eirik Raude semi-submersible rig. The well spudded on July 2 in a water depth of 1,853 m (6,079 ft) before the rig was moved to drill Tonel-1 (R4). The rig moved back to Fortuna East-1 (R5) on July 29, and the well was drilled to a total depth of 3,465 m (11,368 ft) subsea.

The Eirik Rauderig has now moved to the Fortuna West -1 (R6) location to test the western lobe of the Fortuna complex and the Felix exploration target. Results from this well are anticipated in early September 2012.