Ophir Boosts Resource Estimates with Block R Discovery

Ophir Energy plc announced the successful completion of its 2012 three-well drilling program in Block R, Equatorial Guinea. All three wells exceeded pre-drill recoverable resource estimates. The Fortuna West-1 (R6) exploration well in Block R, Equatorial Guinea has added an additional 1.0 Tcf (169 million barrels of oil equivalent (MMboe) of recoverable resources. The well encountered gas in the primary target of the western lobe of the Fortuna Complex, in the secondary deeper Viscata prospect and there is further potential upside in the Felix prospect.


  • Fortuna West-1 (R6) is the sixth gas discovery in Block R. Ophir operates Block R with an 80 percent stake.
  • The well has discovered a total of 1.5 Tcf (255 MMboe) mean in-place resource (1.0 Tcf (169 MMboe) mean recoverable resource):
    • Western lobe of the Fortuna Complex:
      • Estimated mean in-place resource of 516 Bcf (86 MMboe)
      • Estimated recoverable mean resource of 397 Bcf (66 MMboe)
      • Exceeded mean pre-drill recoverable resource expectation of 299 Bcf (50 MMboe) by 33 percent
    • Viscata Channel Levee Complex:
      • Estimated mean in-place resource of 1,012 Bcf (169 MMboe)
      • Estimated recoverable mean resource of 618 Bcf (103 MMboe)
  • The total management estimate of Block R recoverable contingent resources (2C) rises by over 300 percent from the pre-2012 drilling program estimate of 697 Bcf (116 MMboe) to 3.0 Tcf (500 MMboe)


The Fortuna West-1 (R6) well is located 1.86 miles (3 kilometers) SE of the Ophir Fortuna-1 discovery and had four objectives, each of which was successfully achieved:

  • Confirm the western extent of the Fortuna Complex
  • Define the scale of the Viscata discovery
  • Explore the Felix secondary exploration target
  • Test the laterally equivalent potential reservoir interval of the Tranquilla prospect

Fortuna West-1 (R6) encountered a 236-foot (72-meter) gas bearing column containing a total 197 feet (60 meters) of net pay in the primary target Late Miocene sands of the western 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, Fortuna East-1 and Fortuna West-1, confirming the aggregate 331-foot (101-meter) gas column in the Fortuna Complex.

The additional gross mean recoverable resources for the Western lobe of the Fortuna Complex as defined by this well are 397 Bcf (66 MMboe), exceeding pre-drill estimates of 299 Bcf (58 MMboe) by 33 percent. Confirmation of the western lobe increases the total contingent resources (2C) category for the Fortuna Complex to 1,195 Bcf (199 MMboe).

Delineation of the deeper secondary target, the underlying mid-Miocene Viscata prospect, previously encountered in both Fortuna-1 and Fortuna East-1, was also successful. The Fortuna West-1 well was positioned to test the lateral extent of the accumulation and encountered an interpreted 121-foot (37-meter) gas column containing a total of 36 feet (11 meters) of net pay within excellent quality reservoir with an average porosity of 30 percent. The gas column is consistent with a common gas-water contact (GWC) observed within the earlier Fortuna-1 and the Fortuna East-1 wells. Based on this result the estimated gross mean recoverable resources of the Viscata prospect are 618 Bcf (103 MMboe). Further gas-bearing sands were encountered at levels deeper than the Viscata GWC, but given the early stage of the post-well analysis their contribution to the resource base is yet to be determined.

The main reservoir section of the shallower, secondary Felix exploration target was found to be water wet, however thin gas-bearing sands were encountered immediately above the target interval. Preliminary petrophysical analysis shows the sands to be of good quality. Further analysis is required to determine the presence of a possible up-dip gas accumulation.

The well also penetrated the lateral, stratigraphic equivalent interval of the Tranquilla exploration prospect first tested in Fortuna East-1, and confirmed good quality reservoir. This stratigraphic test further de-risks the fore-thrust play across Block R.

Fortuna West-1 is the last in the three well, Ophir-operated 2012 Block R drilling program in Equatorial Guinea using the Eirik Raude (UDW semisub) rig. Fortuna West-1 (R6) was drilled in a water depth of 5,768 feet (1,758 meters) and reached a TD of 10,427 feet (3,178 meters) (MD). The rig is now moving off location.

This three-well drilling program has increased management's estimates of Block R contingent resources (2C) from 697 Bcf (116 MMboe) to 3.0 Tcf (500 MMboe). In addition, the stratigraphic tests of Tranquilla and Iambe have further derisked the remaining inventory of over 10 Tcf (1,666 MMboe) of gas.

Nick Cooper CEO of Ophir said:

"The success of Fortuna West-1 across multiple targets improves our overall understanding of the Fortuna Complex and Viscata Channel Levee Complex within Block R. The well discovered over 1.0 Tcf (166 MMboe) of recoverable gas, and has significantly derisked other exploration targets within the Block. Based on the results of this three-well drilling campaign, we have increased our 2C resource estimate to 3.0 Tcf (500 MMboe), and have reduced the risk on the remaining estimated 10 Tcf (1,666 MMboe) of inventory.

The Fortuna wells combined with the Tonel discovery provide confidence to proceed with commercializing the gas via LNG export. A follow-up exploration and appraisal drilling program in 2013 will further advance this valuable gas asset toward development."


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