LONDON – Ophir Energy says the focus of exploration on its Ntsina and Mbeli concessions off Gabon has turned to the presalt play. Until now, poor seismic imaging has limited exploration of the presalt play in the North Gabon basin, but recent advances now allow effective mapping of presalt traps.
Ophir says seismic and gravity gradiometry surveys have revealed a potentially significant presalt play system in its blocks. The main focus has been over the Padouck Deep prospect which could hold around 1.3 Bbbl.
Across the conjugate margin from Gabon is Petrobras’ Carmopolis field, with in-place reserves estimated at 1.7 Bbbl.
Petrobras has farmed into 50% of both Mtsina and Mbeli, and is funding the cost of a new 2,200-sq km (849-sq mi) seismic survey acquired early this year by PGS, which is intended to image the presalt system. The data will undergo pre-stack depth migration processing.
The pre-salt play has more limited extent southward into Ophir’s Manga and Gnondo concessions, where the focus is on the postsalt stratigraphic section.
Discoveries off Brazil such as Petrobras’ Barra in 2010-11 suggest this play could have analogues in the North Gabon basin.
Ophir has acquired 3D seismic already this year over Manga to assess the potential west of the Loiret Dome, where it has identified stratigraphic onlap plays and leads, one of which - Afo - could be significant. The play system extends into the southern part of the Ntsina block and therefore the 3D survey has continued into this concession.
Processed data should available in early 2013. Once this has been interpreted, Ophir plans to seek a farm-in partner for next-phase work which could lead to drilling during the first half of 2013.