LONDON – Falkland Oil and Gas Ltd. (FOGL) has discovered gas in the Loligo structure in northern East Falkland basin.
Results from well 42/07-01 also demonstrate that Loligo is a viable stratigraphic trap. The main hydrocarbon phase within the T1- to T5-aged reservoir objectives is gas, although it is unclear whether there is any liquid content.
The well was drilled to 4,043 m (13,264 ft), and penetrated six Tertiary-age reservoir objectives on prognosis, namely the T1, T1 deep, T2 (Trigg), T2 deep (Trigg deep), T3 (Three Bears), and T5. All had been identified based on seismic amplitude responses.
Strong gas shows were encountered while drilling through each of these horizons. Analysis of wireline log data indicates that all six targets comprise fine grained sandstones, siltstones, and claystones, probably deposited either outside, or at the distal (outer) end of the slope channel system.
Gas-bearing zones were encountered over a 1,300-m (4,265-ft) vertical interval from 2,420 to 3,720 m (7,939 to 12,204 ft). Petrophysical analysis of the intervals between 2,420 and 2,885 m (7,939 and 9,465 ft) indicate porosities of 18-35% in the gas-bearing zones.
Attempts to obtain pressure data and to collect fluid samples were unsuccessful, probably due to the fine grained nature of sediments in the gas-bearing zone. Also, the rig did not have access to test equipment for this type of formation.
FOGL plans to determine the reservoir potential of the thin bedded sandstones and siltstones using detailed petrophysical evaluation, following analysis in the UK of the sidewall core samples. These should help define the work required to further appraise the discovery.
FOGL intends to P&A the well. The company and its partner Edison will drill the next well on the Scotia prospect in the Mid Cretaceous fan play.
Tim Bushell, CEO of FOGL, said: “The initial results of the Loligo well are encouraging. They have demonstrated that hydrocarbons have migrated into the Tertiary channel play. It is also clear that Loligo is a valid trap that contains multiple gas bearing zones, with over 100 m [328 ft] of hydrocarbon bearing reservoir. We now need to focus on reservoir distribution within Loligo in order to find the sweet spots…
“With our partners Noble Energy and Edison, we have the technical resources and funding in place to carry out substantial 3D surveys, followed by further drilling in 2014.”