Falklands blocks prospective for oil

May 22, 2009
Rockhopper Exploration has issued new details of prospective resources in its blocks in the North Falkland basin.

Offshore staff

SALISBURY, UK --Rockhopper Exploration has issued new details of prospective resources in its blocks in the North Falkland basin.

A Competent Persons Report (CPR), compiled by consultants RPS Energy, has identified eight potential oil-bearing structures with combined recoverable reserves of around 1 Bbbl.

Of these, the Sea Lion and Ernest structures are the foremost exploration targets, with an estimated 23% chance of success. Rockhopper has mapped a further 15 oil prospects which were not considered for the CPS, as they are unlikely to be targeted in the first round of drilling.

RPS' study also examined Shell's 14/5-1A well, drilled in 1998 in 500 m (1,640 ft) of water in the PL032 license, which identified 165 m (541 ft) of net gas pay. This has now been re-assessed as a contingent gas resource named Johnson – the first contingent resources to be declared in the Falkland Islands area.

It follows Rockhopper's re-interpretation of the well, based on a 3D seismic survey in 2007, which suggests that Johnson is a previously unmapped structural closure.

The CPR also outlines the basis for proven source rocks in the North Falkland basin. Basin modeling in the northern area indicates that gas in Shell's well was generated from Jurassic or Early Cretaceous layers.

Some oil was also recovered, thought to originate from shallower, Lower Cretaceous rock. This source rock is also likely to be mature over a larger area than previously thought, extending just north of PL032's northernmost boundary.

New basin modeling in licenses PL023 and PLO24 reveals further strong potential for source rocks mature in both oil and gas.

Rockwater has submitted environmental impact statements for its licenses, and has completed reprocessing of short offset data on licenses PL032 and PL033 for site survey purposes. Work to date on the Ernest structure has revealed no geohazards.

The company continues to monitor availability of suitable semisubmersible rigs, noting that dayrates have fallen substantially over the past 12 months.