Rockhopper Exploration's Sea Lion well (14/10-2) was spudded on 15th April 2010 and was declared an oil discovery after encountering 53m of net hydrocarbon pay and recovering samples of medium gravity crude oil ranging from 26.4° to 29.2° API. The well was suspended for flow-testing and subsequently flowed oil at around 2000 barrels per day (bpd) in a well test in September 2010.
Since its declaration as a discovery area, the Sea Lion prospect has been appraised with 6 further wells and extensive coring. Additionally, a second well test involving an Electric Submerged Pump (ESP) system and Vacuum Insulated Tubing (VIT) resulted in a stabilised flow rate of 5508 barrels per day during the test, and a maximum flow rate of 9036 barrels per day from the upper Sea Lion sandstones.
In addition to providing more information about the Sea Lion Main Complex (SLMC), the company's penultimate well and respective sidetrack (14/10-9 and 14/10-9z) of the drilling camping confirmed a gas and oil discovery in the Casper target, with 18m total net hydrocarbon pay, porosity of up to 27% and permeability of 232mD. 14/10-9 also penetrated the Kermit sandstone (beneath the SLMC), which was found to be water-wet with oil shows.
Rockhopper's final well drilled with the Ocean Guardian was in PL004b, a licence formerly operated by Desire Petroleum, but now under Rockhopper operatorship with a 60% equity stake compared to Desire's retained 40%; this well (14/15-4) well penetrated four prospects: Beverley, Casper South, Casper and the Sea Lion Main Complex, with a total gross reservoir of 89m and total net pay of 57m. Beverley and Casper South were declared wet gas and oil and wet gas discoveries, with 25.8m and 11.6m of net pay respectively. Meanwhile, the appraisal of Casper and the Sea Lion Complex was considered successful, encountering 2.4m and 8m of net pay respectively. No oil-water contact was encountered. The well was consequently sidetracked (14/15-4z) and 115m of core retrieved to surface for further analysis.
Rockhopper's Ernest and Sea Lion North prospects, drilled in 2010 and early 2011, were plugged and abandoned as a dry well and with oil shows respectively.
Should the Sea Lion Main Complex and surrounding prospects prove commercially viable, Rockhopper Exploration will look to move into a production phase in the coming years and has begun work on possible field development and production options.
Falkland Oil & Gas, who retained a 100% interest in its licences after BHPB relinquished its operatorship, have signed a farm-out option agreement with an industry counterparty which, if exercised, would see that partner farm-in to 25% of all FOGL’s existing licences and contribute accordingly to the costs of the 2012 drilling campaign. Under the terms of the option agreement, the partner would make a $20m cash contribution on completion and a further $20m in 2013.
Borders & Southern have completed well 67/17-1 on its Darwin prospect in the South Falklands Basin. The well, the first to be drilled by Borders & Southern, has been confirmed as a gas condensate discovery, encountering a 84.5m thick sandstone reservoir interval with a net pay zone of 67.8m. Average and maximum porosities encountered were 22% and 30% respectively. The company plans to carry out further analysis into the composition of the recovered hydrocarbon samples in order to better understand the nature of the find. Once it completes Borders & Southern’s Stebbing prospect, Ocean Rig’s Leiv Eiriksson will drill two wells for Falkland Oil & Gas to the East and South East of the Falkland Islands.
Fig.1: The Sea Lion Discovery Area
Fig.2: Location of wells drilled up to January 2012