Shell appears to have pulled off a significant discovery offshore Norway on the Gro prospect, with the Norwegian Petroleum Directorate (NPD) placing the initial reserves estimate in the range 353.1billion-3.53trillion cu ft of recoverable natural gas.
The NPD said Shell made the find with its wildcat exploration well drilled with the semi-submersible rig, Leiv Eiriksson, on block 6603/12.
That makes the Gro-1 well, drilled in 1,376m (4.500ft) water depth, the deepest of any discovery made on the Norwegian shelf to date. Its objective was to prove petroleum in Upper Cretaceous reservoir rocks, and it encountered a 16m (52.5ft) gas column in the Upper Cretaceous in a reservoir of varying quality.
NPD said the well was not formation-tested, but extensive sampling and data acquisition was carried out. However, further delineation drilling will be required in order to clarify the resource potential, including the possibility of additional volumes.
Now the Leiv Eiriksson is on the South Uist (blocks 213/25a and 214/21a) prospect north-west of Shetland and has started drilling.
Pre-drill estimates point to recoverable reserves of 2.1trillion cu ft of gas (350million barrels oil equivalent) with an upside potential of 4TCF (666million barrels). This is based on Shell’s most recent mapping and interpretation and field parameters from regional analogues,
Data acquired points to a well defined faulted four-way dip closure circa 16km long by 4km wide, with a maximum areal closure of circa 84sq km with potential for a 250m vertical gas column.
Licence P.799 has an area of about 145sq km and is located about 30km (18.6 miles) north of the sizeable Laggan (estimated 720billion cu ft recoverable), 35km (20 miles) north-east of the 2007 Tormore discovery (estimated 320bcf recoverable) and 50km (31 miles) north-east of the recent Rosebank I Lochnagar field (estimated 270bcf and 250million barrels oil equivalent recoverable reserves).
Shell made a previous attempt to drill the South Uist prospect in Q1 2008, but the Leiv Eiriksson failed to complete top-hole operations at that time.
The earlier 214/21-1a well reached about 2,200m (7,200ft) total vertical depth and recorded “positive evidence” for “thermogenic gas generation”. Two gas samples were taken from the top-hole section of that well and the results were seen as “very encouraging”.
Much farther south, on the Irish portion of the Atlantic Frontier, Providence Resources said on June 22 that it had started mobilising a vessel to carry out the long-anticipated Spanish Point 3D seismic survey. This 60-day 3D seismic programme will be carried out using the recently refitted BOS Angler, which will quarter about 300sq km over and around the target, which is already a proven gas condensate find.
The original 35/8-2 Spanish Point discovery well flowed about 1,000 barrels and 5million cu ft of gas per day from one of four logged hydrocarbon-bearing intervals.
Providence says third-party modelling of the well data has suggested that an optimally placed and stimulated development well could flow at significantly higher rates from all hydrocarbon-bearing intervals.
The partners, which also include Sosina and privately owned Chrysaor (which is developing the Suilven field west of Shetland) consider the acquisition of a 3D seismic survey over Spanish Point to be vital in order to further enhance the detailed understanding of the reservoir, as well as to optimise potential future well placement.
The survey, the cost of which is being borne by Chrysaor under its farm-in agreement with operator Providence, has also been designed to accommodate future time-lapse 3D seismic surveying, which has been demonstrated to be particularly effective in monitoring fluid movement during field production.
Tracking north again, at Laggan-Tormore, basic development engineering is being carried out by a joint venture between Offshore Design Engineering (ODE) and Paris-based Doris Engineering under contract to Total.
This contract covers the overall development facilities – subsea production facilities, flowlines, umbilicals, onshore gas treatment plant and export pipeline – and will be executed from ODE’s Kingston-Upon-Thames office by a joint team of ODE and Doris engineers. It is due for completion later this year.
Laggan and Tormore are located in 600m (1,970ft) water depth 125km (78 miles) west of Shetland and will be produced through two subsea production systems about 16km (10 miles) apart.
The development includes up to eight subsea wells connected by two 125km 18in-diameter production flowlines to a new Sullom Voe gas terminal, where the gas will be treated, along with a 125km methanol injection pipeline and control umbilical.
Treated gas will be compressed and exported via a new 230km (143-mile) pipeline to a tie-in point close to Total’s abandoned MCP01 facility and the Frigg UK pipeline (FUKA), and from there on to St Fergus, in the Scottish north-east.
First commercial gas is scheduled for 2013.
Laggan-Tormore is the most significant gas project currently under development in the UK. Expectation is that it will establish major core gas infrastructure and enhance access to hydrocarbon reserves estimated by the Department of Energy and Climate Change (DECC) to account for about 17% of the UK’s remaining oil&gas reserves.
ODE chairman and MD Peter Godfrey said: “This is an extremely important project in a frontier region which draws on the combined strengths of ODE and Doris Engineering.”
UK company ODE is co-owned by Doris and Italy’s Saipem, which is also a significant stakeholder in Doris.
Engineering studies have also been commissioned by BP covering the established Foinaven field. GE Oil & Gas will carry out the work, which covers subsea processing and power-from-shore systems.
The two studies will involve obtaining accurate data for further field development and its technical and commercial feasibility.
The work marks a continuation of work already completed by GE Oil & Gas to support BP in its ongoing quest to further enhance output from Foinaven. Target completion date for the initial engineering studies is Q3 this year. Foinaven is located 190km (118 miles) west of Shetland and was the first field brought into production (1997) on the UK sector of the Atlantic Frontier.