UKCS: New focus on the Southern Gas BasinP2437 licence. Source: CLNR

UKCS: New focus on the Southern Gas Basin

Shell’s farm-in agreement with Cluff Natural Resources (CLNR) for license P2437 has been finalized.

Shell has completed a 50% farm-in into license P2437 situated in the Rotliegend aged Lower Leman Sandstone play fairway, on the eastern edge of the Sole Pit Inversion.

The Lower Leman Sandstone is the principle and proven petroleum system in the basin with offset fields including Barque, Mimas and West Sole. One discovery has been made on the block (Sloop) which was drilled by well 48/08a-1.

This license hosts the Selene gas prospect which has around 90 MMboe in place, of which about 50 MMboe is hoped to be recoverable.

The Selene prospect is located on the northern limb of the Sole Pit Basin inversion axis and takes the form of a NW-SE elongated closure. The prospect is formed by two south-west dipping fault blocks, truncated at the NW region by De Keyser faults running SW-NE.

Well 48/08b-2 was drilled down-dip of the Selene prospect and was drilled near or on major faults, attributing to its lower reservoir quality than regional trends. During uplift these faults likely transmitted pore fluids saturated with carbonates etc. from Z1 and Z2 directly above the Rotliegendes, which led to both ferroan and non-ferroan dolomite precipitating into the reservoir, resulting in 48/08b-2 to be a classed as a dry well despite seeing up to 4.9% gas peaks in the Leman Sandstone.

Seismic section over the Selene prospect. Source: CLNR Corporate Presentation

This is the second transaction between the two companies, as Shell closed in February this year, the deal for a 70% farm-in in license P2252, Southern North Sea.  This license contains the Pensacola Reef prospect, which holds around 100 MMboe.

The Pensacola prospect is a Z2 Zechstein reef partially mapped on 3D seismic data and is analogous to similar structures identified on adjacent blocks. The reef is 15 km long by 6 km wide and clearly defined on 2D and 3D seismic and builds to more than 200 m above the surrounding Z2 (Hauptdolomite) platform.

Seismic section over the Pensacola Reef prospect. Source: CLNR Corporate Presentation

CLNR keeps the remaining 50% in P2437 and will act as the license administrator until a well investment decision is made. When that happens, Shell will cover 75% of the costs for an exploration well of up to £20.7m.

Chief executive Graham Swindells said: “The UK’s Southern Gas Basin is coming under increased focus currently with several highly material exploration campaigns ongoing around our acreage.

With the farm-in complete, Shell will pay to Cluff, within the next 30 days, the remaining £249,000 of the total £498,000 purchase.