UK oil & gas player buying West of Shetland assets

UK-headquartred energy company Viaro Energy, through its wholly-owned subsidiary RockRose Energy, has executed a share purchase agreement with Spark New Energies Limited (Spark) for the acquisition of Spark Exploration UK, which will enable it to add a batch of assets located West of Shetland to its portfolio.

Map of the acreage position in the West of Shetlands; Source: Spark New Energies

According to Viaro Energy, the acquisition of Spark Exploration UK (P2412) Limited, which holds a 50 per cent interest in licence P2593 located West of Shetland, entails a 50 per cent interest in the Tuck gas appraisal opportunity, estimated to contain prospective recoverable resources of 87 mmboe net to Viaro’s interest and a 50 per cent interest in each of the Boulmer, Cherry and Sammy exploration prospects, containing estimated prospective recoverable resources totalling 280 mmbbls net to Viaro’s interest.

Francesco Mazzagatti, CEO of Viaro Energy, commented: “We are delighted to announce this additional acquisition, which further proves our commitment to the North Sea basin and energy security of the UK. The acquired assets nicely complement our existing production from the Greater Laggan Area, and in the event of a successful appraisal drilling programme, we would evaluate a tie-in to the GLA.”

Viaro said on Wednesday, 1 March 2023, that the transaction value was undisclosed by both parties. The company highlights that Tuck will be developed first, with initial net capex to Viaro, being estimated at £208 million to reach first gas by 2028.

The Tuck gas project is an appraisal opportunity of a gas accumulation proven by the well 206/11-1 within Upper Cretaceous sandstones on the flank of the Rona Ridge. Spark New Energies claims that this region is a prolific hydrocarbon province with significant oil and gas production, as gas production greater than 40 MMscf/d from similar-aged reservoirs is ongoing at TotalEnergies’s Edradour field approximately 50 km to the northeast.

Tuck 3D perspective Seismic inversion high gas probability area in red; Source: Spark New Energies
Tuck 3D perspective Seismic inversion high gas probability area in red; Source: Spark New Energies

Based on the firm’s data, a 3D seismic amplitude anomaly is associated with the reservoir interval at the Tuck gas project to the southwest of the 206/11-1 discovery well, which flowed gas to surface. In addition, a 3D seismic inversion study was completed over the Tuck gas project in 4Q 2021 and concluded that the observed 53 km2 seismic anomaly is consistent with thick, porous sandstones with a high probability of gas fill.

Furthermore, Spark New Energies explains that the downdip extent of the high probability gas sands identified by the inversion study is structurally conformant, which further increases confidence in the presence of gas in the trap.

On the other hand, the Boulmer prospect is a combination structural-truncation trap containing Devonian reservoir sandstones located in the centre of licence P.2593, located 5 km to the southwest of the BP-operated Clair field, which is one of the largest oil fields on the UK Continental Shelf with a footprint of 220 km2 and an oil column of over 700 m.

Moreover, Spark New Energies points out that the Boulmer prospect has been mapped on high-quality 3D seismic data as “a robust three-way structural closure.” The Devonian reservoir sequence onlaps the Lewisian basement topography and is truncated to the southwest by the near Base Cretaceous Unconformity.

Boulmer Prospect 3D seismic line and structure map; Source: Spark New Energies
Boulmer Prospect 3D seismic line and structure map; Source: Spark New Energies

The company elaborates that the absence of the Devonian package to the southwest is confirmed by the well 205/20-1, which penetrated Jurassic sediments sitting directly on the Pre-Cambian basement, which forms the side seal for the trap. This is extremely tight with no open fractures in the core cut in 205/20-1 while Jurassic and Cretaceous shales form the top seal for the prospect.