Statoil spudded an appraisal well on the Tyrihans South find in the Norwegian Sea on 21 September. The Stena Don semi-submersible rig is carrying out the drilling, which is expected to take about one and a half months.
“We hope to prove additional oil and gas reserves on Tyrihans South,” reports Knut Christian Grindstad, vice president in the Halten/Nordland exploration unit in Harstad.
Gas and oil have already been proven in Tyrihans South and North respectively, in 1983 and 1984. The blocks in which these finds have been proven lie in production licences 073 and 091, and are situated 40 kilometres south of the Åsgard field. Water depth is about 285 metres. The well on Tyrihans South will be drilled to between 3,000 and 4,000 metres depth.
“We consider Tyrihans to be an Åsgard satellite, and are contemplating direct subsea tie-back to existing infrastructure on Åsgard,” confirms Mr Grindstad.
Timing of the development will depend on available capacity in the infrastructure and the solution chosen for the sale of the gas.
Licensees in production licence 091 are operator Statoil with 55 per cent, Norsk Hydro (33) and ExxonMobil (12). Licensees in production licence 073 are operator Statoil with 54.67 per cent, TotalFinaElf (33.33) and Norsk Hydro (12).
Stena Don is one of the world’s most modern drilling rigs. Its features include dynamic positioning, which maintains the correct position without the use of anchors.
The rig arrived on Tyrihans from an operation on the Statoil operated Norne field. It will also drill the first exploration well on the Blåmeis structure east of the Norne field later this autumn.