Austria’s oil and gas company OMV has confirmed a gas-condensate discovery at its Oswig exploration well located in the North Sea but, due to challenges with collecting a full suite of data from the existing wellbore, decided to drill a sidetrack well and perform a drill stem test (DST).
OMV has a 40 per cent interest in the licence PL1100 where the well is located. Its partners are Wintershall Dea Norge (20 per cent), Source Energy (20 per cent), and Longboat Energy Norge (20 per cent).
The exploration well 30/5-4S was spud at the beginning of August 2022, using the Maersk Intrepid jack-up drilling rig, which secured this contract in December 2021.
Longboat informed on Friday that the well was drilled to a depth of 5,003 metres TVDSS targeting the Tarbert and Ness formations. Extensive coring and logging data have been acquired and the preliminary analysis of the data indicates an excellent correlation with the nearby Tune field and the presence of gas-condensate in the Tarbert formation.
The presence of hydrocarbons in the deeper Ness formation is inconclusive at this well location and preliminary gas in-place volumes (GIIP) in the Tarbert formation are higher than the overall pre-drill expectations.
Based on the positive indications to date and the challenges of collecting a full suite of downhole dynamic data from the existing wellbore, a decision has been taken by the joint venture to drill a sidetrack well and perform a DST. The key objectives of the DST are to establish reservoir productivity, detailed fluid properties, and determine the range of recoverable resources, Longboat explained.
According to the company, further operations are expected to take between six and eight weeks to complete and remain subject to the granting of the associated regulatory approvals.
Oswig consists of high pressure, high temperature (HPHT) Jurassic rotated fault block near to the Equinor-operated producing Tune and Oseberg fields. Oswig had a pre-drill gross unrisked mean resource of 93 mmboe making it one of the largest gas prospects being tested in Norway this year.
Several additional fault blocks have been identified on-block which could contain further gross unrisked mean resources of 80 mmboe which would be significantly derisked by a successful DST. The nearby analogue Tune field has produced circa 140 mmboe since production started in 2002.