Collaborative Strategy Heightens Efficiency of North Sea Predrilling Campaign

Abstract

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper OTC 30850, “Perfecting the ‘Perfect Well’: Lessons Learned From the Predrilling Campaign for Johan Sverdrup,” by Janne Vølstad and Stian Bærheim, Equinor, and Knut Henriksen, Baker Hughes, et al. The paper has not been peer reviewed. Copyright 2021 Offshore Technology Conference. Reproduced by permission. The predrilling campaign for the Johan Sverdrup development was a key contributor to the successful execution of the first phase of the megaproject. After a summary of the results of the campaign, the focus of the complete paper is to identify some of the key factors behind the success of the campaign and outline lessons learned relevant to future drilling campaigns. Since the completion of the predrilling campaign, the project has successfully tied back, completed, and begun production of eight predrilled oil producers and injection in 12 subsea injectors. Johan Sverdrup Field The field is approximately 150 km west of Stavanger in a water depth of 110–120 m. The top reservoir is situated approximately 1800 m below mean sea level. The reservoir features hydrostatic pressure and undersaturated oil with a low gas/oil ratio. The field has been developed in two phases. Phase 1, approved by Norwegian authorities in 2015, includes four bridge-linked platforms (Fig. 1). These platforms include a living-quarters platform (LQ) with utility system functions, a process platform (P1), a drilling platform (DP), and a riser platform (RP) with tie-in of onshore power. Phase 1 includes three injection templates tied back to the RP. All platforms have jacket substructures. Main power to the field is supplied from shore. The full field development includes 64 wells, both platform and subsea. The field came onstream in October 2019. Ramp-up of the predrilled wells went smoothly to a field production level of approximately 350,000 B/D. Phase 2 of the development was approved in 2019 and is expected to begin production in Q4 2022. Phase 2 includes development of another processing platform (P2), modifications of the RP and the field center, and five subsea production and injection templates. At peak, this field will account for approximately one-third of all oil production in Norway. Expected recoverable reserves are 2.7 billion BOE. The full field (Phase 1 and 2) expected oil production capacity is 105,000 std m3/d (660,000 B/D) at peak. Breakeven price for the full-field development is less than $20/bbl.