Geology of the Johan Sverdrup field: A giant oil discovery and development project in a mature Norwegian North Sea basin
Bibliographic record
Abstract
ABSTRACT The giant Johan Sverdrup oil field on the Utsira high in the Norwegian sector of the North Sea is an example of a multibillion-barrel oil discovery in a mature and prolific super basin. After 50 yr of exploration in the region, the field had eluded the oil industry. Wells drilled (from 1967 to 2006) had oil shows in both basement and traditional sandstone reservoir rocks. The first significant discovery in the area was not made until 2007 with the Edvard Grieg field, shortly followed by the discovery of the Johan Sverdrup field in 2010. The mainly Jurassic-aged Statfjord and Viking groups constitute the two principal reservoirs in the field containing reserves in the order of 2.2–3.2 BBOE within a productive area of approximately 200 km2 (∼124 mi2). Reservoir properties are excellent, with multi-Darcy permeabilities. The stratigraphic succession of the area, from Upper Triassic–Lower Jurassic alluvial deposits at the base to Upper Jurassic–Lower Cretaceous open-marine deposits at the top, records long-term subsidence and marine transgression, although interrupted by significant Middle Jurassic thermal uplift. During this time, accommodation was influenced by phases of extension and the creation of oblique-slip faults, previously not described in this region. The resulting stratigraphic architecture provided the basis for one of the largest oil fields in the North Sea super basin and a major supplier of energy for decades to come.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".