Developing an Outcrop Reservoir Analog for the Williston Basin Bakken Formation with the Sappington Formation of South-Central Montana
Bibliographic record
Abstract
Summary Sappington Formation outcrops of the Central Montana Trough are being developed as a reservoir analog for the subsurface Bakken Formation of the Williston Basin. Correlations utilizing sequence stratigraphy, biostratigraphy (conodonts, palynomorphs, and acritarchs), and geochemistry link the two noncontiguous sections across the intervening Central Montana Arch where the section is not present. These correlations indicate that the variably sandy Middle Sappington siltstone succession (units 2, 3, 4 and 5) is directly comparable to the likewise sandy siltstones of the Middle Bakken. A similar succession of facies allows the complex lateral and vertical heterogeneity that characterizes the subsurface reservoir to be visualized and studied. Although not directly comparable, the overall similar depositional setting and generally similar facies also allows the analog to be extended to the upper parts of the Middle Bakken. Conversely, another key learning is that the Three Forks Formation underlying the Sappington is not a direct analog for the Three Forks reservoirs of the Williston Basin. Similarities extend however to the Saskatchewan part of the Williston Basin and the Alberta Bakken.
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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 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".