Reservoir Characterization of the Orinoco Heavy Oil Belt: Miocene Oficina Formation, Zuata Field, Eastern Venezuela Basin
Bibliographic record
Abstract
Abstract The Zuata Field, located on the southern flank of the Eastern Venezuela Basin, produces heavy oil from porous unconsolidated sandstones of the Lower Miocene Oficina Formation. The Oficina Formation is composed of multiple depositional sequences which display complex erosional geometries. This creates an intricate reservoir architecture as younger fluvial systems down-cut, erode and re-distribute the sediments of earlier-deposited systems within each depositional sequence. Superimposed on this intra-sequence complexity is the downcutting and interconnection of sands of different depositional sequences. The Oficina Formation within the study area can be subdivided into eleven depositional sequences. Each depositional sequence has been characterized in terms of environments of deposition and mapped, which has allowed visualization through time of the facies and reservoir geometries. Within sequences, environments of deposition include a mix of fluvial, distributary channel, estuarine, tidal channel, delta plain and coastal plain, resulting in variable net to gross ratios and variable kv/kh. Productive sands are located within incised valleys, usually within the basal part of each depositional sequence, while sediments in the inter-valley areas comprise a combination of older (pre-incision) deposits and thin delta plain / coastal plain deposits. These are variously intercalated siltstones, fine-grained sandstones and coals, and are generally non-productive.
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 | 0.003 | 0.002 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| 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".