Utilizing Natural Gas Huff and Puff to Enhance Production in Heavy Oil Reservoir
Bibliographic record
Abstract
Abstract L Block is a super-deep heavy oil reservoir with the degassed oil viscosity of 9,680∼12,000mPa.s @50☐, 2800∼3300 m deep with normal pressure system and 80∼95☐ in the reservoir. The GOR is 12m3/m3 and the initial bubble point pressure is only 4MPa. High oil viscosity and low flowability result in low production and rapid decline of primary development. This paper will review mechanisms, feasibility and pilot test of utilizing natural gas huff and puff to enhance production in L Block. Firstly, the paper will detail the lab experiments which include the conventional PVT and unconventional PVT. The conventional PVT shows that the natural gas dissolved in the oil can greatly decrease oil viscosity by 1∼2 orders of magnitude and enhance the flowability in one hand, in other hand, it can large the volume coefficient and add the elastic energy. The unconventional PVT shows that the heavy oil can effectively entrap the gas for more than several hours because of its high viscosity. There exists a pseudo bubble point pressure far lower than bubble point pressure in the manmade foamy oil, which is relative to the depressurization rate. Under the condition, the elastic energy could be maintained in a wider pressure scope than natural depletion without gas injection. Secondly, the paper will introduce a special experiment apparatus which can simulate the process of gas huff and puff in the reservoir. The huff and puff experiment shows that in this process the foamy oil can be seen and most of oil flows to the producer in pseudo single phase, which is one of the most important mechanisms of enhancing production. Finally, the paper will brief the pilot test of single well, which shows that the oil production is increased to 5∼6 m3/d from 1∼2m3/d by natural gas huff and puff and the stable production period is prolonged to 91days in the first cycle and 245 days in the second cycle from 5∼10 days before huff and puff.
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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 | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| 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".