VAPEX, Warm VAPEX, and Hybrid VAPEX-The State of Enhanced Oil Recovery for In Situ Heavy Oils in Canada
Bibliographic record
Abstract
Abstract VAPEX, warm VAPEX and hybrid VAPEX rely on a combination of mass and heat transfer to reduce the heavy oil's viscosity sufficiently for it to flow via gravity drainage to the production well. In the last couple of years many combinations of vapour extraction and steam assisted gravity drainage have been proposed for the in-situ recovery of heavy oil and bitumen. The question still remains; which technique (VAPEX, warm VAPEX, hybrid VAPEX and/or SAGD) produces more oil with better sweep efficiencies? This paper attempts to define and compare the various enhanced heavy oil recovery techniques including different solvent choices. The pore scale mechanisms are identified, key advantages and disadvantages given and the results from simple laboratory experiments are compared to better direct the investigation into the in-situ recovery of heavy oil and bitumen. The solvents and solvent mixtures (in combination with non-condensable gases and/or steam) are analyzed based on their physical properties at laboratory and reservoir conditions and the role they play at the pore scale. Introduction Canada's heavy oil reserves are found in western Canada, mainly in Alberta and Saskatchewan. The geographic location of the reserve is indicative of the quality of the oil based on geology. The oil deposit is generally shallower and the oil's viscosity higher (with a lower °API density) the further east and north it is found. The oil found at the surface and below, is in thin shallow sandstone and unconsolidated sand. The porosity ranges from 26–32% and the permeability from 1200–7500 mD (Dusseault, 2006). The current producing fields are found at the surface to a maximum depth of 800–1000 m, have a reservoir temperature from 4–40 °C, and the oil's viscosity from 500 cP to greater than one million. Cold production of heavy oil is possible but production rates are low, sand is often produced with the oil (not necessarily a disadvantage), water cuts are generally high and recovery factors marginal. Cold production is still a logical choice for fields with lower viscosity oil. Otherwise, in-situ heavy oil and bitumen can be produced using enhanced oil recovery techniques (EOR). Canada is the world leader in developing EOR techniques for heavy oil production. New techniques and combination of techniques are constantly being investigated and compared where the ultimate goal is to maximise oil recovery. Steam assisted gravity drainage (SAGD), cyclic steam stimulation (CSS), in-situ combustion, and vapour extraction (VAPEX) are all EOR possibilities. Combinations of VAPEX and SAGD are also being explored and re-examined. This paper strives to give the history of VAPEX, warm VAPEX, and hybrid VAPEX and then focuses on comparing and analyzing the different methods, highlighting advantages and disadvantages, as well as, pore scale mechanisms in VAPEX. The History of VAPEX, Warm VAPEX and Hybrid VAPEX VAPEX or vapour extraction is the process of injecting a solvent into a heavy oil reservoir (through an upper horizontal well) to reduce the viscosity of the heavy oil via mass transfer.
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 distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".