Bibliographic record
Abstract
_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 222035, “Selecting Injected Viscosity in Polymer Flood Projects: A Controversial and Critical Question,” by Eric Delamaide, SPE, IFP Technologies. The paper has not been peer reviewed. _ Polymer injection is now a mature enhanced-oil-recovery process, and numerous large-scale expansions are currently underway while new projects are being designed globally. Some practitioners advocate injecting very high viscosities, while others advocate the opposite. The paper explains why the question of polymer-viscosity selection remains without a clear answer and describes the arguments of both positions using case studies. Paper Scope The complete paper is a comprehensive review of global projects in which the issue of injected-polymer viscosity has been explored by the author in a variety of scenarios and contexts. Because of the detailed nature of the review of these studies, this portion of the paper, which makes up its majority, is not included here; instead, the discussion and conclusions reached by this paper’s author are preserved and included in this synopsis. The aspects of the issue detailed in the complete paper include the following: - Polymer viscosity and recovery factor ---- Microscopic displacement efficiency ---- Areal sweep efficiency ---- Vertical sweep efficiency --------- Multilayer reservoirs with crossflow --------- Multilayers with no crossflow ---- Field experience --------- Monolayer reservoirs --------- Multilayer reservoirs with crossflow --------- Multilayer reservoirs without crossflow - Concentration and adsorption - Injectivity and fracturing ---- When fracturing is not desired/expected ---- When fractures are desired/expected ---- Field cases - In-depth polymer flow ---- Field cases - Surface facilities issues - Operations Discussion This paper discusses the effect of injected-polymer viscosity on various aspects of a project, from recovery to surface facilities. The review includes both theoretical arguments and practical field experience because these do not always align. In theory, increasing polymer viscosity to achieve a favorable mobility ratio is preferable and would lead to the highest recovery, particularly in the case of multilayered reservoirs with crossflow. Increasing polymer viscosity to achieve mobility ratios below 0.1, however, seems difficult to justify. In multilayered reservoirs with no crossflow, vertical sweep efficiency will, in practice, be limited, even with an infinite polymer viscosity, unless significant volumes of polymer are injected. Finally, field experience has shown that increasing polymer viscosity does not always result in increased recovery. In the case of polymer injection, theory can be misleading and should be considered with caution. Discussion on viscous crossflow, and field experience in heavy oil, has shown hidden complexity. Increasing injected-polymer viscosity in heavy-oil fields, as suggested by some authors, ignores the economic realities of heavy-oil operations. Heavy oil is sold at a significant discount compared with West Texas Intermediate, and reducing operating costs is paramount. Increasing injected viscosity did not guarantee an increase in recovery as shown in Tambaredjo and a field case in Saskatchewan, though polymer cost increased significantly. In addition, in western Canadian fields, injection pressure is regulated—injecting 0.5 pore volumes can take almost 20 years. Thus, many factors must be considered besides theory, which is what operators are doing.
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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 | 0.001 |
| 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".