Microbially Induced Calcium Carbonate Plugging for Enhanced Oil Recovery
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
Plugging high-permeability zones within oil reservoirs is a straightforward approach to enhance oil recovery by diverting waterflooding fluids through the lower-permeability oil-saturated zones and thereby increase hydrocarbon displacement by improvements in sweep efficiency. Sporosarcina pasteurii (ATCC 11859) is a nitrogen-circulating bacterium capable of precipitating calcium carbonate given a calcium ion source and urea. This microbially induced carbonate precipitation (MICP) is able to infill the pore spaces of the porous medium and thus can act as a potential microbial plugging agent for enhancing sweep efficiency. The following explores the microscopic characteristics of MICP-plugging and its effectiveness in permeability reduction. We fabricate artificial rock cores composed of Ottawa sand with three separate grain-size fractions which represent large (40/60 mesh sand), intermediate (60/80 mesh sand), and small (80/120 mesh sand) pore sizes. The results indicate a significant reduction in permeability after only short periods of MICP treatment. Specifically, after eight cycles of microbial treatment (about four days), the permeability for the artificial cores representing large, intermediate, and small pore size maximally drop to 47%, 32%, and 16% of individual initial permeabilities. X-ray diffraction (XRD) indicates that most of the generated calcium carbonate crystals occur as vaterite with only a small amount of calcite. Imaging by SEM indicates that the pore wall is coated by a calcium carbonate film with crystals of vaterite and calcite scattered on the pore wall and acting to effectively plug the pore space. The distribution pattern and morphology of microbially mediated CaCO 3 indicate that MICP has a higher efficiency in plugging pores compared with extracellular polymeric substances (EPSs) which are currently the primary microbial plugging agent used to enhance sweep efficiency.
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.
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 it