Investigation of Penetration and Plugging Performance of Cement Blends Used for Squeeze Cementing in Sub-150 µm Gaps
Bibliographic record
Abstract
Summary Squeeze cementing is one of the most common techniques used to remediate well integrity issues. Understanding the mechanisms controlling cement particle penetration and/or bridging as well as assessing the potential of cement blends in narrow gaps is important for the design of a successful squeeze cement job. The main objectives of this study are to determine the penetration potential of different cement blends, determine the critical gap width where bridging of cement particles starts, and compare the fracture conductivity of the sample before and after remediation. Four different cement systems were tested for their ability to penetrate and plug narrow fracture gaps, including American Petroleum Institute (API) Class G (A1, largest particles), Portland limestone-blended cement (A2, medium particles), microfine cement (A3, smallest particles), and semi-microfine API Class C (A4). Cylindrical cement plugs were cured at 6890 kPa and 50°C for 7 days and cut into halves to create replicas of fractured cement samples. Metal shims of 150 μm, 100 μm, and 50 μm in thickness were used to control the gap size. Cement microsqueeze jobs were conducted under a differential pressure of 2068 kPa (300 psi) using a conventional core flow setup. The fractured cement samples were imaged using microcomputed tomography (CT) scanning before and after remediation to determine both the fracture width and the slurry flow pathway. Results showed that A2, A3, and A4 cement were able to fully penetrate and seal fractures ≥70–80 μm, whereas A1 experienced bridging and nonuniform penetration. For narrower gaps (around 40 μm), none of the tested cement blends achieved complete penetration. A reduction (varying between three and six orders of magnitude) of the fracture conductivity was observed after squeeze cementing, even though the cement did not fully penetrate the fractured cement samples in some cases. Squeeze cement slurry progression in the fracture takes place in several modes, all controlled mainly by the narrowest gap width size (GW)/particle size (PS) ratio. At a high GW/PS ratio, the cement slurry was distributed uniformly. At a moderate GW/PS ratio, bridging and partial plugging of the fractures were observed, leading to slurry flow in a fingered pattern. At low GW/PS ratio, only filtrate flow was observed. Comparison of the results from all 13 cases of squeeze cementing experiments conducted throughout this study suggests that there may be a critical GW/PS (D90) ratio, which controls the particle bridging vs. flow (and the depth of cement slurry penetration into the fracture), and this number is somewhere between 2.2 and 2.4. When the minimum fracture GW/PS (D90) ratio is around 2.2 or lower, cement slurry starts to bridge, thus preventing further filling of the gap by the squeezed cement. When the minimum fracture GW/PS (D90) ratio is sufficiently higher than 2.2, cement bridging does not occur, and the cement slurry completely fills the fracture. When the minimum fracture GW/PS (D90) ratio is much less than 2, the cement slurry flow stops suddenly in the narrowest region without any fingering and filtration. Preliminary results from this study suggest that remedial cementing penetration strongly correlates with fracture gap size/cement particle size (D90) ratio. However, more data, like those presented in this study, are needed before we can suggest a more accurate value of critical GW/PS ratio, which controls the probability of plugging in any squeeze job.
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".