Experimental and Numerical Investigations of Borehole Ballooning in Rough Fractures
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
Summary Borehole ballooning/breathing is a combined mud-loss/-gain event observed during drilling operations in naturally fractured formations. Factors controlling this phenomenon must be well understood to correctly interpret its symptoms observed during drilling to avoid mixing ballooning with other formation flow incidents that might lead to unwarranted well-control procedures. A mathematical model defining the ballooning process was developed and solved numerically using finite-difference approximation. It was shown that fracture roughness and fracture deformation play a significant role in the flow of drilling fluid in and out of a single fracture. In this study, the focus was mainly on the effect of fracture roughness (characterized by the fractal dimension of the fracture surface) and fracture aperture. The main goal of this work was to compare the numerical-model results with laboratory-scale experimental observations. Therefore, experiments were performed to study the mud-loss and -gain events in artificially fractured rock samples. Cylinders of Berea sandstone, Indiana limestone, and granite were used for the experiments (1-in. diameter, 3-in. length). Two different fracture types were used to analyze the effect of fracture-surface roughness on the flow of drilling fluid in and out of the fracture. To create smooth fracture surfaces, cores were cut precisely into two equal pieces using a blade. Alternatively, axial load was applied on the cylindrical rock samples until a longitudinal fracture with a rough surface was generated. The results of experimental observations and numerical-model study on the importance of fracture roughness were provided. Situations where the degree of roughness becomes critical were identified.
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