Experimental Investigation of the Effect of Shale Anisotropy Orientation on the Main Drilling Parameters Influencing Oriented Drilling Performance in Shale
Bibliographic record
Abstract
The influence of shale anisotropy and orientation on shale drilling performance was studied with an instrumented laboratory drilling rig with a 38.1-mm dual-cutter polycrystalline diamond compact (PDC) bit, operating at a nominally fixed rotational speed with a constant rate of flow of drilling fluid—water. However, the rate of rotation (rpm) was affected by the weight on bit (WOB), as was the torque (TRQ) produced. The WOB also affected the depth of cut (DOC). All these variables, WOB, rpm, TRQ, and DOC, were monitored dynamically, for example, rpm with a resolution of one-third of a revolution (samples at time intervals of 0.07 s.) The shale studied was from Newfoundland and was compared with similar tests on granite, also from a local site. Similar tests were also conducted on the concrete made with fine aggregate, used as “rock-like material” (RLM). The shale samples were embedded (laterally confined) in the concrete while drilled in directions perpendicular, parallel, and at 45 deg orientations to bedding planes. Cores were produced from all three materials in several directions for the determination of oriented physical properties derived from ultrasonic testing and oriented unconfined compressive strength (OUCS). In the case of shale, directions were set relative to the bedding. In this study, both primary (or compression) velocity Vp and shear ultrasonic velocity Vs were found to vary with orientation on the local shale samples cored parallel to bedding planes, while Vp and Vs varied, but only slightly, with orientation in tests on granite and RLM. The OUCS data for shale, published elsewhere, support the OUCS theory of this work. The OUCS is high perpendicular and parallel to shale bedding, and is low oblique to shale bedding. Correlations were found between the test parameters determined from the drilling tests on local shale. As expected, ROP, DOC, and TRQ increase with increasing WOB, while there are inverse relationships between ROP, DOC, and TRQ with rpm on the other hand. All these parameters vary with orientation to the bedding plane.
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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 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| 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".