Simulating the Response of Untrenched Flowlines due to Iceberg-Flowline-Soil Interaction
Bibliographic record
Abstract
As offshore oil and gas fields mature on the Grand Banks, offshore Newfoundland and Labrador, marginal field subsea tie-backs are necessary to maintain production levels. Existing untrenched flowline lengths have been limited by the assumption that iceberg contact equates to flowline failure. However, extended tie-backs will be necessary to develop stranded resources. To potentially reduce the number of failure cases, we can consider a better definition of failure that accounts for the pipeline response due to iceberg-soil-pipeline interaction events. Reducing the failure rate from free-floating iceberg contacts alone can significantly increase safe tie-back lengths. This paper examines the flowline response from impacts with free-floating icebergs using large deformation finite element analysis. The plane strain pipe-soil interaction response is first simulated for pure vertical loading and compared against analytical bearing capacity theory. The influence of non-associativity in the soil constitutive model is demonstrated with respect to predicting the pipe drained penetration resistance in dense sands. Oblique vertical-horizontal plane strain pipe-soil interaction is also investigated, and it is shown that the vertical penetration resistance is reduced when the pipe trajectory deviates from pure vertical, consistent with published interaction diagrams. Lastly, the fully coupled interaction scenario of free-floating iceberg-pipe-soil interaction is simulated, showing the effects of the pipe wall thickness and soil strength. The numerical modelling procedures are described and the soil constitutive model that incorporates dense sand behavior is detailed.
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 machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| 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 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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 source (direct Gemma or distilled Codex), 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".