Drilling of an Ultra-Deep Exploratory Well - Problems and Solutions: A Case Study
Bibliographic record
Abstract
Abstract This paper presents a case history on drilling of an ultra-deep exploratory well with a lot of problems and final solution in a complicated K structure in Uzbekistan. Drilling troubles include serious stuckpipe resulted from drilling-in the unexpected high pressure brine formation, malfunction of the high density drilling fluid system, and subsequent failure of the fishing jobs, unsuccessful sidetracking, bad job of cementing, etc. After the drilling fluid system was improved, the high pressure layers were isolated, and the proper drilling measures were carried out, the second sidetracking gained success and the well was completed. Afterwards, an adjacent ultra-deep well in the same structure was smoothly drilled and completed by means of optimization of the casing programs, drilling fluid system and technical measures. Drilling practices of previous offset well indicated that the formation is pay zone and produced oil, while the same formation at the same depth in the well JD3# produces brine water, which resulted in overflow during twice sidetracking of the same formation. The high and low pressure layers existed in the same section after drilling-in brine formation would produce complex against drilling and subsequent operations, therefore a 7-inch liner was set to isolate the high pressure formation, so as to create a good condition for deeper drilling operation. High-density drilling fluid with good precipitation stability and lubricant anti-sloughing properties also contributed to the success in drilling of high pressure brine layer and salt gypsum formation. Accurate determination of the must-be-blocked point is the key to the success. Drilling of the well with problems and its final solution could be used for a technical reference as drilling in deep or ultra-deep wells in similar geologically complicated oil and gas fields.
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 | 0.001 | 0.003 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.003 | 0.002 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.004 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
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".