The Conversion of Spirit of Columbus Semi-submersible into Petrobras 36
Bibliographic record
Abstract
Abstract The conversion of the former Spirit of Columbus semisubmersible into the production unit P-36 for the Phase 1 of Roncador Field faced a set of challenges. The actual platform has the capacity to process 180,000 bopd of oil and to compress 7.2 million m3/d of gas. Allied to the huge process plant capacity, P-36 is installed at 1,360 m of water depth and a total of 90 risers will be connected to the Unit, mainly from 21 subsea production wells and 5 subsea water injection wells. This paper presents the design and fabrication phases of this conversion performed in England, Canada and Brazil over a 31-month period spanning from 1997 to 1999. Unique aspects of the conversion, such as process facility, hull modifications and mooring system design is discussed. Despite of being one of the biggest semi-submersibles in the world, a set of modifications was required to comply with its new function. This paper also addresses the management challenges in order to minimize risks, budget and schedule overruns with the strategy to the project development in parallel with the appraisal well phase. Many interfaces with other activities have been successfully managed through a true integrated team approach. Introduction The Phase 1 of Roncador Field Development comprises 21 subsea production wells producing 180,000 bopd through flexible lines to a production semi-submersible P-36 located at 1,360 m water depth. After the processing and treatment operation the oil is transferred to the dedicated Floating Storage and Offloading unit (FSO) P-47 for storage and later exportation to shore via shuttle tankers (Fig. 1). The compressed gas is exported, through a new 10-inch gas pipeline, connected to a pipeline manifold (PLAEM), and, from there to an existing fixed platform (PNA-1), through a new 20-inch diameter pipeline. On PNA-1, the gas pipeline is connected to the existing gas to shore pipeline network. The P-47 is a former VLCC, converted to an FSO. It is equipped with storage and transfer facilities, including cargo pumps and offloading system. Oil and fuel gas from P-36 flow to the P-47 via a turret system. An electric-optical cable for power supply and data exchange is connected through a special swivel for both functions. Dual fuel - gas and Diesel oil - engines are dedicated to three main generators and cargo pumps. There is a small fuel gas plant fed by P-36. Roncador Field was discovered in October 1996 pointing out as one of PETROBRAS most promising production prospects. And only 5 months later the detail engineering of the semi-submersible had already started. The strategy was a fast track development with parallel investments among appraisal well program, technological development and first phase development bringing a set of challenges that might be surpassed during the project. Paper OTC 12136 (Ref.1) presents an overview of Roncador development program. Contract History In January 1997, the Spirit of Columbus semi-submersible was chartered by PETRO-DEEP, on a bareboat basis, to Braspetro Oil Services Company - BRASOIL to be used at Marlim Sul Field.
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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 | 0.000 |
| 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".