Microseismic Response of Well Casing Failures at a Thermal Heavy Oil Operation
Bibliographic record
Abstract
Microseismic Response of Well Casing Failures at a Thermal Heavy Oil Operation R.J. Smith; R.J. Smith Imperial Oil Resources Search for other works by this author on: This Site Google Scholar N.S. Alinsangan; N.S. Alinsangan Imperial Oil Resources Search for other works by this author on: This Site Google Scholar S. Talebi S. Talebi CANMET Search for other works by this author on: This Site Google Scholar Paper presented at the SPE/ISRM Rock Mechanics Conference, Irving, Texas, October 2002. Paper Number: SPE-78203-MS https://doi.org/10.2118/78203-MS Published: October 20 2002 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Smith, R.J., Alinsangan, N.S., and S. Talebi. "Microseismic Response of Well Casing Failures at a Thermal Heavy Oil Operation." Paper presented at the SPE/ISRM Rock Mechanics Conference, Irving, Texas, October 2002. doi: https://doi.org/10.2118/78203-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll ProceedingsSociety of Petroleum Engineers (SPE)SPE/ISRM Rock Mechanics Conference Search Advanced Search AbstractImperial Oil's heavy oil operation in northern Alberta utilizes Cyclic Steam Stimulation (CSS) to extract bitumen from the oilsand reservoir (~400 mKB). The operation currently produces over 120,000 bpd from approximately 3000 deviated wells.During CSS, the well casings are subjected to thermal stresses due to the cyclic, high-pressure, high-temperature nature of the process. In addition, shear stresses develop in the overburden due to volumetric dilation of the reservoir during steam injection. The combination of thermal fatigue and shear deformations can occasionally result in casing failures at some location along the wellbore, but typically at the top of the oilsand reservoir.Imperial Oil and CANMET developed the application of passive seismic systems to monitor a volume of the overburden shale for casing failures, as well as for other events. As a result of this monitoring, a model for the seismic signature of well casing failures was developed. The seismic energy and radiation pattern of casing failure events has enabled the passive seismic systems to detect the occurrence of casing failures at the reservoir top, beyond the intended monitoring zone in the overburden shale. Subsequent casing checks have identified that the model detection is correct 88% of the time. In addition, event source location accuracy can be established based on the location of the actual casing failures determined from well workovers. This tool has allowed Imperial Oil to decrease well downtime and develop steaming strategies to reduce the occurrence of casing failures at the top of the reservoir.IntroductionImperial Oil uses Cyclic Steam Stimulation (CSS) at its heavy oil operation in Cold Lake, Alberta. In the CSS process, the same wells are used for high-pressure steam injection, (typically 10–12 MPa), and for production. A typical stratigraphic section for Cold Lake is shown in Figure 1. Steam injected into the Clearwater Sand (CW) is accommodated by hydraulic fractures and non-linear dilation, which result in deformation of the CW1,2. Numerical modeling has demonstrated that shear stresses, which develop at the boundary between the CW sand and the overlying shale, occasionally exceed the expected shear strength of the boundary3. In addition, thermal stresses on the casing impact its ability to withstand shear loads4. These factors are manifested in the field as casing deformations and failures located at or near the top of the CW. Keywords: reservoir characterization, geophone, failure event, velocity model, microseismic response, spe isrm 78203, accuracy, frequency, cw top failure, seismic event Subjects: Reservoir Characterization, Seismic processing and interpretation This content is only available via PDF. 2002. Society of Petroleum Engineers You can access this article if you purchase or spend a download.
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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 | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.007 | 0.002 |
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".