Gravel-Pack Evaluation Using a Memory Gamma-Gamma Density Tool
Bibliographic record
Abstract
Gravel-Pack Evaluation Using a Memory Gamma-Gamma Density Tool Kevin Fisher; Kevin Fisher ProTechnics Search for other works by this author on: This Site Google Scholar Calvin Kessler; Calvin Kessler Halliburton Energy Services Search for other works by this author on: This Site Google Scholar Fritz Rambow; Fritz Rambow Shell EP Technology Applications and Research Search for other works by this author on: This Site Google Scholar Charles Tucker; Charles Tucker Shell Exploration and Production Company Search for other works by this author on: This Site Google Scholar William Madigan William Madigan Multiphysics Numerical Research Group Search for other works by this author on: This Site Google Scholar Paper presented at the SPE International Symposium on Formation Damage Control, Lafayette, Louisiana, February 2000. Paper Number: SPE-58779-MS https://doi.org/10.2118/58779-MS Published: February 23 2000 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Fisher, Kevin, Kessler, Calvin, Rambow, Fritz, Tucker, Charles, and William Madigan. "Gravel-Pack Evaluation Using a Memory Gamma-Gamma Density Tool." Paper presented at the SPE International Symposium on Formation Damage Control, Lafayette, Louisiana, February 2000. doi: https://doi.org/10.2118/58779-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search Dropdown Menu nav search search input Search input auto suggest search filter All ContentAll ProceedingsSociety of Petroleum Engineers (SPE)SPE International Conference and Exhibition on Formation Damage Control Search Advanced Search AbstractCompletions in poorly consolidated formations often require gravel packing or frac packing to eliminate the inflow of formation fines. The effectiveness of gravel placement in the screen-casing annulus or open hole annulus or behind casing (such as when prepacking perforation tunnels) may be qualitatively evaluated with treatment-pressure data. Voids in the gravel-packed screen-casing or open hole annulus are evaluated with data from density, neutron, gamma-tracer, or pulsed-neutron logs. When radioactive materials are used for evaluating proppant placement in the formation, however, gamma measurements are affected by the background signal produced by these materials. This signal makes conventional density and pulsed-neutron silicon-activation techniques ineffective.A high-resolution, memory gamma-gamma density logging tool has been developed that measures changes in the bulk density of the annular region of a gravel-pack completion. The source-to-detector spacing and source strength have been optimized to minimize the effects of variations in borehole fluid and of changes in casing-screen size and geometry. Most importantly, this measurement will not be affected by the presence of radioactive tracers used to evaluate proppant placement.The new memory-based logging system allows the tool to be placed in the wash pipe prior to the completion and for the logging pass to be recorded as the wash pipe is retrieved from the well. Significant savings in rig costs and in time to production are gained through use of the wash pipe-conveyed memory logging technique. This paper reviews the measurement principles of the tool and presents data from tests in calibration pits.BackgroundIn 1996, Shell began tracing frac pack completions on several deepwater projects in the Gulf of Mexico. Due to the significant costs of rig time for wire line spectral gamma logging, Pro Technics was asked to develop a wash pipe conveyed spectral logging tool. Since that time, numerous completions have been traced and logged in that manner. On several of these completions, intervals with lower annular tracer counts were seen which were interpreted as gaps or voids in the gravel pack (Figs. 1 - 2). Because of the tracer background counts, neutron logs were run in these liquid-hydrocarbon reservoirs as a follow-up to verify the voids observed on the tracer surveys. In one of these cases, the screen ultimately failed and in another, the gravel pack was pulled and re-worked. Due to the inherent weaknesses in using neutron measurements, Shell asked Halliburton and Pro Technics to begin developing a gamma-gamma density logging tool which would be insensitive to the tracer background. The original nuclear modeling and tool design was performed by Halliburton and then licensed to Pro Technics for commercialization using existing wash pipe logging technology. The result is a memory gamma-gamma density gravel pack evaluation tool that can be run on wash pipe, wire line, slick line or coiled tubing and which can be run in the presence of radioactive tracers. Results from nuclear modeling and test pit data acquisition from this new tool will be discussed in this paper. Keywords: evaluation, charles tucker, kevin fisher, calvin kessler, log analysis, upstream oil & gas, sand control, density tool, tracer, fritz rambow Subjects: Formation Evaluation & Management, Open hole/cased hole log analysis, Sand Control This content is only available via PDF. 2000. 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 | 0.001 | 0.004 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.023 | 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".