Feasibility of Fluid-Jet Based Drilling Methods for Drilling Through Unstable Formations
Bibliographic record
Abstract
Feasibility of Fluid-Jet Based Drilling Methods for Drilling Through Unstable Formations A. Gupta; A. Gupta University of Missouri-Rolla Search for other works by this author on: This Site Google Scholar D.A. Summers; D.A. Summers University of Missouri-Rolla Search for other works by this author on: This Site Google Scholar S.V. Chacko S.V. Chacko University of Missouri-Rolla Search for other works by this author on: This Site Google Scholar Paper presented at the SPE International Thermal Operations and Heavy Oil Symposium and International Horizontal Well Technology Conference, Calgary, Alberta, Canada, November 2002. Paper Number: SPE-78951-MS https://doi.org/10.2118/78951-MS Published: November 04 2002 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Get Permissions Search Site Citation Gupta, A., Summers, D.A., and S.V. Chacko. "Feasibility of Fluid-Jet Based Drilling Methods for Drilling Through Unstable Formations." Paper presented at the SPE International Thermal Operations and Heavy Oil Symposium and International Horizontal Well Technology Conference, Calgary, Alberta, Canada, November 2002. doi: https://doi.org/10.2118/78951-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search nav search search input Search input auto suggest search filter All ContentAll ProceedingsSociety of Petroleum Engineers (SPE)SPE International Thermal Operations and Heavy Oil Symposium Search Advanced Search AbstractThis paper presents the development of fluid-jet methods for the drilling of wells through unstable formations. The work demonstrates the technical capabilities of drilling through unstable formations including Methane hydrate and permafrost.Abrasive fluid-jet systems are capable of drilling through rocks of all types, and with greater directional control that is not susceptible to the geologically induced deviations encountered with mechanical bits, since no mechanical contact is made with the rock while drilling. Abrasive fluid-jets drill rock through the erosion induced by very small particles which individually remove only small fragments but are in such numbers that the drilling rate is at or above that of conventional tools. The particles are powered by the velocity of the supporting fluid, generated in turn by pumps on the surface. The cutting occurs ahead of the nozzle body allowing a casing to be used which is of a larger diameter than the drilling assembly itself. Abrasive jets drill through the erosion of the rock under the specific impact point of the jet contact. They do not therefore exert significant force to the rock around the drilling point and erode the rock without inducing great disturbance to the surrounding material, thus enhancing borehole stability. Fluid-jet methods have the potential of improving drilling efficiency through unstable formations.Background and IntroductionDrilling through unstable formations such as shales, friable or unconsolidated sands, shallow glacial drift formations, gas hydrates and perma-frost, is a challenge faced for a long time by the drilling industry. The primary problem in drilling through weak and unstable formations is that the drilled borehole may collapse as soon as the support provided by the drilling assembly is withdrawn. The drilling industry has historically dealt with this problem by:using drilling fluids that exert balancing hydrostatic pressure across the borehole wall and form a stabilizing filter-cake on the walls of the hole;Placing multiple strings of steel casing through the well and injecting a cement slurry between the bore-hole and casing. However, the use of weighted drilling fluids to stabilize borehole is not an option for underbalanced drilling operations.Placing multiple casing strings may be cost-prohibitive, especially for a marginal project. Further, the portion of the wellbore drilled through water-sensitive, fractured or otherwise unstable formations may still collapse during or after drilling when the drill string is withdrawn to run and cement casing. Frequently, such bore hole instability leads to loss of equipment and failure in drilling and completing a well to the desired depth."Casing-drilling" solutions have recently been offered for the oil/gas well drilling. In the "casing-drilling" methods, a wire-line retrievable mechanical drilling assembly is attached to the steel casing. Following the drilling operations, the casing is cemented in place by injecting cement slurry in the annular space between the casing and the borehole. Limitations of prevalent casing drilling methods are:Casing joints may fail during drilling operations due to twist-off, leading to expensive recovery operations;The mechanical rotary drilling process disturbs weak formations to the extent that they cave around the casing causing a stuck casing string.It is believed that fluid-jet drilling methods can help overcome these limitations of casing drilling technology.Since the 1940s rotary drilling has dominated and has been an industry standard in the quest to reach oil and gas formations. However, its limitations start becoming obvious under special applications such as:Drilling of unstable formations;Underbalanced drilling;Coiled tubing drilling;Drilling in remote locations;Drilling in environmentally sensitive locations.Recent advances in abrasive fluid-jet drilling suggest that it may be ideal under conditions listed above for which the conventional rotary drilling systems are severely limited. Keywords: petroleum society, university, assembly, drilling system, limitation, co 2, drilling assembly, nozzle, drilling operation, unstable formation Subjects: Drilling Operations This content is only available via PDF. 2002. SPE/PS-CIM/CHOA International Thermal Operations and Heavy Oil Symposium and International Horizontal Well Technology Conference 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 | 0.002 | 0.005 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.002 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 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".