Drilling and Excavation Technologies for the Future (1994) / Chapter Skim
Currently Skimming:
5. Rock Excavation Tools
5. Rock Excavation Tools
Pages 63-86
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 63... ...
I "Novel" or "advanced" drilling tools utilize exotic systems such as lasers or electron beams to melt or vaporize rock or explosives, or elec~ohydraulic discharges, to impact and shatter rock.
|
From page 64... ...
Because the cross-sectional area of a tunnel face is 10 to 100 times greater than a typical drilihole, it is very unlikely that thermal spelling, melting, or vaporization drills could be used as the sole rock removal process due to extremely high power requirements and very low penetration rates. Similarly, chemical drills would not be practical for tunneling because of the large volume of highly reactive chemicals required, safety problems, and problems associated with chemical treatment and disposal of contaminated spoils.
|
From page 65... ...
ROCK EXCAVATION TOOLS OXYGEN I h n new WATER BURNER ASSEMBLY DRILLING FLUID LIQUID NITROGEN STEAM ~ DETRITUS .'~,2 II /~": On In...
|
From page 66... ...
CRYSTAL OR GAS REAMER LASER . FIGURE 5.3 Melting and vaporization drills (Maurer, 1970)
|
From page 67... ...
ROCK EXCAVATION TOOLS 67 TABLE 5.1 Specific Energy Requirements for Rock Drilling (Maurer, 1968)
|
From page 68... ...
. ;~ DRILUNG FLUID SECONDARY NOZZLE PELLET 7 DRILUNG FLUID COIL ABRASION AND EMnTER ~ :.~1 :/— CAVITATION ULTRASONIC Because of the high power requirements of novel drilling techniques, advances are more likely to be made on combined novel-mechanical drill bits in which the novel devices (e.g., high-pressure water jets)
|
From page 69... ...
A similar system could be used to speed up Me advance rate of tunnel boring machines (TBMs; Figure 5.7~. Cubing slots In the rock with a novel device weakens the rock and allows conventional cutters to break Me rock into larger fragments (Figure 5.8~.
|
From page 70... ...
70 c War r ~ . ~~~ '~ CRAtERING INDEXING ROCK CONVENTIONAL DnIling and Excavation Technologies for the Future _ r I r \ 5, ~ item fit/ '~ LARGE FRACTURES · ,/1 NOVEL— ROCK BREAKAGE COMBINAllON NOVEL- COVENTIONAL FIGURE 5.8 Combined rock fragmentation (Maurer, 1980~.
|
From page 71... ...
In laboratory tests, the overpowered motor drilled marble blocks at rates up to 550 ft/h, compared to 225 ft/h with normal motor operation. Special high-power bits Mat utilized oversize man-made thermally stable polycrystalline diamond CTSP)
|
From page 72... ...
72 BEARING ~ DRIVE ~~ SHAFT ASSEMBLY/ UPPER THRUST BEARING / Or ,' ~ TWO PIECE RADIAL BEARING .~ LOWER THRUST BEARING \~ BIT CONNECTION BOX Drilling aru] Excavation Technologies for the Future Cutaway view of new PDM motor DUMP VALVE ASSEMBLY WITH TOP CONNECTION BOX MOTORS COUPLING SHAFT ASSEMB~v IFT SUB— ,~ / FIGURE 5.~1 Cutaway view of new positive displacement mud motor (Dempsey and Leonard, 1979~.
|
From page 73... ...
Shear-type bits utilize polycrystalline or natural diamond cutters to remove rock by shearing processes. Polycrystalline diamond cutter ~DC)
|
From page 74... ...
. Advanced TBM Cutters Tunnel boring machines utilize disk or took roller cutters to disintegrate rock (Figure S
|
From page 75... ...
75 c Into> - .£ ~ ~ V V TOOTH Existing TBMs in soft rock are now capable of such high advance rates Mat muck removal, rather than rock cutting, is becoming the limiting process for Me system. Thus, significant improvements in excavation will require parallel development of bow the rock cutting and Me muck removal components of the system.
|
From page 76... ...
. '—__ _ EROS ON UIS Mono - lS - 0 ~ 20 ~ ~ SO 60 70 a07~ ~ _ ~ -__ ~ FIGURE 5.~S Exxon drilling data for high-pressure versus conventional bits (Maurer and others, 1973~.
|
From page 77... ...
. so do ~ 30 10 o S 6 77 U" Jaded 1~1: Com~entio~al Thousands Depth, feet 9 10 FIGURE 5.20 FlowDri} field test data for an east Texas oil field test (Kolle and others, 1991~.
|
From page 78... ...
Guided Percussion Drills Percussion or hammer drills can penetrate many hard rocks two to four times faster Han rotary drills because Hey apply high-impact loads that shatter the rock into large fragments. Although widely used in shallow blast-hole operations, percussion drills have found limited use for deep oil, gas, and geothermal drilling because of the inability to accurately guide
|
From page 79... ...
interactions. Revolutionary advances in rates of rock breaking and rock removal are possible through the development of hybrid mechanical-nove} drilling tools to break and remove rock.
|
From page 80... ...
4. Improved mechanical drills: Significant improvements in rock removal rates can also be obtained through evolutionary advances in conventional mechanical drilling tools.
|
From page 81... ...
V., and Bolotov, A V., 1966, Use of an electric arc for rock boring: ~zvestiia Vysshikh Uchebnykh Zavedenii, Tsvetsnaya Metallurgiya USSR, May.
|
From page 82... ...
R., 1970, Heat-Assisted Tunnel Boring Machines: United Aircraft Research Laboratories, East Hartford, Conn., September (NTIS-PB-197, 243)
|
From page 83... ...
O., 1974, Focused Laser Beams to Assist Rock Excavation: United Aircraft Research Laboratories, East Hartford, Conn., DOT Contract No.
|
From page 84... ...
M., 1975, Status Report Drilling Research on the Electrical Detonation and Subsequent Cavitation in a Liquid Technique (Spark Drilling) : SandiaLaboratories Report No.
|
From page 85... ...
W., and Holdbrook, R G., 1972, Use of Electron Beam Gun for Hard Rock Excavation Final Report: ARPA Contract No.
|
From page 86... ...
Young, F M., 1963, The secondary breaking effect of heat-frequency electric energy applied to rock fragments: in Rock Mechanics, Fairhurst, C., ea., Oxford, Pergamon Press, p.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.