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Title: Geothermal Compax drill bit development. Semiannual technical report, July 1, 1976--December 31, 1976

Abstract

Results obtained from instrumented single-diamond compact cutter experiments, wear and failure mode analysis, and preliminary bit design concepts are described. A model was developed relating rock cutting forces to the independent diamond cutting variables, using a statistical test design and regression analysis. The model was tested with additional independent cutting data and a satisfactory fit obtained. Experiments on two rock types (with compressive strengths of 8 x 10/sup 3/ psi and 21 x 10/sup 3/ psi respectively) were completed and a third has been initiated. Preliminary analysis of single cutter experimental results indicates that optimum rake angles for cutters on an actual bit will be a function of each cutter's engagement (depth of cut). Wear test results on five types of COMPAX/sup R/ diamond compacts continuously cutting sandstone under non-impact conditions are reported. Wear rates for both types were equivalent at high cutting speeds, where thermal effects were thought to be operative. At speeds below approximately 400 sfm, the coarser sintered diamond product was superior. The wear rate of a diamond compact tested on Texas Pink granite was calculated and found to be almost two orders of magnitude greater than the wear rate of the same product as determined bymore » CR and D. The higher wear rate is thought to be the result of cyclic impact loading and thermal effects at the cutter-rock interface. Test results are also discussed for interrupted cuts with high negative back rake angles which generated cracks in diamond compacts. Preliminary bit design concepts were developed, including various options dependent upon compact attachment techniques, bit body materials, and available technology for actual construction. Diamond compact attachment is discussed in the Appendix of this report.« less

Authors:
;
Publication Date:
Research Org.:
General Electric Co., Schenectady, NY (USA)
OSTI Identifier:
6548255
Report Number(s):
TID-28702
DOE Contract Number:  
EX-76-C-01-2360
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
15 GEOTHERMAL ENERGY; DOLOMITE; ROCK DRILLING; DRILL BITS; DESIGN; PERFORMANCE TESTING; GRANITES; MARBLE; SANDSTONES; COMPRESSION STRENGTH; CRACKS; DIAGRAMS; DIAMONDS; GEOTHERMAL WELLS; IMAGES; MATHEMATICAL MODELS; MECHANICAL TESTS; STATISTICS; TABLES; WEAR; WELL DRILLING; ALKALINE EARTH METAL COMPOUNDS; CARBON; CARBON COMPOUNDS; CARBONATE ROCKS; CARBONATES; DATA FORMS; DRILLING; DRILLING EQUIPMENT; ELEMENTS; EQUIPMENT; IGNEOUS ROCKS; MAGNESIUM CARBONATES; MAGNESIUM COMPOUNDS; MATERIALS TESTING; MATHEMATICS; MECHANICAL PROPERTIES; METAMORPHIC ROCKS; MINERALS; NONMETALS; OXYGEN COMPOUNDS; RESERVOIR ROCK; ROCKS; SEDIMENTARY ROCKS; TESTING; WELLS; Geothermal Legacy; 150901* - Geothermal Engineering- Drilling Technology & Well Hardware

Citation Formats

Hibbs, Jr, L E, and Flom, D G. Geothermal Compax drill bit development. Semiannual technical report, July 1, 1976--December 31, 1976. United States: N. p., 1976. Web. doi:10.2172/6548255.
Hibbs, Jr, L E, & Flom, D G. Geothermal Compax drill bit development. Semiannual technical report, July 1, 1976--December 31, 1976. United States. doi:10.2172/6548255.
Hibbs, Jr, L E, and Flom, D G. Fri . "Geothermal Compax drill bit development. Semiannual technical report, July 1, 1976--December 31, 1976". United States. doi:10.2172/6548255. https://www.osti.gov/servlets/purl/6548255.
@article{osti_6548255,
title = {Geothermal Compax drill bit development. Semiannual technical report, July 1, 1976--December 31, 1976},
author = {Hibbs, Jr, L E and Flom, D G},
abstractNote = {Results obtained from instrumented single-diamond compact cutter experiments, wear and failure mode analysis, and preliminary bit design concepts are described. A model was developed relating rock cutting forces to the independent diamond cutting variables, using a statistical test design and regression analysis. The model was tested with additional independent cutting data and a satisfactory fit obtained. Experiments on two rock types (with compressive strengths of 8 x 10/sup 3/ psi and 21 x 10/sup 3/ psi respectively) were completed and a third has been initiated. Preliminary analysis of single cutter experimental results indicates that optimum rake angles for cutters on an actual bit will be a function of each cutter's engagement (depth of cut). Wear test results on five types of COMPAX/sup R/ diamond compacts continuously cutting sandstone under non-impact conditions are reported. Wear rates for both types were equivalent at high cutting speeds, where thermal effects were thought to be operative. At speeds below approximately 400 sfm, the coarser sintered diamond product was superior. The wear rate of a diamond compact tested on Texas Pink granite was calculated and found to be almost two orders of magnitude greater than the wear rate of the same product as determined by CR and D. The higher wear rate is thought to be the result of cyclic impact loading and thermal effects at the cutter-rock interface. Test results are also discussed for interrupted cuts with high negative back rake angles which generated cracks in diamond compacts. Preliminary bit design concepts were developed, including various options dependent upon compact attachment techniques, bit body materials, and available technology for actual construction. Diamond compact attachment is discussed in the Appendix of this report.},
doi = {10.2172/6548255},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1976},
month = {12}
}