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Title: Modeling and analysis of drag-bit cutting

Abstract

This report documents a finite-element analysis of drag-bit cutting using polycrystalline-diamond compact cutters. To verify the analysis capability, prototypic indention tests were performed on Berea sandstone specimens. Analysis of these tests, using measured material properties, predicted fairly well the experimentally observed fracture patterns and indention loads. The analysis of drag-bit cutting met with mixed success, being able to capture the major features of the cutting process, but not all the details. In particular, the analysis is sensitive to the assumed contact between the cutter and rock. Calculations of drag-bit cutting predict that typical vertical loads on the cutters are capable of forming fractures. Thus, indention-type loading may be one of the main fracture mechanisms during drag-bit cutting, not only the intuitive notion of contact between the front of the cutter and rock. The model also predicts a change in the cutting process from tensile fractures to shear failure when the rock is confined by in-situ stresses. Both of these results have implications for the design and testing of drag-bit cutters.

Authors:
Publication Date:
Research Org.:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
OSTI Identifier:
6006329
Report Number(s):
SAND-83-0278
ON: DE83015634
DOE Contract Number:  
AC04-76DP00789
Resource Type:
Technical Report
Resource Relation:
Other Information: Portions are illegible in microfiche products. Original copy available until stock is exhausted
Country of Publication:
United States
Language:
English
Subject:
15 GEOTHERMAL ENERGY; CUTTING; MATHEMATICAL MODELS; DIAMONDS; DRILL BITS; FAILURES; FINITE ELEMENT METHOD; PLASTICITY; SANDSTONES; TENSILE PROPERTIES; VALIDATION; WELL DRILLING; CARBON; DRILLING; DRILLING EQUIPMENT; ELEMENTAL MINERALS; ELEMENTS; EQUIPMENT; MACHINING; MECHANICAL PROPERTIES; MINERALS; NONMETALS; NUMERICAL SOLUTION; ROCKS; SEDIMENTARY ROCKS; TESTING; Geothermal Legacy; 150901* - Geothermal Engineering- Drilling Technology & Well Hardware

Citation Formats

Swenson, D V. Modeling and analysis of drag-bit cutting. United States: N. p., 1983. Web. doi:10.2172/6006329.
Swenson, D V. Modeling and analysis of drag-bit cutting. United States. https://doi.org/10.2172/6006329
Swenson, D V. 1983. "Modeling and analysis of drag-bit cutting". United States. https://doi.org/10.2172/6006329. https://www.osti.gov/servlets/purl/6006329.
@article{osti_6006329,
title = {Modeling and analysis of drag-bit cutting},
author = {Swenson, D V},
abstractNote = {This report documents a finite-element analysis of drag-bit cutting using polycrystalline-diamond compact cutters. To verify the analysis capability, prototypic indention tests were performed on Berea sandstone specimens. Analysis of these tests, using measured material properties, predicted fairly well the experimentally observed fracture patterns and indention loads. The analysis of drag-bit cutting met with mixed success, being able to capture the major features of the cutting process, but not all the details. In particular, the analysis is sensitive to the assumed contact between the cutter and rock. Calculations of drag-bit cutting predict that typical vertical loads on the cutters are capable of forming fractures. Thus, indention-type loading may be one of the main fracture mechanisms during drag-bit cutting, not only the intuitive notion of contact between the front of the cutter and rock. The model also predicts a change in the cutting process from tensile fractures to shear failure when the rock is confined by in-situ stresses. Both of these results have implications for the design and testing of drag-bit cutters.},
doi = {10.2172/6006329},
url = {https://www.osti.gov/biblio/6006329}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Fri Jul 01 00:00:00 EDT 1983},
month = {Fri Jul 01 00:00:00 EDT 1983}
}