Modeling and analysis of drag-bit cutting

Technical Report · Fri Jul 01 04:00:00 EDT 1983

DOI:https://doi.org/10.2172/6006329· OSTI ID:6006329

Swenson, D V

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.

• Research Organization: Sandia National Labs., Albuquerque, NM (USA)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 6006329
• Report Number(s): SAND-83-0278; ON: DE83015634
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
150901* -- Geothermal Engineering-- Drilling Technology & Well Hardware
CARBON
CUTTING
DIAMONDS
DRILL BITS
DRILLING
DRILLING EQUIPMENT
ELEMENTAL MINERALS
ELEMENTS
EQUIPMENT
FAILURES
FINITE ELEMENT METHOD
Geothermal Legacy
MACHINING
MATHEMATICAL MODELS
MECHANICAL PROPERTIES
MINERALS
NONMETALS
NUMERICAL SOLUTION
PLASTICITY
ROCKS
SANDSTONES
SEDIMENTARY ROCKS
TENSILE PROPERTIES
TESTING
VALIDATION
WELL DRILLING