Mechanical properties of Devonian shales from the Appalachian Basin

Technical Report · Wed Sep 30 04:00:00 EDT 1981

OSTI ID:6570704

Blanton, T L; Dischler,; Patti, N C

A prime objective of the current study has been to establish wherever possible regional or stratigraphic trends in the various properties required by stimulation research. Lithologically Devonian shales tend to fall into two categories: gray shales and organic-rich black shales. Two black/gray pairs, Huron/Hanover and Marcellus/Mahantango, were selected from four localities in Pennsylvania and Ohio for comprehensive testing. Over 130 experiments were run on these zones to determine elasticity, fracture properties, yield and ultimate strength, and ductility. The results of these tests and previous tests run on core from West Virginia and Kentucky provide a basis for the following conclusions about Devonian shale mechanical properties and their applications in stimulation research: elasticity of Devonian shale matrix material showed no strong trends with respect to either lithology, locality, or confining pressure. Gray shales tended to have a slightly higher Young's modulus than black shales, but the difference between the averages was less than the standard deviation of each average. Ultimate strength, yield strength, and ductility all increase with increasing confining pressure, which is typical for most rocks. Ultimate strength and yield strength tend to be higher for gray shales, whereas black shales tend to be more ductile. Tensile strength showed no particular trends either regionally or lithologically, whereas fracture energy seemed to have the most consistent trends of any material property measured. Black shales tended to have a higher fracture energy, and fracture energy for both black and gray shales tended to increase with depth of burial. Two promising topics for continued study are the effect of confining pressure on fracture energy and the effect of deformation rate on material properties. 16 figures, 9 tables.

• Research Organization: Science Applications, Inc., Steamboat Springs, CO (USA)
• DOE Contract Number: AM21-78MC08216
• OSTI ID: 6570704
• Report Number(s): DOE/MC/08216-1332; ON: DE83006477
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
030900 -- Natural Gas-- Artificial Stimulation
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04 OIL SHALES AND TAR SANDS
040500 -- Oil Shales & Tar Sands-- Properties & Composition
BITUMINOUS MATERIALS
BLACK SHALES
CARBONACEOUS MATERIALS
CHATTANOOGA FORMATION
DATA
DEVONIAN PERIOD
DRILL CORES
DUCTILITY
ELASTICITY
ENERGY SOURCES
EXPERIMENTAL DATA
FEDERAL REGION III
FEDERAL REGION IV
FEDERAL REGION V
FOSSIL FUELS
FRACTURE PROPERTIES
FUELS
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC FORMATIONS
INFORMATION
KENTUCKY
MATERIALS
MECHANICAL PROPERTIES
MINERAL RESOURCES
NATURAL GAS DEPOSITS
NORTH AMERICA
NUMERICAL DATA
OHIO
OIL SHALES
PALEOZOIC ERA
PENNSYLVANIA
RESOURCES
TENSILE PROPERTIES
ULTIMATE STRENGTH
USA
WEST VIRGINIA
YIELD STRENGTH