Stress-Strain and Failure Properties of a Porous Shale (1973)

Stress-Strain and Failure Properties of a Porous Shale Sidney J. Green; Sidney J. Green Terra Tek, Inc. Search for other works by this author on: This Site Google Scholar Robert M. Griffin; Robert M. Griffin Terra Tek, Inc. Search for other works by this author on: This Site Google Scholar Howard R. Pratt Howard R. Pratt Terra Tek, Inc. Search for other works by this author on: This Site Google Scholar Paper presented at the SPE Drilling and Rock Mechanics Conference, Austin, Texas, January 1973. Paper Number: SPE-4242-MS https://doi.org/10.2118/4242-MS Published: January 22 1973 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Green, Sidney J., Griffin, Robert M., and Howard R. Pratt. "Stress-Strain and Failure Properties of a Porous Shale." Paper presented at the SPE Drilling and Rock Mechanics Conference, Austin, Texas, January 1973. doi: https://doi.org/10.2118/4242-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll ProceedingsSociety of Petroleum Engineers (SPE)SPE Drilling and Rock Mechanics Conference Search Advanced Search AbstractUnconfined and triaxial stress tests were conducted on dry and saturated shale from El Paso's Wagon Wheel No. 1 well. The material tested is in general a very competent shale containing stringers of silt and sand, producing local inhomogeneities which effect unconfined fracture, but do not significantly effect the behavior at higher mean normal pressures. Strong sensitivity of deviatoric maximum stress to mean pressure is observed for dry material, while little increase in deviatoric strength with pressure occurs for the fully saturated material. Dilation accompanies distortional deformation; however, softening or ease of compaction occurs at small distortional strains, before substantial dilation begins. In detail, the deviatoric stiffness (apparent shear modulus) and the pressure-volume relation (compressibility) are stress state and stress path dependent, while the deviatoric strength path dependent, while the deviatoric strength is only stress state dependent.IntroductionMechanical properties of a shale material were obtained for El Paso Natural Gas Company to be used in shock calculations to determine rock breakage, and hence increased permeability, caused by nuclear explosion. The samples tested were taken from a core at the 10,215–10,216 foot depth in El Paso's Wagon Wheel No. 1 well, NW/4 Section 5, Township 30N, Range 108W, Sublette County, Wyoming. Small samples were dry cored from the large core provided by El Paso and tested unconfined and provided by El Paso and tested unconfined and confined to pressures of 6 kbars. Both dry and fully saturated samples were tested, parallel and perpendicular to the large core parallel and perpendicular to the large core axis. Petrofabric analysis was made and photomicrographic observations taken to photomicrographic observations taken to predict and better understand the mechanism predict and better understand the mechanism of fracture.Similar tests were previously conducted for El Paso on a large core of sandstone from 10180.4–10181.0 foot depth. These results are reported in Terra Tek report "Testing Program Conducted for El Paso Natural Gas Company" August, 1970.EXPERIMENTAL TECHNIQUETest techniques are similar, and were described in detail in the previous El Paso report, and in other reports, and will therefore only briefly be covered here. Keywords: Upstream Oil & Gas, kbar, dilation, normal pressure, strength, El Paso, specimen, loading, Swanson, fracture Subjects: Reservoir Characterization This content is only available via PDF. 1973. Society of Petroleum Engineers You can access this article if you purchase or spend a download.