Oil Shale Creep Testing at Elevated Temperatures

摘要

An investigation was made to determine the creep behavior of oil shale at elevated temperatures. During the first phase of the investigation, work done on creep behavior of geologic materials was reviewed and triaxial creep tests on oil shale were planned. Tests at temperatures up to 250 degrees C and axial stress up to 3,000 psi were conducted at no confinement and at confining pressures equal to one-third and two-thirds of axial stress. Wide variations in the elastic properties as well as creep characteristics are exhibited. Creep deformation is more pronounced at elevated temperature but no definite quantitative remarks can be made regarding effect of grade of oil shale due to wide scatter and limited number of data points. Primary creep can be described by a power law. Secondary creep seems to be an experimental function of deviatoric stress. Teritary creep was not observed within the test period.