Abstract
ABSTRACT Axial point-load tests involve breaking specimen disks of rock with small, diametrically opposed anvils that approximate point loads. Direction of sample fracture can reflect strength anisotropy, which in otherwise homogeneous samples may correspond to the strike of natural microfractures or microfractures that exist owing to processes that reflect in situ stress directions, such as differential core expansion. In low-permeability sandstone reservoir rocks, point-load tests are potentially useful supplements to core-based studies of macrofractures and measurements of stress directions. Point-load tests on low-permeability sandstone core show marked strength anisotropy in soft Frontier Formation sandstone (Green River Basin, Wyoming) and moderate to weak anisotropy in hard Travis Peak Formation sandstone (East Texas Basin). Comparing results of 328 point-load tests with other stress-direction indicators (acoustic velocity anisotropy, anelastic strain recovery, wellbore breakouts, and hydraulically induced fractures), agreement was found between induced fracture strike and inferred maximum horizontal stress direction. The strike of induced fractures is also aligned with natural fracture directions in these rocks, however, and petrographic analysis is necessary in order to use point-load tests to infer stress directions.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.