With the beautiful backdrop of a snowy day from the PETRONAS Canada offices in Calgary, Alberta, the NSERC/Energi Simulation Chair in Fundamental Rock Physics and Rock Mechanics was invited to PETRONAS Canada. The invitation comes as a mini workshop at PETRONAS Canada to expand their geomechanics horizon and highlight the outcome of the collaborative work being carried. The mini workshop emphasized the importance of the basics of rock mechanics and how they are crucial in understanding the value of the reservoir. From a geophysical aspect, an automatic scheme for microseismic data processing and source characterization, in particular, utilizing 3D background models for more precise source location and mechanism inversions was also presented. During the mini workshop, Prof. Giovanni Grasselli stressed on the importance of this collaborative work, discussing ways to better leverage the current testing program, thus expanding the scope of the research.
An extended summary of the talks at the mini workshop is presented as follows:
| Rock Mechanics 101 – Giovanni Grasselli |
Rock mechanics is mostly concerned with rock masses on the scale that appears in engineering. It is the theoretical and applied science of the physical behaviour of rock and is the branch of mechanics concerned with the response of rock to the force fields of its physical environment. Over the course of the hour-long talk, the concept of stress and strain acting on rock will be portrayed. Microscopic defects and heterogeneities, as well as their impact on the overall behaviour of the rock will be discussed. Effects of roughness and shear on the behaviour of rock masses will also be briefly introduced. |
| Rock Mechanics Testing – Aly Abdelaziz |
Here we explore the value and the rationale behind conducting rock mechanical testing. The talk will extend to cover conventional rock mechanical testing which include uniaxial compressive strength (UCS), triaxial testing, Brazilian disk (indirect tensile) tests. The value of these tests, along with the interpretation and parameters obtained are introduced. More unconventional tests are then covered which include the proppant embedment test, cracked chevron notch Brazilian disk (CCNBD) tests, and true-triaxial (polyaxial) hydraulic fracturing tests; the latter test is a novel test on Montney shale. The value of advanced testing will be demonstrated, with emphasis on what we have learned from those results. |
| What Next? – Giovanni Grasselli |
| Building on what we learned during the sponsored research project, a proposal was submitted to the Canadian government, through the Natural Science and Engineering Council (NSERC) – Collaborative Research and Development (CRD), to leverage the testing program and expand the scope of the research. Focusing on combining fundamental rock mechanics principles with geophysics imaging, this research project will advance the understanding of the role of pre-existing, incipient, and hydraulically-induced fractures and geological heterogeneities on the reservoir response under changing conditions associated with the various stages of development, from well completion, to stimulation, and then to production. |
| Comprehensive microseismic source characterization: event detection, location and source mechanisms – Qinya Liu |
| We present an automatic scheme developed for processing microseismic data for microseismic source characterizations, including event detection based on convolution neural networks (CNN), event location based on reverse-time ray-tracing, and event location/mechanism inversion for 3D background models based on strain Greens function storage. We also give an update on the moment-tensor inversion on the 2015/08/07 induced earthquake in Northeastern BC. |