Abstract
Within the framework of the article, detailed comparative study of Russian normative documents (GOST) and international standards (ASTM) related to elastic properties and rock strength was done. In the article, strength and weakness analysis of existing methods of core sample testing was done and necessity of their revision was shown. It was demonstrated that rock strength characteristics, such as uniaxial compression strength (UCS) and angle of internal friction (FANG), determined following GOST’s procedures, do not always meet the requirements of geomechanical modelling.
The results gathered within the scope of the study could be used as methodological foundations for triaxial compression tests (TXC). The described technique of core sample testing implies confining pressure values different from those in GOST procedures; this allows specifying the values of UCS, FANG, and elastic constants measured by core sample tests. In addition, an algorithm was developed to determine strength characteristics based on results of reinterpretation of strength failure envelopes, also known as rock strength passport, compiled according to GOST.
The study shows that the proper selection of core sample test parameters such as confining pressures corresponding to reservoir conditions is a critical consideration and is directly linked to obtaining reliable results from geomechanical modelling in the future.
