The paper presents the results of a comparative analysis of strength envelopes plotted by two methods — in accordance with GOST 21153.8 and by the multi-stage loading method (ISRM [1]). The importance of this study is associated with a number of issues that arise during selection of core samples for analyzing elastic deformation, as well as during laboratory rock mechanics tests. The comparative analysis of the results shows that a curve that describes an elastic zone of rocks (the so called "strength envelope") can be generated promptly and with greater accuracy if samples are tested by the multi-stage loading method. This method can be recommended for situations where there is no sufficient number of conforming samples for laboratory deformation tests. The paper illustrates correlations for various parameters of the strength envelope plotted by the multi-stage loading method and demonstrates a wellbore stability log based on these correlations.

Keywords:
Reservoir Characterization, gost 21153, Mohr, strength envelope, Upstream Oil & Gas, sample collection, elastic region, rock sample, core analysis, geomechanical model
Subjects:
Reservoir Characterization, Formation Evaluation & Management, Reservoir geomechanics, Core analysis
Copyright 2017, Society of Petroleum Engineers
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