Experimental investigation on the influence of temperature on the mechanical properties of reservoir rocks

Abstract

Abstract This paper reports an investigation on mechanical properties of reservoir rocks obtained in laboratory at room temperature, and their pertinence to characterize the actual rock behavior under normal downhole or steam injection conditions. The investigation was based on triaxial tests performed by a servo-controlled system on samples of friable sandstones cored from a reservoir in the Potiguar Basin, Northeastern Brazil. The samples were tested at 24°C, 80°C and 150 °C, with confining pressure varying from 2.5 MPa to 20MPa. A finite element elastic-plastic analysis of wellbore stability was performed using mechanical properties obtained at these temperatures, showing quite different yielding zones. Although the results obtained so far are not sufficient to characterize completely these effects, they indicate that a more appropriate range of temperature must be used in laboratory to better represent real downhole and steam injection conditions.