Strain modeling in a marly chalk reservoir

Traditionally, the interpretation of rock-mechanical test results and geomechanical reservoir performance focus on describing stress. Rock strength is typically defined as the peak stress attained before failure. Nevertheless, while rock strength in chalk is strongly dependent on properties such as porosity, cementation and saturating fluid, failure strains are remarkably similar for different specimens and saturating fluids when testing under oedometer conditions (Figure 1A). We propose a method to derive the elastic strain of a formation using petrophysical logging data. We can assess how susceptible to pore collapse each interval is by comparing present levels of elastic strain along a borehole against geomechanical testing data.