Stress sensitivity of sandstones

摘要: Our observations made on dry‐sandstone ultrasonic velocity data relate to the variation in (or modulus) with effective stress, and ability predict a for rock under one pressure when it is known only different pressure. We find that sensitivity of elastic moduli, velocities, hydrostatic stress increases decreasing porosity. Specifically, we calculate difference between an modulus, M(P1,ϕ), sample porosity ϕ at P1 same M(P2,ϕ), P2. If this difference, ΔM=M(P1,ϕ)-M(P2,ϕ), plotted versus suite samples, then scatter ΔM close zero as approaches critical value, reaches its maximum zero. The dependence linear. Critical here above which can exist suspension—between 36% 40% sandstones. This ...