Calculation of rock compressibility by using the characteristics of downstream pressure change in permeability experiment

• We proposed a new method to evaluate rock compressibility.
• The method is a useful tool when no direct measurement is available.
• Comparing with direct measurement shows that the method is reliable.

In petroleum exploration and production, knowledge of geomechanical properties of target reservoirs ensures producing hydrocarbon safely and economically, and protecting environmental friendly. Rock compressibility, one of the geomechanical properties, is an essential parameter in drilling and completion design. Because direct measurements of rock compressibility are time consuming and cost expensive, indirect measurements from other readily available experimental data are highly demanded. When direct measurements are unavailable or experimental data are unreliable due to lab and human errors, irregular core plug, and/or non-uniform deformation, obtaining rock compressibility from other methods is not only a good reference for the directly measured rock compressibility but also an important supplement to those indirect methods. In this study, a method with solid theoretical base is developed to determine rock compressibility using permeability experimental data. With that, core analysis can be more reliable and accurate. The combination of the proposed method with direct measurements can be employed to ensure the reliability of the experiment and to quantify the uncertainty resulting from lab and human errors.