Measuring Capillary Pressure-Saturation Curves Using Thermomechanical Analysis of Drill Cuttings

Capillary pressure-saturation (Pc-Sw) curves are of paramount significance in reservoir analysis, modeling, and evaluation for several reasons. They provide crucial information about fluid distribution in porous media and can be used to forecast oil recovery, locate oil-water and gas-oil contacts, formulate reservoir simulation models, and calculate fluid relative permeability. However, conventional experimental methods for capillary pressure measurement are beset with several limitations. The centrifuge method, for instance, involves complex analysis that can lead to calculation errors, while the mercury injection method requires the use of hazardous mercury, which is damaging to the core, and is also considered disposable. Furthermore, dynamic methods are often time-consuming and expensive. These methods are limited by their reliance on core samples, which are often in short supply, due to the high cost of coring. In Iran, for instance, only 10% of drilled wells include the coring process, leaving core samples unavailable for almost 90% of the wells. Drill cuttings, however, are readily available for every single well, as they are produced without any extra cost during the drilling process. To the best of our knowledge, there is currently no method for measuring the Pc-Sw curve from drill cutting samples. In this study, we present a novel setup based on thermomechanical theory for investigating capillary pressure using drill cuttings. This experimental method takes 3 to 4 hours per sample and is significantly more cost-effective compared to conventional methods. Additionally, the thermodynamic modeling employed in this method permits the measurement of imbibition and drainage curves in all directions of the rock .sample, providing highly accurate capillary pressure data