An experimental study to investigate the physical and dynamic elastic properties of Eagle Ford shale rock samples

Abstract Unconventional resources, such as Eagle Ford formation, are commonly classified for their ultra-low permeability, where pore sizes in nano-scale and pore-conductivity is low, causing several challenges evaluating unconventional-rock properties. Several experimental parameters (e.g., diffusion time of gas, gas injection pressure, method permeability measurement, confining pressure cycling) must be considered when the rock's physical dynamic elastic properties measurements, erroneous evaluations could avoided. Characterizing samples' helps researchers obtain more reliable information leading to successful evaluations. In this study, 24 core were evaluated. Utilizing longer higher helium applying complex transient method, cycling porosity, velocities measurements. Computerized tomography (CT) scan, ultrasonic wave conducted on samples. Additionally, X-ray Diffraction (XRD) analysis was determine mineralogical compositions. Porosity measured at 2.07 MPa h, using a method. P- S-wave two cycles five pressures (up 68.95 MPa). The XRD results showed that tested samples had an average 81.44% 11.68% calcite quartz, respectively, with minor amount clay minerals. high content quartz shale yields velocities, Young's modulus, lower Poisson's ratio, which enhances brittleness important parameter well stimulation design hydraulic fracturing). porosity vary between 5.3–9.79% 0.006–12 µD, respectively. Permeability–porosity relation shows very weak correlation. display range velocity up 6206 m/s 3285 approximately 55% P-wave velocity. A correlation both established each indicating strong Results illustrated impacts moduli. Ramping increases owing compaction and, turn, modulus ratio while decreasing bulk compressibility. Moreover, demonstrated above-mentioned parameters' values (after 13.79 MPa) differ from initial due hysteresis loop, loop slightly opened, alteration non-elastic. findings study provide detailed about rock one largest unconventional resources U.S.A, direct measurements may not cost-effective or feasible.