Abstract
Joint interpretation of seismic and electrical survey data can help to characterize the subsurface better. However, the key to successful joint interpretation is to understand the correlations between elastic and electrical properties (i.e., the joint elastic-electrical properties) of underground rocks. This work aims to investigate the effects of temperature on the joint elastic-electrical properties of porous rocks by simultaneously measuring the P-wave velocity, electrical conductivity, and porosity of five brine-saturated Berea sandstones as a function of varying the temperature from 25°C to 140°C. We find that velocity first increases and then decreases with increasing electrical conductivity alongside an implicitly increasing temperature. We further find that the variation of the temperature-dependent joint elastic-electrical properties is determined by the velocity’s dependence on temperature with a local maximum because electrical conductivity indicates a strong linear increase with increasing temperature. Analyses of the experimental results illustrate that the observed variation of velocity with temperature is a combined and competitive result of the temperature-induced variations in the pore aspect ratio that quantitatively characterizes the pore structure, the properties of the brine that fully saturates the samples, and the porosity of the samples, listed by descending order of importance. The results reveal how the elastic velocity in Berea sandstones is affected by temperature, which, in turn, provides insights into the effects of temperature on the joint elastic-electrical properties of Berea sandstones. This understanding will help improve the joint interpretation of seismic and electrical survey data to characterize petroleum and geothermal reservoirs better.
Paper Information:
Tongcheng Han, Zixuan Du, Haiming He, Li-Yun Fu, 2025. Temperature effects on the joint elastic-electrical properties of Berea sandstones. Geophysics. https://doi.org/10.1190/geo2024-0757.1.
