Thermal core profiling as a novel and accurate method for efficient characterization of oil reservoirs

Integration of Thermal Core Profiling and Scratch Testing for the Study of Unconventional Reservoirs

“…This means that an increase in the silicon content is accompanied by a decrease in the organic matter content and, consequently, by an increase in UCS (as in the siliceous mudrocks from the Wolfcamp/Leonard strata, Midland Basin, Texas [32]). The thermal conductivity decreases with increasing TOC [33], as the thermal conductivity of organic matter is more than ten times lower than the thermal conductivity of the mineral matrix [12].…”

“…Higher-porosity domains in a material are usually weaker and less conductive than low-porosity zones. Therefore, it is not surprising that there are approaches to transform the UCS profile [9] or the thermal conductivity profile [12] into a porosity profile for fixed lithology. However, porosity cannot easily and unambiguously be determined from either core or log data in organic shales [34].…”

“…First, although these properties are influenced by practically the same factors-the mineral composition and organic matter content, porosity, fluid saturation, textural features, etc.-it can affect thermal conductivity and UCS in many ways. For example, the UCS of a dry sample will exceed that of a sample when saturated [1,35], while the thermal conductivity of a dry sample will be below that when saturated by oil, water, or its mixture (thermal conductivity is about 0.58-0.6 W•m −1 •K −1 for water, 0.10-0.18 W•m −1 •K −1 for oil/kerosene, 1.3-7.6 W•m −1 •K −1 for mineral matrix [12]). Waterwet samples are often weaker than kerosene-wet samples [33], while the thermal conductivity of water-wet samples is higher than that of kerosene-wet samples (kerosene is used as a thermal oil model in experiments because of its similarity in thermal properties).…”

“…Heterogeneity is defined by the spatial variability in rock texture and composition and can be quantified and tracked at different scales (core, logging, or seismic). Fine-scale heterogeneity over the core column length can be described via CT scanning [1,5], scratch testing [4,[6][7][8][9], and thermal core profiling [10][11][12]. CT scanning provides a quantitative evaluation of the X-ray attenuation number (related to the density and atomic number).…”

“…It is partially destructive and, as a result, rarely carried out in practice for samples/rock types extremely sensitive for mechanical treatment. Continuous high-resolution (0.2-2 mm) thermal profiling along a core sample column provides measurements of the fundamental (thermal) physical properties of rocks, accounting for anisotropy in a non-contact, non-destructive manner right at the core storages [11,12].…”