Structure & work packages
Throughout this project, the ITHERLAB team will address a fundamental question in temperature and heat-flow studies: How are in-situ rock thermal conductivity and thermal diffusivity affected by the temperature (T) and pressure (p) conditions, and how can the proposed relations be quantified? This question will be decomposed into two individual research objectives:
Objective 1: Development of laboratory in-situ device
The first objective corresponds to a single high-risk but high-reward work package (WP1) developing a special laboratory device to measure rock thermal conductivity and thermal diffusivity under elevated p/T conditions (in-situ). The new device will be able to carry out laboratory measurements under in-situ conditions in unprecedented accuracy under simultaneously elevated p/T conditions typical for the depth of deep boreholes. In contrast to the majority of previously published approaches, variable p/T conditions can be applied simultaneously to fluid-saturated rocks, reflecting the conditions in the geological subsurface.
Objective 2: Mathematical formulation of p/T dependence of rock thermal conductivity and thermal diffusivity
For the second objective three work packages (WP2-WP4) are designed, aiming at exploring the interrelations between rock thermal properties and the p/T conditions during the measurement. Once the device is established, data measured at ambient conditions will be validated by state-of-the art measurements with an optical scanning apparatus (TCS). In a second step, a measurements series at elevated p/T conditions will be carried out with the new device. Additional petrophysical rock properties will be determined using different techniques. Both measurement series will be compared to explore the impact of p/T on the rock thermal properties. These examinations are supported using imaging methods like CT. The uniqueness of this approach is that for the first time a systematic measurement campaign is designed involving a new, reliable measurement device (from objective one) and large sets of different types of crystalline and sedimentary rocks to statistically quantify the above mentioned effects.
Overview of work packages and tasks:
The aim of the work packages is: first adapting and extending the laboratory prototype apparatus to elevated p/T conditions (WP1), then validating the measurement results under ambient conditions with standard TC/TD measurements ( WP2), then use the new apparatus to generate new data on rock thermal properties at elevated (in-situ) p/T conditions on a variety of different rock types (different types of sedimentary, metamorphic and crystalline rocks) (WP3), and then use the new data to derive a mathematical formulations for the impact of p/T on the in-situ TC/TD ( WP4).More information: scientific background | team |