Physical Properties of Carbonate Rock Cuttings vs. Borehole Data: Insights from Ongoing Research

Over the past few years, several scientific projects at Bochum University of Applied Sciences have developed new methods and procedures for determining the petrophysical properties of small rock samples. These workflows, which are part of Digital Rock Physics (DRP) and have been published in peer-reviewed journals, are based on the non-destructive testing of samples using X-ray computed tomography.

After the subsequent semi-automated segmentation - i.e. the identification of the pore space and different minerals in the 3D scan - the thermophysical, hydraulic and mechanical properties of the rock sample relevant for geothermal projects are calculated using numerical methods. The method can be applied to cuttings (drill cuttings produced during the drilling process). The method thus offers the possibility of determining the relevant rock parameters over the entire drilling section and without the use of expensive core drilling methods, which can save costs on one hand and significantly improve the database for the subsequent numerical simulation of the geothermal plant on the other

We present the first results of the ongoing SimBoL-project. A selection of Carbonate cuttings were scanned with a high-resolution CT device. Those digital images were transformed into digital rock samples which are the basis of numerical simulations to determine the permeability, the heat conductivity and the mechanical rock properties. A first qualitative comparison with borehole data is presented.