Design of a Core Holder That Allows Highly Detailed Computer Tomography Scans in 3 Dimensions

Abstract

In the case of advanced Computer Tomography scanning of rock core samples, there’s need for a good core holder. The core holder contains the rock cores and neutralizes temperatures and pressures against the CT-scanning system. In the case of the core holder that is used for the core flood experiments, there are several factors that play against each other. The core holder that will be used for the Experiments at the GZB - International Geothermal Centre, will support the core to be flooded by different types of gases and liquids, while having the core experiencing temperatures and pressures that can be expected at the considered reservoir depth. This is expected to be around 150 degree Celsius and 200 bars of pressure. The real challenge is to make it also fit in the TC scanner, letting the X-rays through with as little adverse influence as possible, and allow for movement around and along the vertical axis. The CT scanner that will be used is going to give a representative image of all pores down to 1 µm, which means that it is sensitive to any disturbances in both movement and in choice of material. This means that choice of material is important to achieve a stable and transparent core holder. Favored materials for this kind of applications are PEEK, Carbon fiber and Aluminum, due to the low atomic number. When it comes to the size, the core holder is limited by the space left in the CT scanner, but should be compatible with smaller sizes. This means that the core holder is expected to accept cores that are less than 100mm in diameter, and lengths up to 600 mm long.