Non-destructive X-ray imaging of the internal structure of geological cores is an important part of core analysis programmes. Such information is used to check core quality and integrity, locate regions for sub-sampling and orientate core sections correctly by comparing to the borehole logs. Traditionally, X-ray imaging is performed using either 2D transmission radiography or 3-D computed tomography (CT). However, radiography only gives single plane information and 3-D CT datasets can produce enormous volumes of data and typically at voxel resolutions of between 300 µm and 500 µm.
In this presentation we will showcase an innovative use of high resolution (<150 µm per pixel) laminography acquisition and reconstruction; and demonstrate how we have adapted it for geological applications using a number of case studies featuring both sediment and rock cores.
Laminography is an alternative X-ray scanning technique that can provide quasi 3-D information by resolving features on planes within the object. Laminography is a well-established technique that has gained renewed interest for scanning planar objects (e.g. circuit boards). A unique adaption of laminography scanning is deployed on cabinet-based high resolution X-ray CT systems and is shown to produce high resolution downcore views (or slabs) at a fraction of the time required for full CT and with significantly more detail compared to 2D radiograph. Furthermore, The laminography technique is extended to directly produce ‘unwrapped’ circumferential views of the core, allowing for example dip and bedding angles to be extracted without full CT scanning.
The use of innovative imagine techniques such as laminography provide new high resolution X-ray deliverables to the geoscience industry. Laminography offers lower data volumes and increased acquisition speed whilst delivering fit for purpose 360 degree information. The ability to deploy laminography on small cabinet-based systems now opens up the possibility of rapid onsite X-ray scanning.
