Based in Ouagadougou with a team of qualified, multidisciplinary engineers and technicians, BERGEB has used Robertson Geo’s logging technology on a variety of projects.
In a recent study, BERGEB utilised Robertson Geo’s Full Waveform Sonic, with gamma, to determine lithological boundaries in sedimentary terrains in western Burkina Faso, West Africa.
This project was located in the south-eastern part of the Taoudéni Basin. They combined logging measurements (gamma ray and full-wave sonic) to determine the boundaries of the different geological layers.
The drilling was carried out using mud, and given its depth (greater than 1,000m), the cuttings did not reach the surface immediately. As there is a latency period between reaching a new layer and the cuttings arriving at the surface, it was decided to employ logging to determine the exact depth at which the lithological change occurred.
The key benefits of using the sonic log were that gamma ray values increase in clay layers and decrease in sandy layers, whilst the sonic wave propagation velocities varied depending on the type of rock. BERGEB observed an increase in wave velocity in the sandstones, while it decreased in the clays. The results successfully showed an alternation of clay and sandstone beds.
