The most important source of water in rural Africa is groundwater, which is traditionally extracted from shallow aquifers, drawn or pumped from wells in weathered basement. To be able to explore groundwater in deeper targets different methods need to be utilised. In the late 1970’s and early 1980’s, the Kimbiji peninsula in Tanzania was subject to extensive hydrocarbon exploration. Seismic profiles were shot and exploration wells were drilled. No oil was discovered at that time, and the information was shelved. 40 years later this data made it possible to discover structures that were drilled for water.
Ruden Geo Solutions decided in 2005 to take a closer look into the deeper subsurface. They combined applied hydrogeology and data from the hydrocarbon industry resulting in the discovery of the Kimbiji aquifer, which is presently serving more than 2 million people with fresh water. This discovery was done entirely based upon information from hydrocarbon exploration conducted in the area.
Following the discovery of the Kimbiji aquifer, at the Kimbiji peninsula in Tanzania, a project was undertaken by the Government of Tanzania to verify the potential existence of a regional coastal aquifer system. In the late 1970’s and early 1980’s, the Kimbiji peninsula was the subject of extensive hydrocarbon exploration. More than 1100 km 2D seismic profiles, that were reprocessed to a depth of 2000 meter, and information form 6 exploration wells was used to improve the definition of the Kimbiji aquifer system.
Based on the discovery in Tanzania, Ruden Geo Solutions developed a search model for finding deep groundwater entirely based on this innovative combination of hydrocarbon exploration data in a groundwater context.
The use of hydrocarbon exploration data allows the hydrogeologist to look much deeper than is conventionally possible with standard approaches and methods of hydrogeology, mainly because the water sector alone does not have the resources to investigate at similar scales or depths.
The top few hundred meters of the subsurface environment is generally of limited interest to the hydrocarbon exploration programs, and hence, although shallow seismic data are normally acquired, they are not necessarily processed. In contrast, this upper/shallow section represents the target zone for deeper groundwater exploration. However, with no economic incentives, or because of confidentiality issues, the hydrocarbon industry will not volunteer to share this valuable information.
These are challenges that need to be overcome to make the search for new and deeper groundwater resources possible. How can it be made attractive for oil companies to share their data? And what can the water sector possibly mean for the oil industry in return?