Finding Deep Groundwater in East Africa with Oil Company Seismic and Drilling Data: Norwegian Company Ruden AS Discovery

     In 2005, Norwegian company Ruden Geo Solutions interpreted existing oil company seismic data from the 1960s and found the deep Kimbiji freshwater aquifer in Tanzania. Looking at old well data and seismic lines the company decided to test deeper groundwater sources. They first drilled too shallow and did not hit the water productivity desired until they drilled down to the Neogene-aged aquifer at 600m (1800ft) in depth. That is indeed very deep for a freshwater aquifer. They drilled three exploration wells and then joint-ventured with CDM Smith to drill 7 additional wells in order to better understand the aquifer. The project was then turned over for management by local water company personnel. The idea came from company head and hydrogeologist Fridtjov Ruden. Basically, no one knew this aquifer even existed. Water scarcity is a serious issue in the East African region, so this has been great for the people in the area. Recurring and enduring droughts are also not uncommon.

“The whole aquifer system contains some 5000km3 of water while the rate of recharge from the hinterland is in the order of 2 km3 per year (1 km3 of water represents an annual water supply for 5M people). The Neogene deposits of the Kimbiji aquifer system form a continuous freshwater aquifer that extends 0-3000m in depth and some 65km eastwards, under the Indian Ocean.”

The deep groundwater found in Tanzania appears to be a major source of water that can be used by the growing city of Dar es Salaam and surrounding areas for decades to come and these wells and further deep wells should be much cheaper than drilling shallow wells of much less volume which would require far more wells. Kenya is another country where such exploration for deep groundwater is set to occur. Ruden AS writes regarding the advantages of high volume and high production rate deep groundwater aquifers:

“Deep groundwater is economically competitive. Experience from deep aquifers being produced around the world show that the lowest production rate expected from deep boreholes is on average 33 liters/second, that is, 20 to 30 times the production rate of shallow wells in the Horn of Africa. At the same time, the cost of drilling the number of shallow wells to reach the same amount of water produced by deep wells can be as much as twice the cost of a deep well. Additionally, the use of oil exploration data to identify groundwater resources diminishes the geological and investment risk. Most of the economic risk has been already taken by the oil sector. Repurposing the data is also repurposing the heavy investment previously done by the oil industry.”

     Ruden AS also notes that exploration for deep groundwater is ongoing in Somalia where 80 oil & gas exploration wells have been drilled and more than 40,000 km of seismic lines have been acquired. They are mainly searching for freshwater at depths exceeding 400m (1200ft). Remote Sensing and data from SWALIM (Somalia Water and Land Information Management) are also being integrated into the exploration effort. The participation of Schlumberger, now SLB, provided Petrel and Techlog software for 3D modeling, seismic, and petrophysics interpretation.

     The process of exploring for and developing the deep groundwater is shown below, proceeding from data mining to groundwater modeling and flow studies to coordinating with local authorities and stakeholders.

     In Somalia Ruden and his company worked for three years just to get the geological information from the Ministry of Petroleum. Oil companies generally do not make such information available to the public since it could be used by competitors. Ruden had to convince Somali authorities that he had no interest in exploring for oil, especially since he had been involved in exploring for oil in Tanzania.

     Deep groundwater aquifers were discovered in East Africa in the 2010s. Challenges to developing them include the proximity of the aquifer to the areas of demand, water quality, and infrastructure availability.

 Future management challenges include the prevention of overpumping and other mismanagement of the groundwater resource.

 

 

References:

 

Big Oil Shares Data Maps to Unlock Fresh Drinking Water for Millions of Africans. Andy Corbley. Good News Network. February 13, 2025. Big Oil Shares Data Maps to Unlock Fresh Drinking Water for Millions of Africans

X-ray of the earth: Confidential oil data shows where vital water sources lie in Africa. Federica Di Sario. Euro News. January 26, 2025. X-ray of the earth: Confidential oil data shows where vital water sources lie in Africa | Euronews

Tanzania - The discovery of the Kimbiji Aquifer. Ruden AS. Tanzania - The discovery of the Kimbiji Aquifer

Somalia - Exploring for deep groundwater. Ruden AS. Somalia - Exploring for deep groundwater

Kenya - No food security without water. Ruden AS. Kenya - No food security without water