Oil and Gas Exploration History in Kenya
Petroleum Exploration in Kenya begun in the 1950’s with the first well being drilled in 1960. British Petroleum (BP) and Shell began exploring in Kenya in 1954 in the Lamu Embayment where they drilled ten wells. None of the wells were fully evaluated or completed for production despite several indications of oil staining and untested zones with gas shows.
In Mandera Basin, Frobisher Ltd., Adobe Oil Company and Burmah Oil Company conducted photo geological field geology, gravity, aeromagnetic and seismic surveys that did not materialize into drilling programs.
In 1975, several consortia acquired acreage in upper part of Lamu Basin. Texas Pacific et al drilled Hargaso-1 in 1975 and encountered oil and gas shows in the Cretaceous rocks. In 1976 Chevron and Esso drilled Anza-1 and Bahati-1 wells in the southern part of Anza Basin. The drilling mud of both tests was suspected of having hydrocarbons and microfossils that contaminated the geochemical and cuttings respectively.
An interest in the offshore portion of the Lamu Basin resulted in the drilling of three deep wells, Simba-1, Maridadi-1 and Kofia-1 by a consortium of Cities Services, Marathon and Union in 1982. Seismic data revealed that salt diapiric structures were present along the Kenyan margin.
In 1986, the petroleum exploration and production legislation in Kenya was revised to provide suitable incentives and flexibility to attract international exploration interest in the country.
In 1986 the Government of Kenya entered into a joint venture exploration programme with Petro-Canada International Assistance Corporation. Seismic work was conducted and Kencan-1 was drilled to test deeper strata on the structure adjacent to Garissa-1 well.
A group of companies led by Amoco and Total drilled ten (10) wells, 8 of them in Anza Basin and 2 in Mandera Basin between 1985 and 1990. The wells were dry but with indications of oil and gas. Total exploration drilled Ndovu-1, Duma-1 and Kaisut-1 in North Anza Basin while Amoco drilled Sirius-1, Bellatrix-1 and Chalbi-3 in the Northwest of Anza Basin and Hothori-1 well in South Anza Basin.
Amoco farmed out 50% of its interest to Shell who drilled Eliye Springs-1 and Loperot-1 located west of Lake Turkana in a Tertiary Rift Basin. The Loperot-1 well penetrated a lacustrine source rock with high Total Organic Carbon content (TOC) and recovered water and waxy oil on a repeat formation test (RFT) from Miocene sandstone interval.
While none of these wells encountered commercial reserves, fluorescence and gas shows were reported in Hothori, Endela, and Ndovu wells. Biostratigraphic studies suggest that these wells may not have penetrated deep to test the Neocomian-Lower Albian sediments which comprise the source reservoir, and seal within Sudan rift basins.
In 1991, National Oil initiated an in-house study of the Lamu Basin as part of a long-term strategy to re- evaluate the existing geological, geophysical and geochemical data relating to each of the sedimentary basins in Kenya. The Lamu Basin study was completed in 1995. Based on the above reports Kenya subdivided the Lamu embayment (both onshore and offshore) into ten (10) exploration blocks, each with a specific exploration play. Two (2) more exploration blocks have been created since the year 2001.
Promotion efforts generated new interests in the offshore Lamu Basin, and resulted in the signing of seven (7) Production Sharing Contracts covering blocks L5, L6, L7, L8, L9, L10 & L11 between 2000 and 2002. A total of 7884 km of 2D seismic data covering Blocks L5, L6, L7, L8, L9, L10, L11 & L12 was acquired offshore Lamu Basin by Woodside between August and October 2003.
In August 2000 the Corporation commissioned the Tertiary Rift Study, which was completed in March 2001. Tertiary rift study led to quantification of potential source and reservoir rock units in the study area as well as the petroleum system at play in the sub-basins.
National Oil has a Data Centre for storage of seismic data, well logs, well reports, other oil exploration reports and aeromagnetic as well as gravity data which has been obtained in this country to date through petroleum exploration activities. In addition, National Oil has set up cores and drill cuttings storage facility in which the rock samples retrieved during petroleum exploration in this country from 1960 to date are stored for use by those carrying out exploration.