Block 12B, Kenya
Block 12B is located on the Nyanza Rift, a part of the East African Rift System (EARS). The block is about 300km south of the recent oil discoveries in the Lokichar basin. The Nyanza Rift is an offshoot from the main eastern branch of the EARS.
Work to Date
In Oct/Nov 2012 the company, with its Joint Venture partner, carried out an airborne gravity-magnetic survey over Block 12B. The airborne gravity data confirmed an area of pronounced gravity low over the Nyanza rift. Preliminary computer modelling and interpretation of the gravity and magnetic data supported the view that the Nyanza Rift is underlain by a sedimentary basin of up to two to three kilometres thick. During April, May and June 2014 the Joint Venture participants carried out a 350-km 2D seismic survey over the Nyanza rift and, on the basis of these results, took the decision to go ahead into the second exploration phase.
The technical review of the 12B basin was completed in the third quarter of 2014 and revealed a number of leads and prospects, of which Ahero-A was provisionally identified as a potential drilling target for 2015.
The shallow basalts in the basin however have made the processing of the seismic extremely difficult and made identification of the basement and internal geometries of the sediment infill almost impossible to map.
As such the Joint Venture successfully negotiated an extension to the First Additional Exploration Period with the Government of Kenya which allows a comprehensive reprocessing sequence of the seismic data to be accompanied by a Full Tensor Gravity Survey (FTG) over the basin (see below). The latter will help firm up structural leads mapped from the reprocessed data such that viable drilling targets can be identified. The early reprocessing (as indicated on line 109 below) suggests that there is a Neogene basin at least 4,000m deep and of the same age as the prolific Lokichar basin (Early to Mid-Miocene). The commitment well is expected to be drilled in 2nd Quarter 2017.