The Potential for CO2 Geosequestration in Kenya: A Suitability Assessment of the Lamu Basin

Abstract

There is a consensus that current trends in climate change may be due to increasing concentrations of greenhouse gases (predominantly methane and carbon dioxide) from anthropogenic emissions. Among measures proposed for curbing this increase is Carbon Capture and Sequestration (CCS) in geological media. CCS incorporates three technologies comprising; (a) carbon capture, (b) compression and transportation, and (c) injection into geological media. This paper focuses on CO2 injection into geological media and its applicability to the Lamu basin. Sedimentary basins, which host the geological formations suitable for subsurface CO2 storage, are ideal to varied extents determined by such factors as their tectonic settings. A (coarse) basin scale suitability assessment of the Lamu basin was undertaken using the following parameters; size and depth, tectonic and structural settings, seismicity, geothermal-hydrodynamic regimes, basin maturity (based on hydrocarbon well density) and economic resources. The assessed attributes are used to constrain GIS data, delineating possible CCS trap areas with the production of a preliminary map of potential trap areas. Also, a suitability matrix table is generated in comparison with analogous basins such as the Alberta basin in Canada. Following this assessment, the Lamu basin can be considered geologically suitable for geosequestration given its stable tectonic settings, good depth and size. However, the western flanks of the basin and the coastal strip are unsuitable due to shallowness, population and protected zones respectively.