Characterizing Hydrocarbon Reservoirs in Kenya’s Lamu Basin Leveraging Petrophysical and Rock Physics Approaches

The characterization of Lamu offshore reservoirs remains limited due to the absence of integrated studies combining petrophysical analysis and rock physics modeling. This study aims to enhance reservoir characterization, reduce exploration risks, and provide a framework for similar geological settin...

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Bibliographic Details
Main Authors: Dennis Ombati, John Githiri, Maurice K’Orowe
Format: Article
Language:English
Published: Wiley 2025-01-01
Series:International Journal of Geophysics
Online Access:http://dx.doi.org/10.1155/ijge/9536103
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Summary:The characterization of Lamu offshore reservoirs remains limited due to the absence of integrated studies combining petrophysical analysis and rock physics modeling. This study aims to enhance reservoir characterization, reduce exploration risks, and provide a framework for similar geological settings. Log data from three wells were analyzed to determine key petrophysical properties and evaluate rock physics models for lithology and fluid discrimination. Reservoir zones were delineated based on petrophysical parameters, including clay volume, porosity, hydrocarbon saturation, and gamma ray and resistivity responses. The selected reservoirs exhibited favorable characteristics, with low shale volume (0.07–0.26), high effective porosity (0.12–0.25), low water saturation (0.23–0.56), and a net thickness (18.95–43.22 m). Rock physics cross-plots (mu-rho vs. density, acoustic impedance vs. lambda-rho, and Vp/Vs ratio vs. acoustic impedance, among others) effectively distinguished hydrocarbon-bearing zones from brine-saturated sands and shales. Color-coded cross-plots further validated fluid discrimination, showing low water saturation and gamma ray values with high porosity in hydrocarbon zones. Gassmann fluid substitution analysis confirmed that replacing water with hydrocarbons significantly reduced density and had a more pronounced effect on compressional velocity than shear velocity. These findings highlight an integrated approach to minimizing hydrocarbon exploration risks, particularly in avoiding dry wells, and offer valuable insights for future exploration efforts in Lamu offshore and similar basins.
ISSN:1687-8868