Petrophysical Evaluation of the Reservoir in the K - Field, Offshore Ghana

Abstract

Reliable assessment of the petrophysical properties of hydrocarbon-bearing reservoirs is essential for the estimation of hydrocarbon reserves, identification of good production zones, and assessing the need for hydro-fracturing jobs. The K-Field although discovered in the 1970s is yet to be developed. In this study, well logs from the wells drilled in this field were analysed with the primary objective of determining the petrophysical properties of the reservoir zones using various estimation models. From the log readings, the reservoir sands containing hydrocarbons in the field are found to be located at the Mid Turonian (90Ma)-Intra Upper Albian (96.5Ma) and Intra Upper Albian (98Ma). The porosity was determined using the density log and crossplots. Archie and Simandoux correlations were utilized in the determination of the water saturation. Permeability was estimated using Timur, Tixer and Coates correlations. The findings after the petrophysical evaluation indicate that the wells entered formations with good reservoir quality in terms of porosity, which ranges from 16.12% to 20.97%. In relation to hydrocarbon saturation and permeability, two of the wells gave better results suggesting that they were drilled through the productive part of the reservoir. Nonetheless, the average permeability of the reservoir is estimated to be very low. This suggests that in the field development planning, well stimulation methods should be incorporated to aid the ability of the reservoir rocks to transmit fluids into the production wells.