Characterization of reservoirs and depositional study of J-P Field, shallow offshore of Niger Delta Basin, Nigeria

Abstract

Well log data interpretation was carried out over J-P Field in the Niger Delta, Nigeria. This was done with a view to characterizing the reservoirs based on the estimation of petrophysical parameters and to assessing the environment of deposition in J-P Field. Seven reservoirs were mapped and correlated across the four drilled wells in J-P Field. Petrophysical parameters such as porosity, volume of shale, water saturation and hydrocarbon saturation were estimated. In addition, depositional environments of each reservoir in J-P Field were determined based on the gamma ray responses. This study reveals that the range of petrophysical parameters across the delineated reservoirs; for porosity varies from 19 to 21%, thickness varies from 24 to 122 m, volume of shale varies from 15 to 29%, water saturation varies from 22 to 60% and hydrocarbon saturation varies from 40 to 78%. The depositional environment was interpreted as comprised of prograding deltas, transgressive marine sands, fluvial channels and deltaic settings. It is concluded that J-P Field has a porosity range varying from good to very good in quality and high hydrocarbon saturation of oil. Furthermore, the study revealed that J-P Field falls within the marginal marine depositional environment.

Keywords

• Petrophysical analysis
• Reservoir characterization
• Depositional environment
• Well logging interpretation
• Niger Delta