Vol. 10(1), pp. 1-13, January, 2019 DOI: 10.5897/JPGE2018.0300 Article Number: D049C7059749 ISSN: 2I41-2677 Copyright ©2019 Author(s) retain the copyright of this article http://www.academicjournals.org/JPGE Journal of Petroleum and Gas Engineering Full Length Research Paper Analysis of shaly sand reservoir rocks in the eastern Niger Delta Basin using geophysical well logs Fozao K. F. 1,2* , Djieto-Lordon A. E. 1 , Ali E. A. A. 1 , Agying C. M. 1 , Ndeh D. M. 3 and Zebaze Djuka M. K. 1 1 Petroleum Research Group, University of Buea, P. O. Box 063, Buea, Cameroon. 2 Department of Petroleum Engineering, School of Engineering (NAHPI), University of Bamenda, Bamenda, Cameroon. 3 Arab Center for Engineering Studies (ACES)-Abu Dhabi, Industrial City of Abu Dhabi (ICAD) 1, Abu Dhabi, UAE. Received 7 October, 2018; Accepted 29 November, 2018 Shales in the reservoir causes complications for the petrophysicist because they generally are conductive and mask the high resistance characteristic of hydrocarbons. Data from a suite of well logs were used to estimate the effect of reservoir shaliness on petrophysical parameters of some reservoir rocks of the eastern Niger Delta Basin. The log section was digitized using Neuralog software. Delineation of the productive clean and dirty formations, as well as mapping of the fluid contents of the possible reservoir zones was carried out using Interactive Petrophysics software. Fifteen shaly sand bodies were identified. It was observed that, shale correction leads to a significant change in petrophysical parameters. The results obtained indicate that, the Simandoux and Indonesian models used for the study are both suitable for water saturation, and hydrocarbon saturation analysis in shaly sands of this part of the Basin. The porosity results for the Indonesian and Simandoux models gave, respectively 0.14-0.23 and 0.22-0.28, while the hydrocarbon saturation results are 0.650-0.908 and 0.650- 0.911 with permeabilities values of 1487.442-8881.697 mD and 1568.532-7451.592 mD for uncorrected and corrected permeability, respectively. Thomas-Stieber model shows that shale distribution in sands of the eastern Niger Delta Basin is mainly structural with few of disperse and laminar ones. Key words: Reservoir rock, Shaly sands, petrophysical parameters, well logs, models. INTRODUCTION The present local and global increase in demand for energy has placed both pressure and greater challenge to increase energy supply. Most of this energy is derived from hydrocarbon resources. In an oil prone area like the Niger Delta, even though hydrocarbons are within the subsurface, they cannot impulsively gush to the surface when penetrated by a production well (Aigbedion and Iyayi, 2007). On the contrary, most reservoir hydrocarbons reside in the pore spaces or open fractures of sedimentary rocks like sandstones. To produce them, detailed geological, petrophysical knowledge and data are needed to guide the placement of the well paths (Stat Oil Research Group, 2003). This can consequently help to optimize hydrocarbon recovery, and to improve *Corresponding author. E-mail: kfozao@gmail.com. Tel: +237 675 397 789. Author(s) agree that this article remain permanently open access under the terms of the Creative Commons Attribution License 4.0 International License