ORIGINAL PAPER Hydrocarbon reservoir characterization of BAY^ field, deep-water Niger Delta using 3D seismic and well logs Oluseun Adetola Sanuade 1 & Adesoji Olumayowa Akanji 2 & Michael Adeyinka Oladunjoye 3 & Abayomi Adesola Olaojo 4 & Julius O. Fatoba 5 Received: 7 March 2015 /Accepted: 28 February 2017 # Saudi Society for Geosciences 2017 Abstract Three-dimensional seismic and well log data from nine wells were used for the characterization of BAY^ field in the deep-water, Niger Delta. Result shows that the field has a complex structural arrangement consisting of series of northeast-southwest-trending and northwest-dipping synthetic faults. Petrophysical evaluation of the available well logs helped in identifying 11 hydrocarbon-bearing sands noted as A1000, A1100, A1200, A2000, B2000, B2100, C3000, C3100, D4000, D4100, and E5000. Reservoirs A1000, A1100, A1200, A2000, B2000, C3000, and D4000 are gas- bearing sands while reservoirs B2100, C3100, D4100, and E5000 are oil bearing. The average effective porosity of these reservoirs ranges from 0.168 to 0.292; water saturation is es- timated to be between 0.177 and 0.59 and net-to-gross (NTG) ratio from 0.081 to 0.734. Considering the uncertainty in the input petrophysical parameters as well as structural uncertain- ty particularly in fluid contact, the total hydrocarbon reserves in the field were estimated to vary between 266.942 and 334.457 Bscf and 132.612 and 150.036 MMbbl for gas and oil volumes, respectively. Keywords Deep water . Synthetic faults . Net to gross . Reservoirs . Reserves Introduction The Niger Delta basin is a tertiary delta located on a marginal sag basin. It is one of the most prolific deltaic hydrocarbon provinces in the world formed during Paleocene to Pliocene age. Hydrocarbon in the province is mainly produced from sandstones and unconsolidated sands mostly within the Agbada Formation (Doust and Omatsola 1990). The deep- water Niger Delta region in a little more than a decade has been a beehive of exploration, development, and production activities and represents a major oil and gas province. The region holds several giant oil and gas accumulations with a lot of unexplored opportunities trapped in a variety of struc- tural styles spanning through the continental shelf to the con- tinental slope within the Nigerian Offshore depobelt. The di- verse and complex structural styles entrenched within the re- gion and the resulting uncertainty in the hydrocarbon volumes presented serious challenges to geoscientists and explorationists and thus requires the application of specialized interpretation techniques in defining the prevailing structural styles (Adeoti et al. 2014a, b; Amigun and Bakare 2013; Richardson 2013; Amigun et al. 2012; El-Mowafy and Marfurt 2008). The integration of 3D seismic and well log data has proven to be an important tool in the determination of structural framework and to detect reservoir petrophysical parameters such as porosity, water saturation, and locating hydrocarbon zones of a basin Oyedele et al. 2013; Onayemi and Oladele 2014). This work is therefore carried out to sys- tematically characterize the enlisted reservoirs in BAY^ field * Oluseun Adetola Sanuade sheunsky@gmail.com 1 Geosciences Department, King Fahd University of Petroleum & Minerals, Dhahran, Saudi Arabia 2 Geoexperts Nigeria Ltd, Rockstone Ville Estate, Badore, Ajah, Lagos, Nigeria 3 Department of Geology, University of Ibadan, Ibadan, Nigeria 4 Earth Sciences Department, Ajayi Crowther University, Oyo, Nigeria 5 Department of Geophysics, Federal University Oye-Ekiti, Oye, Ekiti State, Nigeria Arab J Geosci (2017) 10:151 DOI 10.1007/s12517-017-2941-0