Seismic Attribute-Based Characterization of Heterogeneous Sand Reservoirs in the Niger Delta Basin, Nigeria
I. H. OpiriyaboA. D. Onengiyeofori
J. Amonieah J. A. Mfonobong
Jul 2026· African journal of environment and natural science research· Vol 9, pp. 113· 0 citations· 16 references
Abstract
Accurate characterization of heterogeneous reservoirs in the Niger Delta remains challenging because conventional seismic interpretation alone often fails to resolve complex structural features and lateral variations in reservoir properties. These limitations increase uncertainty in identifying hydrocarbon-bearing intervals and predicting reservoir continuity. This study integrates structural interpretation with seismic attribute analysis to improve reservoir characterization and hydrocarbon prospect identification in the onshore Omicron Field, Niger Delta, Nigeria. High-quality 3D seismic data, check-shot data, and well logs from four wells were integrated to delineate reservoir units, correlate lithologies, interpret faults and horizons, generate time and depth structure maps, and analyse coherency and root-mean-square (RMS) amplitude attributes. Two laterally continuous reservoir sands (Sand A and Sand B) were identified across the field, together with five major faults and two key seismic horizons. Structural interpretation revealed a fault-supported NW–SE-trending anticlinal closure, with structural highs concentrated in the central part of the field and structural lows toward the northwest. RMS amplitude maps show pronounced high-amplitude anomalies in the western part of both reservoirs, indicating potential hydrocarbon accumulation, while Sand B exhibits stronger amplitude responses than the shallower Sand A. The mapped fault-controlled closures and bright-spot anomalies collectively indicate favourable hydrocarbon potential within the study area. The results demonstrate that integrating seismic attributes with structural interpretation reduces uncertainty in reservoir characterization and provides a robust workflow for evaluating heterogeneous reservoirs and identifying exploration targets in the Niger Delta.
This study presents a comprehensive reservoir characterization of Sand F in the "DABS" Field, located within the coastal swamp depositional belt of the Niger Delta Basin. The primary objective was to evaluate hydrocarbon potential and delineate prospective drilling locations using integrated seismic interpretation and petrophysical analysis. The available data for this study are 3D seismic, well logs (DABS-01 to DABS-06), and checkshot data from DABS-04. The methodology used includes fault interpretation, well log correlation, time-to-depth conversion, map generation, identification of reservoirs/prospects, and volumetrics. Seismic interpretation of 21 inline sections revealed a structurally complex area dominated by listric normal faulting typical of the Niger Delta extensional regime. Seven hydrocarbon-bearing sand bodies (A-G) were delineated, with Sand F selected as the primary reservoir target based on its lateral continuity and hydrocarbon presence in wells DABS-01, DABS-04, and DABS-03. A fault-dependent structural trap with a bottom water drive mechanism characterizes the reservoir. We established the oil-water contact at a depth of −10,565 ft subsea. Volumetric analysis using depth-volume relationships estimated a gross rock volume of 35,276 acre-feet. We estimated the Stock Tank Original Oil In Place at 25.3 MMSTB and Estimated Ultimate Recovery (EUR) at 10.2 MMSTB. In addition, we identified one high-potential prospect: a northeast prospect targeting depths of −8,880 to −8,950 ft and a southeast lead at −10,560 ft. These locations were optimized based on their structural positions relative to the mapped faults and the established oil-water contact (OWC). This integrated approach demonstrates the effectiveness of combining seismic interpretation with petrophysical analysis for reservoir characterization in structurally complex Niger Delta settings, providing a robust framework for field development planning.
G. Oke, B. A. Ayegbusi· SPE Nigeria Annual Internati...· 0 citations
The 21st-century global energy demand necessitates advanced reservoir characterization to optimize hydrocarbon exploitation and minimize drilling risks. This study integrates petrophysical analysis and multi-attribute seismic interpretation to evaluate the hydrocarbon potential of the GOTO Field in the Niger Delta. Using suites of well logs from seven wells and 3D post-stack seismic data, four reservoir sands (A, B, C, and D) were delineated and correlated across the field. Petrophysical evaluation reveals that Sand A is the most prospective unit, exhibiting excellent reservoir quality with average effective porosity of 29.3%, permeability reaching 758 mD, and moderate water saturation. Sands C and D show moderate quality with localized potential, while Sand B is identified as predominantly water-saturated (91–96%). Seismic interpretation identified major structural traps, including rollover anticlines and fault-assisted closures. Analysis of seismic attributes—including RMS Amplitude, Average Energy, and Sweetness—revealed strong anomalies in Sands A, C, and D that conform to structural highs, serving as direct hydrocarbon indicators (DHIs). The high degree of consistency between petrophysical data and seismic attribute responses demonstrates that this integrated quantitative approach significantly reduces exploration uncertainty and improves the precision of reservoir evaluation in complex deltaic environments.
Igonoh David Asuba, E. Omokenu, I. Sonny· Nigerian Journal of Physics· 0 citations
The Maduky Field, situated within the Coastal Swamp depobelt of the Niger Delta Basin, represents a structurally complex and geologically heterogeneous marginal field with untapped hydrocarbon potential. This study integrates 3D seismic interpretation, well log correlation, sequence stratigraphy, and petrophysical analysis to characterize its reservoir architecture and evaluate hydrocarbon volumes. Structural mapping reveals prominent listric growth faults and rollover anticlines that define three main field compartments, each with distinct depositional and trapping characteristics.
Sequence stratigraphic analysis, guided by five regionally correlated Maximum Flooding Surfaces (MFSs), delineates Genetic Sequences and system tracts (HST, TST, LST), each with unique parasequence stacking patterns and reservoir geometries. The highstand and lowstand system tracts host the most prolific reservoirs, characterized by clean, coarsening-upward sand bodies with high net-to-gross ratios and favorable porosity-permeability relationships. Petrophysical evaluation across five wells indicates effective porosity values of 20–34%, permeability ranging from 2.50 to 18 mD, and low water saturation (8–35%), confirming reservoir quality suitable for commercial exploitation. Crossplots further demonstrate the controls of porosity and depositional environment on fluid distribution and reservoir performance.
The study identifies key hydrocarbon-bearing units sealed by marine shales associated with MFSs and quantifies Stock Tank Oil Initially In Place (STOIIP) across fault blocks, highlighting potential development zones. These insights support the redevelopment of Maduky Field and provide a scalable model for optimizing marginal field performance in mature deltaic basins.
S. Onyekuru, Reginald Chinonso Maduka, T. C. Anyanwu et al.· Romanian Journal of Petroleu...· 0 citations
Fractured carbonate reservoir is an important area of hydrocarbon exploration and development. Their reservoir spaces, formed through multiple phases of karst processes, having complex morphology and are highly interconnected. These make accurate identification and prediction particularly challenging. Seismic attribute analysis is a key method linking seismic reflection characteristics with subsurface geological features, and it can quantitatively extract response characteristics such as amplitude, frequency, and phase from large amounts of seismic data, and provides effective support for the identification of such reservoirs. This study systematically reviews the classification system of seismic attributes, proposes a three-class attribute classification based on geological target identification, and constructs a hierarchical progressive reservoir prediction technology chain. We also analyzes the limitations of applying single attributes using seismic attribute case studies. Furthermore, we summarizes the core concepts and practical achievements of multi-attribute fusion and anticipates the future directions of application trends and intelligent technologies in this field, which help to provide the systematic theoretical references and practical insights for the efficient identification and prediction of fractured carbonate reservoirs.
Yi Xia· Theoretical and Natural Scie...· 0 citations
Hydrocarbon production reduces pore-fluid pressure and increases the effective stress acting on the grain framework of reservoir rocks. This process induces reservoir deformation, compaction, and stress redistribution, often manifesting as fault reactivation, surface subsidence, wellbore instability, and 4D seismic time shifts. In this study, we present a geomechanical and structural interpretation of production-induced stress changes in the Kolo-Creek Field, Coastal Swamp Niger Delta, Nigeria. The analysis integrates 3D seismic interpretation, geomechanical evaluation, well-log analysis, and production data. Time-lapse seismic surveys acquired in 1997 (base) and 2009 (monitor) show clear 4D responses with a root-mean-square repeatability ratio (RRR) of 0.38, indicating excellent survey repeatability. The seismic interpretation reveals fault reactivation and fracturing associated with production-induced stress changes. Geophysical well logs from seven wells were used to delineate and correlate three reservoir zones (Sand A, Sand B, and Sand C). Petrophysical analysis indicates low shale content ranging from 7.74–37.44%, high porosity values between 0.19 and 0.36), and excellent permeability varying from 375–3327 mD, which is consistent with high-quality, coarse-grained sandstones. Production and pressure data provided by SPDC show a decline from 1592.55 to 400.34 bbl/day and from 4766 to 3103 psi over 12 years, respectively, corroborating with the geomechanical interpretation. The integration of geomechanics with seismic and structural analysis demonstrates the influence of reservoir stress changes on fault behavior and reservoir performance, providing insights to optimize production and manage risks in similar deltaic settings. This study could lead to Wellbore Stability Management; Using stress change predictions to guide well placement and drilling orientation, minimizing risks of shear failure, casing deformation, and production losses.
Orji Stephen, Tamunobereton-ari Iyenomie, Amakiri Chinoye et al.· Petroleum Science and Engine...· 0 citations
The purpose of this paper is to compartmentalize the rock units that make up the reservoir into different compartments to identify units with hydrocarbon potential. Niger Delta Basin is a rift basin characterised with complex geological structures and lithological heterogeneity, thereby demanding careful and systematic approach for successful results. Integrated seismic attribute studies provide the needed platform for compartmentalizing the various reservoir units for optimum hydrocarbon production.
Attributes such as Extract Value (the raw amplitude of input seismic), Arc Length, Average Magnitude, Root Mean Square (RMS), Average Energy, Maximum Amplitude, Half Energy, Positive to Negative Ratio and Sum of Magnitudes were adopted to study the reservoirs for the purpose of understanding the interplay of all the elements of petroleum system. These attributes were derived through various mathematical and statistical manipulations on the seismic amplitude and each were linked to specific reservoir petrophysical parameters such as fluid content, porosity, thickness and sand/shale content. To resolve ambiguities in the interpretation of results, more than one attribute were used for single rock properties in order to address the problem of attribute limitation and interpretation ambiguities.
The result revealed different reservoir compartments with/without hydrocarbon and lithologic heterogeneity indicating that reservoir properties are not the same throughout the zone. Regions with high attribute values above the background level were interpreted as complex geological structures hosting hydrocarbon especially when they are in conformity with structures capable of habouring hydrocarbon. Further, the material parameters relating to changes in porosity, thickness and net-to-sand ratio were delineated using different seismic attribute maps. Understanding factors controlling reservoir compartmentalization is critical for identifying optimum well location and for executing secondary recovery of hydrocarbon in complex reservoirs.
The originality lies in the ability of the work to identify and recommend the most appropriate attributes for a specific reservoir property for the study of reservoir compartmentalization as most of the published studies did not use most of the attributes, or compare them with each other. The study applied at least two attributes to a particular reservoir property to reduce uncertainties in the results and to illustrate how one rock property may account for multiple seismic attribute changes. Therefore, the study concluded that integrating several attributes of significance are crucial tools for compartmentalizing reservoir units in the Niger Delta Basin and any other basin around the world.
Abdulbariu Ibrahim, W. O. Raji· World Journal of Engineering· 0 citations
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