As the demand for fossil fuels increases, reservoir characterization is becoming more and more important. By definition, reservoir characterization requires a thorough description of a reservoir using all the knowledge, methods, disciplines, and skills at hand. The output of reservoir characterization is a reservoir model that accounts for every aspect that affects a reservoir's ability to generate and store hydrocarbons. In order to identify structural and stratigraphic prospects and comprehend the rock and fluid properties within those prospects, the initial objective of any reservoir characterization inquiry is to give a high-quality image of the subsurface (Hossain et al. 2021). Reservoir geometry, including faults and facies variations that may have an impact on reservoir production performance, is taken into account during reservoir delineation. The physical characteristics of the reservoir, such as its porosity, permeability, water saturation, and pore fluid, are defined by the reservoir description.
A seismic attribute is any seismic data parameter that assists seismic interpreters in visually enhancing or quantifying characteristics of interpretation interest (Khayer et al. 2022). Seismic characteristics are a valuable tool for seismic interpretation. Seismic characteristics can be used to improve seismic data interpretation and are considered a powerful assist to seismic data interpretation. Seismic attributes are used to extract rock properties from observed seismic signals (Chopra and Marfurt. 2008; Torvela et al. 2013). They enable geoscientists to more quickly analyze faults and channels, determine the depositional environment, and unravel the structural deformation history. Seismic characteristics frequently aggregate subtle elements into groups by combining information from neighboring seismic samples and traces using a physical model (such as dip and azimuth, waveform similarity, or frequency content). A good seismic characteristic is either directly sensitive to the desired geologic feature or reservoir property of interest, or it allows us to describe the structural or depositional context and hence infer particular features or properties. One goal of seismic attributes is to quantify the amplitude and morphological traits perceived in seismic data using a system of deterministic calculations performed on a computer in order to capture the interpreter's pattern-recognition ability. For example, variance is a property that is used to identify or measure the coherency of the horizons; this also aids in the detection of faults because the area of low coherency indicates horizon fracture (Robinson and Davis 2012; Ashraf et al. 2020).
Seismic structural interpretation aids in deciphering the architecture of subsurface strata by imaging minute features of geologic structures such as faults, folds, fracture networks, and so on (Mandal and Srivastava 2018). It gives light on the architecture of hydrocarbon-bearing beds as a result. When obtaining accurate images of these geologic features from geophysical data, interpreters frequently face significant obstacles. The application of structural geology ideas to seismic data interpretation is critical for correctly recreating subsurface structures and comprehending their geometric and kinematic evolution. This has a significant impact on prospect generation and exploration. The interpretation and identification of sub-surface structural targets should always be supported by a complete understanding the regional tectonic framework of the area being aware of structural variability through space and time.
Due to the limitations of seismic resolution, accurate reservoir characterization has always been a tough undertaking. Dealing with diverse and heterogenous reservoirs, which are common in the Niger Delta, makes this task all the more important. As a result, the main reasons for low hydrocarbon recovery efficiency, are reservoir heterogeneities. Uncertainties regarding the lateral extent, distribution of reservoir properties (such as porosity, net pay thickness, fluid type and fluid saturation, etc.), and fault placements along the reservoirs are additional typical challenges in describing Niger Delta reservoirs (Inichinbia et al. 2014; Horsfall et al. 2017; Okeugo et al. 2018).
Because of the limitations of seismic resolution, reliable reservoir classification has always been difficult. Dealing with heterogeneous reservoirs, which are common in the Niger Delta, emphasizes the importance of this task. As a result, reservoir heterogeneities are the primary cause of low hydrocarbon recovery efficiency. Uncertainties about the lateral extent, distribution of reservoir properties (such as porosity, net pay thickness, fluid type and fluid saturation, and so on), and fault placements along the reservoirs are also common challenges when describing Niger Delta reservoirs (Inichinbia et al. 2014; Horsfall et al. 2017; Okeugo et al. 2018). This study merges structural interpretation with seismic attribute analysis in an effort to address some of these challenges in order to anticipate and locate hydrocarbon-bearing reservoirs in a field, Onshore Niger Delta.