Coblending of seismic attributes for interpretation of channel geometries in Rence Field of Niger Delta, Nigeria

Abstract

Coblending of seismic attributes is used in the interpretation of channel geometries in the Rence Field of Niger Delta, Nigeria. We aimed at seismically defining the geometries of hydrocarbon reservoirs with particular emphasis on channels in the shallow marine (offshore) Niger Delta. The coblending application enhanced the ease of detection and the continuity of the channels, leaving the channel environs unchanged. The result of the seismic facies analysis revealed that the Rence Field can be distinguished into two seismic facies, namely, layered complexes and chaotic complexes. The result of well to seismic ties revealed high- and low-amplitude reflection events for sand and shale units, respectively. Seismic structural interpretation of the Rence Field revealed 4 major regional faults and 12 minor faults. Seven of the faults were antithetic, and the rest were synthetic faults. One mega-channel feature that trends east–west was identified in the attribute maps generated. It was characterized by sinuosity of 1.3, with a length of 22,500 m, and a distance of 17,500 m. The average depth of the channel was approximately 170 m with amplitude of 1670 m and the wavelength as high as 7640 m. A depositional model generated from the attribute maps indicated a prograding fluvial environment of deposition. The attribute map also determined that there was shifting in the location of barrier bars within the area. This shifting could be attributed to the growth fault mechanism. At the stoss side of the sinusoidal channel, there were prominent sand point bar sequences. The petrophysical analysis of the well data revealed 90% net-to-gross, 28% porosity, 27% volume of shale, and 24% water saturation indicating that the reservoir was of pay quality. Based on the petrophysical analysis, results, and identification of channel deposits, the study area proved highly promising for hydrocarbon exploration.

Seismic analysis of the gas hydrate system at Pointer Ridge offshore SW Taiwan

“…We applied multi-attribute analyses including co-blending of seismic attributes and neural network technology to better detect critical geological features. Co-blending of seismic attributes can visualize several seismic attributes at the same time and it has been introduced as a powerful way to enhance the contrast between the geologic targets and the background (Taner, 2001;Ferguson et al, 2010;Chopra and Marfurt, 2008;2011;Barnes et al, 2011;Chinwuko et al, 2015).…”

“…It has been suggested that using a seismic attribute alone is inefficient to detect subsurface geologic features of a natural gas hydrate system (Ligtenberg, 2003). In addition, Chinwuko et al (2015) further suggests that co-blending of seismic attributes including the energy, impedance, and the similarity can enhance, and thus allow more efficient interpretation of sandy channel deposits. For example, the edge of the channels is often characterized by high energy, high impedance contrast, and low similarity compared to the surrounding sediments.…”

Investigation of Layer Thickness and Groundwater Potentials in Federal University Gusau and Its Environs, Zamfara State, Nigeria

“…The apparent resistivity values acquired from the measurement were plotted against half the current electrode spacing on a bi-logarithmic graph in order to determine the apparent resistivities and thicknesses of various layers penetrated. Some many researchers have written on the need and uses of Schlumberger method in groundwater investigation (Udensi, and Salako, 2005;Mohammed, 2007;Anakwuba et al,2014;Chinwuko et al, 2015;Osele et al, 2016;Chinwuko et al, 2016 and others). An iterative software computer program called the (Win-Resis).…”

Seismic geomorphology and stratigraphic trap analyses of the Lower Cretaceous siliciclastic reservoir in the Kopeh Dagh-Amu Darya Basin

“…In fluvial reservoir analysis, interpretation of fluvial style, shape, arrangement and distinction of sand-filled from mud-filled channels is the key elements for recognition of reservoir architecture (Carter 2003;Davies et al 2007, b;Posamentier et al 2007;Brown 2011;Miall 2014;Torrado et al 2014). In addition, understanding depositional systems in plain view is very important for prediction of sandstone reservoirs, because the palaeogeomorphology and sediment supply can control patterns of their spatial dispersal Zeng 2010;Zhu et al 2013;Chinwuko et al 2015;Eichkitz et al 2015;Wang et al 2016). Therefore, we use seismic geomorphology techniques to evaluate the geological features and ancient buried geomorphological surfaces.…”