Search

The interpretation of subsurface fluid flow features in seismic reflection data is a key part of identifying the presence of hydrocarbon and active petroleum systems. Currently, this kind of study is mainly conducted utilizing offshore seismic reflection data with very limited cases utilizing onshore seismic reflection data. In addition, the Alamein basin is an area of prolific study in onshore Egypt, with most related studies concentrating on basin analysis and reservoir characterization. Therefore, in our study we aimed to make practical and effective use of onshore seismic reflection data with seismic attribute analysis to describe seismic facies, delineating and interpreting subsurface fluid flow features. The relatively vertical V-shaped and pipe or concave-up-shaped features with distorted reflections inside them are revealed through the analysis of variance, sweetness, chaos, instantaneous frequency and the RMS amplitude of seismic attributes. These subsurface fluid flow features are a product of mature source rock that migrates hydrocarbon vertically through faults (especially deep-seated faults) and fracture systems (fault and fracture-related subsurface fluid flow features). The classification scheme presented in our study could be implemented in the onshore case worldwide. [ABSTRACT FROM AUTHOR]

The current work aims to study the structural and facies characterizations of the Apollonia Formation carbonate reservoir by applying the curvature attribute and facies modeling. This reservoir is considered an unconventional, gas-bearing chalk reservoir located at the JDT field in the Abu El-Gharadig Basin, northern Western Desert of Egypt. The workflow begins by computing the curvature seismic attribute on the available 3D seismic data of the field. This is accompanied by the detailed sedimentological and petrophysical analysis of available core data and the distribution of the resulting facies log along the available 3D geological model. The results of the curvature attribute along the Apollonia "A5" layer showed faults traces more than three times the traces determined by the variance attribute along the same layer, with small horizontal spacing between faults about 230 m. This attribute is considered as the best attribute for determining subseismic resolution faults (SSRF) of the polygonal faults affecting the reservoir. The facies analysis indicated that this chalk reservoir is composed of four primary facie: Faceis A (clean chalk), Facies B (slightly argillaceous chalk), Facies C (argillacesou chalk) and Facies D (marl). These facies had been differentiated form each other based on the clay percentage, porosity and permeability. The best reservoir facies are Facies A (clean chalk) with a clay percentage 0–5%, average porosity 31% and average permeability 0.43mD and Facies B (slightly argillaceous chalk) with a clay percentages 5–15%, average porosity 23% and average permeability 0.12mD. Distributing these facies along the JDT field declares dramatically that facies characterization of the lower pay zone is better than the upper pay zone because of the abundance of A- and B-type facies along the lower zone. Consequently, a 3D geological model had been constructed which used for the determination of the best location of any further development well targeting primarily A- and B-type facies and for any future production and hydraulic fracturing operations. • Application of Curvature attributes for the structural characterization of highly faulted carbonate reservoir. • Construction of 3D facies modeling for the lithological characterization of the carbonate reservoir. • The impact of these method on the reservoir development. [ABSTRACT FROM AUTHOR]