Application of three-dimensional seismic texture analysis with special reference to deep-marine facies discrimination and interpretation: Offshore Angola, west Africa

In seismic stratigraphy, a seismic texture is an acoustic expression of the stratigraphic configuration of beds and thin beds that is related to depositional facies and reservoir properties. This study applies an amplitude co-occurrence matrix method to characterize seismic textures in a deep-marine setting offshore Angola (west Africa). Beginning with high-quality three-dimensional seismic data, the algorithm calculates textural homogeneity, contrast, and randomness by evaluating the amplitude co-occurrence matrix of a texture element at each sample location. Based on textural homogeneity, contrast, and randomness, a clustering analysis segments the regular seismic amplitude volume into different categories in a resulting thematic texture class volume. An integrated interpretation of the texture classes and regular amplitude characters, along with contemporary and outcrop analogs of deep-water systems, leads to the identification of several major facies; elements such as channel fill, levee, overbank, mass-transport complex, and marine shale in the lower Miocene-upper Pliocene stratigraphic interval. Sequential stratigraphic horizon slicing through the texture class volume indicates that the geomorphology and facies architecture have changed significantly from the early Miocene to the late Pliocene, which is instrumental in analyzing sequence stratigraphy, delineating the play fairway, and evaluating hydrocarbon potential. Sub-volume detection of distinct texture classes shows that different facies bodies are complex in extent, geometry, and connectivity in three dimensions, which provide critical seismic-scale constraints for geologically meaningful reservoir modeling and simulation.