Deformation bands (DB) are known to influence porosity and permeability in sandstones. This study aims to predict the occurrence of DB and to quantify their impact on reservoir properties based on field measurements in the steeply dipping limb of a kilometer-scale fold in Yasamal Valley, western South Caspian Basin. An integrated approach of characterizing bands and their effect on reservoir properties included measurements of natural gamma radioactivity and permeability using portable tools, along with bed dip and the count of DB across distinct facies. A set of core analyses was performed on outcrop plugs with and without bands to estimate the alteration of rock properties at the pore scale. Interpretation of outcrop gamma-ray data indicates the absence of bands in Balakhany sandstones containing shale volume greater than 18% for unconsolidated and 32% for calcite-rich facies. A high amount of calcite cement appears to increase the number of DB. A poor, positive trend between bed dip and DB concentration was identified. We show that net to gross, defined as the thickness fraction of sandstone bound by mudstones, is among the parameters controlling the occurrence of bands. Samples containing a single DB show a 33% and 3% decrease in permeability and porosity, respectively, relative to the host rock. We reveal a new set of lithological and petrophysical factors influencing DB occurrence. This study offers a direct tool that can be applied in subsurface reservoir analogs to predict the occurrence and concentration of DB and estimate their influence on rock properties.

With the advent of stereoscopic data such as as Landsat and SPOT imagery, these methods have been applied to satellite data and used to successfully obtain quantitative measurements over large areas. On this connection, these methods have assisted considerably in fault analysis considerations and detection hydrocarbon seeps in surface of the Kura basin which are considered main oil and gas bearing region in onshore Azerbaijan. The satellite imagery interpretation drew upon knowledge of structural geology and geomorphology and detected hydrocarbon seeps related to fault and mud volcano geomorphology. The main objectives are to determine the role of faults and mud volcanoes within the geologic structure of the study regions and to guide future oil exploration. Remote sensing to detect hydrocarbon seepage onshore allowed recognition of marginal and sub-marginal low-relief structural prospects and stratigraphic traps that is overlooked by reflection seismic surveys. Remote sensing data and images were integrated in hydrocarbon exploration programs with other exploration data such as seismic surveys, well logs, gravity surveys, and other geologic-geophysical investigations. Analysis of satellite data allowed to determine the geometry of the fault system and around them distributions of hydrocarbon seeps and to predict hydrocarbon potential of the Kura basin.

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