Mapping hydrocarbon microseepage prospect areas by integrated studies of ASTER processing, geochemistry and geophysical surveys in Assam-Arakan Fold Belt, NE India

Abstract

Long-term microseepage of hydrocarbons creates a reducing environment in the near-surface soil and sediment cover inducing an array of diagenetic alterations such as bleaching of red beds and increasing abundance of ferrous, clay and carbonate minerals. Spectral enhancements of satellite images have effectively been used in microseepage-induced mineral mapping in arid regions. However, the present study aims to delineate microseepage-induced mineral alteration areas in Assam-Arakan Fold Belt (AAFB) in the north-eastern part of India, dominated by humid climate and heavy precipitation. The study uses an integrated approach consisting of advanced spaceborne thermal emission and reflection radiometer (ASTER) image processing, geochemistry, gravity and magnetic data. ASTER image processing involves specialized band ratios (BRs), false colour composite (FCC) and spectral angle mapping (SAM). Integration of remote sensing, geochemistry, gravity and magnetic anomaly data successfully delineates microseepage prospect areas in the basin. The study would provide important advantages in hydrocarbon exploration strategy in similar basins around the world.

Keywords

• Hydrocarbon
• Microseepage
• ASTER
• Gravity
• Magnetic