Characterization of Gas Hydrates Reservoirs in Krishna-Godavari Basin, Eastern Indian Margin

Abstract

Seismic inversion and attribute analysis techniques are frequently used in oil and gas industries to characterize a hydrocarbon reservoir. The gas hydrate reservoir in the Krishna-Godavari basin, eastern Indian margin, by analysis of highresolution multi-channel seismic (MCS) data has been characterised. The model-based seismic inversion was performed to derive acoustic impedance (3220 m/s*g/cm3) followed by computation of seismic attributes for delineating the bottom simulating reflector or BSR, main marker for gas hydrates, and characterizing the hydrate-bearing sediments. The study shows the characteristics of BSR at a depth of ∼125 m below sea floor (mbsf), and hence the presence of gas hydrates. The high velocity, low amplitude, high instantaneous frequency and low sweetness indicate presence of gas hydrates above the BSR, whereas low velocity, high reflection strength, low frequencies and high sweetness imply free gas underlying the BSR.