Velocity-porosity and velocity-density relationship for shallow sediments in the Kerala-Konkan basin of western Indian margin

Abstract

During the expedition 01 of the National Gas Hydrate Program (NGHP), drilling and coring were carried out at one site in the Kerala-Konkan basin on the west cost of India to validate gas hydrate. Drilling/coring results show a homogenous sequence of oozes and explains that the reflector, which was identified as a bottom-simulating reflector (BSR) on seismic section, is mainly due to changes in formation density because of less clay content in carbonate-rich sediment. Downhole logs collected at this site are of good quality and have been used to establish empirical relationship between the P-wave velocity (V P ), S-wave velocity (V S ), density (ρ) and porosity (ϕ). The established relations show very good fit with high R2 value (>0.73), and can be used for further studies in this region. Well known existing empirical formulas between V P , V S , ρ and ϕ deviate significantly from our established relations.