Methods of generating synthetic acoustic logs from resistivity logs for gas-hydrate-bearing sediments

Methods of predicting acoustic logs from resistivity logs
for hydrate-bearing sediments are presented. Modified time
average equations derived from the weighted equation provide a
means of relating the velocity of the sediment to the resistivity of
the sediment. These methods can be used to transform resistivity
logs into acoustic logs with or without using the gas hydrate
concentration in the pore space. All the parameters except the
unconsolidation constants, necessary for the prediction of acoustic
log from resistivity log, can be estimated from a cross plot of
resistivity versus porosity values. Unconsolidation constants in
equations may be assumed without rendering significant errors
in the prediction. These methods were applied to the acoustic
and resistivity logs acquired at the Mallik 2L-38 gas hydrate
research well drilled at the Mackenzie Delta, northern Canada.
The results indicate that the proposed method is simple and
accurate.