GATE-2018 (24) :Wyllie – Time average equation

CSIR-NET 2012

101 (B). The dip of a layer is 60° and its RMS velocity is 3585 m/sec. Then the stacking velocity is 

A) 6000 m/s                        

B) 7580 m/s                   

C) 7170 m/s                     

D) 3585 m/s

Solution:

V_stack= is the velocity required to best stack the data using the best fit hyperbola over the available offset range.

For horizontal layers and small offsets ‘V_stack’ should equal to ‘V_rms’ .

For dipping layers, velocity is required.

Formula:

V_stack= V_rms/cosϴ --------------------(1)

V_rms= 3585 m/s

ϴ=60˚

Therefore , V_stack =  3585 /cos60˚

                              =(3585 *2)                

                                                           (cos60˚=1/2)

V_stack=7170 m/s