GamaseisProcessing consists of scripts to read data in a SEG-Y format, performing amplitude correction, muting, velocity analysis, normal moveout correction, and stacking.

Velocity Analysis. In this section, we describe velocity analysis performed on the set of NMO uncorrected traces or on the imperfect NMO corrections.

NMO correction is performed using the previously chosen parameters used in the velocity analysis. Velocity from the chosen result is associated with a linear relationship; therefore, the velocity is continuous each time.

SEISGAMA is a free seismic reflection data processing software program that has successfully processed 2D seismic data for amplitude correction, muting, F-x and F-K domain transform, velocity analysis, NMO correction, and trace stacking.

Caption: Figure 5: Velocity analysis result (b) from shot-gather on (a).

Figures 5(d) and 6(d) show that there is an increase in [X.sub.max] at a few azimuths; the fold corresponding to these bins is low enough that the bins can be ignored for

velocity analysis. Figure 6 also shows that the fold at [X.sub.min] is 7, which is greater than the minimum number of traces needed for

velocity analysis.

The differential interformational velocity analysis, 'DIVA', carried out along four seismic sections indicated mainly minor 'DIVA' anomalies.

Results of the differential interformational velocity analysis have further confirmed the existence of velocity anomalies resulting from changes in rock type and or fluid content, which substantially enhances the magnitude of the anomaly when the presence of gas is indicated.