The figure above shows the comparison between the original seismic data and the seismic cross section after the envelope attribute is applied at the Inline 919. The envelope attribute is applied to show reflection to strong acoustic impedance contrast. This attribute is measure from complex trace of seismic signal used to locate significance seismic feature like lithology variations, faults and discontinuities. Sand layers and gas give response to envelop attributes and appear as bright spots in relation to acoustic impedance changes.

                In the seismic cross section that already has envelope attribute applied to it, there are a few observations that can be made. Firstly, the upper part of the seismic cross section has bright spots which could indicate gas is that specific area. The lithological boundary in the seismic cross section is also bright which could mean that the lithological boundary is made up of sand