An alternative workflow for demultiple and PZ summation for two component OBC data - A 2D case study
Riaz Alai, Shivaji Maitra · 2014
Summary Traditionally PZ summation has been done before any demultiple processes for Ocean Bottom Cable (OBC) - PP type of processing. However, every now and then this question does come up - “Would the PZ summation be more effective if the P (pressure) and Z (particle velocity) components went through the demultiple process first? ”. Through this case study we have attempted to understand this question better and see if we can improve the PP image by first removing the multiples and then following this with PZ summation. The test is executed on two 2D lines acquired in an area which presents a case of large amounts of multiple generated from shallow gas bodies. Both, demultiple and PZ summation processes have been optimized separately for each case (i.e. demultiple before and after deghosting). We will show from our examples that the PZ summation done on demultiple data gives a better PZ summation result and also ends up producing cleaner gathers and stacks as compared to performing demultiple after PZ summation. This leads us to establish a new paradigm for an alternative approach to processing PP data, especially in multiple rich environments.