Technical Library

Deconvolution of upgoing and downgoing wavefields: A data example from the NOAKA OBNexperiment

Ocean bottom node surveys are popular tools for both seismic exploration and monitoring due to the possibility for superior imaging and velocity model building compared to towed streamer surveys. In addition, the size of ocean bottom experiments has been increasing. This increase in frequency and survey size requires efficient processing solutions for attenuating free surface effects such as ghosts and multiples both in terms of usability and computing requirements. Traditionally, these processing steps were implemented by up-down wavefield separation to target the receiver-side effects, followed by separate source-side deghosting and demultiple. We have recently adopted the combination of up-down wavefield separation with up/down deconvolution or downgoing wavefield deconvolution as an alternative due to the simplicity of the process and the high quality of the results.

In this paper, we review up/down deconvolution as a demultiple and deghosting method for the upgoing wavefield and describe downgoing wavefield deconvolution as a similar process for the downgoing wavefield. Moreover, we perform both up/down deconvolution and downgoing wavefield deconvolution in a single processing flow. This combination simplifies the processing sequence, decreases the human effort, and reduces processing turnaround compared to our legacy solution. While being more userfriendly, our new solution has conserved the advantages of the legacy solution and delivers complimentary images using the up- and downgoing wavefields. Crucially for regions with a shallow seafloor, the downgoing wavefield permits superior imaging of the shallow subsurface.