Acquiring The World’s Largest Onshore Nodal Seismic Survey: Field Operations And Processing Perspectives On High Density Seismic Acquisition

This paper helps operators and seismic contractors in the Middle East understand the pros and cons of high volume, high-density single-sensor land seismic acquisition with nodes, based on real-world experiences. We believe this survey represents the largest onshore nodal survey ever completed, and so the lessons learned are of great interest to all seismic practitioners in the region.

The paper will present and analyse operational information and workflows from the project including: crew size, composition, logistics and HSSE; source and receiver productivity; survey and seismic data QC; and data transcription, delivery and processing. Technical challenges, such as deployment and acquisition in different terrain and conditions will be discussed and compared to experiences operating cabled systems of a similar size in such environments. Initial processing results will be presented, including decimation studies to assess the effect of receiver density on processing products.

Use of low-cost, lightweight, nodes has enabled faster, safer and denser acquisition when compared to cabled operations, even with a significantly smaller receiver crew size operating a much smaller vehicle feet. The field efficiency and resulting productivity achieved with nodes has reduced operational costs and accelerated project turnaround time, whilst simultaneously delivering improved spatial sampling and image quality. The sampling of this high-density survey meant that the unaliased wavefield could easily be recovered which expedited and improved key processing steps such as the application of noise attenuation. Spatial coverage of the survey area was also improved through the use of lightweight hand-portable nodes, as receivers could be easily deployed in challenging environments such as sabkha. QC and export of the large volume of seismic data presents some challenges, which are addressable using fit-for-purpose nodal data QC software and high capacity, high throughput, export media.