Figure 1 – P-Cable Ultrahigh Resolution 3D (UHR3D) Seismic System Diagram. The number of streamer cables is generally between 12 and 24, with 3.125 to 12.5-meter crossline separation between cables. The individual streamers are connected to a cross-cable (known as the “P” or perpendicular cable) and typical cable lengths range from 50 to 100 meters with a receiver group interval of 3.125 or 6.25 meters. This very compact receiver array allows seismic vessels to operate in close proximity to the shoreline or offshore infrastructure.
Figure 2 – Comparison of conventional streamer 3D (top) with P-Cable UHR3D (bottom) in the Barents Sea. The conventional data has been reprocessed at 2 msec sampling, and both datasets are processed through pre-stack time migration processing flow using broadband techniques for maximum resolution. Data courtesy OMV.
Figure 3 – Time slice comparison of conventional streamer data (left) and P-Cable data (right) through the faulted zone in the Cretaceous section underneath the regional unconformity. The denser inline and crossline sampling of the P-Cable data, in combination with the finer temporal sampling, accounts for the ability of P-Cable to image the complex polygonal fault system with such incredible detail.
Figure 4 – Time lapse images of the Sleipner CO2 plume. North-South inline through the plume (top) and plan view of total reflection amplitude in the plume (bottom). Figure from Chadwick, A. and Williams, G., et.al., Quantitative analysis of time-lapse seismic monitoring data at the Sleipner CO2 storage operation, The Leading Edge, February 2010, pp 170-177.
Figure 5 – P-Cable time lapse seismic monitoring example from offshore Louisiana. The pre-stack depth migrated images in the upper left are the 2016 baseline and 2017 monitor surveys with the dark blue line indicating the location of the water inject well. Despite the relatively modest change in reflection amplitude as water replaces oil, the P-Cable data is able to reliably extract the 4D signal and delineate the relative movement of water and oil.
Figure 6 – Shallow subsurface imaging comparison of conventional OBN data (left) and P-Cable UHR3D baseline survey data (right) from the offshore Louisiana field shown in Figure 4. The P-Cable dataset shows a dramatic improvement in the imaging of small scale faults, and is even able to image the imprint of three plugged and abandoned exploration wells.
Figure 7 – Comparison of conventional high-resolution seismic data (left) and P-Cable Ultrahigh Resolution data (right). In addition to the overall enhancement in subsurface resolution, note in particular clearly delineated the gas chimney on the right-hand side of the P-Cable section is. Both the wipeout zone associated with gas leakage along the chimney, and free gas accumulations (“bright spots”) within the chimney are clearly imaged.
Figure 9 – A 3D perspective view of P-Cable seismic data offshore California showing neural network fault and chimney attributes. Fault attributes (black) and chimney attributes (color) are show on top of seismic amplitudes along a time slice at 174 milliseconds, illustrating the relationship between faults and gas chimneys. Note on the crossline vertical section the termination of the dense zone of high-chimney probabilities below the shallow, abruptly ending high-amplitude reflectors interpreted as bright spots. Kluesner, J. W., and D. S. Brothers, 2016, Seismic attribute detection of faults and fluid pathways within an active strike-slip shear zone: New insights from high-resolution 3D P-Cable™ seismic data along the Hosgri Fault, offshore California: Interpretation, 4, no. 1, SB131–SB148, http://dx.doi.org/10.1190/INT-2015-0143.1