When two or more seismic vessels operate simultaneously in the same geographic region and the acoustic energy from the source(s) of one vessel is recorded by receivers of the other vessel(s), Seismic Interference (SI) occurs. There are many reasons for the increase in density of marine seismic survey activity in various regions of the world, including but not limited to seasonal weather patterns, environmental restrictions, and lease activity. Additionally, the need for timely data acquisition for acreage evaluation can result in several seismic vessels concurrently acquiring data in the same general area.
In these cases, “time sharing” is required or encouraged. Within some jurisdictions in the world, active seismic sources are required to maintain a prescribed (by regulatory permit) distance from other active seismic sources. Whether it is to reduce the concern of recorded noise interference or to ensure compliance with a prescribed distance between active seismic sources, time sharing is a procedure by which the time available for acquiring or recording data is divided equally or shared among all the vessels involved in acquisition activities within that given area. Time sharing guidelines ensure an equitable solution is achieved for all vessels involved.
The IAGC has established time sharing best practices to provide guidance to the geophysical industry for efficiently and effectively engaging in time sharing when marine seismic crews are in close proximity of each other and are faced with potential seismic interference, environmental restrictions, adverse weather, permit restrictions, or other similar obstacles that may impede simultaneous operations.