Reliability analysis in dynamic systems: Implications for positioning marine seismic networks

Abstract

Real‐time integrated monitoring of reliability (the impact of undetected biases in positioning observations on the position of geophysical elements) during marine seismic surveys is essential to ensure there is no significant loss in the resolution of the processed seismic image. The B-method is currently the most rigorous testing procedure for bias identification. It has been used extensively in geodetic networks, but to date it has found very little application within a dynamic environment. Here the method is expanded for use in dynamic systems—especially in marine seismic positioning networks such as those represented by a multisource, multistreamer, multivessel acquisition system. With this approach, we have found completely rigorous reliability estimates based on an integrated navigation method. We conclude that although the reliability of a system is in general a consequence of the redundancy, its geometry, and the stochastic model of the observations, these factors affect internal and external reliability in rather different ways. A key contribution is the demonstration that simple, easily understandable, and explainable statistics can be used to give a more complete description of quality than that obtained from precision measures alone. Assessing precision alone may give a false sense of security regarding the quality of the location of a seismic spread. The exploration and production industry is now making increasing use of old and new marine streamer 3-D surveys as part of 4-D time lapse reservoir monitoring projects. A more rigorous approach to positioning data quality, such as the method described in this paper, may play a material role in the avoidance of interpretable artifacts in these projects.