Bubble Effects on Seismic Data caused by Seawater Temperature Variations.

Abstract

At the 76th EAGE Conference in June 2014, professor Martin Landrø proposed a new equation for the air gun bubble time period that includes the effect of varying sea water temperature. The work in this thesis has been to investigate the effects of varying sea water temperature and relate these effects to the new equation.Several synthetic experiments have been done with the purpose of detecting any significant effects originating from variations in the sea water temperatures that can be discovered on seismic sections. First, the new equation proposed has been compared against simulated experiments of source signatures in a numerical software. Then, synthetic 4D seismic has been generated with a simulated variation in the sea water temperature for the baseline survey and the monitor survey. In addition, corresponding 4D seismic sections have been simulated without variations in the sea water temperature.By comparing these data against each other, the 4D response resulting from variations in the sea water temperature could be identified. The synthetic experiment showed that variations in the seawater temperature can have a significant effect for 4D seismic.