PRM Techniques can Significantly Increase Time Lapse Sensitivity

tional 4D for mitigating the causes of non-repeatability and therefore leads to better 4D sensitivity: • Permanent receivers (and sometimes permanent sources) are much more stable than re-deployable receivers or moving sources. • The positioning is more than 50% solved by PRM techniques. • In the design phase, it is relatively easy to select parameters to optimize this mitigation (receiver depth and source grid density of the base survey) and to add devices to help this mitigation (echo sounder to monitor the water column and extra seismic sensors to monitor noise sources).