The time-lapse, or 4D, seismic method involves acquisition, processing, and interpretation of repeated seismic surveys over a producing hydrocarbon field. The objective is to determine the changes occurring in the reservoir as a result of hydrocarbon production or injection of water or gas into the reservoir by comparing the repeated datasets. A typical final processing product is a time-lapse difference dataset (i.e., the seismic data from Survey 1 is subtracted from the data from Survey 2). The difference should be close to zero, except where reservoir changes have occurred.
WesternGeco differentiated technologies offer a complete 4D solution from feasibility studies to inversion and history matching, Q-Marine Dynamic Spread Control and in-depth experience.
Comprising a two-step analysis: 4D feasibility study, and survey evaluation and design.
WesternGeco calibrated technology with its highly accurate positioning and steerable streamers enables a clearer 4D image for more accurate interpretation.
A carefully designed time-lapse seismic processing flow can help compensate for variations in acquisition.
Integrating 4D seismic into the reservoir model to monitor changes in the reservoir properties.