4D Seismic
4D seismic is now a well-established technique which is making a valuable contribution to the production and development of hydrocarbons around the world. As the technique has matured with the development of expertise and technology there has been an evolution in its use.
Originally the accuracy of the technique limited it to being a qualitative indicator of production effects. Even at this stage 4D seismic delivered tremendous value in terms of interpretation of internal reservoir structure and the identification of depleted and unswept zones.Advances in technology, especially 4D processing, have allowed us to produce more precise 4D seismic differences and transform these into the context of reservoir engineering. With proper calibration and petrophysically constrained inversion techniques we are now able to derive quantitative estimates of changes in reservoir properties such as fluid saturation and pressure.
This evolution in the role of 4D seismic from a qualitative tool to a powerful quantitative technique represents a significant step-change in the value of 4D. It also indicates a shift from a purely geophysical interpretation tool to a reservoir management tool, which can be used to assess remaining hydrocarbon volumes and optimize the recovery strategy.
