Christian Hubans

Quantitative 4D warping inversion

Born nearly thirty years ago, time lapse (4D) seismic monitoring has proven to monitor fluid movement and to distinguish between drained and undrained portions of a reservoir. Its ultimate aim is to quantitatively contribute to improving reservoir models, to the benefit of their predictive capability. Now, the benefits of time-lapse seismic for reservoir characterisation do not depend only on the quality of 4D acquisition and processing; they also greatly depend on the particular 4D inversion scheme used.

4D baseline acquisition feasibility study including optimization of 3D issues

Various issues can be solved by acquisition of a new baseline. Present example based on a feasibility study performed in Offshore Africa illustrates ways of improvements identified: Acquisition direction optimization in order to minimize coverage gap left below obstructions (4D issue). Acquisition navigation strategy optimization (steering for pre-plot) in order to improve data repetitivity (4D issue). Streamer length optimization in order to reduce uncertainty in depth positioning of development wells (3D issue). Bin size optimization in order to have a high density reference dataset (3D and 4D issue). Shot interval optimization to increase fold coverage and improve Signal/Noise. (3D and 4D issue). Source and streamer depth optimization to acquire frequency bandwidth adapted to the fields. Benefit from recent acquisition equipment, such as steering devices, solid streamers, recent positioning devices and broad band technologies (3D and 4D issues).