An Integrated Approach to Improve Time-Lapse Seismic Interpretation

Time-lapse (4D) seismic is a modern technology for monitoring production-induced changes in and around hydrocarbon reservoirs. Perhaps the most important challenges related to this technology are to perform quantitative time-lapse and to interpret time-lapse effects in thin layers. This book presents an integrated study of saturation and pressure effects on elastic properties. A workflow is developed to test the validity of Gassmann fluid substitution in real geological environments and it is applied on a turbidite reservoir from the Campos Basin, offshore Brazil. The magnitude of pressure effects on compressional-wave velocities is investigated by using two different approaches: laboratory and well measurements. This book also shows a novel methodology to assess rock properties that result from centimeter scale depositional layering by using X-ray computed tomography images along with laboratory velocity measurements and borehole logs. Finally, the equivalent properties of a heterogeneous sandstone reservoir are investigated for modeling time-lapse effects. The combined seismic response of thin layers of sandstones and shales was computed for depletion and injection scenarios.