Integration of production and time-lapse seismic data

Methods for application of time lapse seismic data to reservoir management range from purely qualitative evaluation, to its use as a constraint in rigorous numerical dynamic model optimization. The advantage of numerical optimization over qualitative analysis is that the former provides a quantitative reservoir model much needed for practical reservoir management applications. However, the large gap existing between these qualitative and quantitative methods not only inhibits wider use of time lapse seismic data as a reservoir monitoring tool, but also represents the unnecessary delay of integration between seismic and production data until very advanced stages of reservoir model building. Recent work by Huang et al (1999a) lead to a method for early integration of time-lapse seismic and production data in a Gulf of Mexico gas field 4D study. Such early integration helps to reduce ambiguity in time-lapse seismic data processing and provides useful semi-quantitative results which may be used for some engineering applications. The numerical optimization process data benefits from this preliminary step through improved initial estimate and more efficient convergence. The overall results of this two stage integration approach are; useful intermediate products, improved turn-around time, and increased reliability in model based time lapse analysis.