Shell Oil Comapny

Shell Usa, Inc.

Paul Maarten Zwartjes

Albena Alexandrova Mateeva

Johan Cornelis Hornman

Receiver-consistent scalars of seismic receiver channels are used for time-lapse monitoring of a sub-surface earth formation. Signals are induced by seismic waves propagating through the earth formation adjacent to each respective seismic receiver channel. Each seismic receiver channel is acoustically coupled to the earth formation as present directly adjacent to the location of the seismic receiver channel in question. The base receiver-consistent scalars and the monitor receiver-consistent scalars of seismic receiver channels can be outputted to reveal changes in these receiver-consistent scalars. These changes can be used to delineate information about physical changes in the subsurface earth formation. The changes in the based receiver-consistent scalars and the monitor receiver-consistent scalars may be displayed visually.

Method of time-lapse monitoring using seismic waves

A seismic receiver array has a plurality of seismic receiver channels, each coupled to a local surrounding in an earth formation. A formation-material-dependent response of each seismic receiver channel is determined, and associated with an assumed depth for the corresponding seismic receiver channel. The formation-material-dependent responses as function of the assumed depth are compared to an independent depth log of at least one petrophysical parameter of the earth formation as a function of depth along the borehole. Based on the comparison, a set of lags between said assumed depth and depth in the independent depth log is determined, that provides the best correlation between the formation-material-dependent response and the independent depth log of the at least one petrophysical parameter of the earth formation. The assumed depth of each seismic receiver channel can thus be aligned with corresponding depths in the independent depth log.

Growing community of inventors

Rijswijk, Netherlands

Paul Maarten Zwartjes