Reconciliation of Time-Lapse Seismic Data with Production Data for Reservoir Management: A Gulf of Mexico Reservoir

Abstract

Abstract Integration of time-lapse seismic and production data provides an effective tool for reservoir management. However, extensive work is required to build a "common" earth model1,2 honoring both types of data. This typically leads to longer turnaround times for time-lapse seismic projects. This paper demonstrates a method to shorten this time by reconciling production data with time-lapse seismic data in the data domain rather than in the earth model domain. The results from this method demonstrate that this quick evaluation can reveal whether or not the observed seismic differences represent reservoir changes associated with production, and can provide a basis for a more extensive model based evaluation. This method was applied to a gas reservoir in the Gulf of Mexico where preliminary rock physics modeling showed that water replacement would lead to more than 10% impedance change for approximately 30% of gas saturation change. The saturation-amplitude relation used to threshold the seismic difference volume was calibrated at the well or predefined locations. The threshold was optimized through solving the material balance relation obtained from production data with the time-lapse seismic data, thus making it more likely that the seismic differences are representative of saturation changes in the reservoir. This work: (1) provides a new procedure for gas reservoir time-lapse analysis under certain geological and production conditions; and (2) demonstrates a new first order method to reconcile time-lapse seismic data and production data without employing time consuming reservoir characterization and flow simulations. This approach greatly reduces the turnaround time involved in the use of time-lapse seismic information for reservoir management. Further, the result could lead to better subsequent model based analyses1,2.