Enhancing dynamic interpretation at the Valhall Field by correlating well activity to 4D seismic signatures

Abstract

Sequences of 4D seismic changes extracted over different time intervals from multiply repeated seismic surveys are correlated with the identical time sequences of cumulative fluid volumes produced from or injected into wells. Maps of these cross-correlations have previously been shown to produce a localized signal in the connected neighbourhood of individual wells. The technique is applied to the frequently repeated seismic surveys from the life of field seismic project in the Valhall Field, for which the 4D seismic signature is dominated by compaction-assisted pressure depletion. For these data, both acoustic impedance and time-shift attributes are found to have a remarkably consistent correlation with the well activity from selected groups of wells. Furthermore, maps of these results have sufficient fine scale detail to resolve interfering seismic responses generated by closely spaced wells and discrete zones of gas breakout along long horizontal producers. We conclude that uniting well data and 4D seismic data using our proposed method provides a new attribute for dynamic interpretation of the producing reservoir.