A Well-to-seismic Interpretation of Interwell Connectivity Using Well Behaviour Data and 4D Seismic Surveys

A technique is proposed to quantitatively measure inter-well connectivity by correlating multiple 4D seismic monitors to historical well production data. We make use of multiple 4D seismic surveys shot over the same reservoir to generate an array of 4D seismic differences. Then a causative relationship is defined between 4D seismic signals and changes of reservoir fluid volumes caused by injection and production activities. This allows us to correlate seismic data directly to well data to generate a “well2seis” volume. It is found that the distribution of the “well2seis” correlation attributes reveals key reservoir connectivity features, such as the seal of faults, inter-reservoir shale and fluid flow pathways between wells, and can therefore enhance our interpretation on inter-well connectivity. Application of our proposed technique proves that the well2seis attribute agrees with geological interpretations better than conventional well connectivity factors based on engineering data only. Additionally, combining with a conventional inter-well study method, this multiple 4D seismic method is found to support the conventional inter-well approaches and can provide more robust and detailed interpretation.