Integration of 4D Seismic and Pressure Transient Analysis for Flood Front Estimation

Summary Time-Lapse (4D) seismic data is used in conjunction with Pressure Transient Analysis (PTA) to quantify the extent and shape of waterflood fronts in a deep-water Gulf of Mexico case study. The waterflood front positions are interpreted on 4D seismic amplitude difference maps and the flood front is modelled in analytical PTA. The asymmetric flood front is investigated in a numerical PTA model and parameter sensitivities for matching both the 4D seismic interpretation and the pressure falloffs tests are explored. The workflow allows for iterations in the interpretation of the 4D flood front as well as updates to the parameters used in the numerical PTA until a satisfactory model is created which matches both the 4D seismic data and the pressure falloffs used in PTA. Together, the joint iterative analysis helps to reduce uncertainty in the products delivered by the individual techniques, resulting in quantitative flood front positions that can be used in assisted history matching of reservoir flow simulations. The case study establishes the value of utilizing 4D seismic in an integrated workflow with PTA techniques for generating flood front constraints that aim to improve forecasting models and guide reservoir management decisions.