Solving the Seismic Detectability Issue of Emulsion Formation for Chemical EOR

Using geophysical methods to monitor chemical floods is a significant challenge due to the lack of impedance contrast between the unswept oil zone and chemically flooded zone. Further challenges arise when the elastic properties of sea water and formation water are similar and the chemical may thermally degrade and be adsorped to the rock due to high reservoir temperature. This study focuses on the possibility of detecting Chemical EOR (CEOR) from a time lapse perspective after three (3) years of production by exploiting the significant difference in elastic property values of an emulsion formation between the injected chemical and oil. Adjusting the parameters in the Rock Physics Model (RPM) and the seismic modelling according to the CEOR condition are the key factors in the simulation-to-seismic analysis. Next, the calibrated RPM results are used to transform the flow simulation model into seismic scale cells to observe the CEOR effect before and after suggesting residual oil of 0.4 and below could be detected in a synthetic model based on the volume of emulsions produced during the Alkaline-Surfactant (A-S) injection phase.