Polymer Flooding - Designing of a Pilot Test for Unusually High Salinity and Hardness Reservoir

Reservoir conformance problems render uneven the flow of the injected water making waterflooding inefficient due to poor mobility control. This paper describes a systematic approach taken for the designing of a polymer flooding pilot test for a reservoir with challenging characteristics such as unusually high salinity and hardness that complicate the selection of the candidate polymer. This work includes a description of the characterization of a pre-selected candidate polymer, its rheological evaluation, its adsorption performance onto porous media, and its mechanical stability. Together with rheological properties, emphasis is given to the evaluation of flow performance of the polymer onto porous media at reservoir conditions. The experimental results indicate that the selected polymer (acrylamide/ATBS/acrylic acid ter-polymer) shows proper performance especially in terms of tolerance to reservoir salinity, hardness and high temperature. Numerical simulation studies demonstrate that polymer flooding at the selected zone could render a favourable incremental oil recovery (16%) over waterflooding.