Polymer Flooding Process to Increase Recovery Factor

This paper describes a methodology, developed at the Instituto Colombiano del Petróleo (Colombian Petroleum Institute) of Ecopetrol, for the theoretical evaluation, project design (screening, geological and engineering analysis, experimental evaluation, numerical simulation and financial analysis), pilot implementation and surveillance of the polymer flooding process which is a commercial Enhanced Oil Recovery (EOR) technology. Its principal objective is to improve reservoir sweep efficiency in mature and recent waterfloods. The polymer flooding pilot test implemented in the south of Colombia by Ecopetrol includes two injector wells with irregular patterns. Polymer injection started in May 2015. At October 2016, cumulative polymer injection reached 1.5 million barrels distributed between both injectors at a polymer concentration range between 200-1500 ppm and injection rates between 2 000-3 200 BPD per pattern. Production initial response has been positive with a cumulative incremental that exceeds the 63 000 barrels of oil with reduction of water cuts of up to 10 %. Additionally, polymer production has not been detected in any of the offset producers of pilot injectors. The polymer flooding pilot test have allowed the assimilation of learned lessons, best practices for continual improvement in the operation of such processes, incremental oil production; water cut reduction and increases in the fluid levels for the first row of offset producers. Based on the pilot success, the feasibility of expanding this EOR method in this field is being evaluated.