Maximizing Oil Recovery - Developing and Piloting Offshore Facilities to Customize Water for CEOR and Low Salinity Injection

Abstract

The growing popularity of water-based enhanced oil recovery (EOR) technologies, such as low salinity injection (LSI), chemical EOR (CEOR), and steam-flooding, has created new opportunities for the water treatment industry as a function of the unique requirements of equipment and systems in EOR projects. In some cases, the needed technologies have little to no history of application in the upstream oil and gas industry, therefore impacting EOR project budgets and schedules. These issues become particularly acute in offshore applications that are generally limited by footprint and weight, thereby further reducing suitable water treatment options. Two offshore projects in Southeast Asia are pioneering the use of customized water to maximize oil recovery in CEOR applications. In one project, two vastly different water qualities are being developed which correlate to two CEOR cocktails under consideration. The water treatment infrastructure must be capable of providing either water quality and be responsive to water quality impacts associated with produced water injection facilities such that the blended injection water quality maintains consistency. In the other project, an ultra-low hardness level is desired in the injection water, to prevent potential precipitation in the reservoir. This paper describes the results of pilot testing of reverse osmosis and unique nanofiltration membranes to produce a variety of water chemistries for CEOR and LSI applications, including ultra-low hardness, high salinity; and low hardness, low salinity injection water. The testing confirms the ability of new water treatment technologies to solve challenging issues that arise in EOR applications, particularly those in offshore applications that must respond to varying needs of reservoirs and footprint/weight limitations.