Water-based Enhanced Oil Recovery (EOR) technologies such as Low Salinity Flooding (LSF), Chemical EOR (CEOR), and steam-flooding have been growing in popularity over the years, and are generating new opportunities for the water treatment sector as a result. Water treatment technologies have the unique capability to address equipment and system requirements which are characteristic of EOR projects. However, these technologies typically have little to no history of application in the upstream oil and gas industry. This limited level of experience may impact EOR project budgets and schedules, particularly in offshore applications where weight and footprint availability are of critical value.
In Southeast Asia, two offshore projects are investigating the use of customized water to maximize oil recovery in CEOR applications. In the first project, two CEOR programs consisting of vastly different water quality cocktails are under consideration, one of which incorporates produced water into its water source. In the second project, injection water quality with an ultra-low hardness level is desired, in order to prevent potential precipitation in the reservoir. In both cases, water treatment infrastructure must be capable not only of producing the intended injection water quality, but it must do so consistently in response to potential changes in the quality of the source water used.
This paper describes the results of pilot testing of two typical water treatment technologies, Reverse Osmosis (RO) and unique nanofiltration membranes, to produce a variety of injection water chemistries for CEOR and LSF applications. These applications include 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.