Preliminary study of nanofiltration for production of smart water from produced water

Abstract

Production of smart water from produced water is the focus of the thesis. Smart water performance is regulated by the concentration of ions such as Ca2+, Mg2+ and SO42-. Choosing produced water as the source for smart water is a wise step as it reduces produced water discharge making it suitable for pressure support in EOR. Experimental setup of the project consists of a nanofiltration (NF) membrane coupled with ion exchange for barium removal. NF membrane separation was designated to increase the concentration of Ca2+ and Mg2+ while ion exchange was used for barium removal in order to prevent BaSO4 scaling. These experiments were carried out using synthetic produced water sample from Tor Field. EM-NF-1812-50 and NANO-BW-4040 NF modules were used. Concentrate from NF was selected as the source of smart water. NF membrane separations were able to increase the concentrations of Ca2+ and Mg2+ by 24 – 85 %. EM-NF-1812-50 gave higher retention while NANO-BW-4040 was more preferable due to its ability in changing the pressure. Ion exchange removed 99 % of barium. According to the experiments, a combination of separation processes by NF and ion exchange is proposed as a potential solution to increase the quality of produced water as smart water.