Engineering of injection water chemistry has been recently found to be one potential cost-effective method to improve oil recovery in carbonate reservoirs. These engineered waterflooding processes solely depend on tuning the salinity and ionic composition of injection water without the need for any external costly additives or major modifications in the injection and producing facilities. In this talk, we provide the desired salinity and water composition guidelines for engineered waterflooding processes besides describing several practical ways to generate optimal engineered injection water from both high salinity water and produced water for field applications.<br/><br/>A suite of multiscale experimental data gathered at both fluid-fluid and rock-fluid interfaces using state-of-the-art interfacial techniques and advanced microscopy-imaging techniques are presented. These results demonstrate that atomic to molecular scale interactions occurring at both the interfaces play a major role to dictate oil release, connectivity, and mobilization in engineered waterflooding. The salinity threshold ranging from 5,000 to 7,000 ppm TDS together with adequate concentrations of three key ions such as calcium, magnesium, and sulfates have been identified as the optimal tailored injection water. The two practical solutions were proposed to generate the optimal engineered water from the abundantly available natural high salinity water. These include: reverse osmosis (RO) or a combination of nanofiltration (NF) - reverse osmosis (RO) based water treatment processes.<br/><br/>The importance for circular water economy to conserve natural water resources has been very well realized in oil industry. If produced water is treated and reinjected into reservoir as engineered water for improved oil recovery, it can become a real game changer to promote circular economy. We also discuss about emerging produced water desalination technologies such as dynamic vapor recovery that can provide engineered water from high salinity produced water with minimal pretreatment. These produced water desalination technologies are also capable of providing zero liquid discharge (ZLD) solutions. In a nutshell, the utilization of treated produced water in engineered waterflooding offers a win-win technological solution; a win for the environment by minimizing wastewater disposal and a win for circular economy due to the reinjection of produced water into the reservoir for sustainable oil recovery.

Injection water chemistry alteration and produced water recycle/reuse for sustainable oil recovery

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.