Untethered Downhole Viscosity Logging for EOR Polymer Fluid Degradation Monitoring

Enhanced Oil Recovery (EOR) operations based on polymer flooding can be severely impacted if the long-chained polymer molecules used to increase the viscosity of the injected fluid are degraded. This may occur either by mechanical or chemical means at any point of the injection process. Degradation leads to a reduced viscosity, ultimately reducing the effectiveness of the EOR operation. Monitoring the polymer viscosity would help reducing the risk of degradation, which could significantly impact oil recovery rates. Currently, there are no means to perform frequent checks for polymer degradation downhole during injection. We describe a small, untethered downhole tool with an onboard viscometer. The tool is simple and cost-effective, and it can be deployed routinely without need of a wireline logging crew. This instrument may be useful in detecting polymer degradation downhole.