Bruce L. Knight

Reservoir Stability of Polymer Solutions

Dissolved oxygen is harmful to the stability of polyacrylamide solutions, specifically Dow Pusher 700. It is believed that oxygen serves as an initiator for a free-radical reaction between oxygen-derived radicals and traces of reducing agents also present in solution. Sodium hydrosulfite has proven effective in oxygen control of polyacrylamides but must be used very carefully to prevent degradation of polymer solutions. Formaldehyde is generally recommended for field use because it is less expensive, easier to handle, continues to scavenge oxygen in the line after mixing, and performs a dual purpose, also serving as a biocide. Neither temperatures up to 140/sup 0/F nor water salinity affect polymer solution stability.

Injection Well Logging Using Viscous EOR Fluids

A new tool has been developed that overcomes problems associated with logging injection wells in the presence of viscous fluids. The tool was evaluated in the laboratory and the field in water and polymer injection wells. Results indicate that the tool provides better information than conventional equipment. Special attention to log interpretation is required in zones where the flow pattern changes from turbulent to transition flow. A method is suggested to improve log interpretation that considers changes in flow regime.