Upcoming zero discharge regulations, high rig time cost, and low oil prices are motivating the industry to look for faster, more effective displacement that reduce the volume of fluid to dispose and decrease circulation time.
A field study conducted in South East Asia showed that more effective displacement can be achieved by adding to the circulating fluid a polymeric flocculant instead of the commonly used surfactants.
A laboratory investigation was undertaken to understand the fundamental mechanism governing well bore clean-up. Its conclusions are as follows:
under the highly turbulent flow conditions reigning during displacement operations, saltwater cleans metallic surfaces as well as surfactant solutions;
polymeric flocculants form larger and stronger aggregates of solids than surfactants which can withstand better the stresses associated with turbulent flow. This improves the sweeping efficiency of the circulating fluid by increasing fluid drag force on the solids.