Scientifics have proposed different technologies such as lubricants, vibratory tools, tractors and taper designs to extend coiled tubing reach. Among these technologies, Lubricant is the simplest solution for well intervention operations.
Several modeling and laboratory studies have been reported in field of lubricants and coiled tubing friction, but performance of lubricants has not been validated at downhole conditions. In this project, we will investigate available polymers as lubricant and we will establish experimental set up to study friction reduction between coiled tubing and well casing by lubricants.
We have reviewed various papers and patents in field of mechanical metal-on-matal friction and hydraulic drag/friction reducer for coiled tubing operations. We have found polymers or other chemical additives should be mixed with downhole fluids to reduce mechanical friction between coiled tubing and casing or reduce hydraulic friction. In order to explore the efficiency of polymers as lubricant or friction reducer, we need to establish experimental set up. Now we are considering following three options to explore and validate use of polymers:
- Experimental set up to investigate mechanical metal-on-metal friction
- Experimental set up to investigate mechanical metal-on-metal friction and hydraulic drag/friction reducer
- Experimental set up to investigate relation between mechanical friction, drag and buckling
Friction tester is the main instrument that we need to start the experimental study of this project. Among different friction testers, linear friction tester can measure coefficient of friction close to downhole condition. The most important factors that should be considered, in the lab testing procedure, are temperature, fluid type and composition of downhole fluid, and contact surface type and roughness of surfaces.