POLYCAP® is a shale inhibitor/ solids encapsulating polymer for water-based drilling fluids. It is a water soluble product of polyacrylamide and sodium acrylate copolymerization. POLYCAP® is an anionic polymer meaning it is attracted to the clays cationic surfaces and encapsulates them with the polymeric film. It is used in freshwater, seawater, NCl and KCl mud systems.
Description
POLYCAP® is a shale inhibitor/ solids encapsulating polymer for water-based drilling fluids. It is a water soluble product of polyacrylamide and sodium acrylate copolymerization. POLYCAP® is an anionic polymer meaning it is attracted to the clays cationic surfaces and encapsulates them with the polymeric film. It is used in freshwater, seawater, NCl and KCl mud systems.
POLYCAP® molecular weight ranges up to 20 million. Due to the carbon-carbon linkage, the polymer has exceptional thermal stability and is resistant to bacteria. The polymer attaches to cutting and clays on the wellbore and blocks the hydration and dispersion of the clay particles. Because of its high molecular weight it combines with several sites along the wellbore and restricts water from entering the sensitive formation.
Applications/Functions
- Coats the wellbore wall with the polymeric film and provides superior wellbore stability
- Helps preserve cuttings integrity, allows easier cuttings removal at the surface
- Increases water phase viscosity thus limiting the filtrate invasion into the fissures and fractures within a shale
- Forms a thin and firm filter cake
- Improves mud lubricity
Advantages
- High thermal stability (up to 150C)
- Effective in a salt environment
Recommended treatment
1-2.5 ppb (2.8-7 kg/m3). POLYCAP® treated mud can be slightly flocculated and the polymer unsheared for the first circulation or two. It is recommended to keep the MBT value lower than 20 ppb (56 kg/m3). It is recommended to keep pH values lower than 10.5 and total hardness – lower than 500 mg/l. Please refer to the product brochure for more information.
Typical properties
White free flowing powder
Handling
Please refer to the MSDS for specific instructions
Packaging
POLYCAP® encapsulating agent is packaged in 50lbs (22,7 kg) bags
