Define the reservoir screening window
Polymer flooding uses water-soluble polymer to increase injected-water viscosity and improve the mobility relationship with reservoir fluids. State formation temperature, permeability, oil viscosity, injection-water composition and target viscosity before requesting a grade.
A generic molecular-weight number cannot establish fit. Brine ions, dissolved oxygen, shear, rock interaction and biological control can alter the viscosity delivered at the well.
Measure viscosity in the actual water
Prepare candidates with representative injection water and the planned water-treatment sequence. Measure viscosity at specified concentration, temperature, shear rate and aging time rather than comparing supplier values produced under unrelated conditions.
Record clarity, incomplete dissolution and precipitate as well as viscosity. A high initial value is not useful if the solution cannot be filtered, pumped or injected consistently.
Challenge salinity and hardness
Divalent ions can reduce the effective hydrodynamic size and viscosity of hydrolyzed polyacrylamide. Screen normal and credible high-salinity or hardness conditions, including changes caused by source-water blending.
Use compatibility bottles, viscosity curves and filtration observations to define the water window demonstrated by the candidate. Do not infer high-salinity suitability from a product name alone.
Simulate mechanical shear
High-molecular-weight chains may lose viscosity through pumps, valves, mixers and narrow restrictions. Apply a repeatable shear protocol and compare retained viscosity in the same brine and temperature condition.
Map the surface route from make-down to injection. Equipment changes after a laboratory screen can change the polymer arriving at the formation.
Check filtration and injectivity risk
Undissolved particles, gels, contaminants and incompatible water can raise filter ratio or contribute to plugging. Use the operator's filtration and core or injectivity criteria during qualification.
A candidate should meet viscosity and cleanliness requirements together. Increasing concentration to replace lost viscosity may worsen filtration or economics.
Link the approved sample to supply
Record sample code, lot, hydrolysis or ionic profile, solution method and test water. Request the current COA, SDS, packaging, storage and production traceability for the proposed commercial code.
Approve only the tested operating window. Reservoir engineering, injection design and local chemical requirements remain the operator's responsibility.