From the Middle East and Central Asia to oilfields in western China, the proportion of high-salinity produced water continues to rise. 

A high-salinity environment directly interferes with the molecular chain extension of flocculants. 

Under high TDS conditions, conventional polyacrylamide molecules curl up, reducing flocculation efficiency — manifested as fine flocs, slow settling, and poor sludge dewatering performance.

Many field operators report that the same PAM product with identical molecular weight and ionicity works well in freshwater conditions, 

but when switched to high-salinity produced water, the dosage must be increased significantly while the treatment result still falls short of expectations.

Industry practice highlights several key selection criteria:

1. In high-salinity systems, prioritize evaluating the salt-tolerant backbone structure of the chemical rather than relying solely on molecular weight.

2. The dosing sequence and ratio of inorganic coagulants (such as PAC) and PAM must be reconfirmed through jar tests — freshwater experience cannot be directly applied.

3. In the sludge dewatering stage, high salinity alters the colloidal charge of sludge, so the ionicity of cationic PAM also needs to be re-evaluated.

As global requirements for produced water reuse and reinjection continue to tighten, market demand for salt-tolerant water treatment chemicals is growing steadily.