It is a co-polymer of anionic character and high molecular weight. It is a water soluble polymer which is primarily used as a highly efficient fluid loss reducer, viscosifier and protective colloid for shales and cutting in fresh water, calcium, sodium brines and KCL mud systems. It is compatible with most of the drilling fluid products, biopolymers, PAC, CMC etc. It maintains hole stability by preventing shale swelling and erosion.

It maintains viscosity in solid free drilling fluid. As a bentonite extender in low solids non-dispersed mud, it can be used along with small addition of bentonite to suspend weight material.
COMMON NAME - PARTIALLY HYDRAULISED POLY ACRYLAMIDE (PHPA)