Partially Hydrolyzed Polyacrylamide (PHPA)
Definition - What does Partially Hydrolyzed Polyacrylamide (PHPA) mean?
Partially hydrolyzed polyacrylamide (PHPA) is a widely used polymer in the oil and gas industry due to its lesser cost and good water solubility.
PHPA is used as a functional additive in water-based drilling fluids.
The PHPA mud system stabilizes shale formations and influences cuttings and wellbore stability. PHPA can be used in mud systems varying from low solids to weighted muds systems utilizing fresh or saltwater.
Trenchlesspedia explains Partially Hydrolyzed Polyacrylamide (PHPA)
PHPA is a white granular powder, anionic in nature having a specific gravity of 1.25 to 1.40 and a bulk density of 40 to 46 lb/ft3. PHPA influences cuttings and wellbore stability and enhances solids removal by flocculation. It also works when used in higher concentrations in salt muds such as KCl- or NaCl.
For shale-control, PHPA can supposedly seal microfractures, coat shale surfaces with a film that retards dispersion and disintegration.
The viscosifying effect of the dissolved high molecular weight polyacrylamide polymer controls the rheological behavior of the PHPA mud.