Partially hydrolyzed polyacrylamide (PHPA) is a polymer used for encapsulation of drill solids in the oil and gas. The PHPA has a high molecular weight (3000000-15000000 long chain) whose polyacrylamide polyacrylate 70/30 regarding a large giving the product a high activity clays Encapsulating to minimize hydration inhibition provides clays through fixing the anionic group of the molecules in the cation positions of the scrap generated, is anionic (negatively charged).

For the concentration of PHPA in the fluid, first be precipitated acrylamide molecule as a complex of tin. Based on their design, are water-based muds with mechanical filtration control for inhibiting hydration of clays, and have elasticity in terms of dispersion generally are known as sludge of low solids content.

Drilling mud is a fluid of appropriate physical and chemical characteristics, which can be air or gas, water, oil and water and oil combinations with different solids. It should not be toxic, corrosive or flammable, but inert to contaminants. The partially hydrolyzed PHPA is a polymer of high molecular weight anionic synthetic that is designed to inhibit clays to hydrate prone, leading to instability of the hole. The excellent condition of the hole experienced with the PHPA mud can be determined from a series of tests to confirm the quality thereof and in the case of water-gel and lignosulfonate mud, the polyacrylate is subjected to a study of the which include the determination of density, rheological properties, condition alkalinity or basicity.

Partially hydrolyzed polyacrylamide (PHPA) is a copolymer, substance formed when two or more substances are polymerized simultaneously, resulting in a product that is not a mixture of individual polymers, but a complex which has different properties from each polymer by separated. The PHPA case we refer to a polymer of high molecular weight whose main function is likely to inhibit shale hydration. The primary mechanism of inhibition is the polymeric encapsulation of the clay or shale perforated by attraction and anionic / cationic adhesion (oppositely charged). The resulting effective encapsulation prevents hydration of the hole and cuts. This polymer layer also protects the cuts to be made into thinner before or during the process of being separated from the solid mud system. The anionic high molecular weight polymers act as flocculants in low concentrations by binding many particles of clay. When concentrations are increased, the solids may be fully encapsulated, and the long chain polymer can act as deflocculant to prevent clays interact directly with each other.

Furthermore, the high molecular weight partially hydrolyzed polyacrylamide serving as viscosifier and encapsulant, and low molecular weight polyacrylate which acts as a thinner or flocculant. This polymer works best in water. It is stable at a temperature of 300°F. It is sensitive to PH and loses its effectiveness when the alkalinity is increased. It works well when you have a PH between 8.5 and 9.5; Calcium concentration less than 100 ppm. These polymers are highly thixotropic shear thinning properties. Polyacrylamide is also used as viscosifier casualties.