Polyacrylamide (PAM) is not only used as efficient flocculants, but also used as an excellent thickener because of its high viscosity of aqueous solution. Polyacrylamide (PAM) can be used as additives for various purposes in oil production, such as drilling fluid, fracturing fluid and polymer flooding to improve oil recovery (EOR) because of its properties in thickening, flocculation and rheological properties. In petroleum exploitation, how to design and select its composition and structure, such as molecular morphology, molecular weight, ionic charge, and correct dosing technology is critical to specific application.
When polyacrylamide (PAM) is used as drilling fluid additive, polyacrylamide (PAM) is adsorbed on the surface of metal or clay particles to form liquid film, which changes from solid surface friction to liquid friction, thus lubricating bit and drilling tool, reducing friction coefficient of mud cake and reducing downhole accidents. The suspensibility of polyacrylamide (PAM) in drilling fluids is of great significance in oil and gas production and other industries. Suspendability refers to the resistance action of suspended ions when they move relative to the medium under the action of applied force field.
Polyacrylamide (PAM) is a high molecular chain polymer, which could wrap debris and make it difficult to disperse the debris into hydraulic drilling fluid. The debris can be separated from the mud by vibrating screen to remove harmful solid phase in the mud. Polyacrylamide also has a good friction reduction effect, can significantly reduce the friction between rotating drill pipe and borehole wall, and the friction between solid particles and solid particles in the mud, so drilling torque and circulating pump pressure are reduced.
When used in water plugging, because of the heterogeneity of formation, water immersion often occurs and water plugging is needed. The essence of water plugging is to change the seepage state of water in formation, so as to reduce water production, maintain formation energy and improve the ultimate recovery of oilfield. Polyacrylamide chemical water shutoff agent has the selectivity of permeability to oil and water, the permeability of oil can be reduced by more than 10%, and the permeability of water can be reduced by more than 90%. Selective water plugging is a characteristic that other water plugging agents do not have. Usually, the appropriate molecular weight of polyacrylamide is selected based on specific field conditions.