Polyacrylamide used in oil field flooding is dissolved in water to form a high viscosity fluid, which reduces the fluidity (fluidity) of injected water, reduces the water-oil fluidity ratio, and inhibits water migration (rapid breakthrough of injected water along the high permeability layer), so that the displacement fluid can advance evenly and expand the spread volume. The high molecular weight polymer forms physical blockage through adsorption and trapping in the pore throat of the high permeability layer, forcing the subsequent injection water to switch to the low permeability layer, improving the reservoir heterogeneity and improving the microscopic oil washing efficiency. Some modified polymers (such as surfactant-polymer composite system) can reduce the oil-water interface tension, assist in stripping oil film, and improve oil recovery.

Features and advantages

Significant recovery: compared with water flooding, the recovery rate can be increased by 8%-15%, and the oil increase effect of single well is significant.

Mature technology: the technology has been applied in Daqing, Shengli and other oilfields on a large scale, and the supporting equipment is perfect.

Environmentally friendly: polymers are biodegradable (some modified products need to be evaluated) and easier to handle than chemical flooding (such as surfactants).

Specification

The Project	Indicators of
Exterior appearance	White granular powder
Solid content (%)	≥88
Molecular weight	12 to 21 million
Residual monomer content (%)	0.1 or less
Dissolution time (min)	≤90