Polyacrylamide is widely used in chemical, metallurgy, petroleum, geology, coal, early knowledge, textile, water treatment and other industrial sectors. Especially in the field of petroleum industry, polymer flooding technology plays an irreplaceable role in crude oil production as an important means to stabilize oil production. PAM is the most commonly used water-soluble polymer among polymers, and it is used as a drilling mud material with the following characteristics.
1. Water solubility of polyacrylamide
The application of pam flocculant is mostly in the form of an aqueous solution. Water solubility is the primary consideration in polyacrylamide applications. Hydrogen bonds form between the water molecules and the polar side groups of the polymer. Polyacrylamide can be dissolved in water in different percentages. Like other polymers, it can only dissolve in solvents with similar solubility parameters.
2. The viscosity of polyacrylamide increases
Polyacrylamide increases the viscosity of the water phase through its own viscosity; polyacrylamide interacts with the dispersed phase in water and other polymer compounds in water, and the effect is far greater than that caused by the viscosity of the polymer itself. Rheological properties Rheological properties refer to the flow deformation of substances under external and internal action. From the relationship between apparent viscosity and shear rate, under the condition of moderate shear rate, the water solubility of polyacrylamide tends to exhibit pseudoplasticity, that is, the apparent viscosity decreases with the increase of shear rate; From the perspective of the relationship between viscosity and time, another rheological property of polyacrylamide aqueous solution is high thixotropy, that is, the apparent viscosity decreases under the action of shear force, and gradually recover over time when the shear force is withdrawn.
3. Polyacrylamide dispersion
Like other polymers with high water solubility, polyacrylamide contains hydrophilic groups and also has a skeleton, so it has a certain surface activity, which can reduce the surface tension of water to a certain extent and help solids to be wetted by water. wet. In addition, due to the hydrophilicity of pam polymer flocculants, the water-colloid conjugate is adsorbed on the colloidal particles to form a shell, which can shield the flocculation caused by the electrolyte, keep the dispersion system stable, and protect the colloid.
4. Suspension performance of polyacrylamide
Suspension refers to the resistance of suspended ions when they move relative to the medium under the action of an external force field. The suspension of polyacrylamide itself or water-based fluids formed with other substances is of great significance in oil and gas exploration and other industries, such as drilling fluids with drill cuttings, completion fluid weighting agents, and fracturing fluids with proppants.
5. Polyacrylamide flocculation effect
The polar groups in polyacrylamide are adsorbed on the solid ionically bridged particles in water to form large aggregates. High molecular weight polyacrylamide is often used as a flocculant in the purification of sewage, and its rheology is of great significance when used in polymer systems lower than those of non-dispersed mud systems.
6. Polyacrylamide drag reduction
Drag reduction refers to the phenomenon that adding a small amount of chemical substances to the fluid greatly reduces the turbulent frictional resistance of the fluid passing through the solid surface. The drag reduction effect, drag reduction efficiency of polyacrylamide, and the effect of polymer binding solvation energy on drag reducers. It is pointed out that the drag reduction efficiency is closely related to the polymer molecular structure, polymer molecular morphology and polymer concentration in solution.