The drilling chemical is used as modifiers of drilling fluid performance in petroleum exploitation. Polyacrylamide can be used to adjust the rheology of the drilling fluid, carrying cuttings, lubricating the bit and improving the drilling efficiency. In addition, it can greatly reduce sticking accidents, reduce equipment wear, and prevent lost circulation and collapse, which makes the well diameter regular. Partially hydrolyzed polyacrylamide is often used in this field.
Polymer flooding is to increase the viscosity of the injected water and improve the oil-water mobility ratio by adding a certain amount of polymer polyacrylamide to the injected water. Due to adsorption and trapping of the oil layer on polyacrylamide, it reduces the permeability of high and medium permeability layer or high water flooded layer, and increases the seepage resistance of injected water, making the low permeability layer or low without water layer increases, which expands the scope of the injected water on the oil layer and the depth of the water flooded in the longitudinal direction of the oil layer, thereby expanding the flooded volume and displacing the unused crude oil, reaching the purpose of improving the crude oil recovery.
In the process of oilfield production, due to the heterogeneity of the formation, water flooding often occurs, which requires water plugging. Its core is to change the permeability of water in the formation, so as to reduce the water production of oilfield, maintain the formation energy and improve the ultimate recovery. The effect of polyacrylamide chemical plugging agent on the permeability of the oil and water is selective. It has less permeability to the oil and more permeability to the water. Polyacrylamide can also be used to adjust the water injection profile and block the large pore channels in the formation, and good results have been achieved in practice.