Application of PHPA polyacrylamide(PAM FLOCCULANT) in oil field
1. Polyacrylamide used as drilling fluid regulator:
Partially hydrolyzed polyacrylamide Hp is often used, which is obtained from the hydrolysis of polyacrylamide. Its function is to adjust the rheological property of drilling fluid, carry cuttings, lubricate drill bit, reduce fluid loss and so on. With PAM modulation of drilling mud weight is low, can reduce the pressure of the oil and gas layer and congestion, easy to find oil and gas layer, and is helpful for drilling, drilling speed is higher than conventional mud 19%, about 45% higher than the rate of penetration, in addition, still can greatly reduce sticking accidents, reduce equipment wear and tear, and can prevent lost circulation and collapse.
2. Polyacrylamide as an oil displacement agent:
The use of polyacrylamide as displacement agent plays an important role in tertiary oil recovery methods for enhancing oil recovery. The function of polymer is to adjust the rheological properties of injected water, increase the viscosity of driving fluid, improve the efficiency of water flooding wave generation, reduce the permeability of water phase in the formation, and make water and oil flow forward uniformly. When micellar/polymer flooding is used, microemulsion with ultra-low interfacial tension combined with surfactant and additives is injected into the water injection well, followed by polymer solution, and finally water injection. Water moves forward as a plunger flow to displace residual oil dispersed in the pores and improve recovery. Polyacrylamide used for tertiary oil recovery is generally 10%-50% by weight, and its relative molecular weight ranges from hundreds of thousands to more than ten million. Large oilfields in China, including Daqing, Shengli, Liaohe and Dagang, have entered the middle and late stage of production, and the comprehensive water content of produced oil is increasing day by day. In order to stabilize oil production in eastern China, it is imperative to adopt tertiary oil recovery technology to improve oil recovery rate and ensure stable oil production. The experiment of polyacrylamide flooding in Daqing oilfield has been popularized in industry and achieved good oil increasing effect.
3. Polyacrylamide used as fracturing fluid additive:
Fracturing technology is an important stimulation measure for tight formation development. The fracturing fluid made of methylene polyacrylamide crosslinking is widely used because of its high viscosity, low friction resistance, good sand suspension ability, small filtration, good viscosity stability, less residue, wide supply and convenient preparation and low cost.
4 polyacrylamide used as a water plugging regulator:
In the process of oilfield production, due to the heterogeneity of the formation, the problem of water flooding often occurs, and water plugging is needed. The essence of water plugging is to change the seepage state of water in the formation, so as to reduce the oil field water production, maintain the formation energy, and improve the ultimate oil recovery. Polyacrylamide chemical water plugging agent has the selectivity of oil and water permeability, oil permeability can be reduced by up to 10%, and water permeability can be reduced by more than 90%. Selective water plugging this feature is not other water plugging agent, usually according to the formation type to choose the appropriate polyacrylamide molecular weight. For reservoirs with good homogeneity and high average permeability, polyacrylamide with medium molecular weight of 5x106-7x106 can be selected. High molecular weight 10x107 polyacrylamide can be selected for fractured reservoirs with low permeability of bedrock or reservoirs with large permeability changes. Polyacrylamide can not be crosslinked when used, but also can be crosslinked with aluminum salt, chromium salt, zirconium salt and other gel use, but also can add some resins to form a mutually capacitive polymer network, so that it has higher temperature resistance. This method has been applied to water plugging of high water-cut carbonate bottom water reservoir in China and achieved obvious results. Polyacrylamide can also be used to adjust the water absorption profile in the formation and block large pores. Good results have been obtained in practice.