| Salt resistance of Polymer KYPAM (Comb Shaped Salt Tolerant Acrylamide Copolymer, whose molecular weight is 17,000,000 -19,000,000 and hydrolysis degree is 25-30%) was compared to 3630s according to reservoir features, brine and technical countermeasures for water control and oil stabilization in the Pucheng Sa Er2+3 of ZhongYuan oil field. Laboratory tests on hydrolysis, gelation and applications of Copolymer KYPAM with better salt tolerant were carried out.Copolymer KYPAM was influenced by concentration and type of salt, pH value, shear-rate, and hydrolysis of high temperature, oxygen, Fe2+, Fe3+ and H2S. Further researches were carried out through viscosity decline by fresh brine and analysis of hydrolysis mechanism and corresponding treatments for each influencing factor.The results proved that Copolymer KYPAM had better resistance to monovalent cations but divalent cations hydrolysis it seriously and its viscosity decreased to 5mPa.s with 2000mg/L divalent cations, 80℃; the viscosity of Copolymer KYPAM decreased to 5~10mPa.s with increase of shear-rate especially in the condition of salt; higher temperature and oxygen result in viscosity decrease of Copolymer KYPAM; its viscosity drastly decreased from 35.9mPa.s to 1.63mPa.s in 1 hour by 3~5mg/LFe2+, But Copolymer KYPAM can be hydrolysis by 40mg/LFe3+; 10mg/LH2S result in the loss of its viscosity in 2 hours because H2S can reduce Fe3+ to Fe2+ in brine as a kind of strong reducer; Copolymer KYPAM in brine had no viscosity because it was quickly hydrolysis by the fresh brine including Fe2+, Fe3+ and H2S. A serial ofcorresponding methods have been decided to control different hydrolysis such as the mix of fresh and brine to high concentration of salt, the removal of Fe2+ and H2S by oxygen, the adsorption of H2S in brine by AS, which is developed by laboratory, hydrotalcite and aldehydes. So it is very important to remove Fe2+, Fe3+ and H2S to ensure the gelation of Copolymer KYPAM.The gelation between different crosslinkers(organic chromium, phenolic resinCR-1, phenol and the complexion system of chromium and phenol) and Copolymer KYPAM was studied on the basis of the lest hydrolysis according to the hostile reservoirs of Pucheng oil field with 81 °C, 6~10x104mg/L salt. The results are found after research of the influence factors, such as pH, temperature, salinity and the dosage of crosslinker and the concentration of Copolymer KYPAM. Polymer gel system between four crosslinkers and Copolymer KYPAM had higher viscosity 2000~6000mPa.s. The gelation of CR-1 was same to phenol in the same temperature. These(10x104mg/L salt, optimum pH 3-10) had more salt resistance and antiacid alkali performance than organic chromium(3xi04mg/L salt, optimum pH4~8) and the complexion system(6x104mg/L salt). The system of phenol had good thermal stability because the viscosity of CR-1 and phenol remained 95.6% and 89.3% respectively but organic chromium and the complexion system remained 59.6% and 61.1% respectively. The obvious increase of thermal stability was from the molecular network containing beznene rings. The mechanism on dehydration of organic complex and the formation of network holes were studied by using Atomic Force Microscope and was considered into hererogeneity of gelation.The viscoelastic effects of phenol in porous media was described by using core flow experimental method. Profile modification arrived by 80% andenhanced oil recovery increased by 12.6%~28.3% after using gelation of phenol. Based on the application of the profile control decision and the decision of injection parameters, slug optimization and the prediction and analysis, 40 injection wells in the Pucheng oil field by using profile modification had good effect that the total increased yield is 811t in 4 months and each well remains effective.
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