中低渗透高温高盐油藏驱油共聚物P(AM/AMPSNa/AANa)的合成及性能

在中低渗透高温高盐油藏聚合物驱技术中, 超高相对分子质量聚丙烯酰胺(HPAM)存在不易注入、剪切降粘显著和耐温抗盐性能差等问题。 本文以丙烯酰胺(AM)和2-丙烯酰胺基-2-甲基丙磺酸(AMPS)为单体, 采用过硫酸胺(NH₄)₂S₂O₈和甲基丙烯酸N, N-二甲氨基乙酯(DMAEMA)作为支化结构复合引发体系, 通过共聚后水解工艺, 合成含支化结构耐温抗盐驱油共聚物P(AM/AMPSNa/AANa)。 研究了引发温度、链转移剂用量、引发剂用量对共聚物特性黏数的影响, 并通过红外光谱(IR)和¹³C NMR表征了产物结构。 筛选特性黏数1915 mL/g左右的共聚物, 进行性能评价。 实验结果表明, 共聚物具有优异的耐温抗盐性能、抗剪切性能、抗老化性、注入性和驱油性能, 可应用在中低渗透高温高盐油藏三次采油中。

Preparation and Properties of Flooding Copolymer P(AM/AMPSNa/AANa) for High-temperature and High-salinity Oil Reservoir with Mid-Low Permeability

Due to the constraints of the factors such as poor injectivity, mechanical shearing degradability, temperature-tolerated and salt-resisted ability, hydrolyzed polyacrylamide(HPAM) with high relative molecular mass has no obvious oil recovery in polymer flooding in mid-low permeability oil reservoirs. The temperature-tolerated and salt-resisted copolymer P(AM/AMPSNa/AANa) with micro-branched structure was synthesized by solution polymerization of acrylamide(AM), 2-acrylamide-2-methylpropanesulfonic acid(AMPS) with ammonium persulfate(APS)/N, N-dimethylaminoethyl methacrylate(DMAEMA) as initiating system. Influences of the reaction temperature, chain transfer agent, initiator content on the intrinsic viscosity of copolymer were investigated. The structure of copolymer was characterized by IR and ¹³C NMR spectra. The properties of copolymer with intrinsic viscosity 1915 mL/g were evaluated. The results indicate that the copolymer has superior shear-resistence, temperature-tolerance, salt-resisting, aging property, injection and displacement efficiency, which can be used as targeted flooding polymer in high-temperature and high-salinity oil reservoir with mid-low permeability.