可分解聚合物微球的二次交联性能研究

Study on the secondary crosslinking performance of Labile Polymer Microspheres

摘要:

以丙烯酰胺(AM)、2-甲基-2-丙烯酰胺基丙磺酸(AMPS)为原料，采用反相乳液聚合法合成了可分解聚合物微球，微球形貌为不规则球形颗粒，尺寸与油藏的微米/亚微米级孔吼尺寸相匹配，红外光谱结果证实合成产物为P(AM-AMPS)。二次成胶实验结果表明，成胶时间随矿化度增加而延长，随温度，聚合物微球加量增大显著缩短。第二交联剂FQ加量对成胶时间影响不大，但对成胶强度影响显著。当温度>90℃，可分解聚合物微球加量为1.5%~2%，第二交联剂FQ加量为0.5%~1.2%，得到的二次交联凝胶成胶时间可控，为1~3天，热稳定性良好，30天不脱水。在油相中，可分解聚合物微球不发生二次交联，从而间接证明其具有选择性封堵性。SEM实验证实了可分解聚合物微球的二次成胶过程，即颗粒间交联形成颗粒聚集体，颗粒聚集体交联形成大的团聚体，最后形成本体胶。

Abstract:

Labile polymer microspheres were prepared by inverse emulsion polymerization by using acrylamide (AM), 2 - methyl - 2 - acrylic amide propyl sulfonic acid (AMPS) as monomers. Morphology of labile polymer microspheres is irregular spherical particles, microsphere size matches the micro/sub-micro size of pore throat. The structure of labile polymer microspheres were confirmed by Infrared spectroscopy. Secondary gelling results show that the gelling time extended with the increase of salinity and apparently shortened with the increase of temperature, Secondary crosslinker FQ has little effect on gelling time, but significantly affect gel strength. the gel with controllable gelling time（about 1 ~ 3 days）,good thermal stability and without dehydration can be obtained when the temperature > 90 ℃, degradable polymer microspheres with amount of 1.5% ~ 2% and the secondary crosslinker FQ with amount of 0.5% ~ 1.2%. In the oil phase, degradable polymer microspheres can’t conduct secondary crosslinking which indirectly prove its plugging selectivity . SEM experiment confirmed that the secondary gel process of degradable polymer microspheres, namely particles crosslinked to form particles aggregate, and then particle aggregats crosslinked to form large aggregate and the finally to form bulk gel.