黄原胶增粘地下交联暂堵剂体系的研究

Study on the xanthan gum thickening plugging agent crosslinked underground

针对缝洞型油藏区块油水同出的问题,以丙烯酰胺、2-丙烯酰胺-2-甲基丙磺酸、丙烯酸为聚合单体,黄原胶为增稠剂,N,N-亚甲基双丙烯酰胺为交联剂,过硫酸钾为引发剂,采用自由基聚合方法,设计开发了一种可在地下聚合交联形成凝胶的暂堵用剂体系。考察了固含量和交联剂用量对暂堵剂体系的初始粘度、成胶时间和凝胶强度的影响。结果表明,黄原胶加入可有效增加体系粘度,随交联剂用量增加,抗压强度增加,成胶时间缩短。凝胶产物在250℃高温下没有明显的热分解,可用于高温碳酸盐岩地层的封堵。在蒸馏水和模拟地层水中,凝胶产物的溶胀动力学均满足二级动力学模型。

The bottom water is difficult to control for producing wells in the fractured-cavity carbonate reservoirs.In order to achieve the purpose that the free radical polymerization happened in the underground,the polymer gel used for plugging agent was synthesized using acrylamide,2-acrylamide-2-methylpropanesulfonic acid,acrylic acid as polymerization monomer,xanthan gum as thickener,N,N-methylene bisacrylamide as crosslinking agent and potassium persulfate as initiator.The effects of monomer content and the dosage of crosslinking agent on viscosity,gelation time and compressive strength of the polymer gel were investigated.The results show that xanthan gum can effectively increase the viscosity of the system,and the compressive strength increases with the increasing crosslinking agents,but the gelation time reduce.And there was no obvious thermal decomposition at 250℃,which could be used for plugging off the carbonate reservoirs.The swelling kinetics of the gel products satisfied the second-order kinetic model in distilled water and simulated formation water.