交联聚合物性能及调驱机理研究

【作者】 胡勇；

【导师】 卢祥国；

【作者基本信息】 大庆石油学院 ， 油气田开发， 2005， 硕士

【摘要】 在水驱和聚合物驱油过程中,由于油藏的非均质性,注入水和聚合物溶液主要进入高渗透层,中低渗透层波及程度低,影响水驱和聚合物驱开发效果。近年来,为了实现油田稳产高产,进一步提高水驱和聚合物驱采收率,广大石油科技工作者对交联聚合物溶液性质进行了大量研究,矿场应用也取得了较好的增油降水效果。与室内实验结果相比较,矿场交联聚合物溶液调驱效果还存在较大差异,人们对交联聚合物溶液调驱机理还缺乏深入认识是其原因之一。本文在吸取现有室内研究成果和矿场施工经验的基础上,通过室内实验和理论分析方法,对复合离子交联聚合物溶液、有机铬交联聚合物溶液、柠檬酸铝交联聚合物溶液性质进行了系统研究,完成了交联聚合物调驱体系配方优选、驱油效果评价、渗流特性、成胶时机以及成胶机理、性能特征及其评价方法等多方面研究。研究结果表明,聚合物成胶时具有分子间和分子内部交联两种形式。当以分子间交联为主时,交联聚合物溶液表观黏度呈现大幅度增加;当以分子内部交联为主时,交联聚合物溶液表观黏度基本保持不变。岩心流动实验结果表明,与相同黏度的聚合物溶液,分子内部交联聚合物溶液的阻力系数和残余阻力系数要大得多,并且表现出独特渗流特征即残余阻力系数大于阻力系数。交联聚合物溶液性能评价方法研究结果表明,阻力系数、残余阻力系数、转变压力是描述成胶情况的最有效指标,将黏度与阻力系数和残余阻力系数相结合就可以实现对交联聚合物分子结构形态的识别。实验结果还表明,交联聚合物溶液在注入初期黏度低、流动性好,容易进入高渗透层,可以发挥驱油作用,形成凝胶后就可以对高渗透层实施有效封堵。更多还原

【Abstract】 During the water flooding and polymer flooding, water and polymer solution mainly are injected into high permeability because of the heterogeneity exiting in layer, which will affect the development effectiveness. To modify the layer’s heterogeneity, enhance the recovery after water flooding and polymer flooding, turn the high production and stable production into realization, in recent years, many researches have been done on cross-linked polymer gel by many scientists, but just a little on the profile modification and flooding mechanism of cross-linked polymer gel, this is one of the reason that leads to the difference of profile modification and flooding effectiveness. On the base of many laboratory experiments and field construction, using many methods, such as physical modification, orthogonal design, transition pressure test system and so on, this paper has researched composite ion, Al3+ and Cr3+ cross-linked gel and has completed the research of project’s priority selection, oil displacement efficiency, flowing and gel-forming characteristics in porous medium, cross-linking time, cross-linking mechanism, evaluation methods and so on. The results show that there are two kinds of structure, intra-molecular cross-linking and molecular to molecular cross-linking, When intra-molecular cross-linking plays the main role in gel, the viscosity will increase greatly, and when molecular to molecular cross-linking plays the main role, the viscosity almost keeps invariable. The results of sealing off core test show that both of resistance factor (FR) and residual resistance factor (FRR) for gel are much bigger than those of polymer solution, and appears its own special flow characteristic, the FRR is bigger than the FR. The result of evaluation test shows that the transition pressure, FR and FRR are the direct and available index to estimate whether polymer molecular has intra-molecular cross-linking or molecular to molecular cross-linking. The results of cross-linked polymer gel’s profile modification and flooding mechanism show that at the first period of gel-forming, cross-linking polymer has low viscosity and good flowing characteristic, and can play the part of flooding. But after gel-formed in core, it has good intensity and stability, and can modify the profile effectively. The technique just is united in reason by flooding and profile modification.更多还原