以丙烯酰胺/丙烯酰吗啉/N-乙烯基吡咯烷酮共聚物(AAN)为成胶剂、对苯二酚和乌洛托品为交联剂、硫脲为除氧剂、纳米SiO2 为高温稳定剂制备了冻胶,研究了聚合物、交联剂、除氧剂和高温稳定剂用量对冻胶成胶性能和热稳定性的影响.实验结果表明,聚合物链上伯酰胺基的水解是冻胶在高温下热稳定性差的主要原因,加入纳米SiO2 可有效抑制水解从而提高冻胶的强度和热稳定性.优化的冻胶组成为1.0％(w)热敏聚合物AAN、0.4％(w)对苯二酚、0.4％(w)乌洛托品、0.2％(w)硫脲、2.0％(w)纳米SiO2,该冻胶在 165℃下的成胶时间为 3 h,成胶后弹性模量为 93.2 Pa,可在 90 d内保持冻胶强度级别为H,脱水率小于 5％;该冻胶对高渗通道有良好的封堵能力,封堵率在 99.5％以上.

Cyclic steam stimulation is an effective thermal recovery method for heavy oil recovery. The key potential mechanism is the growth of the steam chamber after steam injection. Taking the LD5X heavy oil reservoir as an example, besides the interlayer developed in this area, the top water and bottom water distribute above and below the interlayer. These factors may have adverse effects on the development of the steam chamber, thus affecting the final heavy oil exploitation. In this work, our goal is to study the effects of interlayer permeability and well–interlayer distance on CSS performance (in the presence of top and bottom water). We developed a high-temperature-resistant interlayer. Based on the simulated interlayer, the field scale model was converted into a laboratory element model through the similarity criterion. In order to quantitatively evaluate the performance of steam stimulation, a thermal detector was used to measure the dynamic growth of the steam chamber and record the production data. The experimental results show that the self-made interlayer has high-temperature resistance, adjustable permeability, and little difference between the physical parameters and the target interlayer. During the cyclic steam stimulation process, the steam chamber presents two different stages in the presence of the top water area, namely the normal production stage and the top water discharge stage. The bottom water has little effect on the growth of the steam chamber. The small interlayer permeability, the increase in horizontal well–interlayer distance, and the existence of the interlayer will delay the top water leakage during steam stimulation. This study has reference significance for us to develop heavy oil resources with a top water barrier when implementing steam stimulation technology.

纳米二氧化硅是目前应用最为广泛的一种纳米材料,但其团聚行为对粒径测量和应用效果有不利的影响.为减少纳米二氧化硅颗粒的团聚行为,应用动态光散射粒度分析方法,考察了分散方式、分散剂种类、悬浮液条件对不同纳米二氧化硅的粒径及多分散性指数(PDI)的影响规律.实验结果表明,磁力搅拌条件下,0.1％(质量分数)的PEG-2000对各类纳米二氧化硅均具有较好的分散效果;随着悬浮液pH增大,硅溶胶悬浮液粒径和PDI均呈下降趋势,是因为悬浮液pH影响了硅溶胶的溶解平衡;而固态二氧化硅悬浮液的粒径和PDI则呈先上升后下降的趋势,这是由于悬浮液pH影响了双电层结构.实际测试和应用中应注意悬浮液配制条件和纳米二氧化硅类别对粒径和PDI的影响.

对国内外Fe3O4磁性纳米颗粒的表面改性方法及其油气田开发领域应用现状进行了系统调研,按照其表面功能化改性材料划分为无机材料改性、有机小分子材料改性、有机高分子材料改性.功能化改性后Fe3 O4磁性纳米颗粒在油气田开发领域中应用时包括在提高采收率、污水处理、石油机械保护等方面,具有良好的应用前景.并对其在油气田开发领域应用发展进行了展望,指出开发出具备特异性功能的磁性纳米颗粒,进一步改善其表面性质、负载功能基团的吸附量和稳定性,降低生产成本是该领域的主要研究方向.