胶态分散凝胶深度调剖技术在大庆油田聚驱开发中的应用

介绍了大庆油田应用胶态分散凝胶深度调剖技术的凝胶成胶机理、影响成胶的因素、凝胶在多孔介质中的渗流特征及现场试验效果，室内岩芯模拟研究及现场典型井试验表明，流动凝胶在多孔介质中可流动，在单井注入15000－20000m^3流动凝胶体系过程中，注入压力逐渐升高，可以实现深度调剖，更好地提高聚合物驱采收率。     

利用二氧化碳的缓慢释放控制聚丙烯酰胺在含柠檬酸铬水溶液中的粘度

Partially hydrolyzed polyacrylamide (HPAM) has been widely used for water shut-off and profile control to enhance oil recovery. Herein, we reported a novel technique by which the crosslinking between HPAM and Cr³⁺ in aqueous solutions at 60 ℃ can be delayed effectively. Citric acid was selected as an organic complexing agent of Cr³⁺ so that the crosslinking between HPAM and Cr³⁺ can be prevented completely. Due to the decomposition of the bicarbonate (HCO₃^-) embedded in solution, CO₂ released from solution and the pH value of solution increased gradually. The degree of ionization of HPAM and its ability to complex with Cr³⁺ increased accordingly. When the complexation of Cr³⁺ with HPAM is stronger than that with citric acid, the viscosity of the HPAM solution increased significantly. Under the closed condition, together with the existence of potassium dihydrogen phosphate (KH₂PO₄), the release of CO₂ was very slow and the condition was highly controlled so that the ionization of HPAM was prevented initially. Furthermore, the hydrogen bonding interactions between HPAM and melamine embedded in solution previously also postponed the ionization of HPAM. As a result, the crosslinking between HPAM and Cr³⁺ can be delayed for almost one month, completely meeting the requirements for deep water shut-off and profile control to enhance oil recovery.     

三元复合驱硅垢防垢剂SY-KD的合成及应用

通过分析三元复合驱油体系下硅垢的形成机理,设计合成了新型硅防垢剂SY-KD.SY-KD是由丙烯酸(AA)和对甲基烯丙基氧基苯磺酸(MBS)共聚形成的高分子(CAABS)与2-膦酸丁烷-1,2,4-三羧酸(PBTC)复配的混合物.SY-KD中羧基官能团通过氢键相互作用与原硅酸分子或其二聚体发生键合,由于SY-KD分子链的空间位阻效应,阻止了原硅酸分子或二聚体进一步聚合形成二氧化硅.室内研究结果表明,SY-KD各组分对于硅垢的阻垢能力主要是通过阻聚、吸附分散以及对不溶性SiO2的溶蚀作用来实现的,是一种很好的三元复合驱阻垢剂.SY-KD防垢剂使结垢油井平均检泵周期由50 d左右增加到300 d.     

基于正交试验法和数值仿真的环形降压槽结构优化

降压槽存在相互矛盾的阻力和粘损特性均受各结构参数的影响,合理的结构参数选择一直是降压槽设计的难点问题.环形降压槽结构优化设计涉及到多因素多水平问题,数值仿真和正交试验设计方法相结合可以有效地减少对实验的依赖和试验次数.对环形降压槽进行结构参数化建模,建立了幂律流体在降压槽环空流道流动的数值仿真模型,可完成不同结构降压槽性能的数值仿真分析;制定了降压槽3因素3水平的多指标正交试验,采用极差和方差分析方法对试验的结果进行了分析,并用综合平衡的方法确定最优的降压槽结构参数组合.最终得到了各结构参数对降压槽的粘损和阻力性能的影响规律以及最优的结构参数,可为环形降压槽的设计和改进提供有价值的参考.     

大庆油田三元复合驱结垢样品中碳酸钙的结晶特性及形貌特征

采用EDAX, XRD和SEM等方法对大庆油田三元复合驱结垢样品中碳酸钙的结晶特性及形貌特征进行了研究. 结果表明, 结垢样品中的碳酸钙呈现出球形、棒状和花状等形貌特征和层状生长的结晶特征. 部分水解聚丙烯酰胺(HPAM)降低了重烷基苯磺酸盐(HABS)表面活性剂的临界胶束浓度(cmc), 促进了其胶束化作用; HABS使溶液中HPAM链的刚性增强, 负电吸引能力增强; 二者均会形成模板, 导致结垢样品中的碳酸钙具有不同的形貌特征. 聚丙烯酰胺和表面活性剂的存在未改变结垢样品中碳酸钙的层状生长特征.