低弹高粘PPG制备及与油层配伍规律研究

发布时间：2018-12-06 11:17

【摘要】：大港中北部油田为典型的疏松砂岩,油藏非均质性严重,常规调剖体系封堵效果差。预交联凝胶颗粒可以改善油藏的非均质性,提高原油采收率。而现有的颗粒强度大、可变形性差,易在地层中滞留和剪切破坏。因此,本文提出一种弹性低易变形的预交联凝胶颗粒,并探讨了其基本性能和油层的配伍性。采用溶液聚合法成功制备了一种低弹高粘预交联凝胶颗粒(D-PPG),并以粘弹性应变为依据探讨了合成的最佳反应条件,红外光谱法表征相应官能团原子间键的振动吸收峰,差示扫描热量法表征了D-PPG的热稳定性能,环境扫描电镜观察证实了D-PPG吸水膨胀后仍具有三维的空间网络结构。对D-PPG膨胀过程动力学进行了模拟分析,获得了不同环境因素对D-PPG膨胀的影响规律。D-PPG膨胀初期符合non-Fickian扩散;而整个膨胀过程符合Schott二级动力学模型,温度升高D-PPG的初始膨胀速率和最大膨胀率都是依次增大的,而达到最大膨胀率的时间越长。随着金属离子浓度升高D-PPG膨胀率减小,二价金属离子具有比一价金属离子更强的屏蔽作用;pH升高,D-PPG膨胀率变大。D-PPG/HPAM分散体系存在临界剪切速率?(8。剪切速率低于该值时,体系表现为剪切变稀性;剪切速率高于该值时,表现为剪切增稠性;颗粒的存在对体系的粘度影响较大。D-PPG浓度越大高剪切速率下剪切增稠现象越明显。采用填砂管模型研究了D-PPG与孔喉的匹配性以及调剖性能,采用高温静态滤失仪研究了D-PPG静态滤失特性和对低渗透层造成的伤害程度。当孔喉直径与D-PPG粒径的匹配因子R在0.05左右时,具有较好的注入性。D-PPG/HPAM分散体系具有选择性调剖作用,且渗透率级差越大,剖面改善能力越明显;对水的封堵率比油高。聚合物的加入携带性增强,降低了滤失,减小了对低渗管的伤害。分散体系向低渗管的滤失会伤害低渗层,清除滤饼会增加调剖的效果。聚合物和D-PPG发挥协同作用,封堵优势通道,改变液流方向,扩大波及系数;分散体系能显著改善双管并联模型的非均质性,渗透率级差为10的并联填砂管在聚驱后采用D-PPG/HPAM分散体系驱油效率可达17.56%。
[Abstract]:Dagang central and northern oil field is a typical loose sandstone, the reservoir heterogeneity is serious, and the sealing effect of conventional profile control system is poor. Pre-crosslinked gel particles can improve reservoir heterogeneity and oil recovery. However, the existing particles have high strength, poor deformability, and are easy to be detained and shearing failure in the strata. Therefore, a precrosslinked gel particle with low elasticity and easy deformation was proposed, and its basic properties and compatibility of oil layer were discussed. A low elasticity and high viscosity pre-crosslinked gel particle (D-PPG) was successfully prepared by solution polymerization. The optimum reaction conditions were discussed based on viscoelastic strain. The vibrational absorption peak of the bond between atoms of the corresponding functional group was characterized by infrared spectroscopy. The thermal stability of D-PPG was characterized by differential scanning calorimetry (DSC). The results of environmental scanning electron microscopy (SEM) confirmed that D-PPG still had a three-dimensional spatial network structure after water absorption and expansion. The kinetics of D-PPG expansion process was simulated and analyzed, and the influence of different environmental factors on D-PPG expansion was obtained. D-PPG expansion was consistent with non-Fickian diffusion at the initial stage of expansion. The initial expansion rate and the maximum expansion rate of D-PPG are increased in turn, and the time to reach the maximum expansion rate is longer. With the increase of the concentration of metal ions, the D-PPG expansion ratio decreases, the bivalent metal ions have stronger shielding effect than the monovalent metal ions, and the D-PPG expansion rate increases with the increase of pH. The critical shear rate of the D-PPG/HPAM dispersion system is 8. When the shear rate is lower than this value, the system exhibits shearing thinning, and when the shear rate is higher than this value, it shows shear thickening. The existence of particles has a great influence on the viscosity of the system. The higher the concentration of D-PPG is, the more obvious the phenomenon of shear thickening is at higher shear rate. The matching property and profile control performance of D-PPG and pore throat were studied by using sand filling pipe model. The static filtration characteristics of D-PPG and the damage degree to low permeability layer were studied by using high temperature static filtration apparatus. When the matching factor R of pore throat diameter and D-PPG diameter is about 0. 05, it has better injectability. The D-PPG/HPAM dispersion system has selective profile control, and the greater the permeability difference, the more obvious the profile improvement ability. The plugging rate of water is higher than that of oil. The addition of polymer enhanced the portability, reduced the filtration loss and reduced the damage to the low permeability pipe. The filtration loss of the dispersion system to the low permeability pipe will harm the low permeability layer, and the filter cake will increase the effect of profile control. Polymer and D-PPG play a synergistic role in blocking the dominant channel, changing the direction of the liquid flow and expanding the sweep coefficient. The heterogeneity of the two-pipe parallel model can be significantly improved by the dispersion system. The oil displacement efficiency of the parallel sand filling pipe with permeability difference of 10 can reach 17.56 after polymer flooding with D-PPG/HPAM dispersion system.
【学位授予单位】：中国石油大学(华东)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE39

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