【作者】 赵健；

【导师】 康万利；

【作者基本信息】 中国石油大学(华东) ， 油气田开发工程， 2015， 硕士

【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%。更多还原

【Abstract】 The central north part of Dagang oil field is typical of unconsolidated sandstone structure.Severe heterogeneity of oil-bearing formations cause poor plugging effect of ordinary profile control agent.Preformed particle gel can modify reservoir heterogeneity and enhance oil recovery effectively.But the strength of existing particles is typically high,which leads to poor deformability.Therefore,this paper presents a new kind of preformed particle gel with low elasticity and easy deformation,and basic properties and compatibility with oil reservoir were investigated.A type of preformed particle gel with low elasticity and high viscosity(D-PPG)was prepared using solution polymerization method.According to the viscoelastic strain,the synthesis conditions of preformed gel were optimized.The preformed particle gel(D-PPG)was characterized by FTIR spectra.The thermal stability of D-PPG was studied by DSC and TG.The three dimensional network structure of swollen preformed particle gel was observed by ESEM.Swelling kinetics of D-PPG were simulated and analyzed,and the influence of different environmental factors on D-PPG swelling behaviors was obtained.The initial swelling stages were thought to be controlled by the non-Fickian diffusion.The whole swelling process was well fitted into the Schott second-order kinetic equation.The initial swelling rates,the equilibrium swelling ratio and swelling time of D-PPG increased with the temperature increasing.The swelling ratio of D-PPG decreased with metal ion concentration increasing,divalent ions having greater shielding effect than monovalent ion.The swelling ratio of D-PPG increased with pH value increasing.D-PPG/HPAM disperse system exists the critical shear rate.When the shear rate is lower than the critical value,the system showed shear thinning properties,and it shows shear-thickening behavior when shear rate higher than this value.particles make great influence on the viscosity of the system.The phenomenon of shear-thickening is much more obvious with increasing D-PPG concentration in high shear rate.The matching relationship between preformed particle gel and pore throat and the profile control property were studied by using sand packed tube model.Then,the filtration and the damage extent of preformed particle gel were evaluated by using high temperature static loss test.Pore throat of cores and swollen D-PPG sizes had better compatibility when the diameter ratio was approximately 0.05.Preformed particle gel has selective profile control ability to oil and water as well as high permeable layer.D-PPG/HPAM disperse system shows significant ability of fluid diversion when permeability contrast increased.The water plugging rate of preformed particle gel is higher than its oil plugging rate.The filtration of D-PPG may cause damage on low permeability layer,but when the filter formed by filtration is removed,the effect of profile control will be improved.HPAM and D-PPG can make influence cooperatively on plugging dominant channel,changing direction of fluid flow and expanding sweep efficiency.D-PPG/HPAM disperse system can significantly decrease formation heterogeneity.Results of parallel heterogeneity model experiments show that D-PPG/HPAM disperse system can improve recovery factor 17.56% after polymer flooding when the permeability contrast is 10.更多还原