【作者】 韩杰；

【导师】 汤达祯；

【作者基本信息】 中国地质大学（北京） ， 油气田开发工程， 2010， 博士

【摘要】 本文系统研究了高温油藏条件下应用聚合物驱以及三元复合驱的可行性,对聚合物粘弹性在驱油过程中的作用及三元复合驱的驱油机理及配方筛选进行了深入探讨。在大量的国内外有关聚合物驱及三元复合驱理论和应用研究进展调研的基础上,对聚合物的热稳定性进行评价,研究聚合物流变性及粘弹效应对提高采收率的作用,考查了复合驱三种组分对界面张力的影响,并结合配方筛选和物模实验确定体系最佳配方。全文研究的主要内容有以下几个部分:1、聚合物的长期热稳定性研究。提出高温油藏进行聚合物驱时,聚合物的水解作用对保留粘度有积极作用。评价了两种稳定剂,其中低浓度多羟基化合物作为稳定剂,既提高了聚合物溶液的化学稳定性,又可以有效控制体系粘度的增长速度。2、利用流变研究方法研究聚合物的流变性,考查浓度对聚合物粘弹性的影响以及粘弹性对驱油效率的作用。得出浓度达到一定程度后（本实验所用两种聚合物浓度需达到1600mg/L）,才会表现出明显的粘弹性。3、通过三种粘度相同、弹性不同的驱替液的渗流实验,得出具有弹性的聚合物提高驱油效率要高于弹性很低的黄原胶和没有弹性的甘油,说明弹性对提高驱油效率有积极作用,而粘性对提高驱油效率影响较小。4、物模实验。研究了不同浓度、不同段塞、不同渗透率级差条件下的聚合物提高驱油效率的大小,以及老化前后由于水解作用引起的粘弹性变化对提高采出程度的影响,实验得出适合该油藏条件的聚合物质量浓度为2000 mg/L,段塞尺寸为0.4-0.5PV。5、三元复合驱体系配方研究。当表面活性剂或碱的浓度处于一定的范围内时,复合体系的界面张力能取得最小值。复合体系的粘度主要由聚合物的浓度控制,表面活性剂的浓度不影响体系的粘度,而是影响体系界面张力的最主要因素。测定了三组分的静吸附量。研究结果证明了聚合物和碱对活性剂有明显的保护作用。6、开展了一系列复合体系的渗流实验。研究结果表明,界面张力大小是复合驱大幅提高采收率的主要因素。提出不同水油粘度比对驱油效率的影响,得出随着水油粘度比增大,提高采收率幅度不断增加,但在粘度比大于8.4后,增加幅度变缓。考虑吸附以及经济等因素影响,体系0.25%S-3+1500mg/L聚合物+0.5%Na₂CO₃由于保持了较高的粘度而具有较好的提高采收率效果,室内实验结果比水驱提高采收率22%。更多还原

【Abstract】 This paper studies systematically about the feasibility application of the visco-elastic polymer flooding and Alkaline/Surfactant/Polymer（ASP） flooding under the conditions of high-temperature reservoir.In addition,the function of polymer visco-elastic and the displacement mechanism has been lucubrated.On the basis of studying a large number of domestic and foreign theoretical literature about polymer flooding and ASP flooding,we have studied the polymer thermal stability,the polymer rheological and viscoelastic effection on enhancing oil recovery under the conditions of high temperature,the three components of ASP flooding displacement mechanism,as well as their synergistic effect.Based on the results, polymer flooding and ASP flooding has been optimized and screened out.This dissertation is divided into the following sections,and will be descripted briefly:1,long-term thermal stability and visco-elasticity of polymer.Under the conditions of high-temperature,the stability of the polymer displacement fluid played a very important role. Two kinds of stabilizers were evaluated.It was first proposed that a low concentration of polyhydroxy compound stabilizer can enhance the chemical stability of the polymer solution, and can effectively control the viscosity grow rate.The results of physical simulation show that injection velocity on the polymer solution can increase flexibility,thereby it can enhance oil displacement efficiency.When the injection velocity is higher than 0.5mL/min,the system showed a higher viscoelasticity.Under the same viscosity conditions,the high viscoelastic polymer flooding oil displacement experiments can reach a relatively higher efficiency.2,Study of polymer theology.We examined the impact of polymer concentration on the viscoelasticity and viscoelasticity on the role of oil displacement efficiency.The results showed that it was only concentration reaching a certain degree that it shows significant viscoelasticity.3,By three different elastic fluids but in the same viscosity flow experiments,we obtained that elasticity has a positive effect on enhancing oil recovery,while the viscosity is less.4,Physical flow experiments.We studied different concentrations polymer,different size and different penetration effect on the improving the efficiency,as well as changes in visco-elasticity caused by hydrolysis effected on enhancing oil recovery.It is obtained from experiments that the suitable polymer concentration is 2000 mg / L,and the slug size is 0.4-0.5PV. 5,Formulation of ASP flooding system.It showed that the composite system can achieve the minimum interfacial tension when the surface-active agent and alkali concentration was in a certain range.The viscosity was controlled mainly by the concentration of polymer,while surfactant concentration does not affect the viscosity,but it is the most important factor of effecting the interfacial tension system.We measured the static adsorption capacity of the three components.The results proved that the polymer and alkali has obvious protective effect on the of agents adsorption.6,A series of porous media flow experiments by ASP system have been done.The results showed that interfacial tension is the major factor of substantially increasing EOR,especially when the interfacial tension reached 10^-4 magnitude system,the effect is particularly evident. It is the first time to be proposed that different water-oil viscosity ratio has the impact on oil displacement efficiency.It is also obtained that with the water-oil viscosity ratio increased, the enhanced oil recovery rate is increasing.Meanwhile,the rate of increase slowed down when the viscosity ratio is more than 8.4.As the result,the range of the polymer concentration should be 1000～1500mg / L.Considering the absorption as well as economic and other factors,the system should be adoped as 0.25%QY-3 +1500 mg / L polymer +0.5% Na₂CO₃.As it can maintain a high viscosity,the system has a good effect on enhanced oil recovery of 22%.更多还原