节点文献
驱油聚合物的降解与稳定性研究
Study on the Degradation and Stability for Flooding Polymers
【作者】 张磊;
【导师】 谭业邦;
【作者基本信息】 山东大学 , 高分子化学与物理, 2011, 硕士
【摘要】 目前,由于在三次采油中聚合物驱技术的油藏温度高以及矿化度高等特点,驱油剂要达到理想的效果,必须具有很好的增粘能力和很强的耐温、抗盐及抗剪切能力。而在这一技术中,驱油聚合物溶液的粘度及长期稳定性是衡量聚合物驱油效果的重要指标之一,也是影响聚合物驱油效率的关键因素。本论文模拟研究驱油聚合物在不同油藏条件下的降解规律的影响因素,通过化学方法来研究驱油聚合物在海上三次采油过程中的热降解、化学降解和剪切降解规律,为改善驱油聚合物在不同油藏条件下的溶液性能提供理论依据,从而达到粘度改善的效果和稳定性。本论文的工作是基于上述研究背景以及发展趋势展开的,主要研究具有驱油聚合物的评价、粘度改善剂的合成、表征以及其实际应用性能等。主要工作和实验结果分为以下几方面:(1)结合目标油田的实际油藏状况,在实验室条件下模拟聚合物溶液的配注,研究在不同油藏下的热降解、化学降解、剪切降解对驱油聚合物(SNF和AP-P4)溶液粘度和稳定性的影响,并通过测试水解度、降解过程中的结构变化、热分析、降解前后的粘度变化和分子量变化、聚集体的流体力学半径等化学分析手段进行了表征。结果表明,三种降解方式都对驱油聚合物(SNF和AP-P4)体系起到了降粘作用,剪切降解的降粘作用最快。红外和热重分析表明在降解过程中驱油聚合物AP-P4和SNF的结构基本不发生变化。(2)合成了甘脲和四羟甲基甘脲两种物质,该类物质可以作为粘度稳定剂,并通过HNMR、粘度、动态光散射和粘弹性等方法进了表征。甘脲和四羟甲基甘脲可以作为驱油聚合物AP-P4的粘度稳定剂,结果显示可以明显提高体系的粘度,其中甘脲的增粘效果要好于四羟甲基甘脲;甘脲也可以作为驱油聚合物SNF的粘度稳定剂,结果显示可以较好地提高体系的粘度。(3)采用阳离子开环聚合法合成了一种新型的高分子表面活性剂(PQ),并使用三氟化硼乙醚作为阳离子开环的催化剂,高分子表面活性剂PQ的化学结构、表面活性和聚集性质通过核磁共振、静态光散射、动态光散射、表面张力、电导率和荧光测量等手段来表征。另外,该新型表面活剂可以作为粘度稳定剂,可与驱油聚合物(SNF)进行复配,稳定性结果表明,混合体系可以大大提高耐盐性和热稳定性,并具有较高的实际应用价值。
【Abstract】 At present, most of the oil layers are of high temperature and high salinity in EOR. In view of this, polymers used in oil field must have effective thickening properties, temperature tolerance, brine tolerance and resistance to shear force in order to achieve the ideal effect. In polymer flooding technology, the viscosity and long-term stability of polymer fluids are not only one of important index but also the key factor of polymer flooding effectiveness. A lot of literature research and practice tests show that the viscosity of polymer fluids has a direct impact on performance of polymer flooding agent solution.In the laboratory condition, we simulated the influencing factor in the different oil reservoir to study the degradation rules of flooding polymers. By chemical methods we studied the rules of thermal degradation, chemical degradation and shear degradation, in order to provide the theory basis for the improving the solution properties of flooding polymers under different oil deposit condition and achieve the improvement of viscosity and stability. Based on the above considerations, the purpose of this dissertation is focused on evaluation of flooding polymers, synthesis and characterization of viscosity stabilizer and their practical applications. The main work and experimental results are as follows:(1) Combined with the actual reservoir conditions of target oilfield, in the laboratory condition, the effects on viscosity and stabilization for flooding polymer (SNF and AP-P4) were studied under thermal degradation, chemical degradation, shear degradation in the different oil deposit, and were characterized by measuring the chemical structure, hydrolysis degree, thermal analysis, viscosity changes and molecular weight change, dynamic light scattering and so on. It is found that these three kinds of degradation methods can all decrease the viscosity of flooding polymers (SNF and AP-P4), in which shear degradation is most obvious for the reduction of viscosity. The results from IR and TGA show that the chemical structures for SNF and AP-P4 don’t basically change during the degradation. (2) Glycoluril and tetramethylol acetylenediurea were synthesized and can be used as viscosity stabilizer. The chemical structure and stability of glycoluril and tetramethylol acetylenediurea were studied by 1HNMR, dynamic laser light scattering, viscosity and viscoelasticity and so on. Glycoluril and tetramethylol acetylenediurea can be used as viscosity stabilizers for AP-P4. The results showed that glycoluril and tetramethylol acetylenediurea can obviously increase the viscosity of the system for AP-P4, in which glycoluril is better than tetramethylol acetylenediurea. Glycoluril can be used as viscosity stabilizer for SNF and can better increase the viscosity of the system for SNF.(3) The polymeric surfactant with quaternary ammonium salt (PQ) was synthesized by cationic ring open polymerization using boron trifluoride diethyletherate as cationic catalyst. The chemical structure and aggregation behavior of polymeric surfactant PQ were studied by 1HNMR, surface tension, static light scattering, dynamic laser light scattering, electrical conductivity and fluorescence measurement. In addition, PQ can be used as viscosity stabilizer, and the viscosity stability results from between flooding polymer (SNF) and PQ also suggest that the mixed system can greatly improve salt resistance and thermal stability and has the high practical application performance.
【Key words】 flooding polymer; viscosity stabilizer; degradation; polymeric surfactant;