稠油掺气输送阻力特性研究

发布时间：2018-05-17 07:26

本文选题：气液混输 + 稠油　；参考：《西南石油大学》2017年硕士论文

【摘要】：稠油作为一种重要的能源,在石油天然气勘探开发以及国家能源战略储备中占有重要的地位。由于稠油黏度高、密度大,且流动性差,常规输送工艺难以满足其安全经济高效的管输要求。受流体掺气减阻的启发,同时考虑到一些偏远分散油井及海洋平台多将伴生气放空或燃烧处理,若将这些气体与稠油混输,可望实现稠油的减阻节能输送。为此,论文提出稠油掺气阻力特性研究的思路及方法,探讨稠油掺气减阻的条件及主要影响因素,探索稠油管输减阻的新方法,为促进稠油掺气输送技术发展奠定理论基础。论文采用数值模拟与室内实验相结合的研究手段,对稠油掺气输送阻力特性以及相关问题开展深入研究:采用数值模拟方法,通过建立海管模型,研究了掺气介质、气液比和管径对压降、温降、气液相流速、持液率和流型的影响;采用220#白油、440#白油作为模拟用油,测试并分析其物性、特性的变化规律;选择空气作为实验模拟掺气介质,设计合适的掺气系统,建立小型实验环道装置模拟稠油掺气输送,系统研究了稠油掺气过程中的流动行为,探讨了其流动过程中的掺气压降、流型等变化规律;对比分析相关压降模型描述稠油掺气流动实验的适用性。研究结果表明:(1)稠油随掺气量的增加,沿程压降均逐渐增大,持液率逐渐降低,并逐步出现段塞流;掺气介质为伴生气时压降最小,为二氧化碳时最大;通过掺气压降值的相对大小比对,不断缩小各掺气介质的最优掺气区间,在模拟区间内得到氮气和空气的最优掺气比均为为1:1,二氧化碳的最优掺气比为0.65:1,伴生气的最优掺气比为1.2:1;(2)220#和440#模拟油在测试温度10～60℃下均具有良好的牛顿流体特性,并且在10～30℃下黏度随温度的升高而降低明显;(3)实验范围内220#白油掺气减阻率大多在20%以下,最大减阻率不超过60%,且采用T型三通掺气方式的减阻率总体高于采用Y型三通掺气方式的获得的减阻率;在同一种掺气方式下,440#白油与220#白油相比,整体减阻率更高,在相同的减阻率下气液比更高,但低气液比减阻效果更好;(4)在实验工况下,220#白油T型掺气在气液比为24.02时减阻率最大,为49.24%;Y型掺气时在气液比为4.35时减阻率最大,为39.13%;440#白油Y型掺气在气液比为0.96时减阻率最大,为33.76%。同时,由第2章的模拟结果可知,在软件模拟工况范围内,掺入空气的最优掺气比为1:1,稠油黏度亦与本章模拟油黏度相近,说明液相黏度是影响最优掺气比的主要因素之一;(5)理论计算值主要分布在较低的压降区间,而实验值主要分布在较高的压降区间;当流体的黏度一定时,其数据点主要分布在低气液比范围内,气液比数值越小,计算的压差值与模拟结果之间的误差越小,黏度越高模型的适用性越差;(6)杜克勒Ⅱ法更适合描述文中流体掺气流动过程,同时也验证了杜克勒Ⅱ法压降公式适用的黏度范围和流量范围较杜克勒I法更广。
[Abstract]:Heavy oil, as an important source of energy, occupies an important position in oil and gas exploration and development and national energy strategic reserve. Due to the high viscosity, large density and poor fluidity of heavy oil, it is difficult to meet the safe and efficient pipeline transportation requirements by conventional transport technology. In oil wells and offshore platforms, most of the associated gas is released or burned. If these gases are mixed with heavy oil, it is expected to realize the energy saving and energy saving transportation of heavy oil. Therefore, the paper puts forward the thought and method for the study of the resistance characteristics of heavy oil, discusses the conditions and main influencing factors of the drag reduction of heavy oil, and explores a new method to reduce the resistance of heavy oil pipes. The theoretical foundation for the development of heavy oil aeration transport technology is laid. In this paper, numerical simulation and laboratory experiments are used to carry out a thorough study on the resistance characteristics and related problems of heavy oil aeration transport. By using the numerical simulation method and through the establishment of the sea pipe model, the air and liquid ratio and the pipe diameter are studied for the pressure drop, temperature drop and gas and liquid. The effect of phase flow rate, liquid holdup and flow pattern, using 220# white oil and 440# white oil as simulated oil, test and analyze its property and characteristics, choose air as an experimental analog aeration medium, design a suitable aeration system, establish a small experimental loop device to simulate heavy oil aeration transport, and systematically study the flow of heavy oil in the process of aeration. Dynamic behavior, the variation law of air pressure drop and flow pattern in the flow process is discussed, and the applicability of the correlation pressure drop model is compared and analyzed. The results show that (1) the pressure drop along the range increases gradually with the increase of the amount of gas, the liquid holding rate decreases gradually, and the slug flow gradually appears, and the aeration medium is associated gas. The minimum time pressure drop is the maximum of carbon dioxide; the optimum aeration interval of each aeration medium is narrowed by the relative size ratio of the air pressure drop. The optimum aeration ratio of nitrogen and air is 1:1, the optimum aeration ratio of carbon dioxide is 0.65:1, and the optimal aeration ratio of associated gas is 1.2:1 in the simulated interval; (2) 220# and 440# simulation The oil has good Newton fluid characteristics at the test temperature of 10~60 C, and the viscosity decreases with the increase of temperature at 10~30 C. (3) the drag reduction rate of 220# white oil is mostly below 20% and the maximum drag reduction rate is not more than 60% within the experimental range, and the drag reduction rate of T type three through aeration is generally higher than that of Y type three. In the same aeration mode, the overall drag reduction rate of 440# white oil is higher than that of 220# white oil, and the gas to liquid ratio is higher at the same drag reduction rate, but the low gas solution is better than the drag reduction effect. (4) under the experimental conditions, the maximum drag reduction rate of 220# white oil T aeration is 49.24% when the gas to liquid ratio is 24.02, and the Y type aeration is in the gas to liquid ratio when the Y type aeration is used. The maximum drag reduction rate at 4.35 is 39.13%, and the maximum drag reduction rate of 440# white oil Y aeration is 33.76%. at the gas liquid ratio of 0.96. The simulation results of the second chapters show that the optimal mixture ratio of air is 1:1, and the viscosity of heavy oil is similar to that of this chapter, indicating that the viscosity of liquid is the optimal mixture ratio. One of the main factors: (5) the theoretical calculation is mainly distributed in the lower pressure drop interval, and the experimental value is mainly distributed in the higher pressure drop interval. When the viscosity of the fluid is fixed, the data point is mainly distributed in the range of low gas liquid ratio, the smaller the gas liquid ratio, the smaller the error between the calculated pressure difference and the simulation result, the higher the viscosity model. The worse the applicability is, (6) the Duke Le II method is more suitable for describing the flow of fluid aeration in the paper, and it is also proved that the range of viscosity and flow range of the Duke Le II pressure drop formula is more wide than that of the Duke I method.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE832

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