井下稠油掺稀工具模拟与优化

发布时间：2018-04-13 17:39

本文选题：稠油掺稀 + 混合器　；参考：《东北石油大学》2017年硕士论文

【摘要】：稠油是石油能源的重要组成部分,因此众多学者对稠油开采的研究也从未间断。稠油最重要的一个特点就是粘稠度高,可流动性差。稠油对温度的敏感性很强,在地层中温度较高时稠油可以较好的流动,但在开采过程中,一旦流体进入井筒,随着温度的降低稠油粘度就会升高,摩擦阻力增大,抽油机悬点载荷增加,严重情况下导致抽油泵卡泵,甚至抽油杆断杆现象。而目前针对这一问题常采用的办法就是稠油掺稀、化学降粘和加热降粘。稠油掺稀是一种重要的降粘工艺,在我国西北地区得到广泛应用。长期以来,稠油掺稀的主要问题就是由于掺稀后不明确井筒内的状况,盲目增大掺稀比,从而造成了掺稀量的增大,造成了资源的浪费。本文利用数值模拟软件对掺稀过程中几个常见的过程及问题进行了模拟与分析,为稠油掺稀提供一定的理论依据。结合稠油掺稀的过程对Fluent的多相流模型和湍流模型进行了选择,经过筛选选用Mixture作为多相流模型,RNG k-e模型作为湍流模型。通过对光滑管的模拟显示,单纯光滑管掺稀起到的作用仅仅是在油管壁面形成一层稀油膜,降低原油流动的阻力,减小了抽油杆的载荷,并不能真正的达到掺稀降粘的效果;增大掺稀比不能增强掺稀效果,必须借助一定的搅动效果才能实现稠油掺稀;其它相存在的情况下,气体对掺稀效果具有增强作用,水降低了掺稀效果。SK型和SD型混合器都能很好的起到搅动和掺稀的效果,为实现混合器效果达到最优SK型在设计时长宽比尽量控制在5:3左右,且混合器的宽度要略小于油管尺寸;对于SD型混合器角度采用较小角度时效果最佳;就掺稀效果而言,SD型混合器优于SK型混合器;当掺稀量能够满足要达到的粘度值时,且通过混合器掺稀时没有必要增大掺稀比。针对SK型混合器进行了改进,并对改进结构进行了模拟。模拟结果显示,改进结构能够更好的实现掺稀。
[Abstract]:Heavy oil is an important part of petroleum energy.One of the most important characteristics of heavy oil is its high viscosity and poor fluidity.Heavy oil is very sensitive to temperature, and heavy oil can flow better when the temperature is high in the formation. However, once the fluid enters the wellbore, the viscosity of heavy oil will increase with the decrease of temperature, and the friction resistance will increase.The increase of suspension load of pumping unit leads to sucker pump jam, even sucker rod breaking.At present, the methods used to solve this problem are heavy oil blending, chemical viscosity reduction and heating viscosity reduction.Heavy oil blending is an important viscosity reduction process, which is widely used in northwest China.For a long time, the main problem of heavy oil mixing with dilute is that because the condition in wellbore is not clear after mixing dilute, the ratio of mixing dilute is increased blindly, which results in the increase of the amount of dilute and the waste of resources.In this paper, numerical simulation software is used to simulate and analyze several common processes and problems in the process of mixing heavy oil with dilute oil, which provides a certain theoretical basis for the mixing of heavy oil with dilute oil.The multiphase flow model and turbulence model of Fluent were selected according to the mixing process of heavy oil. Mixture was selected as the multiphase flow model and RNG k-e model was selected as turbulence model.The simulation of smooth tube shows that the function of pure smooth pipe is to form a thin oil film on the wall of oil pipe, reduce the resistance of crude oil flow, reduce the load of sucker rod, and can not really achieve the effect of adding thin oil to reduce viscosity;The mixing effect of heavy oil must be enhanced by increasing the blending ratio, and the gas can enhance the mixing effect of heavy oil in the presence of other phases.Water reduces the mixing effect. Both SK and SD mixers have good stirring and thinning effects. In order to achieve the optimal effect of SK type mixer, the aspect ratio of SK type is controlled at about 5:3 in the design as far as possible.And the width of mixer is slightly smaller than the size of tubing; the best effect is when the angle of SD mixer is smaller; the mixing effect of SD mixer is better than that of SK mixer in terms of dilute effect; when the amount of dilute can satisfy the viscosity value to be achieved,And it is not necessary to increase the dilution ratio when mixing through mixer.The SK mixer is improved and the improved structure is simulated.Simulation results show that the improved structure can better achieve thinning.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE345

【参考文献】