稠油出砂冷采数学模型研究

Modeling Cold Heavy Oil Production with Sand

随着世界经济快速发展和对石油需求的不断增长,具有巨大勘探潜力和广阔发展前景的重油成为21世纪重要的能源资源之一,全球稠油储量目前达到6万亿桶。稠油出砂冷采(CHOPS)是重油生产的重要方法之一,该技术可以避免热采时油层出砂、气窜和采油成本高的问题。因此,对稠油出砂冷采技术进行相关研究,具有重要的战略意义。在对CHOPS的蚯蚓洞生长和泡沫油流两个主要机制进行比较的基础上,提出了耦合地质力学和流体力学的稠油出砂冷采模型。为了验证模型的可靠性和实用性,使用油田实际数据对模型进行验证,分析了对CHOPS技术应用影响较大的几个参数,进一步确定了该技术的应用范围。最后分析了模型的优缺点,提出了模型今后的发展方向,确定了下一步的研究重点。

Heavy oil is the most important resource to supplement the loss of oil in the 21st century. The International Energy Agency （lEA） estimates that there are 6 trillion barrels of heavy oil worldwide. Currently, the standard heavy oil production is based on steam injection, which faces a great challenge because of the sand production, gas channelling, and high costs. Cold Heavy Oil Production with Sand （CHOPS） has extremely good primary performance, high oil production rates, high primary recovery factors, and low operational costs. In this paper, the mathematical and numerical descriptions are given for the sand production within the context of continuum mechanics and finite dements, with emphasis on the physics of the sand production and its relation to the interaction between hydrodynamics and geomechanics. A mathematical model is proposed based on the erosion mechanics, while the instability associated with the sand production is treated within the framework of the high gradient continuum mixture theory. Numerical results of the proposed model are in good agreement with the oil field data, which shows that the model could be applied to predict the oil production and to provide a guidance to adjust the explore strategy. Moreover, the influencing factors, such as oil viscosity, producing pressure drop and information coefficient on CHOPS performances are discussed, which helps to determine what kind of reservoir is relevant for the application of the CHOPS. At last, the advantages and disadvantages of the model are discussed in detail and the future work of modeling cold production is commented.