摘要
CO2驱正越来越受到重视,然而对高含CO2原油混合体系的井筒流动问题,目前尚未见到相关研究文献。由于井筒中CO2从原油中大量脱出,将会对井筒温度压力分布产生较大影响,严重时甚至会发生井喷,因此,对此类问题的研究具有重要的现实意义。从传热学、两相流及多元气液平衡理论出发,将CO2/原油混合流体相态特征以及井筒温度、压力相互影响加以考虑,建立了高含CO2原油井筒流动压力、温度分布综合计算模型,对不同CO2摩尔分数的原油混合体系井筒流动温度、压力进行了计算,结果表明,随着混合体系中CO2含量的增加,井口流体温度呈下降趋势,而井口压力将会增加,在一定条件下油井甚至能够达到自喷。对实例井进行了计算,模型计算结果与实测结果吻合较好,为CO2驱采油井工程设计提供理论方法。
With the requirements of greenhouse gas emission reduction, more importance has been attached to CO2 flooding. However, current research literatures of oil with high CO2 flows in welbore, have not been found. Temperature and pressure distribution will have a significant impact, when CO2 is separated from crude oil in wellbore. Furthermore blowout even occurs in serious situation. Consequently, it is important to study on this problem. Based on the theories of heat transfer, two-phase flow and gas-liquid equilibrium, a pressure-temperature coupling calculation model is developed in this paper. The CO/oil mixed phase characteristics and the interaction of temperature and pressure in wellbore have been taken into account in the model. An example has been calculation using the model in this paper. Comparisons of field testing data and computed data of pressure and temperature indicate that calculation results are in good agreement with the measured results. The pressure and temperature of the oil with high CO2 mixed system flow in wellbore are calculated using the model under different CO2 content in the system. The results show that with the increase in CO2 content in the mixed system, wellhead fluid temperature declines and the pressure increases. Even in some conditions the producer can achieve flowing. The research results indicate that the model developed in this paper is valid. It will provide a theoretical method for the engineering design of the production wells in CO2 flooding.
出处
《石油钻采工艺》
CAS
CSCD
北大核心
2010年第1期65-69,共5页
Oil Drilling & Production Technology
基金
国家863项目"二氧化碳驱油提高石油采收率与封存关键技术研究"和中国石油科技创新基金(编号:2008D-5006-02-07)联合资助
