中国稠油热采开发技术与发展方向

Development technology and direction of thermal recovery of heavy oil in China

稠油是重要的石油资源类型,实现稠油资源持续、高效开发,对保障国家能源安全具有重要的现实意义。针对中国热采稠油的主要特征进行了分析和总结:在地质和油藏特征方面,中国稠油油藏类型多、埋藏深、油层薄、储层非均质严重、油水系统复杂;在组成特征方面,胶质和沥青质分子之间相互作用形成空间网状结构导致稠油黏度大;在流变特性方面,稠油存在临界温度,当温度大于临界温度时,稠油流变行为呈现牛顿流体流变特性,当温度小于临界温度时,稠油流变行为呈现具有屈服值的宾汉流体特征;在渗流特征方面,稠油在地下渗流呈现非达西渗流特征,存在启动压力梯度,其受温度、储层渗透率、地层原油黏度及沥青质含量影响。综述了国内外稠油开发技术现状,详细阐述了蒸汽吞吐、蒸汽驱、蒸汽辅助重力泄油(SAGD)、火烧油层、热复合开发等技术的主要机理、适用条件、应用实例、存在问题和发展方向,蒸汽吞吐仍是稠油热采的主要方式,蒸汽驱是蒸汽吞吐后有效接替技术之一,SAGD技术在引进吸收中取得重要进展,火烧油层成为大幅度提高采收率的重要技术,热复合开发技术实现难采稠油高效开发。研究结果表明,未来稠油开发需要发展高质高效的热力开发技术,协同采收率和油汽比"双目标"最大化,持续加强油藏描述、动态监测和注采调控,积极探索产热方式转变,从而实现稠油效益开发和绿色低碳发展。

Heavy oil is an important type of oil resources.Sustainable and efficient development of heavy oil resources have great significance to national energy security.The main characteristics of thermal recovery of heavy oil in China are summarized as below:as viewed from geological and oil-reservoir characteristics,China boasts various types of heavy oil reservoirs with deep burial,thin bed,strong heterogeneity and complex oil-water system;as for composition,the spatial reticular structure formed from the interaction between colloid and asphaltene molecules leads to high viscosity of heavy oil;as for rheological properties,there is a critical temperature.When the temperature is higher than the critical temperature,heavy oil displays the properties of Newtonian fluids;when the temperature is lower than the critical temperature,heavy oil displays the rheological properties of Bingham fluids with yield value;as for percolation characteristics,heavy oil possesses the properties of underground non-Darcy flow,with a starting pressure gradient,and it is subject to the influences of temperature,reservoir permeability,crude oil viscosity and asphaltene content.This paper summarizes the status quo of heavy oil development technology at home and abroad,and elaborates the main mechanism,applicable conditions,application examples,current problems and development direction of steam huff and puff,steam flooding,steam assisted gravity drainage(SAGD),in situ combustion and thermal composite development.Steam huff and puff is still the main method for thermal recovery of heavy oil and steam flooding is one of the effective substituted techniques to steam huff and puff;SAGD has made important progress in technology introduction and absorption;in situ combustion has become an important technology of greatly improving recovery efficiency;thermal composite development technology has realized efficient production of the marginal heavy oil.It is indicated that heavy oil requires high-quality and efficient thermal recovery technology in the future.In line with the maximization of"double objectives"for recovery efficiency and oil steam ratio,it is required to continuously strengthen reservoir description,dynamic monitoring and injection-production regulation,and actively explore the transformation of heat generation mode,so as to realize efficient development of heavy oil and green low-carbon development.