核磁共振技术在油气储层润湿性评价中的应用综述

Reservoir Wettability Evaluation Using Nuclear Magnetic Resonance Technology

油气藏储层润湿性是影响油水微观分布、毛管力、相对渗透率及束缚水饱和度等的关键因素之一,润湿性测定也是岩心专项分析的重点研究内容之一。准确评价储层岩石润湿性特征对于制定合理的开发方案及优选提高采收率措施具有极为重要的基础指导作用。在简要介绍3种经典润湿性评价方法及自吸速率法评价储层润湿性方法的基础上,通过对大量文献的综合调研分析,综述了使用核磁共振技术评价储层岩石润湿性的发展历史、研究成果及应用现状等内容。结合多孔介质多相流体相互作用机制,分析了核磁共振技术定量评价储层润湿性的基本原理、适应性及优缺点,指出了目前研究的局限性及需要进一步研究的内容。

Wettability is one of the most important factors affecting micro-distribution of water and oil in rock pore space, capillary pressure, relative permeability, and irreducible water saturation. Wettability measurement is one of key research branches in special core analysis. It is very useful to develop the best development strategy and select an optimal EOR method on the basis of accurate known wettability of target petroleum reservoir. The three classical wettability evaluation methods and their disadvantages are briefly introduced. The development history, research results, and applications are reviewed through the investigation into a large number of professional literatures. Meanwhile, the basic mechanism, accuracy, and advantages are also analyzed with the multiphase fluid flow theory in wettability evaluation using Nuclear Magnetic Resonance （NMR）.