中国煤层气具有低压、低渗和低饱和的特点,采用常规技术开发效果不理想,注气增产法可使采收率达到90%以上,单井产量提高5倍以上,是一种具有发展前途的增产技术。指出注气后煤层中存在多元气体的相互作用,用常规的二相流动方程不能有效地模拟煤层气注气(N2,CO2)开采过程,这个过程需要煤层气多组分流动方程来描述;在注气驱替过程中还会发生新气体组分的出现和原有组分消失,当注入储层中不存在的气体组分时,新的气体组分就会出现,原先存在于煤层中的某些气体组分可能被完全分离出来而消失。在研究煤层气渗流机理的基础上并考虑这些因素,建立了一个注气驱替煤层气的三维、两相、双孔、全隐式、多组分流动模型。 更多还原

In China, most of coal-bed methane reservoirs are characterized by their low pressure, low permeability and low saturation. There is no ideal exploitation by using techniques of conventional stimulations and pressure-deceasing recovery. The technique of enhanced coal-bed methane recovery by gas injection is a burgeoning enhanced recovery technique. It can make recovery ratio reach over 90 percent, and single well production increased by over five times. After gas injection, multi-element gases well interact with each oter in coal-bed methane reservoirs. Some gas components will be completely substituted and disappear. Fully considering these factors and combining these with recovery characters of gas injections, this paper builds a 3-dimension, two-phase, full implicit procedure, multi-component flow model.