摘要
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。
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 will interact with each other in coal-bed methane reservoirs. But the recovery process by gas injection cannot be effectively simulated by conventional two-phase flow equations. So Coal-bed methane muhicomponent flow equations are required in the complex process. During the course of recovery by gas injection, gas component will appear and disappear. When the nonexistent gas components in reservoirs are injected, the new components will appear. 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 a-dimension, two-phase, full implicit procedure, multi-component flow model.
出处
《天然气地球科学》
EI
CAS
CSCD
2007年第4期580-583,共4页
Natural Gas Geoscience
基金
国家"973"煤层气项目"煤层气经济开采增产机理研究"(编号:2002CB211709)资助
关键词
煤层气
扩散
数学模型
数值模型
注气
流动模型
吸附-解吸
Coalbed methane
Mathematical model
Numerical simulation
Gas injection
Flow model Adsorption/desorption.
