微裂缝气体流动机理的格子Boltzmann研究  

Lattice Boltzmann Simulations of the Flow Mechanism of Gas in Micro-fracture

作　　者：朱益华[1,2] 陶果[2] 方伟 

机构地区：[1]中国石油集团测井有限公司技术中心,陕西西安710021 [2]中国石油大学油气资源与探测国家重点实验室,北京102249 [3]中国石油长城钻探工程有限公司解释研究中心,北京100101

出　　处：《测井技术》2010年第3期223-226,共4页Well Logging Technology

基　　金：国家自然科学基金资助项目(50374048);国家973基础研究项目(2007CB209601)

摘　　要：研究了低渗透率气藏中气体的流动规律。介绍了格子Boltzmann方法原理。讨论微裂缝中的滑动流动状态,从微观角度用LBM研究基于滑移边界条件的低渗透率气藏微裂缝气体流动机理,并对开度为2μm的微裂缝模型进行模拟研究。将反弹边界处理和自由滑移边界处理相结合,较准确地反映了气体与固体之间的相互作用。认为二维平板微裂缝中稀薄气体流动,不仅与通道高度、压力梯度和黏度有关,而且与Knudsen数和切向动量调和系数σv相关。从氢气、氮气、氦气的模拟结果看,气体滑脱效应与气体性质有关;微裂缝开度越小,滑脱效应越严重。用LBM方法进行模拟的结果与解析解吻合得很好,从而验证了LBM方法研究微裂缝气体流动机理的正确性。Studied are the gas flow rules in low permeability reservoir. Introduced are the principles of Lattice Boltzmann Method （LBM）. By discussing the slippage condition in micro-fracture, LBM was used to study the flow mechanism of gas flowing in the micro fracture in low permeabil ity reservoir at the micro scale based on the slide boundary condition. Simulation for 2μm opening micro-fracture model is carried out. It precisely reflects the interaction between gas and solid by combining rebound boundary processing and free slippage boundary processing. It is believed that, thin gas flow in two dimensional plane micro fracture is not only related to channel height, pressure gradient and viscosity, but also related to Knudsen constant and tangential momentum factor σv- According to simulated results of hydrogen, nitrogen and helium, gas slippage effects concern with gas properties. The smaller the fracture opening, the worse the gas slippage effects. The LBM simulation result is approximately consistent with analytic solution. It proves the validity of the LBM method in studying gas flow mechanism of micro-fracture.

关 键 词：低渗透率气藏 微裂缝 格子BOLTZMANN方法 流动机理 滑移边界条件 

分 类 号：P631.84[天文地球—地质矿产勘探]