摘要
煤层气–水段塞流动是制约煤层气井生产能力的重要因素,然而有关微尺度通道内两相段塞流动规律的研究较少。采用自主研发的微量流体注入–显微观测–微尺度模型试验系统开展气–水在不同湿润性、液速条件下的段塞流动试验,通过高速摄像机获取气–水微尺度相互作用形态,利用相场法分析段塞单元的压力分布,最终得到气–水段塞流动规律。结果表明:(1)段塞流状态下气–水界面的“阶跃压力”使气相流动能力显著降低,气相传导率在等流量注入时比单相流动低约3个数量级。(2)在两相段塞流动状态下,气相表观长度随着含水饱和度的增大呈负指数降低,气相相对渗透率随着含水饱和度的增大呈现强相关的负指数关系。(3)气塞引起的附加压力降是段塞流制约气–水流动的主要原因,压力降随着湿润性的增加而降低,气相渗透率在低含水饱和度时对湿润性的变化更为敏感。高液速产生了更大的惯性力,此时气相相对渗透率对含水饱和度变化的敏感性降低。该研究揭示了气–水两相在微尺度运移通道内段塞流状态的流动规律,为抑制段塞流、煤层气高效生产提供了理论基础。
Coalbed gas-water slug flow is an important factor limiting coalbed methane production,but there have been relatively few studies on the patterns of two-phase slug flow in microscale channels. In this study,an independently developed microfluid injection-microscopic observation-microscale modeling system was used to conduct gas-water slug flow experiments under different humidity and fluid velocity conditions. Slug flow patterns were determined using the pressure data and the gas-liquid interaction captured by high-speed cameras.The pressure distribution of three-dimensional slug units was analyzed using the phase-field method. The results shows:(1) “Step pressure” on the gas-liquid interface of slug flow leads to a significant decrease in gas flow capacity. Equal flow injection reduces the gas conductivity by about three orders of magnitude in comparison with single-phase flow.(2) In two-phase slug flow,the apparent length of the gas phase decreases exponentially as the water saturation increases,as does the relative permeability of the gas phase.(3) The additional pressure drop caused by the gas lock is the main restrictor of slug flow,and the pressure drop decreases as the hydrophilicity increases. The gas permeability is more sensitive to changes in wettability at low water saturation. High liquid velocity produces greater inertial force,which makes the relative permeability of the gas phase less sensitive to changes in water saturation. This study reveals the patterns of gas-water two-phase slug flow in microscale channels,and provides a theoretical basis for suppressing the occurrence of slug flow and promoting the efficient production of coalbed methane.
作者
陈绍杰
张继成
ZAKI M M
尹大伟
王升
盛守前
KHORESHOK A A
CHEN Shaojie;ZHANG Jicheng;ZAKI M M;YIN Dawei;WANG Sheng;SHENG Shouqian;KHORESHOK A A(College of Energy and Mining Engineering,Shandong University of Science and Technology,Qingdao,Shandong 266510,China;Faculty of Engineering,Al-Azhar University,Cairo 11884,Egypt;College of Mining Engineering,T.F.Gorbachev Kuzbass State Technical University,Kemerovo 650000,Russia)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2022年第7期1338-1346,共9页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(52174159,52074169)
国家自然科学基金青年基金资助项目(51904167)。
关键词
采矿工程
煤层气
微尺度
段塞流
附加毛细管力
导流能力
mining engineering
coalbed methane
microscale
slug flow
additional capillary force
conductivity capacity
