摘要
针对煤层气井存在套管不居中和井眼不规则的情况,建立煤层气井偏心环空不规则井眼简化模型,定义顶替接触界面协调性描述方法,应用计算流体力学(computational fluid dynamics,CFD)方法选择流体体积(volume of fluid,VOF)模型对赫巴模式注水泥顶替过程进行控制和求解。结果表明:水泥浆偏心流动上端突进、下端滞后,重力效应对其有一定的抑制作用;顶替流体相对密度与套管偏心度存在最优耦合条件,适当增大顶替流体相对密度有助于改善偏心环空顶替效果;井眼突变产生漩涡流和“顶替死角”,顶替效果随井眼不规则性增强加速下降。因此,改善套管居中度、保证井眼连续性是提高顶替效果的重要措施。
Aiming at the case of casing misalignment and borehole irregularity in coalbed methane wells,a simplified model of irregular wellbore in eccentric annulus of coalbed methane wells was established,and a description method of the coordination of displacement contact interface was defined.The volume of fluid(VOF)model was selected by computational fluid dynamics(CFD)method.The Heba model cement replacement process was controlled and solved.The results of the study show that the eccentric flow of cement slurry advances at the upper end and lags at the lower end,and the gravity effect has a certain inhibitory effect on it;there is an optimal coupling condition between relative density of the displacement fluid and eccentricity of the casing,appropriately increasing the relative density of the displacement fluid helps to improve the displacement effect of the eccentric annulus;the sudden change of the wellbore produces vortex flow and“displacement dead angle”,and the displacement effect accelerates and decreases with the increase of borehole irregularity.Therefore,improving casing centering and ensuring borehole continuity are important measures to improve the displacement effect.
作者
杨加伟
熊青山
吴胜
李成龙
YANG Jiawei;XIONG Qingshan;WU Sheng;LI Chenglong(School of Petroleum Engineering, Yangtze University, Wuhan 430100, China)
出处
《中国科技论文》
CAS
北大核心
2022年第5期502-507,共6页
China Sciencepaper
基金
国家科技重大专项(2016ZX05043,2016ZX05025-004-003)。
关键词
煤层气井
偏心环空
注水泥顶替
接触界面
重力效应
计算流体力学
coalbed methane wells
eccentric annulus
cement injection displacement
contact interface
gravity effect
computational fluid dynamics(CFD)
