不规则井眼环空流体流动压降计算方法  

Calculation method for pressure drop of annular fluid flow in irregular boreholes

作　　者：杨晨 肖志海 刘涛 YANG Chen;XIAO Zhihai;LIU Tao(Changqing Cementing Company of Chuanqing Drilling Engineering Co.,Ltd.,PetroChina,Xi’an,Shaanxi 710065,China;School of Petroleum Engineering,Yangtze University,Wuhan,Hubei 430100,China)

机构地区：[1]中国石油川庆钻探工程有限公司长庆固井公司,陕西西安710065 [2]长江大学石油工程学院,湖北武汉430100

出　　处：《石油地质与工程》2023年第2期107-111,共5页Petroleum Geology and Engineering

基　　金：国家自然科学基金“不规则井眼固井环空流场及井壁附着泥浆滞留机理研究”(51804043)。

摘　　要：对于窄密度窗口地层,精确计算与固井环空压力对于保障施工安全和固井质量十分重要。在实际钻井过程中,井径扩大率不均匀容易形成“大肚子”不规则凹面井眼,针对不规则凹面井眼段的流体流动压降计算方法进行研究有助于精准控制环空压力剖面。结合实钻井眼情况建立了不规则凹面井眼条件下的流体流动连续性方程和动量守恒方程,并研究确定了求解方法与求解流程,开发了不规则凹面井眼流动计算分析软件,计算了不规则凹面井眼条件下的流体流动压降,分析了井径扩大率和流体排量对流动压降的影响规律,为固井环空压力剖面的精细计算提供了技术参考。For the formation with narrow density window,a precise calculation and control of cementing annulus pressure is important.During the actual drilling process,an irregular borehole with"big belly"is easily formed due to the uneven enlargement of the hole diameter.The research on the calculation method of fluid flow pressure drop in the irregular borehole section will help to control the annular pressure profile.The fluid flow continuity equation and momentum conservation equation under the condition of irregular borehole are established in combination with the actual drilling situation,and the solution method and flow are studied and determined.The flow calculation and analysis software for irregular borehole is developed,and the fluid flow pressure drop under the condition of irregular borehole is calculated,and the influence of well diameter expansion rate and fluid displacement on the flow pressure drop is analyzed,which provides a technical reference for precise calculation of cementing annulus pressure profile.

关 键 词：不规则井眼 连续性方程 动量守恒方程 交错网格 压降计算 

分 类 号：TE256[石油与天然气工程—油气井工程]