基于赫巴流体的偏心环空波动压力数值模拟  

Herschel-Buckley Fluid-based Numerical Simulation of Eccentric Annular Fluctuating Pressure

作　　者：郭宇健[1] 李根生[1] 宋先知[1] 田守嶒[1] 王梦抒[1] 

机构地区：[1]中国石油大学(北京)油气资源与探测国家重点实验室

出　　处：《石油机械》2014年第3期5-9,共5页China Petroleum Machinery

基　　金：国家973计划项目"深井复杂地层安全高效钻井基础研究"(2010CB226704)

摘　　要：基于牛顿流体、幂律流体以及卡森流体建立的偏心环空稳态波动压力预测模型计算过程对计算机的硬件要求较高,在现场条件下并不适用。为此,基于钻井液赫巴流变模式,利用Fluent软件对起下钻波动压力进行了计算,并将计算结果与现场广泛应用的压力模型及室内试验数据进行了对比验证。建模时采用一阶迎风格式对动量方程的对流项进行离散,壁面设为非滑移壁面。分析结果表明,数值模拟结果与现存的同心环空计算模型及同心、偏心室内试验结果具有很高的一致性,最大误差不超过8%;流动指数、钻柱井筒直径比以及钻柱偏心度对波动压力影响较大,在窄间隙工况或具有高流动指数流体的情况下应严格控制起下钻速度。The calculation process of the eccentric annular steady state fluctuating pressure model based on Newtonian fluid, powerlaw fluid and Casson fluid requires a high quality of computer hardware and thus it cannot be applied to field operations. Therefore, on the basis of the Herschel-Buckle rheologieal mode, the Fluent software was used to conduct a calculation of the fluctuating pressure in tripping. A comparative verification of the calculation result, the pressure model of extensive field application and laboratory test data was carried out. In modeling, the first-order upwind scheme was adopted to conduct the discretization of the convective term of momentum equa- tion. The wall surface was designed as the non-slip surface. The analysis shows that the numerical simulation result is very well in agreement with the concentric annular calculation model and the concentric and eccentric laboratory test findings. The maximum error is less than 8%. The effects of flow index, drill string and shaft diameter ratio and drill string eccentricity on fluctuating pressure are considerable. The tripping velocity should be controlled strictly in the narrow-gap operating condition or with respect to high flow index fluid.

关 键 词：赫巴流体 波动压力 偏心环空 等效速度 流动指数 偏心度 

分 类 号：TE242[石油与天然气工程—油气井工程]