特种油气藏 ›› 2021, Vol. 28 ›› Issue (2): 156-162.DOI: 10.3969/j.issn.1006-6535.2021.02.024

• 钻采工程 • 上一篇    下一篇

椭圆井眼同心环空赫巴流体流动规律研究及压降计算简化模型

张洁1, 汤明2, 蒋振新1, 甘一风1, 曾德智2   

  1. 1.中国石油新疆油田分公司,新疆 克拉玛依 834000;
    2.西南石油大学,四川 成都 610500
  • 收稿日期:2020-08-14 修回日期:2020-12-25 出版日期:2021-04-25 发布日期:2022-02-16
  • 通讯作者: 汤明(1985—),男,副教授,2008年毕业于西南石油大学石油工程专业,2016年毕业于该校油气井工程专业,获博士学位,现从事井控和井壁稳定等方面的科研与教学工作。
  • 作者简介:张洁(1990—),女,工程师,2013年毕业于重庆科技学院石油工程专业,2016年毕业于西安石油大学油气田开发工程专业,获硕士学位,现从事钻井工艺方面的研究工作。
  • 基金资助:
    国家自然科学基金“基于水化进程的泥岩地层井壁坍塌机理研究”(51904260);中国石油重大工程技术现场试验项目“准噶尔南缘和玛湖等重点地区优快钻完井技术集成与试验”(2019F-33)

Study on Flow Rules of Herschel-Bulkley Fluid in Concentric Annulus of Elliptical Wellbore and Simplified Model for Pressure Drop Calculation

Zhang Jie1, Tang Ming2, Jiang Zhenxin1, Gan Yifeng1, Zeng Dezhi2   

  1. 1. PetroChina Xinjiang Oilfield Company, Karamay, Xinjiang 834000, China;
    2. Southwest Petroleum University, Chengdu, Sichuan 610500, China
  • Received:2020-08-14 Revised:2020-12-25 Online:2021-04-25 Published:2022-02-16

摘要: 因岩石和地应力的非均匀性易形成椭圆井眼,导致现有规则圆形井眼环空流动模型存在较大误差。为明确椭圆井眼同心环空赫巴流体流动规律,建立了解析模型和Fluent仿真模型,分析椭圆井眼对环空流速和压降梯度的影响规律;通过修正水力直径和引入有效黏度的方法建立了椭圆井眼同心环空压降计算简化模型,实现流动压降的准确快速预测,并利用解析模型、仿真模型和实测结果对简化模型有效性进行验证。结果表明:当流量一定时,轴向平均流速和最大流速随椭圆长短轴轴长比值的增大呈线性和指数型增加;无量纲压降梯度随椭圆长短轴轴长比值增大呈线性增加;简化模型与仿真模型、解析模型和实测结果均吻合较好,误差分别为±8%、±5%和±5%。研究成果为椭圆井眼同心环空流动压降准确快速预测提供了理论支撑。

关键词: 压力预测, 椭圆井眼, 同心环空, 赫巴流体, 层流流动, 环空压降

Abstract: The wellbore is easy to become elliptical due to the uneven rocks and in-situ stress, leading to great deviation in the existing annulus flow model of regular circular wellbore. In order to identify the flow rules of Herschel-Bulkley fluid in the concentric annulus of the elliptical .wellbore, an analytical model and a Fluent simulation model were established to analyze the influence of the elliptical .wellbore on the annulus flow velocity and pressure drop gradient. A simplified model was established for pressure drop calculation of concentric annulus of elliptical wellbore by correcting the hydraulic diameter and introducing effective viscosity to realize accurate and rapid prediction of flow pressure drop. The effectiveness of the simplified model was verified by the analytical model, simulation model and measured results. The results showed that when the flow rate was constant, the axial average velocity and maximum velocity increased linearly and exponentially with the increase of the ratio of the long and short axis of the ellipse; the dimensionless pressure drop gradient increased linearly with the increase of the ratio of the long and short axis of the ellipse; the simplified model was well fitted with the simulation model, analytical model and measured results, and the deviations were ±8%, ±5% and ±5%, respectively. The study results can be used as a theoretical support for accurate and rapid prediction of flow pressure drop in concentric annulus in elliptical wellbore.

Key words: pressure prediction, elliptical wellbore, concentric annulus, Herschel-Bulkley fluid, reservoir fluid flow, annulus pressure drop

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