深水钻井隔水管力学特性与涡激振动研究

发布时间：2018-06-01 02:59

本文选题：深水钻井 + 隔水管　；参考：《西南石油大学》2016年硕士论文

【摘要】：深海油气资源勘探与开发已经逐步成为国内外油气工业发展的主趋向。海上钻井相对陆地钻井难度更大、花费更高,复杂、恶劣的深水环境对海洋石油钻井装备提出了更高的要求。深水钻井隔水管是连接海上钻井平台和海底井口装置的关键设备,起着隔离海水、形成钻井液循环通道的作用,并为钻具的下入和收回提供导向。随着海洋石油钻井作业水深的增加,隔水管的受力形式也因整体长度增长变得更加复杂,由波流作用导致的疲劳破坏问题日益突出,严重影响隔水管的国产化研究与应用。为此,本文开展了深水钻井隔水管力学特性与涡激振动研究,主要完成了以下几方面的研究工作：(1)完成了国内外钻井隔水管系统组成、环境载荷、工况参数、力学性能、涡激振动及其涡激振动抑制装置等研究资料的收集与分析,提出了本文的研究方案和思路。(2)分析了深水钻井隔水管单元力学模型,建立了平衡微分方程。通过OrcaFlex软件建立了1200m水深隔水管系统的分析模型,进行了隔水管静力与动力响应对比分析,为后文参数条件选取提供了理论依据。研究了隔水管壁厚、顶张力、钻井液密度等参数变化对隔水管固有频率的影响,为涡旋脱落频率的分析研究提供了对比依据,得到了涡激诱发振动是研究隔水管疲劳损坏的重要因素,为本文的研究指明了研究方向。(3)开展了深水钻井隔水管受环境因素和作业因素影响的参数敏感性分析,得到了不同因素变化对隔水管动态响应的作用规律。在此基础上,对关键性影响因素进行了多敏感性参数的正交分析,得到了各关键性因素对深水钻井隔水管系统刚度和强度的影响规律,为隔水管涡激振动及其抑制装置研究提供了理论依据。(4)利用Fluent软件建立了深水钻井隔水管二维绕流数值模型,研究了不同流速下隔水管的绕流流场特点、升阻力系数和涡旋脱落频率的变化规律,得到了涡激振动对隔水管不同深度下的影响情况,为隔水管涡激抑制装置的研究提供了理论依据。(5)研究设计了一种新型涡激抑制装置。在充分研究现有涡激抑制装置的基础上,结合涡激诱发振动机理设计了一种带弧形尾翼的涡激抑制装置,并进行了结构分析与优化,提高了新型涡激抑制装置的抑制效率,使该涡激抑制装置具有良好的工程应用价值及广阔的应用前景。总之,本文的研究工作对深水钻井隔水管的力学特性、涡激振动及涡激振动抑制装置研究提供了技术支持与理论指导,对隔水管设计和安全运行具有重要指导意义,将进一步推动深水钻井隔水管的国产化研究与工业应用。因此,本文的研究工作不仅具有重要的理论意义和学术价值,而且具有广泛的应用前景。
[Abstract]:Exploration and development of deep-sea oil and gas resources have gradually become the main trend of oil and gas industry development at home and abroad. Offshore drilling is more difficult, more expensive, more complex, and the bad deep-water environment has put forward higher requirements for offshore oil drilling equipment. Deep-water drilling riser is the key equipment to connect offshore drilling platform and undersea wellhead device. It plays the role of isolating seawater, forming drilling fluid circulation channel, and providing guidance for drilling tool entry and recovery. With the increase of water depth in offshore oil drilling operation, the stress form of riser becomes more complex because of the increase of integral length, and the fatigue failure caused by wave and current is becoming more and more serious, which seriously affects the domestic research and application of riser. In this paper, the mechanical characteristics and vortex-induced vibration of deepwater drilling riser have been studied. The following research work has been done: 1) the composition of drilling riser system at home and abroad, environmental load, operating condition parameters, mechanical properties, etc. Based on the collection and analysis of the research data of vortex-induced vibration and vortex-induced vibration suppression device, the research scheme and train of thought of this paper are put forward. The mechanical model of deep water drilling riser unit is analyzed, and the equilibrium differential equation is established. The analysis model of 1200m deep riser system is established by OrcaFlex software, and the static and dynamic responses of the riser are compared and analyzed, which provides a theoretical basis for the selection of parameter conditions. The influence of wall thickness, top tension and drilling fluid density on the natural frequency of riser is studied, which provides a comparative basis for the analysis and study of vortex shedding frequency. It is concluded that vortex induced vibration is an important factor to study fatigue damage of riser, and the research direction is pointed out in this paper. The sensitivity analysis of parameters of deepwater drilling riser affected by environmental and operational factors is carried out. The effects of different factors on the dynamic response of the riser are obtained. On the basis of this, the orthogonal analysis of several sensitive parameters is carried out for the key factors, and the influence law of the key factors on the stiffness and strength of the deep water drilling riser system is obtained. This paper provides a theoretical basis for the study of vortex-induced vibration of riser and its suppression device. Using Fluent software, a two-dimensional numerical model of flow around the riser of deep water drilling is established, and the characteristics of the flow field around the riser under different velocity are studied. The influence of vortex-induced vibration on the riser at different depths is obtained by the variation of the coefficient of lift resistance and the frequency of vortex shedding. A new type of vortex suppression device is designed for the study of vortex suppression device of riser. Based on the research of the existing vortex suppression devices, a vortex excitation suppression device with arc tail is designed in combination with the vortex induced vibration mechanism. The structure analysis and optimization are carried out to improve the suppression efficiency of the new type of vortex suppression device. The vortex suppression device has good engineering application value and broad application prospect. In a word, the research work in this paper provides technical support and theoretical guidance for the study of mechanical characteristics, vortex-induced vibration and vortex-induced vibration suppression devices of deep water drilling risers, and has important guiding significance for the design and safe operation of risers. It will further promote the domestic research and industrial application of deepwater drilling riser. Therefore, the research of this paper not only has important theoretical significance and academic value, but also has a wide application prospect.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TE951

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