气体钻井井口装置冲蚀机理研究

发布时间：2018-03-23 05:24

本文选题：气体钻井　切入点：井口装置　出处：《西南石油大学》2015年硕士论文　论文类型：学位论文

【摘要】：近年来,随着气体钻井的不断发展,在各大油气得到了广泛的应用,气体钻井技术对保护油气层和提高钻速的优点很明显,但其中存在的高速气流携带岩屑冲蚀井口装置的问题不受重视。在高压高产气井钻井过程中,气流携带岩屑冲蚀磨损井口装置,造成井口装置的穿刺失效,可能造成重大的人员伤亡和不可挽回的经济损失,严重危害了现场施工的人员安全和环境问题。本文基于FLUENT计算流体力学软件,针对气体钻井过程中高速气流携带岩屑对井口装置中的排砂管线和多功能四通造成的冲蚀问题,建立对应的冲蚀模型,并对其冲蚀机理进行了较为全面的研究。本文从以下几个方面对井口装置中的排砂管线和多功能四通进行了冲蚀分析。 (1)从排砂管线的结构参数和工况参数着手,模拟分析了排砂管线在不同弯径比、不同弯角、不同管径下的冲蚀情况,研究表明随着弯径比、弯角和管径的增大,其冲蚀率随之降低；模拟分析了排砂管线在不同气体流量、不同岩屑速度、不同岩屑粒径等工况参数下的冲蚀情况,研究表明随着气体流量、岩屑速度和岩屑直径的增加,其冲蚀速率也随之增大。 (2)在某气井钻井过程中进行了排砂管线现场挂片实验,实验分析了岩屑颗粒冲蚀排砂管线的特点。 (3)数值分析了多功能四通在不同气体流量、岩屑流量和岩屑粒径等工况参数条件下的冲蚀情况,研究表明随流量和直径等因素的增加,冲蚀速率也随之增大；数值分析了不同旁通出口压力和不同旁通出口直径下的冲蚀,发现随着压力和直径的增加,其冲蚀速率随之变小。 (4)根据对排砂管线和多功能四通冲蚀机理的数值分析,提出了对排砂管线和多功能四通的优化设计,并模拟分析了优化设计结构的防冲蚀原理。根据模拟结构分析可知,在现场实际工程中,在实际条件允许的条件下,应减少排砂管线的弯头数,采用较大口径、较大弯径比的排砂管线；选用旁通出口直径较大的多功能四通,同时在其出口加一定的回压,降低其冲蚀速率。
[Abstract]:In recent years, with the continuous development of gas drilling, gas drilling technology has been widely used in various oil and gas, the advantages of gas drilling technology to protect oil and gas reservoirs and improve drilling speed are obvious. However, the problem of high speed airflow carrying cuttings is not paid much attention to. In the drilling process of high pressure and high production gas wells, the air carried cuttings erode and wear the wellhead devices, which results in the puncture failure of the wellhead devices. It may cause heavy casualties and irreparable economic losses, and seriously endanger the safety of personnel and environmental problems. In this paper, based on FLUENT computational fluid dynamics software, a corresponding erosion model is established in view of the erosion problem caused by high speed airflow carrying cuttings to the sand discharge pipeline and multifunction four-way in the wellhead device during gas drilling. In this paper, the erosion of sand discharge pipeline and multi-function four-way in the wellhead device are analyzed from the following aspects. 1) the erosion of sand discharge pipeline under different bending diameter ratio, different bend angle and different pipe diameter is simulated and analyzed from the structure parameters and working condition parameters. The results show that with the increase of bending diameter ratio, bend angle and pipe diameter, the erosion of sand discharge pipeline under different bending diameter ratio, different bend angle and different pipe diameter is simulated and analyzed. The erosion rate of sand discharge pipeline is reduced, and the erosion conditions of sand discharge pipeline under different working conditions such as gas flow rate, different cuttings velocity and different cuttings diameter are simulated and analyzed. The results show that with the increase of gas flow rate, cuttings velocity and cuttings diameter, The erosion rate also increases. (2) during the drilling process of a gas well, the field hanging experiment of sand discharge pipeline is carried out, and the characteristics of cuttings grain erosion and sand drainage pipeline are analyzed experimentally. (3) the erosion rate of multi-function four-way system under the conditions of different gas flow rate, cuttings flow rate and cuttings diameter is analyzed numerically. The results show that the erosion rate increases with the increase of flow rate and diameter. The erosion rate of different bypass outlet pressure and diameter is analyzed numerically. It is found that the erosion rate decreases with the increase of pressure and diameter. 4) based on the numerical analysis of the erosion mechanism of sand discharge pipeline and multi-function four-way, the optimum design of sand discharge pipeline and multi-function four-way is put forward, and the anti-erosion principle of the optimized design structure is simulated and analyzed. According to the analysis of simulated structure, in the field engineering, under the condition of actual condition, the number of sand discharge pipe should be reduced, and the sand discharge pipeline with larger diameter and bigger ratio of bending diameter should be adopted. The multi-function four-way with larger diameter of bypass outlet is selected, and at the same time, the erosion rate is reduced by adding a certain back pressure to the outlet.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE242.9

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