气体钻井钻杆完井基础理论研究

发布时间：2018-06-10 02:06

本文选题：气体钻井 + 压缩因子　；参考：《西南石油大学》2015年硕士论文

【摘要】：气体钻井技术是实现深层致密砂岩气藏高效勘探开发的有效技术手段。但是,在深层致密砂岩气藏钻井过程中面临深井、高压、高产等地质及工程问题,使用气体钻井技术钻开储层存在较高的安全风险。因此,工程上提出了气体钻井钻杆完井技术。本文通过文献调研、理论分析以及数值计算,对气体钻井钻杆完井相关的基础理论问题开展了研究,主要包括：高压天然气压缩因子模型优选和评价；不同工况下气体钻井井筒温度分布模型建立与分析；气体钻井钻杆完井不同工况井筒内气体流动规律研究。其主要研究方法和取得的研究成果如下：(1)通过对DAK模型、LXF模型、Hall模型编程计算,并与Standing-Katz天然气压缩因子图版结果进行对比和适应性评价,形成了一套气体钻井钻杆完井从低压～中压～高压流动的全域压缩因子数学模型。(2)根据热力学第一定律、热力学理论以及传热学理论,以钻柱内流体、管柱壁、环空内流体作为研究对象,建立了循环和非循环工况下钻柱内流体、管柱壁、环空内流体的气体钻井井筒温度分布数学模型,并进行数值计算。数值计算结果表明,气体钻井循环期间,随着井深的增加钻柱和环空内的温度都逐渐升高；非循环期间,随着非循环时间的增加,环空温度逐渐升高,而随着时间的增长,非循环温度变化越来越缓慢。(3)在全域天然气压缩因子计算模型、循环和非循环井筒温度分布模型研究的基础上,根据建立的气体钻井井内控制方程,对气体钻井钻杆完井不同工况井筒流动规律进行了研究。数值计算结果表明,当产气量小时可以采用常规完井方式进行不压井起下钻完井,而当产气量大时则需要用钻杆完井；气体钻井钻杆完井测试过程中井筒内的压力随井深的增加而逐渐增大,且当油嘴尺寸变化时,井筒环空的压力随之改变,油嘴尺寸越小井筒环空压力越大；关井时随着关井时间的增加,井底压力逐渐增大,直至与地层压力平衡；投产时油嘴尺寸越小钻杆和井底的压力越大。通过本论文研究,为深层致密砂岩气藏气体钻井钻杆完井技术的实施和优化提供了理论支撑。
[Abstract]:Gas drilling technology is an effective technique to realize high efficiency exploration and development of deep tight sandstone gas reservoir. However, in the drilling process of deep tight sandstone gas reservoir, there are many geological and engineering problems, such as deep well, high pressure, high yield and so on. There is a high safety risk in drilling reservoir with gas drilling technology. Therefore, the gas drilling pipe completion technology is put forward in engineering. Based on literature research, theoretical analysis and numerical calculation, the basic theoretical problems related to gas drilling pipe completion are studied in this paper, including: selection and evaluation of high pressure natural gas compression factor model; The model of wellbore temperature distribution in gas drilling under different working conditions is established and analyzed, and the gas flow law in the wellbore of gas drilling pipe completion under different conditions is studied. The main research methods and results obtained are as follows: 1) the DAK model / LXF model / Hall model is programmed and calculated, and the results are compared with the results of Standing-Katz natural gas compression factor chart and their adaptability is evaluated. A set of global compressibility factor mathematical models for gas drilling pipe completion from low pressure to medium pressure to high pressure is formed. According to the first law of thermodynamics, the theory of thermodynamics and the theory of heat transfer, the fluid in the drill string and the wall of the pipe string are used. The mathematical model of wellbore temperature distribution of drilling string, string wall and annulus fluid under cyclic and off-cycle conditions is established and calculated numerically. The numerical results show that during the gas drilling cycle, the temperature of the drill string and annulus increases gradually with the increase of well depth, and the annulus temperature increases gradually with the increase of the non-circulating time during the off-cycle period, but with the increase of time, the temperature of the annulus increases with the increase of the depth of the well. On the basis of the calculation model of natural gas compressibility factor and the temperature distribution model of circulating and off-circulation wellbore, the governing equation of gas drilling wells is established. In this paper, the wellbore flow law of gas drilling pipe completion under different working conditions is studied. The numerical results show that the conventional completion method can be used when the gas production is small, but the drilling pipe is needed to complete the well when the gas production is large. The pressure in the wellbore increases gradually with the increase of the well depth during the gas drilling pipe completion test, and when the nozzle size changes, the pressure of the wellbore annulus changes, and the smaller the nozzle size, the greater the wellbore annulus pressure. With the increase of shutoff time, the bottom hole pressure gradually increases until it is balanced with formation pressure, and the smaller the size of the oil nozzle and the greater the bottom hole pressure when put into production. This paper provides theoretical support for the implementation and optimization of gas drilling pipe completion technology in deep tight sandstone gas reservoirs.
【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】：TE257;TE242

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