深煤层煤层气井低伤害完井液研究

发布时间：2018-04-01 23:04

本文选题：煤层气　切入点：深煤层　出处：《西南石油大学》2015年硕士论文

【摘要】：我国煤层气资源丰富,随着浅部勘探的基本完成,1000m以深的煤层气的勘探开发已成为必然趋势,深煤层是非常规能源的又一发展方向。然而,相对浅煤层而言,深煤层具有更多的难点,比如具有温度梯度高、地应力高、变质程度高和孔隙结构配制差等特点,这就对深煤层的钻井施工提出了更高的要求。在该类储层的实际钻井过程中,储层保护的问题几乎很少被考虑,特别是目前煤层气的开采单井产量过低以及由此而带来的综合成本难以降低已成为制约我国煤层气发展的严重障碍。因此,揭示煤层气储层损害机理,研究出适合深煤层煤层气井的低伤害完井液势在必行。本文以沁水盆地柿庄北区块3号煤和15号煤为研究对象,对3号煤和15号煤的物性特征进行对比,并分析了煤岩物性随煤层埋深的变化规律。在总结储层特征的基础上,通过敏感性实验研究了储层的损害机理,有针对性地确定了深煤层煤层气井低伤害完井液体系的基础配方,并通过大量的室内实验,优选出了体系中的增黏降失水剂、密度调节剂、降滤失剂、黏土稳定剂、温度稳定剂、强抑制剂以及其他处理剂,形成了一套低密度、低伤害完井液体系配方,并对其抗温性、悬浮稳定性、密度可调性、抑制性、缓蚀性以及储层保护性能等方面进行了评价。该低伤害完井液体系以XC和CMC-HV作为体系的增黏降失水剂,空心玻璃微珠作为密度调节剂,CMC-HV、空心玻璃微珠和CaCO3共同配合降低滤失量,并通过添加强抑制剂、温度稳定剂、黏土稳定剂、缓蚀剂等其他处理剂,形成了一套性能良好的完井液体系配方,并很好的解决了低密度完井液体系常见的稳定性差和流变性差的难点。通过大量实验证明,该完井液体系具有良好的热稳定性能,很好的针对了深煤层温度较高的特点；在0.74-1.03g/cm3的范围内密度任意可调,且性能良好,体系稳定性强,很好的针对了煤储层普遍低压的特点；对储层具有很好的保护效果,完井液对储层渗透率的损害率仅有10%左右。故该深煤层煤层气井低伤害完井液技术的研究不但具有较强的理论意义,而且具有重要的实用价值。
[Abstract]:China is rich in CBM resources. With the basic completion of shallow exploration, the exploration and development of coal-bed methane (CBM) with depth of 1000m has become an inevitable trend, and deep coal seam is another development direction of unconventional energy.However, compared with shallow coal, deep coal has more difficulties, such as high temperature gradient, high ground stress, high degree of metamorphism and poor pore structure, which puts forward higher requirements for drilling construction of deep coal seam.In the actual drilling process of this kind of reservoir, the problem of reservoir protection is rarely considered.Especially, the low production rate of single well and the difficulty of reducing the comprehensive cost have become a serious obstacle to the development of CBM in China.Therefore, it is imperative to reveal the damage mechanism of coalbed methane reservoir and to study the low damage completion fluid suitable for deep coal seam coalbed methane wells.Taking No. 3 coal and No. 15 coal in Shizhuang North Block, Qinshui Basin as the research object, the physical properties of No. 3 coal and No. 15 coal are compared, and the variation law of coal and rock physical properties with coal seam burial depth is analyzed.On the basis of summing up reservoir characteristics, the damage mechanism of reservoir is studied through sensitivity experiments, and the basic formula of low damage completion fluid system in deep coal seam coalbed gas wells is determined, and a large number of laboratory experiments are carried out.A set of low density, low damage completion liquid system formulations were formed by selecting the viscosity and water loss agents, density regulators, filtration reducers, clay stabilizers, temperature stabilizers, strong inhibitors and other treatment agents in the system.Suspension stability, density adjustable, inhibition, corrosion inhibition and reservoir protection were evaluated.The low damage completion liquid system uses XC and CMC-HV as viscosity increasing and reducing water loss agent, hollow glass microsphere as density regulator CMC-HV.The hollow glass microsphere and CaCO3 cooperate to reduce filtration loss, and by adding strong inhibitor and temperature stabilizer,The clay stabilizer, corrosion inhibitor and other treatment agents have formed a set of well completion liquid system formula with good performance, and solved the common difficulties of poor stability and rheological property of low density well completion liquid system.Through a large number of experiments, it is proved that the well completion liquid system has good thermal stability, which is well aimed at the characteristics of high temperature in deep coal seam, and the density can be adjusted arbitrarily in the range of 0.74-1.03g/cm3, with good performance and strong system stability.It is well aimed at the characteristics of low pressure in coal reservoir and has a good protective effect on reservoir. The damage rate of completion fluid to reservoir permeability is only about 10%.Therefore, the study of low damage completion fluid technology in deep coal seam coalbed methane well is not only of great theoretical significance, but also of important practical value.
【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】：TE258

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