膨胀波纹管封隔定向井段应用技术研究

发布时间：2019-05-27 23:40

【摘要】：膨胀波纹管技术作为处理井下复杂情况的有效手段,在解决地层严重漏失、易坍塌和易缩径等方面具有独特优势,已在直井段应用中取得良好效果,但在定向井段中受井眼条件的影响,应用成功率还需进一步提高。本文在前期自主研发四种型号膨胀波纹管的基础上,以现场实际需求为出发点,采用理论分析、仿真模拟计算和室内试验相结合的方法,对膨胀波纹管封隔定向井段复杂地层的可行性进行了深入分析;形成了端头整形和焊缝质量检测及评价方法,改善了焊缝性能;研发了螺旋式胀管器和定向随钻扩眼钻头,提高了现场施工效率和可靠性。为了确定膨胀波纹管在定向井段中应用的适用性,采用有限元模拟分析的方法,建立管串和井眼模型,模拟分析不同井径、井斜角变化率和方位角变化率等井眼条件下,膨胀波纹管的外径、最大等效应力和最大等效塑性应变随膨胀压力的变化规律。根据分析结果,室内模拟了管串在弯曲井筒中的膨胀试验,为了解膨胀波纹管在井下膨胀状态提供了参考。针对膨胀波纹管端头形状的一致性差的问题,研制了三瓣楔形整形装置,可将端头对口错边量由4mm~5mm减少到1mm以内,提高了焊缝稳定性。针对焊缝检测方法和性能评价标准缺失的现状,引入了数字化X射线平板成像技术,结合处理软件,可准确识别缺陷的类型、尺寸及所处的位置,检测精度可达0.01mm。采用ABAQUS软件分析与室内试验相结合的方法,得出了气孔型、未焊透型和裂纹型缺陷在30MPa膨胀压力下的临界失效尺寸,为焊缝的质量检测提供了依据。针对小尺寸胀管器强度低,膨胀效率和效果不理想的问题,设计了螺旋式胀管器,采用一体化结构,具有低摩阻和高耐磨特性,可更好应对井下复杂情况。针对膨胀波纹管需要钻后扩眼的现状,研制了定向随钻扩眼钻头,定向钻进过程中可将井径扩大至设计要求,有效节省处理复杂情况的时间。本文研究成果在大牛地气田定向段易坍塌地层中成功应用2口井,其中PG22井中首次实现了国内膨胀波纹管技术在定向井段中成功应用,封隔段长为109.0m,最大井斜角为73.69°,在DPT-112井中单次应用膨胀波纹管的长度达到了132.7m。通过本文的研究,在明确膨胀波纹管井下膨胀状态,提高管串性能稳定性,完备配套工具等方面取得明显进展,为提高井下作业安全提供了新技术手段。
[Abstract]:As an effective means to deal with underground complex conditions, expansive bellows technology has unique advantages in solving serious formation leakage, easy collapse and easy shrinkage, and has achieved good results in the application of straight well section. However, due to the influence of hole conditions in directional well section, the success rate of application needs to be further improved. In this paper, on the basis of independent research and development of four types of expansion bellows in the early stage, taking the actual demand on the spot as the starting point, the method of combining theoretical analysis, simulation calculation and laboratory test is adopted. The feasibility of sealing the complex formation of directional well section with expansive bellows is analyzed in detail. The end shaping and weld quality detection and evaluation methods are formed to improve the weld performance, and the spiral pipe expander and directional hole while drilling bit are developed to improve the field construction efficiency and reliability. In order to determine the applicability of expansive bellows in directional well section, the finite element simulation analysis method is used to establish the pipe string and wellbore model, and to simulate and analyze the wellbore conditions such as different well diameter, well inclination angle change rate and azimuth change rate. The variation of the outer diameter, maximum equivalent stress and maximum equivalent plastic strain of expansive bellows with expansion pressure. According to the analysis results, the expansion test of pipe string in curved wellbore is simulated in laboratory, which provides a reference for understanding the expansion state of expansion bellows in underground. In order to solve the problem of poor consistency of the end shape of the expanded bellows, a three-flap wedged shaping device has been developed, which can reduce the number of wrong edges between the ends from 4mm~5mm to less than 1mm, and improve the stability of the weld. In view of the lack of weld detection methods and performance evaluation standards, digital X-ray plate imaging technology is introduced, combined with processing software, the type, size and position of defects can be accurately identified, and the detection accuracy can reach 0.01 mm. By using the method of ABAQUS software analysis and laboratory test, the critical failure dimensions of porosity, unwelded penetration and crack defects under 30MPa expansion pressure are obtained, which provides the basis for the quality inspection of welds. In order to solve the problems of low strength and unsatisfactory expansion efficiency and effect of small size tube expander, a spiral tube expander is designed, which adopts integrated structure and has the characteristics of low friction and high wear resistance, so it can better deal with the underground complexity. In view of the present situation that the expanded bellows need to be expanded after drilling, a directional reaming bit while drilling is developed. In the process of directional drilling, the well diameter can be extended to the design requirements, and the time to deal with complex situations can be effectively saved. The research results of this paper have been successfully applied in the collapsible formation of the directional section of Daniudi gas field. Among them, the domestic expansive bellows technology has been successfully applied in the directional well section for the first time in PG22 well, and the length of the sealing section is 109.0 m. The maximum deviation angle of the well is 73.69 掳, and the length of expansion bellows is 132.7 m in DPT-112 well. Through the research in this paper, obvious progress has been made in defining the downhole expansion state of expansive bellows, improving the performance stability of pipe strings and completing supporting tools, which provides a new technical means for improving the safety of downhole operation.
【学位授予单位】：中国地质大学(北京)
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TE358

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