滑动导向钻井PDC钻头钻进力学研究

发布时间：2017-12-31 07:31

本文关键词：滑动导向钻井PDC钻头钻进力学研究　出处：《西南石油大学》2017年硕士论文　论文类型：学位论文

【摘要】：PDC钻头滑动导向钻井是油气钻井工程中的一种典型复杂钻井方式,可有效提高破岩效率并用于控制井身轨迹,主要包括造斜和复合钻进两个阶段。"PDC钻头数字化钻井仿真技术"是近年来发展起来的一种研究钻头在地层中钻进切削力学行为的先进技术手段,它能够模拟复杂运动条件下钻头与岩石的互作用过程。PDC钻头在滑动导向钻井工况下,受井身结构、地层条件以及下部钻具组合约束,常导致钻头出现"掏心"、"环槽"以及"缩颈"等严重失效形式的发生。在研讨了 PDC钻头在滑动导向钻井中的失效机理的基础上,本文主要开展了以下工作:(1)通过研究定向井、水平井下部钻柱的受力变形特性,得到了不同稳定器数目下,螺杆弯臂的柔性弯角大小和挠度。在此基础上,建立了 PDC钻头在滑动导向钻井条件下(包括造斜阶段和复合钻进)的运动学模型。(2)研究了 PDC切削齿坐标位置、井斜角、稳定器位置和个数、螺杆结构参数(包括螺杆弯臂的柔性弯角和弯臂长)和转速比等因素对切削齿运动轨迹的影响。采用四因素四水平的正交仿真实验,探讨了多因素共同作用下切削齿径向覆盖范围和心部产生的"回旋"距离的极差分析和方差分析。(3)修正了 PDC切削齿破岩过程中的力学模型,并分别得出了适用于南充砂岩、武胜砂岩和灰岩的CD2值。(4)在新的力学模型的基础上,改进和完善了 PDC钻头数字化钻井仿真系统,并利用该系统进行了 6" PDC钻头偏心钻进的仿真实验,通过与相同条件下PDC钻头的室内偏心实验结果进行对比,验证了该仿真系统的可靠性。(5)开展了滑动导向钻井在两种不同工作模式下PDC钻头钻进均质岩石(武胜砂岩)的力学行为分析,深入研究了钻头与岩石的互作用规律,分别得出了造斜阶段的井底形貌、PDC切削齿的切削量、切削载荷和不同螺杆马达外径、螺杆马达柔性弯角、稳定器外径、长度和位置下导向力的变化,以及复合钻进工况下的井底形貌、PDC切削齿的不均衡接触状态、牙齿侵入特点、切削量、切削载荷和针对不同地层条件下转速比和螺杆弯角的选用等结果。(6)针对PDC钻头的钻进力学行为和失效机理,分别探讨了造斜和复合钻进中PDC钻头个性化设计的技术思想和实施方法。研究结果提高了对滑动导向钻井,包括造斜和复合钻进两个工况下,PDC钻头破岩的机理认识,新的认识能够对钻头的性能表现作出合理解释,并为钻头工作性能分析和个性化设计提供参考依据。
[Abstract]:PDC bit sliding steering drilling is a typical complex drilling method in oil and gas drilling, which can effectively improve the rock breaking efficiency and control wellbore trajectory. The digital drilling simulation technology of PDC bit is an advanced technique to study the cutting force behavior of bit drilling in formation in recent years. It can simulate the interaction process between bit and rock under complex moving conditions. PDC bit is constrained by well structure formation conditions and lower drilling tool combination under sliding steering drilling conditions. It often leads to the occurrence of serious failure forms such as "core pulling", "ring groove" and "necking". The failure mechanism of PDC bit in sliding steering drilling is discussed. This paper mainly carried out the following work: 1) by studying the stress and deformation characteristics of the bottom drill string in the directional well and horizontal well, the number of stabilizers is obtained. Flexible angle and deflection of screw bending arm. On this basis. The kinematics model of PDC bit under the condition of sliding steering drilling (including diagonal stage and compound drilling) is established. The coordinate position, well angle, stabilizer position and number of PDC cutting teeth are studied. The influence of screw structure parameters (including flexible bending angle and bending arm length) and rotational speed ratio on the cutting tooth trajectory was studied. The orthogonal simulation experiment was carried out with four factors and four levels. The range analysis and variance analysis of the "rotary" distance generated by the radial cover and the center of the cutting teeth under the combined action of many factors are discussed. The mechanical model of PDC cutting teeth during the rock breaking process is modified. The CD2 value. 4) suitable for Nanchong sandstone, Wusheng sandstone and limestone is obtained. On the basis of the new mechanical model, the digital drilling simulation system of PDC bit is improved and perfected. The simulation experiment of 6 "PDC bit eccentricity drilling is carried out by using this system, and the results are compared with the indoor eccentricity test results of PDC bit under the same conditions. The reliability of the simulation system is verified. The mechanical behavior analysis of PDC bit drilling in homogeneous rock (Wusheng sandstone) under two different working modes is carried out. The interaction between bit and rock is studied in depth. The bottom hole topography and cutting load of PDC cutting teeth, different screw motor outer diameters and flexible bending angle of screw motor are obtained respectively. The outside diameter, length and position of the stabilizer, the change of guiding force under the condition of composite drilling, the uneven contact state of the bottom hole profile of PDC cutting teeth, the characteristics of tooth invasion, and the cutting quantity. Cutting load and the selection of rotational speed ratio and screw bending angle under different formation conditions etc.) aiming at the drilling mechanical behavior and failure mechanism of PDC bit. The technical idea and implementation method of individualized design of PDC bit in diagonal drilling and compound drilling are discussed respectively. The research results improve the performance of sliding steering drilling, including slanting and compound drilling. The new understanding of the mechanism of rock breaking of PDC bit can reasonably explain the performance of bit and provide a reference for the analysis of bit working performance and individualized design.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE921.1

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