复杂结构井磁导向钻井技术进展

复杂结构井可以有效提高复杂油气田单井产量和最终采收率，磁导向钻井技术是复杂结构井钻井的核心技术之一。总结了近年来磁导向钻井技术的主要研究进展，包括邻井距离随钻电磁探测系统、螺线管组随钻测距导向系统及三电极系救援井与事故井连通探测系统等主要研究成果，重点论述了磁导向钻井的技术原理及井下磁信标、弱磁探测仪、测距算法及纠偏控制方法等关键技术，并介绍了磁导向钻井技术在SAGD双水平井、连通井、救援井及丛式井钻井防碰中的现场应用情况。其中，邻井距离随钻电磁探测系统已在稠油SAGD双水平井钻井中得以成功应用，不仅在注入井水平段实现了磁导向水平钻进，而且在造斜井段也实现了磁导向钻进。分析认为，需加强多学科协同创新研究，以进一步提高磁导向钻井系统的耐温性能或研发新型耐高温磁导向钻井系统，实现磁导向钻井技术在复杂结构井的推广应用，提高钻井效率，保证钻井作业安全。 

Development of the Magnetic Guidance Drilling Technique in Complex Well Engineering

A complex well that display the characteristics of horizontal wells is an advanced well type and it effectively enhances single-well productivity and ultimate recovery in complicated oil and gas fields. The magnetic guidance drilling technique is one of the core techniques in complex well engineering. This paper presents the development of magnetic guidance drilling techniques, which involve the electromagnetic ranging tool for determining adjacent well distance while drilling, the electromagnetic ranging system based on a solenoid assembly while drilling, the ranging system based on three-electrode array for guiding a relief well to intersect a blowout well. This paper focuses on the introduction of technical principles, downhole magnetic beacons, downhole weak magnetic detectors, ranging algorithms, well trajectory control and other key techniques related to magnetic guidance drilling. The electromagnetic ranging system for the determination of adjacent well distance while drilling has been used successfully in the magnetic guidance drilling of twin horizontal SAGD wells for heavy oil development. It has been confirmed that the ranging system can be used to guide the well trajectory in directional drilling not only in horizontal sections but also in the building up sections. By strengthening coordinated researches involving multiple disciplines, the temperature-resistance performances of the magnetic guidance drilling systems can be further enhanced, and innovative high-temperature magnetic guidance drilling system can be developed. The application of magnetic guidance drilling techniques in complex wells can effectively enhance drilling efficiency and promote safety performances of such drilling operations.