摘要
复杂钻井条件下随钻采集岩屑难以真实反应地层岩性,因而单纯依靠岩屑描述建立地层岩性剖面难免存在误差。该文从常规地质录井岩性描述角度出发,探讨了结合气测、地化、定量荧光等录井方法建立地层岩性剖面的具体方法;提出“岩屑体积跟踪法”识别真假岩屑和“去尾法”落实地层底界方面的作法;同时针对岩屑混杂、细碎,甚至呈粉末状给岩屑描述造成困难,阐述了应用岩屑自然伽马检测值落实岩性的方法及可行性。进而为在复杂钻井条件下建立地层岩性剖面提供了保障。
On the complex drilling conditions,the cutting sample got in real time is hard to reflect the true formation,it is possible to make mistakes in establishing the formation lithology profile only by the cutting description.From the point of conventional geologging lithology description,the specific methods of setting up formation lithology profile were discussed in the paper with mud logging methods,such as gas logging,geochemical logging and quantitative fluorescence and so on .This paper set forth the usual way of “cutting volume tracing”to identify true or false cuttings,and discarding “the false cuttings ”to determine formation bottom boundary,simultaneously,it discussed the difficulties existed in using miscellaneous,fine,or powder cuttings to describe lithology,and the methods and feasibility of applying cutting natural gamma check value to decide lithology ,therefore,these methods provide a guarantee for setting up formation lithology profile under complex drilling conditions.
关键词
录井技术
地层
岩性剖面
气测方法
荧光方法
自然伽马检测值
钻井
岩屑
complex drilling,lithology profile,lithological description,gas logging,geochemistry,fluorescence,natural gamma
