新型油基钻井液随钻侧向电阻率测井方法研究

发布时间：2018-03-10 17:39

本文选题：测井　切入点：钻井液　出处：《浙江大学》2017年硕士论文　论文类型：学位论文

【摘要】：测井是在勘探和开采石油、天然气、煤、金属矿等地下矿藏的过程中,利用各种仪器监测井下地层的物理参数和井眼的技术状况,以解决地质和工程问题的一类工程技术的总称。地层的物理参数中,电阻率是反映地层岩性、含油气性等地层特性的关键参数之一,随钻侧向电阻率测井作为电阻率测井的一项重要技术在石油的勘探和开发中得到了广泛的应用。然而,目前随钻侧向电阻率测井技术往往只适用于导电的水基钻井液工况。在油基钻井液工况下,不导电的钻井液将测井仪器与被测地层隔离,导致测量难以进行。因而研究适用于油基钻井液工况的随钻侧向电阻率测井技术具有重要意义。本文将电容精合非接触电导测量(Capacitively Coupled Contactless Conductivity Detection,C4D)技术原理和感应耦合原理相结合,研究油基钻井液随钻侧向电阻率测井新方法,论文的主要工作和创新点如下:(1)将C4D技术原理和感应耦合原理相结合,提出了一种油基钻井液随钻侧向电阻率测井新方法。该方法利用C4D技术中的电容耦合原理克服油基钻井液不导电的影响,利用感应耦合原理构建交流测量回路的激励源,从而形成交流测量回路,进而实现油基钻井液下地层电阻率的测量。(2)针对提出的油基钻井液随钻侧向电阻率测井新方法,建立了相应的油基钻井液随钻侧向电阻率测量模型。该模型为激励源(由感应耦合原理构建)、两个耦合电容(分别由螺线环形激励线圈上侧钻铤和下侧环形检测电极通过油基钻井液与井壁形成)、待测地层等效电阻串联形成的交流测量回路模型。(3)为了验证所建立模型的有效性,利用COMSOLMultiphysics有限元仿真软件根据所提出的方法及模型建立了仿真模型。通过仿真,验证了所建立的随钻侧向电阻率测井模型的有效性,并建立了地层电阻与电阻率的仿真映射关系。(4)设计研发了一套针对实际6.75"钻铤的随钻侧向电阻率测井样机,包括传感器及其信号采集与处理系统。传感器基于所提出的测井新方法及其模型进行设计和研发。信号检测与处理系统将传感器输出的电流信号放大并转化为电压信号后,再利用NI数据采集仪采集并转化为数字信号。最后采用数字相敏解调(Digital Phase Sensitive Demodulation,DPSD)技术实现电阻率的测量。(5)设计了一套模拟测井实验装置,该实验装置主要包括随钻侧向电阻率测井样机、模拟地层、模拟井眼以及实验台架。并通过实验进一步验证了所提出的油基钻井液随钻侧向电阻率测井新方法及其样机的可行性和有效性。
[Abstract]:Logging is the process of exploration and exploitation of underground mineral deposits such as oil, natural gas, coal and metal mines, and the use of various instruments to monitor the physical parameters of the underground formation and the technical condition of the borehole. A general term for a class of engineering techniques to solve geological and engineering problems. Among the physical parameters of strata, resistivity is one of the key parameters that reflect the characteristics of strata, such as lithology, oil and gas, etc. As an important technology of resistivity logging, lateral resistivity logging while drilling has been widely used in oil exploration and development. At present, the lateral resistivity logging technology while drilling is usually only suitable for conducting water-based drilling fluid. Under the condition of oil-base drilling fluid, the non-conductive drilling fluid separates the logging tool from the formation under logging. Therefore, it is of great significance to study the lateral resistivity logging technology suitable for oil based drilling fluid. In this paper, the principle of Capacively Coupled Contactless Conductivity Detection C4D is combined with the inductive coupling principle. A new method of oil-base drilling fluid lateral resistivity logging while drilling is studied. The main work and innovation of this paper are as follows: 1) combining the principle of C4D technology with the principle of induction coupling. A new method of lateral resistivity logging for oil-base drilling fluid while drilling is proposed, which uses the principle of capacitive coupling in C4D technology to overcome the influence of non-conductivity of oil-base drilling fluid, and uses the principle of induction coupling to construct the excitation source of AC measuring loop. Thus the AC measurement loop is formed, and then the formation resistivity measurement under oil-base drilling fluid is realized. Aiming at the proposed new method of oil-base drilling fluid lateral resistivity logging while drilling, The model of lateral resistivity measurement of oil-base drilling fluid while drilling is established. The model is an exciting source (constructed from induction coupling principle), and two coupling capacitors (the upper collar and the lower side ring respectively) of the spiral ring excitation coil are used to detect the resistivity. In order to verify the validity of the established model, the electrode is formed by oil-base drilling fluid and wellbore, and the AC measurement loop model formed by the equivalent resistance of the formation to be tested in series is established in order to verify the validity of the established model. The simulation model is established by using COMSOLMultiphysics finite element simulation software according to the proposed method and model. The validity of the established lateral resistivity logging model while drilling is verified by simulation. The simulation mapping relationship between formation resistance and resistivity is established. A set of lateral resistivity logging prototypes for actual 6.75 "drill collar is designed and developed. The sensor is designed and developed based on the proposed logging method and its model. The signal detection and processing system amplifies the current signal from the sensor and converts it into a voltage signal. Finally, the digital phase sensitive demodulation Phase Sensitive Demodulation dpd) technique is used to realize the resistivity measurement. A set of analog well logging experiment device is designed. The experimental device mainly includes a prototype of lateral resistivity logging while drilling to simulate the formation. The feasibility and effectiveness of the proposed lateral resistivity logging method for oil-base drilling fluid while drilling and its prototype are further verified by experiments.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE254;P631.81

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