随钻测量无线电磁传输系统的设计与实现

发布时间：2018-04-26 21:31

本文选题：随钻测井 + 电磁传输　；参考：《电子科技大学》2017年硕士论文

【摘要】：在地质勘查的钻井工程中,及时准确的监测井眼轨迹并精准调整钻井姿态是钻井工程中关键技术之一。目前,基于钻井液脉冲的数据传输方案普遍被国内外成熟的随钻测量系统(MWD)采用,但是这种传输方式受钻井液局限、传输速率低。随钻测量无线电磁传输系统是以低频电磁波为介质,将信号进行合适的编码后,经钻杆-地层信道传输到地面。它很好的克服传统钻井液脉冲无线传输技术的缺点,已成为国内外各大油服公司的研究热点。但国内该方面的研究起步较晚,技术远落后于国外大型同类公司,缺乏成熟的商用产品。因此具有自主核心技术的无线电磁传输系统的研发已成为国内业内公司与研发人员的一个攻坚任务。本课题以随钻测量无线电磁传输系统已有成果为背景,针对在随钻测量无线电磁传输系统实现中遇到的各种难题,进行设计与改进。主要工作包括:1.根据各项技术指标及实际工程情况,提出完整的系统方案,设计系统的总体功能框架;2.针对井下锂电池供电与长时间井下作业要求的矛盾,设计了专门的电源管理模块,实现发射系统在井下长时间待机与高效工作的需求;3.针对井下钻杆空间狭小,为发射系统提供的可利用空间有限,本文采用SOC方案实现信号的调制和发射系统的控制,有效的减少了发射系统的面积,非常方便井下电路的安装;4.受环境影响,井下通信信号衰减都比较快,载波频率都比较低,低频段的带宽较窄,本文采用BPSK调制方案,有效的降低了信号的带宽,并结合低频信号载波同步难的问题,本文设计了一种基于上下文的BPSK解调算法,该算法效率高,载波同步快,对噪声和工频信号都具有很好的抗干扰能力,并且该算法对硬件电路的要求低,本文采用FPGA实现该BPSK算法的解调,仅需FPGA最小系统和ADC即可;最后,针对该随钻测量无线电磁传输系统进行一系列相关的测试与实验,实验结果表明:该系统工作可长时间稳定工作,满足设计的各项技术指标,实现了预期功能。
[Abstract]:In the geological exploration drilling engineering, it is one of the key technologies in drilling engineering to timely and accurately monitor well trajectory and accurately adjust the drilling attitude. At present, the data transmission scheme based on drilling fluid pulse is generally adopted by the mature drilling measurement system (MWD) at home and abroad, but this transmission mode is limited by drilling fluid and low transmission rate. The wireless electromagnetic transmission system of drilling measurement is based on the low frequency electromagnetic wave as the medium, which is transmitted to the ground through the drill rod formation channel after the proper encoding of the low frequency electromagnetic wave. It is very good to overcome the shortcomings of the traditional drilling fluid pulse radio transmission technology, and has become a hot spot of research at home and abroad. The development of wireless electromagnetic transmission system with autonomous core technology has become a key task for domestic industry companies and R & D personnel. Various problems encountered in the implementation of the magnetic transmission system are designed and improved. The main work includes: 1. according to various technical indexes and actual engineering conditions, a complete system scheme is proposed and the overall functional framework of the system is designed. 2. a special power management model is designed for the contradiction between the power supply of the downhole lithium battery and the requirements of long time downhole operation. Block, realize the demand for long time standby and efficient work in the downhole. 3. in view of the narrow space of the downhole drill rod, the available space provided for the launching system is limited. In this paper, the SOC scheme is used to realize the control of the modulation and emission system of the signal, which effectively reduces the area of the emission system, is very convenient for the installation of the downhole circuit, and 4. is subjected to the ring. The attenuation of communication signals in the downhole is fast, the carrier frequency is low and the bandwidth of the low frequency section is narrow. In this paper, the BPSK modulation scheme is used to effectively reduce the bandwidth of the signal. In this paper, a BPSK demodulation algorithm based on the lower frequency signal is designed in this paper. The algorithm is efficient and the carrier synchronization is fast. Both the noise and the power frequency signal have good anti-interference ability, and the algorithm has low requirements for the hardware circuit. In this paper, the demodulation of the BPSK algorithm is realized by FPGA, only the FPGA minimum system and the ADC are needed. Finally, a series of related tests and experiments are carried out for the wireless electromagnetic transmission system with the drilled measurement. The experimental results show that the system is a series of tests and experiments. The whole work can work steadily for a long time to meet all the technical indexes of the design and achieve the expected function.

【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P634.3

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