摘要
钻井过程中,可以通过随钻测量技术实时获取井下工程参数及地质参数。电磁随钻测量技术有着其他随钻测量技术难以比拟的优势,但其易受到地层电阻率的限制,导致电磁信号传输深度较浅,因此电磁信号的传输深度是电磁随钻测量技术发展和应用的最大制约因素。分析表明,采用中继传输技术是提高电磁信号传输深度最直接、经济的方法。为此,开展了井下电磁信号中继传输特性理论研究,确定了中继器电磁激励方式和天线结构,建立了井下电磁信号中继传输模型;设计了中继器开发方案。根据方案,完成了中继器工程样机的研制,并进行了现场应用实验。实验表明,采用井下电磁信号中继传输技术可有效提高EM-MWD仪器的传输深度,每级中继器可以提高传输深度70%以上,从而使电磁信号的传输深度不再受制于地层电阻率,拓展了EM-MWD仪器的使用范围。
In the drilling process real-time downhole engineering parameters and geological parameters can be obtained by the MWD technology which has greatly promoted the development of drilling technology. Electromagnetic MWD technology has unique advantages, but it is vulnerable to formation resistivity restriction and results in a smaller depth of electromagnetic signal transmission. Therefore, the transmitted depth of electromagnetic signal is the greatest constraint in the development and application of EM-MWD. The relay transmission technology is the best way to improve the transmission depth of electromagnetic signal. For this reason, in this paper theoretical research of electromagnetic signal transmission characteristics is conducted, and the electromagnetic excitation mode of repeater and the antenna structure are determined. Then an electromagnetic signal relay transmission model and a repeater development program are established. On this basis, the repeater and application experiments are developed. Experimental results show that the downhole electromagnetic relay transmission technology can improve the depth of EM-MWD. The transmission depth can be increased more than 70 percent by each repeater. Therefore, the use of EM-MWD is greatly expanded.
出处
《科技导报》
CAS
CSCD
北大核心
2015年第15期66-71,共6页
Science & Technology Review
