超高阻盐膏层随钻电磁中继传输特性研究

Research on Downhole Electromagnetic Repeater Transmission Characteristics in Ultra High Resistivity Gypsum-Salt Layers

陈晓晖 高炳堂 宋朝晖

CHEN Xiaohui GAO Bingtang SONG Zhaohui

中国石化石油工程技术研究院, 北京 100101

Sinopec Research Institute of Petroleum Engineering, Beijing, 100101, China

为解决超高阻盐膏层随钻电磁信号由于急速衰减易导致传输中断的问题，建立了超高阻盐膏层电磁中继转发模型，运用空间和阶次分别细化的自适应HP有限元算法，获得了超高阻地层环境下不同频率载波电磁中继信号衰减速度和传输距离的关系，形成了电磁中继器安装位置的预测方法，与常规有限元算法相比，该方法具有收敛速度和计算精度方面的优势。伊朗AGHA JARI区块AJ214井现场试验证明，应用所建模型计算的盐膏层电磁信号衰减速度与实际应用效果相符，中继器安装位置的预测准确率超过90%。研究表明，利用建立的传输模型可以准确预测中继器安装位置，充分发挥中继器转发能力，确保电磁信号可以在超高阻盐膏层连续传输，为电磁随钻测量技术的现场应用提供了理论参考。

In order to solve the problem that electromagnetic telemetry signal easily interrupts transmission in ultra high resistivity gypsum-salt layer due to fast attenuation,an adaptive HP finite element method (FEM),which could automatically select space or order thinning,was used to simulate the electromagnetic relay in ultra high resistivity gypsum-salt layers.The falling velocity and transmission distance of electromagnetic signals in ultra-high resistivity gypsum-salt layer under different carrier frequencies were obtained.A prediction method of relay installation position was formed,and compared with conventional finite element calculation.It had advantages in convergence rate and calculation accuracy.The the algorithm was verified correct in Well AJ214 of AGHA JARI Block,Iran.The calculation result of signal attenuation rate tallied well with the practical application,and the prediction accuracy of repeaters’ installation position was over 90%.The research showed that the transmission model could accurately predict the installation position of repeaters,and ensure the continuous transmission of electromagnetic signals across the ultra high resistivity gypsum-salt layer.The model can serve as a theoretical reference and foundation for EM-MWD applications.

国家科技重大专项"低渗透储层高精度随钻成像技术研究"（编号：2016ZX05021-002）资助。

https://doi.org/10.11911/syztjs.2018092