Design of Magnet and Antenna for decentralized downhole Nuclear Magnetic Resonance Logging Tool
Nuclear magnetic resonance logging technology has the unique superiority as the only method to evaluate the reservoir porosity and identify fluid at the same time.In this technology, the static magnetic field generated by the permanent magnet is used to polarize the hydrogen atoms in the pores of the rock, and then the polarized hydrogen atoms are relatched by the alternating magnetic field, and then the spin echo signal is excited.The spin echo signal The nuclear magnetic resonance spectra of the pore structure and fluid properties were obtained, and the fine evaluation of the complex oil and gas reservoirs was realized by collecting, processing and inverting calculations.Based on the basic principle of nuclear magnetic resonance field generation, a new type of magnet and antenna structure of underground nuclear magnetic resonance logging tool is designed by numerical simulation software.The magnetic field distribution of different geometrical and material parameters under this structure is analyzed and optimized The magnetic field and the RF magnetic field are 90 degrees orthogonal to each other in the range of the designed detection area, which provides the prerequisite for the excitation of the nuclear magnetic resonance spin echo signal in theory.The correctness of the magnetic resonance echo signal was measured by magnet, antenna model machining and indoor water tank test.The correctness of the structure design of the magnet and antenna was verified, which laid the foundation for the development of underground magnetic well logging tool.
Nuclear magnetic resonance permanent magnet static magnetic field radio frequency field spin echo
Hou Xueli Tang Tianzhi Liao Guangzhi Li Mengchun Sun Zhe Zhu Wanli Luo Sihui Fang Lu Shi Guanghui
China Petroleum Logging CO.LTD.Xian, Shaanxi 710077 China University of Petroleum-Beijing, 102249
国际会议
西安
英文
190-198
2017-09-20（万方平台首次上网日期，不代表论文的发表时间）