EGU25-121, updated on 14 Mar 2025
https://doi.org/10.5194/egusphere-egu25-121
EGU General Assembly 2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
Poster | Tuesday, 29 Apr, 14:00–15:45 (CEST), Display time Tuesday, 29 Apr, 08:30–18:00
 
vPoster spot 4, vP4.6
A Novel Q-Switch Technique for  Borehole NMR Measurement
Sihui Luo1,2, Xin Li3, Huiju Yu4,5, Zhengduo Wang2, Tianyu Xing2, Zhihao Long2, Cheng Che2, Guangzhi Liao, and Lizhi Xiao
Sihui Luo et al.
  • 1China University of Petroleum-Beijing, College of Carbon Neutral Energy, Beijing, China
  • 2China University of Petroleum-Beijing, State Key Laboratory of Petroleum Resources and Engineering, Beijing, China
  • 3SINOPEC Research Institute of Petroleum Engineering Co..Ltd, SINOPEC Key Laboratory of Well Logging, Beijing, China
  • 4National United Engineering Laboratory for Biomedical Material Modification, Shandong, China
  • 5Shandong University of Technology, School of Materials Science and Engineering, Shandong, China

Nuclear Magnetic Resonance (NMR) is a crucial logging technique for the unconventional and complex reservoir evaluation. However, the echo spacing is always an issue of borehole NMR measurement, which limits the performance of NMR tools to acquire the short relaxation components.

In this abstract, we proposed a novel Q-Switch technique aiming at breaking through the limitation of dead-time of borehole NMR logging tool, and to achieve much shorter echo spacing. Instead of using resistors of larger resistance in parallel with the radio-frequency (RF) coil to reduce the active dead-time, an inductive coupling circuit was introduced to decrease the ringing-down time significantly after transmitting the RF pulses with high voltage. The Q-Switch circuit consists of inductive coupling coil, capacitors, resistors and active high-voltage MOSFETs. The ringing-down time of RF system was decreased by at least 10 times compared to the system without using proposed Q-switch scheme, leading to echo spacing lower to 0.3 ms under the condition with resonant frequency lower to 500 kHz.

Both simulations and experiments were in great agreements, validating the feasibility and efficiency of proposed Q-switch scheme, and proved to be promising in the borehole NMR applications.

How to cite: Luo, S., Li, X., Yu, H., Wang, Z., Xing, T., Long, Z., Che, C., Liao, G., and Xiao, L.: A Novel Q-Switch Technique for  Borehole NMR Measurement, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-121, https://doi.org/10.5194/egusphere-egu25-121, 2025.