Abstract:
China is intensifying the development of unconventional and deep-sea hydrocarbon resources, which predominantly relies on deep and ultra-deep wells. However, perforation monitoring in such wells remains challenging as the vibrations induced by perforating charge explosions during casing perforation completion attenuate remarkably with well depth. Accordingly, we propose a monitoring method for tubing-conveyed perforation in deep wells based on variational mode decomposition(VMD). A wellhead vibration acquisition system is constructed using high-precision acceleration vibration sensors and high-resolution acquisition cards to capture wellhead vibration signals effectively, followed by the analysis of the sources and frequency ranges of these signals. We compare the time-domain features of vibration signals from pressure-activated tubing-conveyed perforation and wireline perforation in a horizontal well in Yanchang Oilfield, and decompose the pressure-initiated signals into different intrinsic mode function(IMF) in seven distinct frequency bands using the VMD technique. Each IMF component undergoes the Hilbert-Huang transform to differentiate perforation signals from pump pressure signals. The application demonstrates that the proposed approach optimally preserves perforation and surface vibration signals to enhance the monitoring precision for tubing-conveyed perforation in deep wells.