Research on the full life cycle monitoring of low fluid level in wells based on distributed fiber sensing

This research incorporates a comprehensive examination of the life-cycle fiber optic monitoring of horizontal wells in shale oil deposits. The study utilizes detailed data from the ZFH-1 well in the Changqing Oilfield, gathered through advanced technology such as the switchable sleeve. This approach allows for an in-depth investigation into fiber optic monitoring techniques, enhancing our understanding and application of these methods in the field of shale oil extraction.Utilizing the Hilbert-Fourier transform and a method of median filter optimization, this study examined the characteristics of the fracturing field during multistage fracturing. This was accomplished through the use of actual measurement data from horizontal well ZFH-1 in the Changqing Oilfield shale oil.By incorporating a comprehensive analysis of thermal effects, we have achieved a nuanced understanding of liquid production profiles across various fracturing stages and production systems. This insight has been gained through the strategic employment of the Levenberg-Marquardt inversion algorithm, which facilitated the precise interpretation of micro thermal effects, Joule- Thomson effects, and the intricate interplay between reservoir and wellbore. Consequently, this approach enables a robust quantitative evaluation, offering clarity and depth in understanding liquid production dynamics under diverse operational conditions.The results indicate that abnormal high-pressure signals were observed in the lower section of wellbore ZFH-1 during stages 2, 5, 6, 7, and 8. This suggests that fracturing fluid leaked into the upper segment of the wellbore. Consequently, there was a need to adjust the production system, changing its frequency from 3.8 times per day to 2.The frequency of nine times per day exerted a minimal influence on the overall liquid production pattern, yet it resulted in a significant decrease in the production of stage 8/9.This study demonstrates that integrating advanced fluid monitoring techniques with precise data interpretation models allows for an accurate evaluation of fluid production characteristics and reservoir reconstruction effects in horizontal wells within shale oil formations. This provides a robust foundation for optimizing production systems and guiding subsequent strategic decisions.