An Evaluation Method for Fracturing Temporary Plugging Based on Water Hammer Pressure Monitoring

The effectiveness of temporary plugging is one of the important index of temporary-plugging fracturing. However, there is currently a lack of research on temporary-plugging evaluation based on this technology. Downhole fracture monitoring technology based on water-hammer pressure waves can accurately capture the response of multiple fractures in the well after fracturing. Therefore, a temporary-plugging effectiveness evaluation method (WHBEM) based on water-hammer pressure cepstrum is innovatively proposed in this paper. Firstly, based on water-hammer cepstrum response of downhole fractures before and after temporary plugging, a efficiency calculation method based on the change of the energy proportion of each cluster response is proposed. Secondly, a penalty function based on changing trend of the fractures-energy-response ratio is proposed to correct the temporary-plugging efficiency of each fracture. Finally, the average value of the corrected temporary-plugging efficiency of each fracture is taken as the temporary-plugging effectiveness of this section, and an evaluation criterion for plugging performance is established. In this paper, the effect of 9 temporary-plugging-fracturing sections in a carbonate condensate gas well in Xinjiang are evaluated. The results show an average plugging effectiveness of 71% for the case well, with 5 stages rated as excellent and 4 as good, indicating overall excellent performance. Furthermore, the correlation coefficient between the WHBEM and Erf function is 0.57, demonstrating a consistent trend that aligns with the pressure increase observed during the plugging operation in each stage. The research concludes that by quantitatively assessing plugging efficiency through both the magnitude and trend of the water-hammer response of each fracture, the WHBEM provides more objective and accurate evaluation results. This research can offer effective guidance for the real-time control of temporary plugging operations in the field.