Real-Time Interpretation of Leak Isolation with Degradable Diverter Using High Frequency Pressure Monitoring

摘要

Degradable diverters are commonly used in multistage fracturing to increase the number of fractures along the wellbore and provide temporary isolation. Still, interpreting the effects of a diverter downhole remains challenging. In this paper, a nonintrusive monitoring technique is presented, which enables interpreting the effects of the diverter on multistage fracturing treatments. This technique relies on the processing of pressure data acquired at high frequency. Unlike other monitoring techniques, its deployment is straightforward and relies only on surface acquisition and interpretation algorithms. It does not necessitate any change or additional steps in operations by utilizing events which are part of fracturing treatments. Data are interpreted on-site and in real time, and the results lead to an improved understanding about the performance of the diverter downhole, the evolutions of the wellbore connectivity with the formation, and the degradation process of the diverter. The high-frequency pressure monitoring (HFPM) technique was used during several multistage fracturing operations. We present a case where the degradable diverter was used to effectively plug a leak during the fracturing treatment. The leak had inadvertently developed in a region of the well toward the heel, threatening the fracture stimulation stage aimed at the toe of the well. The HFPM technique was used to locate the leak, confirm its successful plugging with a degradable diverter, and monitor the degradation of the diverter. The HFPM provided control of the leak and data on when to pump additional diverter and the effects of the operation. The example demonstrates in a compelling manner that the HFPM technique enables real-time decisions that ultimately improve multistage fracturing treatments and operations relying on effective isolation and diversion. The HFPM presented herein is a novel, nonintrusive method for monitoring multistage operations and enabling real-time decisions. The technique is particularly valuable for monitoring treatments that rely on diversion and zonal isolation. HFPM is enabled by state-of-the-art signal processing and interpretation algorithms. It has the potential to become a ubiquitous technique that is part of each and every multistage fracturing treatment.