Challenges and Best Practices in Interpreting Cross-well Strain Signals to Monitor Multi-Crew Zipper Fracturing Operations

Abstract

Cross-well strain measurements using Low-frequency Distributed Acoustic Sensing (LF-DAS) is an emerging technique to monitor hydraulic fracture propagation. The qualitative interpretations of the strain rate data have been used to evaluate the fracturing stimulation efficiency, hydraulic fracture geometry, and cross-well communication. Limited studies have investigated the cross-well strain signals recorded from offset fibers during zipper fracturing treatment, though zipper fracturing becomes a routine method of stimulating horizontal wells in unconventional reservoirs. This gap will be filled in this research by presenting the methods we developed to investigate complicated LF-DAS signals. These approaches were further demonstrated using field datasets recorded along the two temporal sensing fiber cables during the zipper fracturing operation of seven offset wells with two fracking crews operating simultaneously. By exploring, comparing, and presenting the LF-DAS data recorded in wireline and disposable fiber cables, this research shares the best practices for visualizing and interpreting cross-well strain signals. The LF-DAS dataset shown in this study, which, to the best of our knowledge, is one of the most complicated LF-DAS datasets presented. The approaches proposed here can be extended and applied to visualize and interpret different kinds of complicated LF-DAS signals recorded using permanent, wireline, and disposable fiber cables.