Low-frequency DAS interpretation upon multi-crew zipper fracturing configuration

Low-Frequency Distributed Acoustic Sensing (LF-DAS) is efficient in evaluating stimulation efficiency, investigating hydraulic fracture geometry, and optimizing well planning for the development of unconventional resources. Currently, most research is focused on the LF-DAS data acquired during the stimulation of one single horizontal well. This study investigates the field LF-DAS dataset in the Wattenberg field of the Denver-Julesburg (DJ) Basin, Colorado. The data was recorded from a retrievable wireline fiber horizontal well when seven neighboring 2-mile horizontal wells were stimulated by two frac crews within two weeks. It is challenging to interpret the complex LF- DAS dataset because 1) seven wells were hydraulically fractured simultaneously with a total of 322 hydraulic stages, and 2) some stages had overlapping pumping schedule and lead to co-occurring fracture signals. This study delves into the LF-DAS dataset stage by stage, assigns different types of fracture hit signatures to the most reasonable wells and stages, to understand the hydraulic fracture propagations in a complex operation sequence. This study tends to build a solid basis and standardized workflow for the interpretation of complex LF-DAS dataset recorded during the multi-well zipper fracturing treatment, and thus provides confidence in the investigation of well communication during stimulation.