Demonstration of Proof of Concept of Electromagnetic Geophysical Methods for High Resolution Illumination of Induced Fracture Networks

Abstract In April 2017, the Advanced Energy Consortium (AEC) successfully completed data collection for a proof-of-concept demonstration of remote mapping of hydraulically fractured networks using electromagnetic (EM) proppant additives and a variety of EM tools and configurations. This field-pilot demonstration was conducted at the Devine Test Site, located approximately 50 miles southwest of San Antonio, Texas, and managed by the Bureau of Economic Geology (Bureau) at The University of Texas at Austin. The objective of the ongoing integrated research program is to develop a remote EM-imaging technique for hydraulically fractured networks in order to obtain a higher-resolution image of proppant distribution (lateral/vertical extent and azimuth), which current technologies, such as microseismic, do not allow. The current study is a more in-depth follow-up to a series of shallow field tests that the AEC conducted in 2015 near Clemson University in South Carolina. This paper details the special aspects of the Devine Test Site that make it a unique asset for benchmarking EM-based hydraulic-fracture mapping tools and models. Results from the Devine Test Site demonstrate that a measurable and noticeable EM anomaly was detectable with both time-domain and frequency-domain induced polarization methods. EM- inversion results were consistent with analysis of surface tiltmeter results but diverged significantly from passive seismic responses obtained during the hydraulic-fracturing process. The site will be cored at multiple locations over the next few months, after which accuracy of models and methods will be validated. Future opportunities for collaboration on this highly validated benchmarked site are discussed.