The EGS Collab Project - Stimulations at Two Depths: Paper No. ARMA-2022-2261

T. Kneafsey, P. Dobson, C. Ulrich, C. Hopp, V. Rodriguez-Tribaldos, Y. Guglielmi, D. Blankenship, P. Schwering, M. Ingraham, J. Burghardt, M. White, T. Johnson, C. Strickland, V. Vermuel, H. Knox, J. Morris, P. Fu, M. Smith, H. Wu, J. Ajo-FranklinL. Huang, G. Neupane, R. Horne, W. Roggenthen, Jon Weers, T. Doe, T. Pyatina

Research output: Contribution to conferencePaper

3 Scopus Citations


The EGS Collab project, supported by the US Department of Energy, is performing intensively monitored rock stimulation and flow tests at the 10-m scale in an underground research laboratory to address challenges in implementing enhanced geothermal systems (EGS). Data and observations from the field tests are compared to simulations to understand processes and build confidence in numerical modeling of the processes. We have completed Experiment 1 (of 3), which examined hydraulic fracturing in a well-characterized underground fractured phyllite test bed at a depth of approximately 1.5 km at the Sanford Underground Research Facility (SURF) in Lead, South Dakota. Testbed characterization included fracture mapping, borehole acoustic and optical televiewers, full waveform sonic, conductivity, resistivity, temperature, campaign p- and s-wave investigations and electrical resistance tomography. Borehole geophysical techniques including passive seismic, continuous active source seismic monitoring, electrical resistance tomography, fiber-based distributed strain, distributed temperature, and distributed acoustic monitoring, were used to carefully monitor stimulation events and flow tests. More than a dozen stimulations and nearly one year of flow tests were performed. Quality data and detailed observations were collected and analyzed during stimulation and water flow tests using ambient temperature and chilled water. We achieved adaptive control of the tests using real-time monitoring and rapid dissemination of data and near-real-time simulation. More detailed numerical simulation was performed to answer key experimental design questions, forecast fracture propagation trajectories and extents, and analyze and evaluate results. Data are freely available from the Geothermal Data Repository. Experiment 2 examines the potential for hydraulic shearing in amphibolite at a depth of about 1.25 km at SURF. This site has a different set of stress and fracture conditions than Experiment 1. The Experiment 2 testbed consists of nine subhorizontal boreholes configured in two fans of two boreholes which surround the testbed and contain grouted-in electrical resistance tomography, seismic sensors, active seismic sources and distributed fiber sensors. A "five-spot" set of test wells that extends from a custom mined alcove includes an injection well and four production/monitoring wells. The testbed was characterized geophysically and hydrologically, and three stimulations have been performed using the Step-Rate Injection Method for Fracture In-Situ Properties (SIMFIP) tool to measure strains, and a new strain quantifying tool (downhole robotic strain analysis tool -DORSA) was deployed in a monitoring hole during stimulation. Real-time data were broadcast during stimulations to allow real-time response to arising issues.
Original languageAmerican English
StatePublished - 2022
Event56th U.S. Rock Mechanics/Geomechanics Symposium - Santa Fe, New Mexico
Duration: 26 Jun 202229 Jun 2022


Conference56th U.S. Rock Mechanics/Geomechanics Symposium
CitySanta Fe, New Mexico

NREL Publication Number

  • NREL/CP-6A20-85736


  • artificial intelligence
  • borehole imaging
  • production enhancement
  • production monitoring
  • reservoir characterization
  • reservoir simulation
  • upstream oil and gas
  • well intervention
  • wellbore seismic


Dive into the research topics of 'The EGS Collab Project - Stimulations at Two Depths: Paper No. ARMA-2022-2261'. Together they form a unique fingerprint.

Cite this