Lab-scale stimulation was performed on Coso samples obtained from a single core (1623 feet TVD, reservoir Coso CGC 18-27) using StimuFrac and control fluid in the absence of stimuli-responsive polymer.

CO2 breakthrough experiments in a column packed with sand and filled with StimuFrac fluid or water to learn about transport of the stimuli (CO2) on environments where either water or the stimuli-responsive polymer aqueous solution (StimuFrac) is present. Results suggest co-injection of StimuFrac and CO2 as the potentially best alternative to deploy this novel fracking fluid.

Lab-scale stimulation work on non-porous fused silica (similar mechanical properties to igneous rock) was performed using pure water, pure CO2 and water/CO2 mixtures to compare back to back fracturing performance of these fluids with PNNL's StimuFrac.

Characterizing the stimulation mode of a fracture is critical to assess the hydraulic efficiency and the seismic risk related to deep fluid manipulations. We have monitored the three-dimensional displacements of a fluid-driven fracture during water injections in a borehole at ~1.5 km depth in the crystalline rock of the Sanford Underground Research Facility (USA). The fracture initiates at 61% of the minimum horizontal stress by micro-shearing of the borehole on a foliation plane. As the fluid pressure increases further, borehole axial and radial displacements increase with injection time highlighting the opening and sliding of a new hydrofracture growing ~10 m away from the borehole, in accordance with the ambient normal stress regime and in alignment with the microseismicity. Our study reveals how fluid-driven fracture stimulation can be facilitated by a mixed-mode process controlled by the complex hydromechanical evolution of the growing fracture. The data presented in this submission refer to the SIMFIP measurements and analyses of the stimulation tests conducted on the 164 ft (50 m) notch of the Sanford Underground Research Facility (SURF), during the EGS-Collab test 1. In addition to the datafiles, there is the draft of a manuscript submitted to Geophysical Research Letters (GRL).

These data and test descriptions are from a set of primarily tensile hydraulic-fracture stimulations in wells E2-TC and E2-TU and a subsequent chilled water circulation test conducted by injecting in well E2-TU on the 4100 level of the Sandford Underground Research Facility (SURF). Stimulations were carried out between April and May of 2022. The thermal circulation test ran semi-continuously from May 19 through August 26, 2022, though chilled water injection began on June 3. More information about the test, rationale, and processing of data is available on the EGS Collab project page, which is linked below.

Stimulation data from Experiment 1 of EGS Collab, which occurred on the 4850 ft level of the Sanford Underground Research Facility (SURF). A detailed description of the stimulation data is provided in the StimulationDataNotes.docx and is also available on the EGS Collab Wiki. A Meta Data Cheat Sheet, which describes all of the channels in the Raw CSV files, is available as well. Note that this cheat sheet is a comprehensive meta data descriptor and channels were added as the experiment evolved. This means that some columns may not be populated in early data. Additionally, we have included the chat logs from these experiments. The experiments were broadcast over teleconferencing software and real-time data displays were available to remote observers. The logs contain important observations from those personnel performing the experiment and the remote contributors. Finally, we have included summary and individual plots of all of the data for the user to compare to.

This submission contains datasets and a final manuscript associated with a project simulating carbon dioxide push-pull into a conjugate fault system modeled after Dixie Valley- sensitivity analysis of significant parameters and uncertainty prediction by data-worth analysis. Datasets include: (1) Forward simulation runs of standard cases (push & pull phases), (2) Local sensitivity analyses (push & pull phases), and (3) Data-worth analysis (push & pull phases).

These data and test descriptions comprise a chilled circulation test conducted at the 164' fracture in the EGS Collab Experiment 1 testbed on the 4850 ft level of the Sanford Underground Research Facility. Descriptions of the meta data, design drawings for the flow testing system, and evaluation of the thermistor data are provided here. The test ran from April 2019 through early March of 2020, when testing was concluded at the experiment 1 site. These data are are complementary to the stimulation data provided in another submission which is linked below (i.e. stimulation at the 164' notch). More information about the test itself as well as the rationale and process of data processing is available on the EGS Collab Experiment 1 Long Term Circulation Test wiki page which is also linked below.

A corrigendum was submitted to the journal of Geothermics on our article "Environmentally friendly, rheoreversible, hydraulic-fracturing fluids for enhanced geothermal systems" Shao et al Geothermics 58 (2015) 22-31. In the original article some permeability values were underestimated, in particular, for rock samples fractured by the stimuli-responsive fracking fluid (PAA-CO2). In addition, effective pressures were determined to be lower for three control experiments (deionized water-carbon dioxide, DIW-CO2). Therefore, we revised values of permeability and effective pressure as well as performed additional lab-scale stimulation experiments under identical conditions to further verify/update the deductions presented in the discussion section. This is the reason for the additional data introduced in the below Table 1 (grey color). The authors regret the following inadvertent errors and corresponding modifications. These modifications do not change the scientific conclusions of the article.

A corrigendum was submitted to the journal of Geothermics on our article "Environmentally friendly, rheoreversible, hydraulic-fracturing fluids for enhanced geothermal systems" Shao et al Geothermics 58 (2015) 22-31. In the original article some permeability values were underestimated, in particular, for rock samples fractured by the stimuli-responsive fracking fluid (PAA-CO2). In addition, effective pressures were determined to be lower for three control experiments (deionized water-carbon dioxide, DIW-CO2). Therefore, we revised values of permeability and effective pressure as well as performed additional lab-scale stimulation experiments under identical conditions to further verify/update the deductions presented in the discussion section. This is the reason for the additional data introduced in the below Table 1 (grey color). The authors regret the following inadvertent errors and corresponding modifications. These modifications do not change the scientific conclusions of the article.