Snowmass 2021 Topical Report on Synergies in Research at Underground Facilities

This is a Snowmass 2021 Topical Report for the Underground Facilities and Infrastructure Frontier on Synergies in Research at Underground Facilities: A broad range of scientific and engineering research is possible in underground laboratories, beyond the physics-focused activities described in the other Underground Facilities and Infrastructure Topical Reports. These areas of research include nuclear astrophysics, geology, geoengineering, gravitational wave detection, biology, and perhaps soon quantum information science. This UF Topical Report will survey those other scientific and engineering research activities that share interest in research-orientated Underground Facilities and Infrastructure. In most cases the breadth and depth of research aims is too large to cover in completeness and references to surveys or key documents for those fields are provided after introductory summaries. Additional attention is then given to shared, similar, and unique needs of each research area with respect to the broader underground research community's Underground Facilities and Infrastructure needs. Where potential conflicts of usage type, site, or duration might arise, these are identified.Comment: Snowmass 2021 Topical Report (UF5

Deep Underground Science and Engineering Laboratory - Preliminary Design Report

The DUSEL Project has produced the Preliminary Design of the Deep Underground Science and Engineering Laboratory (DUSEL) at the rehabilitated former Homestake mine in South Dakota. The Facility design calls for, on the surface, two new buildings - one a visitor and education center, the other an experiment assembly hall - and multiple repurposed existing buildings. To support underground research activities, the design includes two laboratory modules and additional spaces at a level 4,850 feet underground for physics, biology, engineering, and Earth science experiments. On the same level, the design includes a Department of Energy-shepherded Large Cavity supporting the Long Baseline Neutrino Experiment. At the 7,400-feet level, the design incorporates one laboratory module and additional spaces for physics and Earth science efforts. With input from some 25 science and engineering collaborations, the Project has designed critical experimental space and infrastructure needs, including space for a suite of multidisciplinary experiments in a laboratory whose projected life span is at least 30 years. From these experiments, a critical suite of experiments is outlined, whose construction will be funded along with the facility. The Facility design permits expansion and evolution, as may be driven by future science requirements, and enables participation by other agencies. The design leverages South Dakota's substantial investment in facility infrastructure, risk retirement, and operation of its Sanford Laboratory at Homestake. The Project is planning education and outreach programs, and has initiated efforts to establish regional partnerships with underserved populations - regional American Indian and rural populations

Introduction: Objectives, Strategy, Operations, Shipboard Analytical Procedures, and Explanatory Notes of Deep Sea Drilling Project Leg 54

The Pacific phase of IPOD ocean crust drilling was initiated with Leg 54, the region targeted for study by the Ocean Crust Panel being survey area PT-4 (Figure 1) (and Plate 1 [in back pocket]) north of the Siqueiros fracture zone on the western flank of the East Pacific Rise (EPR). The original purpose of this leg was to establish a type section for fast-spreading, nonrifted crust by direct sampling with stratigraphic control. We anticipated that this section would serve, in part, as a standard of comparison for other type sections, such as the Mid-Atlantic Ridge (MAR). [NOT CONTROLLED OCR

The EGS Collab Project – Summaries of Experiments 2 and 3: Experiments at 1.25 km depth at the Sanford Underground Research Facility

The EGS Collab project performed well-monitored rock stimulation and flow tests at the 10-m scale in an underground research laboratory to inform challenges in implementing enhanced geothermal system (EGS) technology. This project, supported by the US Department of Energy, gathered data and observations from the field tests and compared these to simulation results to understand processes and to build confidence in numerical modeling of the processes. The project consisted of 3 Experiments, each comprising test and testbed design, many individual tests, numerical simulation, and analysis. The Experiments were performed in two deep underground testbeds at the Sanford Underground Research Facility (SURF) in Lead, South Dakota. Field experiments are now complete, significant data sets have been collected and analyzed, and some analysis continues. Experiments using underground test facilities have many advantages in that they allow: • Three-dimensional characterization of the stimulated volume by complementary geophysical methods surrounding the experiment • Using techniques that are currently not applicable under geothermal condition to provide processes insight • Comprehensive tracer testing and detailed characterization of complex fluid movements • Understanding the geometry of the stimulated network at the meso-scale and its implications for effective fracture surface area, rock block size, and heat exchange. Underground testing has its own set of complications, however, which affect the ability to perform tests as desired and affect the experiment results. Included here are the inability to flow at desired injection rates due to stress gradients caused by drift cooling, and the need to strongly limit induced seismicity because the distance to people and equipment. Experiment 1 examined hydraulic fracturing at a depth of 1.5 km in a well-characterized phyllite. Eight subhorizontal boreholes were used in this Experiment. Geophysical monitoring instrumentation was deployed in six boreholes to monitor stimulation events and flow tests. The other two boreholes were used to perform and carefully measure water injection and production. More than a dozen stimulations and nearly one year of flow tests in the testbed were performed. Detailed observations of processes occurring during stimulation and dynamic flow tests were collected and analyzed. Flow tests using ambient-temperature and chilled water were performed with intermittent tracer tests to examine system behavior. We achieved adaptive control of the tests using close monitoring of rapidly disseminated data and near-real-time simulation. Numerical simulation was critical in answering key experimental design questions, forecasting fracture behavior, and analyzing results. We were successful in performing many simulations in near-real-time in conjunction with the field experiments, with more detailed simulations performed later. Experiment 2 was intended to examine hydraulic shearing of natural fractures at a depth of 1.25 km in amphibolite. The stresses, rock type, and fracture conditions are different than in Experiment 1. The testbed consists of 9 boreholes, in addition to 2 exploratory characterization boreholes. Four boreholes drilled as two fans of 2 monitoring holes contained grouted-in monitoring sensors. The remaining five open boreholes drilled in a five-spot pattern were adaptively used for injection, production, and monitoring. Approximately five fracture set orientations were encountered in the testbed along with a low-stress rhyolite sill at 35 m below the access drift in exploratory well TV4100. The testbed was designed to optimize the potential for shear stimulation while also avoiding the low-stress rhyolite. Experiment 2 focused on stimulating a fracture in the most likely orientation to shear, however shear stimulation did not occur probably due to cementation from natural secondary mineralization. Other fracture sets encountered were also cemented and had orientations less likely to shear. Experiment 3 consisted of several stimulations in the same testbed as Experiment 2 allowing different stimulation approaches including ramped-rate injection, rapid injection, and oscillating-pressure injection. Ultimately these methods created hydraulic fractures, one of which was used for a medium-duration cold water injection test. The major findings of the EGS Collab Project include: 1. Significant shear stimulation did not occur during our stimulation attempts. Shear stimulation may occur but under a limited set of conditions not encountered. 2. Our stimulations resulted in hydraulic fractures that required hydraulic propping. Pumping at pressures exceeding the minimum principal stress may not be feasible in an enhanced geothermal system. 3. The systems we generated were complex hydraulic fracture/natural fracture systems, and these systems changed over time in response to applied pressures and flowrates and to unknown stimuli. 4. The project attempted alternative stimulation methods, which did not provide significant flow improvement. 5. Thermal breakthrough was not achieved as designed, most likely because flow to production boreholes was not adequate. 6. The combination of geophysical tools used provided excellent understanding of many important processes. 7. Microearthquakes (MEQs) didn’t necessarily identify flow paths. 8. Engineering tools bounding expected seismicity are needed. This report provides a summary of tests and analyses performed for EGS Collab Experiment 2 (Shear Stimulation in Testbed 2) and Experiment 3 (Alternative Stimulation methods). Much of the EGS Collab work has been published in journals and conference papers, presented in conferences, included in written reports, and submitted in data sets to the Geothermal Data Repository (GDR). The entirety of these written works is included as an appendix to this report, and this report serves as a summary and framework pointing to these published papers, presentations, and reports