arXiv subjects

Ryan Schultz

Publications and source records attributed to Ryan Schultz.

3 recordsLinked to original sources

arXiv2020

Low-magnitude Seismicity with a Downhole Distributed Acoustic Sensing Array -- examples from the FORGE Geothermal Experiment

We show the capabilities of a downhole Distributed Acoustic Sensing (DAS) array in detecting, locating and characterizing low-magnitude earthquakes occurring in the vicinity of the Frontier Observatory for Research in Geothermal Energy (FORGE) site in Utah. 10.5 days of continuous data were acquired in a monitoring well at the FORGE geothermal site during the initial stimulation of an Enhanced Geothermal System in April-May 2019. Earthquake activity beneath Mineral Mountains, Utah also occurred within 10 km of the FORGE monitoring well. During the experiment, four events from those areas were cataloged by the University of Utah Seismograph Stations. Our processing of DAS data, including template matching, finds 82 earthquakes during that period, of which 16 are visible on the regional network. The magnitude of completeness obtained by DAS processing is better by at least M=0.5 than the dense surface array around the FORGE site. While a single vertical DAS array is limited in terms of event location due to its azimuthal ambiguity, multiple DAS wells or a combination of a downhole array with surface stations or near-surface horizontal DAS could jointly resolve locations. All detected events probably originated from the two active source areas and can be clustered into several distinct families.

physics.geo-ph↗

arXiv2019

Frictional Stabilities on Induced Earthquake Fault Planes at Fox Creek, Alberta: A Pore Fluid Pressure Dilemma

Earthquakes induced during hydraulic fracturing operations have occurred in a number of locales. However, in-situ studies aimed to discern the triggering mechanism remains exclusively statistical in their nature. Here, we calculate the fault slip-tendencies of eleven hydraulic fracturing induced earthquakes in a historically aseismic area using a recently constructed quantitative model for in-situ stresses. It is shown that the ambient pore pressures of the nearby Duvernay unconventional reservoirs can provide enough Pf triggering fault movement. The local fluid pressures acting on the fault could readily be increased above the critical value if a hydraulic connection exists between the fault and a propagating hydraulic fracture. The critical pressures necessary to induce slip, is estimated using a probabilistic model that incorporates uncertainties of stress and fault mechanical properties. These critical pressures are greater than expected hydrostatic pressure but less the pore pressures of nearby unconventional reservoirs.

physics.geo-ph↗

arXiv2012

Overview of the LBNE Neutrino Beam

The Long Baseline Neutrino Experiment (LBNE) will utilize a neutrino beamline facility located at Fermilab. The facility is designed to aim a beam of neutrinos toward a detector placed at the Deep Underground Science and Engineering Laboratory (DUSEL) in South Dakota. The neutrinos are produced in a three-step process. First, protons from the Main Injector hit a solid target and produce mesons. Then, the charged mesons are focused by a set of focusing horns into the decay pipe, towards the far detector. Finally, the mesons that enter the decay pipe decay into neutrinos. The parameters of the facility were determined by an amalgam of the physics goals, the Monte Carlo modeling of the facility, and the experience gained by operating the NuMI facility at Fermilab. The initial beam power is expected to be ~700 kW, however some of the parameters were chosen to be able to deal with a beam power of 2.3 MW.

physics.acc-ph↗