| Title | Coupled Hydro-Mechanical Back-Analysis of Circulation Program at FORGE in July of 2023 |
|---|---|
| Authors | Zorica RADAKOVIC-GUZINA, Branko DAMJANAC, Wei FU, Aleta FINNILA, Rob PODGORNEY, John MCLENNAN |
| Year | 2024 |
| Conference | Stanford Geothermal Workshop |
| Keywords | Circulation test, Utah FORGE, Enhanced Geothermal Systems (EGS), numerical modeling, lattice method, back-analysis |
| Abstract | In April of 2022, three stages of stimulation were carried out near the toe of well 16A(78)-32 at the Utah FORGE site. During the stimulations, pumping pressure, pumping rate, and microseismic events were recorded. The locations of microseismic events extended more than 100 m above well 16A(78)-32. Well 16B(78)-32 was drilled 100 m above the highly deviated lateral of well 16A(78)-32. In July of 2023, a circulation program was conducted between the two wells. The aim was to implement low-rate injection to interrogate the reservoir between the injection well and the production well, 16A(78)-32 and 16B(78)-32, respectively; assess the effect of reservoir stimulation in April of 2022; and determine the partitioning of flow between the three stimulation stages. Consequently, the circulation testing was designed to use low injection rates to limit the creation of new hydraulic fractures. Back analysis of the circulation test was carried out using a coupled hydro-mechanical model based on the discrete element method (DEM). The objective of the modeling was to interpret the state of the reservoir by matching the recorded injection pressures at well 16A(78)-32. The model includes an explicit representation of the discrete fracture network (DFN). Some DFN fractures were generated to match the observed microseismic event locations, while the majority were generated stochastically. |