| Title | Near-Wellbore DEM Model of Hydraulic Fracture Initiation for Utah FORGE Site |
|---|---|
| Authors | Wei FU, Branko DAMJANAC, Zorica RADAKOVIC-GUZINA, Aleta FINNILA, Robert PODGORNEY, John MCLENNAN |
| Year | 2024 |
| Conference | Stanford Geothermal Workshop |
| Keywords | Near-Wellbore Tortuosity, Cement Sheath, Perforation, Discrete Fracture Network (DFN), Enhanced Geothermal System (EGS) |
| Abstract | Three stimulation stages were performed in 2022 near the toe of well 16A(78)-32 at the Utah FORGE site, consisting of two cased-hole sections and one open-hole section. An important aspect of cased-hole completion is to perforate the well casing to establish flow paths between the wellbore and the adjacent reservoir. In the two cased-hole sections, single 20-ft long perforation clusters with six shots per foot at 60° phasing were used, along with bridge plugs for stage isolation. The placement of the perforations, together with the complex stress field resulting from subsurface in-situ stresses and stress concentrations around the wellbore and perforation tunnels, can significantly influence the near-wellbore fracture geometry, which, in turn, directly impacts fluid flow efficiency into and out of the well. Building upon field tests, we have developed numerical models for the Utah FORGE Site to explore the near-wellbore fracture geometry and fluid pressure characteristics. The numerical models use a discrete element modeling (DEM) approach to explicitly represent the well casing, cement sheath, and perforation tunnels. Numerical simulations are performed to investigate fracture initiation from perforation tunnels. The modeling results demonstrate complex fracture behaviors highlighting the competition and merging of fractures and illustrate the important roles of cement strength and discrete fracture network (DFN) in the near-wellbore growth of hydraulic fractures. |