EGSim

Surrogate-Based Digital Twin for Subsurface EGS Thermal & Energy Prediction

Production horizon (years)
Well configuration
450 ft
120°
90 ft
1350
No. of fractures ⌈3160ft of stimulated well / spacing between fractures (ft)⌉ 36
Total flow rate
bbl/day
48,600
bbl/min
33.75
l/s
89.4
gal/min
8,925
Display in:
Predicted temperature
Well geometry
25-run Box-Behnken design — Numerical Simulation produced temperature (°C)
#CaseDistAngSpacFlownFTotal Q (bbl/d)x₁x₂x₃x₄0yr1yr5yr10yr15yr20yr25yr30yr
Temperature decline curves — all 25 Numerical Simulation scenarios
Surrogate-predicted decline curve vs. 3 nearest Numerical Simulation scenarios
Predicted temperature at all 7 horizons
S₁ = direct effect only  |  Sₜ = direct + all interactions  |  N=100,000 Monte Carlo samples
Sensitivity of 30-year net electrical energy (GWhe) — N=50,000 Monte Carlo
Flow/frac: 1,100–1,600 bbl/d per fracture  |  Total flow: nF × flow/frac (24,200–169,600 bbl/d)
Tornado chart — one-at-a-time impact on 30yr net energy (GWhe)
Each bar shows change from baseline (1,066 GWhe) when a single parameter moves from mid to its low/high value, all others fixed at mid.
Spacing × Distance interaction — net energy heatmap (GWhe)
Angle and flow held at mid-point. Color shows 30yr net electrical energy (GWhe). Reveals the coupled optimum.
Monte Carlo distribution — 30yr net energy across 20,000 random configurations
RSM coefficient magnitudes — current horizon (reference)
Main + quadratic
Two-factor interactions
Response surface — 30-year net electrical energy (GWhe)
(other factors held at slider values)
Calculation parameters
Injection temperature 165°F  =  73.89°C  (fixed)
Auto
Slide right to override parasitic % for all scenarios.
Auto: 20% at Qmin=24,200 bbl/d → 40% at Qmax=169,600 bbl/d (linear).
12.0%
Binary ORC cycle: converts net thermal → net electrical.
Typical range: 8% (low temp) to 16% (high temp, optimised plant).
Pelec = Q̇net,thermal × ηORC
Gross thermal power:
  Q̇gross(t) = ṁ × Cₚ × (Tprod − Tinj)
Parasitic load (pump work):
  fp = 20–40% (linear with Qtotal)
  ParMW = Q̇gross(t=0) × fp  (fixed for project life)
Parasitic (fixed MWe at t=0):
  ParMWe = Pelec,gross(t=0) × fp
Gross electrical:
  Pelec,gross(t) = Q̇gross(t) × ηORC
Net electrical:
  Pelec,net(t) = max(0, Pelec,gross(t) − ParMWe)
Cumulative electrical energy:
  Eelec = ∫₀³⁰ Pelec,net dt
Predicted energy — current slider configuration
All 25 scenarios — 30-year cumulative energy
Rank#CaseDistAngle SpacQ/fracnFQ_total (bbl/d) ṁ (kg/s)Parasitic (MWe, fixed) P_net avg (MWe) E_net 30yr (GWhe)