Chemically modified hydrogels to improve geothermal reservoir performance by enabling flow control via size-shifting microspheres
Abstract
Thermal short circuits, where fluids preferentially connect injection and production wells, are a leading cause of premature enthalpy decline in geothermal reservoirs. These pathways accelerate cooling, reduce effective heat transfer area, and limit reservoir lifetime. We propose a temperature-responsive hydrogel microsphere suspension as an “active tracer” that dynamically redirects flow away from cooled short-circuit channels while also tracing fluid flow via fluorescence spectroscopy. Highly idealized reservoir simulations with field-informed permeability distributions indicate that a yieldstress fluid with temperature-responsive behaviors may improve reservoir thermal lifetime by a factor of at least 24 to 59x while maintaining acceptable hydraulic performance. To develop a candidate “active” tracer intended to satisfy the assumptions of the idealized simulations, we synthesized poly(N-isopropylacrylamide) (pNIPA) microgels, characterized their swelling and rheological behavior, and conducted a large-scale laboratory experiment in an analog parallel-plate that demonstrates short-circuited flow behavior. These lab-scale results demonstrate that injected microgels clog cooled short circuits via swelling and diverted flow into hotter regions. This proof-of-concept establishes an attractive pathway for employing engineered materials to actively manage flow and extend geothermal reservoir lifetimes.
Related
- Decoupling Electronic–Ionic Transport and Catalysis Enables High‐Performance, Chemically Stable Sr‐Free Air Electrodes for High‐Temperature Solid Oxide Cells
- Surfactants for enhanced oil recovery: A critical review of mechanisms, performance, reservoir compatibility, and field applications
- Performance Evaluation on Profile Control and Flooding of QPD Thermosensitive Gel in High-Temperature and High-Salinity Reservoir of Block X
- Light Magnesium Oxide Nanosheets for Efficient Fluoride Removal from Geothermal Water: Rapid Adsorption and Mechanistic Insights
- Porous nanofibrous microspheres: synthesis approaches and applications to tissue regeneration
BibTeX
@misc{baxter2026chemically,
title = {{Chemically modified hydrogels to improve geothermal reservoir performance by enabling flow control via size-shifting microspheres}},
author = {Aaron M. Baxter and Danni Tang and Bryan H. Abdulaziz and Reeby J. Puthur and Patrick M. Fulton and Sarah Hormozi and Christopher C. Alabi and Ulrich B. Wiesner and Jefferson W. Tester and Adam J. Hawkins},
howpublished = {ChemRxiv},
year = {2026},
month = oct,
doi = {10.26434/chemrxiv.15010139/v1},
url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010139/v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - Chemically modified hydrogels to improve geothermal reservoir performance by enabling flow control via size-shifting microspheres
AU - Aaron M. Baxter
AU - Danni Tang
AU - Bryan H. Abdulaziz
AU - Reeby J. Puthur
AU - Patrick M. Fulton
AU - Sarah Hormozi
AU - Christopher C. Alabi
AU - Ulrich B. Wiesner
AU - Jefferson W. Tester
AU - Adam J. Hawkins
PY - 2026
DA - 2026/10/09
PB - ChemRxiv
DO - 10.26434/chemrxiv.15010139/v1
UR - https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010139/v1
AB - Thermal short circuits, where fluids preferentially connect injection and production wells, are a leading cause of premature enthalpy decline in geothermal reservoirs. These pathways accelerate cooling, reduce effective heat transfer area, and limit reservoir lifetime. We propose a temperature-responsive hydrogel microsphere suspension as an “active tracer” that dynamically redirects flow away from cooled short-circuit channels while also tracing fluid flow via fluorescence spectroscopy. Highly idealized reservoir simulations with field-informed permeability distributions indicate that a yieldstress fluid with temperature-responsive behaviors may improve reservoir thermal lifetime by a factor of at least 24 to 59x while maintaining acceptable hydraulic performance. To develop a candidate “active” tracer intended to satisfy the assumptions of the idealized simulations, we synthesized poly(N-isopropylacrylamide) (pNIPA) microgels, characterized their swelling and rheological behavior, and conducted a large-scale laboratory experiment in an analog parallel-plate that demonstrates short-circuited flow behavior. These lab-scale results demonstrate that injected microgels clog cooled short circuits via swelling and diverted flow into hotter regions. This proof-of-concept establishes an attractive pathway for employing engineered materials to actively manage flow and extend geothermal reservoir lifetimes.
ER -