scholarly journals Triggering of the Pohang, Korea, Earthquake (Mw 5.5) by enhanced geothermal system stimulation

2021 ◽  
Author(s):  
WL Ellsworth ◽  
D Giardini ◽  
John Townend ◽  
S Ge ◽  
T Shimamoto
Keyword(s):  
High Pressure ◽  
Tectonic Stress ◽  
General Nature ◽  
Geothermal System ◽  
Enhanced Geothermal System ◽  
Well Drilling ◽  
Definitive Evidence ◽  
The Republic ◽  
Local Geology ◽  
High Pressure Injection

© 2019 Seismological Society of America. All rights reserved. On the afternoon of 15 November 2017, the coastal city of Pohang, Korea, was rocked by a magnitude 5.5 earthquake (Mw, U.S. Geological Survey). Questions soon arose about the possible involvement in the earthquake of the Republic of Korea's first enhanced geothermal system (EGS) project because the epicenter of the earthquake was located near the project's drill site. The Pohang EGS project was intended to create an artificial geothermal reservoir within low-permeability crystalline basement by hydraulically stimulating the rock to form a connected network of fractures between two wells, PX-1 and PX-2, at a depth of ∼4 km. Forensic examination of the tectonic stress conditions, local geology, well drilling data, the five high-pressure well stimulations undertaken to create the EGS reservoir, and the seismicity induced by injection produced definitive evidence that earthquakes induced by high-pressure injection into the PX-2 well activated a previously unmapped fault that triggered the Mw 5.5 earthquake. Important lessons of a general nature can be learned from the Pohang experience and can serve to increase the safety of future EGS projects in Korea and elsewhere.

scholarly journals Triggering of the Pohang, Korea, Earthquake (Mw 5.5) by Enhanced Geothermal System Stimulation

2019 ◽  
Author(s):  
William L. Ellsworth ◽  
Domenico Giardini ◽  
John Townend ◽  
Shemin Ge ◽  
Toshihiko Shimamoto
Keyword(s):  
High Pressure ◽  
Tectonic Stress ◽  
General Nature ◽  
Geothermal System ◽  
Enhanced Geothermal System ◽  
Well Drilling ◽  
Definitive Evidence ◽  
The Republic ◽  
Local Geology ◽  
High Pressure Injection

ABSTRACT On the afternoon of 15 November 2017, the coastal city of Pohang, Korea, was rocked by a magnitude 5.5 earthquake (Mw, U.S. Geological Survey). Questions soon arose about the possible involvement in the earthquake of the Republic of Korea’s first enhanced geothermal system (EGS) project because the epicenter of the earthquake was located near the project’s drill site. The Pohang EGS project was intended to create an artificial geothermal reservoir within low‐permeability crystalline basement by hydraulically stimulating the rock to form a connected network of fractures between two wells, PX‐1 and PX‐2, at a depth of ∼4  km. Forensic examination of the tectonic stress conditions, local geology, well drilling data, the five high‐pressure well stimulations undertaken to create the EGS reservoir, and the seismicity induced by injection produced definitive evidence that earthquakes induced by high‐pressure injection into the PX‐2 well activated a previously unmapped fault that triggered the Mw 5.5 earthquake. Important lessons of a general nature can be learned from the Pohang experience and can serve to increase the safety of future EGS projects in Korea and elsewhere.

scholarly journals Triggering of the Pohang, Korea, Earthquake (Mw 5.5) by enhanced geothermal system stimulation

2021 ◽  
Author(s):  
WL Ellsworth ◽  
D Giardini ◽  
John Townend ◽  
S Ge ◽  
T Shimamoto
Keyword(s):  
High Pressure ◽  
Tectonic Stress ◽  
General Nature ◽  
Geothermal System ◽  
Enhanced Geothermal System ◽  
Well Drilling ◽  
Definitive Evidence ◽  
The Republic ◽  
Local Geology ◽  
High Pressure Injection

© 2019 Seismological Society of America. All rights reserved. On the afternoon of 15 November 2017, the coastal city of Pohang, Korea, was rocked by a magnitude 5.5 earthquake (Mw, U.S. Geological Survey). Questions soon arose about the possible involvement in the earthquake of the Republic of Korea's first enhanced geothermal system (EGS) project because the epicenter of the earthquake was located near the project's drill site. The Pohang EGS project was intended to create an artificial geothermal reservoir within low-permeability crystalline basement by hydraulically stimulating the rock to form a connected network of fractures between two wells, PX-1 and PX-2, at a depth of ∼4 km. Forensic examination of the tectonic stress conditions, local geology, well drilling data, the five high-pressure well stimulations undertaken to create the EGS reservoir, and the seismicity induced by injection produced definitive evidence that earthquakes induced by high-pressure injection into the PX-2 well activated a previously unmapped fault that triggered the Mw 5.5 earthquake. Important lessons of a general nature can be learned from the Pohang experience and can serve to increase the safety of future EGS projects in Korea and elsewhere.

scholarly journals Well-Placement Optimization in an Enhanced Geothermal System Based on the Fracture Continuum Method and 0-1 Programming

Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 709 ◽  
Author(s):  
Liming Zhang ◽  
Zekun Deng ◽  
Kai Zhang ◽  
Tao Long ◽  
Joshua Desbordes ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Optimization Method ◽  
Geothermal System ◽  
Enhanced Geothermal System ◽  
Fractured Reservoir ◽  
Well Placement ◽  
Well Drilling ◽  
Thermal Reservoir ◽  
Placement Optimization ◽  
Well Placement Optimization

The well-placement of an enhanced geothermal system (EGS) is significant to its performance and economic viability because of the fractures in the thermal reservoir and the expensive cost of well-drilling. In this work, a numerical simulation and genetic algorithm are combined to search for the optimization of the well-placement for an EGS, considering the uneven distribution of fractures. The fracture continuum method is used to simplify the seepage in the fractured reservoir to reduce the computational expense of a numerical simulation. In order to reduce the potential well-placements, the well-placement optimization problem is regarded as a 0-1 programming problem. A 2-D assumptive thermal reservoir model is used to verify the validity of the optimization method. The results indicate that the well-placement optimization proposed in this paper can improve the performance of an EGS.

scholarly journals Performance of Hybrid Single Well Enhanced Geothermal System and Solar Energy for Buildings Heating

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2473
Author(s):  
Yujiang He ◽  
Xianbiao Bu
Keyword(s):  
Solar Energy ◽  
Service Life ◽  
Heating System ◽  
Hydrothermal Systems ◽  
Geothermal System ◽  
Heat Output ◽  
Enhanced Geothermal System ◽  
Geothermal Heat ◽  
Hybrid Heating ◽  
Single Well

The energy reserves in hot dry rock and hydrothermal systems are abundant in China, however, the developed resources are far below the potential estimates due to immature technology of enhanced geothermal system (EGS) and scattered resources of hydrothermal systems. To circumvent these problems and reduce the thermal resistance of rocks, here a shallow depth enhanced geothermal system (SDEGS) is proposed, which can be implemented by fracturing the hydrothermal system. We find that, the service life for SDEGS is 14 years with heat output of 4521.1 kW. To extend service life, the hybrid SDEGS and solar energy heating system is proposed with 10,000 m2 solar collectors installed to store heat into geothermal reservoir. The service life of the hybrid heating system is 35 years with geothermal heat output of 4653.78 kW. The novelty of the present work is that the hybrid heating system can solve the unstable and discontinuous problems of solar energy without building additional back-up sources or seasonal storage equipment, and the geothermal thermal output can be adjusted easily to meet the demand of building thermal loads varying with outside temperature.

Sign in / Sign up

Export Citation Format

Share Document