1. Integrated Stress Field Estimation and Implications for Enhanced Geothermal System Development in Acoculco, Mexico
- Author
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Kruszewski M.[1, Hofmann H.[3], Alvarez F.G.[5], Bianco C.[4], Haro A.J.[5], Garduño V.H.[5], Liotta D.[4, Trumpy E.[6], Brogi A.[4, Wheeler W.[7], Bastesen E.[7], Parisio F.[8], Saengeri E.H.[1, and Publica
- Subjects
Renewable Energy, Sustainability and the Environment ,Cauchy stress tensor ,Well logging ,0211 other engineering and technologies ,Geology ,02 engineering and technology ,010502 geochemistry & geophysics ,Geotechnical Engineering and Engineering Geology ,Overburden pressure ,Enhanced geothermal system ,01 natural sciences ,Stress field ,Geothermal exploration ,021108 energy ,in-situ stress estimation ,hydraulic stimulation ,Enhanced Geothermal Systems (EGS) ,Acoculco geothermal system ,geothermal reservoir geomechanics ,Pore pressure gradient ,Petrology ,Geothermal gradient ,0105 earth and related environmental sciences - Abstract
Data gathered from two geothermal exploration wells in the Acoculco caldera, within the Trans-Mexican Volcanic Belt, indicated that temperature is high enough for economic utilization, but permeability is insufficient. Hence, heat exploitation at this location may only be possible by Enhanced Geothermal System (EGS) technologies. To evaluate the potential for EGS development, a wide range of exploration work has been carried out in the framework of the international research project GEMex. In this manuscript, we present best estimates of the in-situ stress field conditions at the site - an important, yet highly uncertain, parameter for stimulation planning. The study is based on geological data, drilling parameters, geophysical logging, laboratory measurements on collected rock samples, and statistical analyses. The in-situ stress regime of the Acoculco geothermal area can be described as transtensional with a maximum horizontal stress striking in the NE-SW direction, a pore pressure gradient of 8.73 MPa·km-1, a minimum horizontal stress gradient of 22.8 ± 3.3 MPa·km-1, a vertical stress gradient of 24.3 ± 1.5 MPa·km-1, and a maximum horizontal stress gradient of 42.9 ± 28.5 MPa·km-1. Based on the predicted stress tensor, we estimate the maximum pressure required to enhance the rock permeability and discuss the potential EGS development options for the Acoculco geothermal area.
- Published
- 2021
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