Production-Induced Subsidence at the Los Humeros Geothermal Field Inferred from PS-InSAR

Eszter Békési,Jan-Diederik Van Wees,Damien Bonté,Jon Limberger,Peter A Fokker,Joana E Martins

doi:10.1155/2019/2306092

Eszter Békési, Jan-Diederik Van Wees + Show 4 more

Open Access

https://doi.org/10.1155/2019/2306092

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Journal: Geofluids	Publication Date: Jun 17, 2019
Citations: 16	License type: CC BY 4.0

Affiliation: Utrecht University, Delft University of Technology

Abstract

Surface deformation due to fluid extraction can be detected by satellite-based geodetic sensors, providing important insights on subsurface geomechanical properties. In this study, we use Differential Interferometric Synthetic Aperture Radar (DInSAR) observations to measure ground deformation due to fluid extraction at the Los Humeros Geothermal Field (Puebla, Mexico). Our main goal is to reveal the pressure distribution in the reservoir and to identify reservoir compartmentalization, which can be important aspects for optimizing the production of the field. The result of the PS-InSAR (Persistent Scatterer by Synthetic Aperture Radar Interferometry) analysis shows that the subsidence at the LHGF was up to 8 mm/year between April 2003 and March 2007, which is small relative to the produced volume of5×106 m3/year. The subsidence pattern indicates that the geothermal field is controlled by sealing faults separating the reservoir into several blocks. To assess if this is the case, we relate surface movements with volume changes in the reservoir through analytical solutions for different types of nuclei of strain. We constrain our models with the movements of the PS points as target observations. Our models imply small volume changes in the reservoir, and the different nuclei of strain solutions differ only slightly. These findings suggest that the pressure within the reservoir is well supported and that reservoir recharge is taking place.

Highlights

A good understanding of reservoir processes and properties is crucial for optimizing subsurface operations
We show the first results of the PS-InSAR (Persistent Scatterer by Synthetic Aperture Radar Interferometry) time series over the Los Humeros Geothermal Field (LHGF)
The geothermal field is located at high altitudes inside the Los Humeros caldera

Summary

Introduction

A good understanding of reservoir processes and properties is crucial for optimizing subsurface operations. Uncertainty in future production and potential risks such as induced seismicity can be reduced using detailed information about the mechanical and hydraulic properties of the reservoir and its surroundings These properties affect the ground surface movements induced by subsurface activities. Numerous studies have applied the DInSAR technique and modeled the source of deformation associated with the exploitation of subsurface resources These models most commonly relate surface deformation to subsurface extraction or injection processes through so-called influence functions that are based on analytical solutions for different nuclei of strain. The main goal of this study is to have a better understanding on the subsurface processes at the LHGF based on surface movements. The LHGF is a superhot geothermal system connected to the Los Humeros caldera complex located in the eastern sector of the Trans-Mexican Volcanic Belt (Figure 1). Neotectonic deformation of the caldera floor is recorded based on field observations, associated with movements along the inner-caldera faults due to recent/active resurgence processes [11]

Interferometric Synthetic Aperture Radar Monitoring

Subsidence Modeling

Discussion and Conclusions