Understanding the Hydromechanical Behavior of a Fault Zone From Transient Surface Tilt and Fluid Pressure Observations at Hourly Time Scales - Archive ouverte HAL Access content directly
Journal Articles Water Resources Research Year : 2017

Understanding the Hydromechanical Behavior of a Fault Zone From Transient Surface Tilt and Fluid Pressure Observations at Hourly Time Scales

(1) , (1) , (1) , (2) , (3) , (1) , (1)
1
2
3
Jonathan Schuite
Olivier Bour
  • Function : Author
Nicolas Lavenant
  • Function : Author
  • PersonId : 944612
Philippe Davy

Abstract

Flow through reservoirs such as fractured media is powered by head gradients which also generate measurable poroelastic deformation of the rock body. The combined analysis of surface deformation and subsurface pressure provides valuable insights of a reservoir's structure and hydromechan-ical properties, which are of interest for deep-seated CO 2 or nuclear waste storage for instance. Among all surveying tools, surface tiltmeters offer the possibility to grasp hydraulically induced deformations over a broad range of time scales with a remarkable precision. Here we investigate the information content of transient surface tilt generated by the pressurization a kilometer scale subvertical fault zone. Our approach involves the combination of field data and results of a fully coupled poromechanical model. The signature of pressure changes in the fault zone due to pumping cycles is clearly recognizable in field tilt data and we aim to explain the peculiar features that appear in (1) tilt time series alone from a set of four instruments and 2) the ratio of tilt over pressure. We evidence that the shape of tilt measurements on both sides of a fault zone is sensitive to its diffusivity and its elastic modulus. The ratio of tilt over pressure predominantly encompasses information about the system's dynamic behavior and extent of the fault zone and allows separating contributions of flow in the different compartments. Hence, tiltmeters are well suited to characterize hydromechanical processes associated with fault zone hydrogeology at short time scales, where spaceborne surveying methods fail to recognize any deformation signal.
Fichier principal
Vignette du fichier
Schuite_et_al-2017-Water_Resources_Research.pdf (3.81 Mo) Télécharger le fichier
Origin : Publisher files allowed on an open archive
Loading...

Dates and versions

insu-01674282 , version 1 (02-01-2018)

Identifiers

Cite

Jonathan Schuite, Laurent Longuevergne, Olivier Bour, Thomas J. Burbey, Fredrerick Boudin, et al.. Understanding the Hydromechanical Behavior of a Fault Zone From Transient Surface Tilt and Fluid Pressure Observations at Hourly Time Scales. Water Resources Research, 2017, 53 (12), pp.10558-10582. ⟨10.1002/2017WR020588⟩. ⟨insu-01674282⟩
112 View
241 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More