PhD: Coupled hydro mechanics of reservoir rocks studied by quantitative in situ neutron imaging

Starting: September 2015

Understanding the hydro-mechanics of porous subsurface reservoir rocks, is key to a number of resource engineering challenges, e.g., hydrocarbon and water production and CO2 sequestration (in the first cases fluids are extracted from subsurface geologic formations and in the latter fluids are injected into the same or similar formations). These processes are poorly understood, as current experimental analyses do not adequately consider the coupled hydro-mechanical problem nor do they capture the (evolving) heterogeneity of the deformation and flow.


This project will develop new experimental approaches, based on neutron imaging, to monitor and quantify the evolution of the coupled, heterogeneous processes of deformation and fluid flow in porous rocks. This will in turn facilitate the development of more accurate, coupled hydro-mechanical modelling tools for reservoir simulation. The key tool in the research approach is in-situ neutron imaging of coupled hydro-mechanical experiments. Neutrons, being highly sensitive to hydrogen, provide the ideal probe for detecting hydrogen rich fluids (e.g., water and oils) in dense porous materials, such as rocks. The other key advantage of neutron methods, is their low interaction with many metals, which in the current project, renders the high-pressure sample confinement vessels quite transparent in neutron imaging.

Image caption: (Left) Time­‐lapse  neutron  radiographs  of  the  water  imbibition  into  a  deformed  sandstone specimen  (lower  neutron  transmission  intensity  values  are  associated  with  increased  water  (and  oil) saturation, sample width is about 35 mm). (Right a) Tracked  fluid  fronts  overlaid  on  the  final  neutron  radiograph  (colours  represent  the  initial  neutron intensity as in image to left) and (Right b) quantified local flow velocities.

 

This project will provide new insight into the coupled hydro-mechanical evolution of porous reservoir rocks during deformation; this will be in the form of quantified full-field data on heterogeneous strain-field evolution and the associated evolution in permeability. These experimental and data analysis techniques will open up new doors for wider research use of neutrons for flow/mechanical studies in the geo and engineering sciences.

 

This project involves a collaboration between the Division of solid mechanics from the University of Lund and the laboratory 3SR.

 

PI: Stephen A. Hall (visitor); Co-PI: Cino Viggiani; PhD Student: Maddi Etxegarai

 

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