Poromechanics Investigation at Pore-scale Using Digital Rock Physics Laboratory

Transcription

1 Poromechanics Investigation at Pore-scale Using Digital Rock Physics Laboratory Session: Multiphysics October 3, 2 Shawn Zhang,*, Nishank Saxena 2, Patrick arthelemy, Mike Marsh, Gary Mavko 2, Tapan Mukerji 2 Visualization Sciences Group, urlington, M, US; 2 Stanford University, Stanford, C, US

2 genda Introduction Motivation Goal of study Theory pproach digital rock physics lab 3D Imaging vizo digital rock analysis Comsol simulation Results

3 etween Rock and Hard Place Is rock that hard? Quartzite Sandstone Metamorphism bout.com

4 Motivation: porous rock network Convention Sandstone Reservoir Shale Gas Reservoir, 7,x Magnification Ø 33.% - 753mD 2µm 7nm or.7µm Tight-Gas Sandstone Reservoir 7.2µm Ø % -.52mD 5µm Ø 2.57% ~.3mD 5nm

5 Motivation: porous rock network Convention Sandstone Reservoir Shale Gas Reservoir, 7,x Magnification Ø 33.% - 753mD 5µm 7nm or.7µm Important Oil and Gas Geology Hydrology 7.2µm Ø 2.57% ~.3mD 5nm

6 Motivation: porous rock network Convention Sandstone Reservoir Shale Gas Reservoir, 7,x Magnification Ø 33.% - 753mD 5µm 7nm or.7µm Complex Multiscale Multiphase Multiphysics 7.2µm Ø 2.57% ~.3mD 5nm

7 Goal: Validate Pore Filling Theory This Presentation, Validates the use of solid material filling to replace more commonly used fluid filling theory; Designs the validation framework using digital rock physics. Work in progress, Derives generic pore filling theory; Validates new theory in a similar framework with more complex physics.

8 Pore filling Theories: Substitution Equation, sat, sat Solid Solid Material Solid Solid, Empty, Fluid Substitution: rine Sand, Oil Sand, Gas Sand Solid Substitution: Heavy oil, itumen filled

9 Pore filling Theories: Substitution Equation, sat, sat Solid Solid Material Solid Solid, Empty, Fluid Substitution: Gassmann, 95 Solid Substitution: Ciz & Shapiro, sat 997

10 Solid Substitution equation sat where sat η Effective bulk modulus Porosity Dry (drained) rock bulk modulus ulk modulus of the pore-filling mineral ulk modulus of the solid matrix

11 Digital Rock Physics Lab n escape from the flat land. Edward Tufts, 98 vizo workflow 3D Image Stack Image Import and Processing 3D Volume Reconstruction Multiple Modalities, Scales or Channels Discovery Experiment Modification Registration / Fusion Enhanced Visualization Geometry Reconstruction 3D Visualization Segmentation Statistical analysis Presentation Publication Numerical Modeling FE/CFD Custom Processing, utomation Matlab, LabVIEW, Script, C++

12 3D Imaging Imaging Data Electron microscopy S/TEM tomography TEM serial sectioning FI-SEM Nanotomography Light microscopy Confocal Polish and view 3D (e.g. Robo-MET) X-ray tomography Industrial Material sciences (micro and nano) MRI Ultrasound GPR LIDR Remote Sensing Satellite Imagery

13 Reconstruction

14 Segmentation

15 Petrophysical parameters derived from image based simulation Porosity.68 Permeability X x -3 Darcy Permeability Y.89x -3 Darcy Permeability Z.57x -3 Darcy

16 Mesh reconstruction & Comsol C oundary conditions, Normal displacement at external surface with strain ^-3. Continuity of displacement and traction at pore/rock interface. Quasi-static simulation (inertial effects are negligible).

17 Different Pore-filling Material: Pressure sat Different (Pa).x.4x 2.8x 3.2x 4.6x 5 2.x 6 2.4x 7 2.8x 8 3.2x

18 Different Pore-filling Material: Strain sat Different (Pa).x.4x 2.8x 3.2x 4.6x 5 2.x 6 2.4x 7 2.8x 8 3.2x

19 Different Pore-filling Material: Validation sat Different (Pa).x.4x 2.8x 3.2x 4.6x 5 2.x 6 2.4x 7 2.8x 8 3.2x Saturated ulk Modulus (GPa) Finite Element Simulation Present Theoretical Work pproximate Ciz and Shapiro (27) HS Upper ound HS Lower ound Pore Solid ulk Modulus (GPa)

20 Concluding remarks theoretical rock pore material substitution model is validated with a digital rock physics framework. We are working on, Derives generic pore filling theory; Validate it in a similar framework but with more complex physics, e.g., shear traction, pseudo fluid structure interaction, etc. Solid Solid pplied Stress Deformed body Reference body Internal traction Stress to maintain P P Empty P P Solid