Microscopic Stress Sensitivity Analysis with In Situ SEM Study and Digital Core Deformation Simulation

Rock stress sensitivity is typically investigated macroscopically. In contrast, a new method combining in situ Scanning Electronic Microscope (SEM) study and digital core deformation simulation is developed in this paper, providing an effective way to investigate the relationship between microstruct...

Full description

Saved in:
Bibliographic Details
Main Authors: Weibo Sui, Yanan Hou, Zhilin Cheng
Format: Article
Language:English
Published: Wiley 2021-01-01
Series:Geofluids
Online Access:http://dx.doi.org/10.1155/2021/6663616
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850227188746420224
author Weibo Sui
Yanan Hou
Zhilin Cheng
author_facet Weibo Sui
Yanan Hou
Zhilin Cheng
author_sort Weibo Sui
collection DOAJ
description Rock stress sensitivity is typically investigated macroscopically. In contrast, a new method combining in situ Scanning Electronic Microscope (SEM) study and digital core deformation simulation is developed in this paper, providing an effective way to investigate the relationship between microstructural deformation and decreasing permeability. The simulation method might replace in situ SEM study under certain scenarios. First, the in situ SEM study was implemented, and the microstructure deformations of rock samples during uniaxial loading were observed and recorded. The SEM images at different stress states were analyzed by digital image correlation (DIC) technique to investigate the principles of these deformations. A deformation simulation method was correspondingly proposed. The simulation effectiveness was demonstrated by comparing the simulation and the in situ SEM study results. To validate the simulation method for the three-dimensional (3D) digital core, porosity-permeability integrated measurements under triaxial stresses were conducted to obtain macroscale data under different stress states for a tight sandstone sample. A 3D digital core was reconstructed by micro-CT imaging with the same rock sample. Under the constraints of the measured porosity changes, the 3D digital core deformation was simulated. A series of simulated cores at different stress states were used for pore network model extraction, and the corresponding permeability was calculated. A comparison of the permeability changes of the simulation and porosity-permeability integrated measurements indicated consistently that the simulation method can characterize the 3D digital core stress sensitivity. In addition, the in situ SEM study results revealed that the throats deformed more severely than the pores by generating the pore and throat diameter frequency distributions at different stress states. Therefore, we concluded that throat deformation is more critical than pore deformation for permeability reduction.
format Article
id doaj-art-1734a7bb07ba40a596c930576ec01725
institution OA Journals
issn 1468-8115
1468-8123
language English
publishDate 2021-01-01
publisher Wiley
record_format Article
series Geofluids
spelling doaj-art-1734a7bb07ba40a596c930576ec017252025-08-20T02:04:54ZengWileyGeofluids1468-81151468-81232021-01-01202110.1155/2021/66636166663616Microscopic Stress Sensitivity Analysis with In Situ SEM Study and Digital Core Deformation SimulationWeibo Sui0Yanan Hou1Zhilin Cheng2College of Petroleum Engineering, China University of Petroleum (Beijing), Beijing 102249, ChinaCollege of Petroleum Engineering, China University of Petroleum (Beijing), Beijing 102249, ChinaCollege of Petroleum Engineering, China University of Petroleum (Beijing), Beijing 102249, ChinaRock stress sensitivity is typically investigated macroscopically. In contrast, a new method combining in situ Scanning Electronic Microscope (SEM) study and digital core deformation simulation is developed in this paper, providing an effective way to investigate the relationship between microstructural deformation and decreasing permeability. The simulation method might replace in situ SEM study under certain scenarios. First, the in situ SEM study was implemented, and the microstructure deformations of rock samples during uniaxial loading were observed and recorded. The SEM images at different stress states were analyzed by digital image correlation (DIC) technique to investigate the principles of these deformations. A deformation simulation method was correspondingly proposed. The simulation effectiveness was demonstrated by comparing the simulation and the in situ SEM study results. To validate the simulation method for the three-dimensional (3D) digital core, porosity-permeability integrated measurements under triaxial stresses were conducted to obtain macroscale data under different stress states for a tight sandstone sample. A 3D digital core was reconstructed by micro-CT imaging with the same rock sample. Under the constraints of the measured porosity changes, the 3D digital core deformation was simulated. A series of simulated cores at different stress states were used for pore network model extraction, and the corresponding permeability was calculated. A comparison of the permeability changes of the simulation and porosity-permeability integrated measurements indicated consistently that the simulation method can characterize the 3D digital core stress sensitivity. In addition, the in situ SEM study results revealed that the throats deformed more severely than the pores by generating the pore and throat diameter frequency distributions at different stress states. Therefore, we concluded that throat deformation is more critical than pore deformation for permeability reduction.http://dx.doi.org/10.1155/2021/6663616
spellingShingle Weibo Sui
Yanan Hou
Zhilin Cheng
Microscopic Stress Sensitivity Analysis with In Situ SEM Study and Digital Core Deformation Simulation
Geofluids
title Microscopic Stress Sensitivity Analysis with In Situ SEM Study and Digital Core Deformation Simulation
title_full Microscopic Stress Sensitivity Analysis with In Situ SEM Study and Digital Core Deformation Simulation
title_fullStr Microscopic Stress Sensitivity Analysis with In Situ SEM Study and Digital Core Deformation Simulation
title_full_unstemmed Microscopic Stress Sensitivity Analysis with In Situ SEM Study and Digital Core Deformation Simulation
title_short Microscopic Stress Sensitivity Analysis with In Situ SEM Study and Digital Core Deformation Simulation
title_sort microscopic stress sensitivity analysis with in situ sem study and digital core deformation simulation
url http://dx.doi.org/10.1155/2021/6663616
work_keys_str_mv AT weibosui microscopicstresssensitivityanalysiswithinsitusemstudyanddigitalcoredeformationsimulation
AT yananhou microscopicstresssensitivityanalysiswithinsitusemstudyanddigitalcoredeformationsimulation
AT zhilincheng microscopicstresssensitivityanalysiswithinsitusemstudyanddigitalcoredeformationsimulation