University of Illinois Urbana-Champaign

Monitoring microseismic activity in core samples encased in core flooding apparatus subjected to confining and pore pressures

Liu, Xinyang

Content Files
LIU-THESIS-2017.pdf

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https://hdl.handle.net/2142/97511

Description

Title
Monitoring microseismic activity in core samples encased in core flooding apparatus subjected to confining and pore pressures
Author(s)
Liu, Xinyang
Issue Date
2017-04-27
Director of Research (if dissertation) or Advisor (if thesis)
Popovics, John S.
Department of Study
Civil & Environmental Eng
Discipline
Civil Engineering
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
M.S.
Degree Level
Thesis
Date of Ingest
2017-08-10T19:16:21Z
Keyword(s)
  • Microseismicity
  • Acoustic emission
  • Geological sequestration
Abstract
Geological sequestration of CO2 is considered as one of the most promising technologies to mitigate global warming. The process of CO2 injection and storage in the porous sandstones, however, may be accompanied with an increase in microseismic activity. In order to better understand the causes of microseismic events detected during and after CO2 injection, a sensitive, reliable and consistent data acquisition system was developed in the present study for monitoring microseismic (acoustic emission or AE) events emanating from rock samples tested in the core flooding apparatus at the Illinois State Geological Survey (ISGS) laboratory. Several types of sandstone and PVC core samples with various treatments were prepared and evaluated. These samples were subjected to loading/unloading patterns of confining and pore pressures, so as to simulate the environment of underground sandstone formations for carbon storage. The detected AE events were synchronized with the applied pressure profiles to show the temporal clustering of events. A simple one-dimensional localization model was built to determine the spatial variations of event source locations along the axis of the core sample. Criteria for noise elimination and for event characterization were proposed. Results were generally satisfactory and repeatable. Very few AE events were detected from solid PVC and sandstone samples. Many more AE events were detected from the fractured samples with visible damage, and the localized event source locations determined by the model were consistent with the induced cracking positions. When the sample was subjected to a combination of confining and pore pressures, AE event clustering was observed when the net pressure, defined as the differential pressure between confining and pore pressures, increased.
Graduation Semester
2017-05
Type of Resource
text
Permalink
http://hdl.handle.net/2142/97511
Copyright and License Information
Copyright 2017 Xinyang Liu

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Graduate Dissertations and Theses at Illinois PRIMARY
Graduate Theses and Dissertations at Illinois
Dissertations and Theses - Civil and Environmental Engineering