Gunaydin-Tulu, Delal
(2022)
Self-Organization Mechanisms within Magma Driven Dyke and Hydraulic Fracture Swarms.
Doctoral Dissertation, University of Pittsburgh.
(Unpublished)
This is the latest version of this item.
Abstract
Swarm theory offers a new approach for studying the conditions that promote the formation of natural and engineered swarms of fluid-driven fractures, such as dyke swarms and hydraulic fracture swarms. Studying their emplacement mechanisms is essential in understanding the Earth’s tectonic history, which in the future can be used as an analog to explore the similar physical processes in Venus and Mars. Self-organization, one of the most fundamental characteristics of swarming behavior, can be expressed by the emergence of a natural spacing between the swarm members due to the evidence of field measurements indicating that fracture spacing is often unusually consistent in both giant dyke swarms and engineered systems. Thus, identifying the drivers that lead to emergent spacing becomes synonymous with understanding the swarming behavior mechanisms.
This study investigates the mechanisms promoting self-organization and demonstrates how the interplay of the alignment, avoidance, and attraction forces – drivers of swarming in biological systems – leads to emergent length scales governing dyke spacing. The work is given in three parts. First, experimental confirmation of complex interaction among fluid-driven fractures is presented. The results demonstrate that fractures sometimes are suppressed by their neighbors. In other cases, with the specific non-uniform spatial distribution, their interaction results in more uniform growth. Moreover, comparisons of the experimental results to the numerical model predictions show a good agreement. Second, experimental proof of concept for emergent spacing in systems with multiple fluid-driven fractures is presented. With many narrowly spaced fractures, a geometrical pattern emerges, with every third or fourth fracture growing the most extended, resulting in an emergent spacing 3.5 - 4.5 times the fracture height. Furthermore, these experiments demonstrate a tendency for multiple fractures to grow simultaneously, overturning the hypothesis that dykes should be expected to develop one at a time. Lastly, results of laboratory experiments analog to fluid flow through specific geological configurations, such as the intersection of joints with each other and with bedding contacts, are presented. These experiments open a new model of subsurface fluid transport that explains rapid transport unable to be captured by existing models.
In summary, this study confirms that for well-aligned fluid-driven fracture swarms, when the attraction force, linked to viscous energy dissipation, is balanced with the avoidance force related to stress interaction, an optimal spacing emerges scaling with the height of fractures.
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Details
| Item Type: |
University of Pittsburgh ETD
|
| Status: |
Unpublished |
| Creators/Authors: |
|
| ETD Committee: |
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| Date: |
6 September 2022 |
| Date Type: |
Publication |
| Defense Date: |
17 June 2022 |
| Approval Date: |
6 September 2022 |
| Submission Date: |
25 July 2022 |
| Access Restriction: |
2 year -- Restrict access to University of Pittsburgh for a period of 2 years. |
| Number of Pages: |
138 |
| Institution: |
University of Pittsburgh |
| Schools and Programs: |
Swanson School of Engineering > Civil and Environmental Engineering |
| Degree: |
PhD - Doctor of Philosophy |
| Thesis Type: |
Doctoral Dissertation |
| Refereed: |
Yes |
| Uncontrolled Keywords: |
Dyke Swarms, Hydraulic Fractures, Swarm Theory, Self-Organization, Hydraulic Fracture Interaction, Mechanical Model |
| Date Deposited: |
06 Sep 2022 16:26 |
| Last Modified: |
06 Sep 2024 05:15 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/43370 |
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Self-Organization Mechanisms within Magma Driven Dyke and Hydraulic Fracture Swarms. (deposited 06 Sep 2022 16:26)
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