[CCoE Notice] Cullen College Dissertation Announcement- Mina Rezkalla (PETRO)

[Hutchinson, Inez A]

[Dissertation Defense Announcement at the Cullen College of Engineering]

The Petroleum Engineering Department Presents



Applications of Hydraulic Fracturing and Plasma Pulse Fracturing in Geothermal Reservoirs

Mina Rezkalla

April 4, 2024; 1:00 PM - 4:00 PM (CST)
Location: Tech Bridge, room erp9-104


Committee Chair:
Dr. Mohamed Soliman, Ph.D.

Committee Co-Chair:
Dr. Farouq Ali, Ph.D.

Committee Members:
Dr. Birol Dindoruk, Ph.D. | Dr. George Wong, Ph.D. | Dr. Ali Rezaei, Ph.D.



Abstract

This study discusses fracturing in geothermal reservoirs using hydraulic fracturing and plasma pulse fracturing. The hydraulic fracturing technique develops two-wing fractures that extend long inside the formation. However, the plasma fracturing technique develops multiple fractures in the area near the wellbore. The thermo-poroelasticity theory is used for modeling the hydraulic fracturing system and creating the results. In addition to the thermo-poroelastic description of the geothermal reservoir, the developed numerical model includes formulations for hydraulic fracture propagation, and fluid flow and heat transfer inside the fracture. Natural fracture deformation follows the Barton-Bandis non-linear model. The model is used to investigate three applications: (1) cold fluid injection in hot formation, (2) calculations of geothermal energy production, and (3) natural fracture activation. The results show that thermal hydraulic fractures (created using fluids colder than the geothermal formation) are wider and faster in propagation than iso-thermal fractures. In addition, less pumping fluid is needed. The length of hydraulic fractures in EGS (Enhanced Geothermal Systems) has more influence on the amount of geothermal energy production (from rock thermal conductivity of 10.7 W/(°C m)) than the number of fractures. The results also show that natural fractures can be more easily activated in tight formations than in permeable formations. For the plasma stimulation, numerical simulations and laboratory experiments are presented. Numerical work discusses the effects of rock properties on the developed fractures. Multiple releases of shock waves inside the wellbore are investigated. The impact of wellbore casing and perforation is explored against open-hole cases. The influence that the outer boundary conditions have on fracture propagation is investigated. In addition, four laboratory experiments are presented to discuss fracturing under confined and unconfined rock conditions. The experimental observation is matched with numerical simulations. Moreover, a study is presented to investigate the effect of plasma fracturing on natural fractures and to examine the plasma stimulation using nano-second pressure pulses. The results show that the number of repetitive shock waves can be optimized to develop long conductive fractures. The cased wellbore restricts the propagation of the plasma fractures, compared to the open-hole case. In addition, stress anisotropy does not appreciably affect the geometry of fractures. However, confining outer boundary stresses imposes restrictions on fracture propagation. Fracturing the confined sandstone sample requires more plasma pulses of larger energy than the unconfined sandstone. Moreover, it is easier to generate plasma fractures in limestone than in sandstone. The natural fractures can influence the configuration of the developed plasma fractures, where fractures are arrested by natural fractures and natural fractures can be activated and grow.



-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://Bug.EGR.UH.EDU/pipermail/engi-dist/attachments/20240327/6e66a2eb/attachment-0001.html 
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image001.png
Type: image/png
Size: 28058 bytes
Desc: image001.png
Url : http://Bug.EGR.UH.EDU/pipermail/engi-dist/attachments/20240327/6e66a2eb/attachment-0001.png