The Library
Controls on the hydraulic fracture propagation across sealing faults and natural fractures : a numerical study
Tools
Sarmadi, Nima (2023) Controls on the hydraulic fracture propagation across sealing faults and natural fractures : a numerical study. PhD thesis, University of Warwick.
PDF
WRAP_Theses_Sarmadi_2023.pdf - Submitted Version Embargoed item. Restricted access to Repository staff only until 22 November 2025. Contact author directly, specifying your specific needs. - Requires a PDF viewer. Download (13Mb) |
Official URL: http://webcat.warwick.ac.uk/record=b3985957
Abstract
The success of hydraulic fracturing operations in rocks is conditional to the development of a vast man-made network of fractures in low-permeable rocks to maximise the extraction of hydrocarbons resources or exploitation of geothermal energy from targeted reservoirs. The hydraulic fracture (HF) propagation path can be affected by the existence of natural fractures, fault zones, and smear-type material heterogeneities, so the efficiency of the operations may decrease. Therefore, it is important to identify the relevant factors that control the HF propagation behaviour in such heterogeneous reservoirs. This research aims to identify the factors influencing the propagation path of the HF using numerical modelling. The computational tool for modelling the HF propagation in heterogeneous rocks should observe the nonlinear hydro-mechanical behaviour of fracturing rocks, capture mixed-mode cracking, and model shear failure in geo-materials under compressive shearing stresses. The phase-field method, which is based on the variational principle in the context of finite element method (FEM), is employed to model HFs in saturated porous rocks. The evolution of deformation and pore fluid pressure fields are modelled using a fully coupled hydro-mechanical model in a geometrically nonlinear computational code implemented in MATLAB. The phase-field HF model is enhanced computationally by using a mesh refinement strategy, sensitive to the input material parameters, to predict the propagation path affected by the HF front and the existing heterogeneities such as natural fractures/faults. Conducting numerical simulations can provide useful information on the effects of natural heterogeneities on the HF propagation in reservoirs with a lower cost compared to the field investigations or experimental works. Extensive parametric and stochastic analyses are conducted employing the developed model in this research to investigate the effects of natural fractures and sealing faults on the possible diversion of the HF propagation from its original path. It is found out in this research that the permeability of the natural fault/fracture and the state of in-situ stresses play are the main controls in the HF propagation process, and the injection rate for driving the HF forward, the inclination of heterogeneities with respect to the HF direction, and the geomechanical characteristics of the rock and the fault zone are the secondary important factors.
Item Type: | Thesis (PhD) | ||||
---|---|---|---|---|---|
Subjects: | T Technology > TA Engineering (General). Civil engineering (General) T Technology > TN Mining engineering. Metallurgy |
||||
Library of Congress Subject Headings (LCSH): | Hydraulic fracturing -- Mathematical models, Rock mechanics -- Mathematical models, Fracture mechanics -- Mathematical models, Phase transformations (Statistical physics), Porous materials -- Cracking, Fluid-structure interaction | ||||
Official Date: | March 2023 | ||||
Dates: |
|
||||
Institution: | University of Warwick | ||||
Theses Department: | School of Engineering | ||||
Thesis Type: | PhD | ||||
Publication Status: | Unpublished | ||||
Supervisor(s)/Advisor: | Nezhad, Mohaddesh Mousavi | ||||
Sponsors: | University of Warwick. School of Engineering ; University of Leeds | ||||
Format of File: | |||||
Extent: | xxxii, 244 pages | ||||
Language: | eng |
Request changes or add full text files to a record
Repository staff actions (login required)
View Item |