Laboratory and discrete element study of proppant crushing and embedment and their influence on fracture conductivity
department or school: Applied Science, Faculty of
department or school: Engineering, School of (Okanagan)
data provider: DSpace
degree campus: UBCO
creator: Zheng, Wenbo
issued: 2017-12-22T19:08:51Z
issued: 2017
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: Proppants are widely used in hydraulic fracturing for unconventional resources to increase the recovery rate of hydrocarbons in the oil and gas industry. More than 55 million tonnes of proppants were supplied for hydraulic fracturing in 2015 to fracture more than 35,000 wells. During hydraulic fracturing, proppants are transported by fracturing fluids into fractures to form a permeable proppant pack, which acts as a path for hydrocarbons to flow to wellbores. When high closure stresses exist, proppants can be crushed into smaller fragments and embed into fracture surfaces, which reduces the propped fracture conductivity by decreasing the proppant pack permeability and thickness. Choosing a suitable proppant for hydraulic fracturing is key to success in recovering hydrocarbons. Compared with time-consuming laboratory tests and simplified empirical/numerical models, the discrete element method (DEM) is a natural approach for simulating proppant crushing and embedment into fracture faces. However, current DEM simulations have not considered proppant crushing under high closure stresses. In addition, the mechanical properties of different proppants have not been fully characterised thus modelling of proppants in DEM lacks verification. Moreover, DEM simulations of proppant embedment into rock surface have not been calibrated/compared with laboratory hardness tests on rock faces. Finally, the influence of proppant crushing and embedment on proppant selection has not been thoroughly studied. With these in mind, this research presents comprehensive laboratory experiments on proppant crushing which were used to calibrate discrete element models of proppant crushing and proppant embedment. Three objectives are accomplished within this research: (1) characterize the mechanical behaviour of proppant crushing and proppant embedment into fracture surfaces; (2) model proppant crushing and proppant embedment with DEM; (3) study the influence of proppant crushing and proppant embed…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/64152
note: LABORATORY AND DISCRETE ELEMENT STUDY OF PROPPANT CRUSHING AND EMBEDMENT AND THEIR INFLUENCE ON FRACTURE CONDUCTIVITY by Wenbo Zheng B.Eng., Tongji University, China, 2010 M.Eng., Tongji University, China, 2013 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in The College of Graduate Studies (Civil Engineering) THE UNIVERSITY OF BRITISH COLUMBIA (Okanagan) December 2017 © Wenbo Zheng, 2017ii The following individuals certify that they have read, and recommend to the College of Graduate Studies for acceptance, a thesis/dissertation entitled: LABORATORY AND DISCRETE ELEMENT STUDY OF PROPPANT CRUSHING AND EMBEDMENT AND THEIR INFLUENCE ON FRACTURE CONDUCTIVITY submitted by Wenbo Zheng in partial fulfilment of the requirements of the degree of Doctor of Philosophy. Dr. Dwayne D. Tannant, School of Engineering Supervisor Dr. Sumi Siddiqua, School of Engineering Supervisory Committee Member Dr. Hadi Mohammadi, School of Engineering Supervisory Committee Member Dr. Lukas Bichler, School of Engineering University Examiner Dr. Giovanni Grasselli, University of Toronto External Examiner iii Abstract Proppants are widely used in hydraulic fracturing for unconventional resources to increase the recovery rate of hydrocarbons in the oil and gas industry. More than 55 million tonnes of proppants were supplied for hydraulic fracturing in 2015 to fracture more than 35,000 wells. During hydraulic fracturing, proppants are transported by fracturing fluids into fractures to form a permeable proppant pack, which acts as a path for hydrocarbons to flow to wellbores. When high closure stresses exist, proppants can be crushed into smaller fragments and embed into fracture surfaces, which reduces the propped fracture conductivity by decreasing the proppant pack permeability and thickness. Choosing a suitable proppant for hydraulic fracturing is key to success in recovering hydrocarbons. Compared with time-consuming laboratory tests and si…
has type: Thesis/Dissertation
date issued: 2018-02
is shown at: 10.14288/1.0362394
language: eng
degree discipline: Civil Engineering
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/64152