Experimental Study of Self-aggregating Proppants: New Approaches to Proppant Flowback Control
Lipei Fu, Guicai Zhang*, Jijiang Ge, Kaili Liao*, Haihua Pei, Jianda Li
Identifiers and Pagination:Year: 2016
First Page: 236
Last Page: 246
Publisher Id: TOPEJ-9-236
Article History:Received Date: 02/04/2016
Revision Received Date: 6/6/2016
Acceptance Date: 29/6/2016
Electronic publication date: 29/11/2016
Collection year: 2016
open-access license: This is an open access article licensed under the terms of the Creative Commons Attribution-Non-Commercial 4.0 International Public License (CC BY-NC 4.0) (https://creativecommons.org/licenses/by-nc/4.0/legalcode), which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.
Due to the high rate of proppant flowback after hydraulic fracturing stimulations, surface modified quartz sand proppants with excellent proppant flowback control abilities, self-aggregating proppants, were prepared. These surface modified proppants can aggregate together spontaneously and form a proppant column in water based liquid environment. Analyses show that the strong hydrogen bonds contribute to the absorption of the surface modifier onto the proppants, and the softening effect of the water to the polymer coating prompts the connection between the proppants. Scanning electron microscope pictures show that proppant particles are stacked together tightly. The stable structure contributes to the macroscopic stability of the proppant column. The maximum sand free flow rate of the model packed with modified proppants is 2.8 times larger than that of untreated proppants by average, indicating that the self-aggregating proppants exhibit excellent proppant flowback control abilities. In addition, fines control tests show that the modified proppants can also prevent the migration of the formation fines effectively, reducing the conductivity loss caused by particle migrations. By virtue of the reaggreating property and the encapsulation action of polymer coating to the crushed fragments, the fracture conductivities are increased by 3 times even at large closure stresses. The results provide a new alternative for proppant flowback control while do little damage to the permeability of the proppant pack.