Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)This paper describes a systematic investigation to verify the potential of wormlike micelles (WLMs) as additives to improve gravel-pack operations. This is an important step of the completion operations, in which a sand core along of an oil well is created. WLMs have high potential to reduce the hydrodynamic drag of sand suspensions during the gravel-pack operation. The capability of WLMs to survive in aqueous solution with high salt content and at the temperature of the reservoir was investigated. The screening of the best formulation was carried out in a rheometer under turbulent conditions. Based on the rheological results the best formulations were used to investigate the levels of hydrodynamic drag reduction (HDR) in circuits. The more appropriated WLMs were formed by the combination of commercial surfactants Ethoquad O/12 with Arquad 12-50 and sodium salicylate (NaSal). We also checked the effect of the presence of WLMs on the transportation of sand grains in conditions close to the ones used in gravel pack operations. (C) 2016 Elsevier B.V. All rights reserved.146142148Brazilian agency FAPESP [2005/00873-8]Brazilian agency CNPq [301016/2015-1]PETROBRASFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)