Process fluids influence on well productivity. Application of special-purpose fluids allows eliminate the negative effect of the well killing fluids; these fluids don’t make through a formation during operations of wells completion and workover and could be easily removed after the operations have been finished. In standard workover operations well killing fluids without tunable properties are usually used. Such method doesn’t protect a formation from liquid penetration, and often it is getting rather difficult to reach the process stabilization of the well.
Viscoelastic gels (VEG) act as a ‘flexible packer’ and are designed for temporary protection of productive formation on the stages of wells completion and development, during workover and insulation operations. Over 350 well killing operations using VEG have been carried out in the territory of Perm region within 2012-2013. Application of this technique provides specified effect concerning decrease of well- killing liquid volume and saving time needed for the process stabilization. However the well pumping equipment failures have been registered due to fouling with VEG residues. Noted problems could be eliminated by applying the proposed well- killing technique by using the composition with specified destruction time.
This study presents the results of laboratory research on VEG development with controllable service life. Introduction of this technique will allow reducing the likelihood of equipment failures and accelerating the process of reaching design basis conditions of the wells.
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