Abstract: Embodiments of the present invention generally relate to a method of treating a tubular string using a pigtrain. In one embodiment, a method of treating a tubular string includes injecting working fluid between a lead pig and a trail pig of a pigtrain. A bypass pig of the pigtrain is in a first position between the lead pig and trail pig and closer to the lead pig. The method further includes injecting propellant behind the trail pig, thereby driving the pigtrain through the tubular string. The bypass pig gradually moves from the first position to a second position closer to the trail pig, thereby agitating the working fluid.

Abstract: Embodiments of the present invention generally relate to a method of treating a tubular string using a pigtrain. In one embodiment, a method of treating a tubular string includes injecting working fluid between a lead pig and a trail pig of a pigtrain. A bypass pig of the pigtrain is in a first position between the lead pig and trail pig and closer to the lead pig. The method further includes injecting propellant behind the trail pig, thereby driving the pigtrain through the tubular string. The bypass pig gradually moves from the first position to a second position closer to the trail pig, thereby agitating the working fluid.

Abstract: Embodiments of the present invention generally relate to a method of drying a tubular string to prevent bedwrap corrosion. In one embodiment, a method of drying a tubular string includes deploying a first bypass pig in the tubular string. The method further includes injecting propellant behind the first bypass pig, thereby driving the first bypass pig through the tubular string. A portion of the propellant bypasses the first bypass pig, thereby drying an inner surface of the tubular string.

Abstract: Embodiments of the present invention generally relate to a bypass pig. In one embodiment, a pig for cleaning a tubular string includes a cylindrical body and two or more scrapers disposed along an outer surface of the body. The scrapers are operable to engage and clean an inner surface of the tubular string. The pig further includes a bypass formed between the scrapers. The bypass is operable to: intake a portion of propellant from a tail of the body, conduct the portion of propellant along an outer surface of the body, and discharge the portion of propellant in front of the body.