The present invention provides systems and methods for curing a leakage in a pipeline, the system including at least one gel pig and at least one sealant composition; wherein the at least one gel pig and the at least one sealant composition form a pig train, adapted to move along the pipeline to a region of the leakage and to seal the leakage.

A gripper assembly for a pipeline plug includes an actuator plate, bowl, and gripper unit. The actuator plate includes a wedge surface. The bowl includes a bowl expansion face. The bowl expansion face has bowl stairsteps. The gripper unit includes a gripper body. The gripper body is positioned between the actuator plate and the bowl. The gripper body includes an expansion face having gripper stairsteps, the gripper stairsteps corresponding to the bowl stairsteps.

An apparatus includes a hub and multiple thin, flat, deformable panels. Each panel is a trapezoid with parallel base and top. The panels are foldably connected together base-to-top to form a closed ring. A proximal end portion side of each panel is attached the hub. A proximal portion of each panel is wound around the hub; a distal portion of each panel extends tangentially away from the hub. Proximal portions of each panel winding around the hub decreases an apparatus outer diameter; proximal portions of each panel unwinding from around the hub increases the apparatus outer diameter.

A pipeline plug includes a pressure head; a seal assembly; a seal expansion ring; a plurality of gripper bodies, a sliding gripper, and an actuator. Each gripper body is coupled to the seal expansion ring. Radial expansion of the gripper bodies supports radial expansion of the seal expansion ring. Additionally, radial expansion of the seal expansion ring supports radial expansion of the gripper bodies. The sliding gripper is slidingly coupled to a radially outer surface of the gripper body.

A mechanical plug includes first and second plug portions and an elongate member. The first plug portion includes a first endwall and a first sidewall. The first sidewall includes a female section extending in a direction along a longitudinal axis of the mechanical plug. The second plug portion is movable relative to the first plug portion. The second plug portion includes a second sidewall, a second endwall coupled to the second sidewall, and a seal. The second sidewall includes a male section extending in a direction along the longitudinal axis. The seal surrounds a portion of the male section in a region along the longitudinal axis between the second endwall and the female section. The elongate member is coupled to the first and second plug portions. Actuation of the elongate member moves the first plug portion and the second plug portion toward each other to compress the seal.

A mechanical plug includes first and second plug portions and an elongate member. The first plug portion includes a first endwall and a first sidewall. The first sidewall includes a female section extending in a direction along a longitudinal axis of the mechanical plug. The second plug portion is movable relative to the first plug portion. The second plug portion includes a second sidewall, a second endwall coupled to the second sidewall, and a seal. The second sidewall includes a male section extending in a direction along the longitudinal axis. The seal surrounds a portion of the male section in a region along the longitudinal axis between the second endwall and the female section. The elongate member is coupled to the first and second plug portions. Actuation of the elongate member moves the first plug portion and the second plug portion toward each other to compress the seal.

A seal assembly for a pipeline plug may include a pressure head including a forcing face. The seal assembly may include a primary tapered ring including an expansion face. The expansion face may abut the forcing face. The seal assembly may include primary seal ring. The seal assembly may include a squeezer assembly, the squeezer assembly including at least one seal face, the seal face abutting the primary seal ring. The seal assembly may include a secondary tapered ring, the secondary tapered ring including a wedge squeezer face, the wedge squeezer face abutting a wedge face of the squeezer assembly. The seal assembly may include a bowl, the bowl including a wedge face, the wedge face in abutment with an expansion face of the secondary tapered ring.

The present invention provides methods and methods for curing a leakage in a pipeline, the method including at least one gel pig and at least one sealant composition; wherein the at least one gel pig and the at least one sealant composition form a pig train, adapted to move along the pipeline to a region of the leakage and to seal the leakage.

The present invention provides methods and methods for curing a leakage in a pipeline, the method including at least one gel pig and at least one sealant composition; wherein the at least one gel pig and the at least one sealant composition form a pig train, adapted to move along the pipeline to a region of the leakage and to seal the leakage.

Method for replacing a chemical injection valve connected to a well head via an injection line housing, where an end of an injection line is provided within the injection line housing, includes: connecting an injection line plugging tool to the chemical injection valve; providing threads in the end of the injection line by means of the injection line plugging tool; connecting an injection line plug to the threads of the injection line by the injection line plugging tool; disconnecting the chemical injection valve from the injection line housing; connecting a further chemical injection valve to the injection line housing; connecting the injection line plugging tool to the further chemical injection valve; removing the injection line plug from the end of the injection line by the injection line plugging tool; disconnecting the injection line plugging tool from the further chemical injection valve.