Clean head, system and method for use in cleaning a fluid conduit

A cleaning system for use in cleaning a fluid conduit for transporting hydrocarbons and/or a fluid conduit in a hydrocarbon wellbore, the cleaning system comprising:

• a cleaning head for a cleaning system for use in cleaning a fluid conduit for transporting hydrocarbons and/or a fluid conduit in a hydrocarbon wellbore, the cleaning head comprising:
• a body defining an outer surface having a cross-section which is configured to match, or be comparable to, a cross-section of an inner surface of the fluid conduit, wherein the body defines a jetting fluid input port on an input side of the body for connection to tubing, a jetting fluid output port on an output side of the body, and a jetting fluid flow path extending from the jetting fluid input port to the jetting fluid output port, and wherein the body defines a bypass fluid input port on the input side of the body, a bypass fluid output port on the output side of the body, and a bypass fluid flow path extending from the bypass fluid input port to the bypass fluid output port, the bypass fluid flow path being separate from the jetting fluid flow path,
• wherein the jetting fluid flow path is located radially inwardly of the bypass fluid flow path;
• a jetting head defining one or more jetting apertures, wherein the jetting head is coupled to the jetting fluid output port so that the one or more jetting apertures are in fluid flow communication with the jetting fluid flow path;
• and
• a variable aperture valve in the bypass fluid flow path, the variable aperture valve defining a variable aperture which varies in response to a variation in fluid flow rate through the bypass fluid flow path;
• a jetting fluid pump;
• a length of tubing defining a tubing fluid flow path, wherein one end of the tubing is connected to the jetting fluid input port of the cleaning head such that the tubing fluid flow path is in fluid flow communication with the jetting fluid flow path and the other end of the tubing is connected to the jetting fluid pump;
• a tubing injector apparatus for injecting the tubing into, and/or retracting the tubing from, the fluid conduit;
• and
• a pressure control arrangement for containing pressure within the fluid conduit, wherein the pressure control arrangement is configured to provide a seal with an outer surface of the tubing whilst permitting the tubing to be injected into, and/or retracted from, the fluid conduit.