Abstract: The methods and apparatus of the present invention include an tubing disposed within an conduit to assure flow through the outer pipe. The tubing string is nearly neutrally buoyant or substantially buoyant and has a cleaning and monitoring tool attached to its end. In a preferred embodiment of the present invention, an apparatus for removing material from an conduit includes an tubing extending through the conduit and having a flowbore adapted to flow fluids within the tubing and a monitoring and cleaning tool attached to and receiving the fluids from the tubing. The tool preferably includes a plurality of nozzles, a sonic measuring device, and an expandable element.