Field Trials of the Annelida Robot, a Novel Self-Propelled Tool for Intervention in Obstructed Flexible Pipelines

Abstract This study aims the development of a novel tool for flow recovery on completely obstructed flexible pipelines. Resembling a combination of both PIGs and coiled tubing, widely spread in the oil and gas industry, this new self-propelled robot can move freely inside the pipeline. The robot architecture can overcome limitations of PIGs, such as the need for inside flow, and coiled tubing, such as moving upwards in negative angles. It enables finding and unclogging pipelines that have been out of production for several years, providing an extended lifespan for mature wells. The robot was entirely developed and can be divided in subsections such as: the hybrid umbilical cable, containing 2 hydraulic hoses, 2 copper wires and a bundle of 12 fiber optics wires; the embedded electronics, containing 1 single board computer, 8 DC/DC converters, 5 motor controllers and 1 actuation/sensing board; the electronic vessels, responsible for protecting the printed circuit boards up to 700 bar of external pressure; the hydraulic power unit - HPU, containing the reservoir, solenoids, manifolds, motors and pumps; the hydraulic power train - HPT, responsible for attaching the robot to the internal diameter of the pipeline and dragging itself forward and backwards; the intervention tool, responsible for heating and injecting fluids into the obstruction. Field tests were performed in an onshore environment, on a decommissioned and clean pipeline. Evaluations of the robot regarding velocity, distance, traction force, capacity for negative angle movement, and fail-safe operation were performed. The test was successful, with several hundred meters of displacement and up to 1 ton of traction force exerted by the robot. New trials are being planned with up to 3 tons of traction force.