Involves the use of specially designed remotely-controlled equipment operated from surface and used in conjunction with or built-in CCTV viewing facilities.
In many instances the operation is two-fold.
First a robot is used to clean and prepare the area of the defect to ensure that any repair materials have a good key to adhere to. This may involves using a grinder head or cutting tool to remove intrusions or shape the defect to ensure that repair materials can be fully effective.
Once prepared either the robot equipment is changed or a second robot is used to inject the repair the material into the defect, again using CCTV viewing to ensure the correct and effective repair is made.
To limit or eliminate any intrusion into the pipeline from the repair material robots may utilise smoothing paddles to level the repair site.