Hot tapping is a procedure that is used to drill a hole through a pressure barrier using special equipment to ensure that the pressure and fluids are safely contained while to gaining access to the interior of the barrier. In other words this is a method whereby a pipeline, tank or drill pipe can be safely drilled into while it is in service and under pressure.
Prior to starting the hot tap a clamp device is installed around the pipe to be tapped, this seals the pipe to the hot tap chamber, or in the case of a low pressure situation a flange or weld-o-let is welded on to the pipe, then a new valve is attached, then the hot tapping machine is mounted. The new hole is drilled then when the process is complete the drill is with drawn and the newly installed valve closed thereby containing the pressure and fluid. As long as there is room for the hot tapping equipment to be mounted hot tapping can be done from very small sizes( ½” and less) up to very large diameter( 36” and greater) and very high pressure situations.
Some examples where hot tapping is used are:
- To make a new connection into a pipeline without depressuring the line or shutting down.
- To drill through a damaged valve that will not open.
- To re-enter an abandoned well, where no valve exists.
- Where an obstruction or blockage in well bore tubulars exists when they are being tripped out of the hole this may result in abnormal pressures being trapped in the tube body as it comes to surface.
download of Acrobat Reader 
|
|
