In general you are correct but there are a couple other factors.
First you have to remove the debris from the pipe.
Next, you have to cut the pipe off to a fairly level position
Third, you have to contend with a non-round pipe.
Fourth, during the insert, you will have a smaller pipe attempting to deal with a large volume. This means you will need to have high velocity suction already going on the “relief pipe”.
Fifth, when the pipe is inserted, you will need to be able to exert many tons of pressure to force the pipe into the existing configuration.
Sixth, you will then need to form a seal. Most likely it will need to be a high pressure seal.
Lastly, you will need to weld the relief pipe in place.
So I’m thinking the relief pipe needs to be a very strong inner steel pipe able to withstand explosive pressure. Then put a series of rings of explosives around the steel pipe. These should be “pushing” explosives not bursting explosives (i.e. low velocity). Then put he whole assembly inside of a copper pipe. The idea being that if you push 20 to 40 feet of this configuration into the well, then pop the explosives, the copper will push against the inside of the well making a seal with the exiting pipe. Later, robotic welders can weld a collar to the new pipe and weld it to the existing pipe. This should provide a solid seal
Taxcontrol:
Great comments, in my earlier days I was a union Steamfitter Welder (yes I said union).
Another pressure reducing option (and the main obstacle is reducing the internal pressure at the work zone along with the voulme of the flow) would be to install a series of “hot tap” relief valves along the pipe. For those unfamilar with that technology, essentially placing a saddle assembly on the exterior of the pipe that has a valve bolted to it. You then drill through the valve in to the flowing pipe creating a diversion for the fluid (oil in this case) to be released and reducing the pressure and flow in the remaining end of the pipe. The relief valves can then be closed after dealing with the open end of the pipe.
As for “trueing up” the out of round pipe, I don’t see that as critical to the solution I offered up but for your scenario I could see it.