What I was saying is water isn't the only pressure, but the earth itself is squeezing the oil out of a "little" hole, so that would be a lot of pressure coming out. It has to be a lot just to push against the water.
If the robots saw off the bent and twisted leaking pipe, it will release even more oil. However, the may be able to weld a flange around the pipe, and then place a valve over it, and bolt it down, then turn it off. It could, however, break the bolts and break off the valve if it is under that much pressure. Don't know how good the robots can weld that deep, underwater, and freezing cold.