It would only be warmer then the deep sea ocean temp (near freezing) if the oil was located closer to a significant section of magma. If I'm not mistaken, deep wells (and 17,000 thru the crust is deep) have to use specially treated pipe in the drill stem because of the high heat that is encountered.
E.g., see this on the Homestake Mine.
The temperature of the rock at the bottom of the mine (8,000 ft) is 135 degrees F.
Probably all depends on how close you are to a magma column. For example, Yellowstone can get quite hot just a few feet down. Anyone have a map showing exactly where this leak is located in the Gulf of Mexico ? All I see on the surface water temp map is a strange oblong extension of colder then normal water extending out from the mid coast of Texas.
