Explanation:

The extraction of petroleum is the process by which usable petroleum is drawn out from beneath the earth's surface location. The oil well is created by drilling a long hole into the earth with an oil rig. A steel pipe (casing) is placed in the hole, to provide structural integrity to the newly drilled well bore. Holes are then made in the base of the well to enable oil to pass into the bore. Finally, a collection of valves called a "Christmas tree" is fitted to the top; the valves regulate pressures and control flow. The drilling process comes under "upstream", one of the three main services in the oil industry, along with mid-stream and downstream. Hence option 2nd is correct.