Conventional oil and gas production
Wells on land and at sea that bring oil and gas to the surface.
Capture · Fossil and nuclear · No. 44
- Capture
- Output: Liquid and gaseous fuel
Most oil never leaves the ground: typical fields bring up only 22-40% of what they hold.
Chart: Illustration: Conventional oil and gas production
Where it comes from
A rig drills through an impermeable seal into porous rock. Natural pressure pushes out at most about 20% of the oil; injecting water or gas lifts that to 35-45%.
Onshore fields supply about 70% of world oil and offshore about 30%, from shallow-water platforms to floating production ships in water over 400 m deep.
Three things to know
- Oil sits not in underground lakes but in tiny pores of sandstone or limestone, gripped by capillary forces.
- Deep water gives only about 7% of oil and gas output, but about half of conventional discoveries in the past decade.
- Deepwater Horizon released 4.9 million barrels over 87 days in 2010, and 11 workers died in the blowout.
The journey
- 1 ReservoirOil and gas fill pores in rock
- 2 WellDrilled and lined with cemented steel
- 3 LiftNatural pressure, then pumps and injection
- 4 ProcessingOil, gas and water separated
- 5 ExportPipeline or tanker onward