Drilling, Completing, and Producing from Oil and Natural Gas Wells

Fast Facts About
Drilling, Completing, and Producing From Oil and Natural Gas Wells

Once a suitable well location has been identified, permitted, and leased, the next steps for oil and natural gas development are drilling, completion, and production:

1. Drilling typically takes about 50-60 days. It starts with preparing the site (clearing and leveling) and setting up a drilling rig to drill a borehole and feed steel pipe into the well. Drilling mud is used to manage downhole pressures, provide information about the rock layers being drilled through, and keep the drill bit cool. Safety equipment, such as a blowout preventer, is installed to prevent oil and natural gas from being released in rare unexpected overpressure situations.
2. Completion is a 1-5 week process where the steel pipe in the well is perforated to connect the well bore to the oil or gas reservoir. As needed, additional recovery techniques such as hydraulic fracturing (for low permeability reservoirs) or steam flooding (for thick oil) are applied. A Christmas Tree (series of valves) is installed at the top of the well. As reservoir pressure declines, a pumpjack is installed.
3. Production from a completed well can last 50+ years. During the production step, the well is monitored, maintained, and managed. In the U.S. the mineral rights owners (individuals) typically receive royalty interest payments on the oil and natural gas produced. In most other countries, the federal government owns the mineral rights.

See our Prospecting for Oil and Natural Gas page for information on exploration, permitting, and leasing. See our Oil and Natural Gas pages for information on processing, refining, and transporting oil and natural gas after they are produced.

Drilling

Vertical Drilling

• Exposes only the vertical dimension of the reservoir
• Requires many wells per square mile to extract the oil or natural gas

Directional Drilling

• Increases the length of pipe exposed to the reservoir by drilling at an angle
• Enables drilling where vertical access is difficult, such as offshore, under an urban area, under a lake, or under a difficult-to-drill formation
• Allows grouped wellheads on one surface location

Horizontal Drilling

• An extension of the directional drilling technique applied to unconventional reservoirs
• Each horizontal borehole does the work of several vertical wells with even more exposure of pipe to the reservoir
• The radius of the turn from vertical to horizontal is ~1/4 mile

Number of Drilling Rigs by Region

(May 2023)

Completion

Horizontal drilling and hydraulic fracturing are only done at scale in the US.

Production

Types of Oil Recovery*

*_{Natural gas is only recovered through natural flow or associated with oil}

Conventional vs Unconventional*

*_{Conventional - naturally high permeability; unconventional - low permeability}

US

_{*Production per well is much lower in the US than in other countries due to subsidies for stripper wells that produce very little oil. Those subsidies are intended to encourage domestic oil production. The US is also the only country in the world that has private mineral rights.}

Onshore vs Offshore

Climate Impact: High

• Methane leakage from drilling sites

Environmental Impact: High

• Disturbances to land and marine ecosystems
• Irresponsible oil production can lead to seismicity
• Potential for oil and gas to leak into groundwater if wells not properly maintained
• Oil spills
• Site disturbance

Our Lecture on
Drilling, Completing, and Producing from Oil and Natural Gas Wells

This is our Stanford University Understand Energy course lecture on drilling, completing, and producing from oil and natural gas wells. We strongly encourage you to watch the full lecture to understand this complex topic within the context of the oil and natural gas energy systems. For a complete learning experience, we also encourage you to watch / read the Essential videos and readings we assign to our students before watching the lecture.

Presented by: Jane Woodward, Adjunct Professor, Civil and Environmental Engineering, Stanford University; Founder and Managing Partner, WovenEarth Ventures; Founding Partner, MAP Energy
Recorded on: October 4, 2023   Duration: 76 minutes

Next Topic: Oil Other Energy Topics to Explore