What is a Horizontal Well?
A horizontal well is a groundbreaking directional drilling technique where an oil or gas wellbore is drilled at an angle of at least eighty degrees to a vertical wellbore. This innovative method has grown increasingly common and productive due to its efficiency in accessing oil and natural gas in challenging or abnormal reservoir formations.
Key Takeaways
- Efficient Access: Operators implement horizontal wells to effectively retrieve oil and natural gas from hard-to-reach reservoirs.
- Enhanced Reach: This technique allows access to subsurface resources not directly beneath surface drilling points.
- Economic Advantage: Lower extraction costs and improved efficiency mark key benefits.
How a Horizontal Well Works
The prominence of horizontal wells soared during the 2010s, powered by technological advancements making oil and natural gas extraction notably cost-effective and efficient. The methods involve two critical components:
- Mud Motor: This pump mechanism, powered by drilling fluid (mud), enables directional boring into the earth, adapting configurations for non-vertical drilling directions.
- Measurement While Drilling (MWD): Essential for real-time subsurface analysis, this tool guides and targets horizontal drilling.
Additionally, modern drilling techniques include drill bits capable of bending through hydraulic jetting, facilitating precise directional adjustments. With computer-aided technologies and GPS, operators can accurately control the drill bit’s angle and trajectory relative to the resource field.
Horizontal Drilling vs. Vertical Drilling
Horizontal drilling has emerged as a prominently favorable technique when compared to traditional vertical drilling, presenting key advantages:
- Expanded Access: Unlocks access to widespan underground areas from a single drilling pad.
- Well Control: Capable of relieving pressure or sealing out-of-control wells through adjacent relief wells.
- Utility Applications: Useful for constructing underground pipelines or utility lines beneath obstacles like rivers or buildings.
Horizontal Drilling and Hydraulic Fracturing
Horizontal wells play a crucial role in enhancing the hydraulic fracturing (fracking) process, pivotal for accessing enormous U.S. shale gas and oil reserves. Conventional drilling methods struggle with impermeable shale formations, but horizontal drilling coupled with high-pressure injections that fracture the rock facilitates flow of trapped natural gas and petroleum. This technique transforms unreachable deposits into viable resources through strategic horizontal penetration and forced fracturing solutions.
Related Terms: Directional Drilling, Mud Motor, Measurement While Drilling, Vertical Drilling, Hydraulic Fracturing.
References
- U.S. Energy Information Administration. “Horizontally Drilled Wells Dominate U.S. Tight Formation Production”.
- International Association of Drilling Contractors. “New Directional Drilling System Combines Improved Mud Motor, MWD Technologies”.
- Drillers. “Directional Drilling: Everything You Ever Wanted to Know”.
- University of Calgary, Energy Education. “Horizontal Well”.
- U.S. Energy Information Administration. “Hydraulically Fractured Horizontal Wells Account for Most New Oil and Natural Gas Wells”.
