A horizontal well is a multi-directional drilling method that drills at least 80 degrees inclination to improve reservoir performance. In instances when vertical wells are not practical or the shape reservoir is difficult to reach, the horizontal approach is employed as an alternative method for drilling oil and gas.
Drilling at non-vertical angles may typically stimulate oil and gas reservoirs in ways that a vertical well cannot. Horizontal wells can be utilized to drill natural gas in previously unproductive zones when used in conjunction with hydraulic fracturing.
How Horizontal Drilling Works
A vertical well is usually drilled before a horizontal well is drilled. The pipe is hauled out of the well after drilling down to the target rock, and the drill bit is fitted with a motor. The drilling mud’s flow down the drill pipe powers the motor, which spins the bit without spinning the pipe. This allows the drill bit to travel in a direction that isn’t parallel to the drill pipe’s orientation.
The pipe and bit are lowered into the well in a horizontal well, and the bit drills a path that arcs from vertical to horizontal. Drilling resumes in a totally horizontal path after the necessary angle is obtained.
Although beneficial, hdd projects might cost up to three times as much as vertical drilling. However, the additional expense is usually offset by higher well output, which greatly increases the yield of gas and oil from a well.
Why Horizontal Wells are Used
Horizontal wells are chosen over vertical wells because of their efficiency in increasing oil field production. Horizontal drilling can cost up to three times more per foot than vertical drilling when paired with hydraulic fracturing.
Apart from efficiency in oil field production, there are various reasons why horizontal wells are used while drilling for oil and natural gas, as listed below:
Reach difficult targets.
Several of the reservoirs lie beneath a neighborhood, a park, or a congested city, making drilling difficult or impossible. To get underneath the unreachable locations, a vertical well is bored first, then curved to a horizontal angle. Horizontal drilling makes it possible to reach the target areas without disrupting a park or a residential area in this way.
Install a utility service where excavation is costly or impractical.
Utility companies may be required to drill horizontal wells in locations where excavation is unfeasible or too expensive when providing utility services such as electric lines or gas lines. When electric lines must cross a busy highway, for example, the power company may choose to construct a horizontal well beneath the roadway to pass the electric lines to the other side.
Drill a large region with less carbon footprint.
Horizontal wells can also be used to drill a large region with a single drilling pad, reducing the size of the oil and gas exploration footprint. When excavating oil on 1,000 acres of land, for example, an oil company can drill a single main well and branch off to the target oil fields numerous times. Many hdd projects minimize the land footprint of oil and gas exploration dramatically.
Boost well production in a fractured reservoir.
Pore spaces constructed in the form of cracks can be seen in some reservoirs. To allow free gas flow into the well, the exploration procedure must penetrate the cracks.
Horizontal wells achieve free flow by drilling into the earth in a direction where the highest amount of fractures are intersected. It necessitates drilling at the proper angles to the prevailing fracture path.
Relieve or seal the pressure in an “out-of-control” well.
A “relief well” can be drilled to intersect an out-of-control well. The intersecting well can be used to either relieve pressure in the overflowing well or close the original well.
Nowadays, with the advancement of horizontal and directional drilling equipment, engineers and contractors have a whole slew of new options when it comes to deciding where they want their wells drilled. They can drill them at any angle from one location across vast distances or deep into reserves that were once inaccessible due to expensive transportation costs.
This has opened up many opportunities for builders who now are able to tap in deeper resources on tighter budgets because there is no need for costly transportations anymore!