New Technologies and Innovations used for well drilling

New technologies have also helped reduce the environmental impact of energy production by allowing more oil and gas to be produced with fewer wells. Well completion is the final step of the drilling process, where the connection to hydrocarbon-bearing rock is established. Advancements in drilling technology have also enabled the recent growth in production from shale and other unconventional oil and gas reservoirs in many parts of the world, using a combination of hydraulic fracturing and horizontal, extended reach drilling.

1. Horizontal Drilling

Horizontal drilling is a directional drilling process aimed to target an oil or gas reservoir intersecting it at the entry point with a near-horizontal inclination, and remaining within the reservoir until the desired bottom hole location is reached. Horizontal drilling provides more contact to a reservoir formation than a vertical well and allows more hydrocarbons to be produced from a given wellbore.

There are many kinds of the reservoir where the potential benefits of horizontal drilling are evident:

• in conventional reservoirs

Thin reservoirs; Reservoirs with natural vertical fractures; Reservoirs where water (and gas) coning will develop; thin layered reservoirs; heterogeneous reservoirs;

• in unconventional reservoirs

shale gas/oil, tight gas/oil, CBM, heavy oil, oil sands, etc

2. Multilateral Drilling

Sometimes oil and natural gas reserves are located in separate layers underground and multilateral drilling allows producers to branch out from the main well to tap reserves at different depths. A multilateral well is a single well with one or more wellbore branches radiating from the main borehole.

General multilateral configurations include:

Multi-branched wells, forked wells, wells with several laterals branching from one horizontal main wellbore, wells with several laterals branching from one vertical main wellbore, wells with stacked laterals, and wells with dual-opposing laterals.

Multilateral Well Configurations

• Multilateral wells configuration enhances productivity.
• In shallow or depleted reservoirs, branched horizontal wellbores are often most efficient, whereas, in layered reservoirs, vertically stacked drain-holes are usually best.
• In fractured reservoirs, dual-opposing laterals may provide maximum reservoir exposure, particularly when fracture orientation is known.

3. Extended Reach Drilling

Extended Reach Drilling allows producers to reach deposits that are great distances away from the drilling rig and this helps producers tap oil and natural gas deposits undersurface areas where a vertical well cannot be drilled, such as underdeveloped or environmentally sensitive areas.
The current world record (around 2013) for the longest measured depth ERD well is the Chayvo Z-42 well (Exxon Neftegas Limited, Sakhalin Island, Russia) with a measured depth of 41,667 ft. and a horizontal departure of 38,514 ft.

The objective of the hole- cleaning program in ERW is to improve drilling performance by avoiding stuck pipe, avoiding tight hole on connections and trips, maximizing the footage drilled between wiper trips, eliminating back reaming trips prior to reaching the casing point and maximizing daily drilling progress.

4. Automated drilling

• Automated drilling is one of the oil industry’s most important innovation targets.
• The sources now being tapped, such as shale gas and coal-bed methane, require a very large number of wells, and automating the drilling process would be an obvious way to keep the costs under control, and also gets around a problem which many sectors of engineering are experiencing
• Automated drilling would be faster, more efficient, and safer, as it reduces the number of workers on site.

This technique would have a number of advantages:

• First, it reduces the amount of energy needed to drill the bore; wider bores need more energy because they have to displace more material, so for a given depth of bore, less rock has to be removed.

• It also uses less steel, less cement grouting, and less drilling mud; as well as a smaller drilling rig.

• It also allows for greater depths to be achieved.

Credits: Oil and gas portal