Unit 5. Advanced drilling techniques

5.1. Learn the new words and expressions

1. advances – достижения	6. to branch out – разветвляться, расширяться
2. to generate – вызывать; производить	7. to tap – вскрывать
3. sensitive ecosystem – неустойчивая экосистема	8. dramatically – значительно
4. horizontal drilling – горизонтальное бурение	9. extended reach drilling – наклонно-направленное бурение (с увеличенным отклонением от оси скважины)
5. multilateral – многоствольная скважина	10. twists – повороты; изгибы

5.2. Study the terms

Reservoir rock – a permeable rock that may contain oil or gas in appreciable quantity and through which petroleum may migrate.

Extended-reach well – a directionally drilled well that has a high degree of deflection.

Layer – a bed, or stratum, of rock.

Accumulate – to amass or collect. When oil and gas migrate into porous formations, the quantity collected is called an accumulation.

Depth – the distance to which a well is drilled, stipulated in a drilling contract as contract depth. Total depth is the depth after drilling is finished. On offshore drilling rigs, the distance from the baseline of a rig or a ship to the uppermost continuous deck.

Hole – in drilling operations, the wellbore or borehole.

Wellbore – the hole drilled with the bit. A wellbore may have casing in it or it may be open (uncased); or part of it may be cased, and part of it may be open.

Contractor (drilling contractor) – an individual or group of individuals who own a drilling rig and contract their services for drilling wells to a certain depth.

Pipeline – a system of connected lengths of pipe, usually buried in the earth or laid in the seafloor, that is used for transporting petroleum, petroleum products, chemicals, and natural gas. A pipeline serves as both a conveyor and a temporary container.

Tap – to extract or cause to flow by means of a borehole, e.g., to tap a reservoir.

Location – the place where a well is drilled.

Offshore platform – an immobile offshore structure from which wells are produced.

5.3. Read and translate the text advanced drilling techniques

Oil and natural gas wells have traditionally been drilled vertically, at depths ranging from a few thousand feet to as deep as five miles. Today, advances in drilling technology allow oil and natural gas companies to reach more reserves while reducing environmental impact by:

- reducing the surface “footprint” of drilling operations,

- drilling smaller holes and generating less waste

- creating less noise,

- avoiding sensitive ecosystems, and

- completing operations more quickly.

Here are some technologies used:

Horizontal Drilling - Horizontal drilling starts with a vertical well that turns horizontal within the reservoir rock in order to expose more open hole to the oil. These horizontal “legs” can be over a mile long; the longer the exposure length, the more oil and natural gas is drained and the faster it can flow. More oil and natural gas can be produced with fewer wells and less surface disturbance. However, the technology only can be employed in certain locations.

This method was   developed and first used in 1971   in the USA by the corporation "Titan Contractors", California. There was a pipeline with a diameter 115.3 mm and length 231.6 m laid there. Since then the Horizontal Drilling gained great popularity abroad. Already 30 years nobody breaks the pavement, dismantle the railroad, change traffic arteries and create other inconveniences for people for pipelining.

Multilateral Drilling - Sometimes oil and natural gas reserves are located in separate layers underground. Multilateral drilling allows producers to branch out from the main well to tap reserves at different depths. This dramatically increases production from a single well and reduces the number of wells drilled on the surface.

Extended Reach Drilling - Extended reach drills allow producers to reach deposits that are great distances away from the drilling rig. This can help producers tap oil and natural gas deposits under surface areas where a vertical well cannot be drilled, such as under developed or environmentally sensitive areas. Wells can now reach out over 5 miles from the surface location. Offshore, the use of extended reach drilling allows producers to reach accumulations far from offshore platforms, minimizing the number of platforms needed to produce all the oil and gas. Onshore, dozens of wells can be drilled from a single location, reducing surface impacts.

Complex Path Drilling - Complex well paths can have multiple twists and turns to try to hit multiple accumulations from a single well location. Using this technology can be more cost effective and produce less waste and surface impacts than drilling multiple wells.