2. Pay attention to the underlined stress in the following words.

4. You are going to learn some vocabulary to help you understand the text. Study the following dictionary entries, paying attention to specific term definition.

Well

1.An open space extending vertically through the floors of a building, as for stairs or ventilation.

2.An abundant source.

3.A mineral spring.

4.A container or reservoir for a liquid, such as ink.

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5.A deep hole or shaft sunk into the earth to obtain water, oil, gas, or brine.

Screen

1.The movie industry.

2.A body of troops or ships sent in advance of or surrounding a larger body to protect or warn of attack.

3.A movable device, especially a framed construction such as a room divider or a decorative panel, designed to divide, conceal, or protect.

4.A coarse sieve used for sifting out fine particles, as of sand, gravel, or coal.

Collar

1.A necklace.

2.An arrest, as of a criminal (slang).

3.The part of a garment that encircles the neck.

4.A restraining or identifying band of leather, metal, or plastic put around the neck of an animal.

5.Any of various ring-like devices used to limit, guide, or secure a machine part.

Hole

1.A fault or flaw.

2.An animal's hollowed-out habitation, such as a burrow.

3.An ugly, squalid, or depressing dwelling.

4.A hollowed place in something solid; a cavity or pit.

5.An opening or perforation.

Completion

1.A forward pass that is caught by a receiver.

2.The act of finishing or the state of being finished.

Washout

1.A total failure or disappointment.

2.One who fails to measure up to a standard, especially one who fails a course of training or study.

3.Erosion of a relatively soft surface, such as a roadbed, by a sudden gush of water, as from a downpour or floods.

5.Read the following texts and do the exercises.

Drilling

The well is created by drilling a hole 5 to 30 inches (13–76 cm) in diameter into the earth with an oil rig which rotates a drill bit. After the hole is drilled, a steel pipe (casing) slightly smaller than the hole is placed in the hole, and

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secured with cement. The casing provides structural integrity to the newly drilled wellbore in addition to isolating potentially dangerous high pressure zones from each other and from the surface. This process is all facilitated by a drilling rig which contains all necessary equipment to circulate the drilling fluid, hoist and turn the pipe, control downhole pressures, remove cuttings from the drilling fluid, and generate onsite power for these operations.

Completion

After drilling and casing the well, it must be 'completed'. Completion is the process in which the well is enabled to produce oil or gas. In a cased-hole completion, small holes called perforations are made in the portion of the casing which passed through the production zone, to provide a path for the oil to flow from the surrounding rock into the production tubing. In open hole completion, often 'sand screens' or a 'gravel pack' is installed in the last drilled, uncased reservoir section. These maintain structural integrity of the wellbore in the absence of casing, while still allowing flow from the reservoir into the wellbore. Screens also control the migration of formation sands into production tubulars and surface equipment, which can cause washouts and other problems, particularly from unconsolidated sand formations in offshore fields.

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After a flow path is made, acids and fracturing fluids are pumped into the well to fracture, clean, or prepare and stimulate the reservoir rock to produce hydrocarbons into the wellbore. Finally, the area above the reservoir section of the well is packed off inside the casing, and connected to the surface via a smaller diameter pipe called tubing. This arrangement provides a redundant barrier to leaks of hydrocarbons as well as allowing damaged sections to be replaced. Also, the smaller diameter of the tubing produces hydrocarbons at an increased velocity in order to overcome the hydrostatic effects of heavy fluids such as water.

In many wells, the natural pressure of the subsurface reservoir is high enough for the oil or gas to flow to the surface. However, this is not always the case, especially in depleted fields where the pressures have been lowered by other producing wells, or in low permeability oil reservoirs. Installing a smaller diameter tubing may be enough to help the production, but artificial lift methods may also be needed. Common solutions include downhole pumps, gas lift, or surface pump jacks. The use of artificial lift technology in a field is often termed as "secondary recovery" in the industry.