How is oil extracted?

Geologists and surveyors¹ search for places where crude oil could be trapped underground. After performing some specific measurements and taking samples,² they drill to confirm that there is actually oil. In the early days, successfully hitting an oil field might have meant being showered by a gusher³ of mud and oil, with the consequent loss of the initial outpouring⁴' and the risk of explosion. However, by means of measuring instruments and special valves,⁵ today's drilling rigs⁶ prevent this from happening. Smaller and deeper drillings are also possible today. Eventually, the pressure

that makes the oil and gas emerge decreases, and it must be maintained by the injection of water, chemicals, carbon dioxide, or other gases, such as nitrogen.⁷ Depending on the zone, oil can have different degrees of density. Naturally, light oil is by far preferred, for it is easier to obtain and refine.⁸

As explained by the American Petroleum Institute, modern technology includes horizontal drilling, done virtually parallel to the earth's crust, which reduces the number of wells that must be bored.⁹

Offshore¹⁰ extraction, which began in 1947 in the Gulf of Mexico, greatly increased oil production. Of course, the extraction method used has a direct effect on the price of the final product.*

¹ surveyor - геодезист

² sample - проба, образец

³ gusher - нефтяной фонтан

⁴ outpouring - излияние

⁵ valve – клапан

⁶ rig - буровая установка

⁷ nitrogen – азот

⁸ refine – очищать

⁹ bore - бурить

¹⁰ offshore - находящийся на некотором расстоянии от берега (в море)

Answer the following questions:

1. How was oil extracted in the early days?

2. And how is oil extracted now?

3. What kind of oil is easier to obtain and refine?

4. Can you tell about some modern technologies of drilling oil wells?