Improved Oil Recovery

Современные методы нефтедобычи

oil recovery добыча нефти, нефтеотдача

displace перемещать

thermal recovery тепловая добыча

dissolve растворяться

detergent вспенивающий агент

surfactant сурфактант

hamper тормозить, затруднять

unpredictability непредсказуемость

fertilizer удобрение

reservoir месторождение, нефтеносный слой

drive вытеснение

bubble out пузыриться, булькать

gas cap газовая шапка, газовый купол

slug водяная пробка

miscible пособный смешиваться

Task 1. Read and translate the text. Answer the questions:

Задание 1. Прочитайте и переведите текст. Ответьте на вопросы к нему:

Primary, secondary and tertiary recovery

So, what exactly is the purpose of enhanced recovery? Well, as I'm sure you know, crude oil development and production in US oil reservoirs can include up to three distinct phases: primary, secondary and tertiary (or enhanced) recovery. During primary recovery, the natural pressure of the reservoir or gravity drives oil into the wellbore, combining with artificial lift techniques (such as pumps) to bring the oil to the surface. But only about 10% of a reservoir's original oil in place is typically produced during primary recovery. Secondary recovery techniques add to the field's productive life by injecting water to displace the oil and drive it to a production wellbore, resulting in the recovery of another 20 to 40% of the original oil in place. However, a lot of the easy- to-produce oil has already been recovered from US oilfields, and so producers are increasingly using tertiary or enhanced oil recovery (also called EOR) techniques that offer us prospects for ultimately producing 30 to 60% or more of a reservoir's original oil in place.

1. What is the difference between primary, secondary and tertiary recovery?

2. Why are US producers using tertiary recovery now?

Task 3. Read the extract and discuss how each method works:

Задание 3. Прочитайте текст и обсудите, как работают разные методы добычи:

Enhanced recovery methods

Three major categories of EOR have been found to be commercially successful in varying degrees. First of all, there's thermal recovery, which involves the introduction of heat, such as the injection of steam to lower the viscosity or thin the heavy viscous oil, and improve its ability to flow through the reservoir. Thermal techniques account for over 50% of US EOR production, primarily in California.

Then there's gas injection, which uses gases such as natural gas, nitrogen or carbon dioxide that expand in a reservoir to push additional oil to a production wellbore, or other gases that dissolve in the oil to lower its viscosity and improve its flow rate. Gas injection accounts for nearly 50% of EOR production in the United States.

And thirdly, there's chemical injection, which can involve the use of long-chained molecules called polymers.

These increase the effectiveness of waterfloods, or the use of detergent-like surfactants, to help lower the surface tension that often prevents oil droplets from moving through a reservoir. Chemical techniques account for less than 1 % of US EOR production. However, these techniques have been hampered by their relatively high cost and, in some cases, by the unpredictability of their effectiveness.

Task 4. Read the extract and make notes on each of the projects:

Задание 3. Прочитайте текст и обсудите, как работают разные методы добычи: