6. Answer the questions:

1) What are the main natural reservoir drives?

2) When are secondary recovery techniques applied?

3) What are the main secondary recovery methods?

4) What is the purpose of thermally enhanced recovery techniques?

5) Why are surfactants injected into the reservoir?

6) When are tertiary recovery techniques applied?

7) What does the amount of recoverable oil depend on?

8) What is the task of petroleum engineers?

6. Fill in the gaps with the words from the list below:

waterflood (x2) enhanced diminish install natural

Injected submersible pumper drive

As the production of (1)________ gas and crude oil continues to (2)________ and water production increases, particularly in waterdriven reservoirs, the operator may begin (3)________, an (4)________ recovery method in which water is (5)________ into the reservoir at one well to (6) ________ hydrocarbons to other wells. However, with time oil production will continue to fall and water production will increase. As this occurs, the pumping time is increased until the lease (7)________ is producing the well twenty-four hours a day. 

At this time, the most practical way to improve production is to (8)_______ a system with greater production capability. One of the choices, especially in high-volume (9)_______ operations, is the electrically driven (10)________ pump. It is the pump that is lowered into the fluid to be pumped. 

7. Describe the process of a tertiary recovery technique presented in the picture. Describe all the stages and the effects of this process. Use Application 1 to help you present your description:

8. Work in pairs. Imagine you are planning the recovery from an oilfield. Prepare your speech and give details to support your ideas. Describe the natural drives of the reservoir and the recovery techniques that you will use, and predict the percentage of oil recovery at every stage. You have the rock properties and some recovery issues to deal with:

target recovery – 75%

primary recovery – 7%

gas oil ratio is low

the oil is very viscous

the oil-bearing rock is low-permeable

UNIT 5 ENVIRONMENTAL ISSUES

1. Study the terms:

Runoff, n – water or other liquid that runs off land into streams and rivers

Seepage, n – the process by which a liquid flows slowly and in small quantities through sth, or the result of this process

Contaminate, v – to pollute

Remediation, n – recultivation, restoration of soil

Permeate, v – to pass through or inside sth

Degrade, v – to change sth to a simpler chemical form

Ignite, v – to make sth burn

Cleanup, n – a process of cleaning

Booms, n – special floating defence made of bars and wood to prevent spilled oil from distributing further into the distance

Blowout, n – uncontrolled blowing of oil from the well

Generate, v – to produce

Impurities, n – a constituent which impairs the purity of something

Additives, n – a substance added to sth in small quantities to improve it

Emission, n – release of some substances

Release, v – to let out, discharge

Flare, v – to burn gas in flares

Near, v – to become close to sth