Question

1. the odor - causing component of natural gas we use is

a carbon dioxide (co₂)
b mercaptan (ch₃sh)
c methane (ch₄)
d propane (c₃h₈)

1. when exploring for oil or natural gas deposits, we may use

i hydraulic fracturing
ii seismic data
iii core sampling
iv test wells
a only ii and/or iii
b only i, ii and/or iv
c only ii, iii and/or iv
d all of the options

1. which part of the oil and natural gas process involves recovering and bringing fluids to the surface?

a exploration
b transportation
c production
d refining

1. to enhance the recovery of oil and natural gas from wells, a process known as hydraulic fracturing is sometimes used. \fracturing\ can be described by which of the following?

i occurs less than 1,000 feet below the surface.
ii fluids are injected at high pressure, producing fissures that allow hydrocarbons to flow.
iii hydraulic fracturing fluids contain water and other materials.
iv hydraulic fracturing increases access to oil and natural gas found in tight pores.
a only ii, iii and iv
b only ii and iii
c all of the options
d only i, ii and iv

Explanation:

• Question 17: Natural gas is odorless. Mercaptan (\(CH_3SH\)) is added to it to give it an odor so that gas leaks can be detected. Carbon dioxide (\(CO_2\)) is a greenhouse gas, methane (\(CH_4\)) is the main component of natural gas (odorless), and propane (\(C_3H_8\)) is a different hydrocarbon fuel.
• Question 18: Seismic data (II) helps in mapping subsurface structures, core sampling (III) gives information about rock and fluid properties in the subsurface, and test wells (IV) are drilled to confirm the presence of oil or gas. Hydraulic fracturing (I) is mainly a production - enhancement technique, not an exploration method.
• Question 19: Production is the stage where fluids (oil and gas) are recovered and brought to the surface. Exploration is about finding the deposits, transportation is about moving the produced fluids, and refining is about processing the crude oil.
• Question 20: Hydraulic fracturing occurs at depths much greater than 1000 feet. Fluids (containing water and other materials - III) are injected at high pressure (II) to create fissures. This increases access to oil and gas in tight pores (IV).

Answer:

1. B. mercaptan (\(CH_3SH\))
2. C. only II, III and/or IV
3. C. production
4. A. only II, III and IV