How do conventional oil resources differ from unconventional oil resources in terms of extraction methods?

• A. Conventional oil is recovered only by in-situ combustion.
• B. Conventional oil is liquid hydrocarbons recoverable with standard methods; unconventional includes shale oil, oil sands, tight oils requiring enhanced recovery or processing.
• C. Conventional oil is always more expensive to produce than unconventional.
• D. Conventional oil is gas, not liquid.

Answer: (B)

Extraction methods differentiate conventional oil resources from unconventional ones. Conventional oil consists of liquid hydrocarbons that can be recoverable with standard drilling and production practices, often starting with primary recovery driven by reservoir pressure and followed by secondary methods like water flooding. Unconventional resources—such as shale oil, tight oils, and oil sands—don’t flow readily and require more intensive techniques or processing. Shale and tight oil typically need hydraulic fracturing and horizontal drilling to create pathways for oil to move to the well, turning otherwise low-permeability rock into productive reservoirs. Oil sands usually require surface mining or in-situ methods (for example, steam-assisted techniques) to separate and upgrade the bitumen into usable crude. So the key distinction lies in the extraction approach: conventional uses standard methods, while unconventional requires enhanced recovery techniques or substantial processing. The other options are not accurate because in-situ combustion isn’t a standard method for conventional oil, costs vary and aren’t a defining feature, and conventional oil is not gaseous but liquid.