Question

d) pourquoi est-il plus complexe de produire du pétrole à partir des sables bitumineux que du pétrole liquide?

Explanation:

To produce oil from oil sands (sables bitumineux), several additional steps are needed compared to liquid oil production:

1. Extraction Complexity: Oil sands contain bitumen (a heavy, viscous hydrocarbon) mixed with sand, clay, and water. Extracting bitumen from the sand - clay - water mixture requires methods like surface mining (for shallow deposits) or in - situ techniques (like steam - assisted gravity drainage for deep deposits). In contrast, liquid oil (conventional crude) is often found in porous rock formations and can be extracted through relatively simpler well - based extraction as it is already in a fluid state that can flow towards wells under pressure or with pumping.
2. Upgrading Process: Bitumen from oil sands is a heavy hydrocarbon with high viscosity, high sulfur content, and high density. It needs to be upgraded to a synthetic crude oil (syncrude) that is more similar to conventional crude. This upgrading involves processes like cracking (to break long hydrocarbon chains), desulfurization (to remove sulfur), and hydrogenation. Conventional liquid oil may require less extensive refining as it is already a lighter, more refined - like product in its natural state.
3. Environmental and Energy Inputs: Extracting and upgrading oil from oil sands requires large amounts of energy (for mining, processing, and upgrading) and water. The energy is often used to heat water for steam in in - situ methods or to power mining equipment. The water usage is also significant for separating the bitumen from the sand - clay mixture. Conventional oil production generally has lower energy and water requirements per unit of oil produced.

Answer:

Producing oil from oil sands is more complex because: 1. Oil sands have bitumen mixed with sand, clay, and water, requiring complex extraction (mining or in - situ) unlike the simpler well - based extraction of liquid oil. 2. Bitumen from oil sands needs extensive upgrading (cracking, desulfurization, hydrogenation) to become usable syncrude, while liquid oil needs less refining. 3. Oil sand production needs more energy (for extraction/upgrading) and water, increasing complexity.