Question

Discuss two sources of petroleum that will be available after conventional wells go dry.

Short answer

Two sources of petroleum after conventional wells are oil sands and oil shale.

Step-by-step solution

Identify Alternative Sources of Petroleum

When conventional wells go dry, alternative sources of petroleum that can be considered include oil sands and oil shale. These sources are abundant in certain regions and can provide significant amounts of petroleum.

Explain Oil Sands

Oil sands are a mixture of sand, water, clay, and bitumen, a heavy black viscous oil. Extraction and processing technologies, like surface mining and thermal in-situ methods, are used to separate and refine bitumen into synthetic crude oil. Countries like Canada have vast reserves of oil sands.

Explain Oil Shale

Oil shale is a sedimentary rock that contains kerogen, a precursor to oil, which is converted into liquid hydrocarbons through a process called retorting. This involves heating the shale to high temperatures to extract the oil. The United States holds large deposits of oil shale, especially in the Green River Formation.

Key concepts

Oil Sands

Oil sands, often called tar sands, are a mixture that contains sand, water, clay, and thick, sticky bitumen. This bitumen is not like the usual crude oil we get from conventional wells. It is heavier and requires special technologies for extraction and processing. Some of the common methods used include surface mining and thermal in-situ techniques.
Surface mining involves digging up large areas of land to physically separate the bitumen from the sand. On the other hand, thermal in-situ methods use steam and heat to liquefy the bitumen so that it can be pumped to the surface. This process is less intrusive to the land compared to mining.
Oil sands are considered a significant petroleum source because places like Canada have large reserves, particularly in Alberta. With advances in technology, extracting oil from sands becomes increasingly efficient, making it a vital alternative source of energy when conventional wells run dry.

Oil Shale

Oil shale is another alternative petroleum source, but it is different from oil sands. It is a type of sedimentary rock that harbors an organic material called kerogen. When heated, kerogen breaks down into usable hydrocarbons, which can be processed into synthetic crude oil.
The process to extract oil from oil shale is known as retorting. In this process, the rocks are heated at high temperatures, causing the kerogen to decompose into oil. This extracted oil can then be refined further to produce usable petroleum products.
The United States, particularly in the Green River Formation, contains enormous deposits of oil shale. Although the extraction process is complex and requires significant energy, ongoing research and technology enhancements continue to make oil shale a more viable energy source in the future.

Conventional Wells

Conventional oil wells have been the traditional source of petroleum. These wells extract oil from underground reservoirs where the oil is naturally pooled. Drilling techniques are used to tap into these reservoirs, allowing petroleum to be pumped to the surface.
Conventional wells are often favored because the extraction process is less costly and demanding compared to alternative sources like oil sands and oil shale. The oil found in these wells is typically lighter and requires less processing before being refined into products such as gasoline or diesel.
However, with the increasing demand for oil and depletion of easy-to-reach reserves, the reliance on conventional wells is shifting. It's crucial to explore alternative sources like oil sands and oil shale to supplement our energy needs in a sustainable manner.