Extracting oil from shale deposits primarily involves heating the rock to release the trapped organic material, known as kerogen, which converts into shale oil.
There are two main approaches described for extracting oil from shale deposits: ex situ and in situ.
Ex Situ Extraction
The ex situ process involves removing the oil shale from the ground before processing. This is the more established method.
Here's a breakdown of the steps:
- Mining: Oil shale is first extracted from the earth. This can be done through either surface mining or underground mining, depending on the depth and location of the deposit.
- Crushing: The mined rock is then crushed into smaller pieces. This increases the surface area, making the subsequent heating process more efficient.
- Retorting (Heating): The crushed shale is then retorted, which means it is heated in a controlled environment. This heating breaks down the kerogen within the shale rock, converting it into liquid shale oil and gas.
- Refining: The released shale oil is then refined. This step involves removing impurities, such as sulfur, to produce a usable crude oil product.
In Situ Extraction
In situ is a newer, experimental method of extracting shale oil. Instead of mining the rock, this process involves heating the oil shale deposit underground. This heating releases the oil and gas directly within the deposit, which can then be extracted via wells, similar to conventional oil and gas production.
Summary Table:
| Method | Location of Processing | Steps | Status |
|---|---|---|---|
| Ex Situ | Surface | Mining, Crushing, Heating (Retorting), Refining | Established |
| In Situ | Underground | Heating rock in place, Extracting released oil/gas | Experimental |
Both methods aim to convert the solid kerogen in shale into usable liquid hydrocarbons, but they differ significantly in how the shale rock is handled before the heating step.
