How does shale oil extracted from oil shale differ from tight oil extracted from shale formations?

The terms "shale oil" and "tight oil" are often confused, but they refer to distinct geological resources and extraction processes.12

Shale Oil
Shale oil is a synthetic crude oil produced from oil shale, a sedimentary rock containing solid organic matter called kerogen. Because this rock has not been subjected to the natural heat required to convert kerogen into liquid petroleum, the oil must be extracted through pyrolysis—a process involving intense heating (often around 500 °C) to break down the kerogen into liquid and gaseous hydrocarbons.312

Tight Oil
Tight oil is naturally occurring crude oil trapped within dense, impermeable rock formations, such as shale or dolomite, that have very low porosity and permeability. Unlike oil shale, the organic matter in these formations has already been converted into oil by natural geological processes. Extraction requires advanced technologies, most notably hydraulic fracturing (fracking) and horizontal drilling, to release the trapped oil.32

While the industry often uses the term "shale oil" to refer to tight oil due to their similar geological settings, they remain fundamentally different in their chemical origin and the methods required for recovery.312