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How do clay minerals help release hydrocarbons from a source rock?

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Multiple large offshore petroleum oil rigs with cranes and equipment stand in the ocean, connected by walkways above the water. — petroleum Liquid petroleum (crude oil)—which is refined into gasoline, diesel, heating fuels, asphalt, plastics, and other useful chemical compounds—is often extracted from the ground using a series of drills and pumps.

Clay minerals play a critical role in the primary migration of hydrocarbons from source rocks through the process of dehydration. As sediments are buried and subjected to increasing temperatures, clay minerals undergo a transformation where they lose water molecules that were previously held within their molecular lattices.1

This dehydration process expels water from the compacting clay, and the newly generated hydrocarbons become mobile enough to leave the source beds by traveling in solution, suspension, or emulsion with this expelled water. This movement of hydrocarbons through the narrow pores and capillaries of the source rock is a fundamental step in the formation of petroleum accumulations.1