Explain the following terminologies as applied to oil and gas: Reservoir rock Cap rock Source rock Reservoir

Reservoir rock: Reservoir rock refers to a porous and permeable rock formation that contains oil or gas in underground reservoirs. This rock is able to store and transmit hydrocarbons, allowing for the extraction of oil and gas through drilling.

Cap rock: Cap rock, also known as seal rock, is a impermeable rock formation that lies above a reservoir rock. It acts as a barrier, preventing the oil or gas from escaping to the surface. Cap rock is essential in trapping hydrocarbons in the reservoir and preventing their migration to other areas.

Source rock: Source rock is a type of organic-rich rock formation that contains the original material from which oil and gas are formed. Over time, the organic material in the source rock undergoes heat and pressure, transforming into hydrocarbons. These hydrocarbons then migrate from the source rock into reservoir rocks where they are trapped.

Reservoir: In the context of oil and gas, a reservoir refers to a subsurface rock formation that contains a significant amount of oil or gas. Reservoirs are typically porous and permeable, allowing for the storage and flow of hydrocarbons. Oil and gas companies drill wells into reservoirs to extract the resources for production.

Reservoir Rock

- Definition: A porous and permeable rock formation that contains and transmits hydrocarbons (oil and gas).
- Characteristics:
- High porosity, allowing the storage of hydrocarbons.
- High permeability, allowing hydrocarbons to flow easily through the rock.
- Presence of seals or barriers to prevent hydrocarbons from escaping the reservoir.

Cap Rock

- Definition: An impermeable rock formation that traps hydrocarbons within a reservoir by forming a seal above it.
- Characteristics:
- Low porosity and permeability, preventing hydrocarbons from migrating upwards.
- Ductile or plastic, to ensure a tight seal over time.

Source Rock

- Definition: A rock formation that contains organic matter that can generate hydrocarbons through thermal maturation.
- Characteristics:
- Rich in organic material, such as plant or animal remains.
- Undergoes heating and pressure over time, causing organic matter to transform into hydrocarbons.

Reservoir

- Definition: A combination of reservoir rock, cap rock, and source rock that contains and traps hydrocarbons for commercial extraction.
- Characteristics:
- Includes all necessary components for hydrocarbon storage and entrapment.
- May contain multiple layers of different rock types.
- Bounded by faults, structural traps, or stratigraphic traps that prevent hydrocarbons from escaping.