Final answer:
Water and immiscible gas are used in oil production to maintain pressure in a reservoir by injecting water under high pressure and fracturing the underground rock using pressurized fluids.
Step-by-step explanation:
In oil production, fluids like water and immiscible gas are used to maintain pressure in a reservoir. This is done through various techniques, including injecting water under high pressure and fracturing the underground rock using pressurized fluids.
These techniques help push or pull the oil out of its porous rock, allowing for extraction.