Such as to drive the hydrocarbons to the surface. A reservoir is completely or partially isolated from the pressure regime in the surrounding rock. As oil is produced the gas cap above it expands. As it expands it loses energy. The temperature and pressure in the reservoir drop until eventually there is not enough energy left to drive the drive the oil out. Gas drive is not an efficient long term production driver.
Drilling fluid whose bulk, unpressurized density is reduced as a small volume of gas displaces an equivalent volume of liquid. A mud that has gas (air or natural gas) bubbles in it
Number of cubic feet of gas produced per barrel of oil
Derived annually by dividing gross natural gas withdrawals from gas wells by the number of producing gas wells on December 31 and then dividing the quotient by the number of days in the year.
A well completed for production of natural gas from one or more gas zones or reservoirs. Such wells contain no completions for the production of crude oil
Generating electricity with gas turbines is more expensive than with stream driven units but the gas turbines can be started and stopped more quickly, so that gas turbines are used during peak electricity consumption hours
