Reservoir Drives and Production Decline Rates in Petroleum Engineering
Which of the following lists reservoir drives in order of fastest to slowest production decline rate?
A) Water drive, gas cap drive, solution gas drive
B) Gas cap drive, solution gas drive, water drive
C) Solution gas drive, water drive, gas cap drive
D) Solution gas drive, gas cap drive, water drive
Final answer:
Answer:
The order of reservoir drives from the fastest to slowest production decline rate is Solution gas drive, Gas cap drive, and Water drive, with Solution gas drive exhibiting the fastest rate due to the rapid pressure depletion as the dissolved gas is produced.
Explanation:
The question involves understanding the different types of reservoir drives and their impact on the production decline rate in petroleum engineering.
The correct order of reservoir drives from fastest to slowest production decline rate is:
Solution gas drive
Gas cap drive
Water drive
When a reservoir is driven by solution gas drive, the decline rate is typically rapid because the oil production is driven by the expansion of gas that was originally dissolved in the oil. Once the pressure drops, this gas expands and pushes the oil towards the wellbore, but as the reservoir depletes, the drive energy quickly diminishes, leading to a fast production decline.
A gas cap drive involves the expansion of gas from a gas cap overlying the oil. Although it provides a strong driving force initially, decline rates can vary because less energy is available to move the oil over time. Therefore, the decline rate is typically slower than that of the solution gas drive.
The water drive scenario, where water influx maintains reservoir pressure, typically exhibits the slowest decline rate because the energy for production can be markedly sustained over time as water moves in to displace oil.
Therefore, the correct answer is D) Solution gas drive, gas cap drive, water drive.