Quiz 9 PDF

Quiz Answers 1. Which drive mechanism is primarily used for gas reservoirs? A. Solution Gas Drive B. Immiscible Water and/or Gas injection C. Pressure depletion D. Water-drive Answer: Pressure depletion (C) Gas reservoirs primarily rely on pressure depletion as the drive mechanism. 2. What is the pu...

Quiz Answers 1. Which drive mechanism is primarily used for gas reservoirs? A. Solution Gas Drive B. Immiscible Water and/or Gas injection C. Pressure depletion D. Water-drive Answer: Pressure depletion (C) Gas reservoirs primarily rely on pressure depletion as the drive mechanism. 2. What is the purpose of tertiary recovery in reservoir development? A. To increase the reservoir's energy B. To reduce hydrocarbon viscosity C. To change the flow paths D. To improve sweep and drainage efficiency Answer: To increase the reservoir's energy (A) Tertiary recovery aims to increase the reservoir's energy in order to enhance oil recovery. 3. Which method is NOT used in tertiary recovery? A. Chemical flooding B. Gas Injection C. Horizontal wells D. Water Injection Answer: Horizontal wells (C) Horizontal wells are not a method used in tertiary recovery. 4. Which factor is associated with viscous fingering at high Mobility ratios? A. Mobility = 2.4 B. Break-through at 0.7 PV C. Mobility = 71 D. Break-through at 0.4 PV Answer: Mobility = 2.4 (A) Viscous fingering occurs at high Mobility ratios, which is indicated by a Mobility value of 2.4. 5. What is the range of macroscopic sweep efficiency mentioned in the text? A. 0.4-71 PV B. 0.1-0.7 PV C. 22-25 PV D. 1-2.4 PV Answer: 0.1-0.7 PV (B) The text mentions that macroscopic sweep efficiency can be on the order of 1km, indicating a range of 0.10.7 PV. 6. What is the average recovery factor for the largest Norwegian oil fields? A. 47% B. 71% C. 22% D. 100% Answer: 47% (A) According to the Norwegian Petroleum Directorate, the largest Norwegian oil fields have an expected recovery factor averaging 47%. 7. Which drive mechanism requires a reservoir in communication with an aquifer? A. Depletion drive B. Water drive C. Gas cap drive D. Solution gas drive Answer: Water drive (B) Water drive requires a reservoir in communication with an aquifer that provides the bulk of the energy. 8. What is the primary recovery factor range for solution drive? A. Greater than 75% B. 20-50% C. 5-30% D. 35-75% Answer: 5-30% (C) The primary recovery factors for solution drive range from 5-30%. 9. What is the primary recovery factor range for gas cap drive? A. 5-30% B. Greater than 75% C. 35-75% D. 20-50% Answer: 20-50% (D) The primary recovery factors for gas cap drive range from 20-50%. 10. What is the primary recovery factor range for water drive? A. 20-50% B. 35-75% C. Greater than 75% D. 5-30% Answer: 35-75% (B) The primary recovery factors for water drive range from 35-75%. 11. Which method is used in primary recovery? A. Water Injection B. Miscible flooding C. Depletion drive D. Gas Injection Answer: Depletion drive (C) Primary recovery in oil reservoirs is achieved through depletion drive, where the reservoir's own energy is used. 12. What is the typical compressibility of gas compared to water? A. Gas compressibility is lower than water B. Gas and water have similar compressibility C. Compressibility does not affect gas production D. Gas compressibility is higher than water Answer: Gas compressibility is lower than water (A) Gas compressibility is much higher than water, which allows gas to move faster for the same pressure drop. 13. What is the gas formation volume factor (BG)? A. The ratio of surface volume to reservoir volume B. The volume of gas in the reservoir C. The volume of gas at the surface D. The ratio of reservoir volume to surface volume Answer: The ratio of reservoir volume to surface volume (D) The gas formation volume factor (BG) is the ratio of the volume of gas in the reservoir to the volume of gas at the surface. 14. What is the main challenge in gas field development? A. Improving sweep and drainage efficiency B. Reducing hydrocarbon viscosity C. Increasing reservoir energy D. Ensuring a sustainable plateau production rate Answer: Ensuring a sustainable plateau production rate (D) The main challenge in gas field development is to ensure a long, sustainable plateau production rate required for a good sales price. 15. Which drive mechanism is associated with pressure depletion in gas reservoirs? A. Gas Cap Drive B. Solution gas Drive C. Immiscible Water and/or Gas injection D. Water-drive Answer: Gas Cap Drive (A) Gas Cap Drive is the drive mechanism associated with pressure depletion in gas reservoirs. 16. Which recovery method involves changing the flow paths and fluid properties of the reservoir? A. Secondary Recovery B. Primary Recovery C. Tertiary Recovery D. Water Injection Answer: Tertiary Recovery (C) Tertiary Recovery involves changing the flow paths and fluid properties of the reservoir. 17. What is the primary recovery method that utilizes the reservoir's own energy? A. Primary Depletion B. Water Alternating Gas Injection C. Gas Injection D. Water Injection Answer: Primary Depletion (A) Primary Depletion is the primary recovery method that utilizes the reservoir's own energy. 18. Which drive mechanism requires a reservoir in communication with an aquifer? A. Water drive B. Gas cap drive C. Depletion drive D. Solution gas drive Answer: Water drive (A) Water drive requires a reservoir in communication with an aquifer that provides the bulk of the energy. 19. What is the primary recovery factor range for solution drive? A. 35-75% B. 50-80% C. 20-50% D. 5-30% Answer: 5-30% (D) Primary recovery factors for solution drive range from 5-30%. 20. What is the primary recovery factor range for gas cap drive? A. 35-75% B. 20-50% C. 5-30% D. 50-80% Answer: 20-50% (B) Primary recovery factors for gas cap drive range from 20-50%. 21. What is the primary recovery factor range for water drive? A. 35-75% B. 20-50% C. 5-30% D. 50-80% Answer: 35-75% (A) Primary recovery factors for water drive can range from 35-75%. 22. Which recovery mechanism is primarily used in the largest Norwegian oil fields? A. Tertiary recovery B. Water drive C. Solution drive D. Gas cap drive Answer: Water drive (B) The text mentions that the largest Norwegian oil fields have an expected recovery factor averaging 47%, which indicates the primary recovery mechanism is water drive. 23. What is the range of pore volumes injected for different mobility ratios mentioned in the text? A. 0.4 to 71 B. 0.15 to 2.4 C. 1.0 to 71 D. 0.1 to 0.7 Answer: 0.4 to 71 (A) The text mentions different mobility ratios (M) of 0.15, 1.0, 2.4, and 71, and their corresponding breakthroughs at different pore volumes, indicating the range of pore volumes injected for different mobility ratios is 0.4 to 71. 24. What is the average recovery factor for the 25 largest Norwegian oil fields? A. 71% B. 22% C. 47% D. 100% Answer: 47% (C) The text states that the 25 largest Norwegian oil fields have expected recovery factors averaging 47%. 25. Which drive mechanism is commonly used for gas reservoirs? A. Solution gas drive B. Water drive C. Deletion drive D. Compaction drive Answer: Solution gas drive (A) Gas reservoirs are commonly produced using the solution gas drive mechanism, where the expansion of gas aids in the extraction of gas from the reservoir. 26. What is the typical gas compressibility compared to water? A. 3x10-6 psi-1 B. 10-5 psi-1 C. 0.01cp D. 5x10-4 psi-1 Answer: 5x10-4 psi-1 (D) The typical compressibility of gas is 5x10-4 psi-1, which is 200 times higher than water (3x10-6 psi-1) and 50 times lower than oil (10-5 psi-1). 27. What is the gas formation volume factor (BG)? A. The volume in barrels that one standard cubic feet of gas occupies as free gas in the reservoir. B. The volume of gas in the reservoir. C. The volume of gas at the surface. D. The ratio of reservoir volume to stock-tank gas volume. Answer: The volume in barrels that one standard cubic feet of gas occupies as free gas in the reservoir. (A) The gas formation volume factor (BG) is the volume in barrels that one standard cubic feet of gas occupies as free gas in the reservoir. It is measured in rbl/scf. 28. Which gas field is currently being considered as a potential CO2 sequestration site and/or storage site for green hydrogen? A. Seven Heads B. Kinsale Head C. Ballycotton D. SW Kinsale Answer: Kinsale Head (B) The Kinsale gas field is currently being discussed as a potential CO2 sequestration site and/or storage site for green hydrogen. It has already produced over 2 TCF of gas during its 42-year production life. 29. Which drive mechanism is commonly used for primary recovery in gas reservoirs? A. Pressure depletion B. Water drive C. Solution gas drive D. Gas cap drive Answer: Pressure depletion (A) Primary recovery in gas reservoirs commonly relies on pressure depletion, where the natural pressure of the reservoir is used to drive the gas to the surface. 30. What is the primary recovery factor range for water drive? A. 70-80% B. 10-20% C. 30-40% D. 50-60% Answer: 50-60% (D) The primary recovery factor range for water drive is typically between 50-60%. Water injection is used to displace the oil and improve recovery from the reservoir. 31. What is the main challenge in gas field development? A. Limited availability of gas reserves B. High cost of gas production C. Low permeability of gas reservoirs D. High compressibility of gas Answer: Low permeability of gas reservoirs (C) The main challenge in gas field development is the low permeability of gas reservoirs. This makes it difficult for the gas to flow through the reservoir and be extracted efficiently. 32. Which drive mechanism requires a reservoir in communication with an aquifer? A. Depletion drive B. Water drive C. Solution gas drive D. Gas cap drive Answer: Water drive (B) Water drive requires a reservoir in communication with an aquifer to provide the bulk of the energy. 33. What is the primary recovery factor range for solution drive? A. 5-30% B. 20-50% C. 35-75% D. 50-80% Answer: 5-30% (A) The primary recovery factor range for solution drive is 5-30%. 34. Which factor is associated with viscous fingering at high Mobility ratios? A. Relative permeability B. Pore-scale displacement efficiency C. Sweep efficiency D. Mobility ratio Answer: Mobility ratio (D) Viscous fingering is associated with high Mobility ratios. 35. What is the primary recovery factor range for water drive? A. 5-30% B. 20-50% C. 35-75% D. 50-80% Answer: 35-75% (C) The primary recovery factor range for water drive is 35-75%. 36. Which drive mechanism is commonly associated with pressure depletion in gas reservoirs? A. Gas cap drive B. Solution drive C. Water drive D. Aquifer drive Answer: Gas cap drive (A) Gas cap drive is commonly associated with pressure depletion in gas reservoirs. It occurs when the gas cap expands as the reservoir is produced, pushing the oil towards the production wellbore. 37. What is the primary recovery factor range for gas cap drive? A. 10-20% B. 50-60% C. 70-80% D. 30-40% Answer: 50-60% (B) The primary recovery factor range for gas cap drive is typically around 50-60%. This means that only about 50-60% of the original oil in place can be recovered using this drive mechanism. 38. What is the purpose of tertiary recovery in reservoir development? A. To improve sweep efficiency B. To reduce formation damage C. To maximize primary recovery D. To increase gas mobility Answer: To improve sweep efficiency (A) The purpose of tertiary recovery in reservoir development is to improve sweep efficiency. It involves injecting additional fluids or energy into the reservoir to push the remaining oil towards the production wells and increase overall recovery. 39. Which drive mechanism is commonly used for oil reservoirs with an initial gas cap? A. Solution gas drive B. Depletion drive C. Compaction drive D. Water drive Answer: Depletion drive (B) Depletion drive is commonly used for oil reservoirs with an initial gas cap. It involves the expansion of the gas cap to enhance the drive mechanism. 40. Which gas field in the North Celtic Sea Basin has been used for gas storage and is currently being considered as a potential site for CO2 sequestration and/or storage of green hydrogen? A. SW Kinsale B. Kinsale Head C. Seven Heads D. Ballycotton Answer: SW Kinsale (A) SW Kinsale has been used for gas storage and is currently being considered as a potential site for CO2 sequestration and/or storage of green hydrogen. 41. What is the typical gas compressibility compared to water? A. 200 times higher B. 50 times higher C. 200 times lower D. 50 times lower Answer: 50 times lower (D) The typical gas compressibility is 50 times lower compared to water. This favorable mobility allows gas to move 50 times quicker for the same pressure drop than water. 42. What is the gas formation volume factor (BG) for gas reservoirs? A. 100 rbl/scf B. 1000 rbl/scf C. 1 rbl/scf D. 10 rbl/scf Answer: 1000 rbl/scf (B) The gas formation volume factor (BG) for gas reservoirs is typically 1000 rbl/scf, meaning that one standard cubic feet of gas occupies 1000 barrels in the reservoir.