For decades,some geological formations have been drilled with a drilling fluid that exerted a bottom-hole pressure less than the formation pressure,allowing formation fluids-oil,gas and water-to flow from the reservoi...For decades,some geological formations have been drilled with a drilling fluid that exerted a bottom-hole pressure less than the formation pressure,allowing formation fluids-oil,gas and water-to flow from the reservoir into the well bore while drilling proceeds.A growing number of Iranian case histories have shown that when UBD is applied in the right reservoir with the proper planning,well productivity can be orders of magnitude greater than with a conventional well drilled into the same formation.Wells drilled underbalanced have been proven to add展开更多
Underbalanced drilling(UBD) is defined as a drilling operation in which circulating drilling fluid pressure is maintained to be lower than reservoir pore pressure.Underbalanced drilling may improve drilling efficiency...Underbalanced drilling(UBD) is defined as a drilling operation in which circulating drilling fluid pressure is maintained to be lower than reservoir pore pressure.Underbalanced drilling may improve drilling efficiency and enhance well productivity. Approximately 90%of the discovered fields in Iran are in carbonate reservoirs putting Iran as one of the largest carbonate producers in the world.Under-展开更多
文摘For decades,some geological formations have been drilled with a drilling fluid that exerted a bottom-hole pressure less than the formation pressure,allowing formation fluids-oil,gas and water-to flow from the reservoir into the well bore while drilling proceeds.A growing number of Iranian case histories have shown that when UBD is applied in the right reservoir with the proper planning,well productivity can be orders of magnitude greater than with a conventional well drilled into the same formation.Wells drilled underbalanced have been proven to add
文摘Underbalanced drilling(UBD) is defined as a drilling operation in which circulating drilling fluid pressure is maintained to be lower than reservoir pore pressure.Underbalanced drilling may improve drilling efficiency and enhance well productivity. Approximately 90%of the discovered fields in Iran are in carbonate reservoirs putting Iran as one of the largest carbonate producers in the world.Under-
