Pressure Calculations 1 Pressure Calculations 1 / 15 The mud above a 500-foot long cement plug is displaced with a brine. Mud below the plug = 11.5 ppg Top of cement plug = 7500 ft Brine = 8.6 ppg What is the pressure differential across the cement plug? 1131 psi 1206 psi 1430 psi 3354 psi 2 / 15 Considering the options below, what would be the most appropriate procedure when tripping back to bottom with a heavy pill in the annulus? Don't move the pill once it is preventing the well from flowing The heavy pill will increase the chance of swabbing and must be removed Circulate the pill out in stages to reduce the chance of surging the well Circulate the pill out using a heavier fluid to kill the well 3 / 15 Compared to the pressure loss (friciton) around the BHA, the friction around the drill pipe will be: Less More There is no way to know The Same 4 / 15 After experiencing total losses while drilling, the pumps were stopped and hole filled up to the top with water. Mud weight = 11 ppg Brine water weight = 8.6 ppg Height of water column in the annulus = 250 ft What is the reduction in bottom hole pressure? 31 psi There is no change in bottom hole pressure 143 psi 112 psi 5 / 15 What is the definition of Permeability? The ability of formation fluids to flow through the rock The pressure in the pore space of the formation The amount of void spaces in the formation The total amount of formation fluids in the well 6 / 15 What is the definition of Porosity? The pressure in the pore space of the formation The amount of void spaces in the formation The ability of formation fluids to flow through the rock The total amount of formation fluids in the well 7 / 15 What is the pressure gradient of a 12.2 ppg fluid? 2.074 psi/ft 0.6344 psi/ft It depends on the TVD of the well It depends on the amount of fluid in the well 8 / 15 Using the information below, answer the following question. Well TVD = 10 000 ft Well MD = 12 000 ft Shoe TVD/MD = 7500 ft MW = 10 ppg Drill String Pressure Loss (friction) = 2000 psi Annular Pressure Loss (friction) = 500 psi What is the ECD at the bottom of the well? 10 ppg 13.8 ppg 11 ppg 14.8 ppg 9 / 15 What happens to bottom hole pressure (BHP) when the pumps are stopped on conventional drilling? The BHP will increase The BHP will stay the same The BHP will stay the same The BHP will decrease 10 / 15 What is the well condition? MW = 12.2 ppg Well TVD / MD = 12000 ft / 13000 ft Formation Pressure = 10,000 psi Underbalanced Overbalanced There is no way to know Balanced 11 / 15 Calculate the hydrostatic pressure of an 12.3 ppg fluid at 8000 ft MD (6200 ft TVD)? 4565 psi 4020 psi 3966 psi 5117 psi 12 / 15 Use the information below to answer the following question: Formation Pressure = 8500 psi at 12000′ TVD /14000′ MD MW = 12.2 ppg Drill String Pressure Loss = 2200 psi Annular Pressure Loss = 550 psi How much pressure is needed to balance the well against the formation during a connection? 382 psi 888 psi Zero 338 psi 13 / 15 Use the information below to answer the following question: Drilling ahead at 9000 ft TVD / 10 000 ft MD Formation Pressure = 5500 psi Mud Weight = 11.5 ppg Drill String Pressure Loss = 2000 psi Annular Pressure Loss = 500 psi What is the well condition? Balanced with pumps off Overbalanced with pumps on and underbalanced with pumps off Underbalanced with pumps on Balanced with pumps on 14 / 15 Use the information below to answer the following question: 500-foot long cement plug Mud above the plug = 8.6 ppg Top of cement plug = 9500 ft TVD Formation pressure below the plug = 5460 psi If the plug fails and the bottom of the well is exposed to the atmosphere, what would happen downhole? Loss of fluid Well would remain static There is no way to know Well would flow 15 / 15 What is happens to the Annular Pressure Loss (APL) if the pump rate is reduced from 40 SPM to 30 SPM while pumping a kick out through the vertical section of the well? The APL will decrease The APL will stay the same The APL will increase There is no way to know Your score is LinkedIn Facebook Twitter VKontakte
