You must write out your equations with all appropriate units and provide a nomenclature for all variables in your equations. Use a yellow highlighter to indicate your answer once you have completed your analysis. You must scan in your solution papers immediately at the conclusion of the exam. Make sure to number your pages appropriately and indicate which problem you are working on each page.
Clearly state all assumptions.
Please provide your answers in a blue or a green colored text.
You may use this document to write your answers. Please make sure that you write your answers found in the analytical questions on this document with proper units.
A centrifugal pump takes suction from a storage tank and the vapor pressure of the liquid contained in the tank is ~ 100 psig. The pump suction is 28 feet below the liquid level in the tank. The API gravity of the fluid in the tank was found to 70.6 and the pressure losses in the suction piping due to friction is 5 psi. The liquid is pumped into a pipeline with an outlet pressure of 500 psig. The pressure drop due to friction in the pipe is 550 psi. Calculate the suction and discharge head for this pump? What is the water and break horsepower required for this pump, assuming an efficiency of 0.71? Assume the pump is moving 10,000 B/D of liquid What is the elevation difference between the tank and the pump with a given NPSHR = 56 feet? Assume the pressure drop in the suction pipe is 1.0 psi at the design flowrate and the design margin (NPSHA/NPSHR) = 1.75 From part “c” it was found the height placement of the liquid tank is unrealistic and the maximum height for the tanks must be at a height no more than 30 feet. Therefore, what pressure must the tank be pressurized above the liquid vapor pressure to accomplish this task? (Hint: Think about part “c” and the variables that make up the equation)
A mature gas reservoir has declined in pressure over many years. A depletion compressor is to be installed to boost the gas from wellhead pressure to gathering system pressure. The compressor design conditions are as follows:
zavg ~ 0.9
Isentropic Exponent Estimation
Calculate the polytropic head? Calculate the compressor power? Estimate the compressor discharge temperature in oF? If the temperature was found to be greater than 350 oF what type of compressor would you recommend? A natural gas pipe line, made of 20 inch schedule 40 pipe is 75 miles long. The inlet pressure is 1285 psig and the outlet pressure is 285 psig and the average temperature is 68 oF. The gas consits of 75% C1, 21% C2 and 4% C3. Assume there is no elevation change over the 75 miles. Also assume the gas flow rate is fully turbulent and use the Nikuradse 1933 correlation to estimate the friction factor.
Pipe dimensions: I.D. = 18.81” and ϵ =0.00002 feet.
Assume the z @ 1285 psig = 0.68 and z @ 285 psig = 0.93 and μ = 0.015 cP and the γ_gas =0.7.
Find the flow rate in MMscfd, Reynolds number and pipe veloctiy using the Simplified gas equation.
Determine the MEG Injection Rate Determination of MEG Injection Rate A water-saturated, sweet natural gas (SG = 0.65) flows in an offshore pipeline with an inlet pressure and temperature of 10 MPa and 37.7 oC (100 oF), respectively, and a flow rate of 0.5*106 std m3/d. The outlet pressure and temperature of the pipeline are 7.3 MPa and 5 oC (41 oF), respectively. Use the GPSA gas gravity method charts in the appendix to determine the risk of hydrate formation along the pipeline, and then determine the subcooling. Given a high risk of hydrate formation, determine the required volumetric injection rate (m3/d) of commercially available 70 wt% MEG to mitigate the hydrate formation, given that the allowable dilution of MEG is 10 wt%. The MEG density at 25 oC is 1112.1 kg/m3. From “ii” how many barrels of MEG is needed per day? Pipe Erosion Prediction An oil well produces a two-phase flow mixture through a flowline to a manifold. Given the following input data, determine whether pipe erosion will occur using the API RP 14 E for: Clean service Erosive service. m ̇_s=50 kg/d ρ_L=1000 kg/m^3 ρ_g=100 kg/m^3 ν_SL=3 m/s ν_Sg=10 m/s d_p=5 cm