Two-Phase flow In a Horizontal Pipe

While working for an oil company you are asked to produce a report on a two-phase flow problem. A mixture of oil and gas is to be pumped along a 100km long pipe from one distribution point to another. Your brief states that the nominal maximum pressure allowable in the pipe is 80bar and if the pressure falls below 40bar then a pumping station will be required to re-pressurise the supply back to 80bar. The flow information at the start of the pipe for the application is as follows:

                                                                                    Gas                 Oil

Pressure (Bar)                                                              80.0                80.0

Temperature (K)                                                            280                 280

Density (kg/m³)                                                            80.0                900.0

Kinematic Viscosity (m²/s)                                          8.3x10^-6             5x10^-4

Maximum Volumetric Flowrate (m³/s)                             0.23                0.2

Minimum  Volumetric Flowrate (m³/s)                            0.1                   0.1

In your report you should state what diameter of pipe you wish to use, how many pumping stations may be required and discuss the various engineering considerations that must be taken into account. At least one typical calculation is required and if possible predict the type of flow that will occur in the pipe.

State, and justify, any assumptions that you make.