a) What does choked flow mean and what are the two flow regimes that can occur at the choke? [5 Marks] b) Describe issues that can occur at the choke of a well producing natural gas due to pressure drop and temperature drop. [7 Marks] c) Natural gas flows through the converging-diverging throat of a wellhead choke with a cross-sectional area of 4cm2. The downstream conditions from the choke have a pressure of 400kPa, a temperature of 359K and a flow velocity of 729ms1. Using the information and equations provided; determine: (i) If the nozzle is choked. [3 Marks] (ii) The cross-sectional area of the downstream pipe ( 3 significant figures). [3 Marks] (iii) The stagnation pressure and temperature ( 4 significant figures). [4 Marks] (iv) The mass flow rate through the choke (4 significant figures). [3 Marks] Page 7 of 9