Low-Temperature Separation Without Hydrate Inhibitor.

The basic unit for low-temperature separation without hydrate inhibitor includes essentially a choke, separator. and heat-exchange coils. Assuming that the inlet wellstream contains a minimum amount of free water and is of sufficient temperature to prevent formation of hydrates upstream of the choke, the operation is as follows. Technical Data used in the field explained in petroleum courses in Islamabad.

The wellstream enters the unit through the heat-exchange coil. where it is cooled through heat exchange with the liquid external to the coil. The well stream then passes through an adjustable choke used to control the flow rate through the system and establish a means for introducing the necessary pressure drop. The turbulence and temperature drop created by the expansion across the choke cause the formation of hydrates and the condensation of the liquefiable hydrocarbons. The hydrates and condensate are separated from the gas by means of centrifugal force, normally generated by locating the choke tangential to the shell of the separator, and by gravity. Some more details of petroleum courses in Islamabad are as under

The hydrates and condensate collect in the bottom of the separator where they absorb heat from the inlet coil, causing the hydrates to be melted. The liquid level is maintained by a level controller such that the coils are always submerged in the liquid.

Two possible operating problems might occur in this simple system. Either the wellstream could be near the hydrate temperature on entering the coil and further cooling would create hydrates upstream of the choke, or there is an insufficient amount of the liquid bottoms causing hydrates to build up inside the separator. In either case the system will malfunction. To use low-temperature separation successfully, the pressure of the gas upstream of the choke must be approximately twice the pressure in the low-temperature separator. Certainly, the higher the pressure upstream of the choke the lower the temperature that can be achieved in the low-temperature separator.

The common solution to this problem is to install an indirect heater upstream of the low-temperature separator. The indirect heater temperature would be maintained at a level to ensure wellstream gas temperatures above the hydrate temperature. Heat transfer is accomplished by flowing the wellstream through the coils in the indirect heater. The gas temperature is controlled by a thermostat located in the outlet end of the coil. A second thermostat can be located in the liquid section of the low-temperature separator to override the heater controls in the event the liquid temperature is too low. TSK Training for Skills and Knowledge is the best institute in Rawalpindi Islamabad for Pakistani Students who wants to join  petroleum courses in Rawalpindi.