Sizing Surface Production Flow line Insulation Thickness for a Desired Output Temperature

Oil and gas is transported from the wellheads to the gathering stations through pipelines called surface production flowlines. Flow-lines are located at the oil and gas well site and tied to specific wells. Flow-line may be a metallic pipe or a hose. Flow lines may be in a land or subsea well field and may be buried or at grade on the surface of land or seafloor. Most flow lines are very short in length but others may be run for kilometres in larger well fields. Usually, external environment of a surface production flow-line is at lower temperature compared to the flowing fluid temperature in the production flow-line. The interaction of the internal and external temperatures of the oil and gas surface production flowline is a major cause of temperature drop in flow-line. Undesirable and excessive temperature drops must be prevented in oil and gas production flow-line by suitable and economical sizing of flow-line insulation materials. One of the industry requirements of the oil and gas production flow-line is to ensure the flow-line meets a discharge or an output temperature. This paper focuses on choosing and sizing of an insulation material to meet an output temperature of an oil and gas surface production flow-line. Two well stream flows were developed based on stream compositions from the two oil and gas wells. It is desirable that the discharge or output temperature of the discharge fluid at the discharge end of the flow-line does not fall below 20 degree Celsius. The thermal insulation thickness for the 1 km long production flow-line was designed using Urethane Foam insulation material. The chemical processes were modelled in Aspen Hysys and a case study was developed between flow-line output temperature and the flow-line insulation thickness to correlate the two variables.