changes in temperature affect liquid density and viscosity and affect pressure profile
if liquid transported near ambient conditions--> isothermal assumption in calculations
liquids in pipeline classified according to temperature behaviour into light, intermediate and heavy HCs
light and heavy dealt with non isothermally
intermediate HCs not as sensitive to changes in temperature in terms of density and viscosity
frictional heating negligibly small
isothermal flow assumption is reasonable if adequate average temperature is calculated
design considerations should include vapour pressure because that depends on temperature
pipeline network composed of: injection points - delivery point- intermediate station - pump stations - block valve stations - regulating stations
injection points: products injected into line
delivery point: where product will be delivered to consumer or another pipeline
intermediate stations: provide side stream injections or delivery points
pump stations: located along line to move liquid through pipeline
block valve stations: first line of mitigation for pipelines. enables operator to isolate segments of line
regulating stations: special type of valve station where either pressure or flow is controlled
pressure regulators usually located downhill of a peak
flow regulators installed at delivery stations
Pipeline configurations:
1. side stream delivery
2. side stream injection
3. pipelines in series
4. pipelines in parallel
modes of side stream delivery : strip delivery - full stream delivery through branch line - full stream delivery through mainline
design considerations for side stream delivery:
1. satisfy delivery pressure requirements at both delivery locations while maintaining high P at take off point
2. using a smaller diameter downstream if delivery volume is large ( increase in Q)
3. installing an extra facility such as pump to satisfy branch line delivery requirement
4. select pumps to meet max and min flow requirements
Side stream injection: liquid may be injected from branch lines into the main pipeline
Q is lower upstream from injection, so pressure drop upstream is lower than downstream
block valve installed upstream and closed in full stream injection or batching
injection pressure on the branch line should be higher than main line pressure to prevent back flow
larger diameter used downstream to handle large volumes from injection
pumps upstream to injection should be designed to accommodate reduced flow rate. flow rate downstream of injection will be high so flow rate needs to be reduced upstream
viscosity of injection fluid is high, high pressure drop, pumps downstream need to be designed accordingly
pipelines in series when different flow rates are transported or different pressures are required
in series--> same flow rate but different velocities
different sizes connected in series for change in flow or change in elevation
larger diameter --> slower velocity-->smaller friction factor--> lower pressure loss
different pipe wall thickness in series to reduce pipe material and cost while maintaining safety
thinner wall--> suction side
thicker wall--> discharge side
pipelines in parallel: arranged in parallel to reduce excessive pressure drop in a certain sections of the pipeline and increase throughput in bottleneck
pressure remains the same in parallel, but Q is the sum of flow rates in
size of parallel pipelines can be different and so will the velocity be
equations governing flow in parallel pipes slide 24

	Created by nada.h.aly about 9 years ago

Normal-level (N-level) Oil & Gas Transmission & Storage Note on 3C - Crude Oil Pipeline Systems & Pipeline Configurations, created by nada.h.aly on 28/10/2015.