Pipeline Operations:

Business

Physical

Physical: covers the product movements and pipe cleaning or pigging and integrity management
Products are gathered in central points and then dispatched to various destinations.
--> this is done through scheduling which involves product pumping schedule that is based on:

pipeline capacity

shippers requirements

Controlling of pipeline pressure is important it sets certain operating limits:

MAOP

Maximum discharge pressure to protect piping & equipment

Minimum suction pressure to avoid cavitation

Max/Min pressure at a control point

Max/Min delivery pressure for contractual obligations

Min/Max flows through pumps for efficient pump operation

Maximum power of pumps

Minimum discharge temperature for pipelines in permafrost

Booster Pumps are installed between the tanks and the pump station because tanks don't provide sufficient suction head

Tight Line Operations --> when there are multiple intermediate pump stations and open station pumps directly into the suction side of the pumps at the next station.
the advantages over the previous operation:

tanks are not necessary at the mainline stations

extra operation of pumping into and out of tankage is not required

interfacial mixing is minimized for batch operation

Pressure monitoring and controlling points:

suction set point: suction pressure limits, a lower limit under which the pump will not operate and shut down. An Upper limit needs to be reduced to avoid over pressuring the discharge pressure at the upstream station.

discharge set point: this pressure is to be maintained as a maximum pressure. if pressure is equal to or higher than the discharge set point the pressure regulator is activated to reduce the actual pressure level.

tight line operation--> liquid density and viscosity changes can occur in batching or blending operation
if stations have centrifugal pumps are operating at maximum pressure the flow will decrease and the density and viscosity increase
Sphere:
form of pig that is put in place to separate the two adjacent products.
it can be inserted at the injection point or the running pump stations and received at the delivery point or at running pump stations further along the pipeline
without the pig, interfacial mixing or transmit takes place

this depends on the pipe length and reynolds number

There are rules that outline the handling of transmix:

interface mixture maybe cut into one or the other product, or divided between two adjacent products

Slop--> when the transmix doesn't meet the shippers specifications

if the size of transmix is larger than the specified amount and cannot be blended into other products the company must pay

Batching tracking

monitors the volume of each batch, its origin and its destination, current location and ETA

its tracking begins when the batch is launched and tracked using difference in density or value status or on batch schedule

volumes are updated based on injection and delivery volumes obtained at metering locations

Batch interfaces can be detected by a densitometer or by dye detector.

	Created by Yasmina Moussa about 9 years ago

Normal-level (N-level) Transmission and Storage Note on Pipeline System Operation , created by Yasmina Moussa on 28/10/2015.