Types of liquid pipelines transportation in batches: allows multiple products to be shipped in the same pipeline. it includes batch transportation of low as well as high vapor pressure fluids.

batches of different crude, grades, and products are pumped back to back in the line most often without any separating device
Typical products commonly transported as a single or batched products:
crudes:

heavy to extra heavy, medium heavy, and light heavy

intermediate

light

synthetic

Diesel:

low sulfur

ultra low sulfur

low pour

Gasoline:

leaded

unleaded

super

jet fuels

Distillate and Kerosene :

jet kerosene

jet naphtha

iso-octane

alkylate

condensate

propane

butane

Batched Product Pipeline Growth and Technique

batch interface: the region where two batches abut in a pipeline and some mixing of the products occurs
density affects the differential pressure as well as pressure due to elevation head
Viscosity major cause of friction losses in pipeline operations.

definitions and terms:
Batch: means by which product movements can be tracked, each batch must meet the clients specifications
Fungible Batches: a batch of petroleum product meeting carrier's established specification, which is commingled with or delivered in substitution for other quantities of petroleum product meeting the same specification.
Segregated Batches: a batch of petroleum product meeting carrier's established specifications which may not be commingled with out quantities

Batch Sequencing:
factors that affect the order of batches include:

compatibility with adjacent batches

batch cycle requirements

ratability

transmix or contamination levels

capacity and power availability and scheduling and operational requirements

product availability

buffering requirements

Batch Cycle/Slug
batch cycle: a set pattern of batches of similar commodity type that takes into account:

interface contamination of batches

injection and delivery patterns of batches

repeated usage for production of batch sequences

incompatible batch cycles are buffered to minimize contamination.
Buffer: petroleum commodity that physically separates dissimilar or different commodity types so as to minimize contamination. they sometimes create an insulating layer between heavy and light crude so that light components don’t migrate into heavy components and affect their vapor pressure and their flash point.

a cycle is a defined period where a prescribed set of products is transported in a particular order and in particular batch sizes

Slug/batch train : continuous stream of a single homogenous product within a pipeline. they're operational movement tools and are defined for the convenience of the scheduler.

Batching travel time:

time it takes for a batch to travel depends on:

flow rate

number and type of preceding

sequential batches

compressibility

differences between batches

pipeline elevation

Batch Interface Marking and Detection:

interface detection is necessary to send the incoming batch to the proper tank

they can be detected by a densitometer if they have significantly different densities

a fluorescent dye can be used to mark refined products batch interfaces and fluorometers are used to detect arrival of batch interfaces

optical interface detectors can also be used

a viscometer can be used to differentiate between the same product coming from two different points. a slight difference in viscosity will be present.

detectors are usually installed upstream of the delivery location

Calculating batch interface positions requires:

pipeline system configuration

current storage levels

injection/receipt and delivery volumes

batch sequences

Batch Injection, Transportation and Delivery

full stream Injections: fixed portion of the main line is completely filled with the fluid displacing its current content.

midline breakout tankage facilities :

help schedule start and end times for deliveries and injection

manages differing flow rates in pipeline segments of differing diameters

In side stream Injections:

the liquid pumping into the mainline shares the line with the same type of liquid already flowing in the line

this is useful when:

the allowable flow rate downstream is higher than that required by the upstream

the maximum injection flow rate at a supply terminal is lower than the required pipeline flow rate

this method offers the lsat impact on overall pipeline flow rates

Side Stream Delivery Operations: allow the pipeline to be used more efficiently by increasing capacity

they are good to use when:

the upstream allowable flow rate is higher than the downstream flow rate
the delivery rate at a terminal or location is low

Batch Reports are used for:

Assisting control center operators in operating the pipeline
help pipeline schedulers to schedule and coordinate batch movement
help maintenance staff schedule pipeline maintenance
indicator of pipeline capability/integrity

Minimum Batch Size:

determined by knowing the allowable contamination of one product in another

Interface volume Estimations:

method for estimating interface length and volume

step 1: blended viscosity can be determined

step 2: reynolds number for blended product

step 3 critical reynolds number is found

step 4: the interface length can then be calculated Lecture 4C, Slide 17

	Creado por Yasmina Moussa hace alrededor de 9 años

Normal-level (N-level) Transmission and Storage Apunte sobre Liquid Batching Transportation , creado por Yasmina Moussa el 28/10/2015.