Liquid Batching Transportation

Liquid Batching Transportation

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 deviceTypical 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 quantitiesBatch 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/Slugbatch 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 sizesSlug/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