oil pipeline logistics - cepaccepac.cheme.cmu.edu/pasi2008/slides/cerda/library/slides/jcerda... ·...

1

OIL PIPELINE LOGISTICS

Jaime Cerdá

Instituto de Desarrollo Tecnológico para la Industria Química Universidad Nacional de Litoral - CONICETGüemes 3450 - 3000 Santa Fe - Argentina

Pan American Study Institute on Emerging Trends in Process Systems EngineeringAugust 11-21 , Mar del Plata, Argentina

2

Motivation

The multiproduct pipeline planning problem

Available pipeline planning approaches

Presentation of a continuous planning approach

Critical operational decisions & major problem constraints

An illustrative example

Static vs dynamic planning problem

The detailed weekly pipeline schedule

Conclusions

OUTLINE

3

ACKNOWLEGMENT

The material included in this presentation

have been extracted from

DIEGO C. CAFARO’s Doctoral Thesis

currently in preparation

4

Most reliable, safest and cheapest way of delivering large volumes of a wide range of refined products from refineries to distant depots.

Batches of different grades and products are pumped back-to-back in the line without any separating device.

Batches move forward in the line and products are transferred to terminals whenever a new batch is injected at the head terminal.

LIQUID PIPELINE OVERVIEW

Segment Segment

Distribution Terminals

D2D1 D4D3 D5

Interfaces

Head Terminal

RefineryP4P3P1P2

5

PIPELINE MAJOR FEATURES

Usually buried and invisible to the public

With several intermediate entry and exit points

With segments of varying diameter

Large diameter pipelines due to high construction costs

With crude oil and refined products moving in separate lines

Always remaining full of liquid and pumping in only one direction.

Trans Alaska Pipeline

System

Colonial PipelineREFINERIES

COLONIAL

6

PIPELINE OWNERSHIP – REMOTE OPERATION

Owned by a large number of companies, almost all are common carriers

An increasing number are owned by non-oil companies

Operations are fully automated and remotely performed

From centrally located control rooms, operators direct the product flow

From there, they start & stop pumps, open & close valves, fill & empty tanks

Supervisory control & data acquisition systems, known as SCADA, are used

SCADA continuously monitors: pump pressures flow ratesbatch locations tank levels

7

PIPELINE ADVANTAGES

Operate around the clock all seasons and under all weather conditions

No container moves with the cargo. Products only move.

No backhauls

Employment is only 1% of that of the trucking industry

Very low transport damage to products and especially to the environment.

THE CHEAPEST MODE OF TRANSPORTATION

Lines coated with corrosion-resistant chemicals to prevent corrosion

Chance of leaks reduced by an extensive maintenance program

“Smart pigs” sent through the line - detect dents and imperfections - measure wall thickness

Scraper PIGS

THE SAFEST MODE

“Scraper pigs” clean the inside of a line byremoving residual material clinging to the walls

BUT THE SLOWEST MODE(3 TO 8 MPH)

8

INTERMODAL PRODUCT MOVEMENTS

Pipelines dominate the oil industry transportation

Participate in intermodal product movementswith other modes of transportation

- tankers & pipeline combination for crude oil

- pipeline/truck combination for refined products

A batch in the line arriving at a terminal:- can be placed in a tank - can be rerouted into another pipeline

Lines provide tanks to buffer theflow rates between two connectingpipelines or line segments of different diameters

REFINERIES

DISTRIBUTION TERMINALSOIL FIELDS

CLIENTSCRUDE

OILIMPORTS

PIPELINES

0

10

20

30

40

50

60

70

80

1980 1985 1990 1995 2000 2005

Pipelines (%)

Vessels (%)

Trucks (%)

Trains (%)

CRUDE OIL DOMESTIC TRANSPORT MARKETIN USA

PIPELINES

VESSELS

9

MONITORING BATCH STATUS

The specific gravity of the flow is continuously monitored at every terminal

When it changes, the operator knows that:- one product batch is ending- another product batch is beginning to arrive

Refined products are often “color-coded” with dye

The operator can visually observe the transition

Distribution Centers

D2D1 D4D3 D5

Interfaces

Head Terminal

RefineryP4P3P1P2

10

POWER CONSUMPTION

The power consumption is the largest pipeline operating cost.

Liquid products are propelled by centrifugal pumps sited at the pumpingstations one at the origin and the others distributed along the line.

The capacity of a pipeline can be increased by installing additional pumpingstations along the line to rise pressure.

11

INTERFACE MATERIAL

Pipelines move different grades of a product or distinct products sequentially through the same line in “batches”.

At the boundary of two consecutive batches some mixing occurs.

Between batches of different grades

Interface Mixed with the lower grade product

PRODUCT DEGRADATION

Between batches of different products

Transmix Separated and sent back to the refinery

TRANSMIX REPROCESSING

12

INTERFACE COSTS

Product degradation and transmix reprocessing costs both significantly contributeto the pipeline operating cost.

Amount of Interface

Number of batches

Arrangement of batches in the line

CRITICAL DECISIONS

Batching Operations

Keep similar products fromdifferent refiners togetherInject the lowest possiblenumber of product batches

Sequence batches by specific gravities

Batching Sequencing

Some products are prohibited to be consecutively injected to avoid a serious product degradation.

Batch sequencing is also important to meet product delivery due dates at terminals

13

PIPELINE OPERATING MODES

More stringent environmental regulations on car fuels have resulted in aproliferation of refined products.

Major refined product pipelines currently move 100-120 distinct productscompared with 10-20 in the ‘60s.

OPERATING MODES

BATCH MODE FUNGIBLE MODE

the same volume accepted for shipment to a particular depot is the

one delivered to that destination

standard refined products from different refiners are

consolidated into a single batch

LARGER NUMBER OF BATCHESHIGHER INTERFACE COSTS

SMALLER NUMBER OF BATCHESLOWER INTERFACE COSTS

14

T iem po[sem ana s]0 1 2 3 4

P 1P 1P 2 P 3 P 1P 1P 2 P 3 P 1P 1P 2 P 3 P 1P 1P 2 P 3

T iem po de C ic lo (T C )

[d ías]

N o . deB a tches

7 16

P 1P 1P 2 P 3 P 1P 1P 2 P 3 14 8

P 1P 1P 2 P 3 28 4

T C = 28

TC = 14T C = 7

N ive l de In ven ta rio de P rodu cto P 2 en e l D estino , según e l

T iem po de C ic lo (T C )

T ie m p o

T ie m p o de T ra n sp orte

PIPELINE BATCHING OPERATIONS

Numberof batches

16

8

4

THREE PRODUCTS : P1, P2 , P3SELECTED BATCH SEQUENCE: P1 – P3 – P1 – P2THE SAME AMOUNT OF PRODUCTS SHIPPED TO TERMINALSTIME HORIZON: 4 WEEKS

Period Length

7

14

28

weeks time

days

SHORTER PERIOD LENGTH – SAME BATCH SEQUENCE IN EACH PERIOD

LARGER NUMBER OF BATCHES AND INTERFACE COSTSSMALLER BATCHES AND LOWER TERMINAL TANK CAPACITIES

4-PERIOD HORIZON

2-PERIOD HORIZON

ONE-PERIOD HORIZON

Inventory Level of P2 at the Depot

Transportation Time

time

15

B1B2B3

D1 D2REF

B4

D1REF

D2

B4

D1 D2REF

B4

D1 D2REF

B4

D1 D2REF

B4

D1 D2REF

D1 D2REF

B1B2B3B4B5

D1 D2REF

B5

D1 D2REF

B5

D1 D2REF

STRIPPING OPERATIONS (“CUTS”)

Every new batch injection pushes some batches forward while others that arrive at their destinations are partially or completely sent out of the line (“stripping operations”) and loaded in the terminal tank.

Therefore, both the size and the location of every batch in the line can changeduring the pumping of a new batch.

Batch stripping takes place if the batch has arrived at the terminal and enoughstorage capacity to receive the material is available.

Otherwise, the line should be temporarily stopped and deliveries are interrupted.

D1 D2REF

B5 B1B2B3B4

http://www.pipeline101.org/Operating/batching_model.html

16

A fungible batch with multiple destinations will undergo several stripping operations(“cuts”) along the journey.

A batch can travel to the farthest destination for 7-14 days (“delivery lead-time”).

A fungible batch may satisfy several product requirements at different terminals,i.e. multiple destinations.

Every product delivery has its own due date.

BATCH DUE DATES & DELIVERY LEAD-TIME

Fungible batchMultiple destinations

Multiple due dates

Delivery lead-time Is a function ofDepot locationPumping ratePipeline idle time

Most short-term product requirements are satisfied by batches currently in transit.

17

A common carrier pipeline terminal typically connects to the marketing terminals of its main shippers or to public storage terminals.

Gasoline tank trucks are loaded from storage tanks at marketing terminals

Terminals have few tanks just to facilitate stripping operations and quality control tasks.

In fungible mode, a fewer number of larger storage tanks is usually needed.

Tanks for long-term storage must be provided by the customer at entry & exit points.

LOADING & UNLOADING OPERATIONS

Trunk Line

Marketing Terminal

Pipeline Terminal

18

A cyclic schedule is usually performed.

Customers should make the product timely available at the input terminal and provide enough storage capacity at its destinations.

US pipelines are mostly COMMON CARRIERS, i.e. services are provided to multiple oil refiners.

Customers contact the pipeline operator to place their shipment orders for the next month, called NOMINATIONS.

The monthly planning horizon is composed by a number of periods, called CYCLES.

A NOMINATION specifies the product and the quantity to be shipped.

SHIPPER NOMINATIONS

Every nomination is divided into a number of equal-size batches, one for each cycle.

19

Operational decisions concerning to every batch to be injected include:

- the assigned destinations (terminals)

- the amount allocated to each destination (the cut sizing)

THE PIPELINE SCHEDULING TASK

Planning pipeline operation in fungible mode implies to choose:

- the set of batches of each product to be injected, and the batch sizing

- the sequence of batch injections

- batch injection rates and starting times

Operational decisions related to each batch pumping run include:

- the set of “stripping operations” to be carried out

in-transit batches to be stripped out - receiving depots - cut sizes

- the location & size of every in-transit batch at the end of a batch injection

20

BATCH INJECTION & STRIPPING OPERATIONS

DepotD1

Depot D2

DepotD3

C5-L5 _ C5 150

50

30

50

20

At time C4

At time C5

200 190 180 200

150 150 160 130

180

B1B2B3B4

B5 B4 B3 B2 B1

P4P3P2

P1

CURRENT PIPELINESTATE

NEW BATCH INJECTION

NEW BATCH B5

STRIPPING OPERATIONS

REFINERY

STRIPPED BATCHESB4 – B3 – B2 – B1

21

PIPELINE SCHEDULING GOALS

To minimize operating costs including:

- the transmix reprocessing cost & the product degradation cost

- the pumping cost

- the inventory costs in refinery and depot storage tanks

To keep the pipeline running at nearly maximum capacity during off- peak hours

To enhance the information on the current status of batch movements

To meet product delivery requests on time

22

The sequence of “old” batches already inside the pipeline.

The scheduled production runs at the refinery.

The inventory levels in refinery and terminal tankage at the initial time.

The set of shipment requests, each one involving a refined product, the assigned terminals and the delivery due dates.

PROBLEM DATA

Their locations & volumes at the initial time of the planning horizon.

23

Knowledge-based Search Techniques (Sasikumar et al., 1997)

Cyclic Scheduling Techniques (Used by pipeline schedulers)

Mixed-Integer Mathematical Programming Formulations

- Discrete Formulations (Rejowski & Pinto, 2003)

- Continuous Formulations (Cafaro & Cerdá, 2004 & 2008; Relvas et al., 2007)

PIPELINE SCHEDULING APPROACHES

Metaheuristic Search Algorithms- Greedy algorithms (Hane & Rattliff, 1995) - Genetic algorithms (Nguyen & Chan, 2006)- Tabu search (García et al., 2008)

Discrete Event Simulation (Maruyama Mori et al., 2007)

24

Discrete Formulations (Rejowski & Pinto, 2003)

MIP DISCRETE FORMULATIONS

Pack 1 Pack 2 Pack 3 Pack 4

t = T1

T2

T3

P1P1P1 P2

P1P2P1 P1

P2P1P1 P1...

The pipeline is divided into packs of uniform size at each segment

Each pack contains exactly one product

The time scale is divided into slots of fixed length (fixed pumping rate)

Whenever a pack of product enters a segment, the content of the firstpack in that segment is displaced to the next pack.

Very large MILP formulations for longer planning horizons

25

MAJOR FEATURES

MILP CONTINUOUS APPROACH

A “cheap” generalization to pipelines with several intermediate input andexit points

Delivery due dates at the end of every planning period

Explicit treatment of interface volumes

Multiperiod planning horizon

Pre-defined ordered sequence of empty batch slots of variable-size

Continuous time & volume representation

26

MAJOR DECISION VARIABLES

Allocation variables assigning products to “empty” batch slots

MILP CONTINUOUS APPROACH

Stripping operations to take place during a batch injection (batch to be stripped, cut size, receiving terminal)

Location and size of in-transit batches at the end of a new batch injection

Starting and completion times of new batch injections (the time events)

Assignment variables denoting the planning period at which a batch injection ends

Control variables indicating the arrival of a batch at the assigned terminal to start the stripping operation

MAJOR CONTINUOUS VARIABLES

Initial sizes of batches to inject in the pipeline

Inventory levels at refineries and pipeline terminal tanks at every time event

27

The size of the interface between consecutive batches depends on the assigned products

B1B2

P3P1

IFP1,P3

flow

WIFB2,P1,P3 =

new

Pppi Iiy ∈∀≤∑

∈1,

A single product can at most be assigned to a batch slot

PppiIiyyIFWIF pipippppi ∈>∈∀−+≥ − ´,1,)1(* ,',1',',,

MAJOR MODEL CONSTRAINTS

A new batch injection can be started after completing the previous one

PppIiyyCLC newpipippiii ∈∈∀−++≥− −− ´,;)1(* ,',1´,1 τ new

maxii IihCL ∈∀≤≤

28

The length of a pumping run depends on the batch size & the pumping rate


The size of a flowing batch changes during a batch injection due to theexecution of stripping operations

newiii IiLvbQLvb ∈∀≤≤ ** maxmin

At time C4200

Depot D1

C5-L5 _ C5 100

At time C5

260

100 (B5)

100

160 (B4)

DB4,D1 (B5)

= 40 200

i'i,I'i,IiDWW new

Jj

)'i(j,i

)1'i(i

)'i(i >∈∀∈∀−= ∑

∈

−

200 – 40 = 160

29

The overall amount of products delivered to terminals through strippingoperations is equal to the size of the new batch injected in the line


Depot D1

Depot D2

Depot D3

C5-L5 _ C5

150

50

30

50

20

At time C4

At time C5

200

190 180 200

150

150 160 130

180

B1B2 B3B4

B5 B4 B3 B2 B1

150 (in) = 50 + 30 + 50 + 20 (out)

A single time period will contain the completion time of a pumping run

0 h

wB1,T1 = 1

35 h

65 h

0 h

T1 T2 T3 T4

48 h 72 h 96 h 144 h

wB2,T2 = 1 wB3,T3 = 1 wB4,T4 = 1

23 h B1 B2 B3 B4

70 h 93 h 102 h 125 h

TIME PERIODS

BATCH INJECTIONS

30

Feasibility conditions for stripping operations- An upper bound on the cut size- The flowing batch has reached or will reach the depot during the pumping run


At time C5300100

Depot D1

160

50reserved

for D1

Depot D2

350

100

50 already gone

200available for D2

B3B4B5

290100 10010

10

10

240 100 100 50

60

50

50 100 100 190

250

190

At time C6

B3B4B5B6

B3B4B5B6

B5B6 B4 B3

CONSECUTIVE STRIPPING OPERATIONSDURING INJECTION OF B6

CUT 1

CUT 2

CUT 3

CURRENT PIPELINE STATE

31

Delivery time constraints

THE OBJECTIVE FUNCTION

∑ ∑∑ ∑

∑

∑ ∑ ∑∑∑

∑ ∑ ∑ ∑

∈ ∈∈ ∈

∈

∈ ∈ ∈>∈

≠∈

∈ ∈ ∈ ∈

⎥⎦

⎤⎢⎣

⎡⎟⎠

⎞⎜⎝

⎛+⎟

⎠

⎞⎜⎝

⎛+

⎟⎠

⎞⎜⎝

⎛−−+

++

+⎟⎠

⎞⎜⎝

⎛=

Pp Inewi

ipp

Jpj Inewi

ijpjpnew

Inewii

Pp Jj Tttjp

tjp

iIi

ppipp

ppPp

Pp Jj Ii Inewi

ijipjp

IRScirIDcidIcard

LPHhcu

BcbWIFcf

HDPcpzMin

'

)'(

'

)'(,,

maxmax

,,)(

,

1

',,',

''

'

)'(,,,

**)(

1

*

* ρ

Minimize pumping cost, interface reprocessing cost, pipeline idle time and inventory carrying cost

OBJECTIVE FUNCTION

Batch injections completed up to period t are available to meet product requirementsto be delivered to terminals before the end of period t

newp

tjptjptiti

t

kkjp

i

I

jp

IiTtJjPp

BBwwdemDMnew

∈∈∈∈∀

+−⎟⎠

⎞⎜⎝

⎛−≥ −+

=∈=

∑∑

,,,

)(* )1(,,,,,1,1

,,1

)(,

ll

l

32

A pipeline system with a single entry point and multiple exit points (5 terminals)

A REAL-WORLD PIPELINE PLANNING EXAMPLE

PROBLEM DATA

Unidirectional flow

Four different products (gasoline, diesel, LPG, jet fuel) are sent to terminals

Time horizon length: 4 weekly periods (672 h)

Pipeline Length: 955 km

Variable Segment Diameter: 12 – 20 in

Pump rate range: 800 – 1200 m3 per hour

33

OPTIMAL STATIC PLANNING

R

Run Time Interval

[h]

Volume [102 m3]P4P3P1 P2

D2 D1 D4 D3 D5

120

70

1180

400.37

320.37

962.5

679.63

134.63

1220

672.5

555

425

415

400

400

700

550

200

190

200

70

135

0 200 400 600 800 1000 1200 1400 1600

0

5.00_52.00

55.00_198.33

202.33_309.21

358.28_412.07

524.50_672.00

425

1720

90

60

80

10

135 50

310

190

410

140

247.

5

70

152.

5 10

INITIAL STATE

INJECTING P4

INJECTING P2

INJECTING P1

INJECTING P3

INJECTING P1A VERY LARGE BATCH

STRIPPING OPERATIONS

ASSUMING A FIXED PLANNING HORIZON

THE HORIZON-TIMEEFFECT

FIVE BATCH INJECTIONS

IDLE TIME

34

As time goes on, new transport requests are received and others are cancelled

Periodical planning update permits to eliminate the horizon-end time effect and, more important, the pipeline idle time

DYNAMIC PIPELINE PLANNING TASK

The current pipeline schedule should be periodically updated at the start of anew period

A sufficiently long rolling time horizon should be considered

The horizon-time effect arises because later batch injections have the onlypurpose of pushing batches to their destinations

As the planning horizon rolls, such later batches will be injected because of newreal shipment requests

35

DYNAMIC PIPE PLANNING ALGORITHM

y

n

Refinery Production Schedule

Planned Pipe Schedule for

periods k+hf to k+N-1

Definite Pipe Sequence for periods k+hf to k+hf+sf-1

Initialization Stage

Data Updating

Stage

Trigger Stage

ReschedulingStage

Dispatching Stage

Definite Pipe Schedule for

periods k to k+hf-1

OUTPUTS

INPUTS

SCADA Remote Pipeline Controlling

System

clock = ddk-1 ?

- Capture pipeline batch scenario (products, volumes and locations) (Iold

p, Woi, Fo

i)

- Capture product inventories at refinery and depot tank farms (IRo

p, IDop,j)

Updating the Pipeline Schedule Run the Multiproduct Pipeline Scheduling Optimization System(MPSOS) for the planning horizon including periods k to k+N-1

- Execute the Pipeline Schedule for the time horizon going from ddk -1to dd(k+hf-1) (periods k to k+hf-1)

- Set k = k+tRS

Demand Updating Process

Update Product Demand Data forperiods k to k+N-1

- Import updated refinery production schedule and product output rates for periods k to k+N-1 (time horizon [ddk-1 ; dd(k+N-1)])

- Set h (time period length) [hours] - Set N (number of time periods to be considered) - Set sf = ⎜TSF ⎜ (soft-frozen time periods) - Set hf = ⎜THF ⎜ (hard-frozen time periods) - Set k = 1. ddk-1 = 0. - Set clock = 0 [h]. Run clock

36

OPTIMAL DYNAMIC PIPELINE PLANNING

INITIAL STATE

ASSUMING A 4-WEEK ROLLING PLANNING HORIZON TEN BATCH INJECTIONS

Run Time Interval

[h]

Volume [102 m3]P4P3P1 P2

D2 D1 D4 D3 D5R

0 200 400 600 800 1000 1200 1400 1600

400 700 200 200 1350

120 70

1220

425

415

400 550 190 705.00_52.00

55.00_168.00

425

1356

90

60

80

10

135 50

136

410

140

247.5

70

152.5

10

120 1220 295 173.00_183.00

120

120

924.63 120 547.5 42.87184.00_286.89

90

180

100

245

120

160

247.5

92.13

1234.63

659.78

390 647.72 120 477.28

327.5

259.62 507.66

280

280

247.72

247.72

120

220

338.00_384.00

385.50_440.95

441.95_463.58

466.58_504.00

276.9

1

42.87

70.22

110

5.59

400

149.7

8 390

665.37

44.41

107.7

1

259.62 120

107.5

449.04 259.62

90

40

105.3

8

449.04 402.28 190 247.72

213.6

6

80 6.34

290.38

1446.34

1155.96

9.62

9.6249.04

49.04

130

130504.00_630.25

635.25_659.44

400

3.62

65

120

350

129

.62

6.34

80

247.7

2 70

42

.66 1513.96

290.38

36.38

254

SHORT IDLE TIME

37

Pipeline Usage

Refinery Inventory Profiles

0

500

1000

1500

2000

2500

0 168 336 504 672Time [h]

Inve

ntor

y Le

vel [

m3 ]

P1 P2 P3 P4

0 168 336 504 672

P4P3P1 P2 Changeover Idle time Time [h]

Qi[102 m3]

425 1356 120 1235 390 665 260 1963 290

ADDITIONAL RESULTS

38

Multiple-source pipelines include additional input terminals at non-origin pointsto collect oil product batches from downstream refineries

So far, we deal with single-source multiple-destination trunk pipelines

B1B2B4B6 B3

s1 s2j1 j2 j3

B1B2B4B6 Al final de K1 B3

xsB3,s2(K1) = 1

xdB2,j2(K1) = xdB1,j2

(K1) = 1 xdB1,j3(K1) = 1

B5

B5

P1 P2 P3 P4

MULTIPLE-SOURCE TRUNK PIPELINES

INTERMEDIATE INPUT TERMINAL

B3

Need of choosing the input terminal where the next pumping run will occur

At intermediate input terminals, a new batch can be injected or the size of a flowing batch can be increased

INJECTION OF BATCH B3

39

In multiple-source trunk pipelines, batches are not sequenced in the same orderthat they were injected in the line

B1B2B4B6 B3

s1 s2j1 j2 j3

B1B2B4B6 Al final de K1 B3

xsB3,s2(K1) = 1

xdB2,j2(K1) = xdB1,j2

(K1) = 1 xdB1,j3(K1) = 1

B5

B5

P1 P2 P3 P4

MULTIPLE-SOURCE TRUNK PIPELINES

INTERMEDIATE INPUT TERMINAL

B3

A batch is not necessarily preceded by those previously pumped in the line

Batch B4 is preceded by batch B3 even though B4 was inserted before

Need of separately handling the pumping run sequence and the batchsequence

40

At the very operational level, a detailed pipeline schedule for the action period

of the current horizon must be prepared

The basic information is provided by the monthly pipeline planning

DETAILED PIPELINE SCHEDULE

Just the batch injections and stripping operations planned for the first period ofthe current time horizon are to be performed

A more detailed definition of the stripping operations to execute during a batchinjection is required: sequence, timing and extent of stripping operations

Additional systematic heuristic/algorithmic procedures providing a detailed

description of the required stripping operations are to be applied

41


Nearest Active Depot First (NDF) rule:

Run Time Interval

[h]

D2 D1 D4 D3 D5R

400 700 200 200 1350

300

200

5.00_70.00

150

MDS

Q dd[h] N2 100 18 N3 200 72

Nominations

Q dd[h] N1 200 48

Nominations Q dd[h] N4 150 12

Nominations

DPS

200 400 200 50 135650

400 650 900 1500 1635Volume [102 m3]

Mean Flow Rate = 10.00 0 650

D2 D1 D4 D3 D5

Run Time Interval

[h]

R

400 700 200 200 1350

200 1355.00_15.00

150

100

135

100

15.00_30.00

200 135

200

450

200 400 135

150

500

400

250 400

600

450

30.00_50.00

50.00_55.00

Volume [102 m3]

Flow Rates

=

Mean Flow Rate 100

150

200

50

200 400 200 50 135650

0 400 650 900 1500 1635

55.00_70.00 150

50

200

200 200

450 200 200

200 200

In which order the “strippingoperations” should be executed during a batch injection?

PRIORITIZE DELIVERIES

TO THE NEAREST DEPOT

AT THE PLANNING LEVEL

AT THE OPERATIONAL

LEVEL

42


MILP Formulation:

Run Time Interval

[h]

D2 D1 D4 D3 D5R

400 700 200 200 1350

200 50 1355.00_18.00

150

150

200 50 135

100

18.00_30.50

200 200 50 135

200

450

200 400 200 50 135

200

650

400 700

250 400 600

600

0 400 650 900 1500 1635

30.50_48.00

48.00_70.00

Volume [102 m3]

Flow Rates

11.53

8.00

11.42

9.09

150

100

200

200

Comparative Results:

Rule Valve operations Earliness [h] Tardiness [h]NDF 5 39 43 FDF 4 22 4 EDD 4 2 2 MILP 4 2 0

NEAREST DEPOT

FARTHEST DEPOTEARLIEST DUE DATE

43

B1B2B3

B4B5

Refinery 1 Refinery 2

Depot 1 Depot 2 Depot 3

Batch B3 will be pumped in Refinery 2

30 70 40Supply

30 5030Demand 30

A MULTIPLE-SOURCE PIPELINE SCHEDULE

Horizon Length: 120 hs.

44

Inject Product P1 (Batch B5) in Refinery 1

Deliver Product P1 (Batch B5) to Depot 1

B1B2B3

B4B5


45



B1B2B3

B4B6


46



B1B2B3

B4B6


47



Refinery 2 is ready to inject Product P3 in Batch B3

B1B3B4B6


48



B1B3B4B6


49



B1B4B6


50



B4B6B8

Note that Batch B7 has been preserved to be injected in

Refinery 2

B7


51

Deliver Product P2 (Batches B4 & B6) to Depot 3


B6B8B9B7


52


B6B8B9 B7


Refinery 2 is ready to inject Product P3 in Batch B7


53

A continuous pipeline planning approach has been presented

Multiproduct pipeline planning is a very complex industrial problem

The approach can even be applied to multi-source multiproduct pipelines

CONCLUSIONS

Tools for generating a weekly detailed pipeline schedule have alsobeen briefly described

Pipeline planning over a multiperiod rolling horizon with delivery due dates at period ends is performed

The approach still remains competitive for a monthly time horizon

54

OIL PIPELINE LOGISTICS

Jaime CerdáInstituto de Desarrollo Tecnológico para la Industria Química

Universidad Nacional de Litoral - CONICETGüemes 3450 - 3000 Santa Fe - Argentina

Thanks for your attention!Questions?

Contact: [email protected]

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