Slugcatcher

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Slug Catcher is the name of a unit in the gas refinery or petroleum industry in which slugs at the outlet of pipelines are collected or caught. A slug is a large quantity of a liquid that exists in a multi-phase pipeline.

Contents

Slugs

Pipelines that transport both gas and liquids together, known as two-phase flow, can operate in a flow regime known as slugging flow or slug flow. Under the influence of gravity, liquids will tend to settle on the bottom of the pipeline, while the gases occupy the top section of the pipeline. Under certain operating conditions gas and liquid are not evenly distributed throughout the pipeline, but travel as large plugs with mostly liquids or mostly gases through the pipeline. These large plugs are called slugs.

Slugs exiting the pipeline can overload the gas/liquid handling capacity of the plant at the pipeline outlet, as they are often produced at a much larger rate than the equipment is designed for.

Slugs can be generated by different mechanisms in a pipeline:

Slugs formed by terrain slugging, hydrodynamic slugging or riser-based slugging are periodical in nature. Whether a slug is able to reach the outlet of the pipeline depends on the rate at which liquids are added to the slug at the front (i.e. in the direction of flow) and the rate at which liquids leave the slug at the back. Some slugs will grow as they travel the pipeline, while others are damped and disappear before reaching the outlet of the pipeline.

Purpose of the slug catcher

A slug catcher is a vessel with sufficient buffer volume to store the largest slugs expected from the upstream system. The slug catcher is located between the outlet of the pipeline and the processing equipment. The buffered liquids can be drained to the processing equipment at a much slower rate to prevent overloading the system. As slugs are a periodical phenomenon, the slug catcher should be emptied before the next slug arrives

Slug catchers can be used continuously or on-demand. A slug catcher permanently connected to the pipeline will buffer all production, including the slugs, before it is sent to the gas and liquid handling facilities. This is used for difficult to predict slugging behaviour found in terrain slugging, hydrodynamic slugging or riser-based slugging. Alternatively, the slug catcher can be bypassed in normal operation and be brought online when a slug is expected, usually during pigging operations. An advantage of this set-up is that inspection and maintenance on the slug catcher can be done without interrupting the normal operation.

Slug catcher types

Finger type slug catcher at the Qadirpur Gas Field Qadirpur Gas Field.jpg
Finger type slug catcher at the Qadirpur Gas Field

Slug catchers are designed in different forms,

Slug catcher locations

Finger type slug catchers are large in size and can be observed on satellite images. The following table is generated using Google Earth and gives an overview of slug catchers in the world. The slug catcher length is determined using measurement tool in Google Earth and is estimated to be +/- 5 meters accurate.

CountryNameRemarkBottlesLength [m]LatitudeLongitude
ARRio Cullen Slug Catcher4240-52.90317-68.35208
AUGorgon Slug Catcher 112205-20.78881115.44490
AUGorgon Slug Catcher 214110-20.78884115.44423
AUKarratha Slug Catcher 1Volume 5000m3?14345-20.58892116.77609
AUKarratha Slug Catcher 28225-20.58565116.77904
AUKarratha Slug Catcher 316315-20.61163116.76680
AUWheatstone Slug CatcherWheatstone LNG Gas plant24300-21.69308114.99779
AZSangachal Slug Catcher 1Shan Deniz 1 sub sea pipeline1213040.1890049.46417
AZSangachal Slug Catcher 2Shan Deniz 2 sub sea pipeline813040.1938049.47019
BNSlug Catcher 18704.66855114.45955
BNSlug Catcher 261354.66821114.46046
BNSlug Catcher 3181504.67457114.46744
CNZhuhai Gaolan Slug Catcher2816521.88548113.26463
DKSlug catcher Nybro411555.672128.36611
EGIdku Slug Catcher 11210331.3576930.32672
EGIdku Slug Catcher 2617031.3619830.33079
EGIdku Slug Catcher 3612531.3650830.33215
EGIdku Slug Catcher 4128831.3704130.32940
EGIdku Slug Catcher 51210331.3608230.32693
EGSlug Catcher 1411531.3415832.10563
EGSlug Catcher 2821531.3415232.10544
EGZohr Slug Catcher 1413031.3207132.14526
EGZohr Slug Catcher 2413031.3205532.14516
EGZohr Slug Catcher 3413031.3192432.14787
EGZohr Slug Catcher 4413031.3190932.14777
IEBellenaboy Bridge Slug Catcher9554.23347-9.74356
IEBellenaboy Bridge Slug Catcher9554.23347-9.74356
ILSharon Udasin Slug Catcher47031.8494534.67977
IRSlug CatcherGas pipeline to Turkey411039.3966544.39614
IRSlug Catcher 127.6914052.24349
IRSlug Catcher 227.6914052.24349
IRSlug Catcher 327.6885152.25925
IRSlug Catcher 427.6885152.25925
IRSlug Catcher 527.7165952.20021
IRSlug Catcher 627.7165952.20021
IRSlug Catcher 727.7265352.17832
IRSlug Catcher 827.7265352.17832
IRSlug Catcher 927.7265352.17832
ITSlug Catcher 144037.6673012.53984
ITSlug Catcher 244037.6673012.53984
ITSlug Catcher 344037.6673012.53984
LYSlug Catcher 132.8589112.24242
LYSlug Catcher 232.8589112.24242
MOTamane Slug Catcher-21.7470135.05903
MYBintulu Slug Catcher 13.28802113.07969
MYBintulu Slug Catcher 23.29392113.08913
MYBintulu Slug Catcher 33.29329113.08778
MYBintulu Slug Catcher 43.28757113.07892
MYKimanis Slug Catcher 182055.64175115.88684
MYKimanis Slug Catcher 282055.64100115.88684
NGBonny GTS-2/44.423267.15990
NGBonny NLNG GTS-14.424117.15917
NGBonny OGGS GTS-34.424057.16031
NGKwaleKwale AHL Gas plant5.725526.39195
NLHarlingen53.188615.43573
NLNAM52.920284.79385
NLNAM52.920284.79385
NOHammerfest Slug Catcher 189570.6840923.59074
NOHammerfest Slug Catcher 289570.6819923.58454
NONyhamna Slug Catcher 1Ormen Lange gas field1416062.848516.93893
NONyhamna Slug Catcher 2Ormen Lange gas field1416062.848056.94050
PEKinteroni Field Slug Catcher-11.83780-72.94533
PKDhodak Plant Slug Catcher30.8164270.48968
PKKunnar Slug Catcher 125.3836968.58074
PKKunnar Slug Catcher 225.3836968.58074
PKQadirpur Slug Catcher28.0547369.36721
QASlug Catcher 125.8896551.53810
QASlug Catcher 225.8877151.54215
QASlug Catcher 325.8864451.54472
TMSlug catcher Dragon OilDragon Oil611039.4011753.18819
TMSlug cather43338.5143254.21043
TMSlug catcher 1 PetronasPetronas Carigali GTPOGT812040.1678952.76912
TMSlug catcher 2 PetronasPetronas Carigali GTPOGT1023040.1631852.77123
TRBlue Stream Slug CatcherBlue stream413041.3598536.71042
UEHabshan 5 plant Slug Catcher23.9076653.71354
UEHabshan Slug Catcher 1GASCO Habsan plant23.8373453.65407
UEHabshan Slug Catcher 2GASCO Habsan plant23.8370453.65426
UAZirku Island Slug Catcher24.8707253.07181
UKBacton Slug Catchers52.859841.46191
UKEasington Slug Catcher53.362250.23492
UKHull Slug Catcher53.661800.10998
USCanyon Midstream Cryoplant Slug Catcher36.43756-99.15882
USCanyon Redcliff Plant Slug CatcherVolume 2500 bbl613536.21184-99.15533
USSlug Catcher31.27392-103.10827

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References

  1. Eaton, A. (2015). "Post-installed fiber optic pressure sensors on subsea production risers for severe slugging control" (PDF). OMAE 2015 Proceedings, St. John's, Canada.
  2. "Science direct slug catcher". science direct. Retrieved 29 September 2020.
  3. 1 2 "Gas processing and LNG". Gas processing news. Retrieved 29 September 2020.
  4. "Gas terminal Bacton Norfolk UK". Google Maps. Retrieved 29 September 2020.

http://www.glossary.oilfield.slb.com/en/Terms/s/slug_flow.aspx