GUIDE TO WORLD CRUDES: Statoil issues Snohvit condensate update

Nov. 7, 2011
Statoil has updated an assay of the condensate stream associated with natural gas being produced from Snohvit field in the Barents Sea.

Statoil has updated an assay of the condensate stream associated with natural gas being produced from Snohvit field in the Barents Sea.

The field lies on Blocks 7120 and 7121 in the Barents Sea, west northwest of the island of Hammerfest, Norway (OGJ, Apr. 9, 2007, p. 48). It sends natural gas via a 143-km (88.8-mile) subsea pipeline to the world's only gas liquefaction plant, on Melkoye Island. (A map of the field's location appears in OGJ, June 16, 2008, p. 46.)

The gas processing plant at the Hammerfest LNG plant received gas from Snohvit in August 2007 (OGJ, Aug. 27, 2007, p. 10), but full production was delayed by leaks in the cooling system until early 2008 (OGJ, Feb. 4, 2008, p. 10).

Snohvit produces without fixed or floating units in the Barents Sea. Instead, subsea production units stand on the seabed in water 250-345 m deep. A total of 20 wells are to produce gas from the Snohvit, Askeladd, and Albatross fields, says Statoil; 9 wells are planned on Snohvit, including 8 for production and 1 for reinjecting CO2.

Six of the producers and the CO2 injection well were drilled 2004-05, with the remaining two following this year. In addition, production wells were drilled on Albatross in 2005-06; this field also forms part of the Snohvit development. Snohvit and Albatross wells came on stream in 2007; Askeladd is due to come on stream in 2014-15.

Well stream from the Snohvit offshore fields arrives at the Hammerfest LNG plant under 70-90 bar and between –5° C. and 4° C. The stream first passes through this large slug catcher, which buffers or disperses liquid slugs and separates natural gas, condensate, and a water-monoethylene glycol mixture. The condensate flows to the condensate separator. Photograph from Statoil; by Harald Pettersen.

Partners in Snohvit are Statoil (operator, 33.53%), Petoro (30%), Total E&P Norge (18.40%), GDF Suez E&P Norge (12%), Hess Norge (3.26%), and RWE Dea Norge (2.81%).

Whole crude

Density at 15º C., kg/l.: 0.7339

Dry oil density15º C., kg/l.: 0.7339

API gravity at 60/60° F.: 61.3

Specific gravity at 60/60° F.: 0.7341

Sulfur, mass %: 0.020

Total acid no.: my KOH/g: <0.01

Reid vapor pressure, kPa: 48.6

Pour point, °C.: <–48

Flash point, °C.: <10

Vis. at 20° C., cst: 0.71

Vis. at 40° C., cst: 0.58

Nitrogen, mg/kg: 3

Hydrogen sulfide, mass %: ND1

Vanadium, mg/kg: <0.1

Nickel, mg/kg: <0.1

Sodium, mg/kg: <0.1

Mercury, µg/k: <1.0

Salt as NaCl, mg/l.: <5.0

Wax content, mass %: NA

Water content, mass %: <0.02

Pentanes to 65° C.

Yield on crude, mass %: 22.63

Yield on crude, vol %: 25.72

Density at 15° C., kg/l.: 0.6433

Specific gravity at 60/60° F.: 0.6433

API gravity at 60/60° F.: 88.5

Mercaptan sulfur, mg/kg: 8

n-Paraffins, mass %: 45.2

i-Paraffins, mass %: 48.5

Naphthenes, mass %: 4.5

Aromatics (incl. benzene), mass %: 1.8

n-Paraffins, vol %: 45.7

i-Paraffins, vol %: 49.1

Naphthenes, vol %: 3.8

Aromatics (incl. benzene), vol %: 1.3

Vapor pressure (DVPE1), kPa: 107.9

Research octane no. (RON): 76.3

Motor octane no. (MON): 73.8

Research octane no. (RON): 276.1

Motor octane no. (MON): 273.6

65-90° C.

Yield on crude, mass %: 15.4

Yield on crude, vol %: 15.62

Density at 15° C., kg/l.: 0.7206

Specific gravity at 60/60° F.: 0.7208

API gravity at 60/60° F.: 64.8

Sulfur, mass %: <0.001

Mercaptan sulfur, mg/kg: 7

n-Paraffins, mass %: 25.4

i-Paraffins, mass %: 27.5

Naphthenes, mass %: 35.1

Aromatics (incl. benzene), mass %: 11.9

Benzene, mass %: 11.3

n-Paraffins, vol %: 27.6

i-Paraffins, vol %: 29.5

Naphthenes, vol %: 33.1

Aromatics (incl. benzene), vol %: 9.8

Benzene, vol %: 9.2

Vapor pressure (DVPE1), kPa: 33.4

Research octane no. (RON): 68.5

Motor octane no. (MON): 66.4

Research octane no. (RON): 268.3

Motor (MON): 266.2

Nitrogen, mg/kg: <1

90-150° C.

Yield on crude, mass %: 32.82

Yield on crude, vol %: 31.73

Density at 15° C., kg/l.: 0.7561

Specific gravity at 60/60° F.: 0.7563

API gravity at 60/60° F.: 55.6

Sulfur, mass %: <0.001

Mercaptan sulfur, mg/kg: 5

n-Paraffins, mass %: 20.0

i-Paraffins, mass %: 23.4

Naphthenes, mass %: 37.3

Aromatics (incl. benzene), mass %: 19.3

Benzene, mass %: 0.5

n-Paraffins, vol %: 21.7

i-Paraffins, vol %: 24.9

Naphthenes, vol %: 36.6

Aromatics (incl. benzene), vol %: 16.8

Benzene, vol %: 0.5

Flash point, °C.: <10

Nitrogen, mg/kg: <1

150-180° C.

Yield on crude, mass %: 9.37

Yield on crude, vol %: 8.82

Density at 15° C., kg/l.: 0.7796

Specific gravity at 60/60° F.: 0.7799

API gravity at 60/60° F.: 49.9

Sulfur, mass %: 0.005

Mercaptan sulfur, mg/kg: 8

Copper corrosion: 1a

Total acid no., mg KOH/g: <0.01

Test conditions: True boiling point distillation

Equipment

The distillation up to 240° C. is performed according to D-2892.

Conditions*

Cut points are as follows:

• Atmospheric distillation: C5-180° C. AET.

• 100 Torr: 180-240° C. AET.

The atmospheric cut points are corrected to 760 mmHg.

Volume:

Volume expansion or contraction is normalized among fractions boiling at less than 150° C. in proportion to their yields. (Usually the "loss" is negative due to volume expansion.)

Loss:

Loss up to 240° C. AET is distributed with two-thirds in the gas-fraction and one-third in the first liquid fraction.


*AET = average equivalent temperature; Torr. ≈ 1 mmHg ≈ 0.0193 lbf/sq in.

n-Paraffins, mass %: 21.6

i-Paraffins, mass %: 29.7

Naphthenes, mass %: 27.1

Aromatics, mass %: 21.6

n-Paraffins, vol %: 23.3

i-Paraffins, vol %: 31.0

Naphthenes, vol %: 26.3

Aromatics, vol %: 19.4

Aromatics (HPLC1)

Total, mass %: 20.2

Monoaromatics, mass %: 20.2

Diaromatics, mass %: <0.1

Polycyclic aromatics, mass %: <0.1

Naphthalenes, vol %: 0.02

Aniline point, °C.: 52.3

Smoke point, mm: 26.0

Flash point, °C.: 41.5

Freezing point, °C.: <–60

Cetane index (D-976): 32.2

Calculated cetane index (D-4737): 37.1

Kin. vis. at 20° C., cst: 1.08

Kin. vis. at 50° C., cst: 0.76

Nitrogen, mg/kg: <1

Distillation D-86 (50%), °C.: 159.6

180-240° C.

Yield on crude, mass %: 10.93

Yield on crude, vol %: 10.02

Density at 15° C., kg/l.: 0.8003

Specific gravity at 60/60° F.: 0.8006

API gravity at 60/60° F.: 45.2

Sulfur, mass %: 0.017

Mercaptan sulfur, mg/kg: 5

Copper corrosion: 1a

Total acid no., mg KOH/g: <0.01

Aromatics (HPLC1)

Total, mass %: 18.0

Monoaromatics, mass %: 15.6

Diaromatics, mass %: 2.4

Polycyclic aromatics, mass %: <0.1

Naphthalenes, vol %: 1.57

Aniline point, °C.: 62.8

Smoke point, mm: 23.0

Freezing point, °C.: –50.0

Cloud point, °C.: <–51

Cold-filter plugging point, °C.: <–50

Pour point, °C.: <–48

Cetane no.: 50.3

Cetane index (D-976): 44.9

Calculated cetane index (D-4737): 46.6

Kin. vis. at 20° C., cst: 1.80

Kin. vis. at 50° C., cst: 1.15

Nitrogen, mg/kg: <1

Distillation D-86 (50%), °C.: 201.3

240°+ C.

Yield on crude, mass %: 8.03

Yield on crude, vol %: 7.04

Density at 15° C., kg/l.: 0.8372

Specific gravity at 60/60° F.: 0.8376

API gravity at 60/60° F.: 37.4

Sulfur, mass %: 0.144

Total acid no., mg KOH/g: <0.01

Aromatics (HPLC1)

Total, mass %: 21.6

Monoaromatics, mass %: 12.7

Diaromatics, mass %: 8.4

Polycyclic aromatics, mass %: 0.5

Aniline point, °C.: 76.0

Watson K-factor: 11.9

Cloud point, °C.: -5

Cold-filter plugging point, °C.: –9

Pour point, °C.: –11

Cetane no.: 58.6

Cetane index (D-976): 52.7

Calculated cetane index (D-4737): 57.8

Conradson carbon residue, mass %: <0.1

Kin. vis. at 20° C., cst: 5.52

Kin. vis. at 50° C., cst: 2.76

Nitrogen, mg/kg: 30

Basic nitrogen, mass %: 0.001

Refracxtive index at 67º C.: 1.448

Vanadium, mg/kg: <0.1

Nickel, mg/kg: <0.1

Asphaltenes, mass %: NA

n-Pentanes insolubes, mass %: <0.01

Ash, mass %: <0.001

Distillation D-86 (50%), °C.: 272.6

Composition, mass %

Normal paraffins

Methane: <0.01

Ethane: <0.01

Propane: <0.01

Butane: 1.05

Pentane: 8.57

Hexane: 5.05

Heptane: 3.56

Octane: 2.68

Nonane: 1.82

Total n-paraffins: 22.73

C4 hydrocarbons

i-Butane: 0.05

Test methods: Snohvit condensate

Density at 15° C., kg/l.: D-4052/D-5002

Dry oil density at 15° C., kg/l.: IP479

Total sulfur, mass %: D-4294

Total sulfur, mass %: D-5453 for sulfur content less than 0.01%

Hydrogen sulfide, pos./neg.: lead acetate paper

Mercaptan sulfur, mg/kg: D-3227

n-Paraffins, mass %: GC*

i-Paraffins, mass %: GC

Naphthenes, mass %: GC

Aromatics, mass %: GC

Benzene, mass %: GC

Aromatics (HPLC*), mass %: D-6591

Naphthalene, vol %: D-1840

Watson K: UOP 375

Vapor pressure (DVPE*), kPa: D-5191

Reid vapor pressure, kPa: D-323

Flash point (Pensky Martens), °C.: D-93

Freezing point, °C.: D-2386

Cloud point, °C.: D-5772

Pour point, °C.: D-5853/D-5950

Cold filter plugging point, °C.: IP 309

Kin. viscosity at 20° C., cSt: D-445

Kin. viscosity at 40° C., cSt: D-445

Kin. viscosity at 50° C., cSt: D-445

Kin. viscosity at 80° C., cSt: D-445

Kin. viscosity at 100° C., cSt: D-445

Aniline point, °C.: D-611

Research octane number (RON): D-2699

Motor octane number (MON): D-2700

Cetane index: D-976

Calculated cetane index: D-4737 Method A

Cetane number: D-613

Smoke point, mm: D-1322

Distillation of whole crude up to 375° C.: D-2892

Distillation of individual fractions: D-86

Simulated distillation: IP PM-CF/98

Total acid number (TAN), mgKOH/g: D-664

Copper corrosion: D-130

Nitrogen, <100 mg/kg: D-4629

Nitrogen, >40 mg/kg: D-5762

Basic nitrogen, mass %: UOP 269

Vanadium (V), mg/kg: ICP

Nickel (Ni), mg/kg: ICP

Sodium (Na), mg/kg: ICP

Mercury (Hg), μg/kg: FIMS* (with in-house method)

Salt as NaCl, mg/l.: IP 265

Color (ASTM): D-1500

Carbon residue (micromethod), mass %: D-4530

Asphaltenes, mass %: IP 143

n-C5 insolubles, mass %: D-4055

Ash, mass %: D-482

Penetration at 25° C., 0.1 mm: D-1321

Refractive index at 67° C.: Abbe refractometer

Wax content, mass %: UOP 46 (mod. acetone precip.)

Water content, mass %: D-4928

Compositional analysis of crude oil, mass %: D-5134

*GC = gas chromatograph; HPLC = high performance liquid chromatography; DVPE = dry vapor pressure equivalent; ICP = inductively coupled plasma; FIMS = field ionization mass spectrometry.

C5 hydrocarbons

Isoparaffins

2,2-Dimethylpropane: 0.04

i-Pentane: 7.36

Total C5 i-paraffins: 7.40

Naphthenes

Cyclopentane: 0.66

C6 hydrocarbons

Isoparaffins

2,2-Dimethylbutane: 0.37

2,3-Dimethylbutane: 0.56

2-Methylpentane: 3.32

3-Methylpentane: 1.90

Total C6 i-paraffins: 6.14

Naphthenes

Methylcyclopentane (incl. 2,2-Dimethylpentane): 2.68

Cyclohexane: 2.82

Total C6 naphthenes: 5.51

Aromatics

Benzene: 2.27

C7 hydrocarbons

Isoparaffins

2,2,3-Trimethylbutane: 0.04

3,3-Dimethylpentane: 0.07

2,4-Dimethylpentane: 0.24

2-Methylhexane: 1.47

2,3-Dimethylpentane: 0.27

3-Methylhexane: 1.44

Total C7 i-paraffins: 3.52

Naphthenes

cis-1,3-Dimethylcyclopentane: 0.44

trans-1,3-Dimethylcyclopentane: 0.40

trans-1,2-Dimethylcyclopentane: 0.82

Methylcyclohexane: 4.74

Ethylcyclopentane: 0.26

1,1-Dimethylcyclopentane: 0.24

Total C7 naphthenes: 6.9

Aromatics

Toluene: 3.29

C8 hydrocarbons

Isoparaffins

2,2,4-Trimethylpentane: <0.01

2,5-Dimethylhexane: 0.17

2,4-Dimethylhexane: 0.20

3,4-Dimethylhexane: 0.03

3,3-Dimethylhexane: 0.06

2,3-Dimethylhexane (incl. naphthenic compound): 0.18

2-Methyl-3-ethylpentane: 0.04

2-Methylheptane: 1.14

4-Methylheptane: 0.35

3-Methylheptane: 3<0.01

2,3,4-Trimethylpentane: 0.02

Total C8 i-paraffins: 2.19

Naphthenes

1,1,3-Trimethylcyclopentane (incl. 2,2-Dimethylhexane): 0.27

trans, cis-1,2,4-Trimethylcyclopentane: 0.19

trans,cis-1,2,3-Trimethylcyclopentane: 0.20

trans-1,4-Dimethylcyclohexane: 0.38

1,1-Dimethylcyclohexane: 0.11

trans-1-Methyl-3-ethylcyclopentane: 0.09

cis-1-Methyl-3-ethylcyclopentane: 0.07

trans-1-Methyl-2-ethylcyclopentane: 0.17

trans-1,2-Dimethylcyclohexane: 0.36

2-Propylcyclopentane: 0.03

cis-1,2-Dimethylcyclohexane: 0.16

Ethylcyclohexane: 0.74

1-Propylcyclopentane: 0.39

cis,cis-1,2,4-Trimethylcyclopentane: <0.01

1-Methyl-1-ethylcyclopentane: 0.02

cis-1,3-Dimethylcyclohexane (incl. naphthenic compound): 31.64

Total C8 naphthenes: 4.82

Aromatics

Ethylbenzene: 0.52

m-Dimethylbenzene (m-xylene): 1.34

p-Dimethylbenzene (p-xylene): 0.51

o-Dimethylbenzene (o-Xylene): 0.54

Total C8 aromatics: 2.91

C9 hydrocarbons

Isoparaffins

3,5-Dimethylheptane: 0.33

4-Methyloctane: 0.25

2-Methyloctane: 0.40

3-Methyloctane: 0.47

2,3,4-Trimethylhexane: <0.01

Unidentified paraffin: 0.10

Total C9 i-paraffins: 1.55

Naphthenes

1,1,3-Trimethylcyclohexane: 0.27

1-Methyl-2-propylcyclopentane: 0.10

1-Methyl-3-ethylcyclohexane: 0.26

1-Methyl-4-ethylcyclohexane: 0.16

1,1,4-Trimethylcyclohexane: 0.10

Unidentified naphthenes: 0.11

Total C9 naphthenes: 1.00

Total identified: 70.93
Total unidentified: 0.14

Total C10+: 28.93

1ND = not detectable; NA = not analyzed due to nature of the sample; HPLC = high performance liquid chromatography; DVPE = dry vapor pressure equivalent. 2Corrected in accordance with EN 228. 3Not possible to distinguish between 3-Methylheptane and 1,3-Dimethylcyclohexane.

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