GUIDE TO WORLD CRUDES: Statoil publishes Aasgard Blend assay

Jan. 18, 2010
Statoil late last year published an assay of its Aasgard Blend, a commingling of production from Smorbukk, Smorbukk South, Midgard, Mikkel, Kristin, Yttergryta, and Tyrihans fields in the Norwegian Sea.
Statoil late last year published an assay of its Aasgard Blend, a commingling of production from Smorbukk, Smorbukk South, Midgard, Mikkel, Kristin, Yttergryta, and Tyrihans fields in the Norwegian Sea.

Aasgard field lies on the Halten Bank, about 200 km off mid-Norway and 50 km south of Heidrun field (map).

The field consists of Midgard, Smorbukk, and Smorbukk South discoveries. Midgard straddles Blocks 6507/11 and 6407/2, while the two other deposits lie in Block 6506/11.

Statoil reports that Aasgard ranks among the largest developments on the Norwegian Continental Shelf, embracing a total of 52 wells drilled through 16 seabed templates.

Legend:

1ND = not detectable; HPLC = high performance liquid chromatography; DVPE = dry vapor pressure equivalent. 2Corrected in accordance with EN 228. 3Calculated density for 525+ fraction.

Saga Petroleum discovered Midgard in 1981, with Statoil finding Smorbukk and Smorbukk South in 1984 and 1985, respectively. The two companies unitized the three fields into a single production license in 1995, with Statoil as operator.

On Feb. 8, 1999, the Aasgard A oil production ship arrived on the field and became operational on May 19. Gas production from the semi-submersible Aasgard B platform began on Oct. 1, 2000.

The overall Aasgard development consists of:

• Development of the field.

• Aasgard transport gas pipeline from the field to processing at Karsto north of Stavanger.

• Karsto expansion.

• Europipe II gas trunkline from Karsto to Dornum on the German coast.

Crude oil, condensate, and natural gas are produced from Aasgard. Crude and condensate form Aasgard Blend, a light oil.

Average production of 200,000 b/d is pumped from storage tanks into shuttle tankers, which sail between the fields and the different refineries.

Gas from Aasgard flows through Aasgard transport to Karsto processing, which separates heavier components—ethane, propane, butane, and naphthas. Dry gas is piped to continental Europe.

The Aasgard development links the Halten Bank area to Norway's gas transport system in the North Sea.

Whole crude

Density at 15° C., kg/l.: 0.7928

Specific gravity at 60/60° F.: 0.7931

Gravity at 60/60° F., °API: 46.9

Dry oil density at 15° C., kg/l.: 0.7928

Sulfur, mass %: 0.188

Total acid number, mg KOH/g: <0.01

Reid vapor pressure, kPa: 65.7

Pour point, °C.: –33

Kinematic viscosity at 20° C., cst: 1.98

Kinematic viscosity at 50° C., cst: 1.42

Nitrogen, mg/kg: 300

Hydrogen sulfide, mass %: ND1

Vanadium, mg/kg: 1.0

Nickel, mg/kg: 0.1

Sodium, mg/kg: 1.3

Salt as NaCl, mg/l.: 5.5

Wax content, mass %: <5

Flash point, °C.: <10

Water content, mass %: <0.02

Mercury, μg/kg: 31

Pentanes to 65° C.

Yield on crude, mass %: 7.24

Yield on crude, vol %: 8.74

Density at 15° C., kg/l.: 0.6463

Specific gravity at 60/60° F.: 0.6463

Gravity at 60/60° F., °API: 87.4

Mercaptan sulfur, mg/kg: <3

n-Paraffins, mass %: 48.1

i-Paraffins, mass %: 44.1

Naphthenes, mass %: 6.1

Aromatics (incl. benzene), mass %: 1.7

n-Paraffins, vol %: 49.0

i-Paraffins, vol %: 44.6

Naphthenes, vol %: 5.1

Aromatics (incl. benzene), vol %: 1.3

Vapor pressure (DVPE), kPa: 107.8

Research octane number: 75.4

Motor octane number: 73.0

Research octane number, 275.2

Motor octane number, 272.8

65-90° C.

Yield on crude, mass %: 6.96

Yield on crude, vol %: 7.54

Density at 15° C., kg/l.: 0.7206

Specific gravity at 60/60° F.: 0.7208

Gravity at 60/60° F., °API: 64.8

Sulfur, mass %: <0.001

Mercaptan sulfur, mg/kg: <3

n-Paraffins, mass %: 26.3

i-Paraffins, mass %: 25.7

Naphthenes, mass %: 39.9

Aromatics (incl. benzene), mass %: 8.2

Benzene, mass %: 6.9

n-Paraffins, vol %: 28.5

i-Paraffins, vol %: 27.4

Naphthenes, vol %: 37.5

Aromatics (incl. benzene), vol %: 6.7

Benzene, vol %: 5.6

Vapor pressure (DVPE), kPa: 33.1

Research octane number: 67.5

Motor octane number: 65.6

Research octane number: 267.3

Motor octane number: 265.4

Nitrogen, mg/kg: <1

90-150° C.

Yield on crude, mass %: 20.04

Yield on crude, vol %: 20.58

Density at 15° C., kg/l.: 0.7601

Specific gravity at 60/60° F.: 0.7603

Gravity at 60/60° F., °API: 54.6

Sulfur, mass %: <0.001

Mercaptan sulfur, mg/kg: <3

n-Paraffins, mass %: 20.0

i-Paraffins, mass %: 21.1

Naphthenes, mass %: 37.8

Aromatics (incl. benzene), mass %: 21.1

Benzene, mass %: 0.5

n-Paraffins, vol %: 21.8

i-Paraffins, vol %: 22.5

Naphthenes, vol %: 37.2

Aromatics (incl. benzene), vol %: 18.4

Benzene, vol %: 0.4

Flash point, °C.: <10

Nitrogen, mg/kg: <1

150-180° C.

Yield on crude, mass %: 7.37

Yield on crude, vol %: 7.46

Density at 15° C., kg/l.: 0.7839

Specific gravity at 60/60° F.: 0.7842

Gravity at 60/60° F., °API: 48.9

Sulfur, mass %: 0.001

Mercaptan sulfur, mg/kg: <3

Copper corrosion: 1a

Total acid number, mg KOH/g: <0.01

n-Paraffins, mass %: 21.2

i-Paraffins, mass %: 25.1

Naphthenes, mass %: 29.3

Aromatics, mass %: 24.4

n-Paraffins, vol %: 23.0

i-Paraffins, vol %: 26.4

Naphthenes, vol %: 28.6

Aromatics, vol %: 22.0

Aromatics (HPLC)

Total, mass %: 22.0

Monoaromatics, mass %: 22.0

Diaromatics, mass %: <0.1

Polycyclic aromatics, mass %: <0.1

Naphthalenes, vol %: 0.03

Aniline point, °C.: 49.9

Smoke point, mm: 23.0

Flash point, °C.: 40.0

Freezing point, °C.: <–60

Cetane index (D-976): 30.7

Calculated cetane index (D-4737): 35.4

Kinematic viscosity at 20° C., cst: 1.08

Kinematic viscosity at 50° C., cst: 0.76

Nitrogen, mg/kg: <1

Distillation D-86 (50%), °C.: 160.1

180-240° C.

Yield on crude, mass %: 12.04

Yield on crude, vol %: 11.83

Density at 15° C., kg/l.: 0.8072

Specific gravity at 60/60° F.: 0.8075

Gravity at 60/60° F., °API: 43.7

Sulfur, mass %: 0.011

Mercaptan sulfur, mg/kg: <3

Copper corrosion: 1a

Total acid number, mg KOH/g: <0.01

Aromatics (HPLC)

Total, mass %: 20.7

Monoaromatics, mass %: 16.9

Diaromatics, mass %: 3.8

Polycyclic aromatics, mass %: <0.1

Naphthalenes, vol %: 2.46

Aniline point, °C.: 59.5

Smoke point, mm: 22.0

Freezing point, °C.: –50.0

Cloud point, °C.: <–51

Cold-filter plugging point, °C.: <–50

Pour point, °C.: <–48

Cetane number: 48.4

Cetane index (D-976): 43.4

Calculated cetane index (D-4737): 44.1

Kinematic viscosity at 20° C., cst: 1.83

Kinematic viscosity at 50° C., cst: 1.17

Nitrogen, mg/kg: <1

Distillation D-86 (50%), °C.: 204.3

240-320° C.

Yield on crude, mass %: 15.21

Yield on crude, vol %: 14.35

Density at 15° C., kg/l.: 0.8405

Specific gravity at 60/60° F.: 0.8409

Gravity at 60/60° F., °API: 36.8

Sulfur, mass %: 0.099

Total acid number, mg KOH/g: <0.01

Aromatics (HPLC)

Total, mass %: 24.3

Monoaromatics, mass %: 13.5

Diaromatics, mass %: 10.5

Polycyclic aromatics, mass %: 0.3

Aniline point, °C.: 71.8

Cloud point, °C.: –17

Cold-filter plugging point, °C.: –19

Pour point, °C.: –15

Cetane number, 56.5

Cetane index (D-976): 51.1

Calculated cetane index (D-4737): 54.8

Kinematic viscosity at 20° C., cst: 4.80

Kinematic viscosity at 50° C., cst: 2.47

Nitrogen, mg/kg: 12

Basic nitrogen, mass %: <0.001

Distillation D-86 (50%), °C.: 270.4

320-375° C.

Yield on crude, mass %: 7.52

Yield on crude, vol %: 6.89

Density at 15° C., kg/l.: 0.8650

Specific gravity at 60/60° F.: 0.8654

Gravity at 60/60° F., °API: 32.0

Sulfur, mass %: 0.370

Total acid number, mg KOH/g: 0.02

Aromatics (HPLC)

Total, mass %: 24.2

Monoaromatics, mass %: 13.3

Diaromatics, mass %: 7.9

Polycyclic aromatics, mass %: 3.0

Aniline point, °C.: 83.7

Watson K-factor: 11.9

Cloud point, °C.: 11

Cold-filter plugging point, °C.: 11

Pour point, °C.: 12

Cetane number: 61.1

Cetane index (D-976): 52.6

Calculated cetane index: 65.2

Conradson carbon residue, mass %: <0.10

Kinematic viscosity at 20° C., cst: 15.6

Kinematic viscosity at 50° C., cst: 6.15

Kinematic viscosity at 100° C., cst: 2.24

Nitrogen, mg/kg: 183

Basic nitrogen, mass %: 0.005

Refractive index at 67° C.: 1.464

Distillation D-86 (50%), °C.: 335.2

375-420° C.

Yield on crude, mass %: 5.01

Yield on crude, vol %: 4.50

Density at 15° C., kg/l.: 0.8824

Specific gravity at 60/60° F.: 0.8828

Gravity at 60/60° F, °API: 28.8

Sulfur, mass %: 0.417

Total acid number, mg KOH/g: 0.01

Aniline point, °C.: 93.0

Watson K-factor: 12.0

Pour point, °C.: 30

Conradson carbon residue, mass %: <0.10

Kinematic viscosity at 50° C., cst: 14.8

Kinematic viscosity at 100° C., cst: 4.62

Vanadium, mg/kg: <0.1

Nickel, mg/kg: <0.1

Nitrogen, mg/kg: 430

Basic nitrogen, mass %: 0.012

Refractive index at 67° C.: 1.473

420-525° C.

Yield on crude, mass %: 8.50

Yield on crude, vol %: 7.48

Density at 15° C., kg/l.: 0.9014

Specific gravity at 60/60° F.: 0.9019

Gravity at 60/60° F., °API: 25.4

Sulfur, mass %: 0.567

Total acid number, mg KOH/g: <0.01

Aniline point, °C.: 98.0

Watson K-factor: 12.0

Pour point, °C.: 39

Conradson carbon residue, mass %: <0.10

Kinematic viscosity at 50° C., cst: 40.0

Kinematic viscosity at 100° C., cst: 8.25

Vanadium, mg/kg: <0.1

Nickel, mg/kg: <0.1

Nitrogen, mg/kg: 890

Basic nitrogen, mass %: 0.021

Refractive index at 67° C.: 1.484

375°+ C.

Yield on crude, mass %: 19.66

Yield on crude, vol %: 17.01

Density at 15° C., kg/l.: 0.9167

Specific gravity at 60/60° F.: 0.9172

Gravity at 60/60° F., °API: 22.8

Sulfur, mass %: 0.740

Total acid number, mg KOH/g: 0.02

Aniline point, °C.: 96.5

Watson K-factor: 12.0

Pour point, °C.: 42

Conradson carbon residue, mass %: 3.46

Asphaltenes, mass %: <0.50

n-Pentane insolubles, mass %: 0.6

Ash, mass %: 0.017

Kinematic viscosity at 50° C., cst: 79.7

Kinematic viscosity at 100° C., cst: 13.1

Vanadium, mg/kg: 6.0

Nickel, mg/kg: 0.5

Nitrogen, mg/kg: 1,470

Basic nitrogen, mass %: 0.034

Penetration at 25° C., mm: 0.1

Refractive index at 67° C.: 1.501

525°+ C.

Yield on crude, mass %: 6.15

Yield on crude, vol %: 5.03

Density at 15° C., kg/l.: 30.9688

Specific gravity at 60/60° F.: 0.9694

Gravity at 60/60° F., °API: 14.5

Sulfur, mass %: 1.193

Aniline point, °C.: 99.5

Watson K-factor: 11.7

Pour point, °C.: 33

Conradson carbon residue, mass %: 11.0

Asphaltenes, mass %: 0.90

n-Pentane insolubles, mass %: 3.3

Ash, mass %: 0.026

Kinematic viscosity at 80° C., cst: 395

Kinematic viscosity at 100° C., cst: 136

Vanadium, mg/kg: 21

Nickel, mg/kg: 1.6

Nitrogen, mg/kg: 3,190

Basic nitrogen, mass %: 0.073

Penetration at 25° C., mm: >300

Composition, mass %

Normal paraffins

Methane: <0.01

Ethane: 0.03

Propane: 0.59

Butane: 2.43

Pentane: 2.71

Hexane: 2.27

Heptane: 1.97

Octane: 1.74

Nonane: 1.34

Total n-paraffins: 13.07

C4 hydrocarbons

i-Butane: 0.74

C5 hydrocarbons

Isoparaffins

2,2-Dimethylpropane: 0.01

i-Pentane: 1.98

Total C5 i-paraffins: 2.00

Naphthenes

Cyclopentane: 0.24

C6 hydrocarbons

Isoparaffins

2,2-Dimethylbutane: 0.06

2,3-Dimethylbutane: 0.18

2-Methylpentane: 1.28

3-Methylpentane: 0.75

Total C6 i-paraffins: 2.27

Naphthenes

Methylcyclopentane
(incl. 2,2-Dimethylpentane): 1.23

Cyclohexane: 1.75

Total C6 naphthenes: 2.98

Aromatics

Benzene: 0.78

C7 hydrocarbons

Isoparaffins

2,2,3-Trimethylbutane: 0.01

3,3-Dimethylpentane: 0.02

2,4-Dimethylpentane: 0.09

2-Methylhexane: 0.65

2,3-Dimethylpentane: 0.17

3-Methylhexane: 0.69

Total C7 i-paraffins: 1.64

Naphthenes

cis-1,3-Dimethylcyclopentane: 0.24

trans-1,3-Dimethylcyclopentane: 0.22

trans-1,2-Dimethylcyclopentane: 0.43

Methylcyclohexane: 2.85

Ethylcyclopentane: 0.15

1,1-Dimethylcyclopentane: 0.12

Total C7 naphthenes: 4.02

Aromatics

Toluene: 2.01

C8 hydrocarbons

Isoparaffins

2,2,4-Trimethylpentane: <0.01

2,5-Dimethylhexane: 0.09

2,4-Dimethylhexane: 0.09

3,4-Dimethylhexane: 0.02

3,3-Dimethylhexane: 0.02

2,3-Dimethylhexane
(incl. naphthenic compound): 0.11

2-Methyl-3-ethylpentane: 0.02

2-Methylheptane: 0.67

4-Methylheptane: 0.19

3-Methylheptane: 0.38

2,3,4-Trimethylpentane: 0.01

Total C8 isoparaffins: 1.61

Naphthenes

1,1,3-Trimethylcyclopentane
(incl. 2,2-Dimethylhexane): 0.12

trans, cis-1,2,4-Trimethylcyclopentane: 0.12

trans,cis-1,2,3-Trimethylcyclopentane: 0.11

trans-1,4-Dimethylcyclohexane: 0.20

1,1-Dimethylcyclohexane: 0.07

trans-1-Methyl-3-ethylcyclopentane: 0.04

cis-1-Methyl-3-ethylcyclopentane: 0.04

trans-1-Methyl-2-ethylcyclopentane: 0.10

trans-1,2-Dimethylcyclohexane: 0.23

2-Propylcyclopentane: 0.02

cis-1,2-Dimethylcyclohexane: 0.12

Ethylcyclohexane: 0.87

1-Propylcyclopentane: <0.01

cis,cis-1,2,4-Trimethylcyclopentane: 0.02

1-Methyl-1-ethylcyclopentane: 0.01

cis-1,3-Dimethylcyclohexane
(incl. naphthenic compound): 0.54

Total C8 naphthenes: 2.62

Aromatics

Ethylbenzene: 0.38

m-Dimethylbenzene (m-xylene): 1.06

p-Dimethylbenzene (p-xylene): 0.35

o-Dimethylbenzene (o-xylene): 0.44

Total C8 aromatics: 2.23

C9 hydrocarbons

Isoparaffins

3,5-Dimethylheptane: 0.18

4-Methyloctane: 0.17

2-Methyloctane: 0.25

3-Methyloctane: 0.30

2,3,4-Trimethylhexane: <0.01

Unidentified paraffin: 0.08

Total C9 i-paraffins: 0.99

Naphthenes

1,1,3-Trimethylcyclohexane: 0.18

1-Methyl-2-propylcyclopentane: 0.08

1-Methyl-3-ethylcyclohexane: 0.19

1-Methyl-4-ethylcyclohexane: 0.11

1,1,4-Trimethylcyclohexane: 0.08

Unidentified Naphthenes: 0.06

Total C9 naphthenes: 0.71

Total identified: 37.90
Total unidentified: 0.18

Total C10+: 61.92

Editor's note: Statoil's assay report contained the following: "A commercial assay was carried out on a representative sample of the crude. The contents of this report are for guidance only and Statoil accepts no responsibility for any errors that it may contain."

More Oil & Gas Journal Current Issue Articles
More Oil & Gas Journal Archives Issue Articles
View Oil and Gas Articles on PennEnergy.com