StatoilHydro late last year published an assay of its Troll Blend crude oil, a commingling of Troll B, Troll C, Fram, and Kvitebjorn fields off Norway and operated by the company.
Troll field lies in the northern part of the North Sea, about 65 km west of Kollsnes, near Bergen (map). It consists of the main Troll East and Troll West structures in Blocks 31/2, 31/3, 31/5 and 31/6.
Legend: 1ND = not detectable; NA = not analyzed due to instrument problems; HPLC = high performance liquid chromatography; DVPE = dry vapor pressure equivalent. 2Corrected in accordance with EN 228. 3Calculated density for 525+ fraction. |
The field contains, according to StatoilHydro, about 40% of total gas reserves on the Norwegian continental shelf, one of the largest oil fields on the shelf. In 2002 the oil production was more than 400,000 b/d. In addition to Troll A, B, and C platforms, StatoilHydro operates the landfall pipelines. Gassco operates the gas processing plant at Kollsnes on behalf of Gassled. StatoilHydro is a technical services provider for Kollsnes operations.
StatoilHydro expects the reservoirs 1,400 m below sea level to produce for at least another 70 years.
Proved
When Block 31/2 was awarded in April 1979, Norske Shell was chosen as operator. A large gas find with an underlying oil zone was proven later that year. The block was declared commercial in 1983.
Neighboring blocks were awarded to StatoilHydro, Norsk Hydro, and Saga Petroleum in 1983. Block 31/2 contains 32% of Troll field's reserves, while the remaining 68% lies in the three other blocks.
License terms for Block 31/2 specified that StatoilHydro could take over as operator for this acreage 8-10 years after a discovery had been declared commercial.
In 1985, the two licenses were unitized so that Troll could be developed as a single field.
StatoilHydro took over as production operator for Troll gas on June 19, 1996, while Hydro started production from Troll oil in fall 1995.
Whole crude
Density at 15° C., kg/l.: 0.8577
Specific gravity at 60/60° F.: 0.8581
API gravity at 60/60° F.: 33.4
Dry oil density at 15° C., kg/l.: 0.8573
Sulfur, mass %: 0.180
Total acid no., mg KOH/g: 0.64
Reid vapor pressure, kPa: 33.6
Pour point, °C.: –9
Kin. vis. at 20° C., cst: 9.16
Kin. vis. at 40° C., cst: 4.75
Nitrogen, mg/kg: NA
Hydrogen sulfide, mass %: ND1
Vanadium, mg/kg: 0.6
Nickel, mg/kg: 0.6
Sodium, mg/kg: 28
Salt as NaCl, mg/l.: 94
Wax content, mass %: 5.7
Flash point, °C.: <10
Water content, mass %: 0.21
Pentanes to 65° C.
Yield on crude, mass %: 2.16
Yield on crude, vol %: 2.81
Density at 15° C., kg/l.: 0.6548
Specific gravity at 60/60° F.: 0.6548
API gravity at 60/60° F.: 84.6
Mercaptan sulfur, mg/kg: <3
n-Paraffins, mass %: 40.8
i-Paraffins, mass %: 43.5
Naphthenes, mass %: 12.9
Aromatics (incl. benzene), mass %: 2.8
n-Paraffins, vol %: 42.5
i-Paraffins, vol %: 44.4
Naphthenes, vol %: 11.0
Aromatics (incl. benzene), vol %: 2.1
Vapor pressure (DVPE), kPa: 117.8
Research octane no.: 77.8
Motor octane no.: 75.7
Research octane no.: 277.6
Motor octane no.: 275.5
65-90° C.
Yield on crude, mass %: 2.77
Yield on crude, vol %: 3.22
Density at 15° C., kg/l.: 0.7358
Specific gravity at 60/60° F.: 0.7360
API gravity at 60/60° F.: 60.8
Sulfur, mass %: <0.001
Mercaptan sulfur, mg/kg: <3
n-Paraffins, mass %: 15.6
i-Paraffins, mass %: 22.3
Naphthenes, mass %: 54.5
Aromatics (incl. benzene), mass %: 7.5
Benzene, mass %: 5.9
n-Paraffins, vol %: 17.2
i-Paraffins, vol %: 24.2
Naphthenes, vol %: 52.2
Aromatics (incl. benzene), vol %: 6.3
Benzene, vol %: 4.9
Vapor pressure (DVPE), kPa: 31.1
Research octane no.: 74.0
Motor octane no.:72.7
Research octane no.: 273.8
Motor octane no.: 272.5
Nitrogen, mg/kg: NA
90-150° C.
Yield on crude, mass %: 10.08
Yield on crude, vol %: 11.20
Density at 15° C., kg/l.: 0.7692
Specific gravity at 60/60° F.: 0.7694
API gravity at 60/60° F.: 52.4
Sulfur, mass %: 0.002
Mercaptan sulfur, mg/kg: <3
n-Paraffins, mass %: 12.7
i-Paraffins, mass %: 17.7
Naphthenes, mass %: 50.3
Aromatics (incl. benzene), mass %: 19.4
Benzene, mass %: 0.4
n-Paraffins, vol %: 13.9
i-Paraffins, vol %: 19.0
Naphthenes, vol %: 49.9
Aromatics (incl. benzene), vol %: 17.1
Benzene, vol %: 0.3
Flash point, °C.: <10
Nitrogen, mg/kg: NA
150-180° C.
Yield on crude, mass %: 4.99
Yield on crude, vol %: 5.38
Density at 15° C., kg/l.: 0.7954
Specific gravity at 60/60° F.: 0.7957
API gravity at 60/60° F.: 46.3
Sulfur, mass %: 0.008
Mercaptan sulfur, mg/kg: <3
Copper corrosion: 1a
Total acid no., mg KOH/g: <0.01
n-Paraffins, mass %: 13.6
i-Paraffins, mass %: 21.3
Naphthenes, mass %: 41.0
Aromatics, mass %: 24.2
n-Paraffins, vol %: 14.9
i-Paraffins, vol %: 22.6
Naphthenes, vol %: 40.5
Aromatics, vol %: 22.1
Aromatics (HPLC)
Total, mass %: NA
Monoaromatics, mass %: NA
Diaromatics, mass %: NA
Polycyclic aromatics, mass %: NA
Naphthalenes, vol %: 0.04
Aniline point, °C.: 45.0
Smoke point, mm: 21.5
Flash point, °C.: 36.5
Freezing point, °C.: <-60
Cetane index (D-976): 26.1
Calculated cetane index (D-4737): 30.4
Kin. vis. at 20° C., cst: 1.11
Kin. vis. at 50° C., cst: 0.78
Nitrogen, mg/kg: NA
Distillation D-86 (50%), °C.: 160.4
180-240° C.
Yield on crude, mass %: 10.65
Yield on crude, vol %: 11.08
Density at 15° C., kg/l.: 0.8248
Specific gravity at 60/60° F.: 0.8251
API gravity at 60/60° F.: 40.0
Sulfur, mass %: 0.016
Mercaptan sulfur, mg/kg: <3
Copper corrosion: 1a
Total acid no., mg KOH/g: 0.01
Aromatics (HPLC)
Total, mass %: NA
Monoaromatics, mass %: NA
Diaromatics, mass %: NA
Polycyclic aromatics, mass %: NA
Naphthalenes, vol %: 2.83
Aniline point, °C.: 54.8
Smoke point, mm: 20.0
Freezing point, °C.: –57.0
Cloud point, °C.: <–50
Cold-filter plugging point, °C.: <–50
Pour point, °C.: <–50
Cetane no.: 41.1
Cetane index (D-976): 37.5
Calculated cetane index (D-4737): 37.6
Kin. vis. at 20° C., cst: 1.95
Kin. vis. at 50° C., cst: 1.23
Nitrogen, mg/kg: NA
Distillation D-86 (50%), °C.: 206.2
240-320° C.
Yield on crude, mass %: 19.86
Yield on crude, vol %: 19.80
Density at 15° C., kg/l.: 0.8601
Specific gravity at 60/60° F.: 0.8605
API gravity at 60/60° F.: 32.9
Sulfur, mass %: 0.072
Total acid no., mg KOH/g: 0.15
Aromatics (HPLC)
Total, mass %: NA
Monoaromatics, mass %: NA
Diaromatics, mass %: NA
Polycyclic aromatics, mass %: NA
Aniline point, °C.: 65.0
Cloud point, °C.: –25
Cold-filter plugging point, °C.: –25
Pour point, °C.: –24
Cetane no.: 49.7
Cetane index (D-976): 45.3
Calculated cetane index (D-4737): 47.0
Kin. vis. at 20° C., cst: 5.50
Kin. vis. at 50° C., cst: 2.69
Nitrogen, mg/kg: NA
Basic nitrogen, mass %: <0.001
Distillation D-86 (50%), °C.: 272.9
320-375° C.
Yield on crude, mass %: 11.18
Yield on crude, vol %: 10.81
Density at 15° C., kg/l.: 0.8869
Specific gravity at 60/60° F.: 0.8874
API gravity at 60/60° F.: 28.0
Sulfur, mass %: 0.207
Total acid no., mg KOH/g: 0.76
Aromatics (HPLC)
Total, mass %: NA
Monoaromatics, mass %: NA
Diaromatics, mass %: NA
Polycyclic aromatics, mass %: NA
Aniline point, °C.: 74.2
Watson K-factor: 11.6
Cloud point, °C.: 4
Cold-filter plugging point, °C.: 8
Pour point, °C.: 3
Cetane no.: 56.2
Cetane index (D-976): 46.5
Calculated cetane index (D-4737): 55.4
Carbon residue (micromethod), mass %: <0.10
Kin. vis. at 20° C., cst: 21.4
Kin. vis. at 50° C., cst: 7.45
Kin. vis. at 100° C., cst: 2.49
Nitrogen, mg/kg: NA
Basic nitrogen, mass %: 0.005
Refractive index at 67° C.: 1.474
Distillation D-86 (50%), °C.: 336.5
375-420° C.
Yield on crude, mass %: 8.56
Yield on crude, vol %: 8.12
Density at 15° C., kg/l.: 0.9036
Specific gravity at 60/60° F.: 0.9041
API gravity at 60/60° F.: 25.0
Sulfur, mass %: 0.236
Total aid no., mg KOH/g: 1.00
Aniline point, °C.: 85.2
Watson K-factor: 11.7
Pour point, °C.: 24
Carbon residue (micromethod), mass %: <0.10
Kin. vis. at 50° C., cst: 21.3
Kin. vis. at 100° C., cst: 5.07
Vanadium, mg/kg: <0.1
Nickel, mg/kg: <0.1
Nitrogen, mg/kg: NA
Basic nitrogen, mass %: 0.013
Refractive index at 67° C.: 1.483
420-525° C.
Yield on crude, mass %: 15.85
Yield on crude, vol %: 14.83
Density at 15° C., kg/l.: 0.9165
Specific gravity at 60/60° F.: 0.9170
API gravity at 60/60° F.: 22.8
Sulfur, mass %: 0.299
Total acid no., mg KOH/g: 1.30
Aniline point, °C.: 92.4
Watson K-factor: 11.8
Pour point, °C.: 39
Carbon residue (micromethod), mass %: <0.10
Kin. vis. at 50° C., cst: 65.0
Kin. vis. at 100° C., cst: 10.4
Vanadium, mg/kg: <0.1
Nickel, mg/kg: <0.1
Nitrogen, mg/kg: NA
Basic nitrogen, mass %: 0.025
Refractive index at 67° C.: 1.490
375°+ C.
Yield on crude, mass %: 37.40
Yield on crude, vol %: 34.47
Density at 15° C., kg/l.: 0.9308
Specific gravity at 60/60° F.: 0.9313
API gravity at 60/60° F.: 20.4
Sulfur, mass %: 0.377
Total acid no., mg KOH/g: 1.10
Aniline point, °C.: 93.2
Watson K-factor: 11.7
Pour point, °C.: 39
Carbon residue (micromethod), mass %: 3.2
Asphaltenes, mass %: <0.50
n-Pentane insolubles, mass %: 0.9
Ash, mass %: 0.011
Kin. vis. at 50° C., cst: 159.2
Kin. vis. at 100° C., cst: 19.0
Vanadium, mg/kg: 1.3
Nickel, mg/kg: 1.6
Nitrogen, mg/kg: NA
Basic nitrogen, mass %: 0.055
Penetration at 25° C., mm: 0.1
Refractive index at 67° C.: 1.502
525°+ C.
Yield on crude, mass %: 12.99
Yield on crude, vol %: 11.51
Density at 15° C., kg/l.: 30.9678
Specific gravity at 60/60° F.: 0.9684
API gravity at 60/60° F.: 14.6
Sulfur, mass %: 0.547
Aniline point, °C.: 100.0
Watson K-factor: 11.8
Pour point, °C.: 36
Carbon residue (micromethod), mass %: 9.6
Asphaltenes, mass %: <0.50
n-Pentane insolubles, mass %: 2.9
Ash, mass %: 0.056
Kin. vis. at 80° C., cst: 584
Kin. vis. at 100° C., cst: 194
Vanadium, mg/kg: 3.9
Nickel, mg/kg: 4.6
Nitrogen, mg/kg: NA
Basic nitrogen, mass %: 0.116
Penetration at 25° C., mm: 290
Composition, mass %
Normal paraffins
Methane: <0.01
Ethane: 0.04
Propane: 0.21
Butane: 0.43
Pentane: 0.50
Hexane: 0.53
Heptane: 0.56
Octane: 0.67
Nonane: 0.57
Total n-paraffins: 3.50
C4 hydrocarbons
i-Butane: 0.20
C5 hydrocarbons
Isoparaffins
2,2-Dimethylpropane: <0.01
i-Pentane: 0.42
Total C5 i-paraffins: 0.42
Naphthenes
Cyclopentane: 0.11
C6 hydrocarbons
Isoparaffins
2,2-Dimethylbutane: 0.03
2,3-Dimethylbutane: 0.08
2-Methylpentane: 0.37
3-Methylpentane: 0.23
Total C6 i-paraffins: 0.71
Naphthenes
Methylcyclopentane (incl. 2,2-Dimethylpentane): 0.59
Cyclohexane: 1.00
Total C6 naphthenes: 1.59
Aromatics
Benzene: 0.29
C7 hydrocarbons
Isoparaffins
2,2,3-Trimethylbutane: <0.01
3,3-Dimethylpentane: 0.02
2,4-Dimethylpentane: 0.05
2-Methylhexane: 0.19
2,3-Dimethylpentane: 0.10
3-Methylhexane: 0.24
Total C7 i-paraffins: 0.60
Naphthenes
cis-1,3-Dimethylcyclopentane: 0.13
trans-1,3-Dimethylcyclopentane: 0.12
trans-1,2-Dimethylcyclopentane: 0.24
Methylcyclohexane: 1.88
Ethylcyclopentane: 0.09
1,1-Dimethylcyclopentane: 0.08
Total C7 naphthenes: 2.55
Aromatics
Toluene: 0.79
C8 hydrocarbons
Isoparaffins
2,2,4-Trimethylpentane: <0.01
2,5-Dimethylhexane: 0.04
2,4-Dimethylhexane: 0.06
3,4-Dimethylhexane: 0.02
3,3-Dimethylhexane: 0.02
2,3-Dimethylhexane (incl. naphthenic compound): 0.09
2-Methyl-3-ethylpentane: 0.01
2-Methylheptane: 0.21
4-Methylheptane: 0.08
3-Methylheptane: 0.13
2,3,4-Trimethylpentane: 0.01
Total C8 i-paraffins: 0.66
Naphthenes
1,1,3-Trimethylcyclopentane (incl. 2,2-Dimethylhexane): 0.09
trans, cis-1,2,4-Trimethylcyclopentane: 0.08
trans,cis-1,2,3-Trimethylcyclopentane: 0.08
trans-1,4-Dimethylcyclohexane: 0.16
1,1-Dimethylcyclohexane: 0.07
trans-1-Methyl-3-ethylcyclopentane: 0.03
cis-1-Methyl-3-ethylcyclopentane: 0.02
trans-1-Methyl-2-ethylcyclopentane: 0.07
trans-1,2-Dimethylcyclohexane: 0.20
2-Propylcyclopentane: 0.02
cis-1,2-Dimethylcyclohexane: 0.10
Ethylcyclohexane: 0.56
1-Propylcyclopentane: <0.01
cis,cis-1,2,4-Trimethylcyclopentane: <0.01
1-Methyl-1-ethylcyclopentane: 0.01
cis-1,3-Dimethylcyclohexane (incl. naphthenic compound): 0.41
Total C8 naphthenes: 1.90
Aromatics
Ethylbenzene: 0.22
m-Dimethylbenzene (m-xylene): 0.69
p-Dimethylbenzene (p-xylene): 0.27
o-Dimethylbenzene (o-Xylene): 0.27
Total C8 aromatics: 1.45
C9 hydrocarbons
Isoparaffins
3,5-Dimethylheptane: 0.12
4-Methyloctane: 0.08
2-Methyloctane: 0.10
3-Methyloctane: 0.12
2,3,4-Trimethylhexane: <0.01
Unidentified paraffin: 0.05
Total C9 i-paraffins: 0.47
Naphthenes
1,1,3-Trimethylcyclohexane: 0.14
1-Methyl-2-propylcyclopentane: 0.05
1-Methyl-3-ethylcyclohexane: 0.16
1-Methyl-4-ethylcyclohexane: 0.11
1,1,4-Trimethylcyclohexane: 0.08
Unidentified naphthenes: 0.04
Total C9 naphthenes: 0.58
Total identified: 15.84
Total unidentified: 0.15
Total C10+: 84.01
Editor's note: StatoilHydro'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 StatoilHydro accepts no responsibility for any errors that it may contain."
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