Commercial qualities of gas condensates from the Luginetskoye and Severo-Vasyuganskoye fields of Tomsk Oblast
Abstract Generated abstract
This paper evaluates the commercial properties of gas condensates from the Luginetskoye and Severo-Vasyuganskoye fields in Tomsk Oblast through direct distillation and testing of gasoline, kerosene, jet fuel, and diesel fuel fractions. The study reports high yields of gasoline-range fractions, low or absent sulfur, modest neat octane numbers with strong response to tetraethyl lead, and middle distillate properties generally compatible with specified fuel grades after treatments such as alkaline purification, dewaxing, or depressant addition. The condensates are characterized as valuable feedstocks for light petroleum products, with potential yields of gasoline and jet fuel reported to be substantially higher than those from many conventional crude oils.
Full Text
Commercial Properties of Gas Condensates from the Luginetskoye and Severo-Vasyuganskoye Fields in Tomsk Region
K. K. STRAMKOVSKAYA, N. M. SMOLYANINOVA, Z. I. TEREBINKINA,
V. B. ORLOVSKII
(Presented by the scientific-methodological seminar of the Chemical Engineering Faculty)
To characterize the commercial properties of the products of direct distillation of gas condensates from the Luginetskoye and Severo-Vasyuganskoye fields, gasoline distillates were separated from them by rectification, as well as distillates that can serve as feedstock for obtaining jet fuels and kerosenes. Residues boiling above 150°C and above 200°C were tested as diesel fuels. The commercial properties of these condensates are presented in Tables 1 and 2.
The gasoline fractions are distinguished by high yields (distillation up to 200°C—78.2 and 78.3%, respectively). Gasolines from the Luginetskoye condensate are characterized by a complete absence of sulfur and by low octane numbers in the neat form (49–67). Gasolines from the condensate of the Severo-Vasyuganskoye field are low-sulfur and have higher octane numbers (55–72), owing to the greater presence in them of naphthenic hydrocarbons and iso-structure hydrocarbons. All gasolines have a high susceptibility to tetraethyl lead: when 0.82 g of TEL is added per 1 kg of fractions, their octane numbers increase by 14–17 points and amount to 66–83. An addition of 2.7 g of TEL per 1 kg of gasoline fractions causes an increase in their octane numbers to 88–82.
It is known that straight-run gasolines having octane-number values in the range 87–97 (at a content of 3.3 g TEL per 1 kg of fuel) are used as components of aviation gasolines. Thus, the gasoline fractions of the gas condensates studied meet the technical requirements for A-66 gasolines and can be used as components of aviation gasolines (with the addition of 3.3 g TEL per 1 kg of fuel).
Fractions 120–240 and 120–280°C of the condensates, according to all indicators except acidity and the temperature at the onset of crystallization, correspond to grade T-2 fuel (GOST 10227-62). Consequently, to obtain specification-grade jet fuel from them, only alkaline purification and dewaxing or the addition of a depressant are necessary. Fuels of grades T-1 and TS-1 cannot be produced from the indicated cuts, since the fractions have low densities and flash points.
From the gas condensate of the Severo-Vasyuganskoye field, 22.3% of illuminating kerosene meeting GOST 4755-49 can be obtained without additional purification. Such a product can also be obtained from the Luginetskoye condensate.
Table 1
Characteristics of products of direct distillation of Luginetskoye gas condensate
| Cut temperature, °C | Yield on crude oil, % | Density, $\rho^{20}_{4}$ | Viscosity, cSt, 20°C | Viscosity, cSt, 50°C | Viscosity, cSt, −40°C | Total sulfur content, % | Temperature, °C: solidification | Temperature, °C: flash in closed cup | Temperature, °C: initial crystallization | Cetane number | Octane number: neat | Octane number: with 0.822 g Pb per kg fuel | Acidity, mg KOH per 100 ml of fraction | Iodine number, g iodine per 100 g fuel | Coking tendency, % |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 28–87 | 26.7 | 0.6685 | — | — | — | — | — | — | — | — | 67.5 | 82.2 | 0.65 | — | — |
| 28–200 | 39.0 | 0.7280 | — | — | — | — | — | — | — | — | 62.0 | 74.0 | 0.60 | — | — |
| 28–150 | 63.6 | 0.7215 | — | — | — | — | — | — | — | — | 54.8 | 72.8 | 0.60 | — | — |
| 28–200 | 78.2 | 0.7280 | — | — | — | — | — | — | — | — | 48.6 | 66.1 | 0.61 | — | — |
| 120–240 | 34.5 | 0.7670 | 1.60 | — | — | — | — | — | −54 | — | — | — | 2.29 | 0.37 | — |
| 120–280 | 37.9 | 0.7695 | 1.70 | — | — | — | — | — | −46 | — | — | — | 2.50 | 0.87 | — |
| above 150 | 26.6 | 0.7893 | 1.99 | 1.27 | — | — | −49 | 52 | −20 | more than 56 | — | — | 1.04 | 0.45 | 0.02 |
| above 200 | 12.0 | 0.8065 | 2.82 | 1.68 | — | — | −32 | 82 | −14 | more than 56 | — | — | 6.28 | 0.55 | 0.02 |
Characteristics of products from direct distillation of gas condensate from the Severo-Vasyuganskoye field
Table 2
| Distillation temperature, °C | Yield on oil, % | Density, $\rho^{20}_{4}$ | Viscosity, cSt, 20°C | Viscosity, cSt, 50°C | Viscosity, cSt, −40°C | Sulfur content, % | Pour point, °C | Flash point in closed cup, °C | Cloud point, °C | Initial crystallization temperature, °C | Cetane number | Octane number, neat | Octane number with 0.82 g TEL per kg fuel | Acid number, mg KOH per 100 ml fraction | Iodine number, g iodine per 100 g fuel | Coking tendency, % |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 28–85 | 28.7 | 0.6630 | — | — | — | — | — | — | — | — | — | 72.4 | 82.8 | 0.41 | — | — |
| 28–120 | 53.8 | 0.7125 | — | — | — | — | — | — | — | — | — | 62.7 | 79.7 | 0.48 | — | — |
| 28–150 | 65.3 | 0.7245 | — | — | — | — | — | — | — | — | — | 60.7 | 76.6 | 0.50 | — | — |
| 28–200 | 78.3 | 0.7310 | — | — | — | 0.003 | — | — | — | — | — | 54.6 | 71.6 | 0.51 | — | — |
| Gasoline fractions | ||||||||||||||||
| 120–240 | 30.1 | 0.7660 | 1.15 | — | — | 4.56 | — | 34 | — | −58 | — | — | — | 0.51 | 0.53 | — |
| Fuel for jet engines | ||||||||||||||||
| 150–280 | 22.3 | 0.8360 | — | — | — | — | 0.01 | 50 | — | −38 | — | 35 | — | 0.83 | — | — |
| Above 150 | 24.8 | 0.7941 | 2.12 | 1.33 | — | 0.05 | −26 | 55 | — | −22 | above 56 | — | — | 2.43 | 0.64 | 0.03 |
| Above 200°C | 11.8 | 0.8103 | 3.74 | 2.05 | — | 0.10 | −18 | 76 | — | −12 | — | — | — | 3.75 | 1.41 | 0.05 |
| Kerosene distillates |
As diesel fuels, residues boiling above 150°C and above 200°C were investigated. As can be seen from the data presented (Tables 1, 2), they are characterized by high cetane numbers and meet the requirements for summer diesel fuel according to GOST 305-62. These residues also, by all indicators (with the exception of freezing and cloud points), comply with the technical specifications for winter diesel fuel and, apparently, after dewaxing can be used as such.
It follows from the foregoing that the gas condensates of the Luginetskoye and Severo-Vasyuganskoye fields are a very valuable raw material for obtaining light commercial petroleum products. From them, gasolines and jet fuels can be obtained in quantities 2–3 times greater than from most oils of the Soviet Union.
Conclusions
-
The commercial properties of the gas condensates of the Luginetskoye and Severo-Vasyuganskoye fields have been investigated.
-
It has been shown that gas condensates can yield A-66 grade gasoline components and jet fuels of grades T-1, T-2, and TS-1, with yields 2–3 times greater than those from many oils of the Soviet Union.
-
From the condensates obtained, illuminating kerosene and diesel fuels can be produced.