Physicochemical Characteristics and Fractional Composition of Oil from the Samotlor Field
Abstract Generated abstract
This paper characterizes crude oil from the Samotlor field using standard physicochemical measurements and fractional distillation. The reported data show a relatively light, low-viscosity oil with modest sulfur, paraffin, resin, and asphaltene contents, a comparatively high pour point, and little change in pour point after heat treatment. Distillation by standard and detailed fractionation methods indicates a substantial yield of light fractions, with about half of the oil boiling below 300°C, and the fractional profile is compared with oils from the Nizhne-Vartovsk arch, especially Sovetskaya oil.
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PHYSICOCHEMICAL CHARACTERISTICS AND FRACTIONAL COMPOSITION OF OIL FROM THE SAMOTLOR FIELD
N. M. SMOLYANINOVA, S. I. SMOLYANINOV, L. E. ALEKSANDROVA,
V. K. ZHURBA, V. B. ORLOVSKY
(Presented by the scientific-methodological seminar of the CTF)
The physicochemical characteristics of Samotlor oil are given in Table 1.
The oil is characterized by a relatively low specific gravity \((d_4^{20} — 0.8525)\), a relatively low sulfur content \((0.95\%)\), resin-asphaltene substances (asphaltenes — \(1.07\%\), silica-gel resins — \(8.53\%\)) and paraffin \((3.74\%\), with a melting point of \(54^\circ\mathrm{C})\). The viscosity of the oil is low \((9.14\ \mathrm{cSt}\) at \(20^\circ\mathrm{C})\), the pour point is fairly high \((-9^\circ\mathrm{C})\), and changes little with heat treatment.
Table 1
Physicochemical characteristics of the oil (well 14, pl. A-1)
| Specific gravity, \(d_4^t\), at temperature, °C | Specific gravity, \(d_4^t\), at temperature, °C | Specific gravity, \(d_4^t\), at temperature, °C | Specific gravity, \(d_4^t\), at temperature, °C | Molecular weight | Kinematic viscosity, cSt, at temperature, °C | Kinematic viscosity, cSt, at temperature, °C | Kinematic viscosity, cSt, at temperature, °C | Kinematic viscosity, cSt, at temperature, °C | Flash point, °C | Pour point, °C | Pour point, °C | Saturated vapor pressure, mm Hg, at | Saturated vapor pressure, mm Hg, at |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 20 | 30 | 40 | 50 | 20 | 30 | 40 | 50 | with heat treatment | without treatment | 38°C | 50°C | ||
| 0.8525 | 0.8456 | 0.8386 | 0.8321 | 213 | 9.14 | 7.04 | 5.60 | 4.48 | —14 | —7 | —9 | 145 | 327 |
Continuation of Table 1
| Content, % | Content, % | Content, % | Content, % | Content, % | Content, % | Coking value, % | Acid number | Elemental composition, % | Elemental composition, % | Elemental composition, % | Elemental composition, % | Elemental composition, % |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| asphaltenes | silica-gel resins | sulfurous-acid resins | paraffin | naphthenic acids | phenols | C | H | O | N | S | ||
| 0.71 | 8.53 | 29.0 | 3.64 | 0.009 | 0.027 | 3.15 | 0.06 | 85.73 | 12.78 | 0.48 | 0.28 | 0.45 |
During distillation according to GOST 2177-59, Samotlor oil gives a considerable yield of light fractions: up to \(200^\circ\mathrm{C}\), \(28.8\%\) boils off; up to \(300^\circ\mathrm{C}\) — \(49.0\%\).
To characterize the fractional composition and the quality of the fractions, the oil was distilled into 10-degree and 3% (by volume) fractions on an ARN-2 apparatus. Table 2 and the figure present data on the potential content of fractions and the distillation curves of oil from the Samotlor field.
It should be noted that, in its properties, Samotlor oil is close to other oils of the Nizhne-Vartovsk arch — Megion oil and especially Sovetskaya oil.*
* New Oils of the Eastern Regions of the USSR, ed. S. N. Pavlova and Z. V. Driatskaya. Izd. “Khimiya,” Moscow, 1967.
Table 2
Potential content of fractions in oil from the Samotlor field
| Temperature limits for fraction collection, °C | Fraction yield, wt. % of oil, separately | Fraction yield, wt. % of oil, cumulative | Temperature limits for fraction collection, °C | Fraction yield, wt. % of oil, separately | Fraction yield, wt. % of oil, cumulative |
|---|---|---|---|---|---|
| Gas up to 28°C: | |||||
| a) ethane | 0,01 | 0,01 | 190—200 | 1,7 | 28,4 |
| b) propane | 0,44 | 0,45 | 200—210 | 1,9 | 30,5 |
| c) iso-butane | 0,35 | 0,80 | 210—220 | 2,0 | 32,5 |
| d) n-butane | 1,30 | 2,1 | 220—230 | 1,7 | 34,2 |
| 28—60 | 3,0 | 5,1 | 230—240 | 1,8 | 36,0 |
| 60—62 | 0,2 | 5,3 | 240—250 | 1,6 | 37,6 |
| 62—70 | 1,4 | 6,7 | 250—260 | 1,8 | 39,4 |
| 70—80 | 1,5 | 8,2 | 260—270 | 1,7 | 41,1 |
| 80—85 | 0,8 | 9,0 | 270—280 | 1,8 | 42,9 |
| 85—90 | 0,8 | 9,8 | 280—290 | 1,9 | 44,8 |
| 90—95 | 0,8 | 10,6 | 290—300 | 2,0 | 46,8 |
| 95—100 | 0,6 | 11,2 | 300—310 | 1,8 | 48,6 |
| 100—105 | 0,6 | 11,8 | 310—320 | 2,0 | 50,6 |
| 105—110 | 0,8 | 12,6 | 320—330 | 2,1 | 52,7 |
| 110—120 | 1,4 | 14,0 | 330—340 | 2,1 | 54,8 |
| 120—122 | 0,2 | 14,2 | 340—350 | 2,0 | 56,8 |
| 122—130 | 1,6 | 15,8 | 350—360 | 2,0 | 58,8 |
| 130—140 | 1,8 | 17,6 | 360—370 | 2,0 | 60,8 |
| 140—145 | 1,1 | 18,7 | 370—380 | 2,0 | 62,8 |
| 145—150 | 1,1 | 19,8 | 380—390 | 1,8 | 64,6 |
| 150—160 | 1,7 | 21,5 | 390—400 | 1,8 | 66,4 |
| 160—170 | 1,7 | 23,2 | 400—410 | 1,8 | 68,2 |
| 170—180 | 1,8 | 25,0 | 410—420 | 1,9 | 70,1 |
| 180—190 | 1,7 | 26,7 | 420—430 | 1,7 | 71,8 |
| 190—200 | 1,7 | 28,4 | 430—440 | 1,6 | 73,4 |
| residue | 26,6 | 100,0 |
Fig. 1. Distillation curves of Samotlor oil