ECONOMICS

GROWTH OF THE P E T R O C H E M I C A L I N D U S T R Y

IN WESTERN SIBERIA

Yu. I. B o k s e r m a n

Western Siberia is the largest base of the oil and gas industry in the nation. With respect to reserves of already discovered oil and gas fields and the promise of its natural resources, the West-Siberian oil-bearing province has no equal; the potential oil reserves of this province (with water areas), according to the data of the scientific-research institute "ZapsibNIIGNI," are estimated in billions of metric tons. Hence, there is full justification for the high rates of development of large oil and gas fields of Western Siberia that are provided in the ninth five-year plan. For ex- ample, oil production must reach 125 million metric tons in 1975, and gas production (natural and associated) more than 40 billion m 3. The rapid growth in production of oil, natural and oil-associated gas, and gas condensate will make it feasible to create a reliable and extremely effective raw material base for the organization of petrochem- ical production in this area. The directives of the 24th Congress of the KPSS [Communist Party of the Soviet Union] have stipulated the start of construction of large petrochemical complexes in Tobol'sk and Tomsk.

In connection with the special importance of setting up petrochemical complexes in Western Siberia, in 1971 the State Expert Commission of Gosplan SSSR [State Planning Committee of the USSR], with the cooperation of a large group of scientists, carried out a c~tical analysis of the technicoeconomic bases for the construction of the Tobol'sk and Tomsk petrochemical complexes that had been developed by the design organizations of Minneftekhim- prom and Minkhimprom SSSR [Ministry of the Petrochemical Industry and Ministry of the Chemical Industry of the USSR]. In the course of the commission's work, a large group of specialists journeyed to the Tyumen and Tomsk re- gions to study the current situation in exploration and development of oil and condensate fields, the construction of gas processing plants, and problems of power and water supply, the sitting of housing developments, and the avail- ability of construction organizations and a base for the construction industry.

Major attention was given to the selection of a raw material base for the petrochemical complexes.

In the technoeconomic design basis that was presented for the critical analysis, it was envisaged that the feed- stocks for these petrochemical complexes would be products from crude oil stabilization produced in central crude- stabilizing plants built in conjunction with the complexes, operated for maximum yield of C 3- C~ hydrocarbons. Here it was planned that the unstabilized natural gasoline obtained from the by-product gases in gas processing plants would be pumped into the crude; it was also planned to use the gas condensate that is produced together with crude oil in the fields of the Tomsk region. After partial stabilization, the condensate in the oil fields would be pumped into the Aleksandrovskoe-Anzhero-Sudzhensk pipeline for common transport with the crude oil to the areas of consumption.

The State Expert Commission did not agree with these assumptions, rather adopting a resolution to use as hy- drocarbon feedstock the products obtained by processing oil-associated gas. The unit costs per metric ton of feed- stock will be reduced by a factor of 1.5-2 in comparison with those involved in the construction of special crude stabilization plants.

Oil-associated gases are an important source of hydrocarbon raw material; these gas resources in the Soviet Union as a whole will increase by some 80% from 1970 to 1975. Despite such a significant growth in the production of these gases, their utilization is thus far unsatisfactory. The main reason for this situation is the lag in construc- tion of gas processing plants, compressor stations, collection points, and gas pipelines in the oil fields. Rational utilization of associated gas can be ensured only by a joint solution of all problems related to gas collection, proces- sing, and transport of the dry gas to the consumers.

Translated from Khimiya i Tekhnolo~ya Top]iv i Masel, No. 11, pp. 39-42, November, 1972.

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In current oil-field practice, including that in Western Siberia, a single-pipe system is being introduced, in which the gas produced from the earth is transported together with the crude oil to central points for crude oil pre- treatment. This permits significant savings of equipment and metal and hastens the solution of the problem of asso- ciated gas collection. Under the conditions of Western Siberia, separation of the crude oil is accomplished in three stages: the first at a pressure of 4-6 kg/crn 2, the second at 2.5 kg/cm 2, and the third at 1.05 kg/crn 2. For calcula- tions of the quantity of gas being processed in a three-stage System, the data of the institutes "Giprotyurnenneftegaz" and "Giprovostokneft" were adopted, and account was also taken of gas factors that, for the principal oil deposits of Western Siberia, amount to 32 to 87 m ~ per metric ton of crude produced. The high content of C~-C5 hydrocarbons in the associated gas predetermines its utilization as feedstock for the petrochemical complexes of the Tyumen and Tomsk regions. This is the specific reason why processes of gasoline recovery from associated gas in natural gasoline plants must be developed and expanded at a higher rate in the ninth Five-Year Plan.

The volume of associated gas processing in the current Five-Year Plan is being more than doubled, which will require the addition of new production capacity.

Considering the large volume of construction of gas-processing plants in the oil districts of Western Siberia, it is impossible to repeat the errors allowed in the past in developing oil and gas fields, when the construction of gas processing plants was delayed, leading to considerable losses of gas and the valuable hydrocarbon fractions contained in the gas.

In 1971-1975, three gas-processing plants must be built in the Tyumen region. When these plants go into ser- vice, gasoline recovery will be possible for almost all of the associated gas that will be produced in 1975. The pe- riod 1976-1980 will see further growth in oil production and hence in associated gas. New plants will need to be built to process these materials.

It is contemplated that the flow plans used in the construction of the gas processing plants will be those that will maximize the recovery of heavy hydrocarbons from the gas. Considering the fact that the Tobol'sk and Tomsk petrochemical complexes are located close to the oil fields, it will be advisable to produce a wide hydrocarbon frac- tion in the gas processing plants and send this via pipeline to the indicated petrochemical complexes.

As previously noted, the West Siberian oil and gas province is unique in the extent of the land area showing promise and in the large number of already discovered fields. It is subdivided into 12 oil and gas districts, of which the Middle Ob, the Nadym-Pur, and the pur-Taz account for most of the potential crude oil reserves. Discovered oil reserves in the high categories (A + 13 + CO are in two districts, Nizhnebartovskoe and Surgut, where operations are also planned in gas collection and processing.

These districts are characterized by a high concentration of oil reserves and verylarge fields(for example, Samotlor). According to calculations of the institute "Giprotyumenneftegaz," in the period up to 1980 most of the oil and associated gas production will come from the deposits of the Nizhnevartovsk regio n.

In obtaining hydrocarbon feedstock from oil and associated gas, it is of primary importance to have data on the composition of the in-place and degassed crudes of the Nizhnevartovsk, Surgut, and Shaim districts

The available material on the separation and pretreatment of crude oil (at +40*C) indicates that the light hy- drocarbons pass into the gas in the following amounts (in % of the potential) :

C a . . . . . . . . . . . . 62 n'-C4 . . . . . . . . . . . 36 iso--C a . . . . . . . . . . 28 n-C~ . . . . . . . . . . . 11 zSo--c5 . . . . . . . . . . 7 C3--C 5 . . . . . . . . . . 31

These data have been used to calculate the hydrocarbon raw material resources that can be obtained from the associated gases in the oil fields of the Middle Ob and the northern regions of Western Siberia, for various oil pro- duction volumes, with a pretreatment temperature of+ 40"C.

The calculations showed that increasing the pretreatment temperature from 40 to 70~ very nearly doubles the

amount of butanes and pentanes in the by-product gas.

Proposals have been made for organizing a centralized pretreatment of crude oil at a temperature of + 70~ in units already available in gas processing plants. Such pretreatment will reduce the vapor pressure of crude oil for

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transport in overland pipelines and will curtail the losses of light fractions in refineries, where the terminals are still not equipped for receiving crudes with high vapor pressure. These problems are currently being worked out in sci- entific- research and design institutes.

Foreign experience confirms the need for maximum utilization of the hydrocarbon raw material contained in petroleum and associated gases. For example, in the USA, ethane and propane produced in gas-processing plants are the main source of hydrocarbon feedstock for ethylene production; this is explained by the relatively low cost of ethane, the high conversion of ethane to ethylene (up to 75%o), the lower capital costs in comparison with that for pyrolysis of liquid feedstocks, and the lower cost of the process equipment. Approximately 50% of the existing USA capacity for ethylene production uses ethane as the pyrolysis feedstock; ethane plus propane account for 85% of t h e total. These products are expected to retain their dominant position as feedstocks for production of the lower olefins.

In recent years, such components of by-product gases as butanes and pentanes have become very important in the growth of organic synthesis processes; these hydrocarbons are the base for the production of the most important monomers for various types of synthetic rubber. Such production will be organized on a large scale in Western Siberia, in view of the availability of significant resources of butanes and pentanes in the off-associated gases.

The petrochemical industry is using ever-increasing amounts of n-butane in the production of butadiene at a cost that is lower by a factor of 2-2.5 than (for example) the cost of butadiene produced from ethanol.

Another good feedstock for the petrochemical and chemical industries of Western Siberia may be the gas con- densates of the deposits in the Tomsk and Tyumen regions. Information from the Tyumen Central Geological Office confirms the availability of large reserves of condensate in the Urengoi gas-condensate field, located in the territory of the Yamalo-Nenetskii National Okrug [District] at a distance of about 6g0-700 km from the city of Nizhnevartov- skii, where the main gas processing plants are located.

Exploratory well drilling in the Urengoi field has indicated great promise for the lower Cretaceous deposits, which showed rich gas-condensate pools (at depths from 2300 to 3000 m).

Considering the availability of enormous resources of condensate in Western Siberia and the great promise for discovery of new fields, directions for its use as raw rnaterial in the petrochemical and chemical industries must be worked out in advance.

Thus, Western Siberia has at its disposal major resources of hydrocarbon raw material that will provide a re- liable base for the growth of petrochemistry and will also ensure the supply of hydrocarbon raw material to the European part of the nation.

In determining the composition of the petrochemical complexes of Western Siberia, the following basic as- sumptions were taken into account:

1. The creation of these complexes must meet the goal of improvement of the territorial placement of pro- duction capacity of the petrochemical and chemical industries, at least in the next 10-15 years.

2. The West Siberian petrochemical complexes must include large-tonnage, energy-consuming production of the most important synthetic materials, taking into account the need for providing complex processing of the initial oil-gas raw material.

It is contemplated that the petrochemical complexes will include large-scale production of synthetic rubbers for general use - isoprene, butadiene, and ethylene-propylene types.

On the basis of processing those components of the oil-gas raw material that cannot be used in synthetic rubber production, the petrochemical complexes should include organic synthesis plants for the production of petrochemical products and intermediates such as ethylene, propylene, lower and higher alcohols, benzene, styrene, polystyrene, polyester resins, etc.

In the construction of the petrochemical complexes, the priorities and staging of introduction of capacity must be strictly maintained.

It is quite evident that the achievements of science and engineering must find a wide reflection in the designs for the construction of the Siberian petrochemical complexes. In particular, wide use must be made of large-scale equipment and units, the newest process technology, and automation of production and control.

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For the conditions of h/estem S/bet'/a, with a shortage of labor, the use of high-productivity processes with large, automated units and equipment is of prime importance.

The creation of large petrochemical complexes in Western Siberia will require the urgent solution of problems in expanding the construction base and the construction industry, power, transport, etc. The fact is that the current volume of construction and installation work in the Tyumen region, for example, exceeds 700 million runes per year. However, with each year the targets become higher for growth of the key industries; therefore, in districts where petrochemical complexes are being built, there must be created as rapidly as possible strong bases for indus- trial and housing construction. Well-built, large housing developments must be provided for the construction workers and operators of the petrochemical complexes. In order to decrease the weight of the buildings and to expedite their erection, major use must be made of light-weight construction. To provide electric power, steam, and heat for the petrochemical complexes, large power stations must be built; the fuel for these stations in the Tomsk region can be low-cost coal of the Kansk-Achinsk district, located about 400 km from the city of Tomsk, and in the Tyumen re- gion the fuel can be gasoline-free by-product gas. In this connection, it is advisable to direct the gas from the gas- processing plants to the Surgut district for a power station and other consumers, to Tobol'sk for the petrochemical complex and a power station, and the excess gas to Tyumen, where there are major needs for city gas and for gas conversion of the Tyumen power plant.

The resolution of the 24th Congress of the CPSU on the construction of petrochemical complexes in the Tyumen and Tomsk regions has an enormous significance for the national economy; hence, the workers of the petroleum and gas industry are doing everything possible to bring this resolution into life.

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