LOW TEMPERATURE TURBOEXPANDERS (NTDA)

Application of automated complex gas treatment plants with the use of turboexpanders in the technology of gas treatment at gas condensate fields is an essential factor of increase of fields’ technical level.

NTDA are intended for obtaining of deep cold in installations of natural gas preparation and processing, providing temperature difference to 55 °С. According to the temperature at outlet from the unit, turbine expanders can be used:
- for natural gas cooling (minus 2 °С)
- for extraction of C5+ fraction (to minus 30 °С)
- for obtaining of propane-butane fraction (to minus 80 °С)
Depending on the composition of natural gas usage of NTDA allows extracting target components, including:

• methane fraction;
• ethane fraction;
• propane-butane fraction;
• broad fraction of light hydrocarbons;
• stable natural gasoline;
• normal-butane;
• isobutane
• isopentane;
• normal-pentane;
• pentan- hexane fraction.

At «Turbogaz» JSC are developed and manufactured turboexpanders with productivity from 0.5 to 10.0 mln. m3/day at gas pressure to 13.0 МPа, calculated for a wide range of gas composites (including sour) and works at fields with condensate factor to 100 gr/nm3.

We operatively perform adjustment of characteristics of the unit at mix of streams from different fields, which have different composition and thermobaric characteristics.

At development of each new structure are used recent developments of science and techniques, state-of-the-art technologies and new materials, which let reliably operate in any climatic conditions from arctic to south latitudes. Thus in the structure of turboexpanders with participation of S2M French company (magnetic bearings and high speed motors) was applied magnetic suspend of rotor, that allowed to resign from the system of lubrication of bearings.

Results of industry operation confirm effectiveness of use of turboexpanders, as well as opportunity of their application for preparation of natural gas, at gas condensate fields with different gas condensate characteristics at different levels of operation, in particular at stage of declining production.

All types of industry turboexpanders depending on their purpose operate with defined temperature fall on cooled gas stream. This parameter is determinative at design, «Turbogaz» JSC develops and manufactures units individually at specifically set-up parameters of this or that technology taking into account climatic conditions of operation.

Advantages of turboexpanders technology

• High profitability. Application of low temperature turboexpanders allows increasing 3-4 times operation temperature fall at field in comparison with throttling and increase condensate output from gas in average in 2-3 times. Due to supplementary output of propane-butane and stable condensate the payback period of units reduces to one year.
• Energy saving and ecology. Technology of low temperature separation with use of turbine expanders – energy saving technological process, without consumption of external sources of energy, in comparison with alternative variants of development of gas condensate fields: ammoniac and propane vapor-compressor refrigeration machines or absorbent refrigeration units.
• Durability of operation. Turbine expanders are applicable during the whole period of development of gas condensate fields, providing sufficiently larger drop of temperatures compared to the nozzle-effect with the drop of the wellhead pressure in the process of field exhaust.