All producers in SPD are equipped with electrical submersible pumps. With flow rates from 20 to 700 m3/d and a flowing bottom hole pressure (FBHP) between 60-65 bar, ESPs are optimally suited for the conditions in SPD’s fields.
Since ESPs are the main artificial lilt system used in Salym, serious attention is paid to installation and maintenance of the pumps and best practices are used to increase the life of ESPs.
SPD has tried many technologies to improve the service life, reliability and economic efficiency of ESPs. The application of Permanent Magnet Motors (PMM) is one of such attempts. In Russia, PMM technology is successfully employed in the oil fields of several Russian oil majors. SPD started pilot testing of ESPs with PMM in March 2007.
There are several drivers that make PMM attractive to use in comparison with conventional asynchronous motors: lower power consumption, much lower harmonic effects in electrical systems and a wider operational range. PMM do not create shock loads on the shaft because the PMM system also acts as a “soft start” providing higher system mechanical reliability.
Currently, ESPs account for more than 50% of the power consumption in the Salym fields. PMM has a demonstrated 20-30% lower power intake with the same mechanic power against asynchronous motors in Salym. The PMM ESP is more expensive than a standard ESP system but similar in price to an ESP fitted with a variable speed drive (VSD) system. The PMM does not require a VSD as its speed is already variable by design and will give significant life cycle power savings from the same capital expenditure.
During operations ESPs can fail due to a variety of reasons, the main reason being scaling on the ESP working parts (almost 40% of all failure cases). To combat this, SPD has employed a downhole chemical canister with a hard reagent, which is placed below the ESP. This canister is used for the metered supply of salting inhibitors into the formation fluid in order to stop the scaling and corrosion of the submersible equipment. Coating ESP rotating parts with Ryton polymer represents another efficient approach to preventing scale build-up.
All oil produced on the Salym group of fields is fed into the Russian Transneft oil pipeline system via the Custody Transfer Facility located near Sentyabrsky village. As it enters the Transneft oil pipeline via its South Balyk Booster Station, part of the Salym oil is forwarded to Europe for export, and part of it is sold by the company’s shareholders on the domestic market, predominantly to oil refineries in Moscow, Ufa, and Krasnoyarsk.
SPD Custody Transfer Facility is located outside the territory of the Salym group of fields to which it is connected by oil export pipelines. Construction of this 88 km long pipeline was completed in August 2005, 8 months after the West Salym field was brought onstream. Therefore, oil from the first Salym oilfield wells was transported by oil tank trucks.