WEG, the global manufacturer of motor and drive technology, has developed bespoke variable speed drive systems, aiming to help with extraction from some of Oman’s older oil fields where the natural pressure is beginning to fade
As the extraction process becomes more difficult as fields become depleted, the technology aims to ensure maximum productivity from oil and gas fields.
Boosting extraction from depleting reserves is part of a US$33bn project which aims to enhance Oman’s hydrocarbon production capabilities and help the country broaden its economic base. It is expected that Oman will unlock about one trillion cu/m of natural gas in the next 25 years, representing a long term sustainable competitive feedstock for its petrochemical industry. In addition, the country is also planning to develop downstream industries such as the production of Ethylene Dichloride (EDC), Caustic Soda and other chemicals.
As part of this major effort, the PDO Saih Rawl Field Depletion Project, Phase 2, is set see US$550mn invested on developing a daily gas production capacity of 30 mcm, which will be fed to the existing Saih Rawl central processing facility. Extra compressors will be installed to increase the pressure so that gas continues to flow, enabling the field to feed the liquefied natural gas (LNG) industry while offering a back-up when other plants are shut down for maintenance.
As the electric motor-driven systems (EMDS) are the largest individual source of energy use, accounting for 45 per cent of the world’s electricity consumption, Indian company Larsen & Toubro decided to partner with WEG to equip the main gas compressor with an efficient drive system, which could endure the demanding applications.
To meet such needs, WEG has developed a bespoke solution comprising 48 30kW variable speed drives and motors and 32 15kW drives and motors, which will be supplied as systems and mounted in control cabinets, and also include a high capacity circuit breaker for emergency cut outs and a by-pass system for direct on line (DOL) starting.
WEG’s variable speed drive systems have been tested at its manufacturing facility in Brazil in the presence of inspectors from PDO and Larsen & Toubro to simulate the harsh environmental and operating conditions that may occur in the field. WEG is also conducting performance tests of the motors at the fan manufacturer’s plant in Korea and has organised training sessions for PDO staff in the Brazilian factory.
WEG has also provided Larsen & Toubro with the overloads, switchgear, relays and pushbuttons used within the drive cabinets, aiming to ensure component compatibility and trouble free system building and commissioning as well as efficient ordering and delivery.
Other elements in the cabinet include a control power transformer and auxiliary contactors and circuit breakers. Additionally, a door mounted control panel incorporates a backlit LCD keypad, while a redundant serial link (two channels Modbus-RTU over RS485) provides communication to the wider control system. Finally, the control cabinets include space heaters, which are essential to withstand the extreme temperature differentials between day and night in the Oman desert, which can cause potentially damaging condensation.
