GE Aviation

--DALLAS, Texas - Uprates performed on four LM2500 aeroderivative gas turbines have increased power capacity, improved heat rate and lowered life cycle costs, GE Marine & Industrial Engines (M&I) announced today at Power-Gen International '97. The four LM2500s operate on platforms offshore in the Gulf of Mexico.

The platforms are owned by Petroleos Mexicanos (PEMEX), the Mexican government-held oil/gas company. The four LM2500s are used for mechanical drive service as a motor for gas compression modules during oil production.

Throughout 1996 and 1997, the four PEMEX LM2500s were uprated from twin-shank to single-shank configurations. The uprates were done during a scheduled major overhaul and without impacting the overhaul timetable. The units first began commercial operation in the early- to mid-1980s.

PEMEX found that each uprate has paid for itself in just 50 days of oil production.

Uprate Kit Benefits

Benefits of the LM2500 uprate kits include:

• Power increase from 6% to 23% depending on operating conditions (engine rating increase from 27,500 shaft horsepower [shp] to 31,200 shp [20.5 megawatts to 23.3 megawatts] at ISO conditions);
• Improved heat rate from 1% to 7% depending on operating conditions;
• Lower incremental fuel costs derived from the 1.6% to 6.9% higher efficiency (2% at ISO standard day conditions);
• Lowered maintenance costs due to improved hot section life and repairability;
• Commonality with current production configuration; and
• State-of-the-art component improvements.

The LM2500 uprate kit includes a new high-pressure turbine (HPT) rotor assembly, as well as new stage 1 and 2 HPT nozzle assemblies.

If the uprate is performed on site, the kit will include rotable turbine mid-frame and combustor assemblies; if it is performed at the depot, the kit will include the necessary parts to uprate the turbine mid-frame and combustor.

All HPT blades and nozzles have the latest coatings to reduce oxidation and extend intervals between maintenance. These HPT blades and nozzles also have improved repairability, which may lower future maintenance costs because fewer new parts will be required. These enhancements enable the gas turbine to operate at a higher firing temperature resulting in higher power output and increased efficiency. Combined, these improvements also will allow the gas turbine blades and vanes to operate at both lower temperatures and lower stress levels.

The single-shank design achieved with the LM2500 uprate kit is required if converting to M&I's Dry Low Emissions or steam injected emissions abatement systems.

Uprates can be performed on site or off site at an authorized GE depot shop.

GE M&I is part of GE Aircraft Engines and is headquartered in Evendale. M&I is the world's largest designer, developer and manufacturer of aeroderivative gas turbines for a variety of power generation, gas compression and commercial and military marine propulsion applications.