During the June 2006 Oil & Gas Technology Conference, held in GE Aviation’s Evendale, Ohio, plant, oil and gas industry customers were given a unique opportunity to learn more about GE aeroderivative technology through interactive presentations and facility tours.
We were proud to take this opportunity to showcase our latest achievements in aeroderivative technology, demonstrating for our customers not only how the machines are built, but how they operate in simulated oil and gas applications.

The LM6000 industrial aeroderivative gas turbine is derived from GE Aviation’s CF6 aircraft engine – proven in over 120 million flight hours with a 99.97% departure reliability. To date we have installed more than 700 LM6000 gas turbines and recorded more than 10 million firing hours with this machine.

Exceptional power and efficiency

The LM6000 is a leader in low emissions and the first of the LM family to introduce DLE, dual-fuel DLE and 15 ppm NOx DLE. The LM6000 provides several alternate high efficiency configurations in the 40-50 MW range, for both power generation and mechanical drive applications. And, most important for oil and gas applications, it demonstrates exceptional power and efficiency over a wide range of operating speeds, as proven by extensive testing.

One purpose of our rigorous testing program is to qualify the LM6000 to ABS (Amercan Bureau of Shipping) endurance requirements for marine propulsion applications. This testing requires a 1,000 hour endurance test that includes 500 hours (68 cycles) in the power generation mode – this testing has been completed at our Houston, Texas, facility. A second part of the endurance testing includes 500 hours (68 cycles) in the mechanical drive mode – this testing is ongoing in Evendale, Ohio.

The second purpose for the testing is to validate various mechanical drive objectives for the LM6000. These objectives include:

• Validation of the air/oil sump evacuation system for low speed/low pressure operation
• Demonstration of low speed (<1600 r/min) operation
• Testing the machine’s core software
• Proving of generator mechanical load control
• Ensuring the units meets NOx emission requirements using water suppression

Testing also included operating the unit from 800 to 3,600 r/min (22 to 100% speed) along a full-pressurized LNG torque/speed  curve – on gas fuel without NOx suppression. During these tests, the LM6000 demonstrated its ability to start-up a full pressurized LNG compression train from standstill condition, with no need for a starter/helper motor to be installed. 

The operability test objectives were achieved without any problems and the machine is now released for unrestricted operation in the range from 1,800 rpm to 3,780 rpm (50-105%) and loads varying from 0% (idle) to 100% (44.7 MW @ISO day).

Engine exchange

With oil and gas production sites often located in remote areas or offshore, the advantages of the aeroderivative engines come into play because of their unique off-shore and engine-exchange capabilities. The LM6000 allows large pitch and roll angles and, in case of planned or unplanned maintenance, can be exchanged on-site in just 24 hours. The new engine is brought quickly into production while the replaced engine is sent to a maintenance facility.

Fewer units, lower fuel consumption

For plants that require large amounts of total power, the LM6000 offers advantages in both initial investment and operating costs. Thanks to its higher power and efficiency, the LM6000 means fewer installed units and lower overall fuel consumption. Another benefit of the LM6000 compared to heavy-duty gas turbines is the engine-exchange feature. As an example of the productivity gain, for LNG production applications the engine-exchange feature is estimated to give an availability step-up from 95% to 97%, thus gaining 7 production days per year and $20M in additional annual revenues.

Each cycle is approximately eight hours at variable speeds along a 36.6 MW cubic and the tests are corrected to reflect a dry 100°F (37.8°C) “Navy Day”.

Prior to the start of the ABS endurance test, GE’s engineering team developed several facility/control modifications to support the LM6000 as a mechanical drive unit.The test cell generator was modified to simulate a mechanical load, a combined low-speed sump evacuation system/single-stage air oil separator system was designed and successfully operated, and modifications to the facility’s Mark VI software were all significant developments in support of the ABS endurance test.

Improved operability

Key to meeting the mechanical drive objectives of the ABS endurance test was demonstrating the LM6000’s ability to provide power at speeds from 800 to 3,600 r/min (22 to 100% speed) along a cubic power curve. This ability was demonstrated prior to the endurance test by optimizing the variable geometry for improved operability –operating successfully at speeds below 1,600 r/min- operating across the speed range with either gas or distillate fuels (with and without water NOx suppression), and completing fast (<45 second) minimum to maximum speed changes along a cubic load curve.

The operability test objectives were achieved without issues and even exceeded the power target. According to Tayo Montgomery, technical sales support manager for GE Aircraft Engines. “Our oil and gas customers are growing their capacity and therefore trying to find ways to produce petroleum products at a lower cost. One of the ways they can accomplish this is by increasing their economies of scale, thus the interest in the larger LM6000”.

“As a result of these tests, the LM6000 demonstrated its capability to start up a fully pressurized LNG compression train from standstill condition, without the need for a starter/helper motor. The LM6000 is a capable mechanical drive machine, demonstrating very good speed flexibility at constant power.”

The GE Oil &Gas LM6000 fleet includes 15 units with >290,000 running hours, in service on FPSO and power barges.

For more information, please contact:

Francesco Trincia
francesco.trincia@ge.com