Drive equipment and methods for mobile fracturing transportation platforms
Embodiments of drive equipment for mobile hydraulic fracturing power units and methods for changing and controlling the drive equipment are disclosed. The mobile power units include a gas turbine engine that provides mechanical power to drive shaft which is connected to the drive equipment such that the drive equipment is driven by the engine. The drive equipment may be a hydraulic fracturing pump or an electrical generator. The drive shaft is rotated at a speed suitable for the hydraulic fracturing pump and the electrical generator includes a step up gearbox to increase a rotational speed of the drive shaft for use by the electrical generator. The drive equipment may be secured to a skid that is field changeable with a crane or a fork lift to change the drive equipment at a well pad based on the demands of the well pad.
1. A mobile power unit having a transportation platform, the mobile power unit comprising:
a gas turbine engine mounted to the transportation platform and having an engine output shaft that rotates to provide energy from the gas turbine engine;
a drive shaft connected to the gas turbine engine on the transportation platform;
a reduction gearbox positioned on the transportation platform and disposed between the engine output shaft and the drive shaft, the reduction gearbox reducing a speed of rotation of the engine output shaft to a speed of rotation of the drive shaft, the reduction gearbox having a ratio in a range of 5:1 to 20:1; and
a drive equipment receiver including drive equipment connected to the drive shaft on the transportation platform, the drive equipment receiver having a first configuration when a pump is installed so as to define the drive equipment in the drive equipment receiver so that the pump is driven by the drive shaft attached to the gas turbine engine on the transportation platform, the pump being configured to provide high pressure fluid when driven by the gas turbine engine, the drive equipment receiver also having a second configuration when an electrical generator having a generator gearbox is installed so as to define the drive equipment in the drive equipment receiver so that the electrical generator is driven by the generator gearbox, which is driven by the drive shaft attached to the gas turbine engine on the transportation platform, the electrical generator configured to provide electrical power when driven by the gas turbine engine and configured so that the generator gearbox steps up a speed of rotation of the drive shaft, the generator gearbox at least partially offsetting the reduction gearbox.
2. The mobile power unit according to claim 1 , wherein the electrical generator is secured to a skid, the skid selectively securable to the drive equipment receiver so that the electrical generator is aligned with the drive shaft.
3. The mobile power unit according to claim 1 , wherein the generator gearbox having a ratio in a range of 1:1.25 to 1:5.
4. The mobile power unit according to claim 1 , wherein the electrical generator includes a permanent magnet alternator such that the electrical generator converts rotation of the drive shaft into electrical power.
5. The mobile power unit according to claim 4 , wherein the electrical generator includes a self-sufficient cooling system installed in the second configuration, the cooling system configured to circulate cooling fluid through the electrical generator.
6. The mobile power unit according to claim 4 , wherein the electrical generator includes a cooling system having a generator cooling pump configured to circulate a cooling fluid through the electrical generator, the generator cooling pump powered by a lubrication pump of the mobile power unit, the lubrication pump mounted to the transportation platform outside of the drive equipment receiver.
7. The mobile power unit according to claim 1 , wherein the pump and the electrical generator include lifting loops, the lifting loops configured to be engaged by a crane to lift the pump or the electrical generator from or into the drive equipment receiver such that the mobile power unit is field interchangeable between the first configuration and the second configuration.