System for pumping hydraulic fracturing fluid using electric pumps
View Patent ↗A system for hydraulically fracturing an underground formation in an oil or gas well to extract oil or gas from the formation, the oil or gas well having a wellbore that permits passage of fluid from the wellbore into the formation. The system includes a plurality of pumps powered by electric induction motors and fluidly connected to the well, the pumps configured to pump fluid into the wellbore at high pressure so that the fluid passes from the wellbore into the, and fractures the formation. The system can also include a plurality of natural gas powered generators electrically connected to the plurality of pumps to provide electrical power to the pumps.
1. A system for hydraulically fracturing an underground formation in an oil or gas well to extract oil or gas from the formation, the oil or gas well having a wellbore that permits passage of fluid from the wellbore into the formation, the system comprising;
a plurality of pumps mounted on a trailer or truck and powered by electric motors and fluidly connected to the well, the pumps configured to pump fluid into the wellbore at high pressure so that the fluid passes from the wellbore into the formation, and fractures the formation;
at least one variable frequency drive connected to the electric motors to control the speed of the motors, the at least one variable frequency drive frequently performing electric motor diagnostics to prevent damage to the electric motors if they become grounded or shorted; and
a plurality of generators electrically connected to the plurality of pumps to provide electrical power to the pumps.
2. The system of claim 1 , wherein at least some of the plurality of generators are powered by a fuel selected from the group consisting of natural gas, liquefied natural gas, and diesel.
3. The system of claim 1 , wherein at least some of the plurality of generators are turbine generators.
4. The system of claim 1 , further comprising:
an A/C console.
5. The system of claim 1 , wherein the plurality of pumps are mounted on a trailer, and can be ported from one well to another.
6. The system of claim 1 , wherein the generators are mounted on the trailer or truck, and can be ported from one well to another.
7. The system of claim 1 , further comprising a plurality of variable frequency drives attached to the plurality of pumps, wherein each variable frequency drive discretely controls a single pump.
8. A system for fracturing a rock formation in an oil or gas well by pumping hydraulic fracturing fluid into the well, the system comprising:
a pump for pumping the hydraulic fracturing fluid into the well, and then from the well into the formation, the pump mounted on a trailer or truck and capable of pumping the hydraulic fracturing fluid at high pressure to crack the formation;
an electric motor having a high-strength steel or steel alloy drive shaft attached to the pump and configured to drive the pump;
a variable frequency drive connected to the electric motor to control the speed of the motor, the variable frequency drive frequently performing electric motor diagnostics to prevent damage to the electric motor if it becomes grounded or shorted; and
a generator connected to the electric motor that provides electric power to the electric motor.
9. The system of claim 8 , wherein the pump is a triplex or a quintuplex pump rated at about 2250 horsepower or more.
10. The system of claim 9 , wherein the pump has 4.5 inch diameter plungers with an eight inch stroke.
11. The system of claim 8 , wherein the electric motor has a maximum continuous power output of about 1500 horsepower or more.
12. The system of claim 11 , wherein the electric motor has a maximum continuous torque of about 8750 ft-lb or more.
13. The system of claim 12 , wherein the electric motor has a high temperature rating of about 1100 degrees C. or more.
14. The system of claim 13 , wherein the drive shaft of the electric motor is composed of 4340 alloy steel.
15. The system of claim 8 , wherein the generator is a turbine generator.
16. The system of claim 8 , wherein the variable frequency drive includes power semiconductor heat sinks having one or more thermal sensors monitored by a microprocessor to prevent semiconductor damage caused by excessive heat.
17. The system of claim 8 , wherein the variable frequency drive is mounted to the trailer or truck.
18. The system of claim 8 , wherein the trailer has three axles.
19. The system of claim 18 , wherein the motor is attached to the trailer, and the trailer has cross-members that support the torque of the motor.
20. The system of claim 18 , wherein the trailer has a neck that includes a strengthening outer rib.
21. The system of claim 18 , wherein the trailer has mounts attaching the variable frequency drive to the trailer, the mounts composed of a material that allows the trailer to move independently of the variable frequency drive to reduce vibration of the variable frequency drive.
22. A system for hydraulically fracturing an underground formation in an oil or gas well to extract oil or gas from the formation, the oil or gas well having a wellbore that permits passage of fluid from the wellbore into the formation, the system comprising:
a trailer;
two or more pumps attached to the trailer without a skid and fluidly connected to the well, the pumps configured to pump fluid into the wellbore at high pressure so that the fluid passes from the wellbore into the formation, and fractures the formation;
one or more electric motors attached to the pumps to drive the pumps, the electric motors attached to the trailer without a skid;
at least one variable frequency drive connected to the one or more electric motors to control the speed of the motors, the at least one variable frequency drive frequently performing electric motor diagnostics to prevent damage to the electric motors if they become grounded or shorted; and
a generator for connection to the one or more electric motors that provides electric power to the one or more electric motors.