Apparatus and methods for delivering a high volume of fluid into an underground well bore from a mobile pumping unit

1. A mobile hydraulic fracturing fluid delivery system for pumping high pressure fracturing fluid into an underground well bore at a well site and being transportable between multiple well sites, the mobile hydraulic fracturing fluid delivery system comprising:

a chassis, said chassis being configured to be transportable between well sites;

an electric motor disposed upon said chassis, said electric motor being electrically coupled to an external electric power source and having first and second opposing ends, said electric motor further having a single drive shaft extending axially therethrough and outwardly therefrom at said first and second opposing ends thereof;

a first fluid pump disposed upon said chassis, coupled directly to said drive shaft of said electric motor at said first end of said motor and configured to pump fracturing fluid into the well bore;

a second fluid pump disposed upon said chassis, coupled directly to said drive shaft of said electric motor at said second end of said motor and configured to pump fracturing fluid into the well bore at the same time as said first fluid pump,

wherein said first and second fluid pumps are axially aligned with said electric motor at said opposing ends thereof, further wherein said drive shaft of said electric motor is coupled to said first and second fluid pumps so that said electric motor is capable of concurrently driving both said fluid pumps;

at least a first flex coupling engaged with and between said electric motor and said first fluid pump and configured to allow movement of said electric motor and said first fluid pump relative to one another during and without disturbing the operation thereof; and

at least a second flex coupling engaged with and between said electric motor and said second fluid pump and configured to allow movement of said electric motor and said second fluid pump relative to one another during and without disturbing the operation thereof.

2. The mobile hydraulic fracturing fluid delivery system of claim 1 wherein said electric motor is configured to drive each said fluid pump regardless of the operation of said other fluid pump.

3. The mobile hydraulic fracturing fluid delivery system of claim 1 wherein said electric motor has a power rating of 6,000 hp and each of said first and second fluid pumps has a power rating of 3,000 hp.

4. The mobile hydraulic fracturing fluid delivery system of claim 1 wherein said first and second fluid pumps are coupled to said drive shaft of said electric motor out of phase.

5. The mobile hydraulic fracturing fluid delivery system of claim 1 further including first and second said electric motors and first and second sets of said first and second fluid pumps disposed upon said chassis, wherein said second electric motor is stacked atop said first electric motor and said first and second fluid pumps of said second set are stacked atop said first and second fluid pumps of said first set, respectively.

6. The mobile hydraulic fracturing fluid delivery system of claim 1 further including a remotely controllable variable frequency drive disposed upon said chassis and electrically coupled to said electric motor, said variable frequency drive configured to control the speed of said electric motor.

7. The mobile hydraulic fracturing fluid delivery system of claim 6 wherein said variable frequency drive is configured to be electrically coupled to said external electric power source and provide electric power to said electric motor when said external electric power source is disposed at a remote location relative to said chassis.

8. The mobile hydraulic fracturing fluid delivery system of claim 7 wherein said external electric power source is one among a local utility power grid and a gas turbine generator.

9. The mobile hydraulic fracturing fluid delivery system of claim 6 further including at least one busbar disposed upon said chassis and engaged with, and configured to electrically connect, said variable frequency drive and said electric motor.

10. The mobile hydraulic fracturing fluid delivery system of claim 6 wherein said electric motor is an AC permanent magnet motor having a power rating of 5,000 hp.

11. The mobile hydraulic fracturing fluid delivery system of claim 10 wherein each fluid pump is a high horsepower plunger-style fluid pump having a power rating of 2,500 hp.

12. The mobile hydraulic fracturing fluid delivery system of claim 6 wherein said chassis is mounted upon one among a trailer and a skid.

13. A mobile high pressure fluid pumping unit for pumping high pressure fluid into an underground well bore at a well site and being transportable between multiple well sites, the mobile high pressure fluid pumping unit comprising:

a chassis, said chassis being configured to be transportable between well sites;

first and second fluid pump disposed upon said chassis and configured to pump pressurized fluid into the well bore at the same time;

an electric motor disposed upon said chassis, having first and second opposing ends, a single drive shaft extending axially therethrough and outwardly therefrom at said first and second opposing ends thereof and being configured to concurrently drive both said first and second fluid pumps, said first fluid pump being coupled directly to said drive shaft of said electric motor at said first end of said electric motor and said second fluid pump being coupled directly to said drive shaft of said electric motor at said second end of said electric motor;

at least a first high horsepower elastic coupling engaged with and between said electric motor and said first fluid pump and configured to allow movement of said electric motor and said first fluid pump relative to one another during and without disturbing the operation thereof;

at least a second high horsepower elastic coupling engaged with and between said electric motor and said second fluid pump and configured to allow movement of said electric motor and said second fluid pump relative to one another during and without disturbing the operation thereof; and

a remotely controllable variable frequency drive disposed upon said chassis and electrically coupled to said electric motor and an external electric power source, said variable frequency drive being configured to provide electric power to said electric motor from said external electric power source and allow the speed of said electric motor to be remotely controlled.

14. The mobile high pressure fluid pumping unit of claim 13 further including at least one busbar disposed upon said chassis and engaged with, and configured to electrically connect, said variable frequency drive and said electric motor.

15. The mobile high pressure fluid pumping unit of claim 13 wherein said electric motor is configured to drive each said fluid pump regardless of the operation of said other fluid pump.

16. The mobile high pressure fluid pumping unit of claim 13 wherein said first and second fluid pumps are desynchronized.

17. The mobile high pressure fluid pumping unit of claim 13 further including first and second said electric motors and first and second sets of said first and second fluid pumps disposed upon said chassis, wherein said second electric motor is stacked atop said first electric motor and said first and second fluid pumps of said second set are stacked atop said first and second fluid pumps of said first set, respectively.

18. Apparatus for pumping high pressure fluid into an underground well bore at a well site and being transportable between multiple well sites, the apparatus comprising:

a mobile chassis, said chassis being configured to be transportable between well sites;

an electric motor disposed upon said chassis, said electric motor being electrically coupled to an external electric power source and having first and second opposing ends, said electric motor further having a single drive shaft extending axially therethrough and outwardly therefrom at said first and second opposing ends thereof;

a first fluid pump disposed upon said chassis, coupled directly to said drive shaft of said electric motor at said first end of said electric motor and configured to pump high pressure fluid into the well bore;

a second fluid pump disposed upon said chassis, coupled directly to said drive shaft of said electric motor at said second end of said electric motor and configured to pump high pressure fluid into the well bore at the same time as said first fluid pump; and

first and second flex couplings engaged with and between said electric motor and said first and second respective fluid pumps and configured to allow relative movement of said electric motor and said first and second fluid pumps during and without disturbing the operation thereof,

wherein said drive shaft of said electric motor is coupled to said first and second fluid pumps so that said electric motor is capable of concurrently driving both said fluid pumps.

19. A method of providing a high volume of pressurized fluid from a single mobile high pressure fluid delivery system into an underground well bore, the method comprising:

on a single mobile chassis, positioning first and second high pressure fluid pumps on opposing sides of an electric motor, wherein the fluid pumps and electric motor are axially aligned on the chassis, the electric motor having a single drive shaft extending axially therethrough and outwardly therefrom at its opposing sides;

mechanically coupling the fluid pumps directly to drive shaft of the electric motor at the respective opposing sides of the motor so that the electric motor is configured to simultaneously drive both pumps to pump high pressure fluid into the well bore, the electric motor being configured to drive each fluid pump regardless of the operation of the other fluid pump;

engaging at least a first flex coupling with and between the electric motor and the first fluid pump and configured to allow movement of the electric motor and the first fluid pump relative to one another during and without disturbing the operation thereof;

engaging at least a second flex coupling with and between the electric motor and the second fluid pump and configured to allow movement of the electric motor and the second fluid pump relative to one another during and without disturbing the operation thereof;

electrically connecting a remotely controllable variable frequency drive disposed on the chassis to the electric motor and an external electric power source; and

the variable frequency drive providing electric power to the electric motor from the external electric power source and allowing the speed of the electric motor to be remotely controlled.

20. The method of claim 19 wherein the external electric power source is located remotely relative to the chassis, further including electrically coupling the variable frequency drive to the external electric power source with at least one cable.

21. The method of claim 19 wherein the first and second fluid pumps are mechanically coupled to the electric motor out of phase.