USOO941.041 OB2
`
`(12) United States Patent
`BrOussard et al.
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 9.410,410 B2
`Aug. 9, 2016
`
`(54) SYSTEM FOR PUMPING HYDRAULIC
`FRACTURING FLUID USINGELECTRIC
`PUMPS
`
`(71) Applicant: US Well Services LLC, Houston, TX
`(US)
`(72) Inventors: Joel N. Broussard, Lafayette, LA (US);
`Jeff McPherson, Spring, TX (US);
`Robert Kurtz, Fairmont, WV (US)
`(73) Assignee: US Well Services LLC, Houston, TX
`(US)
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 229 days.
`(21) Appl. No.: 13/679,.689
`
`(*) Notice:
`
`(22) Filed:
`
`Nov. 16, 2012
`
`(65)
`
`Prior Publication Data
`US 2014/O138079 A1
`May 22, 2014
`
`(2006.01)
`
`(51) Int. Cl.
`E2IB 43/26
`(52) U.S. Cl.
`CPC ...................................... E2IB 43/26 (2013.01)
`(58) Field of Classification Search
`CPC ....................................................... E21B 43/26
`USPC
`166/308.1, 177.5
`See application file for complete search history.
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`2.248,051 A * 7, 1941 Armstrong .................... 405,208
`3,722,595 A * 3/1973 Kiel .............
`... 166,308.4
`5,865,247 A * 2/1999 Paterson et al. ............ 166,252.1
`
`
`
`6,271,637 B1 * 8/2001 Kushion ........................ 318,434
`6,529,135 B1* 3/2003 Bowers et al. .....
`... 340,648
`6,931,310 B2 * 8/2005 Shimizu et al. ...
`701, 33.7
`7.312,593 B1* 12/2007 Streicher et al. .............. 3.18/473
`7,755,310 B2 * 7/2010 West et al. .........
`... 318, 400.02
`7,845,413 B2 * 12/2010 Shampine et al. ............ 166,369
`8,054,084 B2 * 1 1/2011 Schulz et al. ................. 324,545
`8,310,272 B2 * 1 1/2012 Quarto ........
`324,765.01
`8,354,817 B2 *
`1/2013 Yeh et al. ...................... 318,812
`8,789,601 B2 * 7/2014 Broussard ............... E21B 43.26
`166/1775
`9/2014 Kumano ......................... TO1/42
`8,838,341 B2
`9,018,881 B2 * 4/2015 Mao et al. ......
`... 318,490
`2007/02O1305 A1* 8, 2007 Heilman et al. ...
`... 366,141
`2010, 0132949 A1* 6, 2010 DeFosse et al. ............ 166,308.1
`2011/0272158 A1* 11, 2011 Neal ..............
`... 166,305.1
`2012/0085541 A1* 4/2012 Love et al. .....
`... 166,308.1
`2012/0205301 A1* 8, 2012 McGuire et al. .............. 210,151
`2012,0255734 A1 10, 2012 Coli et al.
`2013/0306322 A1* 11/2013 Sanborn .................. E21B 43.26
`166,308.1
`
`1/2014 Cryer et al.
`2014/OO 10671 A1
`2014/0251623 A1* 9, 2014 Lestz et al. ................. 166,308.2
`* cited by examiner
`Primary Examiner — Kenneth L Thompson
`(74) Attorney, Agent, or Firm — Bracewell LLP. Taylor P.
`Evans
`
`ABSTRACT
`(57)
`A system for hydraulically fracturing an underground forma
`tion in an oil orgas well to extract oil orgas from the forma
`tion, the oil orgas well having a wellbore that permits passage
`of fluid from the wellbore into the formation. The system
`includes a plurality of electric pumps fluidly connected to the
`well, and 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 plural
`ity of natural gas powered generators electrically connected
`to the plurality of electric pumps to provide electrical power
`to the pumps.
`
`21 Claims, 2 Drawing Sheets
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`LIBERTY EXHIBIT 1049, Page 1
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`U.S. Patent
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`Aug.9, 2016
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`Sheet 1 of 2
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`US 9,410,410 B2
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`LIBERTY EXHIBIT 1049, Page 2
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`LIBERTY EXHIBIT 1049, Page 2
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`U.S. Patent
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`Aug. 9, 2016
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`Sheet 2 of 2
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`US 9.410.410 B2
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`LIBERTY EXHIBIT 1049, Page 3
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`US 9,410,410 B2
`
`1.
`SYSTEM FOR PUMPNG HYDRAULC
`FRACTURING FLUID USINGELECTRIC
`PUMPS
`
`BACKGROUND OF THE INVENTION
`
`1. Field of the Invention
`This technology relates to hydraulic fracturing in oil and
`gas wells. In particular, this technology relates to pumping
`fracturing fluid into an oil or gas well using pumps powered
`by electric motors.
`2. Brief Description of Related Art
`Hydraulic fracturing has been used for decades to stimulate
`production from conventional oil and gas wells. The practice
`consists of pumping fluid into a wellbore at high pressure.
`Inside the wellbore, the fluid is forced into the formation
`being produced. When the fluid enters the formation, it frac
`tures, or creates fissures, in the formation. Water, as well as
`other fluids, and some solid proppants, are then pumped into
`the fissures to stimulate the release of oil and gas from the
`formation.
`Fracturing rock in a formation requires that the fracture
`fluid be pumped into the wellbore at very high pressure. This
`pumping is typically performed by large diesel-powered
`pumps. Such pumps are able to pump fracturing fluid into a
`wellbore at a high enough pressure to crack the formation, but
`they also have drawbacks. For example, the diesel pumps are
`very heavy, and thus must be moved on heavy duty trailers,
`making transport of the pumps between oilfield sites expen
`sive and inefficient. In addition, the diesel engines required to
`drive the pumps require a relatively high level of expensive
`maintenance. Furthermore, the cost of diesel fuel is much
`higher than in the past, meaning that the cost of running the
`pumps has increased.
`What is needed therefore, is a pump system for hydraulic
`fracturing fluid that overcomes the problems associated with
`diesel pumps.
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`SUMMARY OF THE INVENTION
`
`Disclosed herein is 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 for
`mation. The system includes a plurality of electric pumps
`fluidly connected to the well, and 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.
`The system also includes a plurality of generators electrically
`connected to the plurality of electric pumps to provide elec
`trical power to the pumps. At least some of the plurality of
`generators can be powered by natural gas, in addition, at least
`Some of the plurality of generators can be turbine generators.
`In one embodiment, the system further includes an A/C
`console and a variable frequency drive that controls the speed
`of the pumps. Furthermore, the electric pumps, as well as the
`electric generators, can be mounted on vehicles, and can be
`ported from one well to another. The vehicles can be trucks
`and can have at least five axles.
`Further disclosed herein is a system for fracturing a rock
`formation in an oil orgas well by pumping hydraulic fractur
`ing fluid into the well that includes a pump, an electric motor,
`a variable frequency drive, and a natural gas powered electric
`generator. The pump is configured for pumping the hydraulic
`fracturing fluid into the well, and then from the well into the
`formation, and is capable of pumping the hydraulic fracturing
`fluid at high pressure to crack the formation. The electric
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`motor can have a high-strength steel or steel alloy shaft
`attached to the pump and configured to drive the pump. The
`variable frequency drive can be connected to the electric
`motor to control the speed of the motor. In addition, the
`natural gas powered generator, which can be a turbine gen
`erator, can be connected to the electric motor and provide
`electric power to the electric motor.
`In one embodiment, the pump can be a triplex or a
`quinteplex pump, optionally rated at about 2250 hydraulic
`horsepower or more. In addition, the pump can also have 4.5
`inch diameter plungers with an eight inch stroke. In another
`embodiment, the electric motor can have a maximum con
`tinuous power output of about 1500 brake horsepower, 1750
`brake horsepower, or more, and a maximum continuous
`torque of about 8750 lb-ft or more. Furthermore, the electric
`motor can have a high temperature rating of about 1100
`degrees C. or more, and a shaft composed of 4340 alloy steel.
`In another embodiment, variable frequency drive can fre
`quently perform electric motor diagnostics to prevent damage
`to the electric motor if it becomes grounded or shorted. In
`addition, the variable frequency drive can include power
`semiconductor heat sinks having one or more thermal sensors
`monitored by a microprocessor to prevent semiconductor
`damage caused by excessive heat.
`Also disclosed herein is a system for hydraulically fractur
`ing 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 trailer for attachment to
`a truck. Two or more electric pumps can be attached to the
`trailer and are fluidly connected to the well, the electric
`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 are attached to the electric pumps to drive the pumps.
`The electric motors can also be attached to the trailer. A
`natural gas powered generator is provided for connection to
`the electric motor to provide electric power to the electric
`motor. The system of claim can further include a variable
`frequency drive attached to the trailer and connected to the
`electric motor to control the speed of the motor. In addition,
`the system can include a skid to which at least one of the
`electric pumps, the one or more electric motors, and the
`variable frequency drives are attached.
`Also disclosed herein is a process for stimulating an oil or
`gas well by hydraulically fracturing a formation in the well.
`The process includes the steps of pumping fracturing fluid
`into the well with an electrically powered pump at a high
`pressure so that the fracturing fluid enters and cracks the
`formation, the fracturing fluid having at least a liquid com
`ponent and a solid proppant, and inserting the Solid proppant
`into the cracks to maintain the cracks open, thereby allowing
`passage of oil and gas through the cracks. The process can
`further include powering the electrically powered pump with
`a natural gas generator. Such as, for example, a turbine gen
`eratOr.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`The present technology will be better understood on read
`ing the following detailed description of nonlimiting embodi
`ments thereof, and on examining the accompanying drawing,
`in which:
`FIG. 1 is a schematic plan view of equipment used in a
`hydraulic fracturing operation, according to an embodiment
`of the present technology; and
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`LIBERTY EXHIBIT 1049, Page 4
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`US 9,410,410 B2
`
`3
`FIG. 2 is a schematic plan view of equipment used in a
`hydraulic fracturing operation, according to an alternate
`embodiment of the present technology.
`
`DETAILED DESCRIPTION OF THE PREFERRED
`EMBODIMENT
`
`4
`prevent damage to a grounded or shorted electric motor 14.
`The electric motor diagnostics can be disabled, if desired,
`when using, for example, a low impedance or high-speed
`electric motor.
`In some embodiments, the pump 10 can optionally be a
`2250 HHP triplex or quinteplex pump. The pump 10 can
`optionally be equipped with 4.5 inch diameter plungers that
`have an eight (8) inch stroke, although other size plungers can
`be used, depending on the preference of the operator. The
`pump 10 can further include additional features to increase its
`capacity, durability, and robustness, including, for example,
`6.353 to 1 gear reduction, autuofrettaged steel or steel alloy
`fluid end, wing guided slush type valves, and rubber spring
`loaded packing.
`In addition to the above, certain embodiments of the
`present technology can include a skid (not shown) for Sup
`porting some or all of the above-described equipment. For
`example, the skid can Support the electric motor 14 and the
`pump 10. In addition, the skid can support the VFD. Struc
`turally, the skid can be constructed of heavy-duty longitudinal
`beams and cross-members made of an appropriate material,
`Such as, for example, Steel. The skid can further include
`heavy-duty lifting lugs, or eyes, that can optionally be of
`sufficient strength to allow the skid to be lifted at a single lift
`point.
`Referring back to FIG. 1, also included in the equipment is
`a plurality of electric generators 22 that are connected to, and
`provide power to, the electric motors 14 on the pump vehicles
`12. To accomplish this, the electric generators 22 can be
`connected to the electric motors 14 by power lines (not
`shown). The electric generators 22 can be connected to the
`electric motors 14 via power distribution panels (not shown).
`In certain embodiments, the electric generators 22 can be
`powered by natural gas. For example, the generators can be
`powered by liquefied natural gas. The liquefied natural gas
`can be converted into a gaseous form in a vaporizer prior to
`use in the generators. The use of natural gas to power the
`electric generators 22 can be advantageous because, where
`the well is a natural gas well, above ground natural gas vessels
`24 can already be placed on site to collect natural gas pro
`duced from the well. Thus, a portion of this natural gas can be
`used to power the electric generators 22, thereby reducing or
`eliminating the need to import fuel from offsite. If desired by
`an operator, the electric generators 22 can optionally be natu
`ral gas turbine generators. Such as those shown in FIG. 2.
`FIG. 1 also shows equipment for transporting and combin
`ing the components of the hydraulic fracturing fluid used in
`the system of the present technology. In many wells, the
`fracturing fluid contains a mixture of water, sand or other
`proppant, acid, and other chemicals. Examples of fracturing
`fluid components include acid, anti-bacterial agents, clay sta
`bilizers, corrosion inhibitors, friction reducers, gelling
`agents, iron control agents, pH adjusting agents, scale inhibi
`tors, and Surfactants. Historically, diesel has at times been
`used as a substitute for water in cold environments, or where
`a formation to be fractured is water sensitive, such as, for
`example, clay. The use of diesel, however, has been phased
`out over time because of price, and the development of newer,
`better technologies.
`In FIG. 1, there are specifically shown sand transporting
`vehicles 26, an acid transporting vehicle 28, vehicles for
`transporting other chemicals 30, and a vehicle carrying a
`hydration unit 32, Such as, for example, a water pump. Also
`shown are fracturing fluid blenders 34, which can be config
`ured to mix and blend the components of the hydraulic frac
`turing fluid, and to supply the hydraulic fracturing fluid to the
`pumps 10. In the case of liquid components, such as water,
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`The foregoing aspects, features, and advantages of the
`present technology will be further appreciated when consid
`ered with reference to the following description of preferred
`embodiments and accompanying drawing, wherein like ref
`erence numerals represent like elements. In describing the
`preferred embodiments of the technology illustrated in the
`appended drawing, specific terminology will be used for the
`sake of clarity. However, the technology is not intended to be
`limited to the specific terms used, and it is to be understood
`that each specific term includes equivalents that operate in a
`similar manner to accomplish a similar purpose.
`FIG. 1 shows a plan view of equipment used in a hydraulic
`fracturing operation. Specifically, there is shown a plurality of
`pumps 10 mounted to pump vehicles 12. The pump vehicles
`12 can be trucks having at least five axles. In the embodiment
`shown, the pumps 10 are powered by electric motors 14,
`which can also be mounted to the pump vehicles 12. The
`pumps 10 are fluidly connected to the wellhead 16 via the
`missile 18. As shown, the pump vehicles 12 can be positioned
`near enough to the missile 18 to connect fracturing fluid lines
`20 between the pumps 10 and the missile 18. The missile 18
`is then connected to the wellhead 16 and configured to deliver
`fracturing fluid provided by the pumps 10 to the wellhead 16.
`In some embodiments, each electric motor 14 can be
`capable of delivering about 1500 brake horsepower (BHP),
`1750 BHP, or more, and each pump 10 can optionally be rated
`for about 2250 hydraulic horsepower (HHP) or more. In
`addition, the components of the system, including the pumps
`10 and the electric motors 14, can be capable of operating
`during prolonged pumping operations, and in temperature in
`a range of about 0 degrees C. or less to about 55 degrees C. or
`more. In addition, each electric motor 14 can be equipped
`with a variable frequency drive (VFD), and an A/C console,
`that controls the speed of the electric motor 14, and hence the
`speed of the pump 10.
`The electric motors 14 of the present technology can be
`designed to withstand an oilfield environment. Specifically,
`Some pumps 10 can have a maximum continuous power out
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`put of about 1500 BHP, 1750 BHP, or more, and a maximum
`continuous torque of about 8750 lb-ft or more. Furthermore,
`electric motors 14 of the present technology can include class
`Hinsulation and high temperature ratings, such as about 1100
`degrees C. or more. In some embodiments, the electric motor
`14 can include a single shaft extension and huh for high
`tension radial loads, and a high strength 4340 alloy steel shaft,
`although other Suitable materials can also be used.
`The VFD can be designed to maximize the flexibility,
`robustness, serviceability, and reliability required by oilfield
`applications, such as hydraulic fracturing. For example, as far
`as hardware is concerned, the VFD can include packaging
`receiving a high rating by the National Electrical Manufac
`turers Association (such as nema 1 packaging), and power
`semiconductor heat sinks having one or more thermal sensors
`monitored by a microprocessor to prevent semiconductor
`damage caused by excessive heat. Furthermore, with respect
`to control capabilities, the VFD can provide complete moni
`toring and protection of drive internal operations while com
`municating with an operator via one or more user interfaces.
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`For example, motor diagnostics can be performed frequently
`(e.g., on the application of power, or with each start), to
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`LIBERTY EXHIBIT 1049, Page 5
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`acids, and at least some chemicals, the components can be
`supplied to the blenders 34 via fluid lines (not shown) from
`the respective component vehicles, or from the hydration unit
`32. In the case of Solid components, such as sand, the com
`ponent can be delivered to the blender 34 by a conveyor belt
`38. The water can be supplied to the hydraulic unit 32 from,
`for example, water tanks 36 onsite. Alternately, the water can
`be provided by water trucks. Furthermore, water can be pro
`vided directly from the water tanks 36 or water trucks to the
`blender 34, without first passing through the hydration unit
`32.
`Pump control and data monitoring equipment 40 can be
`mounted on a control vehicle 42, and connected to the pumps
`10, electric motors 14, blenders 34, and other downhole sen
`sors and tools (not shown) to provide information to an opera
`tor, and to allow the operator to control different parameters
`of the fracturing operation. For example, the pump control
`and data monitoring equipment 40 can include an A/C con
`sole that controls the VFD, and thus the speed of the electric
`motor 14 and the pump 10. Other pump control and data
`monitoring equipment can include pump throttles, a pump
`VFD fault indicator with a reset, a general fault indicator with
`a reset, a main estop, a programmable logic controller for
`local control, and a graphics panel. The graphics panel can
`include, for example, a touchscreen interface.
`Referring now to FIG. 2, there is shown an alternate
`embodiment of the present technology. Specifically, there is
`shown a plurality of pumps 110 which, in this embodiment,
`are mounted to pump trailers 112. As shown, the pumps 110
`can optionally be loaded two to a trailer 112, thereby mini
`mizing the number of trailers needed to place the requisite
`number of pumps at a site. The ability to load two pumps 110
`on one trailer 112 is possible because of the relatively light
`weight of the electric pumps 110 compared to other known
`pumps, such as diesel pumps. In the embodiment shown, the
`pumps 110 are powered by electric motors 114, which can
`also be mounted to the pump trailers 112. Furthermore, each
`electric motor 114 can be equipped with a VFD, and an A/C
`console, that controls the speed of the motor 114, and hence
`the speed of the pumps 110.
`In addition to the above, the embodiment of FIG. 2 can
`include a skid (not shown) for Supporting some or all of the
`above-described equipment. For example, the skid can Sup
`port the electric motors 114 and the pumps 110. In addition,
`the skid can support the VFD. Structurally, the skid can be
`constructed of heavy-duty longitudinal beams and cross
`members made of an appropriate material. Such as, for
`example, steel. The skid can further include heavy-duty lift
`ing lugs, or eyes, that can optionally be of Sufficient strength
`to allow the skid to be lifted at a single lift point.
`The pumps 110 are fluidly connected to a wellhead 116 via
`a missile 118. As shown, the pump trailers 112 can be posi
`tioned near enough to the missile 118 to connect fracturing
`fluid lines 120 between the pumps 110 and the missile 118.
`The missile 118 is then connected to the wellhead 116 and
`configured to deliver fracturing fluid provided by the pumps
`110 to the wellhead 116.
`Still referring to FIG. 2, this embodiment also includes a
`plurality of turbine generators 122 that are connected to, and
`provide power to, the electric motors 114 on the pump trailers
`112. To accomplish this, the turbine generators 122 can be
`connected to the electric motors 114 by power lines (not
`shown). The turbine generators 122 can be connected to the
`electric motors 114 via power distribution panels (not
`shown). In certain embodiments, the turbine generators 122
`can be powered by natural gas, similar to the electric genera
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`US 9,410,410 B2
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`tors 22 discussed above in reference to the embodiment of
`FIG. 1. Also included are control units 144 for the turbine
`generators 122.
`The embodiment of FIG. 2 can include other equipment
`similar to that discussed above. For example, FIG. 2 shows
`sand transporting vehicles 126, acid transporting vehicles
`128, other chemical transporting vehicles 130, hydration
`units 132, blenders 134, water tanks 136, conveyor belts 138,
`and pump control and data monitoring equipment 140
`mounted on a control vehicle 142. The function and specifi
`cations of each of these is similar to corresponding elements
`shown in FIG. 1.
`Use of pumps 10, 110 powered by electric motors 14, 114
`and natural gas powered electric generators 22 (or turbine
`generators 122) to pump fracturing fluid into a well is advan
`tageous over known systems for many different reasons. For
`example, the equipment pumps, electric motors, and genera
`tors) is lighter than the diesel pumps commonly used in the
`industry. The lighter weight of the equipment allows loading
`of the equipment directly onto a truck body. In fact, where the
`equipment is attached to a skid, as described above, the skid
`itself can be lifted on the truck body, along with all the
`equipment attached to the skid, in one simple action. Alter
`natively, and as shown in FIG. 2, trailers 112 can be used to
`transport the pumps 110 and electric motors 114, with two or
`more pumps 110 carried on a single trailer 112. Thus, the
`same number of pumps 110 can be transported on fewer
`trailers 112. Known diesel pumps, in contrast, cannot be
`transported directly on a truck body or two on a trailer, but
`must be transported individually on trailers because of the
`great weight of the pumps.
`The ability to transfer the equipment of the present tech
`nology directly on a truck body or two to a trailer increases
`efficiency and lowers cost. In addition, by eliminating or
`reducing the number of trailers to carry the equipment, the
`equipment can be delivered to sites having a restricted
`amount of space, and can be carried to and away from work
`sites with less damage to the Surrounding environment.
`Another reason that the electric pump system of the present
`technology is advantageous is that it runs on natural gas.
`Thus, the fuel is lower cost, the components of the system
`require less maintenance, and emissions are lower, so that
`potentially negative impacts on the environment are reduced.
`In practice, a hydraulic fracturing operation cart be carried
`out according to the following process. First, the water, sand,
`and other components are blended to form a fracturing fluid,
`which is pumped down the well by the electric-powered
`pumps. Typically, the well is designed so that the fracturing
`fluid can exit the wellbore at a desired location and pass into
`the Surrounding formation. For example, in Some embodi
`ments the wellbore can have perforations that allow the fluid
`to pass from the wellbore into the formation. In other embodi
`ments, the wellbore can include an openable sleeve, or the
`well can be open hole. The fracturing fluid can be pumped
`into the wellbore at a high enough pressure that the fracturing
`fluid cracks the formation, and enters into the cracks. Once
`inside the cracks, the sand, or other proppants in the mixture,
`wedges in the cracks, and holds the cracks open.
`Using the pump control and data monitoring equipment 40,
`the operator can monitor, gauge, and manipulate parameters
`of the operation, Such as pressures, and Volumes of fluids and
`proppants entering and exiting the well. For example, the
`operator can increase or decrease the ratio of sand to water as
`the fracturing process progresses and circumstances change.
`This process of injecting fracturing fluid into the wellbore
`can be carried out continuously, or repeated multiple times in
`stages, until the fracturing of the formation is optimized.
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`LIBERTY EXHIBIT 1049, Page 6
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`Optionally, the wellbore can be temporarily plugged between
`each stage to maintain pressure, and increase fracturing in the
`formation. Generally, the proppant is inserted into the cracks
`formed in the formation by the fracturing, and left in place in
`the formation to prop open the cracks and allow oil or gas to
`flow into the wellbore.
`While the technology has been shown or described in only
`some of its forms, it should be apparent to those skilled in the
`art that it is not so limited, but is susceptible to various
`changes without departing from the scope of the technology.
`Furthermore, it is to be understood that the above disclosed
`embodiments are merely illustrative of the principles and
`applications of the present technology. Accordingly, numer
`ous modifications can be made to the illustrative embodi
`ments and other arrangements can be devised without depart
`ing from the spirit and scope of the present technology as
`defined by the appended claims.
`What is claimed is:
`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 electric pumps fluidly connected to the well
`and powered by at least one electric motor, and config
`ured to pump fluid into the wellbore at high pressure so
`that the fluid passes from the wellbore into the forma
`tion, and fractures the formation; and
`a variable frequency drive connected to the electric motor
`to control the speed of the motor, wherein the variable
`frequency drive frequently performs electric motor diag
`nostics to prevent damage to the at least one electric
`motor.
`2. The system of claim 1, further comprising:
`an AIC console and a variable frequency drive that controls
`the speed of the pumps.
`3. The system of claim 1, wherein the electric pumps are
`mounted on vehicles, and can be ported from one well to
`another.
`4. The system of claim 1, further comprising:
`a plurality of generators electrically connected to the plu
`rality of electric pumps to provide electrical power to the
`pumps.
`5. The system of claim 4, wherein at least some of the
`plurality of generators are powered by natural gas.
`6. The system of claim 4, wherein at least some of the
`plurality of generators are turbine generators.
`7. The system of claim 4, wherein the electric pumps and
`generators are mounted on vehicles, and can be ported from
`one well to another.
`8. The system of claim 4, wherein the vehicles are trucks
`having at least five axles.
`9. The system of claim 1, wherein the variable frequency
`drive has one or more power semiconductor heat sinks having
`thermal sensors monitored by a microprocessor to prevent
`damage caused by excessive heat.
`10. A system for fracturing a rock formation in an oil orgas
`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
`
`5
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`10
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`15
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`25
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`30
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`35
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`40
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`45
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`50
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`55
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`60
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`US 9,410,410 B2
`
`8
`pump 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
`shaft attached to the pump and configured to drive the
`pump; and
`a variable frequency drive connected to the electric motor
`to control the speed of the motor. Wherein the variable
`frequency drive frequently performs electric motor diag
`nostics to prevent damage to the electric motor.
`11. The system of claim 10, wherein the pump is a triplex
`or a quinteplex pump rated at about 2250 hydraulic horse
`power or more.
`12. The system of claim 11, wherein the pump has 4.5 inch
`diameter plungers with an eight inch stroke.
`13. The system of claim 10, wherein the electric motor has
`a maximum continuous power output of about 1750 brake
`horsepower or more.
`14. The system of claim 13, wherein the electric motor has
`a...maximum continuous torque of about 8750 lb-ft or more.
`15. The system of 14, wherein the electric motor has a high
`temperature rating of about 400 degrees C. or more.
`16. The system of 15, wherein the shafte electric motor is
`composed of 4340 alloy steel.
`17. The system of claim 10, further comprising:
`a natural gas powered generator connected to the electric
`motor that provides electric power to the electric motor.
`18. The system of claim 17, wherein the natural gas pow
`ered generator is a turbine generator.
`19. 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 for attachment to a truck;
`two or more electric pumps attached to the trailer and
`fluidly connected to the well, the electric pumps config
`ured to pump fluid into the wellbore at high pressure so
`that the fluid passes from the wellbore into the forma
`tion, and fractures the formation;
`one or more electric motors attached to the electric pumps
`to drive the pumps, the electric motors attached to the
`trailer; and
`a variable frequency drive connected to the electric motor
`to control the speed of the motor, wherein the variable
`frequency drive frequently performs electric motor diag
`nostics to prevent damage to the one or more electric
`motorS.
`20. The system of claim 19, further comprising:
`a skid to which at least one of the electric pumps, the one or
`more electric motors, and the variable frequency drives
`are attached.
`21. The system of claim 19, further comprising:
`a natural gas powered generator for connection to the elec
`tric motor that provides electric power to the electric
`motor.
`
`LIBERTY EXHIBIT 1049, Page 7
`
`

`

`UNITED STATES PATENT AND TRADEMARK OFFIC