U.S. patent application number 14/511858 was filed with the patent office on 2015-04-30 for fracturing systems and methods for a wellbore.
This patent application is currently assigned to PROSTIM LABS, LLC. The applicant listed for this patent is Prostim Labs, LLC. Invention is credited to Audis C. Byrd, David A. Carroll, James H. Junkins, Robert S. Lestz, Norman S. Myers, John F. Thrash.
Application Number | 20150114652 14/511858 |
Document ID | / |
Family ID | 52994112 |
Filed Date | 2015-04-30 |
United States Patent
Application |
20150114652 |
Kind Code |
A1 |
Lestz; Robert S. ; et
al. |
April 30, 2015 |
FRACTURING SYSTEMS AND METHODS FOR A WELLBORE
Abstract
The disclosure contained herein describes systems, units, and
methods usable to stimulate a formation including a pump usable to
pressurize fluid, an electric-powered driver in communication with
and actuating the pump, and an electrical power source in
communication with and powering the electric-powered driver. The
electrical power source can include on-site generators and/or grid
power sources, and transformers can be used to alter the voltage
received to a voltage suitable for powering the electric-powered
driver. Air moving devices associated with the electric-powered
driver can be used to provide air proximate to the pump to disperse
gasses. In combination with fluid supply and/or proppant addition
subsystems, the pump can be used to fracture a formation.
Inventors: |
Lestz; Robert S.; (Missouri
City, TX) ; Thrash; John F.; (Houston, TX) ;
Byrd; Audis C.; (Big Sandy, TX) ; Junkins; James
H.; (Houston, TX) ; Myers; Norman S.; (Spring,
TX) ; Carroll; David A.; (Pinehurst, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Prostim Labs, LLC |
Houston |
TX |
US |
|
|
Assignee: |
PROSTIM LABS, LLC
|
Family ID: |
52994112 |
Appl. No.: |
14/511858 |
Filed: |
October 10, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14199461 |
Mar 6, 2014 |
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14511858 |
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61889187 |
Oct 10, 2013 |
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61915093 |
Dec 12, 2013 |
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61889187 |
Oct 10, 2013 |
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61870350 |
Aug 27, 2013 |
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61807699 |
Apr 2, 2013 |
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61790942 |
Mar 15, 2013 |
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61774237 |
Mar 7, 2013 |
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Current U.S.
Class: |
166/308.1 ;
166/66.4 |
Current CPC
Class: |
E21B 43/26 20130101;
C09K 8/62 20130101; E21B 43/267 20130101 |
Class at
Publication: |
166/308.1 ;
166/66.4 |
International
Class: |
E21B 43/26 20060101
E21B043/26; E21B 43/267 20060101 E21B043/267 |
Claims
1. An electrical power system for providing fracturing materials to
a formation at a pressure sufficient to stimulate the formation,
the power system comprising: a pump for pressurizing the fracturing
material; an electric motor coupled to the pump, together defining
a pump/motor combination, the electric motor configured to provide
mechanical energy to the pump for the purposes of actuating the
pump; and a variable frequency drive coupled to the electric motor
and to a power source, wherein the variable frequency drive
receives electricity from the power source, and wherein the
variable frequency drive provides an electrical signal to the
electric motor.
2. The system of claim 1, wherein the variable frequency drive is
coupled to a single pump/motor combination.
3. The system of claim 1, wherein the variable frequency drive is
coupled to a plurality of pump/motor combinations.
4. The system of claim 1, wherein the variable frequency drive is
remote from physical proximity with the pump/motor combination.
5. The system of claim 1, wherein the fracturing material comprises
a volatile material.
6. The system of claim 1, wherein the fracturing material comprises
a non-volatile material.
7. The system of claim 6, wherein the variable frequency drive is
located in physical proximity with a pump/motor combination.
8. The system of claim 1, wherein the variable frequency drive is
located in physical proximity with a pump/motor combination.
9. The system of claim 1, wherein the electric motor is fire
resistant.
10. The system of claim 1, wherein the electric motor is explosion
resistant.
11. The system of claim 1, further comprising a mobile platform,
wherein the pump, the electric motor, the variable frequency drive,
or combinations thereof are positioned on the mobile platform.
12. The system of claim 1, further comprising a proppant addition
subsystem adapted to enable a proppant to be added to the
fracturing material.
13. The system of claim 1, further comprising a transformer coupled
between the power source and the VFD, the transformer being
configured to convert electricity received from the power source
from a first voltage to a second voltage, wherein the second
voltage is a voltage within a range useable by the VFD.
14. A method of electrically powering a system for providing a
fracturing material to a formation at a pressure sufficient to
stimulate the formation, the method comprising: receiving into a
variable frequency drive electricity from a power source;
outputting an electrical signal from the variable frequency drive;
inputting the electrical signal into an electrical-powered driver;
converting the electrical signal into mechanical energy through the
use of the electrical-powered driver; transferring the mechanical
energy from the electrical-powered driver into a pump; using the
mechanical energy to actuate the pump in order to pressurize a
volume of the fracturing material.
15. The method of claim 14, further comprising converting the
electricity from a first voltage to a second voltage prior to
inputting the electricity into the variable frequency drive.
16. The method of claim 15, wherein the conversion of the
electricity from the first voltage to the second voltage is
achieved through the use of a transformer coupled between the power
source and the variable frequency drive.
17. The method of claim 14, wherein at least a portion of the
electrical signal is inputted into a plurality of
electrical-powered drivers, and wherein each of the plurality of
electrical-powered drivers outputs the second electrical signal to
a pump.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This applications claims priority to U.S. Provisional
Application for patent, having the Application Ser. No. 61/889,187,
filed Oct. 10, 2013.
[0002] This application further claims priority to U.S.
Non-Provisional application for patent, having the application Ser.
No. 14/99461, and further claims priority to claims priority to the
U.S. Provisional Application for patent, having the Application
Ser. No. 61/774,237, filed Mar. 7, 2013; the U.S. Provisional
Application for patent, having the Application Ser. No. 61/790,942,
filed Mar. 15, 2013; the U.S. Provisional Application for patent,
having the Application Ser. No. 61/807,699, filed Apr. 2, 2013; the
U.S. Provisional Application for patent, having the Application
Ser. No. 61/870,350, filed Aug. 27, 2013; the U.S. Provisional
Application for patent, having the Application Ser. No. 61/889,187
filed Oct. 10, 2013; and the U.S. Provisional Application for
patent, having the Application Ser. No. 61/915,093, filed Dec. 12,
2013.
[0003] All of the above-referenced applications are incorporated by
reference herein in their entirety.
FIELD OF THE INVENTION
[0004] The present disclosure relates generally, to systems,
methods, devices, and compositions usable within a wellbore, and
more specifically, to systems and methods for fracturing a
formation to stimulate production (e.g., of hydrocarbons)
therefrom.
BACKGROUND OF THE INVENTION
[0005] To stimulate and/or increase the production of hydrocarbons
from a well, a process known as fracturing (colloquially referred
to as "fracing") is performed. In brief summary, a pressurized
fluid--often water--is pumped into a producing region of a
formation at a pressure sufficient to create fractures in the
formation, thereby enabling hydrocarbons to flow from the formation
with less impedance. Solid matter, such as sand, ceramic beads,
and/or similar particulate-type materials, can be mixed with the
fracturing fluid, this material generally remaining within the
fractures after the fractures are formed. The solid material, known
as proppant, serves to prevent the fractures from closing and/or
significantly reducing in size following the fracturing operation,
e.g., by "propping" the fractures in an open position. Some types
of proppant can also facilitate the formation of fractures when
pumped into the formation under pressure. While the presence of
proppant in the fractures can hinder the permeability of the
formation, e.g., by impeding the flow of hydrocarbons toward the
wellbore, the increased flow created by the propped fractures
normally outweighs any impedance caused by the proppant. The
materials being transported into a formation for the purposes of
fracturing may be referred to as "fracturing material." The
fracturing material may comprise any material that is being
transported into a formation for fracturing purposes, and may
include fluids, gasses, solids, or combinations thereof.
[0006] Fracturing using aqueous fluids is often undesirable due to
the negative effects of water on the formation. For example, clays
and other formation components can swell when exposed to water,
while salts and other formation components may dissolve, such that
exposure to a significant quantity of water can destabilize a
formation. Use of water and other aqueous fluids also generates
issues regarding disposal. Specifically, aqueous fracturing fluid
recovered from a well (e.g., subsequent to a fracturing operation)
contains various wellbore fluids and other chemicals (e.g.,
additives to facilitate fracturing using the fluid), and as such,
the recovered fracturing fluid must be collected and stored at the
surface and disposed of in an environmentally acceptable manner, as
required by numerous regulations. Such a process can add
considerable time and expense to a fracturing operation.
[0007] Non-aqueous fracturing fluids have been used as an
alternative, one such successful class including hydrocarbon-based
fluids (e.g., crude/refined oils, methanol, diesel, condensate,
liquid petroleum glass (LPG) and/or other aliphatic or aromatic
compounds). Hydrocarbon-based fracturing fluids are inherently
compatible with most reservoir formations, being generally
non-damaging to formations while creating acceptable fracture
geometry. However, due to the flammability of hydrocarbon-based
fluids, enhanced safety preparations and equipment are necessary
when using such fluids for wellbore operations. Additionally, many
hydrocarbon-based fluids are volatile and/or otherwise unsuitable
for use at wellbore temperatures and pressures, while lacking the
density sufficient to carry many types of proppant. As such, it is
common practice to use chemical additives (e.g., gelling agents,
viscosifiers, etc.) to alter the characteristics of the fluids. An
example a system describing use of liquid petroleum gas is
described in U.S. Pat. No. 8,408,289, which is incorporated by
reference herein in its entirety. Use of chemical additives
generates waste and disposal issues similar to those encountered
when performing fracturing operations using aqueous fluids.
[0008] Independent of the type of fracturing fluid and proppant
used, a fracturing operation typically requires use of one or more
high pressure pumps to pressurize the fracturing fluid that is
pumped into a wellbore. Conventionally, such equipment is
driven/powered using diesel engines, which can be responsible for
significant quantities of noise, pollution, and expense at a
worksite. Electric drive systems have been contemplated as an
alternative to diesel engines; however, such systems require
numerous pieces of equipment, extensive cabling and/or similar
conduits, and typically utilize on-site power generation, such as a
natural gas turbine. Use of turbine prime movers and similar
equipment may be unsuitable when utilizing fracturing fluids that
include flammable components. An exemplary electrically powered
system for use in fracturing underground formations is described in
published United States Patent Application 2012/0255734, which is
incorporated by reference herein in its entirety.
[0009] A need exists for systems and methods for fracturing and/or
stimulating a subterranean formation that can overcome issues of
formation damage/compatibility, flammability, proppant delivery,
and/or power supply.
BRIEF SUMMARY OF THE INVENTION
[0010] Embodiments usable within the scope of the present
disclosure include systems usable for stimulating a formation
(e.g., by forming fractures therein), such as through the provision
of pressurized fluid to the formation through a wellbore. A fluid
supply system, adapted to provide a fluid (e.g., a fracturing
fluid, such as propane, other alkanes, halogenated hydrocarbons,
other hydrocarbons, or any other fracturing fluid, such as water)
can be provided in fluid communication with the formation. A power
subsystem that includes one or more pumps (e.g., high pressure
pumps, usable for fracturing operations) in communication with the
fluid can be used to pressurize the fluid to a pressure sufficient
to stimulate the formation. In an embodiment, a proppant addition
system can be used to provide solid material (e.g., proppant, such
as sand, ceramic, beads, glass bubbles, crystalline materials, or
any other solid and/or particulate matter usable to maintain
fractures in a formation) into the fluid.
[0011] In addition to the one or more pumps, the power subsystem
can include an electric-powered driver (e.g., an electric motor) in
communication with and actuating the pump(s), and an electrical
power source (e.g., a turbine-powered generator, a grid power
source, and/or another source of AC or DC power), in communication
with and powering the electric-powered driver. Alternatively or
additionally, a generator can be powered using reciprocating
engines (e.g., diesel engines) without departing from the scope of
the present disclosure. A single pump can be actuated using a
single electric-powered driver or multiple electric-powered
drivers, and multiple pumps can be actuated using a single
electric-powered driver or multiple electric-powered drivers.
Similarly, a single power source can power one or multiple
electric-powered drivers, or one or multiple electric-powered
drivers can be powered by multiple power sources. In an embodiment,
the power subsystem can be adapted for simultaneous or
selective/alternative use of an on-site power source, such as a
generator powered by a natural gas turbine, or a grid power source
(e.g., power lines or similar conduits associated with a remote
power source).
[0012] One or more transformers can be used to alter voltage from
the power source to a voltage suitable for powering the
electric-powered drivers. One or more variable frequency drives
("VFD(s)") can be provided in communication with the transformer(s)
and respective electric-powered drivers.
[0013] In an embodiment, at least one VFD, electric-powered driver,
and pump can be provided on a mobile vehicle to facilitate modular
positioning, e.g., at a worksite. One or more transformers can also
be provided, on or off of the mobile vehicle. An electrical power
source can be engaged with a transformer (and subsequently, to
other associated components) via a single electric conduit,
eliminating much of the cabling/conduits present at conventional
worksites.
[0014] In an embodiment, an air-moving device (e.g., a blower)
associated with the electric-powered driver (typically used to cool
the electric-powered driver), can be used to flow air proximate to
a pump, e.g., for dispersing volatile gases. For example, when
using propane as a fracturing fluid, the accumulation of propane
proximate to the pump could create a flammable condition (e.g., at
a propane concentration of approximately 2.2% to 9.5% in air),
while the continuous movement of air proximate to the pump would
prevent accumulation of flammable components at a concentration
sufficient for ignition. An enclosed conduit extending between the
electric-powered driver and the pump can be used to facilitate the
flow of air. Alternatively or additionally, the electric-powered
driver and the pump could occupy a single housing. In one
embodiment, one or more protrusions (e.g., fins, blades, or similar
projections) extending from the drive shaft extending between the
electric-powered driver and the pump can be contacted by air from
the air-moving device, such that the flow of air imparts motive
force to the drive shaft. The rotation of such protrusions, itself
(e.g., when the drive shaft is rotated to actuate the pump), can
serve to circulate air proximate to the pump, in addition to or in
lieu of an air-moving device associated with the electric-powered
driver.
[0015] Embodiments of the system usable within the scope of this
disclosure may provide for VFD(s) having an active front end. The
active front end that may be used with the VFD(s) actively switches
insulated-gate bipolar transistors (IGBT's) at a frequency of
approximately 3,500 Hz and inductor-capacitor-inductor passive
filters (LCLs). Actively filtering the signals inputted into the
VFD the enables active signal modulation which reduces the
possibility of, and may be used to actively prevent, the system
developing harmonics that could adversely affect the transport of
the fracturing materials. Such an active front end provides for
superior line canceling harmonics when using electricity from the
power grid as compared to conventional diode bridge rectifies, or
other passive filtering techniques.
[0016] Furthermore, embodiments of the system may comprise a logic
system for controlling multiple pumps used in the same fracturing
operation at the same time. The logic system may comprise one or
more sensors that actively monitor a multitude of different
parameters of the pumping system. The logic system may further
comprise an active feedback loop that uses the data collected by
the sensor(s) in order to responsively modulate the characteristics
of the pumping action of one or more pumps in order to optimize the
flow of fracturing materials into the formation and/or to prevent
potentially hazardous conditions from arising due to the
interactions between multiple pump systems.
[0017] The electrical components of the system described herein may
be operated at any of a multitude of different voltages; however,
without disclaiming any functional voltage ranges, for the purposes
of the description of embodiments in the present disclosure it will
be assumed that the voltage of operation is approximately 4160
volts or "Medium Voltage".
[0018] The use of Medium Voltage is specifically described herein
because it affords a number of potential benefits to the system.
Such advantages include the elimination of the need for a front end
transformer for converting incoming electricity from a power source
to a voltage that is useable by a VFD. The elimination of the front
end transformers reduces the amount of equipment required for use
of the system, which in turn reduces the cost and logistical
requirements, (e.g. the cost of the front end transformer(s)
themselves, the cost and planning of transportation of the
equipment, weight of equipment on site, etc.) of setting up and
running the system.
[0019] Furthermore the use of Medium Voltage allows for fewer
and/or smaller electrical cables running between the electrical
components of the system than would be required in a lower voltage
configuration. The reduction of cables reduces both the cost of
setting up the system and the clutteredness of the work site.
[0020] Included in the scope of the present disclosure is an
electrical power system for providing fracturing materials to a
formation at a pressure sufficient to stimulate the formation. The
electrical power system comprises at least one pump, at least one
electric-powered driver, and at least one VFD. In an embodiment of
the system the VFD receives electricity from an electrical power
source, the VFD then converts that electricity into an electrical
signal that is then transmitted to the electric-powered driver. The
electric-powered driver converts the electrical signal provided by
the VFD into mechanical energy that is used to actuate the pump.
The actuation of the pump by the mechanical energy produced by the
electric-powered driver causes the pump to pressurize a volume of
fracturing material. The pressurized fracturing material may be
transported into a formation for the purposes of stimulating the
formation.
[0021] Embodiments of the electrical power system may be configured
so that a single VFD may provide the electrical signal to a
plurality of electrical motors, each of which power an associated
pump. This configuration wherein a single VFD powers multiple
motor/pump combinations may provide benefits to fracturing systems
that require fracturing material to be transported to a formation
at a high flow rate but at a low pressure.
[0022] Alternate embodiments of the electrical power system may be
configured so that a single VFD may provide the electrical signal
to a single motor/pump combination. This configuration may provide
for benefits in situations when a fracturing system requires
fracturing material to be transported to a formation at a high
pressure.
[0023] Embodiments of the electrical power system may be configured
such that the VFD is positioned proximate to the motor/pump
combination(s). This configuration may allow for reduced
infrastructure requirements at the operation site, and may enable
the entire electrical power system to be configured so as to be
supported by, and transportable on, a mobile platform.
[0024] Alternative embodiments of the electrical power system may
be configured such that the VFD is positioned in a location remote
from the motor/pump combination(s). This configuration may assist
in preventing dangers on the site by physically removing potential
ignition sources (the VFD) from proximity with the components of
the system that interact with the fracturing materials. This may be
of particular importance when the fracturing materials being
pressurized comprise volatile materials.
[0025] Embodiment of the electrical power system may comprise an
electric-powered driver(s) that are designed to be fire and/or
explosion resistant.
[0026] Embodiments of the electrical power system may further
comprise a proppant addition subsystem configured to add proppant
to the fracturing materials being pressurized.
[0027] The electrical power system may further comprise an agitator
configured to enable viscous fracturing materials to be transported
to the formation. Such an agitator may use vibration to enable the
transportation of the viscous fracturing material.
[0028] Embodiments of the electrical power system may further
comprise a transformer for converting the electricity being
received from a first voltage to a second voltage prior to the
electricity being inputted into the VFD.
[0029] Additionally included in the scope of the present disclosure
is a method of electrically powering a system for providing a
fracturing material to a formation at a pressure sufficient to
stimulate the formation. An embodiment of the method comprises
first receiving electricity from a power source. The electricity is
inputted into a VFD which converts the electricity into a
electrical signal. The electrical signal is then transferred from
the VFD to an electrical motor. The electrical motor converts the
electrical signal provided from the VFD into mechanical energy. The
mechanical energy from the electrical motor is communicated to a
pump which uses the mechanical energy from the electrical motor to
pressurize a volume of fracturing material.
[0030] Embodiments of the method may further comprise the step of
converting the electricity being received from a first voltage to a
second voltage prior to the electricity being inputted into the
VFD. A transformer may be used to convert the electricity from the
first voltage to the second voltage. This step may be required when
the voltage being provided by the power source is outside of the
range of voltages usable by the VFD.
[0031] Embodiments of the method may provide for transmitting a
portion of the electrical signal provided by the VFD to a plurality
of electric-powered drivers. The portion of the electrical signal
may be provided to the plurality of eclectic motors in series or in
parallel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] The novel features believed characteristic of the disclosed
subject matter will be set forth in any claims that are filed
later. The disclosed subject matter itself, however, as well as a
preferred mode of use, further objectives, and advantages thereof,
will best be understood by reference to the following detailed
description of an illustrative embodiment when read in conjunction
with the accompanying drawings, wherein:
[0033] In the detailed description of various embodiments usable
within the scope of the present disclosure, presented below,
reference is made to the accompanying drawings, in which:
[0034] FIG. 1 depicts a diagram of an embodiment of a system usable
within the scope of the present disclosure.
[0035] FIG. 2A depicts a diagrammatic side view of an embodiment of
a motor engaged with a pump, usable within the scope of the present
disclosure.
[0036] FIG. 2B depicts a diagrammatic side view of an embodiment of
a motor engaged with a pump, usable within the scope of the present
disclosure.
[0037] FIG. 2C depicts a diagrammatic side view of an embodiment of
a motor engaged with a pump, usable within the scope of the present
disclosure.
[0038] FIG. 3 depicts a diagrammatic side view of an embodiment of
a motor engaged with a pump, usable within the scope of the present
disclosure.
[0039] FIG. 4 depicts a diagrammatic side view of an embodiment of
a motor engaged with a pump, usable within the scope of the present
disclosure.
[0040] FIG. 5 depicts a diagrammatic side view of an embodiment of
a VFD usable within the scope of the present disclosure.
[0041] FIG. 6 depicts a diagrammatic view of an embodiment of an
electrical pumping system for supplying fracturing materials to a
formation, usable within the scope of the present disclosure.
[0042] FIG. 7 depicts a diagrammatic view of an embodiment of an
electrical pumping system for supplying fracturing materials to a
formation, usable within the scope of the present disclosure.
[0043] FIG. 8 depicts a diagrammatic view of an embodiment of an
electrical pumping system for supplying fracturing materials to a
formation, usable within the scope of the present disclosure.
[0044] One or more embodiments are described below with reference
to the listed Figures.
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
[0045] Reference now should be made to the drawings, in which the
same reference numbers are used throughout the different figures to
designate the same components.
[0046] Before describing selected embodiments of the present
invention in detail, it is to be understood that the present
invention is not limited to the particular embodiments described
herein. The disclosure and description herein is illustrative and
explanatory of one or more presently preferred embodiments of the
invention and variations thereof, and it will be appreciated by
those skilled in the art that various changes in the design,
organization, order of operation, means of operation, equipment
structures and location, methodology, and use of mechanical
equivalents may be made without departing from the spirit of the
invention.
[0047] As well, it should be understood the drawings are intended
illustrate and plainly disclose presently preferred embodiments of
the invention to one of skill in the art, but are not intended to
be manufacturing level drawings or renditions of final products and
may include simplified conceptual views as desired for easier and
quicker understanding or explanation of the invention. As well, the
relative size and arrangement of the components may differ from
that shown and still operate within the spirit of the invention as
described throughout the present application.
[0048] Moreover, it will be understood that various directions such
as "upper", "lower", "bottom", "top", "left", "right", and so forth
are made only with respect to explanation in conjunction with the
drawings, and that the components may be oriented differently, for
instance, during transportation and manufacturing as well as
operation. Because many varying and different embodiments may be
made within the scope of the inventive concept(s) herein taught,
and because many modifications may be made in the embodiments
described herein, it is to be understood that the details herein
are to be interpreted as illustrative and non-limiting.
[0049] FIG. 1 depicts an embodiment of a system usable to inject a
fluid under pressure into a well (10). For example, the depicted
system can be used to stimulate production (e.g., of hydrocarbons)
by forming fractures in the wellbore formation through the
provision of a pressurized fracturing fluid into the well (10),
mixed with proppant (e.g., solid particulate matter) to maintain
and/or support the fractures while permitting the flow of
hydrocarbons or other fluids from the formation into the wellbore
and toward the surface. Conceptually, FIG. 1 subdivides the
depicted system into a fluid addition subsystem (12) for providing
fracturing fluid to the well (10), a proppant addition subsystem
(14) for providing proppant into the fracturing fluid, a power
subsystem (16) for providing power to one or more components of the
system, and a pumping subsystem (17) for pressurizing fluid for
injection into the well (10). It should be understood that the
number, type, and arrangement of components shown in FIG. 1 is only
one exemplary embodiment, and that the depicted illustration is
diagrammatic, intended to conceptually depict one embodiment of the
present system. As such, it should be noted that any number, type,
and arrangement of identical or similar components could be used
without departing from the scope of the present disclosure.
[0050] The depicted fluid addition subsystem (12) includes a
plurality of tanks (18A, 18B, 18C) and/or other types of vessels
usable to contain one or more fluid media usable as a fracturing
fluid (e.g., to carry proppant to the well (10) and/or to form
fractures in the underlying formation when pressurized).
Specifically, the depicted embodiment includes tanks (18A, 18B,
18C) usable to contain liquid propane, or other low weight alkanes
(e.g., having from one to six carbon atoms); however, it should be
understood that while various embodiments of the present disclosure
can include use of propane and/or other alkanes as a fracturing
fluid, the depicted system, including the proppant addition
subsystem (14) and power subsystem (16), can be used with any type
of fracturing fluid (e.g., water).
[0051] While gelled liquid petroleum gas has been used in
fracturing fluids to minimize damage to formations, driven by
pressure applied using inert gas (e.g., nitrogen), as described in
U.S. Pat. No. 8,408,289, which is incorporated by reference herein,
embodiments usable within the scope of the present disclosure can
include use of liquid propane and/or other alkanes, without the
addition of gellants or other chemical additives. Additionally, to
reduce or eliminate the flammability of the hydrocarbon-based
fracturing fluid, in an embodiment, a halogenated hydrocarbon can
be present. For example, 1,1,1,2,3,3,3-Heptafluoropropane, or a
similar halogenated hydrocarbon compound composed of an aliphatic
or aliphatic derivative (e.g., ethers and/or olefins) with one or
more halogen elements (e.g., fluorine, bromine, etc.) could be
present in the fracturing fluid, such that the resulting fluid is
fire retardant or non-flammable. A portion of the fracturing fluid
could include a halogenated compound while still providing the
fracturing fluid with fire retardant and/or non-flammable
properties, though any quantity of halogenated compounds could be
used without departing from the scope of the present disclosure.
Additionally, it should be understood that heptaafluoropropane is
referenced as an individual exemplary embodiment;
hydrofluoroalkenens, hydrofluoroethers, and other types of
halogenated compounds can also be used without departing from the
scope of the present disclosure. Of note, use of halongenated
hydrocarbons can provide additional beneficial properties beyond
non-flammability, due in part to the higher fluid density and lower
surface tension and viscosity of the halogenated compounds compared
to non-halogenated hydrocarbons
[0052] FIG. 1 depicts the tanks (18A, 18B, 18C) as generally
cylindrical vessels having a vertical orientation. Use of
vertically-oriented tanks to contain propane and/or other alkanes
(and/or halogenated hydrocarbons) can enable gravity and/or vapor
pressure above the contents of the tanks to aid in driving the
contents toward the well (10), thus requiring lower energy and/or
lower power pumping equipment, while also enabling the tanks to
include a smaller quantity of unused volume (e.g., "tank bottoms")
when compared to a horizontally-oriented tank. Vertical tanks also
provide a smaller footprint than horizontal tanks and other
alternatives. However, it should be understood that any type of
vessel usable to contain fracturing fluid can be used without
departing from the scope of the present disclosure. In an
embodiment, the tanks (18A, 18B, 18C) can include multiple outlets
to facilitate flowing of fluid therefrom at a rate sufficient to
perform fracturing or other operations. In a further embodiment,
the tanks (18A, 18B, 18C) can be portable/transportable (e.g.
skid-mounted or otherwise structured to facilitate
transportability) in a generally vertical orientation. In other
embodiments, use of on-site vessels containing fracturing fluid
could be omitted, and pipelines or similar conduits from a remote
source could be used to continuously or intermittently supply
fracturing fluid to the well (10).
[0053] The tanks (18A, 18B, 18C) are shown in communication with a
fluid source (20) for supplying propane and/or other alkanes or
hydrocarbons thereto via a fill line (22). A vent line (24) is also
usable, e.g., to relieve pressure from the tanks (18A, 18B, 18C)
and/or otherwise facilitate flow thereto and therefrom. Each tank
(18A, 18B, 18C) is shown in communication with an associated pump
(26A, 26B, 26C) (e.g., a booster pump), usable to draw fracturing
fluid therefrom and flow the fluid toward the well (10) via a
conduit (28). A secondary fluid booster pump (30) is shown for
further driving the fluid toward the well (10), through a low
pressure region (32) of the conduit. While FIG. 1 depicts each tank
(18A, 18B, 18C) having a respective associated pump (26A, 26B, 26C)
associated therewith, and a secondary booster pump (30) to further
drive the fluid, it should be understood that in various
embodiments, a secondary pump may be omitted, a single pump could
be used to draw fluid from multiple tanks, multiple pumps could be
used to draw fluid from a single tank, or use of pumps could be
omitted. In an embodiment, gravity, vapor pressure, and/or pressure
applied to the tanks (18A, 18B, 18C) and/or the contents thereof
using external sources could be used to drive fracturing fluid
toward the well (10) in lieu of pumps.
[0054] The depicted proppant addition subsystem (14) includes a
plurality of proppant storage vessels (34A, 34B, 34C) (e.g., silos
or another type of tank and/or container), positioned in
association with a conveyor (36), which can include one or more
conveyor belts, chutes, slides, pipes, or other types of conduits
and/or means of conveyance usable to transport proppant from the
vessels (34A, 34B, 34C) toward a hopper (38) or similar type of
container. Use of vertically oriented proppant storage vessels,
such as silos, can enable gravity and/or the weight of the proppant
to drive proppant from the containers toward the conveyor (36)
and/or toward the well (10), while also reducing the footprint
presented by the containers. One exemplary proppant storage
container could include a Model 424 Sand Silo, produced by
Loadcraft Industries, LTD of Brady, Tex., which can include an
associated transportation trailer. Proppant within the vessels
(34A, 34B, 34C) can include any manner of small and/or particulate
solid matter usable to retain and/or support fractures in a
formation, such as sand, glass or clay beads, gravel, or other
similar types of material and or particulate matter, such as
crystalline material (e.g., zircon) and/or hollow glass particles
(e.g., glass bubbles/microspheres, such as those made by 3M of St.
Paul, Minn.), among other possible alternatives.
[0055] While FIG. 1 depicts three proppant storage vessels (34A,
34B, 34C) in association with a conveyor (36) for transporting the
proppant to a hopper (38) or other type of second container, it
should be understood that in various embodiments, a single hopper
or container could be used, while omitting separate storage
containers and a conveyor, or use of a hopper or other type of
secondary container could be omitted while proppant is conveyed
toward the well (10) directly from storage containers. Generally,
the hopper (38) serves as a location where a lubricating fluid from
a lubrication source (40) (e.g., a tank) can be provided to
dispensed proppant, via a conduit (44) and lubrication pump (42).
Usable lubricating fluids can include fracturing fluid identical or
similar to that stored in the tanks (18A, 18B, 18C) of the fluid
addition subsystem (12), mineral oil, or any other suitable
lubricant that is generally non-damaging to system components and
compatible with the fracturing fluid in the tanks (18A, 18B, 18C),
and the formation and reservoir fluids in the well (10). A proppant
pump (45) is usable to drive the proppant and lubricating fluid
toward the well (10) and/or to slurry the proppant with the
lubricating fluid. The proppant is mixed with the flowstream of
fracturing fluid from the fracturing fluid addition subsystem (12)
at an addition point (46) within the low pressure region (32) of
the conduit, such that the flow of the proppant and fracturing
fluid can mix and/or slurry the proppant and fluid (e.g., due to
turbulent flow and/or other factors) to achieve a desired proppant
concentration. Generation of a slurry of proppant and fracturing
fluid having a generally constant proppant concentration enables
the amount of proppant added at the addition point (46) to be
controlled solely by modifying the rate of addition of the proppant
slurry.
[0056] It should be understood that the depicted proppant addition
subsystem (14) is only one exemplary embodiment by which proppant
can be added to a stream of fracturing fluid. In an embodiment, a
venturi nozzle (47) can be positioned in communication with the
flowstream of fracturing fluid, e.g., at or near the addition point
(46) (e.g., upstream thereof), thereby increasing the velocity and
reducing the pressure of fluid at the downstream end of the nozzle
(47), such that the flow of lower-pressure fracturing fluid across
and/or proximate to the addition point (46) can draw proppant
through into the flowstream. A diffuser (49) can be provided
downstream from the nozzle (47). An elastomeric (e.g.,
self-adjusting) nozzle can be used to facilitate a constant
pressure drop across the nozzle, thereby facilitating control of
the rate/concentration of proppant. Use of a venturi nozzle can
further facilitate mixing and/or slurrying of the proppant and
fracturing fluid.
[0057] As fracturing fluid and proppant in the low pressure region
(32) flows toward the well (10) it is pressurized by one or more
high pressure fracturing pumps (70A, 70B, 70C, 70D), defining a
high pressure region (72) of the conduit, such that the fluid
provided into the well (10) is at a pressure sufficient to generate
fractures in the formation. The depicted power subsystem (16) is
usable to provide power to the high pressure pumps (70A, 70B, 70C,
70D), and/or to other system components (such as the pumps (26A,
26B, 26C, 30, 42, 45) usable to flow fracturing fluid, proppant,
and lubricating fluid, the proppant conveyor (36), one or more
valves associated with system components, and/or other similar
elements).
[0058] FIG. 1 illustrates two methods by which the high pressure
pumps (70A, 70B, 70C, 70D) and associated components can be
powered; however, it should be understood that while the depicted
power subsystem (16) includes the simultaneous and/or selective use
of two sources of power, in other embodiments, a single source of
power could be used. Additionally, while the depicted power
subsystem (16) is used to power the high pressure pumps (70A, 70B,
70C, 70D), it should be understood that the power subsystem (16)
can be used to power any portion of the depicted system (e.g., the
booster pumps associated with the fluid subsystem, the lubrication
and slurry pumps associated with the proppant subsystem, proppant
conveyors, various associated valves, as well as other fluid
systems (not shown) associated with the well (10)). Specifically,
the power subsystem (16) is shown having a turbine (52) (e.g., a
natural gas turbine or similar type of device usable to produce
mechanical output from other forms of energy) coupled with a
generator (54), to produce electricity that can be conducted via a
cable (56) or similar conduit to other components of the power
subsystem (16). Alternatively or additionally, power can be
obtained from an external source (e.g., a municipal power grid,
power lines, etc.) (60). While typical electrical power is provided
having a voltage of 4,160, in an embodiment, high voltage lines
could be used to convey electricity to the system. For example,
FIG. 1 depicts power lines (60) capable of conveying high voltage,
e.g., 13,800 volts or more, to a transformer (62), usable to step
down the voltage in the conduit (56) to a typical voltage of 4,160
volts or another usable voltage. Power produced using the generator
(54) can be provided at a usable voltage without requiring a
transformer; however, a transformer could be used in association
with the generator (54) without departing from the scope of the
present disclosure.
[0059] While any number and type of high pressure pumps can be
used, FIG. 1 depicts four high pressure pumps (70A, 70B, 70C, 70D)
usable to pressurize the fracturing fluid. The first and second
high pressure pumps (70A, 70B) are shown positioned on a first
transport vehicle (48A), which can include, by way of example, a
flatbed trailer, a truck, a skid, or any other transportable
platform or framework. Similarly, the third and fourth high
pressure pumps (70C, 70D) are shown positioned on a second
transport vehicle (48B).
[0060] Each transport vehicle (48A, 48B) is shown having a
transformer (64A, 64B) positioned thereon. Use of a transformer on
the vehicle, itself, enables a single respective power cable (58A,
58B) to be extended from the power source to the vehicle (48A,
48B). Conversely, use of a transformer remote from other system
components would require numerous cables and/or other conduits
extending from the transformer to other system components. As such,
positioning of the transformers (64A, 64B) proximate to the high
pressure pumps (70A, 70B, 70C, 70D) and other associated components
minimizes the distance across which large numbers of
cables/conduits must extend. While usable voltages can vary without
departing from the scope of the present disclosure, in an
embodiment, the transformers (64A, 64B) can be adapted to reduce
voltage in the cables (58A, 58B) from 4,160 volts to 600 volts, for
use by components associated with the high pressure pumps (70A,
70B, 70C, 70D). Specifically, FIG. 1 depicts two VFDs (66A, 66B) in
electrical communication with the first transformer (64A), and two
VFDs (66C, 66D) in electrical communication with the second
transformer (64B). The VFDs (66A, 66B, 66C, 66D) each, in turn,
actuate a respective associated electrical motor (68A, 68B, 68C,
68D). Each electrical motor (68A, 68B, 68C, 68D) in turn powers a
respective high pressure pump (70A, 70B, 70C, 70D). In an
embodiment, the electrical motors can include explosion-proof
motors, such as ATEX motors, available from TEC Motors of
Worcestershire, United Kingdom, among other sources.
[0061] To reduce electrical noise/interference, such as when using
a grid-based power source, the transformers (64A, 64B) can be
adapted to convert the received power to a larger number of
successive electrical phases/pulses. For example a transformer
could receive and convert a three-phase source of power to a
nine-phase, eighteen-pulse source of power for transmission to
successive system components.
[0062] As such, the depicted power subsystem (16) is usable to
reduce or eliminate conventional use of diesel engines to power
high pressure fracturing pumps. Additionally, use of modular sets
of components positioned on mobile trailers or similar
transportable vehicles (48A, 48B) minimizes the number and length
of cables and other conduits required to power each component,
while also facilitating installation of each component. For
example, all connections between the transformers (64A, 64B), VFDs
(66A, 66B, 66C, 66D), motors (68A, 68B, 68C, 68D), and high
pressure pumps (70A, 70B, 70C, 70D) can generally be permanently
installed, such that the vehicles (48A, 48B) can be positioned at a
desired location at an operational site, then engaged with a single
cable (58A, 58B), thereby powering each of the components. Further,
use of modular, movable sets of components reduces the footprint of
the system while enabling flexible positioning of components, as
needed, depending on the position of other objects at an
operational site. In an embodiment, power generation components can
be placed remote from other system components, such as the
fracturing fluid addition subsystem (12), which reduces risk of
ignition when flammable components (e.g., propane) are used in the
fracturing fluid.
[0063] While FIG. 1 depicts two transportable vehicles (48A, 48B),
each having one transformer, two VFDs, two electrical motors, and
two high pressure pumps thereon, it should be understood that any
number of transportable vehicles can be used, and further, each
transportable vehicle could include a single high pressure pump or
three or more high pressure pumps without departing from the scope
of the present disclosure. Additionally, while FIG. 1 depicts a
single transformer used in conjunction with two VFDs, two motors,
and two high pressure pumps, any number of transformers could be
used, or in an embodiment, a suitable voltage could be provided to
the components of the power subsystem (16) directly, obviating the
need for transformers on the transportable vehicles. Further, while
FIG. 1 depicts a single VFD used to actuate a single electrical
motor, which in turn powers a single high pressure pump, in various
embodiments, a VFD could actuate multiple motors, multiple VFDs
could be used to actuate a single motor, a single motor could power
multiple high pressure pumps, and/or multiple motors could power a
single high pressure pump.
[0064] Positioning components of the power subsystem (16) in close
proximity to one another, e.g., on transportable vehicles (48A,
48B) can enable other synergistic benefits to be obtained. For
example, in an embodiment, air from one or more blowers used to
cool the electric motors (68A, 68B, 68C, 68D) and/or maintain
positive pressure therein could be channeled to the adjacent high
pressure pumps (70A, 70B, 70C, 70D), e.g., by positioning each
motor and associated high pressure pump in a single housing and/or
connecting the housing of each motor to that of each associated
pump via an air conduit. Air from the blowers could thereby
dissipate/disperse any propane or other alkanes and/or other
flammable materials proximate to the pumps during operation,
thereby preventing accumulation of flammable materials in a
concentration that could be ignited. In one embodiment, the
coupling and/or shaft connecting the motors to respective high
pressure pumps could be provided with fins, blades, and/or other
similar protrusions, such that rotation of the shaft can circulate
air proximate to the high pressure pumps, and/or blower air from
the motors can facilitate rotation of the shaft via the
fins/protrusions by adding rotational motive force thereto.
[0065] For example, FIG. 2A depicts an embodiment of an
electric-powered motor (72) having a blower (74) associated
therewith, typically usable to provide air to the operative and/or
moving parts of the motor (72), e.g., to cool the motor (72),
represented by the air flowpath (76). A drive shaft (80) of the
motor (72) is shown extending therefrom to engage an adjacent pump
(78) (e.g., a high pressure pump usable in fracturing operations).
Rotation and/or other types of movement of the drive shaft (80) as
the motor (72) is powered can thereby actuate the pump (78). An air
conduit (82) is shown extending between the motor (72) and the pump
(78), such that air from the blower (76) can flow through the
conduit (82) to the pump (72), as indicated by the flowpath (84),
e.g., for dissipating gas proximate thereto.
[0066] FIG. 2B depicts an alternate embodiment in which the motor
(72), blower (74), pump (78), and drive shaft (80) are shown. In
the depicted embodiment, an air conduit (86) is circumferentially
disposed around the drive shaft (80), such that air from the blower
(74) that moves across the motor (72), as indicated by the flowpath
(86), can pass through the conduit (86), as indicated by the
flowpath (88), e.g., to dissipate gas proximate to the pump
(78).
[0067] FIG. 2C depicts an alternate embodiment in which the which
the motor (72), blower (74), pump (78), and drive shaft (80) are
shown, contained within a single housing (96). Air from the blower
(74) that passes across the motor (72), as indicated by the
flowpath (76), can thereby also flow proximate to the pump (78), as
indicated by flowpaths (86A, 98B).
[0068] It should be understood that while FIGS. 2A through 2C
depict three possible methods by which air from a blower associated
with a motor can be circulated in proximity to a pump, any method
for conveying air to the pump can be used without departing from
the scope of the present disclosure, and any of the features
depicted in FIGS. 2A through 2C are usable singularly or in
combination.
[0069] FIG. 3 depicts an embodiment in which the motor (72), blower
(74), pump (78), and drive shaft (80) are shown, in which the drive
shaft (80) includes multiple protrusions (90A, 90B) (e.g., fins,
blades, etc.) extending therefrom. Air from the blower (74) can be
provided, e.g., to cool the motor (72), as indicated by flowpath
(76). The air can then flow, as indicated by flowpath (100), to
contact one or more protrusions (90A, 90B), thereby imparting
motive force thereto, and subsequently, to the drive shaft (80),
such that the flow of air can cause additional rotation of the
drive shaft (80), as indicated by the arrows (102A, 102B). While
only two protrusions (90A, 90B) are shown in FIG. 3, any number and
placement/configuration of protrusions can be used without
departing from the scope of the present disclosure. Further, it
should be understood that protrusions extending from the drive
shaft can be used singularly or in combination with any of the
features shown in FIGS. 2A through 2C.
[0070] FIG. 4 depicts an embodiment in which the protrusions (90A,
90B) are themselves usable as an air-moving device. The motor (72),
blower (74), pump (78), and drive shaft (80) are shown, in which
the drive shaft (80) includes multiple protrusions (90A, 90B)
extending therefrom. Movement of the drive shaft (80), e.g.,
imparted by the motor (72), as indicated by arrow (92), can thereby
cause rotation of the protrusions (90A, 90B), which can be
configured and/or oriented to circulate air proximate to the pump
(78), as indicated by the flowpaths (94A, 94B).
[0071] FIG. 5 depicts a diagrammatic side view of an embodiment of
a VFD (104) usable within the scope of the present disclosure. It
should be understood that while a VFD is depicted and described
herein, the concept illustrated in FIG. 5 is usable with any
element of the system depicted in FIG. 1. Specifically, during
operations, it is possible for air at or proximate to the VFD (104)
and/or other system components to become contaminated (e.g., with
volatile gasses when using propane or similar components as a
fracturing fluid, or with other fluids/gasses depending on the
operations being performed). A region of contaminated air (108) is
shown proximate to the top of the VFD (104), while generally clean
air (110) (e.g., lacking contaminants heavier than air) is shown
above the contaminated air (108). During use, it may be necessary
for the VFD (104) to intake air (e.g., for cooling and/or for
operation thereof), while the intake of propane, volatile
components, and/or other contaminants would be undesirable. FIG. 5
depicts an air conduit (106) (e.g., a "snorkel") extending from
and/or otherwise engaged with the VFD (104) for communicating clean
air (110) into the VFD (104), while isolating the VFD (104) from
contaminated air.
[0072] In FIGS. 6-8 the motor/pump combination(s) (X11) comprise
the electric-powered driver (X06) and the pump (X08).
[0073] FIG. 6 depicts a diagrammatic view of an embodiment of an
electrical pumping system (200) for supplying fracturing materials
to a formation, usable within the scope of the present disclosure.
Specifically, FIG. 6 shows an embodiment in which individual VFDs
(204) are used in conjunction with multiple motor/pump combinations
(211) configured to operate at high pressure. As depicted in FIG.
6, multiple systems, in which a single VFD (204) coupled with
multiple motor/pump combinations (211), can be utilized together in
order to flow fracturing materials into a single high pressure
manifold (214), which then supplies the fracturing material to the
formation (216). The embodiment of the electrical system
exemplified in FIG. 6 may be of particular benefit to a fracturing
system in which the flowing of a high volume of fracturing
materials into a formation at low pressure is desired. When the
motor/pump combinations (211) are operating at low pressure, and
therefore do not require a large amount of power to drive, a single
VFD (204) may be used to drive multiple motor/pump combinations
(211) at low pressure without nearing or exceeding its maximum
output capacity. This high-rate, low-pressure system can be
achieved by operating a plurality of motor/pump combinations (211)
with each VFD (204), thereby increasing the number of pumps (208),
and therefore the volume of fracturing material that may be
transported by the system (200) at low pressure at any given
moment.
[0074] FIG. 7 depicts a diagrammatic view of an embodiment of an
electrical pumping system (300) for supplying fracturing materials
to a formation, usable within the scope of the present disclosure.
Specifically, FIG. 7 illustrates an embodiment wherein a single VFD
(304) may be used to drive a single motor/pump combination (311) in
order to allow for the flowing of fracturing materials into a
formation (316) at high pressure. The use of a single VFD (304) for
each motor/pump combination (311) enables the VFD (304) to apply
all of its output capacity to a single motor/pump combination (311)
thereby allowing for the pump (308) to operate at higher pressure
than would be possible if the VFD (304) was configured to split its
output across multiple motor/pump combinations (311) as depicted in
FIG. 6.
[0075] FIG. 8 depicts a diagrammatic view of an embodiment of an
electrical pumping system (400) for supplying fracturing materials
to a formation, usable within the scope of the present disclosure.
Specifically, FIG. 8 shows an embodiment similar to that of FIG. 7,
wherein a single VFD (404) is used to drive a single motor/pump
combination (411); however in the embodiment depicted in FIG. 8 the
VFD (404) is remote from the motor/pump combination (411). The
embodiment depicted in FIG. 8 is ideal for a fracturing project
utilizing volatile fracturing materials, including but not limited
to hydrocarbons, into a formation at high pressure. The
configuration of a single VFD (404) driving a single motor/pump
combination (411) allows for improved high pressure pumping (as
described in the description of FIG. 7). The removal of the VFD
(404) component from physical proximity with the pump (408) and
electrical motor (406) which the VFD (404) is being used to drive
allows for additional safety, especially when the material being
pumped is volatile, at high pressure, or some combination thereof.
By providing physical separation between the VFD (404) and the
volatile and/or high pressure fracturing material being
manipulated, the risks associated with potential ignition sources
are reduced. Specifically, in the event that the fracturing
material is flammable and/or combustible (e.g. liquid propane or
other hydrocarbons) the removal of the VFD (404) from proximity of
the motor/pump combination (411) reduces the risk of the VFD (404)
causing the ignition and/or combustion of any fracturing material
that escapes from the motor/pump combination (411). This may be of
particular importance when the volatile fracturing material is
being pumped at high pressure due to the increased likelihood of
both leaks in the pressure system and aerosolization of the
fracturing material when it transitions from the high pressure
present in the pressure system to the low ambient pressure. This
configuration further allows for the reduction of costs since the
VFD (404) is remote from the area where there is a possibility of
interaction with volatile fracturing materials the VFD (404) itself
would not have to be designed to be protected from the fire or
explosion that could potentially affect the VFD (404) if it were
located proximate to the motor/pump combination (411) that it is
driving.
[0076] While various embodiments usable within the scope of the
present disclosure have been described with emphasis, it should be
understood that within the scope of the appended claims, the
present invention can be practiced other than as specifically
described herein.
* * * * *