U.S. patent application number 16/454670 was filed with the patent office on 2020-01-02 for fracturing pump systems having a hydraulically-driven assembly applying variable amounts of pressure on packing.
The applicant listed for this patent is IMPACT SOLUTIONS AS. Invention is credited to ODDGEIR HUSOY, GEIR KVALSUND SANDNES, TERJE STOKKEV G.
Application Number | 20200003205 16/454670 |
Document ID | / |
Family ID | 67777371 |
Filed Date | 2020-01-02 |
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United States Patent
Application |
20200003205 |
Kind Code |
A1 |
STOKKEV G; TERJE ; et
al. |
January 2, 2020 |
FRACTURING PUMP SYSTEMS HAVING A HYDRAULICALLY-DRIVEN ASSEMBLY
APPLYING VARIABLE AMOUNTS OF PRESSURE ON PACKING
Abstract
A fracturing pump system includes a fluid end having a cylinder
and a piston movable to pressurize fluid in the cylinder. The
cylinder has at least one cylinder sidewall, packing located to
prevent fluid from leaking between the piston and the cylinder
sidewall, and a hydraulically-driven assembly configured to apply
variable amounts of pressure on the packing.
Inventors: |
STOKKEV G; TERJE;
(Ulsteinvik, NO) ; HUSOY; ODDGEIR; (Fosnavaag,
NO) ; SANDNES; GEIR KVALSUND; (Tjoervaag,
NO) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
IMPACT SOLUTIONS AS |
Ulsteinvik |
|
NO |
|
|
Family ID: |
67777371 |
Appl. No.: |
16/454670 |
Filed: |
June 27, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62690623 |
Jun 27, 2018 |
|
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|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04B 15/02 20130101;
F04B 49/08 20130101; E21B 43/26 20130101; F04B 53/02 20130101; F04B
49/02 20130101; F04B 2205/18 20130101; F04B 53/164 20130101; F04B
53/18 20130101 |
International
Class: |
F04B 49/08 20060101
F04B049/08; F04B 15/02 20060101 F04B015/02; F04B 49/02 20060101
F04B049/02; F04B 53/18 20060101 F04B053/18; E21B 43/26 20060101
E21B043/26 |
Claims
1. A fracturing pump system, comprising: a fluid end having a
cylinder and a piston movable to pressurize fluid in the cylinder;
the cylinder having at least one cylinder sidewall; packing located
to prevent fluid from leaking between the piston and the at least
one cylinder sidewall; and a hydraulically-driven assembly
configured to apply variable amounts of pressure on the
packing.
2. The fracturing pump system of claim 1, wherein the
hydraulically-driven assembly comprises: a hydraulic supply
containing hydraulic fluid; a hydraulic assembly for interacting
with the packing, the hydraulic assembly comprising: a hydraulic
assembly piston for imparting pressure on the packing, the
hydraulic assembly piston being movable toward and away from the
packing; and a passage from the hydraulic supply to the hydraulic
assembly piston; and a control system for adjusting position of the
hydraulic assembly piston and thereby adjusting pressure on the
packing, the control system comprising: non-transitory computer
memory; a processor in data communication with the computer memory;
a sensor in data communication with the processor; a pump in data
communication with the processor and in fluid communication with
the hydraulic supply; a valve for selectively allowing the
hydraulic assembly piston to move away from or towards the packing;
and programming stored in the computer memory that, when executed
by the processor, causes the processor to: (a) utilize data from
the sensor to determine a desired amount of hydraulic control
pressure to be applied to the hydraulic assembly piston; and (b)
actuate the pump to selectively allow the hydraulic assembly piston
to move toward or away from the packing using the hydraulic fluid
in the hydraulic supply.
3. The fracturing pump system of claim 2, wherein pressure in the
fluid end ranges from 0 psi to at least 10,000 psi.
4. The fracturing pump system of claim 3, wherein the fluid
pressurized in the cylinder is an abrasive slurry.
5. The fracturing pump system of claim 4, further comprising a
power system outputting reciprocating motion to operate the piston
in the cylinder.
6. The fracturing pump system of claim 5, wherein the power system
includes at least one item selected from the group consisting of a
reciprocating engine, an electric motor, and a gas turbine.
7. The fracturing pump system of claim 2, further comprising
programming stored in the computer memory that, when executed by
the processor, causes the processor to: (c) determine a remaining
lifespan of at least one sacrificial component.
8. The fracturing pump system of claim 7, further comprising
programming stored in the computer memory that, when executed by
the processor, causes the processor to: (d) automatically stop the
piston from pressurizing fluid in the cylinder upon detecting a
failure event meeting a threshold warning level.
9. The fracturing pump system of claim 8, wherein the threshold
warning level includes at least one item selected from the group
consisting of: a threshold pressure, a threshold block temperature,
a threshold fluid temperature, a threshold vibration, and a fluid
bypass occurrence.
10. The fracturing pump system of claim 2, wherein the sensor is at
least one item selected from the group consisting of a temperature
sensor, a pressure sensor, an optical sensor, a counter, a
fluid-level sensor, and a vibration sensor.
11. The fracturing pump system of claim 2, further comprising
programming stored in the computer memory that, when executed by
the processor, causes the processor to: (c) determine condition of
at least one component of the fracturing pump system.
12. The fracturing pump system of claim 11, further comprising
programming stored in the computer memory that, when executed by
the processor, causes the processor to: (d) automatically stop the
piston from pressurizing fluid in the cylinder upon detecting an
event meeting a threshold warning level.
13. The fracturing pump system of claim 2, further comprising a
lubricant and a lubricating pump for supplying the lubricant to the
packing, and wherein the control system measures pressure
associated with the lubricant and alters operation of the
lubricating pump based on the measured pressure.
14. The fracturing pump system of claim 2, further comprising a
lubricant and a lubricating pump for supplying the lubricant to the
packing, and wherein: the control system measures at least one
characteristic associated with at least one item selected from the
group consisting of the lubricant and the lubricating pump; and the
control system alters operation of the lubricating pump based on
the measured characteristic.
15. A system for pumping abrasive slurry, comprising: a fluid end
having a cylinder and a piston movable to pressurize an abrasive
slurry in the cylinder; the cylinder having at least one cylinder
sidewall; packing located to prevent the abrasive slurry from
leaking between the piston and the at least one cylinder sidewall;
and a hydraulically-driven assembly configured to apply variable
amounts of pressure on the packing; wherein the
hydraulically-driven assembly comprises: (i) a hydraulic supply
containing hydraulic fluid; (ii) a hydraulic assembly for
interacting with the packing, the hydraulic assembly comprising: a
hydraulic assembly piston for imparting pressure on the packing,
the hydraulic assembly piston being movable toward and away from
the packing; and a passage from the hydraulic supply to the
hydraulic assembly piston; and (iii) a control system for adjusting
a position of the hydraulic assembly piston and thereby adjusting
pressure on the packing, the control system comprising:
non-transitory computer memory; a processor in data communication
with the computer memory; a sensor in data communication with the
processor; a pump in data communication with the processor and in
fluid communication with the hydraulic supply; a valve in data
communication with the processor for selectively allowing the
hydraulic assembly piston to move away from the packing; and
programming stored in the computer memory that, when executed by
the processor, causes the processor to: (a) utilize data from the
sensor to determine a desired amount of hydraulic control pressure
to be applied to the hydraulic assembly piston; and (b) actuate at
least one of the pump and the valve to apply and regulate the
desired amount of hydraulic control pressure to the hydraulic
assembly piston using the hydraulic fluid in the hydraulic
supply.
16. The system of claim 15, further comprising programming stored
in the computer memory that, when executed by the processor, causes
the processor to: (c) determine a remaining lifespan of at least
one sacrificial component.
17. The system of claim 15, further comprising programming stored
in the computer memory that, when executed by the processor, causes
the processor to: (c) determine condition of at least one component
of the system.
18. The system of claim 17, further comprising programming stored
in the computer memory that, when executed by the processor, causes
the processor to: (d) automatically stop the piston from
pressurizing the abrasive slurry in the cylinder upon detecting an
event meeting a threshold warning level.
19. The system of claim 18, further comprising a lubricant and a
lubricating pump for supplying the lubricant to the packing, and
wherein: the control system measures at least one characteristic
associated with at least one item selected from the group
consisting of the lubricant and the lubricating pump; and the
control system alters operation of the lubricating pump based on
the measured characteristic.
20. A method for automatically adjusting pressure applied to
packing within a fracturing pump system, comprising: providing a
fracturing pump system comprising: a fluid end having a cylinder
and a piston movable to pressurize fluid in the cylinder, the
cylinder having at least one cylinder sidewall; packing located at
the cylinder sidewall to prevent fluid from leaking between the
piston and the at least one cylinder sidewall; and a
hydraulically-driven assembly configured to apply variable amounts
of pressure on the packing, the hydraulically-driven assembly
comprising: a hydraulic assembly piston for imparting hydraulic
control pressure on the packing, the hydraulic assembly piston
being movable toward and away from the packing; and a passage from
the hydraulic supply to the hydraulic assembly piston; providing a
control system comprising a processor in data communication with: a
sensor; a pump in fluid communication with the hydraulic supply;
and a valve for selectively allowing the hydraulic assembly piston
to move away from the packing; activating the sensor to determine a
first attribute of the fracturing pump system; determining, via the
processor, a first hydraulic control pressure based on the first
attribute of the fracturing pump system; actuating at least one of
the pump and the valve to apply and regulate the hydraulic control
pressure based on the first hydraulic control pressure; activating
the sensor to determine a second attribute of the fracturing pump
system; determining, via the processor, a second hydraulic control
pressure based on the second attribute of the fracturing pump
system; and actuating at least one of the pump and the valve to
apply and regulate the hydraulic control pressure based on the
second hydraulic control pressure.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent
Application No. 62/690,623, filed Jun. 27, 2018, the disclosure of
which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The current disclosure relates generally to stuffing boxes
and to fracturing pump systems using stuffing boxes. A stuffing box
is typically a device using packing to seal a rotating or
reciprocating shaft against a fluid.
SUMMARY OF THE INVENTION
[0003] The following presents a simplified summary of the invention
in order to provide a basic understanding of some aspects of the
invention. The summary is not an extensive overview of the
invention. It is not intended to identify critical elements of the
invention or to delineate the scope of the invention. Its sole
purpose is to present some aspects of the invention in a simplified
form as a prelude to the more detailed description that is
presented elsewhere herein.
[0004] According to one embodiment, a fracturing pump system
includes a fluid end having a cylinder and a piston movable to
pressurize fluid in the cylinder. The cylinder has at least one
cylinder sidewall, packing located to prevent fluid from leaking
between the piston and the cylinder sidewall, and a
hydraulically-driven assembly configured to apply variable amounts
of pressure on the packing.
[0005] In one aspect, the hydraulically-driven assembly has a
hydraulic supply containing hydraulic fluid; a hydraulic assembly,
and a passage from the hydraulic supply to the hydraulic assembly.
The hydraulic assembly includes a hydraulic assembly piston for
imparting pressure on the packing, and is movable toward and away
from the packing. More particularly, the passage runs from the
hydraulic supply to the hydraulic assembly piston. The fracturing
pump system further includes a control system for adjusting
position of the hydraulic assembly piston and thereby adjusting
pressure on the packing. The control system includes non-transitory
computer memory; a processor in data communication with the
computer memory; a sensor in data communication with the processor;
a pump in data communication with the processor and in fluid
communication with the hydraulic supply; a valve for selectively
allowing the hydraulic assembly piston to move away from the
packing; and programming stored in the computer memory. The
programming, when executed by the processor, causes the processor
to: (a) utilize data from the sensor to determine a desired amount
of hydraulic control pressure to be applied to the hydraulic
assembly piston; and (b) actuate the pump to selectively allow the
hydraulic assembly piston to move toward or away from the packing
using the hydraulic fluid in the hydraulic supply.
[0006] According to some aspects, pressure in the fluid end ranges
from 0 psi to at least 10,000 psi. According to further aspects,
the fluid pressurized in the cylinder is an abrasive slurry. In
still further aspects, the fracturing pump system further includes
a power system outputting reciprocating motion to operate the
piston in the cylinder. The power system includes at least one item
selected from the group consisting of a reciprocating engine, an
electric motor, and a gas turbine.
[0007] According to yet another aspect of the invention, the
fracturing pump system further has programming stored in the
computer memory that, when executed by the processor, causes the
processor to: (c) determine a remaining lifespan of at least one
sacrificial component. In still yet another aspect, the fracturing
pump system further comprises programming stored in the computer
memory that, when executed by the processor, causes the processor
to: (d) automatically stop the piston from pressurizing fluid in
the cylinder upon detecting a failure event meeting a threshold
warning level. In some aspects, the threshold warning level
includes at least one item selected from the group consisting of: a
threshold pressure, a threshold block temperature, a threshold
fluid temperature, a threshold vibration, and a fluid bypass
occurrence.
[0008] According to further aspects, the sensor is at least one
item selected from the group consisting of a temperature sensor, a
pressure sensor, an optical sensor, a counter, a fluid-level
sensor, and a vibration sensor.
[0009] In still further aspects of the invention, the fracturing
pump system includes programming stored in the computer memory
that, when executed by the processor, causes the processor to: (c)
determine condition of at least one component of the fracturing
pump system. The fracturing pump system may additionally further
include programming stored in the computer memory that, when
executed by the processor, causes the processor to: (d)
automatically stop the piston from pressurizing fluid in the
cylinder upon detecting an event meeting a threshold warning
level.
[0010] In some aspects, the fracturing pump further includes a
lubricant and a lubricating pump for supplying the lubricant to the
packing, and wherein the control system measures pressure
associated with the lubricant and alters operation of the
lubricating pump based on the measured pressure.
[0011] In still other aspects, the fracturing pump system has a
lubricant and a lubricating pump for supplying the lubricant to the
packing. The control system measures at least one characteristic
associated with at least one item selected from the group
consisting of the lubricant and the lubricating pump and
subsequently alters operation of the lubricating pump based on the
measured characteristic.
[0012] According to another embodiment, a system for pumping
abrasive slurry has a fluid end having a cylinder and a piston
movable to pressurize an abrasive slurry in the cylinder. The
cylinder has at least one cylinder sidewall. Packing is located to
prevent the abrasive slurry from leaking between the piston and the
at least one cylinder sidewall. A hydraulically-driven assembly is
configured to apply variable amounts of pressure on the packing.
The hydraulically-driven assembly includes: (i) a hydraulic supply
containing hydraulic fluid; (ii) a hydraulic assembly for
interacting with the packing; and (iii) a control system. The
hydraulic assembly includes a hydraulic assembly piston to impart
pressure on the packing, and is movable toward and away from the
packing; and a passage from the hydraulic supply to the hydraulic
assembly piston. The control system adjusts a position of the
hydraulic assembly piston and thereby adjusting pressure on the
packing. The control system includes non-transitory computer
memory; a processor in data communication with the computer memory;
a sensor in data communication with the processor; a pump in data
communication with the processor and in fluid communication with
the hydraulic supply; a valve in data communication with the
processor for selectively allowing the hydraulic assembly piston to
move away from the packing; and programming stored in the computer
memory that, when executed by the processor, causes the processor
to: (a) utilize data from the sensor to determine a desired amount
of hydraulic control pressure to be applied to the hydraulic
assembly piston; and (b) actuate at least one of the pump and the
valve to apply and regulate the desired amount of hydraulic control
pressure to the hydraulic assembly piston using the hydraulic fluid
in the hydraulic supply.
[0013] In some aspects, the system further includes programming
stored in the computer memory that, when executed by the processor,
causes the processor to: (c) determine a remaining lifespan of at
least one sacrificial component.
[0014] In other aspects, the system further includes programming
stored in the computer memory that, when executed by the processor,
causes the processor to: (c) determine condition of at least one
component of the system.
[0015] In still other aspects, the system further includes
programming stored in the computer memory that, when executed by
the processor, causes the processor to: (d) automatically stop the
piston from pressurizing the abrasive slurry in the cylinder upon
detecting an event meeting a threshold warning level.
[0016] According to still further aspects of the invention, the
system further has a lubricant and a lubricating pump for supplying
the lubricant to the packing. The control system measures at least
one characteristic associated with at least one item selected from
the group consisting of the lubricant and the lubricating pump and
subsequently alters operation of the lubricating pump based on the
measured characteristic.
[0017] According to yet another embodiment of the invention, a
method for automatically adjusting pressure applied to packing
within a fracturing pump system, includes providing a fracturing
pump system and a control system, and using the control system to
operate the fracturing pump system. More particularly, the
fracturing pump system includes a fluid end having a cylinder and a
piston movable to pressurize fluid in the cylinder, the cylinder
having at least one cylinder sidewall; packing located at the
cylinder sidewall to prevent fluid from leaking between the piston
and the at least one cylinder sidewall; and a hydraulically-driven
assembly configured to apply variable amounts of pressure on the
packing. The hydraulically-driven assembly has a hydraulic assembly
piston, movable toward and away from the packing, for imparting
hydraulic control pressure on the packing; and a passage from the
hydraulic supply to the hydraulic assembly piston. The control
system includes a processor in data communication with: a sensor; a
pump in fluid communication with the hydraulic supply; and a valve
for selectively allowing the hydraulic assembly piston to move away
from the packing.
[0018] The sensor is activated to determine a first attribute of
the fracturing pump system. Then, a first hydraulic control
pressure is determined based on the first attribute of the
fracturing pump system. At least one of the pump and the valve is
actuated to apply and regulate the hydraulic control pressure based
on the first hydraulic control pressure. The sensor is again
activated to determine a second attribute of the fracturing pump
system. A second hydraulic control pressure is determined based on
the second attribute of the fracturing pump system. Finally, at
least one of the pump and the valve is actuated to apply and
regulate the hydraulic control pressure based on the second
hydraulic control pressure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a section view of a PRIOR ART fluid end design
incorporating a manual packing nut and associated seal
assembly.
[0020] FIG. 2 is a perspective view of a PRIOR ART packing nut.
[0021] FIG. 3 is a section view of a PRIOR ART packing nut and seal
assembly.
[0022] FIG. 4 is a perspective view of a PRIOR ART packing nut
showing an oil or grease journal for delivering lubrication to the
packing and seal faces.
[0023] FIG. 5 is a section view of a PRIOR ART packing nut together
with an oil or grease journal for injecting lubricant into the
packing assembly.
[0024] FIG. 6 is a section view of a hydraulically actuated
stuffing box according to an embodiment of the invention.
[0025] FIG. 7 is a schematic of a control system according to an
embodiment of the invention.
DETAILED DESCRIPTION
[0026] Hydraulic fracturing pump systems include a power system and
a fluid end. The power system typically includes an engine (for
example, a diesel or other reciprocating engine, an electric motor,
a gas turbine, et cetera), a transmission, and a power end, and the
power end in turn includes a crankshaft, reduction gears, bearings,
connecting rods, crossheads, crosshead extension rods, and other
elements to convert rotational energy from the engine to
reciprocating energy. The fluid end is typically a reciprocating
high-pressure pump that is driven by reciprocating motion from the
power system (and specifically the power end). FIG. 1 shows a
section view of a typical prior art fluid end 10.
[0027] The fluid end produces very high pressures and flow rates
with abrasive fluids for fracking operations, and includes sections
where fluid is imported through a suction manifold into a central
cylinder and discharged through a discharge manifold. There are
typically multiple inner chambers (or "cylinders") arranged
side-by-side to form triplex or quintuplex pumps. A reciprocating
piston 18 acts in each chamber to pressurize the fluid. More
particularly, typical fluid end assemblies usually include a
housing such as a machined steel block that has: a plurality of
suction bores each having a suction valve 20 and seat 22; discharge
bores each having a discharge valve 24 and seat 26; access ports 30
to enable ease of installation of various components; plunger bores
each having a plunger 18 (i.e., piston) and packing seal assembly
32; high-pressure seals 33 and retainers; and other standard
elements. The various valves, seals, and plungers control the flow
of fracking fluids entering and leaving the fluid end housing from
the low-pressure side and the high-pressure side. Safety relief
systems for fluid bypass, when present in the prior art, are
typically limited to mechanical pop off or burst disk
configurations. More particularly, high pressure relief valves
(e.g., pop off or burst disc valves) may be mounted externally on
the high-pressure fluid side of the fluid end to relieve fracturing
fluid pressure and volume to atmospheric conditions if an
over-pressure event occurs.
[0028] Operating fracking fluid pressure often varies between
0-10,000 psi and can be up to, for example, 15,000 psi. When fluid
temperatures and metal temperatures change, the pressures on the
seals and seal faces change due to expansion or contraction. The
cyclic nature, high pressure, and high fluid rates combined with
the chemical and very abrasive characteristics of the fracking
slurry result in highly erosive--and high stress--operating
environment. There is high risk of washing of materials (erosion)
in the seal areas, plunger faces, and fluid end materials which may
result in catastrophic failure of the fluid end bodies and assorted
assemblies. The valves, seats, plungers, packing seal assemblies,
and access bore seals are thus generally classified as expendable
elements that fail frequently due, for example, to abrasion and
cyclic fatigue.
[0029] The plunger 18 and packing seal assemblies 32 in the plunger
bores are typically installed and retained by threaded packing nuts
34 that are mechanical in nature, and that are manually set and
adjusted. Prior art packing nuts 34a, 34b, 34c, and 34d are shown
in FIGS. 2 through 5. The packing nuts 34 apply force on the
packing assemblies 32 and packing seals 33, and the packing nuts 34
and fluid end bodies have journals 35 (FIG. 4) that are connected
to an exterior lubricant pump. The lubricant pump injects or
supplies oils and/or grease through the journals to the packings
for the purpose of lubricating and cooling the various seal faces.
The purpose of the packing seals is to control (e.g., by
retaining/containing) the high-pressure fluids while the plungers
and reciprocating members move to pressurize the fluids. In other
words, the packing seals 33 and assemblies 32 stop high pressure
fluids from leaking to atmospheric condition while allowing the
plungers 18 to reciprocate. The packing seals 33 are installed
within the cylinder bores and around the plungers 18. The packing
nuts 34 are threaded into the fluid end body cylinder bores and
around the plungers to secure the packing seals in place, and apply
pressure on the seals to cause sealing.
[0030] During assembly the packing nuts 34 are first seated on the
packing assemblies 32, and then turned (i.e., rotated) in order to
apply force and compress the seals 33 between the fluid end body 11
and the reciprocating plungers 18. The packing nuts 34 mechanically
apply pressure based on rotation and applied torque, compressing
the seals 33 and the seal assemblies 32. Pressure is traditionally
applied by observation and feel, and is generally not calibrated or
accurately quantifiable in nature. In other words, the amount of
compression or torque applied to the packing nuts 34 is
traditionally not applied by a measurable, recordable, and
monitorable form--there is no capability to measure any parameters
associated with the performance of the sealing assemblies 32 (for
example, set forces, set pressures, hydraulic pressures, hydraulic
volumes, torque, specific turns, applied pressures, et cetera),
either intermittently or real-time, related to the amount of force
being applied on the seals 33 by the packing nut 34, or to indicate
wear or condition, other than to visually observe for leaks and
manually test for tightness using a hand tool or hand wrench. To
complicate the issue, checking seals 33 and seal assembly 32
conditions visually typically requires substantial disassembly,
which in turn results in operational down time and labor costs.
[0031] Nevertheless, in prior art systems, the design,
configuration, operational assembly, and setting of the packing
nuts 34 and packing seal assemblies 32 is installed and configured
for maximum containment of fracturing fluids and pressures, which
are often 10,000 psi or more. This means that the stress and wear
points for the bodies, packings, assemblies, and pistons are
positioned and set to maximum forces associated with achieving
maximum containment in order to contain the maximum pressures
within the fluid end. As such, they are always in a maximum state
of wear and stress. During operations, the packing nuts 34 and
packing seal assemblies 32 loosen with wear and vibration, and then
are adjusted intermittently after some sequence of operational
events that indicates tightening may be required. Operations
personnel perform these intermittent adjustments over unspecified
time intervals based on general knowledge and practices, operating
environments, and parameters indicating to tighten, which may
include, for example, a predetermined volume of fluid pumped, a
predetermined number of stages performed, a predetermined number of
strokes (as counted by stroke counters, for example), and visual
indications of leaking. While some prior assemblies may have a form
of locking or stabilizing fixtures to inhibit movement due to
vibrations, the assemblies are nevertheless subject to loosening
because of vibrations, wears, and compaction of seals--causing
operations personnel to ultimately retighten the assemblies by hand
back to some unspecified torque.
[0032] Additionally, prior art systems lack sensors associated with
the packing assemblies 32 for providing information about the
performance, state, or condition of the assemblies, and there is no
measure of the performance of the lubricating pump, the volume at
which it is pumping, or the pressures it is injecting at.
[0033] FIG. 6 shows part of new fracturing pump systems 100. In the
new embodiments, the mechanical packing nuts and packing assemblies
used to adjust the packing seals in the fluid end of traditional
systems are omitted. Instead, a pressure-compensating assembly 140
that is hydraulically driven is included to apply pressure to the
seals 152 in a variable manner, compensating for changes in wear,
temperatures, and pressure dynamics. More particularly, the
traditional packing nut 34 is replaced with an assembly 140 having
pressure chambers, seals, and hydraulic pistons which are used to
apply pressure to (and thereby energize) packing seals 152.
Pressure is applied in linear compression, without rotation. This
eliminates the rotational moments that are historically required
when changing or adjusting the applied pressures to packing
assemblies in fracturing pump systems.
[0034] Within the new fracturing pump systems 100, focus is
directed to three primary component systems: a hydraulic assembly
and sealing mechanisms used to energize the seals; a hydraulic
supply used to regulate and apply pressure to the hydraulic
assembly; and control and sensor systems that in real time adjust
the hydraulic pressures applied to energize the packing seals as
well as lubrication supplied to these seals. These component
systems may be incorporated into the fluid end 111 of the
fracturing pump systems 100, and/or into the power system of the
fracturing pump systems. In the fluid ends 111, where fluids and
fluid mixtures typically range from 0 psi to 10,000 psi or more,
and where there are often extreme, heavy duty operating
environments due to the pressures and pumping of fluids and the
chemical and erosive nature of the pumped materials, these
component systems may advantageously control the pressures applied
to packing seals 152 and contain high pressure fluids. In the power
systems, these components may be used with the power source, gear
box, hydraulic drive, et cetera. For purposes of illustration, the
new fluid ends are described in additional detail. The terms "seal"
and "packing" are used interchangeably herein to refer to a device
designed to isolate fluid and/or pressure.
[0035] The fluid end configuration 111 in the new fracturing pump
systems 100 in purpose and function remain the same as in the
design of prior designs. But the manual packing nuts and associated
seal assembly systems are replaced by the hydraulically controlled,
actuated, and operated piston assembly 140, described in greater
detail below, which applies force to the packing seal assemblies
and seals based on the hydraulic pressures applied.
[0036] As with traditional systems, in the fracturing pump system
100, packing brass 150 surrounds the plunger 118, and packing 152
is provided within the packing brass 150. Pressure is applied to
the packing 152 via the hydraulically operated piston assembly 140.
The hydraulically operated piston assembly 140 includes a gland nut
142 that surrounds the piston 118 of the fracturing pump system,
and specifically, the fluid end 111. Hydraulic fluid seals 144
within the gland nut 142 prevent hydraulic fluid from escaping from
the gland nut 142. A hydraulically operated piston 143 within the
gland but 142 is in communication with hydraulic line 141 and is
operable to apply pressure to the packing 152. Hydraulic piston
seals 145 surround the piston 142 to prevent hydraulic fluid from
flowing across the piston head. In operation, hydraulic fluid flows
from the hydraulic line 141, causing the piston 143 to apply
pressure to the packing brass 150, and therefore the packing 152.
As will be described in greater detail below, the operation of the
hydraulically operated piston assembly 140 for applying pressure to
the packing 152 may be automated via a control system 200 (FIG.
7).
[0037] A packing lubrication line 160 may be accessible via the
fluid end 111. The lubrication line 160 runs to the packing 152,
allowing the seals 152 to receive lubrication as needed. One or
more sensors 170 (e.g., temperature sensors and/or other sensors)
within the fluid end 111 measure various characteristics associated
with the piston assembly 140, and communicate with the control
system 200 to control the hydraulic pressure to the packing 152 in
order to maximize life of the assembly 140 and at the same time
maintain the desired operating pressure for the pump. The
lubrication line 160 may additionally be controlled via the control
system.
[0038] The control system 200 manages the hydraulic control
pressure (HCP) that is applied to the hydraulic sealing assembly
140 via the hydraulic line 141 and thus to the seal (packing) 152.
The control system also manages the lubrication supply system 160.
Referring now to FIG. 7, the control system 200 broadly includes a
non-transitory computer memory 205, a processor 210 in data
communication with the computer memory, at least one input device
215 (e.g., sensor 170) in data communication with the processor
210, a pump 220 in data communication with the processor 210, and
control valves 225 in data communication with the processor 210;
the pump 220 is in fluid communication with the hydraulic supply
141 used to regulate and apply pressure to the hydraulic assembly
140.
[0039] The control system 200 is variable, recorded, and adjusted
real time through computer-based algorithms 207 (stored in the
computer memory 205) to maintain optimal HCP for keeping the
packing 152 from undesirably leaking. The HCP may be selected based
on factors such as, for example, sealing surface area, seal type,
seal material, seal life, pressure to be contained, pressure
applied, and the relationship(s) between such factors. It may be
particularly desirable for the HCP to maintain a minimum
differential pressure required between the fluid pressure to be
contained within the fracking pump and the pressure to be applied
to the seals 152, as this may maximize component performance, life,
and sealing capabilities.
[0040] The relationship between the fluid pressures being contained
and the positive pressure required on the seal faces to contain
that pressure is controlled, managed, and established automatically
by varying the HCP as desired (i.e., by actuating/deactuating the
pump 220 and the control valve(s) 225). In addition, manual
settings may be included to supplement or override the automatic
control of the HCP. Merely as examples, the control system 200 may
determine that 1,000 psi fluid pressure in the fluid end of a given
fracking-pump system may correlate to a desired HCP of 1,100 psi;
or that 2,000 psi fluid pressure correlates to a desired HCP of
2,300 psi. Yet even in those given fracking-pump systems, the HCP
may vary over time at those fluid end pressures to account for such
things as chemical reactivity, erosion, wear, vibration,
compaction, temperature, et cetera, so the example HCP values
should be seen as temporary (and not permanent). As merely an
example, the pumped materials may chemically react with the seals
152, causing degradation and affecting the HCP. It may be desirable
for the control system 200 to be capable of modulating HCP to match
fluid end pressures from 0 psi to at least 10,000 psi, and more
preferably to at least 15,000 psi.
[0041] The input device(s) 215 (e.g., sensor 170) in the control
system 200 may measure, for example, pressure in the fluid end 111,
HCP, volume of fluid, pressure and/or injection rate of the
lubricating pump, number of cycles, optical conditions,
temperature, vibration, and other parameters, and the processor 210
may use the data from the sensors 170 and the algorithms 207 in the
computer memory 205 to automatically adjust the HCP (via pump 220)
and/or the operation of a lubricating pump 230 as needed. The
processor 210 may further determine the remaining life of the
packing 152 and other components (and especially, but not limited
to, sacrificial components), ultimately extending the life of the
fluid end 111 and its systems. Thus, when wear occurs to the seals
or surfaces, the movement and change can be identified. And changes
of temperature, volume, or pressure may indicate traits regarding
packing life, condition, and competence to continue sealing.
[0042] The new fracturing pump systems 100 may have extended
packing lifespans since the packing 152 is maintained in an optimal
(or near-optimal, or at least desirable) state, and not subjected
to excessive forces or over pressured, which result in premature
wear or failure. If the packing 152 does leak (i.e., fluid bypass
occurs), it can be identified from various changes in pressure,
temperature, and volume, and the control system may automatically
stop operation of the fracturing pump system 100 (or parts of the
system, as it may be possible in some embodiments to stop
cylinders, for example, and to continue operations with remaining
cylinders). Therefore, the risk of high pressure fluid releases may
be reduced, safety may be improved, and component life may be
increased. For example, sensing a change in HCP may be due to
bypass of fluid pressure or hydraulic control fluids, indicating
seal failure; sensing a change in oil temperature or in block
temperature in the seal regions or elsewhere may indicate the
presence of increased friction pressures from increased wear or
premature failure of components; sensing a change in HCP piston
forces may indicate fluid bypass or surface washouts; sensing an
increase in HCP above a threshold may indicate fluid bypass;
sensing bypass of fluids between the seals and the fluid end bodies
may indicate poor seal performance, failure of seal, or washout of
fluid end body materials; sensing bypass of fluids between the
seals and the reciprocating pistons may indicate seal performance
failure or wash of the piston seal faces; sensing bypass around
seals may indicate metal erosion; sensing a change in vibration may
indicate fluid bypass; et cetera. These active, automatic control
features are not possible in the prior art systems having
manually-adjusted packing nuts. Moreover, the control system may
allow remote monitoring, improving the site and operating safety
since the need to enter into the hazardous high-pressure zones and
the risks associated with entering therein during operations is
reduced or eliminated.
[0043] In some embodiments, the new fracturing pump systems 100 are
constructed with the hydraulically-driven pressure-compensating
assemblies (including the component systems). In other embodiments,
the new fracturing pump systems are constructed by removing the
mechanical packing nuts and packing assemblies used to adjust the
packing seals and adding the hydraulically-driven
pressure-compensating assemblies (including the component
systems).
[0044] Many different arrangements of the various components
depicted, as well as components not shown, are possible without
departing from the spirit and scope of the invention. Embodiments
of the invention have been described with the intent to be
illustrative rather than restrictive. Alternative embodiments will
become apparent to those skilled in the art that do not depart from
its scope. A skilled artisan may develop alternative means of
implementing the aforementioned improvements without departing from
the scope of the disclosure presented herein. It will be understood
that certain features and subcombinations are of utility and may be
employed without reference to other features and subcombinations
and are contemplated within the scope of the claims. The specific
configurations and contours set forth in the accompanying drawings
are illustrative and not limiting.
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