U.S. patent application number 15/936257 was filed with the patent office on 2018-08-02 for gel hydration unit.
The applicant listed for this patent is ADVANCED STIMULATION TECHNOLOGY, INC.. Invention is credited to DONALD OLDHAM.
Application Number | 20180214829 15/936257 |
Document ID | / |
Family ID | 48572533 |
Filed Date | 2018-08-02 |
United States Patent
Application |
20180214829 |
Kind Code |
A1 |
OLDHAM; DONALD |
August 2, 2018 |
GEL HYDRATION UNIT
Abstract
A fracking fluid hydration unit is provided that has a plurality
of hydration tank sections wherein shear is added to the hydrated
fluid flow via a recirculation hydrated fluid jetting system.
Inventors: |
OLDHAM; DONALD; (MIDLAND,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ADVANCED STIMULATION TECHNOLOGY, INC. |
MIDLAND |
TX |
US |
|
|
Family ID: |
48572533 |
Appl. No.: |
15/936257 |
Filed: |
March 26, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14546358 |
Nov 18, 2014 |
9981231 |
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15936257 |
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13316159 |
Dec 9, 2011 |
8899823 |
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14546358 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B01F 3/12 20130101; B01F
5/0212 20130101; B01F 3/1271 20130101; B01F 5/10 20130101; B01F
5/12 20130101; B01F 2215/0081 20130101; C09K 8/68 20130101; B01F
5/0606 20130101; C09K 8/62 20130101; B01F 5/0206 20130101; B01F
5/106 20130101 |
International
Class: |
B01F 5/02 20060101
B01F005/02; C09K 8/68 20060101 C09K008/68; B01F 5/12 20060101
B01F005/12; B01F 3/12 20060101 B01F003/12; C09K 8/62 20060101
C09K008/62; B01F 5/10 20060101 B01F005/10; B01F 5/06 20060101
B01F005/06 |
Claims
1. A method of hydration of a hydratable polymer into a hydrated
fluid, the method comprising: providing a hydratable polymer and
water mixture into a tank; allowing the mixture of hydratable
polymer and water to become a hydrated fluid in the tank; pumping a
portion of the hydrated fluid, as recirculated hydrated fluid, from
the tank and recirculating at least a portion of the recirculated
hydrated fluid into a jetting system; jetting, using the jetting
system, the recirculated hydrated fluid back into the tank and
creating shear between the jetted recirculated hydrated fluid and
the hydrated fluid in the tank; and extracting at least a portion
of the hydrated fluid from an output of the tank.
2. The method of claim 1, wherein the tank comprises N tank
sections, wherein providing the mixture comprises pumping the
mixture into a first tank section of the N tank sections; and
wherein allowing the mixture further comprises allowing the mixture
of hydratable polymer and water to become a hydrated fluid while
moving from a first one of the tank section to an Nth one of the
adjacent tank sections, where N is an integer that is greater or
equal to two.
3. The method of claim 2, wherein pumping a portion of the hydrated
fluid includes extracting hydrated fluid from at least one
recirculation location that is in at least one of the N adjacent
tank sections.
4. The method of claim 1, wherein the jetting system comprises at
least one jet pipe configured to jet the recirculated hydrated
fluid into at least one of the N adjacent tank sections.
5. The method of claim 1, further comprising subjecting the mixture
to a first static mixer prior to providing the mixture into the
tank.
6. The method of claim 1, further comprising subjecting the
recirculated hydrated fluid to a second static mixer prior to
jetting.
7. The method of claim 1, wherein the jetting system comprises: a
jet manifold configured to carry the recirculated hydrated fluid;
and a plurality of jet tubes, wherein each jet tube comprises at
least one jet port positioned about the jet tube's length.
8. The method of claim 2, wherein a pumping rate of the mixture in
the step of pumping the mixture into a first tank is less than or
equal to the pumping rate of pumping a portion of the hydrated
fluid as recirculated hydrated fluid.
9. The method of claim 1, further comprising injecting hydratable
polymer into the recirculated hydrated fluid.
10. The method of claim 2, wherein the hydrated fluid moves through
at least N-1 tank sections before arriving at the Nth adjacent tank
section.
11. A hydration unit comprising: a tank configured to contain
hydrated fluid, the tank having a fluid inlet area and a fluid
output area such that the hydrated fluid moves generally from the
fluid inlet area to the fluid output area; a hydrated fluid return
pipe configured to carry hydrated fluid, as recirculated hydrated
fluid from a recirculation location; a mixing pump configured to
draw recirculated hydrated fluid from the hydrated fluid return
pipe and provide the recirculated hydrated fluid to a mixing pump
output; a jetting system configured to receive at least a portion
of the recirculated hydrated fluid pumped from the mixing pump; the
jetting system comprising: a jet tube manifold having at least one
manifold output; and a first jet tube extending from a first one of
the manifold outputs and into the tank, the first jet tube being
further configured to be at least partially submerged in hydrated
fluid when hydrated fluid is present in the tank, the first jet
tube comprising at least one jet outlet configured to jet hydrated
fluid in a direction within the tank in order impart shear on both
the recirculated hydration fluid and hydration fluid present in the
tank; and the tank fluid output area is connected to a tank
hydration fluid output configured to selectively allow hydrated
fluid to exit the tank.
12. The hydration unit of claim 11, wherein the tank is sectioned
into N tank sections such that each tank section has a tank section
fluid inlet area and a tank section fluid output area configured
such that the hydrated fluid generally moves from a first one of
the N adjacent tank sections to an Nth one of the N adjacent tank
sections via the tank section fluid inlet area and tank section
fluid output area of each one of the N tank sections
respectively.
13. The hydration unit of claim 11, further comprising: a water
input section configured to accept water from at least one water
source and provide a water flow path; a polymer phase gel input
valve section configured to accept a measured flow of polymer phase
gel and provide the flow of polymer phase gel into the water flow
path to create a mixture of polymer phase gel and water; and a
suction pump configured to receive the mixture of polymer phase gel
and water and to pump the mixture through a fluid mixture output
into the tank at the fluid inlet area as hydrated fluid.
14. The hydration unit of claim 11, wherein the tank is configured
to direct hydrated fluid to move from the fluid inlet area of the
tank to the fluid output area of the tank in a minimum amount of
time that is greater than between 0.75 to 1.5 minutes.
15. The hydration unit of claim 13, wherein the suction pump is
configurable to pump the mixture into the fluid inlet area of the
tank as hydrated fluid at a first flow rate that is equal to or
less than a selected flow rate that the hydrated fluid exits the
tank hydration fluid outlet.
16. The hydration unit of claim 15, wherein the mixing pump
provides the recirculated hydrated fluid to the jetting system at a
flow rate that is configurable to be equal to or greater than the
first flow rate.
17. The hydration unit of claim 12, wherein the tank fluid outlet
area is located in the Nth tank section.
18. The hydration unit of claim 11, wherein the hydration unit is
adapted to be mounted on a vehicle or trailer.
19. A fluid hydration device comprising: an input section adapted
to receive a fluid; a hydratable polymer input section wherein a
hydratable polymer is combined with the fluid to create a mixture;
a first pump adapted to pump the mixture into a first tank section
of a hydration tank as a hydrated fluid at a first selected flow
rate, the hydration tank being divided into a plurality of tank
sections comprising the first tank section, the plurality of tank
sections being adjacent to each other and establishing a hydrated
fluid flow path from the first tank section to a last tank section
of the plurality of tank sections; a hydrated fluid recirculation
route configured to extract hydrated fluid from one of the of tank
sections and to pump the extracted hydrated fluid through a jetting
system at a recirculation flow rate, the jetting system comprising:
a jet pipe configured to extend into one of the plurality of tank
sections, the jet pipe being configured to receive the extracted
hydrated fluid and output the fluid via a plurality of fluid jets
to cause shear to the hydrated fluid; and a hydrated fluid tank
outlet configured to allow a flow of hydrated fluid to exit the
hydration tank at a selected exit flow rate.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 14/546,358, filed on Nov. 18, 2014, entitled
GEL HYDRATION UNIT (Atty. Dkt. No. ADST-32410). application Ser.
No. 14/546,358 is a continuation of U.S. application Ser. No.
13/316,159, filed on Dec. 9, 2011, entitled GEL HYDRATION UNIT
(Atty. Dkt. No. ADST-30938), now U.S. Patent No. 8,899,823. U.S.
application Ser. Nos. 14/546,358 and 13/316,159, and U.S. Pat. No.
8,899,823 are incorporated by reference herein in their
entirety.
TECHNICAL FIELD
[0002] Embodiments of the present invention relate to methods and
apparatus that hydrate gel fracturing fluids for use in down-hole
fracturing operations. More specifically, an exemplary gel
hydration system hydrates fracturing fluids on-the-fly as it is
required for fracturing operations.
BACKGROUND
[0003] It has become common practice to pump a viscous fluid at
high pressures down into a wellbore to crack the formation and
force fracturing fluid into created cracks in order to enhance or
increase the production of oil and gas hydrocarbons from wells
bored into subterranean formations. The fracturing fluid is also
commonly used to carry sand and other types of particles, called
proppants, to hold the cracks open when the pressure is relieved.
The cracks, held open by the proppants, provide additional paths
for the oil or gas to reach the wellbore, which increases
production from the well. This process is commonly called hydraulic
fracturing or "fracking."
[0004] A hydration unit is generally used for the hydration of
fracturing fluids or hydrated fluids originating from a very
viscous fracturing fluid slurry concentrate (gel) that is mixed
with water in preparation for transfer to a blender unit prior to
being pumped under pressure down-hole. The fracturing fluid slurry
concentrate (gel) is used in a continuous hydration process in a
hydration unit so as to produce hydrated fluid as needed or
"on-the-fly" for the hydraulic fracturing process. Typically a gel
may comprise a polymer slurry wherein a hydratable polymer is
dispersed in a hydrophobic solvent (herein after referred to as an
"oil based fluid") in combination with a suspension agent and a
surfactant with or without other optional additives commonly
employed in well treatment applications. Because of the inherent
dispersion of the hydratable polymer in an oil based fluid (i.e.,
the lack of affinity for each other), such a polymer slurry or
polymer phase gel tends to not lump or hydrate prematurely prior to
dispersion, injection or being added into water. However, the rate
of polymer hydration within the gel is a critical factor
particularly in continuous mix or hydration unit applications
wherein the necessary hydration and associated viscosity rise must
take place over a relatively short time span that corresponds to a
minimum residence time of the fluids within a hydration unit during
the continuous mix procedure.
[0005] In such applications, hydration is the process by which a
hydratable polymer absorbs water. When the polymer is dispersed in
water, its ability to absorb water dictates hydration or its
hydration rate. There are several factors that determine how
readily a polymer will hydrate or develop viscosity. Such factors
include the pH of the system, the amount of mechanical shear
applied in the initial mixing phase, the concentration of salts and
the concentration of the polymer. The hydration rate can be
influenced through pH control agents, which may be blended with the
polymer in the gel or added to an aqueous medium. The hydration
rate can also be controlled by the level of applied shear, wherein
the gel-water solution's viscosity increases faster when the
hydratable polymer is subjected to high amounts of shear. Fluid
viscosity increases may also be influenced (particularly in low
shear applications) by the salts present in the solution. The
higher the salt content in the solution, the more retarded the
hydration process. The extent of viscosity retardation is dependent
on the concentration and the type of salt. Finally, the viscosity
level achieved at a particular point in time is a function of the
overall hydratable polymer concentration.
[0006] Various natural hydratable polymers are used in a polymer
phase gel. In particular, modified guar works very well and
develops viscosity in all electrolyte or salt bearing systems which
contain such salts as KCl, NaCl, and CaCl.sub.2 concentrations.
Guar gum hydrates and develops viscosity very efficiently in a pH
range of 7-8 yielding viscosities of 32 to 36 cps in 2% solution of
KCl. Hydroxypropyl guar (HPG) hydrates well in many salt systems at
80.degree. F. and also develops excellent viscosity at temperatures
around 40.degree. F. Carboxymethyl hydroxypropyl guar (CMHPG)
hydrates in most electrolyte make-up solutions, however, it's more
sensitive to such salted electrolyte solutions than unmodified guar
and HPG. CMHPG hydrates well in both cold and warm water.
[0007] In contrast to the above natural polymers, synthetic
polymers may also be dispersed and hydrated, however they may not
be as sensitive to pH effects. Consequently hydration and
dispersion of such synthetic polymers will mainly rely more on the
mixing shear applied to the aqueous medium in a hydration unit.
[0008] Generally, prior hydration units that accept a polymer phase
gel and water mixture so as to produce a hydrated fluid as part of
a continuous preparation of fracturing fluids have focused
primarily on mechanical mechanism movement or paddle based mixing
processes within a hydration unit. The paddle based mixing process
requires a large mechanical paddle or beater structure that is
rotatably mounted within a hydration unit. The paddle structure is
mechanically rotated on bearings and driven via, for example, a
chain or shaft drive, which is mechanically attached and driven by
a hydraulic, electric or combustion powered drive train and/or
transmission. Mechanical failure of any part of the drive train,
chain links and/or bearings can shut down the hydration unit, which
is expensive and time consuming to repair. Furthermore, significant
torque and horse power is required to rotate the mechanical paddles
at the speeds necessary for producing shear forces that increase
the hydration rate of the hydratable polymer and establish the
needed hydrated fluid viscosity at the hydration unit output by
such a mechanical paddle or beater based system.
[0009] What is needed is a hydration unit that can provide suitable
amounts of shear on a polymer phase gel and water mixture in order
to sufficiently increase the hydration rate of the mixture during
its residence time within the hydration unit. Furthermore, what is
needed is a hydration unit that requires fewer moving parts such as
paddles, bearings, chains and the like that are subject to wear and
breakage resulting in extended down time to repair the hydration
unit.
SUMMARY
[0010] In order to overcome the drawbacks of prior hydration units
used to create hydrated fluid or fracking fluid in the oil
exploration industry, embodiments of the invention provide a
hydration unit that utilizes high pressure recirculation jetting of
the polymer phase gel and water mixture (hydrated fluid) so as to
create high shear forces in the mixture of hydrated fluid as it
moves through and/or is recirculated in an exemplary hydration unit
so as to accelerate the hydration process.
[0011] In an embodiment of the invention a method for rapid
hydration of a polymer phase gel is provided wherein the polymer
phase gel is injected into a water stream to create a mixture. The
mixture is then pumped through a suction pump and a first static
mixer into a first tank section of a fluid tank having N adjacent
tank sections. The polymer phase gel and water mixture are allowed
to mix so that the hydratable polymer contained in the polymer
phase gel and the water become a hydrated fluid while moving from
the first tank section to the Nth tank section through at least N-1
tank sections. Hydrated fluid from the Nth tank section is also
recirculated by being pumped through a mixing pump and a second
static mixer into a jetting system. Using the jetting system, the
hydrated fluid is jetted into at least one or more of the N tank
sections via a plurality of jet openings so as to create sufficient
shear in the hydration fluid within the at least one or more tank
sections in order to increase the hydration rate of the hydration
fluid. After the hydration fluid is hydrated to a determined or
acceptable viscosity, the hydrated fluid is then extracted from the
Nth tank section and provided to another stage, such as a blender
unit, in a fracking processes.
[0012] In another embodiment of the invention a hydration unit is
provided. The hydration unit comprises a tank that is adapted to
contain hydrated fluid. The tank comprises adjacent first through N
tank sections. Each tank section comprises a fluid inlet area and a
fluid exit area such that the hydrated fluid moves from the first
to the Nth tank section in substantially a serpentine or back and
forth pattern. A hydrated fluid return pipe that is adapted to
carry hydrated fluid to be recirculated out of the Nth tank section
is positioned with an inlet in the Nth tank section. A mixing pump
draws hydrated fluid from the Nth tank section through the hydrated
fluid return pipe to provide the recirculated hydrated fluid at a
mixing pump output. A static mixer receives the recirculated
hydrated fluid from the mixing pump output and further mixes and
adds shear to the hydrated fluid as it flows therethrough. A
jetting system receives the recirculated hydrated fluid from an
output of the static mixer. The jetting system comprises a jet tube
manifold having M outputs. A first jet tube is removably attached
to a first of the M manifold outputs and extends into the first of
the N tank sections. The first jet tube comprises a first
configuration of jet outputs adapted to jet the hydrated fluid
flowing therethrough in a plurality of directions and at a
plurality of depths within the first tank section. Furthermore, an
exemplary hydration unit comprises a hydration fluid outlet that is
adapted to allow hydrated fluid to exit the tank. The hydrated
fluid outlet may include a valve to selectively adjust a flow of
the hydrated fluid exiting the tank.
[0013] Additionally, the hydration unit may further comprise a
water input section that is adapted to accept water from at least
one water source and provide the water into a water flow path. A
polymer phase gel input valve section is provided to accept a
measured flow of polymer phase gel and provide the flow of polymer
phase gel into the water flow path to create a mixture of polymer
phase gel and water. A suction pump receives a mixture of polymer
phase gel and water and pumps the mixture into the first tank
section as hydrated fluid. Between the suction pump and the first
tank section, a static mixer is positioned to statically mix the
moving mixture of hydrated fluid after leaving the suction pump but
prior to being input into a first input section of the first tank
section of the hydration unit tank.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Other objects, features, and characteristics of the
invention as well as methods of operation and functions of related
elements of structure, and the combination of parts and economics
of manufacture, will become apparent upon consideration of the
following description and appended claims with reference to the
accompanying drawings, all of which form a part of this
specification wherein like reference numerals designate
corresponding parts in the various figures, and wherein:
[0015] FIG. 1 is a first side view of an exemplary embodiment of a
hydration unit installed on a trailer;
[0016] FIG. 2 is a second side view of an exemplary embodiment of a
hydration unit installed on a trailer;
[0017] FIG. 3 is a schematic illustration of one embodiment of an
exemplary hydration process;
[0018] FIG. 4 is a schematic illustration of another embodiment of
an exemplary hydration process;
[0019] FIG. 5 is a side view drawing of an exemplary hydration
unit;
[0020] FIG. 6 is a top view drawing of a portion of an exemplary
hydration unit;
[0021] FIG. 7 is a bottom view drawing of a portion of an exemplary
hydration unit;
[0022] FIG. 8 is a three dimensional drawing of a jet tube having a
plurality of jet port configurations;
[0023] FIGS. 8A, 8B and 8C are cross-sectional views of the jet
openings as indicated in FIG. 8;
[0024] FIGS. 9A and 9B depict jet tube jet position
configurations.
DETAILED DESCRIPTION
[0025] Referring now to the drawings, wherein like reference
numbers are used herein to designate like elements throughout, the
various views and embodiments of gel hydration unit are illustrated
and described, and other possible embodiments are described. The
figures are not necessarily drawn to scale, and in some instances
the drawings have been exaggerated and/or simplified in places for
illustrative purposes only. One of ordinary skill in the art will
appreciate the many possible applications and variations based on
the following examples of possible embodiments.
[0026] The following description, which includes disclosure of
various embodiments, is merely exemplary in nature and is in no way
intended to limit the invention, its application or uses. As used
herein, a gallon is a unit of volume equivalent to about 3.8
liters. A barrel contains 42 US gallons or about 160 liters.
[0027] The rapid hydration of a water soluble polymer dispersed in
a hydrophobic solvent (the combination referred to as a "polymer
phase gel") after being injected into a stream of water, the
mixture of which being pumped into an exemplary hydration unit is
performed, at least in part, by an overall mixing intensity that
causes shear stresses within the fluid flow of the exemplary
hydration unit. The mixing intensity and agitation is performed at
least in part by the jetting of the hydration fluid into a
plurality of tank sections filled with the mixture of polymer phase
gel and water that is hydrating and referred to as hydrated fluid
which is in various stages of hydration and viscosity thicknesses.
A commercial process according to embodiments of the present
invention achieves a fast enhanced polymer hydration by utilizing a
sequence of exemplary mixing steps.
[0028] By definition, a fluid is a material continuum that is
unable to withstand a static shear stress. Unlike an elastic solid,
which responds to shear stress with a recoverable deformation, a
fluid responds to shear with an unrecoverable flow. Shear rate is
the ratio of change of velocity at which one layer of fluid passes
over an adjacent layer. As such, the greater the ratio of the
velocity change between layers of fluid, the higher the shear rate
and the greater the shear stresses or forces available to increase
the hydration rate of the hydratable fluid.
[0029] According to the embodiments of the invention a pumpable,
high concentration polymer slurry can be continuously mixed with an
appropriate water solution so as to produce a desired viscosity
rise on a real time basis, resulting in a hydrated fluid for use
in, among other things, hydraulic fracturing. Generally, an
improved method or device in accordance with embodiments of the
present invention can be employed in conjunction with any high
concentration polymer slurry comprising a hydratable polymer
dispersed in a hydrophobic solvent. Typically such a polymer slurry
or polymer phase gel is made up of at least two ingredients; namely
a hydratable polymer and a hydrophobic solvent base. Additionally,
a polymer phase gel used in embodiments of the invention may
further comprise a suspension agent and a surfactant. An exemplary
polymer phase gel is pumpable because it does not become more
viscous over a wide temperature range and has no separation and
exhibits minimal packing over periods of time, in excess of a week
or more.
[0030] The polymer phase gel or high concentration polymer slurry
is sometimes referred to as gel, fracturing fluid concentrate,
water soluble polymer phase dispersed in a hydrophobic solvent
and/or by other trade names or trade jargon. Furthermore, although
the behavior of the polymer phase gel used in exemplary embodiments
is not to be viewed as being dependent on any single explanation or
theory, and as such any proposed explanation is not to be
interpreted as unduly limiting. As such, an exemplary polymer phase
gel has the basic attributes of being a hydratable, stable,
pumpable, high concentration polymer phase gel or slurry comprising
a hydratable polymer dispersed in a hydrophobic fluid.
[0031] The dispersion of hydrophilic, hydratable polymer, which in
an aqueous medium would inherently result in a build-up of
viscosity, but when in a hydrophobic environment results in a
minimum viscosity rise. Consequently, the polymer phase gel
concentrate that may be used in embodiments of the invention
remains readily pumpable and builds viscosity only when added and
mixed with water, aqueous brine or the like. The hydrophobic
solvent or oil based fluid can be selected from the group
consisting of any of the non-volatile aliphatic and aromatic
hydrocarbons and mixtures thereof as generally known in the art.
This would include by way of example, but not limited thereto
kerosene, mineral oil, crude oil, crude oil distillates, vegetable
oil, mineral oil, silicon oils, halogenated solvents, ester
alcohols, primary/secondary/or tertiary alcohols of 6-12 carbons,
glycol ethers, glycols, animal oils and turpentine. Diesel fuel is
often employed as the hydrophobic solvent base in an exemplary
polymer phase gel.
[0032] The hydratable polymer of an exemplary polymer phase gel
that may be used in an exemplary embodiment may be essentially any
polymer of mixture of polymers as generally known in the art which
yield viscosity (i.e., produce a viscosity rise) upon hydration.
Thus, the polymers useful in embodiments of the invention include,
by way of example but not limited to, any natural or synthetic
polymers including polysaccharides and related polymeric materials
such as guar, hydroxypropyl guar (HPG), carboxymethyl hydroxypropyl
guar, carboxymethyl hydroxyethyl cellulose, other cellulosics and
cellulosic derivatives, polyacrylamides, and similar biopolymers
and mixtures thereof. The hydrated polymer that is often used in
embodiments of the invention is guar or guar derivatives.
[0033] Referring now to FIG. 1, a first side view of an exemplary
hydration unit mounted on a tractor trailer's trailer is depicted.
In this view of an exemplary gel hydration unit 100 the exterior of
the hydration tank 102 is shown. The hydration tank 102 can have
varying fluid capacities depending on the overall capacity required
of an exemplary gel hydration unit. In the embodiment shown, the
hydration tank can hold about 190 bbl or about 7980 gallons of
fluid. Below the tank 102 is a manifold having a plurality of
valves. In this embodiment, on a left side there are twelve water
input valves 104, which is where multiple hoses can connect to
provide an ample water flow into an exemplary hydration gel unit
100. The plurality of water input valves 104 are separated from the
right hand side of the manifold wherein there are 13 hydrated fluid
output valves 106. The output valves 106 and input valves 104 are
separated by a divider valve (not clearly shown in this drawing),
which can be opened or closed to alter the functionality of some or
all of the input valves 104 and output valves 106. Furthermore,
each input valve 104 and output valve 106 can be manually opened
and closed by a machine operator.
[0034] In FIG. 1, an external portion of a hydrated fluid return
pipe 108 is shown. The hydrated fluid return pipe 108 draws
hydrated fluid or partially hydrated fluid from one or more areas
within the tank 102 to provide the hydrated or partially hydrated
fluid to a mixing pump 110. The mixing pump 110 is a centrifugal
pump, which in this embodiment is adapted to pump up to about 140
bbl/min. The mixing pump 110 pumps the hydrated or partially
hydrated fluid into the return pipe 112 which is shown to return
back into the interior of the hydration tank 102. Although it
cannot be seen in this figure, inside the return pipe 112 is a
static mixer that is made of a plurality of plates adapted to spin
and swirl the fluid within the return pipe 112 adding additional
shear prior to it being returned to the interior of the hydration
tank 102.
[0035] In this view of an exemplary embodiment the polymer phase
gel pumps 114 are shown mounted on the back end of the trailer. The
polymer phase gel pumps 104 pump the polymer phase gel from a
polymer phase gel container, through a hose, a gel input valve and
gel input jet (not specifically shown in this figure). A control
panel 116 is shown mounted on an upper portion of the overall
hydration gel unit 100. The control panel 116 could be placed
substantially anywhere about the hydration gel unit. The control
panel 116 is used by a machine operator to set and monitor valve
positions, pressures, fluid flow rates, temperatures, viscosities,
pump RPM, and fluid levels of the various components that make up
the overall hydration gel unit 100. The control panel 116 can be
used by a machine operator to display all the temperatures,
pressures and rates of the chemical pumps, gel pumps, suction pump,
mixing pump, gel pumps and hydraulic pumps. The control panel can
start and stop the one or more engines that produce the
electricity, air pressure, hydraulic pressure and other means for
controlling the various components of an exemplary hydration gel
unit 100. The control panel 116 also enables the machine operator
to set the desired output viscosity of the hydration fluid that is
to be output via the output valves.
[0036] Referring now to FIG. 2, a second side view (the other side)
of an exemplary hydration gel unit is shown. Here the other side of
the hydration tank 102 can be seen with a similar set of input
valves and output valves located on the input/output manifold below
the hydration tank 102. Here the separation valve 118 (which cannot
be easily seen in FIG. 1) is depicted between the input water
valves 104 and the output hydrated fluid valves 106.
[0037] The input valves 106, as discussed above, receive a
plurality of hoses 120 wherein water flows into the input valves
and forms a single stream in the manifold thereunder. Downstream
from the input valves 104 are the gel input valves 121 wherein gel
is pumped via gel hose 124 from the polymer phase gel pumps 114.
Each gel input valve 121 can be adjusted via the control panel 116
so as to allow a determined amount of polymer phase gel to be
injected into the water stream therein. A suction pump 126, which
may be similar if not identical to the mixing pump 110, is a
centrifugal pump that sucks water from the plurality of input
valves 104 and sucks the polymer phase gel from the gel injection
area creating a mixture. The mixture's first encounter is the
suction pump's impeller, which adds shear forces to the fluid
mixture as it goes through the centrifugal suction pump 126. The
centrifugal pump 126 pumps the water/gel mixture into a mixture
input area (not specifically shown) inside the hydration tank 102.
Still referring to FIG. 2, a hydration tank output valve 128,
located proximate to the bottom of the hydration tank 102, can be
opened via the control panel 116 so as to allow hydrated fluid to
flow into the output manifold and be output via one or more output
valves 106 into a plurality hoses. The hydrated fluid that is
extracted or output from an exemplary hydration gel unit 100 may be
provided to a blender unit that further prepares the hydrated fluid
or fracking fluid for insertion into a wellhead.
[0038] Referring now to FIG. 3, in order to get a better
understanding of the process or method used in an exemplary
hydration gel unit, a process schematic is provided. As shown water
302 and polymer phase gel 304 are combined into a mixture 306 and
provided to a suction pump 307. The suction pump 307 begins the
introduction of shear to the polymer phase gel/water mixture 306 as
the suction pump's impellers pull and push the mixture 306 through
the suction pump 307. The mixture 306 exits the suction pump 307
and is input into a static mixer 308. Additional shear forces are
imparted on the mixture as it flows, swirls and spins through the
static mixer. Upon exiting the static mixer the mixture, which is
becoming hydrated fluid, is input into the hydration tank 310 in a
first tank section input area 316.
[0039] In this embodiment the hydration tank 310 is divided into N
tank sections. Each tank section is adjacent to another tank
section and separated from an adjacent tank section via a
compartment separator such as compartment separator 312. The
compartment separator is a partial wall having a width that does
not extend the full width of the hydration tank 310. FIG. 3 is
essentially a top view of an exemplary hydration tank 310.
[0040] The hydration fluid mixture 314 that is output from the
static mixer 308 is distributed into a first input area 316 of the
first tank section 318. The hydrated fluid will then flow within
the first tank section 318 from the first input area 316 toward the
first tank section exit area 320 and then into the second tank
section input area 322 of the second tank section 324. The fluid
will then flow toward the second tank section exit area 326 in a
manner shown by the flow arrows 328, 329 and 331 until it reaches
the Nth tank section 330.
[0041] FIG. 3 depicts a hydration tank 310 having four tank
sections (i.e., N=4). It is understood that an embodiment of the
invention may have anywhere from two to N distinct tank sections
that are each defined, at least in part by partial compartment
separators such as compartment separator 312 or compartment
separator 332. In an exemplary embodiment it will take a minimum of
about 45 seconds to 1.5 minutes for hydrated fluid to travel from
the first input area 316 to either the hydrated fluid output 334 or
the hydrated fluid return pipe 336. The minimum of about 45 seconds
to 1.5 minutes is necessary for the hydratable polymer phase
material in the polymer phase gel to partially hydrate enough to
impart a minimum expected viscosity increase in the hydrated fluid
that may be output at the hydrated fluid output 334.
[0042] Some of the hydrated fluid that arrives in the Nth tank
section is extracted from the Nth tank section 330 via a hydrated
fluid return pipe 336. The hydrated fluid return pipe 336
recirculates hydrated fluid to a mixing pump 338. The mixing pump
338 may be the same or similar to the suction pump 308 such that
the mixing pump 338 is a centrifugal pump which imparts shear
forces on the hydrated fluid as it is pumped from the Nth tank
section 330 and through the mixing pump 338. At the output of the
mixing pump 338 the hydrated fluid is directed toward another
static mixer 340 which like the input static mixer 308 spins and/or
turns the hydrated fluid to add additional shear forces to the
fluid in order to help accelerate the hydration of the hydratable
polymer. Upon exiting the static mixer 340, the hydrated fluid
flows into the jetting system input 342. The jetting system
comprises a jet manifold having a plurality of jet pipes (not
specifically shown in this figure) attached to M jet manifold
outputs. Each jet pipe has a plurality of jets that output the
hydrated fluid in a plurality of directions and levels inside one
or more of the N tank sections. FIG. 3 depicts each of the N tank
sections having a jet pipe 344, 346, 348 and 350 therein. For
example, the first jet pipe 344 is shown to be centrally located in
the first tank section 318 wherein a plurality of jets shoot
hydrated fluid in a plurality of directions depicted by the arrows
352. The hydrated fluid being jetted into a first tank section 318
is jetted with such force that it creates ample shearing forces on
both the hydrated fluid being jetted out each individual jet of the
first jet pipe 344 and on the preexisting hydrated fluid/polymer
phase gel water mixture in the first tank section 318. The hydrated
fluid then moves toward the first section exit area 320 and into
the second tank section input area 322 as shown by flow arrow
328.
[0043] Again, in the second tank section 324 a second jet pipe 346
jets a plurality of hydration fluid streams into the overall
hydration fluid flow moving from the second tank section input area
322 toward the second tank section exit area 326. The second jet
pipe 346, without incorporating moving mechanical parts, creates a
large shear rate by jetting the recirculated hydration fluid into
the hydration fluid that is moving through the second tank section
324. The hydrated fluid moves from the second tank section exit
area 326 into the next tank section generally as shown by flow
arrow 329. The general flow of the overall hydrated fluid from the
first tank section to the Nth tank section is a serpentine, back
and forth flow as the hydrated fluid flows from compartment section
to compartment section and is jetted, mixed and agitated by the
plurality of jets associated with each jet pipe 344, 346, 348, 350
so as to impart significant shear to the hydration fluid and
further accelerate the hydration of the polymer phase to thereby
increase the viscosity of the hydrated fluid as it moves toward the
Nth tank section 330.
[0044] In some exemplary embodiments both the suction pump 307 and
the mixing pump 338 can move a maximum of about 140 bbl/min. In
other embodiments the maximum flow rate may be faster or slower
depending on the overall hydration tank volume and the number of
tank sections. Since an exemplary hydration tank 310 can hold about
190 bbl, it follows that between the original input of the polymer
phase gel water mixture and the recirculation of the hydrated gel
via the return pipe and jetting system that the hydrated fluid can
move from the first tank section to the hydrated fluid output 334
of the Nth tank's section in a minimum of about 45 seconds to about
1.5 minutes when operating both the suction pump 307 and the mixing
pump 338 at or near maximum pumping capability. The combination of
the time it takes for the hydrated fluid to travel through the
serpentine path of the exemplary hydration tank 310 along with the
mixing, agitation and shear magnitude applied to the hydrated fluid
creates a hydrated fluid at the hydrated fluid output 334 having a
desired viscosity in the given amount of time. Furthermore, when
the suction pump 307 is not running at a maximum pumping rate, for
example, at a slower rate of 50 to 90 bbl/min, and the mixing pump
338 continues to operate at a maximum pumping rate of about 130 to
160 bbl/min, the hydrated fluid output can be limited to the same
or similar bbl/min as the suction pump bbl/min rate via hydration
tank output valve 128. This configuration enables the hydrated
fluid to recirculate multiple times via the recirculation and
jetting system route comprising the return pipe 336 the mixing pump
338 the static mixer 340 and the jetting system, which includes the
jet manifold and at least one jet pipe per each of the end tank
sections. In some embodiments there are multiple jet pipes in each
tank section.
[0045] Referring now to FIG. 4, a second embodiment of an exemplary
gel hydration unit is depicted in a schematic flow diagram. Like
the previous embodiment, water 302 and polymer phase gel 304 are
combined into a mixture 306. A suction pump 307 pumps the water gel
mixture through an input static mixer 308 and into exemplary
hydration tank 400. FIG. 4 depicts a side view flow schematic of
the exemplary hydration tank 400 wherein there are N tank sections.
Separating or defining each adjacent tank section is a separation
wall 402, 404, 406, wherein the first separation wall 402 has a
first height extending from the bottom of the hydration tank upward
and being attached to both sides of the hydration tank 400
establishing basically a single holding tank section as the first
tank section 406. The second tank section separation wall 404 may
be considered a baffle wall because the separation wall 404 extends
across the width of the hydration tank 400 and from near the top of
hydration tank 400 towards the bottom such that there is a spaced
gap between the bottom edge of the second separation wall 404 and
the bottom of the hydration tank 400 to allow hydrated fluid to
flow there through and between. The separation wall 404 separates
the second tank section 408 from the third tank section 410. The
separation wall 406 separates the third tank section 410 from the
fourth or Nth tank section 412. The separation wall 404 is similar
to the first separation wall 402, but has a height that is from
about one inch to about 1.5 feet lower than the first separation
wall 402. Each of the separation walls 402 and 406 extend a
different predetermined distance above the bottom of the hydration
tank 400. In other embodiments, the separation walls 402, 404 and
406 may be solid walls extending from the bottom to substantially
near the top of the hydration tank, but have cut-outs, or cut-away
portions at or near the top and bottom of alternating separation
walls to allow the hydration fluid to flow substantially in the
serpentine manner described herein. Additionally, in other
embodiments, one or more of the separation walls may be made
completely or in part to be or have a grid, open mesh or
screen-like wall that allows hydration fluid to flow there through
with some determined amount of restricted flow, but also add
additional shear within the hydration tank when certain ones of the
hydration fluid jet flows impact the grid or screen-like separation
wall.
[0046] The mixture 306, which is changing into hydration fluid,
enters the first section input area 420 and travels upward to the
first section output area 422. At the first section output area
422, the hydration fluid cascades as shown by the flow arrow 428
over the top of the separation wall 402 and into the second section
input area 424. The hydrated fluid then travels downward to near
the bottom of the second tank section 408 and underneath the second
separation wall 404 in a general flow as shown by flow arrow 430
where the hydrated fluid flows upward through the third tank
section 410 to the second section output area 426, where it
cascades over the separation wall 406 into the next tank section
412. This upward, downward, and then upward general serpentine
movement of the hydrated fluid continues until it reaches the
bottom of the Nth tank section 412. In exemplary embodiments,
movement of the hydrated fluid from the first input area 420 to the
bottom of the Nth tank section 412 takes a minimum of about 45
seconds to about 1.5 minutes. A return pipe 440 has an inlet
located in the Nth tank section 412 wherein hydrated fluid is
returned or recirculated toward a mixing pump 338 and then through
a recirculation static mixer 340 adding additional shear in a
manner similar to the embodiment explained in FIG. 3. The hydrated
fluid exiting the recirculation static mixer 340 is then input into
the jetting system input 444. Here, recirculated hydrated fluid is
pumped, via the mixing pump 338 into the jetting manifold 445,
which has at least one jet pipe output per tank section. The
recirculated hydrated fluid is then jetted out a plurality of jets
450, in a plurality of directions, at a plurality of depths within
the first tank section. The first jet pipe 446 schematically shows
the flow of a plurality of hydrated fluid jets that are jetted in a
plurality of directions 448 at a plurality of depths within the
first tank section 406. Note that in this embodiment the hydrated
fluid already in the tank is flowing upward through the jets 448
where strong shear forces are encountered within the first tank
section 406 from the hydration fluid jets 448 before the hydrated
fluid cascades in accordance with the flow arrow 428 over the
separation wall 402 into the second tank section 408. In the second
tank section 408, the second, third and remaining jet pipe jet the
recirculated hydrated fluid in a plurality of directions at a
plurality of depths within their respective tank sections 408, 410,
412. The plurality of jet directions and jet depths are depicted
schematically by arrows. In this embodiment, the general flow of
the hydrated fluid is in a downward direction while it is being
jetted and sheared in the second tank section 408.
[0047] In some embodiments, the first jet pipe may be positioned in
the downward general flow of the hydrated fluid in the first tank
section 406 (i.e., the mixture 314 is being poured into the top of
the first tank section 406. Furthermore, in additional embodiments
the jet system manifold may be positioned near or proximate to the
bottom of the N tank sections with the jet pipes extending upward
(instead of downward) therefrom in each tank section. In other
embodiments the jet pipes may extend from one or more jet manifolds
that extend along or proximate to one or more of the inner sides of
the hydration tank. As the hydrated fluid moves generally in the up
and down serpentine fashion from the first tank section 406 to the
Nth tank section 412, the jetting of the recirculated hydrated
fluid adds significant shear, agitation and mixing to the hydrated
fluid thereby accelerating the hydration process, which increases
the viscosity of the hydrated fluid at a more rapid rate than with
less than or without the significant shearing of the fluid caused
from, among other elements of the embodiment, the jetting,
agitation and mixing of the hydrated fluid within the N tank
sections.
[0048] Referring now to FIGS. 5, 6 and 7 a side, top and bottom
view of an exemplary gel hydration unit 500 are depicted,
respectively. The exemplary hydration unit 500 has a hydration tank
502 that is separated into N tank sections 504, 506, 508, 510 by a
plurality of tank section dividers 512, 514, 516 such that each of
the N tank sections is adjacent to at least one other tank section
within the hydration tank 502. The tank section dividers 512, 514,
516 are each attached along an edge to the bottom of the tank and
along a side edge to at least one side of the tank so as to create
a passage way for fluid to flow between each tank section 504, 506,
508, 510 and a side wall of the hydration tank 502. External to the
hydration tank 502 is a water input section 518. The water input
section has a water input manifold portion 520 with the plurality
of (in this embodiment 12) water input valves 522. Each water input
valve 522 may be attached via a hose to a water or fluid supply. In
some embodiments, each water input valve 522 may connect to a four
inch diameter hose. If each four inch hose is capable of carrying a
maximum flow of about five to ten barrels of fluid per minute then
by connecting 12 hoses, one to each water input valve 522, the
amount of water that can be input into the water input manifold 520
may range from about 60 to about 120 bbl/min. Some embodiments
comprise larger input valves, for example one or more eight inch
input valves may be connected to the input manifold 520, which can
each carry a maximum fluid flow of from about 36 to 50 bbl/min.
Thus, in some embodiments the input manifold 520 may have a water
flow input 524 from ranging from zero to about 120 bbl/min.
Embodiments may have fewer or additional input valves associated
with a single water input manifold 520 that may affect the fluid
throughput. Furthermore, a second input manifold may be used via
the water input cross pipe 526, which extends and connects to a
location on the other side of the hydration tank 502 that provides
a second water input manifold (see FIGS. 1 and 2). A water input
cross pipe valve (also not specifically shown) may be located
between the water input manifold 520 and the second water input
manifold at the other end of the cross pipe 526 so as to enable use
or non-use of the second water input manifold. Furthermore, if the
hydration tank output valve 528 (shown in FIG. 5) is closed and the
manifold separation valve 530 is opened, the plurality of output
valves 532 on the hydration fluid output manifold section 534 can
be used as input valves in association with the water input section
518 so as to increase an amount of water flow in bbl/min into an
exemplary gel hydration unit.
[0049] The water flows in the direction of the water flow arrow 524
due to the suction pump 536 pulling the water or fluid flow through
the one or more water input valves 522 of the water input section
518. The suction pump 536 may be a centrifugal pump or other
reasonably comparable pump capable of pumping from about 120 to
about 200 bbl/min max. The centrifugal suction pump 536 may be
powered by a hydraulic system, electricity or a combustion engine
and transmission associated with the exemplary gel hydration unit
500. As the water or fluid is sucked toward the suction pump 536,
polymer phase gel is injected through a polymer phase gel input
valve 538 at a rate determined by the machine operator and/or the
control panel. The polymer phase input valve 538 may include one or
more input valves that allow the polymer phase gel to be injected
into a central location of the water flow 524 prior to entering the
suction pump 536.
[0050] The water and polymer phase gel mixture is input on the
suction side of the suction pump 536. The impeller of the suction
pump 536 imparts initial shear to the water/gel mixture when it
flows through the centrifugal pump so as to initiate and expedite
the hydration of the hydratable polymer within the polymer phase
gel. The initial mixture flows from the output of the suction pump
536 past a flow meter 540, which measures the total flow of the
water/polymer phase gel initial mixture to be input into the
hydration tank 502. The flow meter 540 provides mixture flow rate
542 information to the control panel computer (not specifically
shown) so as to help enable overall control of the gel hydration
process. The tank inlet valve 544 is opened while the bypass valve
545 is closed so that the input mixture flow 542 is pumped toward
and through the input static mixer 546. The input static mixer 546
spins and mixes the initial input mixture within the pipe prior to
its distribution into the hydration tank as hydrated fluid
(although at this point the hydrated fluid is only partially
hydrated) 550. The hydrated fluid 550 is output into the first tank
section 504 via the fluid mixture outlet 552.
[0051] The hydrated fluid 550 continues to hydrate as it flows from
the first input area 548 through the first tank section 504 and/or
the first tank section output area 551, and then between the tank
section divider 512 and the hydration tank 502 sidewall 511 as
depicted by the hydrated fluid flow arrow 554. The hydrated fluid
then enters the second tank's section input area 556 and moves
toward the second tank section output area 558, which is on the
other side of the second tank section. The hydrated fluid flows in
this back and forth serpentine manner through the N tank sections
until reaching the Nth tank section as shown by the hydrated fluid
flow arrow 559, 560.
[0052] The hydrated fluid 550 may then flow into the return inlet
562 of the return pipe 564. The return pipe input 562 is positioned
within the Nth tank section 510 proximate to the bottom of the
hydration tank 502. The return pipe in this exemplary embodiment is
a twelve inch diameter pipe and the hydrated fluid 550 is drawn
through the return pipe 564 toward the mixing pump 566. The mixing
pump 566 may be substantially similar to the suction pump 536 or
may be of an alternate pump design. The mixing pump 566 is used to
recirculate the hydrated fluid back into the plurality of N tank
sections 504, 506, 508, 510 via the jetting system in order to
cause additional significant shear on the hydrated fluid. In some
embodiments prior to the recirculated hydrated fluid being pumped
into the jetting system input 570, the recirculating hydrated fluid
may go through a recirculation static mixer 572 positioned in the
fluid line between the output of the mixing pump 566 and the
jetting system input 570. Both the recirculation static mixer 572
and the mixing pump 566 provide additional shear to the hydrated
fluid flow so as to help increase the hydration rate of a
hydratable polymer within the hydrated fluid 550. An exemplary
jetting system comprises a jet manifold 574 having M manifold
outputs where M jet pipes attach. The M jet pipes 576, 578, 580,
582 each extend into the hydrated fluid 550 that is moving in the
back and forth serpentine manner through the N tank sections 504,
506, 508, 510. In some embodiments the jetting system manifold 574
can be from 8-14 inches in diameter.
[0053] Each jet tube may be removably attached to the jet manifold
574 via, for example, a Victaulic.RTM., Teekay.RTM., Gruvlok.RTM.,
or Swagelok.RTM. pipe coupling system or clamp, a threaded
connection, a weld or other reasonably similar or derivative
locking bracket or pipe connection means 581 known to one of
ordinary skill in the art. The jet pipes in some exemplary
embodiments are six inch diameter pipes and allow hydrated fluid
from the manifold 574 into an input side of the jet pipe and out a
plurality of jet openings 584 organized about the sides of the
tubular length of the jet pipe so as to allow the hydrated fluid to
be jetted out of the jets as shown by the jet flow arrows 586 in
FIGS. 5 and 6. In the exemplary embodiment shown, each exemplary
jet pipe has six levels of jets and six jets 586 or jet openings
584 spaced circumferentially about each jet tube. It has been found
through experimentation that the jet openings 584 on the first jet
pipe 576 should be from 25% to 100% larger than the jet openings on
the Mth jet pipe 582 (in this embodiment the 4.sup.th jet pipe). It
was found that the jet pipe openings should be smaller in first jet
pipe 576 than in the Mth jet pipe 582 so that the hydrated fluid
being pumped by the mixing pump 566 will be distributing either
more evenly between each of the N tank sections or so that more of
the hydrated fluid is delivered to the first tank section 502 then,
for example, the Nth tank section 510. The distal end of each jet
pipe may be closed, or in some embodiments incorporate an
additional jet outlet.
[0054] The jet openings 584 may be in the form of slits, circles,
ovals and other geometric shapes. Referring for a moment to FIG. 8,
an exemplary jet pipe 800 is shown having three different exemplary
types of jet openings. The first jet opening is a straight jet slit
802 wherein fluid being jetted out of the slit will be jetted
straight out and substantially radially from the outer surface of
the jet pipe 800 (see cross-sectional view A). A second exemplary
jet shaped configuration is a cross or plus sign shaped jet opening
804 wherein each extension of the cross or plus shape is cut
through the jet pipe at a cut angle 806 (shown also in cutaway view
B) that is from 30.degree. to about 60.degree.
(120.degree.-150.degree. such that each extension of the exemplary
plus or cross shaped jet will direct hydrated fluid so that the jet
will spin or spiral out of the plus or cross shaped jet opening 804
that may also be referred to as a quad angled jet opening. A jet
pipe with the exemplary quad angle jet 804 is shown as the first
jet pipe 576 positioned in the first tank section 504, shown in
FIGS. 5 and 6. The spiraling jet stream created by the exemplary
quad angle jet 804 is shown as the spiral fluid motion arrows 587
as seen in the first tank section 504 in the top view of FIG. 6.
The various jet opening configurations provide varying amounts of
additional shear to the turbulent hydration fluid 550 flowing
within the plurality of hydration tank sections.
[0055] Referring back to FIG. 8, a third exemplary jet opening
configuration is depicted as an angled jet slit 808 wherein the
slit is made through the outer wall of the jet pipe 800 at an angle
that may be 30 to 60.degree. with respect to either a radial line
extending from a central axis of the jet pipe 800 or with respect
to a tangent of the outer surface of the jet pipe 800. The angled
jet slit 800 will jet hydrated fluid in an angular direction about
the circumference of the exemplary six inch diameter jet pipe 800.
An exemplary angle jet slit 808 can be cut to angle the jet fluid
flow to the left or the right so that the jets of, for example the
third jet pipe 580 can jet the fluids so that it moves in a
clockwise or counterclockwise rotation about the third jet tube 580
as shown in the third tank section 508 in FIGS. 5 and 6.
[0056] The jetting of the recirculated hydrated fluid out of the
jet pipe jets produces a significant amount of shear between the
jetted recirculated hydrated fluid and the hydrated fluid already
flowing in each of the N tank sections. It has been found that with
a straight jet such as exemplary straight jet 802 shown in FIG. 8
that the jet streams indicated by arrows 586 penetrate and shear
all the way through the hydrated fluid already in, for example the
second tank section 504, and impacts the inner hydration tank walls
as well as the tank section dividers 512 and 514, which creates
magnitudes of shear, and does not require moving parts such as
paddles, link chains, bearings gears that are subject to wear and
breakage, inside the hydration tank 502. Through experimentation it
appears that the additional shear created within embodiments of the
exemplary gel hydration units accelerate the hydration of the
hydratable polymers within the hydrated fluid up to 15 percent
faster than various existing mechanical, paddle based hydration
units.
[0057] During normal operation, the mixing pump 566 can be operated
continuously at or near its maximum pumping rate, which in some
exemplary embodiments is around 120 to 200 bbl/min. If an exemplary
hydration tank 502 holds about 190 to 200 bbl of fluid, then the
mixing pump can move or recirculate the entire fluid contents of
the hydration tank 502 about once every 0.75 to 1.5 minutes.
Furthermore, if the suction pump 536 is pumping the water-polymer
phase gel mixture into the first tank section 504 at a slower rate
of from about 60 bbl/min to about 100 bbl/min wherein the exemplary
hydration tank 502 can hold from about 190 to about 200 bbl of
hydrated fluid, it will take the newly inserted hydrated fluid that
enters the first tank section 504 about 1 to 1.5 minutes to travel
through the back and forth serpentine path while encountering
mixing, agitation, and extreme shear from the multiple jets
positioned in each of the N tank sections to get to the Nth tank
section and be extracted on a continuous basis through the
hydration tank outlet 600 or outlets 600, 600'. Much of the
hydration fluid being extracted will have circulated through the
recirculation system and jets multiple times prior to extraction
thereby creating a more hydrated hydration fluid on-the-fly (i.e.,
continuous) that requires less polymer slurry or polymer phase gel
to create.
[0058] After exiting the hydration tank 502 via the hydration tank
outlet 600, 600', the hydrated fluid passes a hydration tank outlet
valve 528 (528') and is delivered into the hydrated fluid output
section 602. The hydrated fluid output section has a plurality of
output valves 532 that can be connected to a plurality of hoses
(not specifically shown) extending from the output valves 532 to,
for example, a blender unit. The output valves 532 may each have a
manual output valve control 604 so that it can be manually opened
or closed by a machine operator. Some embodiments may have a larger
diameter output valve 606 that may be an eight inch valve as
compared to the exemplary four inch output valves 532. In other
embodiments the valves may be further controlled by the control
panel.
[0059] It has been found in some embodiments that improved
hydration of the hydrated fluid occurs when the mixing pump 566 is
operated at or near its maximum pumping capacity so that the
recirculation of the hydrated fluid and the shear created by the
jetting and agitation of the fluid created by the plurality of jets
in the jet pipes is maximized. It is further found that although
embodiments of the invention work well and produce a uniform and
needed hydrated fluid at the hydrated fluid output section when the
suction pump 536 is operating at or near its maximum pumping
potential, viscous hydration fluid blend that requires up to about
15% less polymer phase gel than pre-existing mechanical paddle
based hydration units can be provided when the suction pump 536 is
operating at a pumping rate that is at least 25% less than the
maximum pumping rate of the mixing pump 566, which recirculates the
hydrated fluid.
[0060] Referring now to FIGS. 9A and 9B it is shown that the jet
pipes 900 and 902 may have the plurality of jet openings 904 or 906
respectively configured differently thereon. For example, in FIG.
9A there are multiple levels of jet openings 904, wherein at each
level the jet openings are spaced circumferentially about the
exemplary jet tube 900. Alternatively, in FIG. 9B the jet openings
906 are configured to spiral circumferentially along the length of
the exemplary jet tube 902 thereby creating a helix or double helix
jetting configuration. Various other jet position configurations on
a jet tube may also be devised by one of ordinary skill in the
art.
[0061] Many variations and embodiments of the above-described
invention and method are possible. Although only certain
embodiments of the invention method have been illustrated in the
accompanying drawings and described in the foregoing detailed
description, it will be understood that the invention is not
limited to the embodiments disclosed, but is capable of additional
rearrangements, modifications and substitutions without departing
from the invention as set forth and defined by the following
claims. Accordingly, it should be understood that the scope of the
present invention encompasses all such arrangements and is solely
limited by the claims as follows.
* * * * *