U.S. patent application number 12/255478 was filed with the patent office on 2009-10-01 for system and method for polymer distribution to well sites.
Invention is credited to Chong Chan, Brad Falez, Art Laurin, Murray MacKinnon, Chris Markwart, Cary G. Reid, Farid Remtulla, Brian Starr, Jorgen Van Beurden.
Application Number | 20090242201 12/255478 |
Document ID | / |
Family ID | 41115374 |
Filed Date | 2009-10-01 |
United States Patent
Application |
20090242201 |
Kind Code |
A1 |
Van Beurden; Jorgen ; et
al. |
October 1, 2009 |
SYSTEM AND METHOD FOR POLYMER DISTRIBUTION TO WELL SITES
Abstract
The invention relates to a polymer transport and distribution
system comprising a vessel, pipeline or network of pipes containing
polymer mother solution, and one or more pumps for transporting
polymer mother solution from a first location to one or more
injection well sites at a second remote location, each injection
well comprising a polymer mother solution input feed line, a water
input feed line, and a second pump for controlling mother solution
flow rate and pressure upstream from the water input feed line, for
producing polymer daughter solution from polymer mother solution
and water, and injecting the resulting polymer daughter solution
into an oil or gas field well. Also provided are methods of
distributing polymer to one or more injection well sites in an oil
or gas field.
Inventors: |
Van Beurden; Jorgen;
(Calgary, CA) ; Falez; Brad; (Calgary, CA)
; Markwart; Chris; (Calgary, CA) ; Reid; Cary
G.; (Calgary, CA) ; Chan; Chong; (Calgary,
CA) ; Laurin; Art; (Calgary, CA) ; Starr;
Brian; (Calgary, CA) ; MacKinnon; Murray;
(Calgary, CA) ; Remtulla; Farid; (Calgary,
CA) |
Correspondence
Address: |
CLARK & ELBING LLP
101 FEDERAL STREET
BOSTON
MA
02110
US
|
Family ID: |
41115374 |
Appl. No.: |
12/255478 |
Filed: |
October 21, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12074721 |
Mar 5, 2008 |
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12255478 |
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11821621 |
Jun 25, 2007 |
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12074721 |
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Current U.S.
Class: |
166/275 ;
166/305.1; 166/90.1 |
Current CPC
Class: |
E21B 21/062 20130101;
E21B 43/20 20130101 |
Class at
Publication: |
166/275 ;
166/90.1; 166/305.1 |
International
Class: |
E21B 43/16 20060101
E21B043/16; E21B 43/25 20060101 E21B043/25; E21B 43/20 20060101
E21B043/20 |
Claims
1. A polymer transport and distribution system comprising, a
vessel, pipeline or network of pipes containing polymer mother
solution, and; one or more pumps for transporting polymer mother
solution from a first location to one or more injection well sites
at a second remote location, each injection well comprising a
polymer mother solution input feed line, a water input feed line,
and a second pump for controlling mother solution flow rate and
pressure upstream of the water input feed line, and for producing
polymer daughter solution from polymer mother solution and water,
and injecting the resulting polymer daughter solution into an oil
or gas field well.
2. The polymer transport and distribution system of claim 1,
further comprising at least one mixer for mixing polymer mother
solution with water.
3. The polymer transport and distribution system of claim 1,
wherein the polymer comprises polyacrylamide, hydrolysed
polyacrylamide, xanthan gum, guar gum, diutan gum, welan gum or a
combination thereof.
4. The polymer transport and distribution system of claim 3,
wherein the polymer comprises a viscosity in the range of about 1
to about 25000 cP.
5. The polymer transport and distribution system of claim 1,
wherein either the polymer mother solution, the polymer daughter
solution or both comprise less than about 50000 ppm total dissolved
solids.
6. The polymer transport and distribution system of claim 1,
wherein the polymer mother solution, polymer daughter solution or
both comprise a surfactant, biocide, alkaline component,
antifoaming agent, or a combination thereof.
7. The polymer transport and distribution system of claim 1,
wherein the polymer daughter solution comprises polymer mother
solution diluted with water.
8. The polymer transport and distribution system of claim 8,
wherein said water is derived from a saline well, a freshwater
well, a water filtration skid or a combination thereof.
9. The polymer transport and distribution system of claim 1 further
comprising one or more of: a) a dry polymer holding vessel; b) a
dry polymer transfer system; c) a water inlet source for hydrating
dry polymer; d) an input source for adding one or more additional
components to the dry polymer, water or polymer mother solution, e)
a mixer for preparing polymer mother solution, and; g) a polymer
mother solution holding vessel.
10. The system of claim 9, comprising a dry polymer polymer
transfer system, wherein said system comprises a calibrated auger
or a helix conveyor.
11. The system of claim 10, wherein the system comprises a
mixer.
12. A polymer transport and distribution system comprising, a dry
polymer transfer system, a water inlet source, and a first mixer
for preparing a polymer mother solution from said dry polymer and
water, one or more pumps for transporting polymer mother solution
through a pipeline or network of pipes to one or more remote
injection pod sites, each injection pod site comprising, one or
more injection wells, each injection well comprising a polymer
mother solution input feed line and a water input feed line to
produce polymer daughter solution, and a pump for controlling
mother solution flow rate and pressure upstream of the water input
feed line, for injecting the resulting polymer daughter solution
into a well.
13. A method of distributing polymer to one or more injection well
sites in an oil or gas field comprising, a) providing a polymer
mother solution; b) pumping the polymer mother solution through a
pipeline or network of pipes from a first location to one or more
remote locations comprising at least one injection pod or well
site; c) mixing the polymer mother solution with water and
optionally one or more additional components to form a polymer
daughter solution and; d) injecting the polymer daughter solution
into a well.
14. A method of distributing polymer to one or more injection well
sites in an oil or gas field comprising, a) storing or producing a
polymer mother solution in a polymer processing station; b) pumping
the polymer mother solution through a pipeline or network of pipes
from the polymer processing station to one or more remote injection
pods or injection well sites; c) mixing the polymer mother solution
with water and optionally one or more additional components at the
injection pod or injection well contained therein to form a primary
polymer daughter solution and; d) injecting the primary polymer
daughter solution into the injection well; e) extracting oil or gas
from a producer well in fluid communication with the injection
well, and; f) optionally, mixing polymer mother solution with water
and if desired, one or more additional components at the injection
pod or injection well site contained therein to form a secondary
polymer daughter solution, wherein the secondary polymer daughter
solution is more dilute in polymer concentration and less viscous
than the primary daughter solution, g) injecting the secondary
daughter polymer solution into the injection well; h) extracting
oil from the producer well in fluid communication with the
injection well, and; i) optionally repeating steps f)-h) using
successively more dilute and less viscous daughter solutions.
Description
FIELD OF INVENTION
[0001] The present invention relates to oil and gas recovery. More
specifically, the present invention relates to polymer use in oil
and gas recovery.
BACKGROUND OF THE INVENTION
[0002] Polymer compounds are used in the oil industry to prevent
fingering in subterranean oil formations. In most cases, polymer
solutions are prepared at each well site and the resulting
formulation is injected into a well. As most oil fields comprise
several injector-producer wells, there is often a need to inject
polymer into several wells within the field. Typically, at each
injection well, dry polymer powder is mixed with an appropriate
quantity of water and the resulting solution is injected into the
well. This approach requires dry polymer to be transported to the
various well sites. Further, mixing systems, polymer holding tanks
and the like must be stationed at each well site where polymer is
injected. This requires transportation systems such as roads and
other types of costly infrastructure to be implemented to ensure
that the proper components and products are present at the
appropriate locations and at the appropriate times. Further, this
type of approach must be monitored closely to ensure a continuous
supply of dry polymer for injection and also to ensure the
mechanical components required for injection at each point are
working properly.
[0003] There is a need in the art for novel polymer transportation
and distribution systems in oil and gas fields. Further, there is a
need for systems and methods of preparing polymer at a central
location and transporting the same, potentially over large
distances to several well sites where the polymer may be diluted if
necessary to a desired viscosity and pumped down-well.
SUMMARY OF THE INVENTION
[0004] The present invention relates to oil and gas recovery. More
specifically, the present invention relates to polymer use in oil
and gas recovery.
[0005] According to the present invention, there is provided a
polymer transport and distribution system comprising, [0006] a
vessel, pipeline or network of pipes containing polymer mother
solution, and; [0007] one or more pumps for transporting polymer
mother solution from a first location to one or more injection well
sites at a second remote location, each injection well comprising a
polymer mother solution input feed line, a water input feed line, a
second pump for controlling mother solution flow rate and pressure,
the second pump upstream of the water input feed line, for
producing polymer daughter solution from polymer mother solution
and water, and injecting the resulting polymer daughter solution
into an oil or gas field well.
[0008] Also according to the present invention, there is provided a
polymer transport and distribution system comprising, [0009] a
vessel, pipeline or network of pipes containing polymer mother
solution, and; [0010] one or more pumps for transporting polymer
mother solution from a first location to one or more injection well
sites at a second remote location, each injection well comprising a
polymer mother solution input feed line, a high pressure dilution
water input feed line, and a second pump for controlling mother
solution flow rate and pressure, upstream of the high pressure
dilution water input feed line for producing polymer daughter
solution from polymer mother solution and water, and injecting the
resulting polymer daughter solution into an oil or gas field
well.
[0011] Also provided is a polymer transport and distribution system
as defined above, further comprising at least one mixer for mixing
polymer mother solution with water.
[0012] The present invention also contemplates a polymer transport
and distribution system as defined above, wherein the polymer
comprises polyacrylamide, hydrolysed polyacrylamide, xanthan gum,
guar gum, diutan gum, welan gum or a combination thereof.
[0013] Also provided is a polymer transport and distribution system
as defined above, wherein the polymer comprises a viscosity in the
range of about 1 to about 25000 cP.
[0014] The present invention further contemplates a polymer
transport and distribution system as defined above, wherein either
the polymer mother solution, the polymer daughter solution or both
comprise less than about 50000 ppm total dissolved solids. In an
embodiment, which is not meant to be limiting, the polymer mother
solution, polymer daughter solution or both comprise less than
about 25000 ppm, more preferably less than about 18000 ppm total
dissolved solids. In a further embodiment, which is not meant to be
limiting, the polymer mother solution, polymer daughter solution or
both comprise less than 5000 ppm total dissolved solids.
[0015] Also provided by the present invention is a polymer
transport and distribution system as defined above, wherein the
polymer mother solution, polymer daughter solution or both comprise
a surfactant, biocide, alkaline component, antifoaming agent, or a
combination thereof.
[0016] The present invention also contemplates a polymer transport
and distribution system as defined above, wherein the polymer
daughter solution comprises polymer mother solution diluted with
water.
[0017] Also provided by the present invention is a polymer
transport and distribution system as defined above, wherein the
water is derived from a saline well, a freshwater well, a water
filtration skid or a combination thereof.
[0018] The present invention also contemplates a polymer transport
and distribution system further comprising one or more of: [0019]
a) a dry polymer holding vessel; [0020] b) a dry polymer transfer
system; [0021] c) a water inlet source for hydrating dry polymer;
[0022] d) an input source for adding one or more additional
components to the dry polymer, water or polymer mother solution,
[0023] e) a mixer for preparing polymer mother solution, and;
[0024] g) a polymer mother solution holding vessel.
[0025] Also provided by the present invention is a polymer
transport and distribution system as defined above that comprises a
dry polymer polymer transfer system, wherein the system comprises a
calibrated auger or a helix conveyor. Also, the system may further
comprise a mixer.
[0026] The present invention also contemplates a polymer transport
and distribution system comprising, [0027] a dry polymer transfer
system, a water inlet source, and a first mixer for preparing a
polymer mother solution from said dry polymer and water, [0028] one
or more pumps for transporting polymer mother solution through a
pipeline or network of pipes to one or more remote injection pod
sites, each injection pod site comprising, [0029] one or more
injection wells, each injection well comprising a polymer mother
solution input feed line, one or more pumps for controlling mother
solution flow rate and pressure upstream of a water input feed
line, preferably a high pressure dilution water input feed line, to
produce polymer daughter solution for injection into a well.
[0030] The present invention also provides a method of distributing
polymer to one or more injection well sites in an oil or gas field
comprising, [0031] a) providing a polymer mother solution; [0032]
b) pumping the polymer mother solution through a pipeline or
network of pipes from a first location to one or more remote
locations comprising at least one injection pod or well site;
[0033] c) mixing the polymer mother solution with water and
optionally one or more additional components to form a polymer
daughter solution and; [0034] d) injecting the polymer daughter
solution into a well.
[0035] The present invention also provides a method of distributing
polymer to one or more injection well sites in an oil or gas field
comprising, [0036] a) storing or producing a polymer mother
solution in a polymer processing station; [0037] b) pumping the
polymer mother solution through a pipeline or network of pipes from
the polymer processing station to one or more remote injection pods
or injection well sites; [0038] c) mixing the polymer mother
solution with water and optionally one or more additional
components at the injection pod or injection well contained therein
to form a primary polymer daughter solution and; [0039] d)
injecting the primary polymer daughter solution into the injection
well; [0040] e) extracting oil or gas from a producer well in fluid
communication with the injection well, and; [0041] f) optionally,
mixing polymer mother solution with water and if desired, one or
more additional components at the injection pod or injection well
site contained therein to form a secondary polymer daughter
solution, wherein the secondary polymer daughter solution is more
dilute in polymer concentration and less viscous than the primary
daughter solution, [0042] g) injecting the secondary daughter
polymer solution into the injection well; [0043] h) extracting oil
from the producer well in fluid communication with the injection
well, and; [0044] i) optionally repeating steps f)-h) using
successively more dilute and less viscous daughter solutions.
[0045] This summary of the invention does not necessarily describe
all features of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0046] These and other features of the invention will become more
apparent from the following description in which reference is made
to the appended drawings wherein:
[0047] FIG. 1 shows a representative embodiment of a polymer
transport and distribution system according to the present
invention.
DETAILED DESCRIPTION
[0048] The following description is of a preferred embodiment.
[0049] The present invention will be further illustrated in the
following examples.
[0050] According to an embodiment of the present invention, there
is provided a polymer transport and distribution system comprising,
[0051] a vessel, pipeline or network of pipes containing polymer
mother solution; [0052] one or more pumps for transporting polymer
mother solution from a first location to one or more injection well
sites at a second remote location, each injection well comprising a
polymer mother solution input feed line, a water input feed line,
and a second pump for controlling mother solution flow rate and
pressure, preferably at or upstream of the water input feed line,
for producing polymer daughter solution from polymer mother
solution and water, and injecting the resulting polymer daughter
solution into an oil or gas field well. In a preferred embodiment,
the water input feed line is a high pressure dilution input feed
line.
[0053] In a preferred embodiment, which is not meant to be limiting
in any manner, there is provided a polymer transport and
distribution system comprising, [0054] a vessel containing a
polymer mother solution; [0055] one or more pumps for transporting
polymer mother solution from the vessel through a pipeline or
network of pipes to one or more injection pod sites, each injection
pod site comprising, [0056] a second pump for controlling mother
solution flow rate and pressure upstream of a high pressure
dilution water input feed line used to produce polymer daughter
solution from polymer mother solution and water, the water
optionally derived from a vessel, pipeline or network of pipes
carrying water, and injecting the resulting polymer daughter
solution into an oil or gas field well.
[0057] It is to be understood that the polymer transport and
distribution system may further comprise a mixer that mixes the
polymer mother solution with water to produce polymer daughter
solution. Inclusion of a mixer is optional as the combination of
polymer mother solution with water to make polymer daughter
solution and the subsequent injecting of the polymer daughter
solution into an oil and gas field well is usually sufficient to
ensure thorough mixing. However, there are instances whereby it may
be desirable to include a mixer, for example, but not limited to,
when the viscosity of the polymer mother solution is high compared
to that of water or in instances when the polymer mother solution
is diluted by either a very small or very large amount. A person of
skill in the art would be able to determine if a mixer should be
included in the polymer transport and distribution system having
regard to the information provided herein.
[0058] By the term "polymer mother solution" it is meant an aqueous
solution comprising a polymer, water and optionally one or more
additional components. The polymer may comprise any polymer known
in the art, for example, but not limited to polyacrylamide
including, but not limited to hydrolyzed polyacrylamide, xanthan
gum, guar gum, diutan gum, welan gum or a combination thereof. In
an embodiment of the present invention, which is not meant to be
limiting in any manner, the polymer mother solution comprises a
polyacrylamide polymer. In an alternate embodiment, the polymer
mother solution comprises xanthan gum. In still a further
embodiment, which is not meant to be limiting, the polymer mother
solution comprises guar gum. However, it is to be understood that
other types of polymers, biopolymers, viscosifying agents or any
combination thereof may be employed in the present invention.
Accordingly, the list of polymers provided above is not meant to be
limiting in any manner.
[0059] The polymer mother solution preferably has a viscosity in
the range of about 1 to about 25000 cP, more preferably about 5 to
15000 cP and still more preferably about 10 to about 10000 cP. For
example, the polymer mother solution may comprise a viscosity of
about 1, 5, 10, 50, 100, 500, 1000, 2000, 5000, 10000, 15000,
20000, 25000 cP or any amount therein between. Further, the
viscosity of the polymer mother solution may be defined by a range
of any two of the values provided above or any amounts therein
between. However, a polymer mother solution comprising
characteristics outside one or more of these ranges is also
contemplated.
[0060] The viscosity of polymer mother solution may be measured
according to known methods in the art, and any such method may be
employed to determine the viscosity of the polymer solutions as
defined herein. For example, but not to be considered limiting in
any manner, viscosity may be measured in accordance with the
American Petroleum Institute (API) Recommended Practice 63 (RP63),
First Edition, Jun. 1, 1990, which is hereby incorporated by
reference.
[0061] In embodiments wherein the polymer mother solution comprises
polyacrylamide polymer, it is preferred that the solution does not
comprise water with high levels of total dissolved solids,
particularly cationic or divalent species as these components can
inhibit hydrolysis of polymer and/or breakdown the viscosity of
such polymer solutions. In embodiments wherein polyacrylamide
polymer is employed in the polymer transport and distribution
system, preferably the total dissolved solids is less than about
5000 ppm, more preferably less than 2000 ppm.
[0062] By the term "total dissolved solids" it is meant the sum of
anions and cations from water analysis. Cations may be determined
by Inductively Coupled Plasma (ICP) using American Public Health
Association (APHA) 3120 method. Chloride may be determined by
titration (APHA 4500-C1:B), sulfate by APHA 3120 and alkalinity by
titration according to APHA 2320:B. Alternatively, other methods to
measure total dissolved solids as would be known to a person of
skill in the art may be employed.
[0063] As xanthan gum polymers exhibit increased resistance to
viscosity breakdown in the presence of salts, the use of such
polymers is preferred in instances wherein the polymer is mixed
with water that comprises a high content of total dissolved solids,
salts, iron, iron-containing species, or a combination thereof. In
a preferred embodiment, which is not meant to be limiting in any
manner, xanthan gum polymers are employed in polymer compositions
wherein the content of total dissolved solids (excluding polymer)
is greater than about 2000 ppm.
[0064] As described previously, it is also contemplated that the
polymer mother solution may comprise one or more additional
components, for example, but not limited to a surfactant, biocide,
alkaline component such as, but not limited to caustic soda,
antifoaming agent, or a combination thereof. In the event that a
surfactant or other component is employed in the polymer mother
solution, it preferably comprises an amount between about 20 parts
per million (ppm) and about 5000 ppm, preferably about 500 ppm and
about 5000 ppm, for example, but not limited to 20, 50, 100, 200,
500, 1000, 2000, 2500, 3000, 4000, 5000 or any amount therein
between. Further, the surfactant may be defined by a range of any
two of the values listed above or any amount therein between.
Without wishing to be bound by theory or limiting in any manner, a
surfactant may lower the interfacial tension of oil deposits and
facilitate extraction from subterranean formations.
[0065] By the term "polymer daughter solution" it is meant an
aqueous solution comprising the polymer mother solution, water and
optionally one or more additional components. Typically, the
polymer daughter solution comprises a polymer concentration that is
about the same or less than the polymer mother solution. As such,
the polymer daughter solution usually comprises a lower viscosity
than the polymer mother solution.
[0066] It is also to be understood that the polymer daughter
solution may comprise one or more additional components not found
in the polymer mother solution. Similarly, the polymer daughter
solution may comprise one or more additional components in a
different concentration as compared to the polymer mother solution.
By way of example, but not to be considered limiting in any manner,
the polymer mother solution may be prepared using a potable water
source having low salinity. Prior to being injected into a well,
the polymer mother solution may be diluted with water from a saline
well having high salinity. Accordingly, it is apparent that the
polymer daughter solution may comprise higher levels of dissolved
salts, and potentially other components as compared to the polymer
mother solution. In still a further embodiment, which is not meant
to be considered limiting in any manner, the polymer daughter
solution may comprise an added surfactant not present in the
polymer mother solution. Other potential differences between the
polymer mother solution and the polymer daughter solution will be
evident to a person of skill in the art having regard to the
disclosure as provided herein.
[0067] In an embodiment which is not meant to be limiting in any
manner, the polymer daughter solution is polymer mother solution
diluted with water. In a specific embodiment, but not wishing to be
considered limiting in any manner, the polymer daughter solution
comprises polyacrylamide solution of between about 500 ppm and
about 2000 ppm, more preferably about 1000 to about 1500 ppm.
However, a polymer daughter solution outside this range is also
contemplated.
[0068] In the embodiments described herein, it is preferred that
polymer mother solution is sufficiently hydrolysed prior to being
diluted to form polymer daughter solution and before injection into
a well. For example, but not wishing to be limiting, the polymer
mother solution may remain in a vessel, holding tank, pipeline or
network of pipes for at least a specified duration in order for the
polymer to hydrolyse to a desired viscosity. Further, it is
contemplated that the extent of hydrolysis and/or the viscosity of
the solution may be measured and/or monitored at one or more points
within the polymer transport system including for example, but not
limited to the vessel, holding tank, pipeline, network of pipes, or
injection pod polymer mother solution feed line by any method known
in the art. Without wishing to be limiting or bound by theory in
any manner, it is possible that some polymers may require time to
fully hydrate, unravel and expand to create a viscous solution.
[0069] The polymer mother solution may be provided as a premade
solution or alternatively, the polymer mother solution may be
prepared on site, for example, but not limited to, by mixing
together dry polymer, water and optionally one or more additional
components. Accordingly, the polymer transport and distribution
system may comprise a dry polymer holding vessel or container, a
dry polymer transfer system, a water inlet source, an input source
for optionally adding one or more additional components to the dry
polymer, water or polymer mother solution, a mixer for preparing
the polymer mother solution, a polymer mother solution transport
system, for example, but not limited to one or more pumps, a vessel
or container for holding polymer mother solution, one or more
pipelines or network of pipes or any combination thereof. Several
or all of these components may be contained in a polymer processing
station (polymer pod) which may be or may not be located remotely
from the injection pod sites and wells.
[0070] The water inlet source providing water for mixing with
polymer may be provided from a well, for example, but not limited
to a freshwater or saline well, water pipeline, water filtration
skid or the like. It is also contemplated that the water inlet
source may be connected to a water pipeline or network of water
pipes that extends over the oil/gas field being tapped. In an
embodiment, the water is substantially pure meaning that it
comprises a low amount, for example between 1500 to about 2500 ppm,
or lower of total dissolved solids as described herein,
particularly salts as high levels of salts and are known to inhibit
hydrolysis and/or promote breakdown of hydrolysed polymers such as
polyacrylamides. However, water from a saline well also may be
employed, and may be preferred in instances wherein the polymer is
resistant to viscosity breakdown in the presence of dissolved
salts.
[0071] Dry polymer may be fed into a mixer by a dry polymer
transfer system which may comprise without limitation, a calibrated
auger or the like. In a preferred embodiment, the dry polymer
transfer system comprises a Hapman helix conveyor. Alternatively,
the dry polymer may be transferred by an air transfer system or
both an air transfer system and a conveyor. Any such system as
would be known in the art may be employed in the polymer transport
and distribution system. Further, one or more optional components
may be added likewise or they may be added using other methods
and/or apparatuses known in the art.
[0072] The mixing of dry polymer, water and optionally any
additional components may be performed in any vessel, holding tank
or pipeline by a suitable mixer or mixing device. In a preferred
embodiment, the mixer or mixing device is a Model 1700 Comitrol
Processor made by Urschel Labs. Such a device has been shown to
decrease the time necessary to prepare viscous polymer mother
solution. While such devices are preferred, other mixing devices
can be employed in the present invention. As will be evident to a
person of skill in the art, it is preferred that polymer powder is
thoroughly mixed with water and attains the desired viscosity prior
to being diluted to form polymer daughter solution or injected into
a well. In this manner, polymer mother solution may be prepared and
retained in a vessel or holding tank until the polymer mother
solution exhibits a desired viscosity. Alternatively, polymer
mother solution may be prepared and transported in a pipeline or
network of pipes to a second remote location. In such an
embodiment, it is preferred that the polymer mother solution attain
the desired viscosity while being pumped through the pipeline or
network of pipes before being diluted to form polymer daughter
solution or injected into a well.
[0073] The embodiment described above contemplates that that the
vessel containing the polymer mother solution or the polymer
processing station that prepares the polymer mother solution can be
located remotely from the injection pod or well sites, for example,
but not limited to about 1, 2, 5, 6, 10 or more km therefrom. Thus,
polymer mother solution may be prepared and/or stored in a separate
area, building, or facility from that of the injection pods wherein
the daughter polymer solution is injected into a well. Polymer
mother solution can be pumped from this remote site through a
pipeline or network of pipes to the injection pod sites wherein the
polymer mother solution is diluted with water and optionally
formulated with other components to obtain a daughter polymer
solution having a desired viscosity and/or one or more desired
chemical characteristics for injection into a well. Further, but
without wishing to be limiting in any manner, the water used for
mixing with polymer mother solution may be provided via a vessel,
pipeline or network of pipes that parallels or intersects that
providing the polymer mother solution at one or more points. In an
embodiment of the present invention, the polymer transport and
distribution system comprises a plurality of injection pod sites,
for example, two, three, four, five or more injection pod sites. In
a preferred embodiment, the polymer transport and distribution
system comprises five or less sites. Similarly, in an embodiment of
the present invention, the polymer transport and distribution
system comprises a plurality of injection wells within each
injection pod site, for example two, three, four or more injection
wells. In a preferred embodiment the polymer distribution and
transport system comprises four injection wells within each
injection pod site.
[0074] Referring now to FIG. 1, there is shown a representative
non-limiting embodiment of the present invention. Polymer
processing station (polymer pod (10)) receives water from a
freshwater source (20) to produce polymer mother solution which is
pumped through polymer mother solution pipeline network (30) to a
plurality of injection pods or injection well sites (40). Each
injection well site (40) comprises a polymer mother solution feed
line (50), a water input feed line (60) providing high pressure
dilution water from water pipeline network (35) and at least a
second pump for controlling mother solution flow rate and pressure
upstream of the water input feed line used for producing and
injecting polymer daughter solution into an oil or gas field well
(70). Also shown are producer wells (80) for extracting oil and gas
from subterranean formations in an oil or gas field (100).
[0075] In an alternate embodiment of the present invention which is
not meant to be limiting in any manner, the polymer transport and
distribution system comprises, [0076] a dry polymer transfer
system, a water inlet source, and a first mixer for preparing a
polymer mother solution from dry polymer and water, the resulting
polymer mother solution contained in a vessel; [0077] one or more
pumps for transporting polymer mother solution through a pipeline
or network of pipes to one or more remote injection pod sites, each
injection pod site comprising, [0078] one or more injection wells,
each injection well comprising a polymer mother solution input feed
line, a high pressure water input feed line, a second mixer to
produce polymer daughter solution and a pump for controlling mother
solution flow rate and pressure upstream of a high pressure
dilution water input feed line, for injecting the resulting polymer
daughter solution into a well.
[0079] The present invention also provides a method of distributing
polymer to one or more injection well sites in an oil or gas field
comprising, [0080] a) providing a polymer mother solution; [0081]
b) pumping the polymer mother solution through a pipeline or
network of pipes from a first location to one or more remote
locations comprising at least one injection pod or well site;
[0082] c) mixing the polymer mother solution with water and
optionally one or more additional components to form a polymer
daughter solution and; [0083] d) injecting the polymer daughter
solution into a well.
[0084] In a further embodiment of the present invention there is
provided a method of distributing polymer to one or more injection
well sites in an oil or gas field comprising, [0085] a) storing or
producing a polymer mother solution in a polymer processing
station; [0086] b) pumping the polymer mother solution through a
pipeline or network of pipes from the polymer processing station to
one or more remote injection pod or well sites; [0087] c) mixing
the polymer mother solution with water and optionally one or more
additional components to form a polymer daughter solution and;
[0088] d) injecting the polymer daughter solution into a well.
[0089] In an alternate embodiment of the present invention, there
is provided a method of distributing polymer to one or more
injection well sites in an oil or gas field comprising, [0090] a)
storing or producing a polymer mother solution in a polymer
processing station; [0091] b) pumping the polymer mother solution
through a pipeline or network of pipes from the polymer processing
station to one or more remote injection pods or injection well
sites; [0092] c) mixing the polymer mother solution with water and
optionally one or more additional components at the injection pod
or injection well contained therein to form a primary polymer
daughter solution and; [0093] d) injecting the primary polymer
daughter solution into the injection well; [0094] e) extracting oil
from a producer well in fluid communication with the injection
well, and; [0095] f) optionally, mixing polymer mother solution
with water and if desired, one or more additional components at the
injection pod or injection well site contained therein to form a
secondary polymer daughter solution, wherein the secondary polymer
daughter solution is more dilute in polymer concentration and less
viscous than the primary daughter solution, [0096] g) injecting the
secondary daughter polymer solution into the injection well; [0097]
h) extracting oil from the producer well in fluid communication
with the injection well, and; [0098] i) optionally repeating steps
f)-h) using successively more dilute and less viscous daughter
solutions.
EXAMPLES
[0099] In a preferred embodiment of the present invention, polymer
is brought onto a skid in 750 kg bags via an overhead crane. The
bags of dry polymer are hoisted over top and unloaded into a
hopper. From the hopper, the polymer is transferred, for example
via a Hapman helix conveyor/auger to a storage silo. From storage
silo, polymer powder is augured into a mixer, for example, but not
limited to an Urschel mixer or the like. Water is filtered through
a standard bag filter and then fed into the mixer at the same time
in controlled proportions to created the required polymer mother
solution. Typically, but not always, the polymer mother solution
comprises from about 5000 to 15000 ppm depending on particular well
injection requirements. The polymer mother solution falls out of
the bottom of the urschel mixer and is then transferred to a tank
via a lobe pump where it undergoes hydrolysis prior to being
diluted to form polymer daughter solution.
[0100] Once the polymer mother solution has sufficiently
hydrolysed, it is pumped through a pipeline or pipeline network to
the injection pod or injection well sites. This is accomplished by
a progressive cavity pump which draws the polymer off the bottom of
the tank and pressurizes it up to the pressure required to
transport the polymer to distant/remote injection pod or well
sites. In this example, but not to be considered limiting in any
manner, the pipeline feeds up to 5 injection pods which are up to
about 1.6 km away from the polymer processing station. Each
injection pod comprises a separate pump for each well wherein
polymer is injected. The pod sites are laid out with 4 injection
wells per pod. There is one injection skid per pod which has four
pumps in it to feed the wells. Polymer mother solution is metered
as it goes out the building, and then it is blended with water to
create polymer daughter solution having the required polymer
concentration before being injected down the wells. Typical polymer
concentrations of polymer daughter solution injected down each well
are about 1000 to about 1500 ppm thus requiring roughly a 9:1 blend
of water to polymer mother solution.
[0101] All citations are hereby incorporated by reference.
[0102] The present invention has been described with regard to one
or more embodiments. However, it will be apparent to persons
skilled in the art that a number of variations and modifications
can be made without departing from the scope of the invention as
defined in the claims.
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