U.S. patent application number 12/841543 was filed with the patent office on 2012-01-26 for real-time field friction reduction meter and method of use.
This patent application is currently assigned to HALLIBURTON ENERGY SERVICES, INC.. Invention is credited to Jason E. Bryant, Johanna Anna Haggstrom.
Application Number | 20120018148 12/841543 |
Document ID | / |
Family ID | 44629657 |
Filed Date | 2012-01-26 |
United States Patent
Application |
20120018148 |
Kind Code |
A1 |
Bryant; Jason E. ; et
al. |
January 26, 2012 |
Real-time field friction reduction meter and method of use
Abstract
A method of servicing a subterranean formation comprising
communicating a servicing fluid comprising a hydratable friction
reducer and a base fluid to the subterranean formation via a route
of fluid communication, determining an actual percent by which the
friction reducer reduces a pipe friction pressure, comparing the
actual percent by which the friction reducer reduces the pipe
friction pressure to an ideal percent by which the friction reducer
should reduce pipe friction pressure to determine an effectiveness
of the friction reducer, and determining if the effectiveness of
the friction reducer is within an acceptable range. A method of
servicing a subterranean formation comprising communicating a
servicing fluid comprising a hydratable friction reducer and a base
fluid to the subterranean formation via a route of fluid
communication, measuring a wellhead pressure, determining a pipe
friction pressure independent from the wellhead pressure,
calculating a formation response pressure, and monitoring the
formation response pressure.
Inventors: |
Bryant; Jason E.; (Duncan,
OK) ; Haggstrom; Johanna Anna; (Duncan, OK) |
Assignee: |
HALLIBURTON ENERGY SERVICES,
INC.
Houston
TX
|
Family ID: |
44629657 |
Appl. No.: |
12/841543 |
Filed: |
July 22, 2010 |
Current U.S.
Class: |
166/250.01 |
Current CPC
Class: |
C09K 8/62 20130101; E21B
43/114 20130101; E21B 47/10 20130101; C09K 2208/28 20130101; E21B
43/26 20130101; C09K 8/74 20130101 |
Class at
Publication: |
166/250.01 |
International
Class: |
E21B 47/00 20060101
E21B047/00 |
Claims
1. A method of servicing a subterranean formation comprising:
communicating a servicing fluid comprising a hydratable friction
reducer and a base fluid to the subterranean formation via a route
of fluid communication; determining an actual percent by which the
friction reducer reduces a pipe friction pressure; comparing the
actual percent by which the friction reducer reduces the pipe
friction pressure to an ideal percent by which the friction reducer
should reduce pipe friction pressure to determine an effectiveness
of the friction reducer; and determining if the effectiveness of
the friction reducer is within an acceptable range.
2. The method of claim 1, further comprising determining the ideal
percent by which the friction reducer should reduce pipe friction
pressure.
3. The method of claim 1, wherein the ideal percent by which the
friction reducer should reduce pipe friction comprises a previously
determined value.
4. The method of claim 1, wherein determining the actual percent by
which the friction reducer reduces the pipe friction comprises:
diverting at least a portion of the servicing fluid from the route
of fluid communication through a friction reducer meter; measuring
a pressure at a first point within the friction reducer meter and a
pressure at a second point within the friction reducer meter; and
calculating the difference between the pressure at the first point
and the pressure at the second point.
5. The method of claim 4, wherein the flow of the portion of the
servicing fluid diverted through the friction reducer meter
comprises a turbulent fluid flow.
6. The method of claim 1, wherein the determination of the
effectiveness of the friction reducer is determined at the instant
of measuring the pressure at the first point within the friction
reducer meter and the pressure at the second point within the
friction reducer.
7. The method of claim 1, further comprising adjusting the
composition of the servicing fluid, the route of fluid
communication, or both in response to the effectiveness of the
friction reducer where the effectiveness of the friction reducer is
not within the desirable range.
8. The method of claim 7, wherein adjusting the composition of the
servicing fluid comprises altering the amount of friction reducer,
altering the type of friction reducer, adding second friction
reducer, adding a component to the base fluid, subtracting a
component from the base fluid, altering the composition of the base
fluid, or combinations thereof.
9. The method of claim 7, wherein adjusting the route of fluid
communication comprises altering the amount of time for hydration
of the friction reducer, altering the amount of time prior to
communicating the servicing fluid to the subterranean formation,
altering the amount of time the servicing fluid is mixed, altering
the pressure at which the servicing fluid is communicated to the
subterranean formation, altering the volume of servicing fluid
communicated to the subterranean formation, or combinations
thereof.
10. The method of claim 1, wherein adjusting the servicing fluid
increases the hydration of the friction reducer.
11. The method of claim 1, wherein adjusting the servicing fluid
increases the effectiveness of the friction reducer.
12. The method of claim 1, wherein the route of fluid communication
comprises one or more storage vessels, one or more supply lines, a
blending pump, a low-pressure-side conduit, one or more
pressurizing pumps, a manifold, a high-pressure-side conduit, a
wellhead, the pipe string, one or more pathways between the pipe
string and the subterranean formation, or combinations thereof.
13. The method of claim 1, wherein the base fluid comprises an
aqueous base fluid.
14. The method of claim 1, wherein the aqueous base fluid comprises
water produced from the subterranean formation.
15. The method of claim 1, wherein the servicing fluid comprises a
fracturing fluid.
16. The method of claim 15, wherein the fracturing fluid comprises
a proppant.
17. The method of claim 1, wherein the servicing fluid comprises a
perforating fluid, a hydrajetting fluid, or combinations
thereof.
18. The method of claim 1, wherein the friction reducer comprises a
polyacrylamide, a copolymer of polyacrylamide and acrylic acid, a
copolymer of polyacrylamide and 2-acrylamido-2-methylpropane
sulfonic acid (AMPS), or combinations thereof.
19. The method of claim 1, wherein the servicing fluid further
comprises a proppant, an acid, an abrasive, a scale inhibitor, a
rheology modifying agent, a resin, a viscosifying agent, a
suspending agent, a dispersing agent, a salt, an accelerant, a
surfactant, a retardant, a defoamer, a settling prevention agent, a
weighting material, a vitrified shale, a formation conditioning
agent, a pH-adjusting agent, or combinations thereof.
20. A method of servicing a subterranean formation comprising:
communicating a servicing fluid comprising a hydratable friction
reducer and a base fluid to the subterranean formation via a route
of fluid communication; measuring a wellhead pressure; determining
a pipe friction pressure independent from the wellhead pressure;
calculating a formation response pressure; and monitoring the
formation response pressure.
21. The method of claim 20, wherein determining the pipe friction
pressure comprises: diverting at least a portion of the servicing
fluid from the route of fluid communication through a friction
reducer meter; measuring a pressure at a first point within the
friction reducer meter and a pressure at a second point within the
friction reducer meter; and calculating the difference between the
pressure at the first point and the pressure at the second
point.
22. The method of claim 21, wherein the flow of the portion of the
servicing fluid diverted through the friction reducer meter
comprises a turbulent fluid flow.
23. The method of claim 20, further comprising adjusting the
composition of the servicing fluid, adjusting the route of fluid
communication, or both in response to the formation response
pressure.
24. The method of claim 23, wherein adjusting the composition of
the servicing fluid comprises altering the amount of friction
reducer, altering the type of friction reducer, adding second
friction reducer, adding a component to the base fluid, subtracting
a component from the base fluid, altering the composition of the
base fluid, altering the type of servicing fluid communicated, or
combinations thereof.
25. The method of claim 23, wherein adjusting the route of fluid
communication comprises altering the amount of time prior for
hydration of the friction reducer, altering the amount of time
prior to communicating the servicing fluid to the subterranean
formation, altering the amount of time the servicing fluid is
mixed, altering the pressure at which the servicing fluid is
communicated to the subterranean formation, altering the volume of
servicing fluid communicated to the subterranean formation, or
combinations thereof.
26. The method of claim 20, wherein adjusting the communication of
the servicing fluid comprises altering the pressure at which fluid
is communicated, altering the rate at which fluid is communicated,
or combinations thereof.
27. The method of claim 20, wherein the servicing fluid comprises a
fracturing fluid, a perforating fluid, a hydrajetting fluid, or
combinations thereof.
28. The method of claim 20, wherein the servicing fluid further
comprises a proppant, an acid, an abrasive, a scale inhibitor, a
rheology modifying agent, a resin, a viscosifying agent, a
suspending agent, a dispersing agent, a salt, an accelerant, a
surfactant, a retardant, a defoamer, a settling prevention agent, a
weighting material, a vitrified shale, a formation conditioning
agent, a pH-adjusting agent, or combinations thereof.
29. The method of claim 20, wherein the route of fluid
communication comprises one or more storage vessels, one or more
supply lines, a blending pump, a low-pressure-side conduit, one or
more pressurizing pumps, a manifold, a high-pressure-side conduit,
a wellhead, the pipe string, one or more pathways between the pipe
string and the subterranean formation, or combinations thereof.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
REFERENCE TO A MICROFICHE APPENDIX
[0003] Not applicable.
BACKGROUND
[0004] Hydrocarbon-producing wells often are serviced by a variety
of operations involving introducing a servicing fluid into a
portion of a subterranean formation penetrated by a wellbore.
Examples of such servicing operations include a fracturing
operation, a hydrajetting operation, an acidizing operation, or the
like. In providing such a servicing fluid to the subterranean
formation, it is often desirable to employ a friction reducer to
lessen the friction between the servicing fluid and the conduit
through which the servicing fluid is communicated to the
formation.
[0005] Servicing fluids and the components comprising those
servicing fluids are diverse. As such, a given friction reducer may
not be compatible with a given servicing fluid and, therefore, may
be ineffective to reduce the friction between the servicing fluid
and the conduit through which the servicing fluid is communicated
to the subterranean formation. Further, because the constituents
and the relative amounts of those constituents of a servicing fluid
may be changed or varied over the course of a servicing operation,
the effectiveness of a given friction reducer may vary over the
course of a servicing operation. As the effectiveness of the
friction reducer changes, the friction between the servicing fluid
and the conduit through which the servicing fluid is flowing will
also likely change. As such, because the friction between the
flowing servicing fluid and the conduit through which the servicing
fluid flows changes, the pressure due to friction between the
flowing servicing fluid and the innermost surface of the conduit,
referred to herein as "pipe friction pressure," may vary.
[0006] During a servicing operation, various factors contribute to
the total pressure experienced within the conduit through which the
servicing fluid is communicated; the pipe friction pressure is one
such component. Therefore, changes in the pipe friction pressure
may yield a change in the total pressure. Conventionally, there has
been no means by which to assess whether a change in the total
pressure is due to a change in the effectiveness of the friction
reducer employed (resulting in a change in the pipe friction
pressure) or to some other component of the total pressure. In many
situations, it is desirable to know whether changes in the total
pressure are the result of a change in the effectiveness of the
friction reducer or some other factor. As such, there exists a need
for methods, systems, and apparatuses for determining the
effectiveness of a friction reducer in subterranean formation
servicing operations.
SUMMARY
[0007] Disclosed herein is a method of servicing a subterranean
formation comprising communicating a servicing fluid comprising a
hydratable friction reducer and a base fluid to the subterranean
formation via a route of fluid communication, determining an actual
percent by which the friction reducer reduces a pipe friction
pressure, comparing the actual percent by which the friction
reducer reduces the pipe friction pressure to an ideal percent by
which the friction reducer should reduce pipe friction pressure to
determine an effectiveness of the friction reducer, and determining
if the effectiveness of the friction reducer is within an
acceptable range.
[0008] Further disclosed herein is a method of servicing a
subterranean formation comprising communicating a servicing fluid
comprising a hydratable friction reducer and a base fluid to the
subterranean formation via a route of fluid communication,
measuring a wellhead pressure, determining a pipe friction pressure
independent from the wellhead pressure, calculating a formation
response pressure, and monitoring the formation response
pressure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a partial cutaway view of the operating
environment of the invention depicting a wellbore penetrating a
subterranean formation.
[0010] FIG. 2 is a partial cutaway view of an embodiment of
friction reducer effectiveness meter.
[0011] FIG. 3 is a schematic overview of a method of servicing a
subterranean formation.
[0012] FIG. 4 is a graph depicting the percent friction reduction
over time for various servicing fluids.
DETAILED DESCRIPTION
[0013] Unless otherwise specified, use of the terms "connect,"
"engage," "couple," "attach," or any other like term describing an
interaction between elements is not meant to limit the interaction
to direct interaction between the elements and may also include
indirect interaction between the elements described.
[0014] Unless otherwise specified, use of the terms "up," "upper,"
"upward," "uphole," "upstream," or other like terms shall be
construed as generally from the formation toward the surface or
toward the surface of a body of water; likewise, use of "down,"
"lower," "downward," "downhole," "downstream," or other like terms
shall be construed as generally into the formation away from the
surface or away from the surface of a body of water, regardless of
the wellbore orientation. Use of any one or more of the foregoing
terms shall not be construed as denoting positions along a
perfectly vertical axis.
[0015] Unless otherwise specified, use of the term "subterranean
formation" shall be construed as encompassing both areas below
exposed earth and areas below earth covered by water such as ocean
or fresh water.
[0016] Referring to FIG. 1, an embodiment of an operating
environment for a Friction Reducer Effectiveness (FRE) meter and a
method of using the same is illustrated. It is noted that although
some of the figures may exemplify horizontal or vertical wellbores,
the principles of the devices, systems, and methods disclosed may
be similarly applicable to horizontal wellbore configurations,
conventional vertical wellbore configurations, and combinations
thereof. Therefore, the horizontal or vertical nature of any figure
is not to be construed as limiting the wellbore to any particular
configuration.
[0017] As depicted in FIG. 1, the operating environment generally
comprises a wellbore 114 that penetrates a subterranean formation
102 for the purpose of recovering hydrocarbons, storing
hydrocarbons, disposing of carbon dioxide, or the like. The
wellbore 114 may be drilled into the subterranean formation 102
using any suitable drilling technique. In an embodiment, a drilling
or servicing rig comprises a derrick with a rig floor through which
a pipe string 150 (e.g., a drill string, segmented tubing, coiled
tubing, etc.) may be positioned within or partially within the
wellbore 114. A wellbore servicing apparatus 140 configured for one
or more wellbore servicing operations may be integrated within the
pipe string 150. Additional downhole tools may be included with or
integrated within the wellbore servicing apparatus and/or the pipe
string 150 for example, one or more isolation devices, for example,
packers such as swellable packers or mechanical packers.
[0018] The drilling or servicing rig may be conventional and may
comprise a motor driven winch and other associated equipment for
lowering the pipe string 150 into the wellbore 114. Alternatively,
a mobile workover rig, a wellbore servicing unit (e.g., coiled
tubing units), or the like may be used to lower the pipe string 150
into the wellbore 114.
[0019] The wellbore 114 may extend substantially vertically away
from the earth's surface over a vertical wellbore portion, or may
deviate at any angle from the earth's surface 104 over a deviated
or horizontal wellbore portion. In alternative operating
environments, portions or substantially all of the wellbore 114 may
be vertical, deviated, horizontal, and/or curved. In some
instances, a portion of the pipe string 150 may be secured into
position within the wellbore 114 in a conventional manner using
cement 116; alternatively, the pipe string 150 may be may be
partially cemented in wellbore 114; alternatively, the pipe string
150 may be uncemented in the wellbore 114. In an embodiment, the
pipe string 150 may comprise two or more concentrically positioned
strings of pipe (e.g., a first pipe string may be positioned within
a second pipe string). It is noted that although some of the
figures may exemplify a given operating environment, the principles
of the devices, systems, and methods disclosed may be similarly
applicable in other operational environments, such as offshore
and/or subsea wellbore applications.
[0020] The devices, methods, and systems disclosed herein generally
relate to an FRE meter. In an embodiment, the FRE meter may be
employed to independently determine one or more components of the
total pressure during a subterranean formation servicing operation.
In an embodiment, independently determining one or more components
of the servicing fluid may allow adjustment of the servicing
operation to achieve a desired result.
[0021] Referring again to FIG. 1, an embodiment of a route of fluid
communication to the subterranean formation 102, illustrated by
flow arrows 10, is shown in the context of a wellbore servicing
equipment spread or layout (e.g., a fracturing spread) assembled at
a well site. In the embodiment of FIG. 1, the route of fluid
communication 10 may generally comprise one or more storage vessels
230, one or more supply lines 220, a blending pump 210, a
low-pressure-side conduit 200, one or more pressurizing pumps 190,
a high-pressure manifold 180, a high-pressure-side conduit 170, a
wellhead 160, the pipe string 150, and, optionally, one or more
pathways between the pipe string 150 and the formation 102.
Although FIG. 1 illustrates a general route of fluid communication
to the subterranean formation 102, the FRE meter disclosed herein
may be applicable to other suitable routes of fluid communication.
For example, a route of fluid communication, like the route of
fluid communication illustrated in FIG. 1, may further comprise
various other fluid conduits, such as, one or more conduits leading
to the manifold.
[0022] In an embodiment, the one or more storage vessels 230 may
comprise any suitable storage device, for example a tank,
reservoir, hopper, container, or the like. The storage vessels 230
may be portable or movable, alternatively, permanent or
semi-permanent. The storage vessels 230 may be configured to store
a given material or substance as will be necessary for a given
servicing operation. In a non-limiting example, the storage vessels
may be individually configured for the storage of a liquid, a
solid, a semi-solid, a suspension, a powder, a slurry, a gas, or
combinations thereof. In an embodiment, one or more components of
the servicing fluid may be stored in the one or more storage
vessels. For example, a first storage vessel 230 may store a first
servicing fluid component (e.g., a base fluid, as will be discussed
herein below), a second storage vessel 230 may store a second
servicing fluid component (e.g., a friction reducer, as will be
discussed herein below), and a third, fourth, fifth, etcetera,
storage vessel 230 may store one or more additional servicing fluid
components.
[0023] In an embodiment, the one or more storage vessels 230 may be
connected to one or more supply lines. The supply lines 220 may
comprise any suitable conduit, nonlimiting examples of which
include a pipe, a line, a tubing member, or the like. The supply
lines may comprise flowbore extending therethrough. In an
embodiment, the one or more supply lines 220 may comprise a route
of fluid communication between the storage vessels 230 and the
blending pump 210. In an alternative embodiment, one or more of the
storage vessels 230 may be directly connected to the blending pump
210.
[0024] In an embodiment, the one or more supply lines 220 may be
connected to the blending pump 210. The blending pump 210 may
comprise any suitable configuration. The blending pump 210 may be
configured to blend servicing fluid components introduced therein
and to discharge the resulting composition therefrom. The blending
pump 210 may comprise a route of fluid communication between the
one or more supply lines 220 and the low-pressure-side conduit
200.
[0025] In an embodiment, the blending pump 210 may be connected to
a low-pressure-side conduit 200. The low-pressure-side conduit 210
may comprise any suitable conduit, nonlimiting examples of which
include a pipe, a line, a tubing member, or the like. The
low-pressure-side conduit 200 may comprise a flowbore extending
therethrough. The low-pressure-side conduit may comprise a route of
fluid communication between the blending pump 210 and the one or
more pressurizing pumps 190.
[0026] In an embodiment, the low-pressure-side conduit 200 may be
connected with the one or more pressurizing pumps 190. The
pressurizing pumps 190 may be configured to increase the pressure
of a fluid moving therethrough. Although FIG. 1 illustrates three
independent pressurizing pumps, any suitable number of pumps may be
employed. The pressurizing pumps may comprise any suitable type or
configuration of pump. Nonlimiting examples of a suitable pump
include a centrifugal pump, a gear pump, a screw pump, a roller
pump, a scroll pump, a piston pump, a progressive cavity pump, or
combinations thereof. The one or more pressurizing pumps 190 may
comprise a route of fluid communication between the
low-pressure-side conduit 200 and the manifold 180.
[0027] In an embodiment, the one or more pressurizing pumps 190 may
be connected with the manifold 180. The manifold 180 may suitably
comprise one or more pipes, lines, valves, connections, the like,
or combinations thereof. In an embodiment, the manifold 180 may be
configured to merge two or more fluid streams (e.g., from the one
or more pressurizing pumps 190) into a single fluid stream. The
manifold 180 may comprise a flowbore comprising a route of fluid
communication between the pressurizing pumps 190 and the
high-pressure-side conduit 170.
[0028] In an embodiment, the manifold 180 may be connected with the
high-pressure-side conduit 170. The high-pressure-side conduit 170
may comprise any suitable conduit, nonlimiting examples of which
include a pipe, a line, a tubing member, or the like. The
high-pressure-side conduit 170 may comprise an axial flowbore
extending therethrough. The high-pressure-side conduit 170 may
comprise a route of fluid communication between the manifold 180
and the wellhead 160.
[0029] In an embodiment, the high-pressure-side conduit 170 may be
connected with the wellhead 160. The wellhead may suitably comprise
one or more pipes, lines, valves, connections, the like, or
combinations thereof. The wellhead 160 may comprise one or more
flowbores for the communication of a fluid therethrough. The
wellhead 160 may comprise a route of fluid communication between
the high-pressure-side conduit 170 and the pipe string 150.
[0030] In an embodiment, the wellhead 160 may be connected to the
pipe string 150. The pipe string 150 may comprise a flowbore for
the communication of fluid therethrough. In various embodiments,
the pipe string 150 may comprise a casing string, a liner, a
production tubing, coiled tubing, a drilling string, the like, or
combinations thereof. The pipe string 150 may extend from the
earth's surface 104 downward within the wellbore 114 to a
predetermined or desirable depth.
[0031] In an embodiment where the route of fluid communication 10
comprises a wellbore servicing apparatus 140, the wellbore
servicing apparatus 140 or some part thereof may be incorporated or
integrated within the pipe string 150. The wellbore servicing
apparatus 140 may be configured to perform a given servicing
operation, for example, fracturing the formation 102, expanding or
extending a fluid path through or into the subterranean formation
102, producing hydrocarbons from the formation 102, or other
servicing operation. In an embodiment, the wellbore servicing
apparatus 140 may comprise one or more ports, apertures, nozzles,
jets, windows, or combinations thereof for the communication of
fluid from the flowbore of the pipe string 150 to the subterranean
formation 102. In an embodiment, the wellbore servicing apparatus
comprises a housing comprising a plurality of housing ports, a
sleeve being movable with respect to the housing, the sleeve
comprising a plurality of sleeve ports, the plurality of housing
ports being selectively alignable with the plurality of sleeve
ports to provide a fluid flow path from the wellbore servicing
apparatus to the wellbore, the subterranean formation, or
combinations thereof. Such a wellbore servicing apparatus is
described in greater detail in U.S. application Ser. No.
12/274,193, which is incorporated in its entirety herein by
reference.
[0032] Persons of ordinary skill in the art with the aid of this
disclosure will appreciate that the components of route of fluid
communication 10 described herein may be connected and/or coupled
via any suitable connection. Nonlimiting examples a suitable
connections may include flanges, collars, welds, or combinations
thereof. One of more of the components of route of fluid
communication 10 may include various configurations of pipe tees,
elbows, the like, or combinations thereof.
[0033] In an embodiment the FRE meter generally comprises a route
of fluid communication of a servicing fluid, a side-stream from the
route of fluid communication, a flow meter disposed in the
side-stream, two or more pressure gauges, optionally, a flow
regulator, and, optionally, a side-stream valve. The side-stream
may be configured such that a portion of the servicing fluid flows
may be diverted from the route of fluid communication through the
side-stream.
[0034] Referring to FIG. 2, an embodiment of an FRE meter 300 is
illustrated. In the embodiment of FIG. 2, the FRE meter comprises a
side-stream 310, a first pressure gauge 320a, a second pressure
gauge 320b, a flow-rate meter 330, one or more optional side-stream
valves 350, and an optional flow regulator 340.
[0035] In an embodiment, the FRE meter 300 may be connected to one
or more suitable components of a route of fluid communication such
as route of fluid communication 10. In the embodiment of FIG. 2,
the FRE meter 300 is connected to and in fluid communication with
the low-pressure-side conduit 200. In alternative embodiments, one
of skill in the art viewing the instant disclosure will recognize
that the FRE meter 300 might be connected to the storage vessels
230, to the supply lines 220, the blending pump 210, the
low-pressure-side conduit 200, the one or more pressurizing pumps
190, the manifold 180, the high-pressure-side conduit 170, the
wellhead 160, the pipe sting 150, or combinations thereof.
[0036] In an embodiment, the side-stream 310 comprises any suitable
conduit through which at least a portion of the servicing fluid may
be routed. Nonlimiting examples of such a conduit include a pipe,
tube, the like, or combinations thereof. The side-stream 310 may
comprise a flowbore extending therethrough and may be in fluid
communication with the route of fluid communication 10. In the
embodiment of FIGS. 1 and 2, the side-stream 310 is connected to
the low-pressure-side conduit 200 and is in fluid communication
therewith such that a portion of the fluid flowing via route of
fluid communication 10 may be selectively diverted through the
side-stream 310.
[0037] The side-stream 310 may be of any suitable length and any
suitable diameter. In an embodiment, the side-stream 310 comprises
a conduit of a suitable, known diameter. In an embodiment, the
diameter may be within the range of from about 0.25 inches to about
12 inches, alternatively, from about 0.5 inches to about 4 inches,
alternatively, about 0.5 inches. In an embodiment, the length of
the side-stream 310 may be within the range of from about 1 foot to
about 25 feet, alternatively, from about 1.5 feet to about 20 feet,
alternatively, from about 2 feet to about 10 feet. The side-stream
310 may be characterized as straight, curved, looped, or
combinations thereof and may comprise one or more elbows, bends,
joints, the like, or combinations thereof.
[0038] In an embodiment, the side-stream 310 conduit comprises a
suitable inner surface. In an embodiment, the inner surface of the
side-stream 310 may comprise a suitable roughness, as will be
appreciated by one of skill in the art. For example, in an
embodiment the relative roughness with respect to the pipe diameter
may be in the range of from about 0 to about 0.05, alternatively,
from about 0 to about 0.001.
[0039] In the embodiment of FIG. 2, the FRE meter 300 comprises a
flow-rate meter 330. In an embodiment, the flow-rate meter 330 is
configured to determine the rate at which a fluid is moving through
the flowbore of the side-stream 310. The flow-rate meter 330 may
comprise any type or configuration of device or apparatus suitable
for measuring or determining a rate fluid of flow. Nonlimiting
examples of a suitable types or configurations of a flow-rate
meters include Coriolis mass flow meters, differential pressure
flow meters, electromagnetic flow meters, positive displacement
flow meters, ultrasonic flow meters, turbine or paddlewheel flow
meters, variable area flowmeters, the like, or combinations
thereof.
[0040] In the embodiment of FIG. 2, the FRE meter 300 comprises a
first pressure gauge 320a and a second pressure gauge 320b. In an
embodiment, the first pressure gauge 320a, the second pressure
gauge 320b, or both is configured to measure the pressure of the
fluid at a point within the side-stream 310. The first and second
pressure gauges, 320a and 320b, may comprise any suitable type or
configuration of pressure gauge for determining or monitoring the
pressure of fluid. Non-limiting examples of a suitable pressure
gauge include a hydrostatic gauge, a piston-type gauge, a liquid
column gauge, a mechanical gauge, a diaphragm gauge, a
piezoresistive strain gauge, a capacitive gauge, a magnetic gauge,
a piezoelectric gauge, an optical fiber gauge, a potentiometric
gauge, a resonant gauge, or combinations thereof. The first
pressure gauge 320a, the second pressure gauge 320b, or both may
comprise a suitable output, for example, a display, an electric
signal, a dial, etcetera.
[0041] In an embodiment, the first pressure gauge 320a and the
second pressure gauge 320b may be separated by a known distance. In
the embodiment of FIG. 2, the first pressure gauge 320a and the
second pressure gauge 320b are illustrated as being separated by
distance d. In an embodiment, distance d may be within the range of
from about 1 foot to about 25 feet, alternatively, from about 1.5
feet to about 20 feet, alternatively, from about 2 feet to about 10
feet.
[0042] In an embodiment where the FRE meter 300 comprises one or
more side-stream valves 350, the side-stream valve 350 may comprise
any suitable device or apparatus configured to selectively alter,
adjust, allow, disallow, or combinations thereof, flow of a fluid
therethrough. The side-stream valves 350 may be manually
manipulatable, automatically manipulatable, or combinations
thereof. Suitable valves are generally known to one of skill in the
art.
[0043] In an embodiment where the FRE meter 300 comprises a flow
regulator 340, the flow regulator 340 may comprise any suitable
device or apparatus configured to impede, resist, or prohibit fluid
flow therethrough in a given direction, for example, a check-valve.
In an embodiment, the flow regulator may additionally be configured
to selectively alter, adjust, allow, disallow, or combinations
thereof, flow of a fluid therethrough, for example, a valve.
Suitable devices or apparatuses operable as the flow regulator 340
are generally known to one of skill in the art.
[0044] In an embodiment, the FRE meter 300 disclosed herein may be
employed to independently determine the pipe friction pressure, the
formation response pressure, or other components of the wellhead
pressure.
[0045] In an embodiment, during a wellbore servicing operation
several pressure components may contribute to the total pressure
which may be measured at the wellhead, referred to as the "wellhead
pressure." For example, the wellhead pressure may comprise a
formation response pressure component, a pipe friction pressure
component, a hydrostatic fluid pressure component, and one or more
additional pressure components such as perforation friction. As
used herein, "formation response pressure" refers to the component
of the wellhead pressure attributable to the response of the
subterranean formation into which the servicing fluid is introduced
during a servicing operation. A near-wellbore pressure component
and a formation friction pressure component may contribute to the
formation response pressure. As used herein, "near-wellbore
pressure" generally refers to pressure due to flow restrictions
from the perforations to the fracture such as, for example,
tortuosity. As used herein "formation friction pressure" generally
refers to the pressure due to friction between a servicing fluid
and a fracture as the servicing fluid moves through the fracture.
As used herein, "pipe friction pressure" refers to the pressure due
to pipe friction and "pipe friction" refers to the friction between
the servicing fluid and the inner surface of the pipe string as the
servicing fluid flows through the pipe string. As used herein,
hydrostatic fluid pressure generally refers to the pressure at a
given point within a fluid generally due to the weight of the fluid
above it.
[0046] In an embodiment, determining the pipe friction pressure
independent from one or more other components of the wellhead
pressure may allow the efficiency of the friction reducer included
within the servicing fluid flowing via the route of fluid
communication 10 to be ascertained or calculated. In an embodiment,
knowledge of the efficiency of the friction reducer may allow an
operator to adjust the servicing fluid to achieve a desired level
of friction reducer efficiency.
[0047] In another embodiment, determining the formation response
pressure independent from one or more other components of the
wellhead pressure may provide an operator with valuable information
regarding downhole conditions during the performance of the
servicing operation. In an embodiment, knowledge of downhole
conditions during the servicing operation may allow an operator to
adjust the servicing operation parameters to achieve one or more
desired results.
[0048] In an embodiment, the servicing fluid may comprise any
suitable servicing fluid. Nonlimiting examples of suitable
servicing fluids include a fracturing fluid, a perforating fluid,
an acidizing fluid, a debris removal fluid, the like, or
combinations thereof. In an embodiment, the servicing fluid may
generally comprise a base fluid, a friction reducer, and,
optionally, one or more additional components which may include but
are not limited to proppants, scale inhibitors, biocides,
surfactants, breakers, relative permeability modifiers, or the
like.
[0049] In an embodiment, the base fluid may comprise an aqueous
base fluid, alternatively, a substantially aqueous base fluid. In
an embodiment, a substantially aqueous base fluid comprises less
than about 50% of a nonaqueous component, alternatively less than
about 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10%, 5%, 4%, 3%, 2% or 1%
of a nonaqueous component by weight of the base fluid. In an
embodiment, the base fluid may further comprise an inorganic
monovalent salt, multivalent salt, or combinations thereof.
Nonlimiting examples of salts suitable for use in such a base fluid
include water soluble chloride, bromide and carbonate, hydroxide
and formate salts of alkali and alkaline earth metals, zinc
bromide, and combinations thereof. The salt or salts in the base
fluid may be present in an amount ranging from greater than about
0% by weight of the base fluid to a saturated salt solution. The
water may be fresh water or salt water. Examples of the base fluid
include for are not limited to water produced from the subterranean
formation, flowback water, water transported to the site of the
servicing operation, or both.
[0050] In an embodiment, the base fluid may comprise a nonaqueous
base fluid. In an embodiment, a nonaqueous base fluid may comprise
an oleaginous fluid. Nonlimiting examples of such an oleaginous
olefins, kerosene, diesel oil, fuel oil, synthetic oils, linear or
branched paraffins, olefins, esters, acetals, mixtures comprising
crude oil, derivatives thereof, or combinations thereof.
[0051] In an embodiment, the base fluid may comprise an emulsion of
an aqueous fluid and a nonaqueous fluid. Nonlimiting examples of an
emulsion include an invert emulsion (a water-in-oil emulsion), an
oil-in-water emulsion, a reversible emulsion, or combinations
thereof.
[0052] In an embodiment, the friction reducer may comprise any
suitable friction reducer. In an embodiment the friction reducer
comprises a hydratable friction reducer. The hydratable friction
reducer may be effective to reduce friction between a servicing
fluid comprising the friction reducer and a conduit through which
the servicing fluid is communicated. In an embodiment, the
hydratable friction reducer comprises a polymer. Nonlimiting
examples of a suitable polymer include a polyacrylamide,
polyacrylate, a copolymer of polyacrylamide and polyacrylate, a
copolymer of polyacrylamide and 2-acrylamido-2-methylpropane
sulfonic acid (AMPS), polyethylene oxide, polypropylene oxide, a
copolymer of polyethylene and polypropylene oxide, polysaccharides,
and combinations thereof. Other suitable friction reducers will be
known to those of skill in the art. Examples of suitable friction
reducers that are commercially available are FR-46, FR-56, FR-58,
FR-66, FDP-S944-09, SGA-2, SGA-5, and SGA-18 from Halliburton
Energy Services, Inc.
[0053] In an embodiment, the one or additional components comprise
any suitable servicing fluid components. Suitable servicing fluid
components will be known to those of skill in the art with the aid
of this disclosure. Nonlimiting examples of such components include
a proppant, an acid, an abrasive, a scale inhibitor, a rheology
modifying agent, a resin, a viscosifying agent, a suspending agent,
a breaker, a dispersing agent, a salt, an accelerant, a surfactant,
a relative permeability modifier, a retardant, a defoamer, a
settling prevention agent, a weighting material, a vitrified shale,
a formation conditioning agent, a pH-adjusting agent, or
combinations thereof. These additional components may be included
singularly or in combination.
[0054] In an embodiment, the base fluid, the friction reducer, and
any additional component are blended together in any suitable order
to form the wellbore servicing fluid. In an embodiment, the
attributes of one or more of the components of the servicing fluid
may vary from one servicing operation to another. Further, the
components of a servicing fluid or the relative amounts thereof may
vary throughout the course of a given servicing operation. Not
intending to be bound by theory, the friction reducer employed in a
servicing fluid may vary in compatibility with the other servicing
fluid components between servicing operations or throughout a
servicing operation, thereby causing the friction reducer to vary
as to its effectiveness. For example, the base fluid may comprise
water produced from the subterranean formation; because the
attributes and/or relative amount of the produced water may vary
over the course of the servicing operation, the friction reducer
may vary in compatibility with the base fluid and, as such, the
effectiveness of the friction reducer may vary. Not intending to be
bound by theory, poor dispersion, inversion, hydration, or
combinations thereof of a friction reducer may cause a friction
reducer to exhibit less than a desired level of effectiveness.
[0055] In an embodiment, it may be desirable for a friction reducer
to be about 100, alternatively, 95, 90, 85, 80, 75, or 70%
effective. In an embodiment, where a friction reducer exhibits less
than the desired level of effectiveness, it may be desirable to
adjust the servicing fluid, the route of fluid communication of the
servicing fluid; or combinations thereof to improve dispersion,
inversion, hydration, or combinations thereof and thereby increase
friction reducer effectiveness.
[0056] Disclosed herein is an embodiment of a method of servicing a
subterranean formation. In various embodiments, the servicing
operation may comprise a fracturing operating, a perforating and/or
hydrajetting operation, an acidizing operation, or combinations
thereof. In the embodiment of FIG. 3, the servicing method 50
generally comprises the steps of determining an ideal percent
friction reduction for a given friction reducer 500, communicating
a subterranean formation servicing fluid to the subterranean
formation 510, and determining an actual percent friction reduction
520. In an embodiment, the subterranean formation servicing method
optionally comprises calculating a percent effectiveness of the
friction reducer 530. In an embodiment, a servicing method
optionally comprises adjusting at least one parameter of the
servicing operation in response to the effectiveness of the
friction reducer 540.
[0057] In an embodiment, determining the ideal percent friction
reduction 500, % FR.sub.Ideal, may comprise any suitable method. As
used herein, the term "ideal percent friction reduction" refers to
the ideal percentage by which the pipe friction is reduced by a
friction reducer. The % FR.sub.Ideal may be determined
analytically, experimentally, or combinations thereof.
[0058] In an embodiment, determining the % FR.sub.Ideal 500 may
comprise an experimental determination. For a fluid flowing from a
first point, Point A, to a second point, Point B, in a pipe,
assuming that the diameter of the pipe remains constant, that the
elevation of the pipe between Point A and Point B is unchanged, and
that the velocity of the fluid is constant along the pipe, the
pressure at Points A and B may be generally described in that the
pressure at Point B, P.sub.B, is equal to the pressure at Point A,
P.sub.A, minus the pipe friction pressure, P.sub.Pipe. Therefore,
assuming the foregoing, the pipe friction pressure will be equal to
the difference in the pressure at Point A and the pressure at Point
B as shown in equation (I):
P.sub.Pipe=P.sub.A-P.sub.B Equation (I).
[0059] In an embodiment, determining the % FR.sub.Ideal 500 may
generally comprise determining the pipe friction pressure for a
fluid (e.g., fresh water) that does not comprise a friction
reducer, P.sub.Initial, and determining the pipe friction pressure
for fresh water comprising a friction reducer at its ideal
effectiveness, P.sub.Ideal. In an embodiment, an experimental
determination of the % FR.sub.Ideal may also generally comprise
comparing the P.sub.Initial with the P.sub.Ideal.
[0060] In an embodiment, determining the P.sub.Initial comprises
observing the difference in P.sub.A and P.sub.B for fresh water
from which a friction reducer is absent while flowing through a
conduit (e.g., a pipe, a test loop, a pressure loop, or the like).
In an embodiment, determining the P.sub.Ideal comprises observing
the difference in P.sub.A and P.sub.B for the same fresh water or a
substantially similar fresh water with a friction reducer while
flowing through the same or a similar conduit.
[0061] In an alternative embodiment, determining the P.sub.Initial
comprises calculating the change in pressure for a fluid (e.g.,
fresh water) from which a friction reducer is absent at about
ambient conditions (e.g., about 25.degree. C. and about 1 atm.)
over a given portion of a flow conduit of length L according to
equation (II-A):
P Initial = .rho. V 2 Lf 2 g c D Equation ( II - A )
##EQU00001##
where .rho. is the density of the fluid at about 25.degree. C. and
about 1 atm., V is the velocity of the fluid, g.sub.c is the
gravitational constant, D is the diameter of the flow conduit, and
where f is the friction factor. The friction factor, f, may be
calculated according to equation (III) for a fully turbulent fluid
flow:
f = { - 2 log [ / D 3.7 - 5.02 Re log ( / D 3.7 + 14.5 Re ) ] } - 2
Equation ( III ) ##EQU00002##
where .epsilon. is the pipe roughness, D is the diameter of the
flow conduit, and Re is the Reynolds number as calculated for the
fluid at about 25.degree. C. and about 1 atm. (Shacham, M., Isr.
Chem. Eng., 8, 7E (1976)).
[0062] As will be appreciated by one of skill in the art, one or
more of the time that the friction reducer is in contact with an
aqueous fluid, temperature of the fluid, the solute (e.g., a salt)
concentration of the fluid, the combinations of solutes of the
fluid, the soluble and insoluble organic materials of the fluid,
the particulates of the fluid, the pressure of the fluid, or
combinations thereof may vary the effectiveness of the friction
reducer utilized in such a fluid. In an embodiment, the fluid for
which the pipe friction will be determined comprises freshwater.
Not intending to be bound by theory, utilizing freshwater to
determine the pipe friction pressure may minimize the opportunity
for incompatibility of the friction reducer; as such, the friction
reducer may be fully or substantially hydrated (and thereby, not
intending to be bound by theory, maximally effective). In an
embodiment, the friction reducer may be contacted with the fluid
for 20 seconds under appreciable flow or shear to ensure the
friction reducer may be fully or substantially hydrated (and
thereby, not intending to be bound by theory, maximally effective).
In an embodiment, the maximum effectiveness of a given hydratable
friction reducer may be determined where, for example, the friction
reducer has been in contact with a fluid for a given amount of
time, the fluid is at a given temperature, the fluid is at a given
solute (e.g., a salt) concentration, the fluid is at a given
pressure, or combinations thereof.
[0063] In an embodiment, the presence of the friction reducer in
the fluid may reduce the amount of pipe friction. Therefore, the
P.sub.Ideal may be less than the P.sub.Initial. By comparing the
P.sub.Ideal and the P.sub.Initial, the percent by which the pipe
friction is reduced, the % FR.sub.Ideal, may be calculated
according to equation (IV):
% FR Ideal = ( 1 - P Ideal P Initial ) .times. 100 % . Equation (
IV ) ##EQU00003##
[0064] In an alternative embodiment, determining the % FR.sub.Ideal
500 may comprise an analytical determination. Such an analytical
determination of the % FR.sub.Ideal may generally comprise
calculating, deriving, or extrapolating % FR.sub.Ideal,
P.sub.Ideal, P.sub.Initial, or combinations thereof according to a
suitable mathematical relationship.
[0065] In an embodiment, % FR.sub.Ideal may be determined prior to
the servicing operation, at a site removed from the servicing
operation, or both. For example, % FR.sub.Ideal may be determined
in a laboratory setting prior to a given servicing operation. In an
embodiment, where a % FR.sub.Ideal has been determined for a given
friction reducer, the previously determined % FR.sub.Ideal may be
employed. For example, a % FR.sub.Ideal utilized in a prior or
separate servicing operation may be employed as the % FR.sub.Ideal
for another servicing operation. It is specifically contemplated
that the % FR.sub.Ideal associated with a friction reducer may be
known or may be derived from other known data and, as such, need
not be determined for each and every servicing operation.
[0066] In an embodiment, the servicing method 50 comprises
communicating a servicing fluid comprising the friction reducer the
subterranean formation 510. In an embodiment, the servicing fluid
may be communicated to the subterranean formation 102 via a
suitable route of fluid communication, for example, referring to
FIG. 1, route of fluid communication 10.
[0067] In an embodiment, the components of the servicing fluid may
be provided from the one or more storage vessels 230 to the
blending pump 210 via the one or more supply lines 220.
Alternatively, one or more of the components may be introduced
directly into the blending pump 210. The servicing fluid components
may be introduced at any suitable rate, in any suitable order, in
any suitable ratio, as will be appreciated by one of skill in the
art. When mixed, the servicing fluid may be routed from the
blending pump 210 to the one or more pressurizing pumps 190 via the
low-pressure-side conduit 200. A portion of the servicing fluid may
be routed through each of the one or more pressurizing pumps 190,
thereby increasing the pressure of the servicing fluid moving
within the route of fluid communication 10. As will be appreciated
by one of skill in the art, the servicing fluid may be pressurized
to a suitable pressure, dependent upon the servicing operation
being performed. The pressurized servicing fluid may be routed from
the one or more pressurizing pumps 190 through the manifold 180,
high-pressure-side conduit, wellhead 160, pipe string 150, and
wellbore servicing apparatus 140 to the subterranean formation 102.
A portion of the servicing fluid may flow into and/or through the
subterranean formation 102. Additionally, a portion of the
servicing fluid may be circulated through the wellbore 114.
[0068] In an embodiment, the servicing method 50 may comprise
determining the actual percent friction reduction, % FR.sub.Actual
520. In an embodiment, % FR.sub.Actual may be determined by any
suitable method. As used herein, the term "actual percent friction
reduction" refers to the actual percentage by which the pipe
friction of a servicing fluid is reduced by a given friction
reducer.
[0069] In an embodiment, determining the % FR.sub.Actual 520 may
comprise diverting at least a portion of the servicing fluid
through the side-stream 310, measuring the velocity of the diverted
servicing fluid, measuring a change in pressure of the diverted
servicing fluid over a given distance, or combinations thereof.
[0070] In an embodiment, at least a portion of the servicing fluid
flowing via the route of fluid communication may be diverted into
the side-stream 310 of the FRE meter 300. In an embodiment, the
portion of the servicing fluid that is diverted may be in the range
of from about less than 1% to about 99% of the total volume of
servicing fluid, alternatively, from about 1% to about 20% of the
total volume of servicing fluid, alternatively, from about 5% to
about 15% of the total volume of servicing fluid, alternatively,
about 10% of the total volume of servicing fluid. In an embodiment,
the percentage of the total volume of the servicing fluid diverted
into the side-stream 310 may be adjusted by opening or closing the
side-stream valves 350.
[0071] In an embodiment, the average fluid velocity of the portion
of the servicing fluid diverted into the side-stream 310 may be
determined from the flow-rate meter 330. In an embodiment, the
average fluid velocity of the fluid flowing through the side-stream
may be any suitable velocity. In an embodiment, the average fluid
velocity of the fluid flowing through the side-stream may be in the
range of from about 1 to about 200 feet per second (fps),
alternatively, about 10 to about 100 fps, alternatively, about 20
to about 60 fps. In an embodiment, the average fluid velocity of
the fluid flowing through the side-stream 310 may be adjusted, for
example, as by manipulation of one or more of the side-stream
valves 350. In an embodiment, adjustment of one or more of the
side-stream valves 350 may be manual, automatic, or combinations
thereof. For example, an operator viewing the average fluid
velocity of the fluid within the side-stream 310 may manually
adjust the side-stream valve to achieve a desirable average fluid
velocity.
[0072] Alternatively, the side-stream valves 350 may be
automatically adjusted in response to the velocity of the fluid in
the side-stream 310 as measured by the flow-rate meter (e.g., via a
suitable connection between the flow-rate meter 330 and the
side-stream valves 350). In an embodiment, the velocity of the
fluid flowing via the side-stream may be employed in comparing the
ideal percent friction reduction for the friction reducer, %
FR.sub.Ideal, to the actual friction reduction for that friction
reducer, % FR.sub.Actual. For example, because % FR.sub.Ideal may
depend largely on fluid velocity and shear rate, it may be
advantageous, alternatively, necessary, to know the fluid velocity
at which % FR.sub.Actual occurs to ensure that % FR.sub.Actual is
compared to the appropriate % FR.sub.Ideal, which is discussed in
greater detail below.
[0073] In an embodiment, the flow of the servicing fluid through
the side-stream 310 may be characterized as a turbulent flow. As
will be appreciated by one of skill in the art, turbulent flow is a
flow regime that may be characterized by secondary flows
appreciable in magnitude compared to the primary flow direction,
eddies, and apparent randomness. Conversely, non-turbulent flow may
be referred to as laminar flow. The Reynolds number, a
dimensionless number that relates the ratio of inertial forces to
viscous forces, often indicates whether a flow regime will be
characterized as turbulent or laminar for a given flow geometry.
Generally Newtonian fluids flowing in pipes with circular
cross-sections, flow regimes where the Reynolds number is greater
than about 2000 may be characterized as turbulent flow while flow
regimes where the Reynolds number is less than about 2000 may be
characterized as laminar flow.
[0074] In an embodiment, the change in the pressure of the portion
of the servicing fluid flowing over distance d within the FRE meter
300 is determined using the first pressure gauge 320a and the
second pressure gauge 320b. Not intending to be bound by theory, as
discussed above, for a fluid flowing from a first point, Point A,
to a second point, Point B, in a pipe, assuming that the diameter
of the pipe remains constant, that the elevation of the pipe
between Point A and Point B is unchanged, and that the velocity of
the fluid is constant along the pipe, the pressure at Point A
(e.g., as measured by the first pressure gauge 320a) and the
pressure at Point B (e.g., as measured by the second pressure gauge
320b) may be generally described in that the pressure at Point B,
P.sub.B, is equal to the pressure at Point A, P.sub.A, minus the
pipe friction pressure, P.sub.Pipe. Therefore, assuming the
foregoing, the pipe friction pressure may be calculated according
to equation (I):
P.sub.Pipe=P.sub.A-P.sub.B Equation (I).
[0075] In an embodiment, determining % FR.sub.Actual 520 may
comprise determining the pipe friction pressure for the servicing
fluid from which the friction reducer is absent, P.sub.0;
determining the pipe friction pressure for the servicing fluid
comprising a friction reducer, P.sub.Actual; and comparing the
P.sub.0 with the P.sub.Actual.
[0076] In an embodiment, determining the P.sub.0 may comprise
observing the difference in P.sub.A and P.sub.B for a servicing
fluid from which a friction reducer is absent. In an embodiment,
determining the P.sub.Actual may comprise observing the difference
in P.sub.A and P.sub.B for a servicing fluid comprising a friction
reducer. By comparing the P.sub.0 and the P.sub.Actual, the %
FR.sub.Actual may be calculated according to equation (V):
% FR Actual = ( 1 - P Actual P 0 ) .times. 100 % . Equation ( V )
##EQU00004##
[0077] In an alternative embodiment, the P.sub.0 may be estimated,
calculated, or otherwise determined based upon a prior known value,
for example, based upon the value of P.sub.Initial used in
determining % FR.sub.Ideal as described above.
[0078] In another embodiment, P.sub.0 may be calculated (similar to
the calculation of P.sub.Initial given above) by equation
(II-B):
P 0 = .rho. V 2 Lf 2 g c D Equation ( II - B ) ##EQU00005##
where L is the length of the flow conduit, .rho. is the density of
the fluid at 25.degree. C. and about 1 atm., V is the velocity of
the fluid, g.sub.c is the gravitational constant, D is the diameter
of the flow conduit, and where f is the fiction factor. The
friction factor, f, may be calculated according to equation (III)
for a fully turbulent fluid flow:
f = { - 2 log [ / D 3.7 - 5.02 Re log ( / D 3.7 + 14.5 Re ) ] } - 2
Equation ( III ) ##EQU00006##
where .epsilon. is the pipe roughness, D is the diameter of the
flow conduit, and Re is the Reynolds number as calculated for the
fluid at about 25.degree. C. and about 1 atm. (Shacham, M., Isr.
Chem. Eng., 8, 7E (1976)).
[0079] In an embodiment, the servicing method 50 comprises
calculating the effectiveness of the friction reducer 530. In an
embodiment, calculating the effectiveness of the friction reducer
530 comprises comparing the ideal percent friction reduction for
the friction reducer, % FR.sub.Ideal, to the actual friction
reduction for that friction reducer, % FR.sub.Actual. By comparing
% FR.sub.Actual and % FR.sub.Ideal, the effectiveness, expressed as
a percent, may be calculated according to equation (VI):
Effectiveness = % FR Actual % FR Ideal 100 % . Equation ( VI )
##EQU00007##
[0080] In an embodiment, the FRE meter 300 and the methods
disclosed herein may yield a measure of friction reduction and/or
friction reducer effectiveness at a time from about 10 to about 60
seconds after the friction reducer has been injected into the
servicing fluid (e.g., the FRE meter measures the pipe friction
pressure at a point downstream from where the components of the
servicing fluid are first mixed, as shown in FIG. 1). The FRE meter
300 and the methods disclosed herein may yield a measure of
friction reduction and/or friction reducer effectiveness that is
instantaneous and/or in real-time.
[0081] In an embodiment, the FRE Meter 300 allows for the
determination of the pipe friction pressure independent from one or
more other components of the wellhead pressure. In an embodiment
where the pipe friction pressure is known, it may be possible to
calculate or monitor changes in one or more other components of the
wellhead pressure. For example, it may be possible to calculate the
formation response pressure component, the hydrostatic fluid
pressure component, or one or more additional pressure components
independent from the wellhead pressure.
[0082] In an embodiment, the servicing method 50 further comprises
adjusting at least one parameter of the servicing operation 540. In
an embodiment, adjusting at least one parameter of a servicing
operation 540 may increase the efficiency of a friction reducer,
effect a change in the servicing operation, or combinations
thereof.
[0083] As discussed above, a given friction reducer may vary as to
its effectiveness dependent upon the servicing fluid in which it is
used, and/or other components present within the servicing fluid.
As such, it may be desirable to adjust one or more parameters of
the servicing operation to achieve a desirable friction reducer
effectiveness. In an embodiment where the effectiveness of a
friction reducer is less than desired, an operator may adjust one
or more parameters of the servicing operation to increase the
effectiveness of the friction reducer.
[0084] As discussed above, the formation response pressure may
indicate the presence or absence of a condition within a downhole
portion of the wellbore and/or the subterranean formation. As such,
it may be desirable to adjust one or more parameter of the
servicing operation where the formation response pressure
so-indicates.
[0085] In an embodiment adjusting one or more parameters of the
servicing operation may comprise altering, changing, adjusting the
composition of the servicing fluid, for example, by altering,
changing, adjusting the base fluid of the servicing fluid, one or
more components of the servicing fluid, the friction reducer used
therein, or combinations thereof in order to achieve a desired
effectiveness. For example, the operator might adjust or alter the
servicing fluid by changing the amount or proportion of some
component, adding a component, altering a pH, changing the amount,
type, or proportion of friction reducer used, using a different
friction reducer, using a combination of friction reducers, or
combinations thereof.
[0086] In an embodiment, adjusting at least one parameter of the
servicing operation may comprise altering, changing, or adjusting
the route of fluid communication of the servicing fluid in response
to the effectiveness of the friction reducer. For example, the
operator might alter the amount of time for hydration of the
friction reducer, alter the amount of time prior to communicating
the servicing fluid to the subterranean formation, alter the amount
of time the servicing fluid is mixed, alter the pressure at which
the servicing fluid is communicated to the subterranean formation,
alter the volume of servicing fluid communicated to the
subterranean formation, or combinations thereof.
[0087] In an embodiment, one or more of the steps of the servicing
method disclosed herein may be implemented in software on one or
more computers or other computerized components having a processor,
user interface, microprocessor, memory, and other associated
hardware and operating software. Software may be stored in tangible
media and/or may be resident in memory on the computer Likewise,
input and/or output from the software, for example ratios,
percentages, comparisons, and results may be stored in a tangible
media, computer memory, hardcopy such a paper printout, or other
storage device.
[0088] In an embodiment, data (e.g., pressures, pressure
differentials, etc.) obtained from the performance of the foregoing
methods may be input into a computer automatically via a suitable
interface; alternatively, data may be input by a user or operator.
Calculations and comparisons (e.g., percent effectiveness, ideal
percent friction reduction, actual percent friction reduction) may
be performed by a suitable computer or computerized component;
alternatively, calculations and comparisons may be performed by a
user or operation. A suitable computer or computerized component
may effect changes to the servicing operation (e.g., changes to the
servicing fluid, the route of fluid communication, or both)
responsive to a calculation, comparison, or both (e.g., a
comparison of the actual effectiveness of a friction reducer with
the desired effectiveness of the friction reducer) via a suitable
interface (e.g., electric, electronic, mechanical, or combinations
thereof); alternatively, the results of a calculation or comparison
may be provided to a user or operator via a suitable display (e.g.,
a print-out, a screen, etc) and the user or operator may decide
whether changes to the servicing operation are desirable and, if so
effect one or more changes to the servicing operation via one or
more suitable control means (a dial, switch, level, etc).
[0089] In an embodiment, the devices, systems, and/or methods of
the instant disclosure may be employed to introduce a fracture into
a subterranean formation (e.g., a fracturing operation).
Hydrocarbon-producing wells often may be stimulated by hydraulic
fracturing operations. In an embodiment of a fracturing operation,
a fracturing fluid, such as a particle laden fluid, is pumped at
relatively high-pressure into a wellbore. The fracturing fluid may
be introduced into a portion of a subterranean formation at a
sufficient pressure and/or velocity and/or initiate, create,
extend, or enhance at least one fracture therein. Proppants, such
as grains of sand, may be mixed with the fracturing fluid to keep
the fractures open so that hydrocarbons may be produced from the
subterranean formation and flow into the wellbore. Hydraulic
fracturing may desirably create high-conductivity fluid
communication between the wellbore and the subterranean
formation.
[0090] In an embodiment, the method of introducing a fracture into
a subterranean formation comprises preparing a fracturing fluid. In
such an embodiment, the servicing fluid comprises a fracturing
fluid comprising a base fluid, a proppant, a hydratable friction
reducer, and, optionally, additives.
[0091] In an embodiment, the base fluid may comprise water. The
water may be potable, non-potable, untreated, partially treated,
treated water, or combinations thereof. In an embodiment, the water
may be produced water that has been extracted from the wellbore
while producing hydrocarbons form the wellbore. The produced water
may comprise dissolved and/or entrained organic materials, salts,
minerals, paraffins, aromatics, resins, asphaltenes, and/or other
natural or synthetic constituents that are displaced from a
hydrocarbon formation during the production of the hydrocarbons. In
an embodiment, the water may be flowback water that has previously
been introduced into the wellbore during wellbore servicing
operation. The flowback water may comprise some hydrocarbons,
gelling agents, friction reducers, surfactants and/or remnants of
wellbore servicing fluids previously introduced into the wellbore
during wellbore servicing operations. The water may further
comprise local surface water contained in natural and/or manmade
water features (such as ditches, ponds, rivers, lakes, oceans,
etc.). Still further, the water may comprise water stored in local
or remote containers. The water may be water that originated from
near the wellbore and/or may be water that has been transported to
an area near the wellbore from any distance. In some embodiments,
the water may comprise any combination of produced water, flowback
water, local surface water, and/or container stored water.
[0092] In an embodiment, proppant, the base fluid, the hydratable
friction reducer, and, optionally, the additives are fed into the
blending pump 210 via supply lines 220. The blending pump 210 mixes
solid and fluid components to achieve a well-blended fracturing
fluid. The mixing conditions of the blending pump 210, including
time period, agitation method, pressure, and temperature, may be
chosen by one of ordinary skill in the art with the aid of this
disclosure to produce a homogeneous blend having a desirable
composition, density, and viscosity. In alternative embodiments,
however, sand or proppant, water, friction reducer, and/or
additives may be premixed and/or stored in a storage tank.
[0093] In an embodiment, the method of introducing a fracture into
a subterranean formation comprises determining the ideal percent
friction reduction, % FR.sub.Ideal, for a given friction reducer.
As disclosed above, the % FR.sub.Ideal may be determined by
experimental means. For example, it may be determined that a given
friction reducer ideally may reduce pipe friction by about up to
80% (% FR.sub.Ideal=80%) at about 15-25 seconds after injection of
the friction reducer into the base fluid.
[0094] In an embodiment, the method of introducing a fracture into
a subterranean formation comprises communicating the fracturing
fluid to a subterranean formation via a suitable route of fluid
communication, for example, route of fluid communication 10
disclosed herein. In an embodiment, the pressurizing pumps 190 may
pressurize the fracturing fluid to a pressure suitable for delivery
into the wellhead 160. For example, the pressurizing pumps 190 may
increase the pressure of the fracturing fluid to a pressure of up
to about 20,000 psi or higher. In an embodiment, the fracturing
fluid may be combined to achieve a total fluid flow rate that
enters the wellhead 160 at a total flow of between about 1 BPM to
about 200 BPM, alternatively from between about 50 BPM to about 150
BPM, alternatively about 100 BPM.
[0095] During the communication of the fracturing fluid, a portion
of the fracturing fluid may be diverted from the route of fluid
communication through an FRE meter so as to determine the actual
percent friction reduction, % FR.sub.Actual. In an embodiment, to
determine % FR.sub.Actual, the pipe friction pressure for the
servicing fluid from which the friction reducer is absent, P.sub.0,
may be calculated by equation (II-B):
P 0 = .rho. V 2 Lf 2 g c D Equation ( II - B ) ##EQU00008##
where L is the length of the flow conduit, .rho. is the density of
the fluid at 25.degree. C. and about 1 atm., V is the velocity of
the fluid, g.sub.c is the gravitational constant, D is the diameter
of the flow conduit, and where f is the fiction factor. The
friction factor, f, may be calculated according to equation (III)
for a fully turbulent fluid flow:
f = { - 2 log [ / D 3.7 - 5.02 Re log ( / D 3.7 + 14.5 Re ) ] } - 2
Equation ( III ) ##EQU00009##
[0096] where .epsilon. is the pipe roughness, D is the diameter of
the flow conduit, and Re is the Reynolds number as calculated for
the fluid at about 25.degree. C. and about 1 atm. (Shacham, M.,
Isr. Chem. Eng., 8, 7E (1976)). P.sub.Actual may be determined by
measuring the pipe pressure of the servicing fluid having the
friction reducer present as the servicing fluid flows via the FRE
meter. Therefore, as disclosed above, comparing P.sub.0 with
P.sub.Actual yields the actual percent by which the friction
reducer reduces pipe friction. For example, it may be determined
that a given friction reducer actually reduces pipe friction by 60%
(% FR.sub.Actual=60%) at about 15-25 seconds after injection into
the fracturing fluid. As disclosed above, comparing the %
FR.sub.ideal with the % FR.sub.Actual yields the percent
effectiveness. For example, a friction reducer that ideally reduces
pipe friction by 80% and actually reduces pipe friction by 60%
would be 75% effective.
[0097] In an embodiment where the percent effectiveness of the
friction reducer is less than a desired percent effectiveness, an
operator may choose to adjust the composition of the servicing
fluid, the route of fluid communication or both. For example, if an
operator desired 90% effectiveness, where a friction reducer
performed at 75% effectiveness, the operator might choose to adjust
the composition of the servicing fluid, the route of fluid
communication, or combinations thereof. In an embodiment, adjusting
the composition of the servicing fluid, the route of fluid
communication, or combinations thereof may increase the
effectiveness of the friction reducer by, not intending to be bound
by theory, increasing the hydration, inversion, dispersion, or
combinations thereof of the friction reducer.
[0098] In an embodiment, the operator may adjust the composition of
the servicing fluid by altering the amount of friction reducer,
altering the type of friction reducer, adding second friction
reducer, adding a component to the base fluid, subtracting a
component from the base fluid, altering the composition of the base
fluid, or combinations thereof. In an embodiment, the operator may
adjust the route of fluid communication by altering the amount of
time for hydration of the friction reducer, altering the amount of
time prior to communicating the servicing fluid to the subterranean
formation, altering the amount of time the servicing fluid is
mixed, altering the pressure at which the servicing fluid is
communicated to the subterranean formation, altering the volume of
servicing fluid communicated to the subterranean formation, or
combinations thereof.
EXAMPLES
[0099] The embodiments having been generally described, the
following examples are given as embodiments of the disclosure and
to demonstrate the practice and advantages thereof. It is to be
understood that the examples are presented herein as a means of
illustration and are not intended to limit the specification or the
claims.
[0100] In each of the following examples, an FRE meter, for
example, similar to FRE meter 300 disclosed herein, was used, for
example, as by the methods disclosed herein, to measure friction
reduction and/or the effectiveness of a friction reducer. The
results of these examples are shown in FIG. 4.
Example 1
[0101] 1 gpt (gallons per thousand gallons) of FR-56 was injected
into Duncan tap water flowing at a nominal rate of 28 gallons per
minute through a 0.56-inch, smooth pipe. Approximately 20 seconds
after the friction reducer was injected, the instantaneous friction
reduction was measured at about 72%, and the friction reduction
effectiveness was 100%. In an embodiment, this may represent %
FR.sub.Ideal.
Example 2
[0102] 1 gpt of FR-56 was injected into Duncan tap water containing
16 wt % CaCl (calcium chloride) flowing at a nominal rate of 28
gallons per minute through a 0.56-inch, smooth pipe. Approximately
20 seconds after the friction reducer was injected, the
instantaneous friction reduction was measured at about 30%, and the
friction reduction effectiveness was 42%.
Example 3
[0103] 1 gpt of FR-46 was injected into untreated Velma field water
flowing at a nominal rate of 10 gallons per minute through a
0.56-inch, smooth pipe. Approximately 20 seconds after the friction
reducer was injected, the instantaneous friction reduction was
measured at about 48%, and the friction reduction effectiveness was
67%.
[0104] At least one embodiment is disclosed and variations,
combinations, and/or modifications of the embodiment(s) and/or
features of the embodiment(s) made by a person having ordinary
skill in the art are within the scope of the disclosure.
Alternative embodiments that result from combining, integrating,
and/or omitting features of the embodiment(s) are also within the
scope of the disclosure. Where numerical ranges or limitations are
expressly stated, such express ranges or limitations should be
understood to include iterative ranges or limitations of like
magnitude falling within the expressly stated ranges or limitations
(e.g., from about 1 to about 10 includes, 2, 3, 4, etc.; greater
than 0.10 includes 0.11, 0.12, 0.13, etc.). For example, whenever a
numerical range with a lower limit, R.sub.l, and an upper limit,
R.sub.u, is disclosed, any number falling within the range is
specifically disclosed. In particular, the following numbers within
the range are specifically disclosed:
R=R.sub.l+k*(R.sub.u-R.sub.l), wherein k is a variable ranging from
1 percent to 100 percent with a 1 percent increment, i.e., k is 1
percent, 2 percent, 3 percent, 4 percent, 5 percent, . . . 50
percent, 51 percent, 52 percent, . . . , 95 percent, 96 percent, 97
percent, 98 percent, 99 percent, or 100 percent. Moreover, any
numerical range defined by two R numbers as defined in the above is
also specifically disclosed. Use of the term "optionally" with
respect to any element of a claim means that the element is
required, or alternatively, the element is not required, both
alternatives being within the scope of the claim. Use of broader
terms such as comprises, includes, and having should be understood
to provide support for narrower terms such as consisting of,
consisting essentially of, and comprised substantially of.
Accordingly, the scope of protection is not limited by the
description set out above but is defined by the claims that follow,
that scope including all equivalents of the subject matter of the
claims. Each and every claim is incorporated as further disclosure
into the specification and the claims are embodiment(s) of the
present invention. The discussion of a reference in the disclosure
is not an admission that it is prior art, especially any reference
that has a publication date after the priority date of this
application. The disclosure of all patents, patent applications,
and publications cited in the disclosure are hereby incorporated by
reference, to the extent that they provide exemplary, procedural or
other details supplementary to the disclosure.
* * * * *