U.S. patent application number 15/891155 was filed with the patent office on 2018-06-14 for completion fluid friction reducer.
This patent application is currently assigned to Noles Intellectual Properties, LLC. The applicant listed for this patent is Noles Intellectual Properties, LLC. Invention is credited to Jerry W. Noles, Alex J. Watts.
Application Number | 20180163115 15/891155 |
Document ID | / |
Family ID | 59561253 |
Filed Date | 2018-06-14 |
United States Patent
Application |
20180163115 |
Kind Code |
A1 |
Noles; Jerry W. ; et
al. |
June 14, 2018 |
COMPLETION FLUID FRICTION REDUCER
Abstract
A method and composition for reducing a coefficient of friction
are disclosed. In an embodiment, a method for reducing a
coefficient of friction between two surfaces in a borehole includes
preparing a mixture comprising a primary lubricating agent, a
primary surfactant, a spreading agent, and an aqueous fluid. The
method also includes pumping the mixture into the borehole such
that the mixture contacts the two surfaces and reduces the
coefficient of friction for the two surfaces.
Inventors: |
Noles; Jerry W.; (Blanchard,
OK) ; Watts; Alex J.; (Rayville, LA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Noles Intellectual Properties, LLC |
Washington |
OK |
US |
|
|
Assignee: |
Noles Intellectual Properties,
LLC
Washington
OK
|
Family ID: |
59561253 |
Appl. No.: |
15/891155 |
Filed: |
February 7, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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15045001 |
Feb 16, 2016 |
9914867 |
|
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15891155 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E21B 41/00 20130101;
C10M 2207/281 20130101; C10M 2213/062 20130101; C09K 8/035
20130101; C10N 2030/06 20130101; C10M 2209/104 20130101; C10M
2215/082 20130101; C10M 2207/18 20130101; C10M 173/00 20130101;
C10M 2207/126 20130101; C10N 2050/011 20200501; C09K 2208/34
20130101; C10M 2203/1006 20130101; C10M 2209/109 20130101; C10M
2215/08 20130101; E21B 7/046 20130101; C09K 2208/28 20130101; C10M
173/02 20130101; C10M 2209/104 20130101; C10M 2209/109
20130101 |
International
Class: |
C09K 8/035 20060101
C09K008/035; C10M 129/70 20060101 C10M129/70; C10M 145/38 20060101
C10M145/38; C10M 105/24 20060101 C10M105/24 |
Claims
1. A pumpable friction reducing fluid composition comprising: a
primary lubricating agent; a primary surfactant; a spreading agent;
and an aqueous fluid.
2. The composition of claim 1, wherein the primary lubricating
agent comprises a tall oil fatty acid, a tallow fatty acid, or a
combination thereof.
3. The composition of claim 1, wherein the primary lubricating
agent comprises palmitic acid, palmitoleic acid, stearic acid,
oleic acid, linoleic acid, myristic acid, linolenic acid, or a
combination thereof.
4. The composition of claim 1, wherein the primary surfactant
comprises a nonionic surfactant comprising a hydrophile/lipophile
balance between 9 to 14 and a molecular weight in a range of about
200 to about 600.
5. The composition of claim 1, wherein the primary surfactant
comprises a poly(ethylene glycol) monooleate, poly(ethylene glycol)
dioleate, poly(ethylene glycol) monolaurate, poly(ethylene glycol)
dilaurate, or a combination thereof.
6. The composition of claim 1, wherein the spreading agent
comprises a transesterified lipid.
7. The composition of claim 1, wherein the spreading agent
comprises methyl canolate, methyl caprate, methyl caprylate, methyl
coconate, methyl lardate, methyl laurate, methyl myristate, methyl
oleate, methyl palm kernelate, methyl palmitate, methyl soyate,
methyl stearate, methyl tallowate, or a combination thereof.
Description
RELATED APPLICATIONS
[0001] This application is a divisional application of pending U.S.
Nonprovisional patent application Ser. No. 15/045,001, filed on
Feb. 16, 2016, which is specifically incorporated by reference in
its entirety herein.
BACKGROUND
Field of the Invention
[0002] This invention relates to the field of completion fluids for
drilling applications, and more particularly to the field of
reducing the friction between similar or dissimilar surfaces using
an aqueous-based completion fluid disposed between the similar or
dissimilar surfaces.
Background of the Invention
[0003] Drilling horizontally within an oil and gas reservoir can
potentially produce a more productive well, because a horizontal
well may allow for access to larger areas of an oil- and
gas-bearing formation. As such, the longer the horizontal section
of the well, the more productive the well may be. For this reason,
it has become increasingly common to drill horizontally in many
oil- and gas-bearing formations as well as utility and mining
applications.
[0004] Increasing the length of the horizontal section of a
borehole may be difficult when the length of the horizontal section
surpasses the length of the vertical section. Further, the
insertion of conduits, such as a drill pipe, may become
increasingly difficult as the horizontal section is lengthened. For
example, as the drill pipe is pushed further into the borehole, the
amount of contact between it and other surfaces increases, and thus
so would the amount of friction between the drill pipe and the
other surfaces. Thus, the ability to push or rotate the drill pipe
in the wellbore may become limited as the friction increases.
Friction may also be present between a conduit and wellbore
tools/wellbore materials inserted into the conduit. For example,
wires or cables may be pushed or pulled into a conduit only so long
as the amount of friction between the wires/cables and the conduit
is low enough to allow for the wires/cables to be pushed or pulled.
As discussed above, friction between two similar or dissimilar
surfaces may increase faster in horizontal sections of a conduit
relative to vertical sections of the conduit.
[0005] A specific example of the difficulty of drilling a
horizontal section may be illustrated by the process of drilling
bridge plugs from the casing. The drilling of bridge plugs is often
performed with a fluid motor and bit on the end of a section of
coiled tubing. An aqueous-based fluid may be pumped down the
tubing, through the motor and bit, and back up the annulus inside
the casing. The friction between a section of coiled tubing and the
casing in the horizontal section of the borehole may become equal
to the force available to move the coiled tubing along the
horizontal section, at which point further drilling may not be
possible.
[0006] As discussed, one method of reducing friction in oil, gas,
and mining operations is to push a conduit with a mechanism that
would drive the conduit into the borehole or well. This pushing may
be accomplished by any mechanism that is capable of delivering a
sufficient amount of force to the conduit such that the conduit is
pushed into the borehole. This may be referred to as "snubbing the
pipe." In utility boring or mining operations, cables may be
attached to the drill string to pull the conduits into or out of
the borehole so as to overcome the friction between the conduit and
the borehole. Further, in some horizontal drilling applications,
rotating the conduit at a high enough RPM may reduce the amount of
frictional contact between the conduit and any surfaces it
contacts. This is commonly done during drilling and boring
operations and may allow for longer horizontal sections to be
drilled. However, not all conduits can be rotated. For example,
when a jointed pipe is used, the pipe may be rotated along with the
bit, and the friction resisting movement of the pipe along the
borehole may be decreased. However, when coiled tubing is used, the
coiled tubing cannot be rotated, and the friction resisting
movement of the tubing along the borehole may be increased.
Further, even when using jointed pipes, wells with directional
changes resulting in "doglegs" or a crooked borehole, may restrict
the amount of rotation that may be used. Moreover, when using these
physical methods to reduce friction, friction may continue to build
as the borehole is drilled, and the conduit is inserted deeper.
Thus, eventually enough friction may be present to prevent further
insertion or extraction of a conduit from the borehole. This
effectively means that drilling rigs may sometimes drill longer
horizontal sections than completion equipment can complete.
[0007] Friction reducers have proven effective in reducing the
coefficient of friction between two metal substrates. Some examples
may include the deposition of polymer particles onto a metal
substrate. In these examples, the oil must have a charge
association. However, this approach may be ineffective when there
are not two metal substrates present to provide the deposition
sites, or when fluid conditions, such as the fluid pH, change when
in use, and these changed fluid conditions alter the charge
association and prevent film buildup or transport of the friction
reducers.
[0008] Consequently, there is a need for an organic nonhazardous
biodegradable friction reducer that is not charge specific, does
not require mechanical deposition to reduce the coefficient of
friction, is usable between any types of media, and can function in
any water condition regardless of the pH of the water or the
presence of suspended or dissolved solids.
BRIEF SUMMARY
[0009] These and other needs in the art are addressed in an
embodiment by a method for reducing a coefficient of friction
between two surfaces in a borehole. The method includes preparing a
mixture comprising a primary lubricating agent, a primary
surfactant, a spreading agent, and an aqueous fluid. The method
also includes pumping the mixture into the borehole such that the
mixture contacts the two surfaces and reduces the coefficient of
friction for the two surfaces.
[0010] These and other needs in the art are addressed in other
embodiments by a pumpable friction reducing fluid composition. The
composition includes a primary lubricating agent, a primary
surfactant, a spreading agent, and an aqueous fluid.
[0011] The foregoing has outlined rather broadly the features and
technical advantages of the present invention in order that the
detailed description of the invention that follows may be better
understood. Additional features and advantages of the invention
will be described hereinafter that form the subject of the claims
of the invention. It should be appreciated by those skilled in the
art that the conception and the specific embodiments disclosed may
be readily utilized as a basis for modifying or designing other
embodiments for carrying out the same purposes of the present
invention. It should also be realized by those skilled in the art
that such equivalent embodiments do not depart from the spirit and
scope of the invention as set forth in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] These drawings illustrate certain aspects of some of the
examples of the present method and should not be used to limit or
define the method.
[0013] FIG. 1 is an overall view of a horizontal well configuration
in accordance with present embodiments.
[0014] FIG. 2 is a sectional view of a horizontal portion of the
horizontal well with coiled tubing located within the casing of the
well in accordance with present embodiments.
[0015] FIG. 3 is an overview of the process of linking of a
hydrophobic tail of a lubricating agent with the hydrophobic tail
of another lubricating agent in accordance with present
embodiments.
[0016] FIG. 4 is a perspective view of the friction-testing device
used to test fluids in accordance with present embodiments.
[0017] FIG. 5 is a graph of the results of tests using the test
apparatus of FIG. 4 in accordance with embodiments.
DETAILED DESCRIPTION
[0018] FIG. 1 illustrates a typical coiled tubing drilling
apparatus in a horizontal well 100 having wellhead 10. Support 16
holds a reel of coiled tubing 18, which is guided over curved
support 11 into the well 100. Wellhead 10 may include a blowout
preventer, a snubbing mechanism, or other conventional equipment.
The well 100 is cased with casing 26 that extends within the well
bore 105 through formations 20 in the vertical section 110 of the
well and through formation 28 in the horizontal section 115.
[0019] For certain well completion processes, such as drilling
bridge plugs from casing 26, coiled tubing 18 is lowered into the
well 100 and enters the horizontal section 115 of casing 26, which
is normally cemented in formation 28. Turbine or motor 17 and bit
19 may be attached to the distal end of the coiled tubing 18 to
drill out devices such as bridge plugs (not shown) that have been
inserted into the horizontal section 115 of the casing 26. For
drilling applications, a fluid is pumped through coiled tubing 18,
motor 17 and bit 19 and returns to the wellhead 10 through the
annulus 120 (illustrated in FIG. 2) between coiled tubing 18 and
casing 26.
[0020] As coiled tubing 18 is pushed through the horizontal section
115 of the casing 26, contact may occur at points 31-35, shown in
FIG. 2. Contact at contact points 31-35 may be between any types of
media including any similar or dissimilar media that may be
inserted into the well 100. For example, contact may be
metal-to-metal contact, plastic-to-plastic contact,
metal-to-plastic contact, etc. Friction increases the force
required to place the coiled tubing 18 in the well 100 and may
limit the length of the coiled tubing 18 that may be placed in the
horizontal section 115 of the casing 26.
[0021] In embodiments, a friction reducer may be introduced to the
well 100 to reduce the friction at contact points 31-35. The
friction reducer may be used to reduce the coefficient of friction
between the two similar or dissimilar media which may form contact
points 31-35. In embodiments, the friction reducer comprises a
primary lubricating agent. The primary lubricating agent comprises
a tall oil fatty acid, a tallow oil fatty acid, or a combination
thereof. Tall oil fatty acids as defined herein, are any fatty acid
produced via the Kraft process of wood pulp manufacture. One of
ordinary skill in the art would understand the Kraft process which
generally involves treatment of wood chips with a mixture of sodium
hydroxide and sodium sulfide that breaks the bonds that link lignin
to the cellulose. In some embodiments, the tall oil fatty acid may
have a partially unsaturated C18 backbone. Examples of a tall oil
fatty acid include, but are not limited to palmitic acid,
palmitoleic acid, stearic acid, oleic acid, linoleic acid, or a
combination thereof. Tallow oil fatty acids as defined herein, are
any fatty acid produced from rendering beef or mutton fat. One of
ordinary skill in the art would understand that rendering beef or
mutton fat generally involves a batch or a continuous process in
which an amount of tissue material is heated in a steam-jacketed
vessel to drive off the moisture and simultaneously release the fat
from the fat cells. Examples of a tallow oil fatty acid include,
but are not limited to palmitic acid, palmitoleic acid, stearic
acid, myristic acid, oleic acid, linoleic acid, linolenic acid, or
a combination thereof. The tall oil fatty acid or tallow oil fatty
acid may be used in a crude or refined form. The friction reducer
may also comprise optional additional lubricating agents, for
example, secondary or tertiary lubricating agents. The optional
additional lubricating agents may comprise one of the example
primary lubricating agents discussed above, or may comprise a
lubricating agent that is not a tall oil fatty acid, a tallow oil
fatty acid, or a combination thereof.
[0022] In embodiments, the friction reducer comprises a primary
surfactant. The primary surfactant comprises a nonionic
polyethylene glycol surfactant with a hydrophile/lipophile balance
between 9 to 14 and a molecular weight in a range of about 200 to
about 600. Suitable examples include, but are not limited to
poly(ethylene glycol) monooleate, poly(ethylene glycol) dioleate,
poly(ethylene glycol) monolaurate, poly(ethylene glycol) dilaurate,
or a combination thereof.
[0023] In embodiments, the friction reducer comprises a spreading
agent. The spreading agent comprises a transesterified lipid.
Suitable examples include, but are not limited to methyl canolate,
methyl caprate, methyl caprylate, methyl coconate, methyl lardate,
methyl laurate, methyl myristate, methyl oleate, methyl palm
kernelate, methyl palmitate, methyl soyate, methyl stearate, methyl
tallowate, or a combination thereof. In embodiments, the friction
reducer may comprise the spreading agent in a 4:1 to 1:4 ratio by
weight percent with the primary lubricating agent. For example, the
ratio of the spreading agent to the primary lubricating agent may
be about 4:1 by weight percent, about 3:1 by weight percent, about
2:1 by weight percent, about 1:1 by weight percent, about 1:2 by
weight percent, about 1:3 by weight percent, about 1:4 by weight
percent, and so on. In a specific embodiment, the spreading agent
may be present in the friction reducer in a 1:1 ratio with the
primary lubricating agent.
[0024] In optional embodiments, the friction reducer may comprise a
secondary surfactant. The secondary surfactant comprises a nonionic
alkanolamide family member that is a reaction product of
diethanolamine and a fatty acid. In optional embodiments, the
secondary surfactant has a hydrophile/lipophile balance between 9
to 14 and a molecular weight in a range of about 200 to about 600.
Suitable examples include, but are not limited to cocamide
diethanolamine, lauramide diethanolamine, oleamide diethanolamine,
a soyamide diethanolamine, lauric acid diethanolamine, oleic acid
diethanolamine, or a combination thereof. Where present, the
friction reducer may comprise the secondary surfactant in a 4:1 to
1:4 ratio by weight percent with the primary surfactant. For
example, the ratio of the secondary surfactant to the primary
surfactant may be about 4:1 by weight percent, about 3:1 by weight
percent, about 2:1 by weight percent, about 1:1 by weight percent,
about 1:2 by weight percent, about 1:3 by weight percent, about 1:4
by weight percent, and so on. In a specific embodiment, the
secondary surfactant may be present in the friction reducer in a
1:1 ratio with the primary surfactant.
[0025] In embodiments, the aqueous fluid may be added to the
friction reducer prior to pumping the friction reducer into a
borehole. The aqueous fluid may be from any source. The aqueous
fluid may comprise fresh water or salt water. Salt water generally
may include one or more dissolved salts therein and may be
saturated or unsaturated as desired for a particular application.
Seawater or brines may be suitable for use in some applications.
The aqueous fluid may comprise any amount of dissolved solids
and/or suspended solids. The dissolved solids and/or suspended
solids may be from any source. The aqueous fluid may comprise any
pH, for example, the aqueous fluid may comprise a pH of about 1 to
about 14. Further, the aqueous fluid may be present in an amount
sufficient to form a pumpable fluid. In certain embodiments, the
aqueous fluid may be present in an amount in the range of from
about 33% to about 200% by weight of the friction reducer. In
certain embodiments, the aqueous fluid may be present in an amount
in the range of from about 35% to about 70% by weight of the
friction reducer. With the benefit of this disclosure one of
ordinary skill in the art should recognize the appropriate amount
of aqueous fluid for a chosen application.
[0026] The components of the friction reducer may be added to the
aqueous fluid in any order. Further, two or more of the components
of the friction reducer may be mixed before adding the aqueous
fluid. The components of the friction reducer may be mixed in any
order, for example the primary lubricating agent may be mixed with
the primary surfactant. The spreading agent may then be added to
and mixed with this mixture. The aqueous fluid may then be added to
that mixture of the primary lubricating agent, primary surfactant,
and the spreading agent to form an unstable oil-in-water emulsion.
As an alternative example, the primary surfactant may be added to
the aqueous fluid and mixed. To this mixture, the primary
lubricating agent and the spreading agent may be added and mixed to
form an unstable oil-in-water emulsion where the primary
lubricating agent comprises the dispersed phase, and the aqueous
fluid comprises the continuous phase. Without limitation by theory,
it is believed that not fully emulsifying the primary lubricating
agent may be important for achieving deposition of the micelles
formed from the primary lubricating agent on a surface to be
lubricated, as discussed in more detail below.
[0027] Without limitation by theory, it is believed that the
nonionic nature of the surfactants allows the friction reducer to
be used in a wide range of aqueous fluid conditions including fresh
water sources such as municipal water supplies to rivers or lakes
or heavily weighted brine and water containing high levels of total
dissolved solids and/or total suspended solids. Moreover, it is
believed that the hydrophile/lipophile balance of 9 to 14 allows
for the formation of suspended microscopic micelles of the primary
lubricating agent. In effect, the primary lubricating agent is
evenly dispersed throughout the aqueous fluid in the friction
reducer, without being fully emulsified. The even dispersal of the
primary lubricating agent also allows for an even deposition of the
primary lubricating agent within the casing 26, formations 20 and
28, coiled tubing 18, or any other surface in which the friction
reducer contacts. The spreading agent may be used to increase
micelle mobility throughout the aqueous fluid. The micelles
comprise polar hydrophilic heads and long hydrophobic tails. The
balance of the hydrophilic heads to the hydrophobic tails is
precisely governed by the hydrophile/lipophile balance of the
primary surfactant and, if present, the secondary surfactant. As
explained below, a hydrophobic tail of the primary lubricating
agent contained within a micelle may be linked or branched to a
hydrophobic tail of another primary lubricating agent as well as
the hydrophobic tails of the primary surfactant and, if present,
the secondary surfactant.
[0028] The nonionic characteristics of the primary and secondary
surfactants allow the friction reducer to be used in a wide range
of aqueous fluid types, including those with high levels of
dissolved solids and/or high levels of suspended solids, with no
perceptible negative effect on performance. In some examples, the
measured coefficient of friction values have been shown to improve
when used in an aqueous fluid comprising elevated levels of
dissolved solids. As mentioned above, certain types of dissolved
solids may allow for the crosslinking of the COOH group of the
hydrophobic tail with divalent (e.g., Ca2+, Mg2+, Cu2+, Fe2+, Mn2+,
etc.) and trivalent (A13+, Fe3+, Mn3+, B3+, etc.) cations present
within the aqueous fluid. FIG. 3 illustrates the linking of the
hydrophobic tail 37 of a molecule of a primary lubricating agent 38
with the hydrophobic tail 37 of another molecule of a primary
lubricating agent 38. Upon introduction into the aqueous fluid, the
hydrophilic head 39 of the molecule of primary lubricating agent 38
dissociates and loses a hydrogen, leaving a corresponding COO--
group. Free divalent and trivalent cations may then act as a bridge
linking the COO-- groups from other molecules of primary
lubricating agent 38 and also any compatible primary and,
optionally, secondary surfactants with COO-- (or other anionic)
groups present. Molecule 40 is an example of two molecules of
primary lubricating agent 38 linked by a divalent cation. Molecule
41 is an example of three molecules of primary lubricating agent 38
linked by a trivalent cation. This process may increase the amount
of hydrophobic tails per molecule of primary lubricating agent 38,
which may in turn provide a stronger and more robust lubricating
boundary layer between any similar or dissimilar media. It is to be
understood that the more impurities that are present the stronger
and more ridged the micelles can become due to the linking of the
hydrophobic tails of the primary lubricating agent. Without the use
of nonionic surfactants with the properties disclosed herein,
organized micelle formation may not occur, and hydrophobic tail
linking may not occur.
[0029] The cohesive force that promotes deposition of the micelles
on a media's surface is due to the inherent nature of the
hydrophobic tales migrating to and attaching to any available
surface within the aqueous fluid body. The hydrophobic tales may
then orientate themselves and attach at an angle (e.g., a
90.degree. angle) relative to the surface, with the subsequent
deformation of the spherical shape of the micelle, such that the
micelle may break apart as the hydrophobic tales attach to the
surface, leaving the hydrophilic heads facing the aqueous fluid
body. The deposited micelles create an extremely tenacious boundary
layer between any of the surfaces they contact, and this boundary
layer may significantly lower the coefficient of friction between
two surfaces. Ultimately, this composition may allow an operator to
convey a work string (e.g., coiled tubing 18 as shown in FIGS. 1
and 2) within the borehole with much less required energy. This may
in turn lessen the chance of sticking and greatly improve the
overall efficiency of a drilling operation.
[0030] This organic mixture has proven to be much more effective
than conventional chemistry in horizontal oil and gas well drilling
and completion operations. Tests have been performed on an oil and
gas well, and the rotational torque and weight of the pipe were
compared to conventional chemistry. The mixture showed a twofold
improvement in friction with one third of the volumetric dosage
rates. This improved performance at lower dosage rates is
substantial in reducing the overall carbon footprint associated
with the manufacturing, transportation, storage and application of
these chemicals. It should also be noted that during these tests,
water that had been produced from an oil and gas well and
containing high levels of suspended and dissolved solids, that
would have normally been injection into disposal wells was used as
the aqueous solution in which the mixture was applied into. This
mixture has proven effective not only in very turbid fluid
conditions but within a wide range of PH conditions.
[0031] The media lubricated by the friction reducer may be any such
media as desired, including similar (i.e. the same types of media)
or dissimilar (i.e. different types of media). Without limitation,
the media may comprise metal (e.g., iron, steel, copper, aluminum,
etc.); plastic (polypropylene, polyethylene, polyvinyl chloride,
etc.); any and all types of rock (e.g., shale) which may occur in a
formation (e.g., formations 20 and 28 as illustrated on FIG. 1);
wood; composites thereof; or combinations thereof. In embodiments,
the friction reducer may be used to lower the coefficient of
friction of the two media. Without limitation by theory, this is
believed to occur, because the friction reducer may form a boundary
layer between the surfaces of the two media, such that the amount
of contact between the surfaces of the two media is reduced. For
example, the friction reducer may be used to lower the coefficient
of friction between a metal and a rock. As another example, the
friction reducer may be used to reduce the coefficient of friction
between a plastic and a metal.
[0032] In embodiments, the friction reducer may be non-toxic at the
concentrations used in the disclosed examples. Non-toxic is defined
herein as a product that does not produce immediate personal injury
or illness to humans when it is inhaled, swallowed, or absorbed
through the skin. As such, the friction reducer may be prepared for
use with a reduced risk to personnel as compared to the use of
toxic friction reducing compositions. The friction reducer may be
biodegradable at the concentrations used in the disclosed examples.
Biodegradable is defined herein as any material which is capable of
degradation by a microorganism or through any other biological
means. The friction reducer may biodegrade at varying rates
dependent upon the species of lubricating agent, surfactant, and
spreading agent chosen, as well as the conditions present to induce
biodegradation. Thus, the friction reducer may be placed and/or
disposed on the surface or within a borehole, with a reduced risk
of forming a permanent deposit of the friction reducer on the
surface, on equipment, or otherwise within the borehole. The
friction reducer may be biocompatible at the concentrations used in
the disclosed examples. Biocompatible is defined herein as the
ability to be in contact with a living system (e.g, plants,
animals, etc.) without producing an adverse effect. The friction
reducer may contact living systems without risk of damaging those
systems and may therefore be used in operations and/or at
concentrations in which other friction reducers may not be used.
For example, the friction reducer may be used in operations where
the risk of and the potential damage caused by pollution may be
elevated.
EXAMPLES
[0033] To facilitate a better understanding of the present claims,
the following examples of certain aspects of the disclosure are
given. In no way should the following examples be read to limit, or
define, the entire scope of the claims.
Example 1
[0034] An illustration of a device used to evaluate the performance
of the friction reducer disclosed herein is shown in FIG. 4. This
bench-top friction tester is manufactured by JUSTICE BROS..RTM.,
and is intended for evaluating the performance of lube oil
additives. JUSTICE BROS..RTM. is a registered trademark of Justice
Brothers, Inc. of Duarte, Calif. Force F of a metal bar is applied
to rotating metal bearing surface 51. Cup 52 surrounding the bottom
quarter of the rotating bearing surface provides a reservoir to
hold the fluid being tested. Force F is applied to lever 53 by
placing weight 54 on one end of the lever. A 1-pound weight applies
a force of 100 psi to the bearing surface. The performance of the
fluids is measured by observing the amperage draw of 110 volt
one-quarter HP motor 55 used to rotate the bearing with a constant
force on the bearing. Amperage is recorded in 5-second intervals.
The testing is complete when galling of the bearing surface is
heard or current drawn by the motor reaches 10 amps.
[0035] A 200 gram sample was prepared by mixing a 0.5% solution of
the composition given in Table 1 into distilled water and mixing in
a 200 mL beaker with magnetic stirring for 3 minutes.
TABLE-US-00001 TABLE 1 Component Amount by weight Hydrocarbon oil
91.2% Ethylene bis-amide 5% Polyethylene Glycol 600 dioleate
tallate 2% TEFLON .RTM. Particles 1.8%
[0036] The sample was then quickly poured into cup 52 (FIG. 4).
While holding the weight off the static bearing surface, the unit
was turned on to allow the solution to coat the bearing surface.
After a brief time, arm 53 was lowered to apply a force of 200
pounds on the bearing surfaces, and the timer was started. After
completion of a test, the cup was removed from the tester and
cleaned with isopropyl alcohol. The bearing surfaces were removed
and replaced with new ones. Tests were performed with the mixture
of Example 1 and with other fluids.
[0037] FIG. 5 is a graph showing the amperage drawn by the motor
over a period of time with different fluids in the test apparatus
illustrated in FIG. 4. Lines A, C, and D, represent results for
products presently used for completions in the oil and gas
industry. In a non-limiting example, the products presently used
for completions represented by lines A, C, and D may include, FRAQ
SLIQ 1911 and FRAQ SLIQ 3006 produced by Rockwater Energy
Solutions, ForceGlide produced by Force Chem Technologies, Slick
Frog FR and Salty Frog FR produced by Greenwell Energy Solutions,
and HE.RTM. 150 Polymer and LIQUID HE.RTM. 150 Polymer produced by
Chevron Phillips Chemical Company and the like. HE.RTM. is a
registered trademark of Chevron Phillips Chemical Company LP. Line
B represents results for a mixture of TEFLON.RTM. and water.
TEFLON.RTM. is a registered trademark of the Chemours Company FC,
LLC of Wilmington, Del. Line E represents results for the
composition of Example 1.
[0038] The graph clearly indicates that products A-D resulted in an
amperage draw approaching 10 in a much shorter time period than
that of the composition disclosed above and in Example 1.
Compositions A-D led to currents approaching 10 amps in 20-30
seconds, whereas the formulation disclosed here led to currents
approaching 10 amps after 70 seconds.
Example 2
[0039] A well operator had set 10 bridge plugs inside casing in the
horizontal section of a well in Texas. Operations to drill the
bridge plugs were conducted using coiled tubing. The well had a
vertical depth of about 8,290 ft and had a measured depth of about
13,220 ft. Coiled tubing had been used to drill all plugs but the
bottom two plugs. Using a conventional friction reducing fluid,
friction limited the ability to drill the last two plugs. The
decision was made to try the oil phase composition disclosed
herein. After adding the oil phase mixture disclosed in Example 1
to water at rates of 1 or 2 gals per 10 bbls and circulating the
present fluid up the annulus outside the coiled tubing, the final
two plugs were reached and drilled. In a second well drilled from
the same pad as the first well, friction was higher than in the
first, but all the plugs were successfully drilled from the well
using the composition disclosed herein. The representative of the
well operator who was present during the drilling operations
commented that he did not believe all the plugs could have been
drilled without the use of the materials disclosed herein.
[0040] The concentrations given in Example 1 may be varied over a
broad range. The concentration of TEFLON.RTM. particles may range
from about 1% by weight to about 8% by weight. The concentration of
ethylene bis-amide may vary from about 1% to about 10%. Tests can
be used to determine an effective amount of suspending agent. The
concentration of surfactant may range from about 1% to about 5%.
Tests such as described above can be used to determine an effective
amount of surfactant.
[0041] The formulation of the present invention has also been found
to inhibit corrosion on metal surfaces. Pieces of 1/4-in plate were
cut into 2-in.times.5-in strips and their surface ground to bare
metal. Two were used as a control and not coated with anything. One
strip was sprayed with a 10 lb/gal brine and one was not. Both were
set outside in atmospheric conditions. Two of the strips were
treated with a solution of polyacrylamide in water, which is the
composition of fluids used in many completion, workover and
fracturing operations. One of these was sprayed with a 10 lb/gal
brine and one was not. Both were set outside in atmospheric
conditions. The other two strips were treated with oil containing
the surfactant TEFLON.RTM. as disclosed herein. One was then
sprayed with brine and one was not. Both were put outside in
atmospheric conditions. After five days in atmospheric conditions,
the strips treated with the oil containing surfactant and
TEFLON.RTM. disclosed herein showed corrosion (rust) on less than
15% of the surface, while the other samples had rust on 100% of the
surface area. The samples treated with the polyacrylamide fluid
showed no better corrosion resistance than the control plates that
had no treatment. Surface rust for the control plate treated with
the 10 lb/gal brine was noticeably thicker than the one that was
not sprayed. This held true for both the control plate and the one
treated with polyacrylamide. The surface area for both the control
plates and those treated with polyacrylamide had rust on 100% of
the surface area.
[0042] The corrosion tests show that the fluid disclosed herein
provides corrosion protection to steel surfaces in a well after
contact with the fluid. This means that the oil, surfactant
friction reducer containing TEFLON.RTM. can be pumped on an
intermittent basis to provide corrosion protection and friction
reduction on the surfaces of tubulars in a well.
[0043] The preceding description provides various embodiments which
may contain alternative combinations of components. It should be
understood that, although individual embodiments may be discussed
herein, the present disclosure covers all combinations of the
disclosed embodiments, including, without limitation, the different
component combinations, and properties of the system. It should be
understood that the compositions are described in terms of
"comprising," "containing," or "including" various components or
steps, the compositions can also "consist essentially of" or
"consist of" the various components and steps. Moreover, the
indefinite articles "a" or "an," as used in the claims, are defined
herein to mean one or more than one of the element that it
introduces.
[0044] For the sake of brevity, only certain ranges are explicitly
disclosed herein. However, ranges from any lower limit may be
combined with any upper limit to recite a range not explicitly
recited, as well as, ranges from any lower limit may be combined
with any other lower limit to recite a range not explicitly
recited, in the same way, ranges from any upper limit may be
combined with any other upper limit to recite a range not
explicitly recited. Additionally, whenever a numerical range with a
lower limit and an upper limit is disclosed, any number and any
included range falling within the range are specifically disclosed.
In particular, every range of values (of the form, "from about a to
about b," or, equivalently, "from approximately a to b," or,
equivalently, "from approximately a-b") disclosed herein is to be
understood to set forth every number and range encompassed within
the broader range of values even if not explicitly recited. Thus,
every point or individual value may serve as its own lower or upper
limit combined with any other point or individual value or any
other lower or upper limit, to recite a range not explicitly
recited.
[0045] Therefore, the present embodiments are well adapted to
attain the ends and advantages mentioned as well as those that are
inherent therein. The particular embodiments disclosed above are
illustrative only, and may be modified and practiced in different
but equivalent manners apparent to those skilled in the art having
the benefit of the teachings herein. Although individual
embodiments are discussed, the disclosure covers all combinations
of all of the embodiments. Furthermore, no limitations are intended
to the details of construction or design herein shown, other than
as described in the claims below. Also, the terms in the claims
have their plain, ordinary meaning unless otherwise explicitly and
clearly defined by the patentee. It is therefore evident that the
particular illustrative embodiments disclosed above may be altered
or modified and all such variations are considered within the scope
and spirit of those embodiments. If there is any conflict in the
usages of a word or term in this specification and one or more
patent(s) or other documents that may be incorporated herein by
reference, the definitions that are consistent with this
specification should be adopted.
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