U.S. patent application number 13/849309 was filed with the patent office on 2014-05-15 for settable compositions comprising wollastonite and pumice and methods of use.
This patent application is currently assigned to Halliburton Energy Services, Inc.. The applicant listed for this patent is HALLIBURTON ENERGY SERVICES, INC.. Invention is credited to D. Chad Brenneis, Jiten Chatterji, Crystal L. Keys.
Application Number | 20140130716 13/849309 |
Document ID | / |
Family ID | 49321426 |
Filed Date | 2014-05-15 |
United States Patent
Application |
20140130716 |
Kind Code |
A1 |
Chatterji; Jiten ; et
al. |
May 15, 2014 |
Settable Compositions Comprising Wollastonite and Pumice and
Methods of Use
Abstract
Methods and compositions are provided that relate to cementing
operations, including a method of cementing that may comprise
providing a settable composition that may comprise wollastonite,
pumice, a calcium-ion source, and water, wherein the wollastonite
may be present in an amount in a range of from about 25% to about
75% by combined weight of the wollastonite and pumice, and wherein
the pumice may present in an amount in a range of from about 25% to
about 75% by combined weight of the wollastonite and pumice.
Embodiments of the method further may comprise allowing the
settable composition to set.
Inventors: |
Chatterji; Jiten; (Duncan,
OK) ; Brenneis; D. Chad; (Marlow, OK) ; Keys;
Crystal L.; (Indiahoma, OK) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HALLIBURTON ENERGY SERVICES, INC. |
Houston |
TX |
US |
|
|
Assignee: |
Halliburton Energy Services,
Inc.
Houston
TX
|
Family ID: |
49321426 |
Appl. No.: |
13/849309 |
Filed: |
March 22, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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13672837 |
Nov 9, 2012 |
8557036 |
|
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13849309 |
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Current U.S.
Class: |
106/698 ;
106/710; 106/792; 106/793; 106/796; 106/799; 524/433 |
Current CPC
Class: |
C04B 40/0039 20130101;
C09K 8/467 20130101; C04B 28/12 20130101; Y02W 30/92 20150501; C04B
2111/1037 20130101; Y02W 30/91 20150501; C09K 8/428 20130101; C04B
28/10 20130101; C04B 40/0028 20130101; C04B 2111/00068 20130101;
C04B 7/34 20130101; C04B 2111/00146 20130101; C04B 28/02 20130101;
Y02W 30/95 20150501; Y02W 30/94 20150501; C04B 40/0042 20130101;
C04B 28/02 20130101; C04B 14/043 20130101; C04B 14/16 20130101;
C04B 14/185 20130101; C04B 22/062 20130101; C04B 2103/22 20130101;
C04B 2103/408 20130101; C04B 2103/46 20130101; C04B 28/12 20130101;
C04B 14/043 20130101; C04B 14/10 20130101; C04B 14/108 20130101;
C04B 14/16 20130101; C04B 14/18 20130101; C04B 18/08 20130101; C04B
18/101 20130101; C04B 18/146 20130101; C04B 18/162 20130101; C04B
20/002 20130101; C04B 20/0048 20130101; C04B 38/02 20130101; C04B
38/10 20130101; C04B 2103/0088 20130101; C04B 2103/12 20130101;
C04B 2103/22 20130101; C04B 2103/408 20130101; C04B 2103/44
20130101; C04B 2103/46 20130101; C04B 2103/50 20130101 |
Class at
Publication: |
106/698 ;
106/792; 106/796; 106/793; 106/710; 106/799; 524/433 |
International
Class: |
C04B 7/34 20060101
C04B007/34 |
Claims
1. A settable composition comprising: wollastonite; pumice; a
calcium-ion source in an amount in a range of from about 0.1% to
about 25% by combined weight of the wollastonite and pumice; and
water in an amount sufficient to form a pumpable slurry and present
in a range of from about 40% to about 200% by combined weight of
the wollastonite and pumice; wherein the wollastonite is present in
an amount in a range of from about 25% to about 75% by combined
weight of the wollastonite and pumice; and wherein the pumice is
present in an amount in a range of from about 25% to about 75% by
combined weight of the wollastonite and pumice, and wherein the
settable composition is free of an additional cementitious
components or comprises the additional cementitious components in
an amount of about 1% or less by combined weight of the
wollastonite and pumice.
2. The composition of claim 1, wherein the settable composition has
a density in a range of from about 12 pounds per gallon to about 20
pounds per gallon.
3. The composition of claim 1, wherein the water is present in an
amount in a range of from about 40% to about 150% by combined
weight of the wollastonite and pumice.
4. The composition of claim 1, wherein the calcium-ion source
comprises lime.
5. The composition of claim 1, wherein the calcium-ion source is
present in an amount in a range of from about 1% to about 10% by
combined weight of the wollastonite and pumice.
6. The composition of claim 1, wherein the settable composition
further comprises an additive selected from the group consisting of
a dispersant, a strength-retrogression additive, a set accelerator,
a set retarder, a weighting agent, a lightweight additive, a
gas-generating additive, a mechanical property enhancing additive,
a lost-circulation material, a filtration-control additive, a fluid
loss control additive, a foaming additive, a defoaming additive, a
thixotropic additive, and any combination thereof.
7. The composition of claim 1, wherein the settable composition
further comprises an additive selected from the group consisting of
crystalline silica, amorphous silica, fumed silica, salts, fibers,
hydratable clays, calcined shale, vitrified shale, microspheres,
fly ash, diatomaceous earth, metakaolin, ground perlite, rice husk
ash, natural pozzolan, zeolite, cement kiln dust, resins, any
combination thereof.
8. (canceled)
9. The composition of claim 1, wherein the settable composition is
free of Portland cement.
10. The composition of claim 1, wherein the wollastonite has a mean
particle size of about 1 micron to about 200 microns.
11. The composition of claim 1, wherein the pumice has a mean
particle size of about 1 micron to about 50 microns.
12. A settable composition comprising: a cementitious component,
wherein the cementitious comprises wollastonite and pumice; lime;
and water; wherein the settable composition is free of any
additional cementitious components or comprises the additional
cementitious components in an amount less than about 1% or less by
weight of the cementitious component.
13. The composition of claim 12, wherein the lime is present in the
settable composition in an amount in a range of from about 0.1% to
about 25% by combined weight of the wollastonite and pumice.
14. The composition of claim 12, wherein the settable composition
has a density in a range of from about 12 pounds per gallon to
about 20 pounds per gallon.
15. The composition of claim 12, wherein the settable composition
further comprises an additive selected from the group consisting of
a dispersant, a strength-retrogression additive, a set accelerator,
a set retarder, a weighting agent, a lightweight additive, a
gas-generating additive, a mechanical property enhancing additive,
a lost-circulation material, a filtration-control additive, a fluid
loss control additive, a foaming additive, a defoaming additive, a
thixotropic additive, and any combination thereof.
16. The composition of claim 12, wherein the settable composition
further comprises an additive selected from the group consisting of
crystalline silica, amorphous silica, fumed silica, salts, fibers,
hydratable clays, calcined shale, vitrified shale, microspheres,
fly ash, diatomaceous earth, metakaolin, ground perlite, rice husk
ash, natural pozzolan, zeolite, cement kiln dust, resins, any
combination thereof.
17. The composition of claim 12, wherein the water is present in an
amount in a range of from about 40% to about 200% by combined
weight of the wollastonite and pumice.
18. The composition of claim 12, wherein the wollastonite is
present in an amount in a range of from about 25% to about 75% by
combined weight of the wollastonite and pumice;
19. The composition of claim 12, wherein the wollastonite has a
mean particle size of about 1 micron to about 200 microns.
20. The composition of claim 12, wherein the pumice has a mean
particle size of about 1 micron to about 50 microns.
21. The composition of claim 1, wherein the calcium-ion source is
calcium oxide, calcium hydroxide, or a combination thereof.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a divisional application of U.S.
patent application Ser. No. 13/672,837 entitled "Settable
Compositions Comprising Wollastonite and Pumice and Methods of
Use," filed on Nov. 9, 2012, the entire disclosure of which is
incorporated herein by reference.
BACKGROUND
[0002] The present invention relates to cementing operations and,
more particularly, in certain embodiments, to settable compositions
comprising wollastonite and pumice and associated methods of use in
cementing operations.
[0003] In cementing operations, such as well construction and
remedial cementing, settable compositions are commonly utilized. As
used herein, the term "settable composition" refers to a
composition that hydraulically sets or otherwise develops
compressive strength. Settable compositions may be used in primary
cementing operations whereby pipe strings, such as casing and
liners, are cemented in well bores. In a typical primary cementing
operation, a settable composition may be pumped into an annulus
between the walls of the well bore and the exterior surface of the
pipe string disposed therein or between the pipe string and a
larger conduit in the subterranean formation. The settable
composition may set in the annular space, thereby forming an
annular sheath of hardened, substantially impermeable material
(e.g., a cement sheath) that may support and position the pipe
string in the well bore and may bond the exterior surface of the
pipe string to the well bore walls or to larger conduit. Among
other things, the cement sheath surrounding the pipe string should
function to prevent the migration of fluids in the annulus, as well
as protecting the pipe string from corrosion. Settable compositions
also may be used in remedial cementing methods, such as in the
placement of plugs and in squeeze cementing for sealing voids in a
pipe string, cement sheath, gravel pack, subterranean formation,
and the like.
[0004] A particular challenge in cementing operations is the
development of satisfactory mechanical properties in a settable
composition within a reasonable time period after placement in the
subterranean formation. During the life of a well, the subterranean
cement sheath undergoes numerous strains and stresses as a result
of temperature effects, pressure effects, and impact effects. The
ability to withstand these strains and stresses is directly related
to the mechanical properties of the settable composition after
setting. The mechanical properties are often characterized using
parameters such as compressive strength, tensile strength, Young's
Modulus, Poisson's Ratio, elasticity, and the like. These
properties may be modified by the inclusion of additives.
[0005] One type of settable composition that has been used
comprises Portland cement as the cementitious component. Portland
cement is one of the more common cementitious components used
throughout the world and is usually produced by a process that
comprises sintering a mixture of a predetermined composition and
then grinding the resulting Portland cement clinker. While Portland
cement has been used in well construction and remedial cementing
for a number of years, drawbacks to Portland cement include the
energy requirements to produce Portland cement. These energy
requirements greatly increase the cost of creating Portland cement.
Efforts to reduce the cost of settable compositions have come in
the form of replacing Portland cement with other solid particulate
components.
SUMMARY
[0006] An embodiment discloses a method of cementing. Embodiments
of the method may comprise providing a settable composition that
may comprise wollastonite, pumice, a calcium-ion source, and water,
wherein the wollastonite may be present in an amount in a range of
from about 25% to about 75% by combined weight of the wollastonite
and pumice, and wherein the pumice may present in an amount in a
range of from about 25% to about 75% by combined weight of the
wollastonite and pumice. Embodiments of the method further may
comprise allowing the settable composition to set.
[0007] Another embodiment discloses a method of cementing.
Embodiments of the method may comprise preparing a base fluid that
may comprise water and lime. Embodiments of the method further may
comprise preparing a dry blend that may comprise wollastonite and
pumice, wherein the wollastonite may be present in an amount in a
range of from about 25% to about 75% by combined weight of the
wollastonite and pumice, wherein the pumice may be present in an
amount in a range of from about 25% to about 75% by combined weight
of the wollastonite and pumice. Embodiments of the method further
may comprise combining the base fluid and the dry blend to form a
settable composition that is essentially free of Portland cement.
Embodiments of the method further may comprise introducing the
settable composition into a subterranean formation. Embodiments of
the method further may comprise allowing the composition to set in
the subterranean formation.
[0008] Another embodiment discloses a settable composition that may
comprise wollastonite, pumice, a calcium-ion source, water, wherein
the wollastonite may be present in an amount in a range of from
about 25% to about 75% combined weight of the wollastonite and
pumice, and wherein the pumice may be present in an amount in a
range of from about 25% to about 75% by combined weight of the
wollastonite and pumice.
[0009] The features and advantages of the present invention will be
readily apparent to those skilled in the art. While numerous
changes may be made by those skilled in the art, such changes are
within the spirit of the invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0010] Embodiments of the present invention disclose settable
compositions comprising wollastonite, pumice, a calcium-ion source,
and water. One of the many potential advantages of embodiments of
the settable compositions is that use of wollastonite and pumice
may provide the settable compositions with adequate compressive
strengths for use in subterranean applications without the need of
Portland cement. By way of example, the compressive strength of the
settable compositions containing wollastonite and pumice may be
equal to or greater than a settable composition in which the
wollastonite and pumice has been replaced with Portland cement.
Accordingly, embodiments of the settable compositions may be used
in a variety of subterranean applications where settable
compositions may be used, including, but not limited to, primary
and remedial cementing.
[0011] In some embodiments, the settable compositions may comprise
wollastonite. Wollastonite is generally a calcium inosilicate
mineral used in industrial applications, such as ceramics, friction
products, metal making, paint filler, and plastics. Wollastonite
may be mined in a number of different locations throughout the
world and then processed for use in industrial applications.
Wollastonite may be considered a cementitious component as it sets
and hardens in the presence of silica, lime and water. Wollastonite
used in embodiments of the present invention may have a mean
particle size in a range of from about 1 microns to about 200
microns, and, alternatively, from about 5 microns to about 100
microns. The wollastonite may be included in embodiments of the
settable compositions in an amount suitable for a particular
application. In some embodiments, the wollastonite may be present
in the settable compositions in an amount in a range of from about
25% to about 75% by combined weight of the wollastonite and pumice.
In particular embodiments, the wollastonite may be present in an
amount ranging between any of and/or including any of about 25%,
about 30%, about 40%, about 50%, about 60%, about 70%, or about 75%
by combined weight of the wollastonite and pumice. One of ordinary
skill, with the benefit of this disclosure, should recognize the
amount of the wollastonite to include for a chosen application.
[0012] In some embodiments, the settable compositions may comprise
pumice. Generally, pumice is a volcanic rock that exhibits
cementitious properties, in that it may set and harden in the
presence of lime and water. Pumice may be mined in a number of
different locations throughout the world and then processed for use
in industrial applications. Pumice used in embodiments of the
present invention may have a mean particle size in a range of from
about 1 microns to about 50 microns, and, alternatively, from about
1 microns to about 20 microns. An example of a suitable pumice is
available from Hess Pumice Products, Inc., Malad City, Id., under
the trade name DS-200 having an average particle size of less than
20 microns. The pumice may be included in embodiments of the
settable compositions in an amount suitable for a particular
application. In some embodiments, the pumice may be present the
settable compositions in an amount in the range of from about 25%
to about 75% by combined weight of the wollastonite and pumice. In
some embodiments, the pumice may be present in an amount ranging
between any of and/or including any of about 25%, about 30%, about
40%, about 50%, about 60%, about 70%, or about 75% by combined
weight of the wollastonite and pumice. One of ordinary skill in the
art, with the benefit of this disclosure, should recognize the
appropriate amount of the pumice to include for a chosen
application.
[0013] In some embodiments, the settable compositions may comprise
a calcium-ion source. The calcium-ion source may be included in the
settable compositions for providing calcium ions for reaction with
the wollastonite and/or pumice, for example. One example of a
suitable calcium-ion source comprises lime. As used herein, the
term "lime" is intended to include calcium oxide, calcium
hydroxide, or a combination thereof. In some embodiments, the
calcium-ion source may be present in the settable compositions in
an amount in the range of about 0.1% to about 15% by combined
weight of the wollastonite and pumice. In further embodiments, the
calcium-ion source may be included in an amount in the range of
from about 1% to about 10% by combined weight of the wollastonite
and pumice.
[0014] In some embodiments, the settable compositions may further
comprise hydraulic cement. A variety of hydraulic cements may be
utilized in accordance with the present invention, including, but
not limited to, those comprising calcium, aluminum, silicon,
oxygen, iron, and/or sulfur, which set and harden by reaction with
water. Suitable hydraulic cements include, but are not limited to,
Portland cements, pozzolanic cements, gypsum cements, high alumina
content cements, silica cements, and any combination thereof. In
certain embodiments, the hydraulic cement may comprise a Portland
cement. Portland cements that may be suited for use in example
embodiments may be classified as Class A, C, H and G cements
according to American Petroleum Institute, API Specification for
Materials and Testing for Well Cements, API Specification 10, Fifth
Ed., Jul. 1, 1990. In addition, in some embodiments, hydraulic
cements suitable for use in the present invention may be classified
as ASTM Type I, II, or III.
[0015] Where present, the hydraulic cement generally may be
included in the settable compositions in an amount sufficient to
provide the desired compressive strength, density, and/or cost. In
some embodiments, the hydraulic cement may be present the settable
compositions in an amount in the range of from about 0.1% to about
50% by combined weight of the wollastonite and pumice. For example,
the hydraulic cement may be present in an amount ranging between
any of and/or including any of about 0.1%, about 1%, about 5%,
about 10%, about 20%, about 30%, about 40%, or about 50% by
combined weight of the wollastonite and pumice. In some
embodiments, the hydraulic cement may be included in an amount that
does not exceed about 1%, does not exceed about 5% bwoc, does not
exceed about 10%, does not exceed about 20%, does not exceed about
30%, does not exceed about 40%, or does not exceed about 50% by
combined weight of the wollastonite and pumice.
[0016] In some embodiments, the settable compositions may be
essentially free of any additional cementitious components, such as
the hydraulic cement described herein (e.g., contains less than
about 1% by combined weight of the wollastonite and pumice). In
particular embodiments, the settable compositions may be
essentially free of, or even free of, Portland cement. In some
embodiments, the settable compositions may comprise additional
cementitious components, such as the hydraulic cement, in an amount
less than about 1% by combined weight of the wollastonite and
pumice and, alternatively, less than about 0.1% by combined weight
of the wollastonite and pumice.
[0017] In some embodiments, the settable compositions may further
comprise a dispersant. Where present, the dispersant should act,
among other things, to control the rheology of the settable
composition. While a variety of dispersants known to those skilled
in the art may be used in accordance with the present invention,
examples of suitable dispersants include naphthalene sulfonic acid
condensate with formaldehyde; acetone, formaldehyde, and sulfite
condensate; melamine sulfonate condensed with formaldehyde; any
combination thereof. Where used, the dispersant should be present
in embodiments of the settable compositions in an amount sufficient
to prevent gelation of the settable composition and/or improve
rheological properties. In some embodiments, the dispersant may be
present in the settable compositions in an amount in the range of
from about 0.1% to about 5% by combined weight of the wollastonite
and pumice.
[0018] The water used in embodiments of the settable compositions
of the present invention may include, for example, freshwater,
saltwater (e.g., water containing one or more salts dissolved
therein), brine (e.g., saturated saltwater produced from
subterranean formations), seawater, or any combination thereof.
Generally, the water may be from any source, provided, for example,
that it does not contain an excess of compounds that may
undesirably affect other components in the settable composition. In
some embodiments, the water may be included in an amount sufficient
to form a pumpable slurry. In some embodiments, the water may be
included in the settable compositions in an amount in a range of
from about 40% to about 200% by combined weight of the wollastonite
and pumice. In some embodiments, the water may be included in an
amount in a range of from about 40% to about 150% by combined
weight of the wollastonite and pumice.
[0019] Other additives suitable for use in subterranean cementing
operations may also be added to embodiments of the settable
compositions, in accordance with embodiments of the present
invention. Examples of such additives include, but are not limited
to, strength-retrogression additives, set accelerators, set
retarders, weighting agents, lightweight additives, gas-generating
additives, mechanical property enhancing additives,
lost-circulation materials, fluid-loss-control additives, foaming
additives, thixotropic additives, and any combination thereof.
Specific examples of these, and other, additives include
crystalline silica, amorphous silica, fumed silica, salts, fibers,
hydratable clays, calcined shale, vitrified shale, microspheres,
fly ash, diatomaceous earth, metakaolin, ground perlite, rice husk
ash, natural pozzolan, zeolite, cement kiln dust, resins, any
combination thereof, and the like. A person having ordinary skill
in the art, with the benefit of this disclosure, will readily be
able to determine the type and amount of additive useful for a
particular application and desired result.
[0020] Strength-retrogression additives may be included in
embodiments of the settable composition to, for example, prevent
the retrogression of strength after the settable composition has
been allowed to develop compressive strength when the settable
composition is exposed to high temperatures. These additives may
allow the settable compositions to form as intended, preventing
cracks and premature failure of the cementitious composition.
Examples of suitable strength-retrogression additives may include,
but are not limited to, amorphous silica, coarse grain crystalline
silica, fine grain crystalline silica, or a combination
thereof.
[0021] Set accelerators may be included in embodiments of the
settable compositions to, for example, increase the rate of setting
reactions. Control of setting time may allow for the ability to
adjust to well bore conditions or customize set times for
individual jobs. Examples of suitable set accelerators may include,
but are not limited to, aluminum sulfate, alums, calcium chloride,
calcium sulfate, gypsum-hemihydrate, sodium aluminate, sodium
carbonate, sodium chloride, sodium silicate, sodium sulfate, ferric
chloride, or a combination thereof.
[0022] Set retarders may be included in embodiments of the settable
compositions to, for example, increase the thickening time of the
settable compositions. Examples of suitable set retarders include,
but are not limited to, ammonium, alkali metals, alkaline earth
metals, borax, metal salts of calcium lignosulfonate, carboxymethyl
hydroxyethyl cellulose, sulfoalkylated lignins, hydroxycarboxy
acids, copolymers of 2-acrylamido-2-methylpropane sulfonic acid
salt and acrylic acid or maleic acid, saturated salt, or a
combination thereof. One example of a suitable sulfoalkylated
lignin comprises a sulfomethylated lignin.
[0023] Weighting agents may be included in embodiments of the
settable compositions to, for example, increase the density of the
settable compositions. Examples of suitable weighting agents
include, but not limited to, ground barium sulfate, barite,
hematite, calcium carbonate, siderite, llmenite, magnesium oxide,
sand, salt, or a combination thereof.
[0024] Lightweight additives may be included in embodiments of the
settable compositions to, for example, decrease the density of the
settable compositions. Examples of suitable lightweight additives
include, but are not limited to, bentonite, coal, diatomaceous
earth, expanded perlite, fly ash, gilsonite, hollow microspheres,
low-density elastic beads, nitrogen, pozzolan-bentonite, sodium
silicate, combinations thereof, or other lightweight additives
known in the art.
[0025] Gas-generating additives may be included in embodiments of
the settable compositions to release gas at a predetermined time,
which may be beneficial to prevent gas migration from the formation
through the settable composition before it hardens. The generated
gas may combine with or inhibit the permeation of the settable
composition by formation gas. Examples of suitable gas-generating
additives include, but are not limited to, metal particles (e.g.,
aluminum powder) that react with an alkaline solution to generate a
gas.
[0026] Mechanical-property-enhancing additives may be included in
embodiments of the settable compositions to, for example, ensure
adequate compressive strength and long-term structural integrity.
These properties can be affected by the strains, stresses,
temperature, pressure, and impact effects from a subterranean
environment. Examples of mechanical property enhancing additives
include, but are not limited to, carbon fibers, glass fibers, metal
fibers, mineral fibers, silica fibers, polymeric elastomers, and
latexes.
[0027] Lost-circulation materials may be included in embodiments of
the settable compositions to, for example, help prevent the loss of
fluid circulation into the subterranean formation. Examples of
lost-circulation materials include but are not limited to, cedar
bark, shredded cane stalks, mineral fiber, mica flakes, cellophane,
calcium carbonate, ground rubber, polymeric materials, pieces of
plastic, grounded marble, wood, nut hulls, formica, corncobs, and
cotton hulls.
[0028] Fluid-loss-control additives may be included in embodiments
of the settable compositions to, for example, decrease the volume
of fluid that is lost to the subterranean formation. Properties of
the settable compositions may be significantly influenced by their
water content. The loss of fluid can subject the settable
compositions to degradation or complete failure of design
properties. Examples of suitable fluid-loss-control additives
include, but not limited to, certain polymers, such as hydroxyethyl
cellulose, carboxymethylhydroxyethyl cellulose, copolymers of
2-acrylamido-2-methylpropanesulfonic acid and acrylamide or
N,N-dimethylacrylamide, and graft copolymers comprising a backbone
of lignin or lignite and pendant groups comprising at least one
member selected from the group consisting of
2-acrylamido-2-methylpropanesulfonic acid, acrylonitrile, and
N,N-dimethylacrylamide.
[0029] Foaming additives may be included in embodiments of the
settable compositions to, for example, facilitate foaming and/or
stabilize the resultant foam formed therewith. Examples of suitable
foaming additives include, but are not limited to: mixtures of an
ammonium salt of an alkyl ether sulfate, a cocoamidopropyl betaine
surfactant, a cocoamidopropyl dimethylamine oxide surfactant,
sodium chloride, and water; mixtures of an ammonium salt of an
alkyl ether sulfate surfactant, a cocoamidopropyl hydroxysultaine
surfactant, a cocoamidopropyl dimethylamine oxide surfactant,
sodium chloride, and water; hydrolyzed keratin; mixtures of an
ethoxylated alcohol ether sulfate surfactant, an alkyl or alkene
amidopropyl betaine surfactant, and an alkyl or alkene
dimethylamine oxide surfactant; aqueous solutions of an
alpha-olefinic sulfonate surfactant and a betaine surfactant; and
combinations thereof.
[0030] Defoaming additives may be included in embodiments of the
settable compositions to, for example, reduce tendency for the
settable composition to foam during mixing and pumping of the
settable compositions. Examples of suitable defoaming additives
include, but are not limited to, polyol silicone compounds.
Suitable defoaming additives are available from Halliburton Energy
Services, Inc., under the product name "D-AIR.TM." defoamers.
[0031] Thixotropic additives may be included in embodiments of the
settable compositions to, for example, provide a settable
composition that can be pumpable as a thin or low viscosity fluid,
but when allowed to remain quiescent attains a relatively high
viscosity. Among other things, thixotropic additives may be used to
help control free water, create rapid gelation as the slurry sets,
combat lost circulation, prevent "fallback" in annular column, and
minimize gas migration. Examples of suitable thixotropic additives
include, but are not limited to, gypsum, water soluble
carboxyalkyl, hydroxyalkyl, mixed carboxyalkyl hydroxyalkyl either
of cellulose, polyvalent metal salts, zirconium oxychloride with
hydroxyethyl cellulose, or a combination thereof.
[0032] Those of ordinary skill in the art will appreciate that
embodiments of the settable compositions generally should have a
density suitable for a particular application. By way of example,
embodiments of the settable compositions may have a density of
about 4 pounds per gallon ("lb/gal") to about 17 lb/gal. In certain
embodiments, the settable compositions may have a density of about
8 lb/gal to about 17 lb/gal. Embodiments of the settable
compositions may be foamed or unfoamed or may comprise other means
to reduce their densities, such as lightweight additives. In
addition, embodiments of the settable composition may comprise
weightings agents or other means to increase their densities. Those
of ordinary skill in the art, with the benefit of this disclosure,
will recognize the appropriate density for a particular
application.
[0033] The components of the settable composition may be combined
in any order desired to form a settable composition that can be
placed into a subterranean formation. In addition, the components
of the settable compositions may be combined using any mixing
device compatible with the composition, including a bulk mixer, for
example. In some embodiments, the settable compositions may be
prepared by combining the wollastonite and pumice with water. Other
additives may be combined with the water before it is added to the
wollastonite. For example, a base fluid may be prepared that
comprises a cement dispersant, a calcium-ion source, and water,
wherein the base fluid is then combined with the wollastonite. In
some embodiments, the wollastonite and pumice may be dry blended
prior to their combination with the water. In some embodiments, the
calcium-ion source may be dry blended with the wollastonite and
pumice. Other suitable techniques may be used for preparation of
the setting compositions as will be appreciated by those of
ordinary skill in the art in accordance with embodiments of the
present invention.
[0034] Embodiments of the settable compositions may be used in a
variety of subterranean applications, including primary and
remedial cementing, among others. Embodiments may include providing
a settable composition and allowing the settable composition to
set. Embodiments of the settable compositions may comprise, for
example, wollastonite, pumice, a calcium-ion source, and water. As
used herein, introducing the settable composition into a
subterranean formation includes introduction into any portion of
the subterranean formation, including, without limitation, into a
well bore drilled into the subterranean formation, into a near well
bore region surrounding the well bore, or into both.
[0035] In primary-cementing embodiments, for example, a settable
composition may be introduced into a well-bore annulus; and allowed
to set in the well-bore annulus to form a hardened mass. The
well-bore annulus may include, for example, an annular space
between a conduit (e.g., pipe string, liner, etc.) and a wall of a
well bore or between the conduit and a larger conduit in the well
bore. Generally, in most instances, the hardened mass should fix
the conduit in the well bore.
[0036] In remedial-cementing embodiments a gettable composition may
be used for example, in squeeze-cementing operations or in the
placement of plugs. By way of example, the settable composition may
be placed in a well bore to plug a void or crack in the formation,
in a gravel pack, in the conduit, in the cement sheath, and/or a
microannulus between the cement sheath and the conduit. In another
embodiment, the settable composition may be placed into a well bore
to form a plug in the well bore with the plug, for example, sealing
the well bore.
EXAMPLES
[0037] To facilitate a better understanding of the present
invention, the following examples of certain aspects of some
embodiments are given. In no way should the following examples be
read to limit, or define, the entire scope of the invention.
Example 1
[0038] The following series of tests was performed to evaluate the
mechanical properties of settable compositions comprising
wollastonite and pumice. Six different settable compositions,
labeled Samples 1-6, were prepared using the indicated amounts of
water, wollastonite, pumice, lime, and a cement dispersant. The
amounts of these components in each sample are indicated in the
table below with "% by wt" indicating the percent of the component
by combined weight of the wollastonite and pumice and gallon per
sack ("gal/sk") indicating the gallons of the respective component
per 94-pound sack of the wollastonite and pumice. The dispersant
used was CFR-3.TM. cement friction reducer, from Halliburton Energy
Services, Inc., Duncan, Okla.
[0039] After preparation, the settable compositions were allowed to
cure for 48 hours in a 2''.times.4'' metal cylinder that was placed
in a water bath at 180.degree. F. to form set cement cylinders.
Immediately after removal from the water bath, destructive
compressive strengths were determined using a mechanical press in
accordance with API RP 10B-2. The results of this test are set
forth in the table below.
TABLE-US-00001 TABLE 1 Ingredients 48 hr Cement Comp. Density Water
Wollastonite Pumice Lime Dispersant Temp Strength Samples lb/gal
gal/sk % by wt % by wt % by wt % by wt .degree. F. PSI 1 14.2 5.59
30 70 5 0.5 180 519 2 14.2 5.85 40 60 5 0.5 180 550 3 14.2 6.11 50
50 5 0.5 180 452 4 14.2 6.14 50 50 5 0 180 234 5 14.2 6.35 50 50 10
0 180 272 6 14.2 6.79 75 25 5 0 180 170
[0040] Based on the results of these tests, settable compositions
comprising wollastonite and pumice can develop acceptable
compressive strengths. For example, in Sample 1, a compressive
strength of 519 psi was obtained by including 30% bwoc wollastonite
and 70% bwoc pumice. In Sample 2, a compressive strength if 550 psi
was acquired by including 40% bwoc wollastonite and 60% bwoc
pumice.
Example 2
[0041] The following series of tests was performed to evaluate the
fluid loss of settable compositions comprising wollastonite and
pumice. Four different settable compositions, designated Samples
7-10, were prepared using the indicated amounts of water,
wollastonite, pumice, lime, a cement dispersant, a cement retarder,
and a fluid-loss-control additive. The amounts of these components
in each sample are indicated in the table below with "% by wt"
indicating the amount of the component by combined weight of the
wollastonite and pumice and gallon per sack ("gal/sk") indicating
the gallons of the respective component per 94-pound sack of the
wollastonite and pumice. The cement dispersant was CFR.RTM.-3
cement dispersant from Halliburton Energy Services, Inc. The cement
retarder was HR.RTM.-5 cement retarder from Halliburton Energy
Services, Inc. The fluid-loss-control additive was Halad.TM.-344
from Halliburton Energy Services, Inc.
[0042] After preparation, the sample settable compositions were
poured into a pre-heated cell with a 325-mesh screen and a
fluid-loss test was performed for 30 minutes at 1,000 psi and
180.degree. F. in accordance with API RP 10B-2. The results of this
test are set forth in the table below,
TABLE-US-00002 TABLE 2 Ingredients Fluid-Loss- API Cement Cement
Control Fluid Density Water Wollastonite Pumice Lime Dispersant
Retarder Additive Loss.sup.1 Sample lb/gal gal/sk % by wt % by wt %
by wt % by wt % by wt % by wt cc/30 min 7 14.2 5.83 40 60 5 0.5 0.5
0.25 87.8 8 14.2 5.81 40 60 5 0.5 0.5 0.5 152.4 9 13.8 6.58 40 60 5
0.5 0.5 0.5 127 10 14.2 5.80 40 60 5 0.5 0.5 0.75 117.1
.sup.1Calculated API Fluid Loss
[0043] As illustrated, settable compositions comprising
wollastonite and pumice may have acceptable fluid-loss control For
example, API fluid loss of less than or equal to 117 cc/30 min were
obtained for Samples 7 and 10.
Example 3
[0044] The following series of tests was performed to evaluate the
thickening time of settable compositions comprising wollastonite
and pumice. Three different settable compositions, labeled Samples
11-13, were prepared using the indicated amounts of water,
wollastonite, pumice, lime, a cement dispersant, and a cement set
retarder. The amounts of these components in each sample are
indicated in the table below with "by wt" indicating the amount of
the component by combined weight of the wollastonite and pumice and
gallon per sack ("gal/sk") indicating the gallons of the respective
component per 94-pound sack of the wollastonite and pumice. The
settable compositions had a density of 14.2 lb/gal. The cement
dispersant was CFR.RTM.-3 cement dispersant from Halliburton Energy
Services, Inc. The cement set retarder used was HR.RTM.-5 retarder,
from Halliburton Energy Services, Inc., Duncan, Okla. After
preparation, the thickening times, which is the time required for
the compositions to reach 70 Bearden units of consistency, were
determined at 180.degree. F. in accordance with API RP 10B-2
TABLE-US-00003 TABLE 3 Ingredients Cement Cement Thickening Density
Water Wollastonite Pumice Lime Dispersant Retarder Time Samples
lb/gal gal/sk % by wt % by wt % by wt % by wt % by wt hr:min 11
14.2 5.83 40 60 5 0.5 0.5 12:00+ 12 14.2 5.84 40 60 5 0.5 0.25 6:23
13 14.2 5.84 40 60 5 0.5 0.1 2.42
[0045] As illustrated, settable compositions comprising
wollastonite and pumice may have acceptable thickening times. For
example, thickening times from over 12 hours to just under 2.5
hours were seen in Samples 11 and 13, respectively.
Example 4
[0046] The following series of tests was performed to further
evaluate the compressive strength of settable compositions
comprising wollastonite and pumice. A single settable composition,
labeled Sample 14, was prepared using the indicated amounts of
water, wollastonite, pumice, lime, a cement dispersant, and a
cement set retarder. The amounts of these components in each sample
are indicated in the table below with "% by wt" indicating the
amount of the component by combined weight of the wollastonite and
pumice and gallon per sack ("gal/sk") indicating the gallons of the
respective component per 94-pound sack of the cementitious
component. The settable composition had a density of 14.2 lb/gal.
The cement set retarder used was HR.RTM.-5 retarder, from
Halliburton Energy Services, Inc., Duncan, Okla.
[0047] After preparation, the 24-hour and 48-hour compressive
strengths were determined for the sample settable composition using
an Ultrasonic Cement Analyzer ("UCA"), available from Fann
Instrument Company, Houston, Tex. In the UCA, the sample cement
compositions were cured at 180.degree. F. while maintained at 3000
psi. After removal from the UCA, the destructive compressive
strength of the sample was determined using a mechanical press in
accordance with API RP 10B-2.
TABLE-US-00004 TABLE 4 UCA UCA 48-Hour Ingredients 24-Hour 48-Hour
Comp. Cement Cement Comp. Comp. (Crush) Density Water Wollastonite
Pumice Lime Dispersant Retarder Strength Strength Strength Sample
lb/gal gal/sk % by wt % by wt % by wt % by wt % by wt PSI PSI PSI
14 14.2 5.84 40 60 5 0.5 0.25 832 900 568
[0048] Accordingly, Table 4 indicates that acceptable compressive
strengths may be obtained for settable compositions comprising
wollastonite and pumice. For example, a compressive strength of 900
PSI was obtained at 48 hours in Sample 14.
[0049] It should be understood that the compositions and methods
are described in terms of "comprising," "containing," or
"including" various components or steps, the compositions and
methods 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.
[0050] 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.
[0051] Therefore, the present invention is 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, as the present invention 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 invention covers
all combinations of all those 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 the present
invention. 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.
* * * * *