METHODS AND COMPOSITIONS COMPRISING CEMENT KIL DUST
HAVING N ALTERED PARTICLE S E
AC R0
0 j n general well treatments include wide variety d thai may fee
performed in oil, gas, ge lhe al and/o water wells, as drilling, completion arid
workover methods. The drilling, completion and or ver methods may include, but not
to , drilling, fracturing, a id ng, logging, gravel packing, perforating
conformance methods. Man of these we l treatments are designed to enhance and/or
facilitate the recovery of desirable i from a subterranean well
[0002] In cementing such well construction and remedial cementing
e compositions are commonly utilised. As used herein, the term setta e
composition" refers to a composition^) tha hydra aity of otherwise develops
compressive strength. Settable compositions may be used i primary cementing operations
whereb pipe strings, such as casing an liners, are cemented in well horn s in performing
primary cementing, settable composition may e pumped into a s between a
subterranean formation and the pipe string disposed in the subterranean formation, The
settahle composition should set in the annul us, thereby forming an annular sheath of
hardened cement (e.g., a cement sheath) that should support position the pipe strin n
the well horn and bond the exterior surface of the pipe string to the walls of the we l bore.
Settahle compositions also he in remedial cementing such as the
placement of cement plugs, and in cementing for sealing voids in a pipe string,
cement , gravel pack, formation, and the like, Settable compositions may also he used
in surface applications, fo example, construct o cementing.
[0003] Settable compositions for use i subterranean formations may further include
Portland cement. Portland cement generally is a major component of the cost for the cement
compositions. Other components may e included in the cement composition in addition to,
or in place of, the Portland cement Such components ma include fly ash, slag, shale,
zeolite, metakaolin, pumice, perlite, lime, siilea nee-hull ash, micro-fine cement, lime kiln
dust and the like. However, the operating conditions for wells ar becomin more
challenging and demandin and the search for new materials continues to meet these
challenges.
SUMMARY
[0005] An a subterranean treatment The etho
may introducing a treatment fiusd into a subterranean formation, the
treatment fluid comprises cement kiln dust having a mea particle ske that has been altered
from original size by grinding, separating, or combination thereof
[0006 Another embodiment discloses a subterranean treatment ethod The
method may comprise introducing a treatment f aid into a subterranea n formation, wherein
the treatment fluid comprises e e en kiln dust having particle size that has been
reduced from its original ske.
[0007] Another embodiment discloses a subterranean treatment method. The
method may comprise introducing a treatment fluid into a . subterranean formation, where in
the treatment fluid comprises cement kiln dust that has been ground.
[0008] Another embodiment discloses method of preparing cement ki l dust Th
method ay comprise providing cement kiln dust having an original particle size. The
method ma further comprise altering the mean particle of the cement kiln dust from th
original particle size by grinding, separating, or a combination thereof.
[ J Another embodiment discloses well treatment fluid. The well treatment
fluid may comprise cement k l d ust having a mean particle si.¾e that has been altered from
its original part e ske by grinding, separating, or a combination thereof
[0 0] Another embodiment discloses an additive for a set b le composition. The
additive may comprise cement kiln d ust having a mean particle siz that has been altered
f om its original particle by grinding, separating, or a combination thereof
[001. The features and advantages of the present o will e readily apparent
to those skilled in e art While numerous changes ma he ade y those skilled in the art
such changes ar within the spirit of the invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
[00 12 di n of the sellable compositions of the present invention comprise
cement kiln havi g a mean particle tha has been altered from s origins! T e
ea particle size of the cement kiln dus ro sy be altered, for example, to selectively
Increase or decrease the particle e as desired for a particular n,
[ J 1 embodiments of the present invention, altering the mean particle size of
the cement kiln dust may improve one or properties of th cement k ln dust, including
the void-tilling properties, gelation and compressive strengths. n em o ments,
the mean particle size o f the cemen t kilo dust may b selectively altered based on th s i e o f
voids t be filled, which be beneficial i remedial cementing m for m -. For
example, the mean particle size of the cement kiln dust may be optimized to more effectively
fill voids in a pipe string, cement sheath, gravel pack, formation, or the like. n some
embodiment t s belie ved that altering the mean particle size of the cement kiln dust may h
used to adjust the gelation time of compositions containing the cement kiln dust. n some
embodiments, the mean particle size of the cement kiln dust may be reduced to provide an
increase n compressi ve .strength. For example, reducing mean particle size of the cement
kiln dust t less than about microns has been shown to provide unexpected increases i
compressive strength for settable compositions to which the cement kiln dust may e added,
especially when compared to use of the cement kil dust pr io to the size reduction.
00 ] In some embodiments, the mean particle size of th cement kiln dust be
reduced from ts original size to provide an increase n compressive strength of a least about
5%, for example an increase in an amount in a range of at least about 5% to about 0%, n
specific embodiments, the mean particle size of the cement ki l dust may he reduced to
provide an increase in compressive strength of at least about 20%, at least about 40%, at feast
about 60%, at least about 80%, or at feast about 00%, It should he understood that, as used
herein, an increase n compressive strength for the cement ki n dust having a reduced .mean
particle size refers to a comparison of the compressive strength of a settable composition
comprising the reduced particle si¾e cement kiln dust to a settable composition comprising
the original cement kiln dust prior to the particle size reduction, The compressive strength
may be determined using either a destructive or non-destmctive testing method. In some
di , the strength tests may he performed in accordance with API P
Practice B 2 m P cl c fi r Testing We ! m First Edition, July 2005,
For example, the 244>our compressive strength for settable composition comprising the
cement kiln dust may e determined using an Ultrasonic Cement Analyzer from Fann
t s Houston, Texas, while maintained at I4 'F and 8,000 pounds per square inch
i . In one particular example, th 24-hour compressive strengths may he for
set a le composition having a density of about 2 pounds per gallon ("lh/ r ,
[00 5] Cement kil that term is used herein, refers to a partial y calcined
kiln feed which is .removed .from the gas stream and collected, for example, in a dust
collector during the manufacture of cement The cement "kiln dust generally may exhibit
e en itio s properties, in that it may set and harden n t presence of water. Usually, large
quantities of cement kiln dust are collected in the production of cement that are com onl
disposed of as waste. Disposal of th cement kiln dust can add undesirable costs to the
manufacture of the cement, as well as the environmental concerns associated with its
disposal The chemical analysis of th cement ki n dust from various cement manufactures
varies depending on a of factors, including particular kiln f d, the efficiencies of
the cement production operation, and the associated dust collection s . Cement ki
dust generally comprise a variety of oxides, such as i ¾ ¾, CaO, g ,
[0 6 In accordance with present embodiments, the m particle siz of the
cement kiln dust ca be altered using any suitable technique including, without limitation
grinding or separating to provide a material having an particle size. Separating the
cement kiln dust include sieving or any other suitable technique for separating the
cement kiln dust to provide a mean particle size tha has been altered from Its original size.
For example, sieving may be used to produce cement kil dust having an increased or
reduced mean particle size as desired r particular application. By way of further example,
grinding may be used to decrease the mean particle size of the cement ln dust.
Combinations of grinding a nd separating may be used i some embodiments. The term
gr nd or "grinding' 5 as used herein means using a grinder (e.g., ball mi l, rod mill, etc.) to
reduce the particle siz of the specified components). An example of a suitable grinder is an
8000 xe ii ball mill, available from PEX Sample Prep. In some embodiments, the
cement kiln dust may be ground for a time period in a range of from abou 30 minutes to
about hour.
[0017] The particle size of the cement kiln dust ca e altered t any size
suitable for use in cementing operations. n some embodiments, the mean particle size of the
cement k l dust may be altered from ts original particle si¾e to have a mean particle size in
a range of about I micron to about 350 microns. The mean particle size corresponds to d5
values as measured by particle size analysers such as those manufactured by Malvern
Instruments, Worcestershire, United Kingdom.
In some embodiments, the particle size of the ceme t kiln of the
cement kiln dust b increased from its original size. For x l , the particle si
of the cement kiln dus a be at least 5% greater than its original z in som
embodiments, at least a portion of the cement kiln dust y b increased to s ¾e thai is In a
range of f m about 5% to about 0% greater than its original some embodiments,
the mean particle size may be increased to s ranging between any of and/or including
an of about 5%, about %, about %, about 20%, about 25%, about 30%, about 35%,
about 40%, about 45%, about 50%, about %, about 00%, about 65%, about 70%, about
75% about 80%, about 90%, or about 95% greate than Its of the original size.
in d the mean particle size of the cemen t kiln dust be
reduced from its original size. For example, the mean particle may be reduced in an
amount sufficient to increase h compressive strength o f th cement kiln dust. n some
embodiments, the ce en kiln may have a mean particle size that i at least 5% less than
its original size. n some embodiments, at least a portion of the cement kiln dust may b
reduced to have a mean particle size in a range of from about 5% to about 95% of its i a
size. For example, the mean particle size may b reduced to a size ranging between any of
and/or including any of about 5%, about !ø%, about 5%, about 20%, about 25%, about
30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about %,
about ?0%, about 5%, about 80%., about 90%. or about 5% of original size. By way o f
example, the reduced particle s ze cement kil may have a mean particle s ze of less
than about 15 microns. n some embodiments, the reduced particle size cement kiln dustmay
have a e particle size of less than about 1 microns, less than about 5 microns, less
than about 4 microns, less than about 3 microns, less than about 2 microns, o less than abo u
1 micron. In specific embodiments, the reduced particle size cement kiln dust may have a
mean particle size in a range of from about 0. microns to about microns, from about 0 1
microns to about microns, or from about 1 micron to about microns. One of ordinary
skill in the art, with the benefit of this disclosure, should he able t selec a particle size tor
the cement ki n dus suitable for a particular application.
[0020] The cement k ln dust having a particle size that has been altered may be
included in the sellable compositions in an amount sufficient to provide, r example, the
desired compressive strength, gelation time, and the like. In some d the altered
particle size cement kiln dust may be present in the sellable compositions o f the present
invention in an amount in the range of from about % t 00% by weight of cemen t o s
components w e . The term. '^emeutitions components' refers to the components, or
a combination thereof, o f the settabic compositions that hydraulicaily set, or otherwise
harden, to develop compressive strength, including, for , cement kiln dust Portland
fly natural p (e.g., p l ite), slag, lime, shale, and the The altered
particle sk cement kiln dust ay be present hi an for example, ranging between
any of and/or including any of about 5% about 10%, about 1 , about 20%, about 25%
about , about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about
5%, about 70%, about 75%, about 80%, about 90%, about 95%, or 1 0% bwoc.. In specific
embodiments, the altered particle size cement kiln dust may be present In the setta i
compositions i an amount i the range o f from about 5 to 100% bwoc, f o about 50% to
100% bwoc, o from about 75% to 100% bwoc. One of ordinary skill in th art, with the
benefit of this disclosure, w l recognize the appropriate amount of the cement kiln dust
having a mears particle size thai has eo altered to include for a chosen application.
[00 1 J Embodiments o f the settable compositions may further comprise one o mot
additional additives, including, but not limited to, hydraulic cement, fly ash, slag, shale,
zeolite, etakao , pu i e , perhte, lime, silica, rice-hull ash, micro-fine cement, ime kiln
dust, and combinations thereof, and th like. In accordance with present embodiments, the
cement kiln dost having a mean particle sl¾e that has been altered may be prepared by a
process comprising intergrinding th cement kiln dust w t or more of the additional
additives to a particular desired size. For example, the ce en kiln dust and the on or more
additional additives may e inierground to a mean particle s ze of less than about 15
microns. In some embodiments, the cement ki lo dust and the one o r more additional
additives may be interground to a mean particle sk of less than about 10 microns, less than
about 5 microns, ess than about 4 microns, less than abou 3 microns, less tha about 2
microns, or less than about 1 micron. n specific embodiments, the cement kiln d st and the
one or more additional additives may be interground to a mean particle s e i a range tom
about 0 . microns to about microns, from about 0,1 microns to about microns, or fr o
about 1 micron to about microns. One of ordinary skill in the art, with the benefit of this
disclosure, should be able to select a particle size of the Interground cement kiln dust and the
one o more additional additives suitable for a particular application.
[0022] Hydraulic cement may be inc ded in embodiments of the settable
i of th present invention, A var iet 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
w th water. Suitable hydraulic cements include, but are not limited to, Portland cements,
po ¾o ana cements, gypsum cements, high stamina content cements, slag cements, silica
cements, and combinations thereof n certain embodiments, the hydraulic cement may
comprise a Portland cement, including Portland cements classified as Classes .C, G and
according to ri Petroleum institute, LR cifi c i far Maiwkds and
Testing for Well API Specification , Fifth Ju I, 990 In addition,
Portland cements suitable or use in embodiments the present invention ay also include
those classified as ASTM Type 1, II, III, , or V in some embodiments, the cement may be
present in the settabie compositions in an amount in the range of fr m about 0.1% to abo t
99% bwoc. For example, the cement may be present in an amount ranging between any of
and/or including any of about 5%, about 10%, about 15%, about 20%, about 25%, about
30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, abou 65%,
about 70%, about 5%, about 80% about S about 9 %, or about 95% bwoc. One of
ordinary ski l in the a t , w th the benefi t of this disclosure, wil recognize the appropriate
amount of cement to include for a chosen application,
[0023] F y ash ay be included in embodiments of the settabie compositions of the
present invention. A variety of f y ashes may be suitable, including fly ash classified as
Class C and Class F fl ash according to American Petroleum. Institute, API p i r
ri Testingfor i Cements, API Specification 0, Fifth Eel., July , 990 Class
C Oy ash comprises both silica and l me s that, when mixed with water, It sets to form a
hardened mass. Class fly ash generally does not contain sufficient lime, so an additional
source of calcium ions be required for th Class F f y ash to form a settabie composit ion
with water. In some embodiments, lime may be mixed with Class F fl as i an amount in
the range of about 0 % to about 25% by weight of the fly ash. to some Instances, the lime
may b hydrated lime. Suitable examples of fly as include, but are not limited to,
POZMIX* A cement additive, available from Halliburton Energy Services, nc., Duncan,
Oklahoma, Where present, the fly ash generally may be included in the sellable
compositions in an a ount sufficient to provide the desired compressive strength, density,
and/or cost n some embodiments, the Oy as ma be present in settabie compositions of
the present invention in a n amount i th range of about 0 to about 75% bwoc. In sonte
embodiments, the fly ash may be present n an amount ranging between any of and/or
including any of about 1 % about 20%, about 30%, about 40%, abou 50%, about 0%, or
about 0% bwoc. One of ordinary skill i th art, wit the benefit of th s disclosure, will
recognise the appropriate amount of the fly ash to include for a chosen application,
[0024] Slag may be included in embodiments of the settabie compositions of the
present invention. Slag generally does not contai sufficient basic material, so slag may be
used with a base to produce a settabie composition that may react with water to set to form a
hardened mass. Examples of suitable s rces of bases include, but not limited to, sodium
hydroxide, sod bicarbonate, sodium carbonate, i , and combinations thereof
present, he slag e included in h settable compositions an m
sufficient to provide the desired strength, density, and/or cost. in some
embodiments, the slag be present n settable compositions of the present invention a n
amount in the rang of about 0.1% to about 15% bwo . in some embodiments, the slag may
be present an amount ranging between any of and/or including any of about 0%, about
20%, about 30% abou 40%, abou 50%, about . or about 0% bwoe. One of ordinary
skill in the with the benefit of this disclosure, it recognize the appropriate amount of
the slag to Include for a chosen application
0.25] Shale be included in embodiments of the ta e compositions of the
present invention. A variety of shales may be suitable, Including those comprising silicon,
aluminum, calcium, and/or magnesium. A example of a suitable shale comprises vitrified
shale. Suitable examples of vitrified shale include, but are not limited RES U SEAE
FINE LCM materia! and RE U S AL COARSE L material, which are available
from Energy Services, Inc., Houston, Texas. Generally, the shale may have any particle
size distribution a desired for a particular application. In certain embodiments, the shale
may have a particle size distribution the range of about 37 microns to about 4,750
microns. Where present, the shale may be included i the settable compositions of the
present invention n an amount sufficient to provide the desired compressive strength,
density, s nd or cost. n some embodiments, the shale ay be present in settable
compositions of the present invention in an u in the range of about .1% to about 75%
bwoe. n some embodiments, the shale may fee present m amount ranging between an of
and/or including any of about %, about 20%, about 30%, about 40%, about 50%, about
60%, or about 70% bwoe. One of ordinary ski l n the art, with the benefit of th s disclosure,
will recognise the appropriate amount of the shale to include for a chosen application,
[0026] Zeolite may be included in embodiments of the settable compositions of the
present invention. Zeolites suitable for use typically may include porous alu ino- i cate
minerals that may be either a natural or synthetic material Synthetic zeolites based on
the same type of structural cel as natural zeolites, and may comprise aluminosillcate
hydrates. As used herein, the ter refers to a l natural and synthetic forms of
zeolite. Examples of suitable zeolites are described in more detail in U.S. Patent Ho.
7.445,669. An example of a suitable source o zeolite is available from the C2C Zeolite
Corporation of Calgary, Canada n some embodiments, the zeolite may be present in.
settable compositions of the present invention i an amount in the range of about 0, % to
about 75% bwoe. n som embodiments, the zeolite may be present: in an amount ranging
any of and/or including y of about 10%, about about 3 %, about 40%,
abou t 50% about 60%, or about 70% bwoc, One of ordinary skill i the art with the benefit:
of this disclosure, will recognize the appropriate amount of the zeolite to include for a chosen
application
[00:27] Metakaolin may be included in embodiments of th settable compositions of
the present invention. n , metakaolin is white pozxolan that may be by
beating kaolin clay., for example, to temperatures in the range of about to about
00 . In some embodiments, the metakaolin may be present in settable compositions of the
present invention in an amount in the range of about 0J% to about 5 bwoc. In. some
embodiments, the metakaolin may be present in an amount ranging between any of and/or
including any of about 10%, about 20%, about 30%, about 40%, about 50%, about 60%, or
about 70% bwoe. One of ordinary skill in the art, with the benefit of this disclosure, wi l
recognize the appropriate amount of the metakaolin to include fo a chosen application
[0028] Pumice may be included in embodiments of the settable eompositsorss of the
present invention. Generally, pumice s a volcanic roc that exhibits ee renti ous properties,
in tha it may set and harden i the presence of hydraied time and water, Bydrated lime may
be used in combination with the pumice, for example, to provide sufficient calcium ions for
the pu ieite to set In some embodiments, the pumice may he present in settable
compositions of the present invention in an amount in the range of about 0. % to about 75%
bwoc. in some embodiments, the pumice may be present m an amount ranging between any
of and/or including any of about 10%, about 20%, about 30%, about 40%, about 50%, about
60%, or about 70% bwoc. One of ordinary skill in the art, with the benefit of this disclosure,
will recognize the appropriate amount of the pumice to include for a chosen application.
[0 29] Perlite may be included in embodiments of the settable compositions of the
present invention. Perlite Is an ore and generally refers to a naturally occurring volcanic,
amorphous siliceous rock comprising mostly silicon dioxide and aluminum oxide. Perlite
suitable for use in embodiments of the present Invention includes expanded perlite and
unexpended perlite. In some embodiments, the perlite may comprise nn pande i perlite.
The perlite may also be ground, for example. In some embodiments, th perlite may b
present in settable compositions of the present invention in an amount n the range of about
0, % to about 75% bwoc. In some embodiments, the perlite may be present in an amount
ranging between any of and/or including any of about 10%, about 20%, about 30%, about
40%, about 50%, about 60%, or about 70 bwoc. One of ordinary skill in the art, with the
benefit of this disclosure, w ll recognize the appropriate amount of the perlite to include for a
chosen app! ieation.
3 Lime may be included in of the settable o of the
present invention, in certain embodiments, the i e be ydra ed lime. The lime be
included in embodiments of the settable eomposibous, for example form a hydraulic
composition with other components of the sellable compositions, such as the pumice, f y ash,
slag, and/or shale. Where present, the lime may e included n the settable compositions In
an amount the range o fro about 0 . % t about 25% bwoc, fo xample In so e
embodiments, the ime may be present in an amount ranging between any of and/or
including any of about 5%, about 0%, about 5%, about 20%, or about 25% bwoc. One of
ordinary skill in the art, with th benefi of this disclosure, wil recognize the appropriate
amount of the lime t include for a chosen application
[003 j Silic may be included in embodiments of the sellable compositions of the
present invention. Silicas suitable t r use typically may include amorphous silica, crystalline
silica, or combinations thereof Crystalline silica s a powder that may included i
embodiments of the settable compositions, or example, to prevent cement compressive
strength retrogression. Amorphous silica is a powder that may be included in embodiments
of the settable compositions as lightweight filler and/or to increase cement compressive
strength. n some embodiments, the silica may b present in settable compositions of the
present invention in amount in the range of about 0. 1% to about 75 bwoc. In some
embodiments, the silica may be present in an amount ranging between any of and/or
Including an of about 1 , about 20%, about 30% about 40%, abou 50%, about 60%, or
about 70% bwoc. One of ordinary skill in the art, with the benefit of th s disclosure, will
.recognize the appropriate amount of the silica to include for a chosen application,
[0032] Rice-hull ash ma be included in embodiments of the sellable compositions
of the present invention. In general, rice-hull ash is the ash produced from the burning o i ce
hulls, which are the hard coverings of grains of rice, and may comprise primarily silica and
carbon. n some embodiments, the rice-hull ash may be present in settable compositions of
the present nventio in an amount n the range of about 0. % to about 5% bwoc. n some
embodiments, t e rice-hull ash may be s in a amount ranging between any of and/or
including an of about %, about 20%, about 30%, about 40%, about 50%, about 60%, or
about 70% bwoc. One of ordinary skill in the art, w th the benefit of this disclosure, will
re ogni e the appropriate amount of the rice-hull ash to include for a chosen application,
[0033] Micro- fine cement may be included i embodiments of th settable
compositions of the present invention. As used herein, the term "micro-fine cement" refers
to cement having a mea particle size no larger than about 5 microns, for example, n a
range of about 1 micron to about 5 microns l a so e embodiments, th micro-fiae cement
may in s iab compositions of the present invention in an amount in the range of
about C to about 75% Its some meats, the micro-fine n may be
present in an amount ringi ng between any of and/or including any of about 0%, about 2 %,
about 30% about 40%, about 50%, about 6 % , or shout 70% bwoc. One of ordinary skill i
the art, with the benefit of this disclosure, wil i the appropriate amount of the
micro-fine cement to include tor a chosen application
[0034 Lime kiln dust may be included n embodiments of th sellable compositions
of the present invention. Lime kiln dust, that term is used herein, refers to a product
generated in the manufacture of lime. The ime kiln dust ay collected, for example, by
d st control systems in the calcination of lime stone. In some embodiments, the lime kiln
dust may be present in sellable compositions of the present invention in. an in the
range of about 0 % to about 5% bwoc. In some embodiments, the ime kiln dost may he
present in an amount ranging between any o a d or including any of about %, about 20%,
about 30%, about 40%, about 50%, about 60%, or about 70% bwo One of ordinary skill in
the art, with the benefit of this disclosure, wi l recognise the appropriate amount of the lime
kiln dust to include for a . chosen application.
[0035] Embodiments of the settabSe compositions further may include water. The
water that may be used in embodiments of the compositions include, for example
freshwater, saltwater ( .g f water containing one or more salts dissolved therein), brine .,
saturated saltwater produced from subterranean formations), sea a er, or combinations
thereof. Generally, the water may b from any source, provided that the water does not
con tain an of compounds that may undesirably affect other components n the sellable
composition. In some m the water may e included In amount sufficient to
form a p pable slurry. In some embodiments, the wate may be included in the settahle
composit ions of the present invention in an amoun t in the range of about 40% to about 200%
bwoc. For example, the water may be present amount ranging between any of and/or
including any of about 50%, about 75%, about 100%, about 125%, about 1.50%, or about
175% bwoc. In specific embodiments, the wate may b included in an amount in the range
of about 40% to about 0% bwoc. One o ordinary skill in the art, with the benefit of this
disclosure wi l recognize the appropriate amount of water to include for a chosen
application
[0036] Optionally, other additional additives may be added to the sellable
compositions of the present invention as deemed appropriate by one skilled in the art, wit
the benefit of this disclosure. Examples of such additives include, but ar not limited to,
strength-retrogression additives, set accelerators, weighting agents, lightweight additives,.
1
gas-generating , & ic l p p rty- han ift additives, lost-circulation
materials, ilrra n- ro additives, d spersa ts, f d o s ontr S additives, defeating
foaming agents, oit s e !a le particles, ate e e particles, t ixo r ic
additives, t Specific examples of these, and , additives include
salts, fibers, hydratable clays, microspheres, elastomers, eSastornerie panicles, resins, laics,
combinations thereof, and the like, A r having ordinary skill In the art, with the benefit
of thi disclosure, w ll readily be able to determine the type and amount of additive useful for
a particular application and desired result. Embodiments of the sellable compositions ay
be foamed and/or extended as desired y those of ordinary skill n the ar t
|0 37| The settable compositions of the present invention should have a density
suitable for a particular application as desired by those of ordinary skill in the art, with th
benefit of this disclosure. n som embo ents, the settable compositions hav a
density i the range of from about b/p to about ih/ga!. n othe embodiments, the
settable compositions may e foamed to a density In the range of from about 8 lb/gal to
about Ib/ga
[0 38] While the settable compositions ma be suitable for a number of different
cementing operations, they may he particularly suitable for methods of cementing in a
formation. For example, the settable compositions may he used in primary and
remedial cementing operations i which the settable compositions may be introduced into a
subterranean formation and allowed to set. As used herein, introducing the settable
composition into a subterranean formation includes introduction int any portion of th
subterranean formation, including, without limitation, into a well bore drilled nto the
subterranean formation, into a near well bore region surrounding th well bore, or nto both,
[0039] In primary cementing embodiments, for example, a settable composition may
be introduced nto a space between a wall of a well bore and a conduit . p pe strings,
liners) located n the well bore, the well bore penetrating the subterranean formation. Th
settable composition ma be allowed to set to an annular sheath of hardened cement in
the spac between the well bore wall and the conduit. Among other things, the set settable
composition may form a barrier, preventing the migration of fluids in the well bore The set
settable composition als may, for example, support the conduit in the well bore.
[0040] In remedial cementing embodiments, a settable composition may be used, for
example, in s «e ¾-ce tra g operations or in the placement of cement plugs. B way of
example, t e settable composition may be placed in a well bore to plug a n opening, such as a
void or crack, in the formation, in a gravel pack, in the conduit, in the cement sheath., and/or
a m croannul between the cement sheath and the conduit.
C While th preceding descr t ion is directed to he use o f the cemen kiln dust
having particle that has altered in cementing methods. It
should be o that embodiments* of the present technique also encompasses the of
the altered particle cement k l dust in an of a variety o f different subterranean
treatments For example, a subterranean t e method may include providing treatment
luid co p sing the altered particle s is e cement ki l dust and introducing th treatment fluid
into a subterranean formation. The cement ki n dust having a mean particle i that has
bee altered may be included in any of a number o f well treatment fluids that may be used in
subterranean treatments, including drilling fluids, completion fluids, spacer fluids,
stimulation fluids, and we l clean-up fluids. For example, a drilling fluid may comprise the
reduced particle s e cement kiln dust, wherein the drilling fluid may be circulated
downwardly through a drill pipe and drill bit and then upwardly through the web bore to the
surface. drilling fluid used ay be an number o f fluids (gaseous o li uid) and
mixtures of fluids and solids (such as so li suspensions, m and emulsions).
[004 In some embodiments, a spacer fluid may comprise the cement kiln dust
having a mea particle size that ha been altered. Spacer fluids may be used, for example, in
the displacement of fluids from well bore, in an embodiment, the fluid displaced by the
spacer fluid comprises a drilling fl uid . B way of example, the spacer fluid be used to
displace the drilling fluid from the we l bore. The drilling fluid may include, for example.
an number of fluids, s ch as solid suspensions, mixtures, and emulsions. Additional ste p
i embodiments o f the method may comprise introducing pipe string into the well bore,
introducing a cement composition into the we l bore with the spacer fluid separating the
cement composition and the first fluid. n an embodiment the cemen composition may be
allowed to set in the we l bore. Th cement composition may include, o r example, cement
and water.
[0043] Accordingly, embodiments of the present invention disclose methods and
compositions that comprise cement kiln dust having a mean particle si¾e that has bee
altered. There may be several potential advantages to th methods and compositions o f the
present invention, only some of which ay be alluded to herein. One o f the man potential
advantages o f embodiments o f the present invention is tha reducing the particle size o f the
cement kiln dust can result in. increased compressive strength for the sellable compositions
after setting. For example, it has been shown that compositions with reduced particle si¾e
cement kiln dus have increased compressive strength as compared to use of the cement kiln
dus prior to the s e reduction. Another potential advantage is that altering the mean particle
size of the cement ki n dust may impact the gelation time of compositions containing the
1.3
cement kite dust. Vet another potential advantage is that the mean particle k of the
cement kil dust y be selectively altered, for based on the size of voids. T ns
could potentially result in more effective remedial cementing methods, as t e particle s of
the k n d st been optimked,
[0044] To iae t te better of the present invention, the following
examples of certain e of so e embodiments given. In no way should the following
examples be read to limit, or define, the scope of the invention.
EXAMPLE
0 45 The following series of tests was performed to evaluate the force resistance
properties of settabie compositions comprising cement kiln dust having mean particle si¾e
that has been reduced. Two different sample sellable compositions, designated Samples I
and 2, were prepared by adding 230 gra s o f cement kiln d m to 2673 grams of tap water
while mixing Waring blender at 4,000 rp for 5 seconds followed by mixi g at 000
rp for 35 seconds for each sample. Sample contained ngro nd cement kiln dust while
the cement kiln dust included Sample 2 was ground to a reduced panicle k e. Each of
Samples 1 and 2 was then placed in a sealed cylindrical container, 2 Inches n diameter b 4
inches i height. Each container was placed n a water bath at 4 P and allowed to cure for
96 hours. Each container was then removed from the water bath, allowed to cool, an the
ylind cal samples were demo!ded. The cylindrical samples were then placed n a Tini s
O sen tester, and the compressive strengths were determined. The compressive strength
testing was performed in accordance w th AP EP Practice B 2, Recommended c c
f r Testing Wel eme s
[0046] Sample comprised water 1 6 93% bwoc) and cement kiln dust (100%
hwoc). The cement kiln dust was ngro nd and ad a mean particle size of about .7
microns. Sample had a density of b gat.
[004?] Sample 2 comprised water (106.93% hwoc) and ground cement ki dust
(100% bwoc). The cement kiln dust n Sample 2 was ground from a mean particle s ise of
8.7 microns to a mean particle siz of 5.9 micron an 8000 er i ball n li
available from SPEX Sample Prep, Sample 2 ad a mean particle sk redaction of 68,45%.
The ement kiln dost was ground in foe grinder for time period of about 30 minutes to about
1 hour. Sample 2 had a density o f 2 h/ga .
0 4 ] The results of the compressive strength testing are provided in Table
below. The dat reported n the table below is the average of 3 tests for each of the sample
settabie compositions.
TABLE 1
e e n
CKD
Particle 96-Hr Camp
Density Water C em.p.
No ( /g ) ( bwoc) bwoc) (m ron (psi)
1 04 93 1 0 S,? 140 64.3
2 2 106,93 100 5.9 140
[0049] Example thus indicates tha reduc g the particle e of the cement k ln
dust may Increase the compressive strength of the sellable compositions as compared to
u gro nd cement kiln At 4 0 !%for example. Sample 2 with cement kiln t g und
to a mean particle size of 5.9 microns had a 96~ o r compressive strength of 9.5 psi as
compared to a 96-hour compressive strength . 64.3 psi for Sample 1wit ngro nd cement
kiln dust.
EXAMPLE 2
50 additional series of tests was performed to further evaluate the force
resistance e e of scttab!e compositions comprising cement kiln dust hav a mean
particle size that l as been reduced. Two dii¾re«t sample compositions, designated
Samples 3 and 4. were prepared by adding 200 grains of cement kiln dust to . grams of
tap water while mixing n a Waring blender at 4,000 rptn tor 5 seconds followed by mixing
at 2 .000 rpm for 35 seconds for each sample. Sample 3 contained g nd cement kiln
dust while the cement ki n dust in Sample 4 was ground to a reduced particle. Each of the
samples was then placed in an Ultrasonic Cement Analyzer ( A from F nn instruments,
Houston, n th GA, th compressi ve strength of each sample was determined over
time at 0 * and 8,000 psi. The compressive, strength testing was performed in accordance
with API P Practice I .B 2 m Practice fi r Testing G m .
[005 1 Sample 3 comprised water (106.93% bwoc) and cement kiln dust ( 0%
bwoc). The cement kiln dust was un ro i and ad a mean particle size o f about 8.
microtis. Sample 3 had a density of J2 lb/gal.
[00521 Sample 4 comprised water (106.93% bwoc) and ground cement ki l dust
(100% bwoc). The. cement kiln dust in Sample 4 was ground from a mean particle st¾e of
.7 microns to a mean particle siz o f 9. microns using an 8 0 Mi er/lv i ball mi
available from SP X Sample Prep. Sample 4 had a mean particle size reduction of 48. 3%
The cement kiln dust was ground i the grinder for time period of about 30 minutes to about
hour. Sample 4 ha a density of 1 b/ga .
[0053] The re suits of the compressive strength testing a s provided in Table 2
below. The data r por ;ed in the table below compressive strengths reported by the OCA at
hours and 24 hours.
TABLE
€ s
[0054] 2 thus indicates that .reducing the particle of the cement kiln
dust may increase the compressive strength of the sellable compositions as compared to
unground cement kil dust. At !40 F, for example. Sample 4 with cement kiln dust ground
to a particle of 9 7 microns had 2 ho r compressive strength of 298 p as
compared to a 12-hour compressive strength of 153 psi for Sample 3 with ngro nd cement
kiln dust.
[0055] S should be understood that the compositions and methods are described in
terms of "comprising," "containing,' or various components or steps, the
compositions and methods can. also ''consist essentially of * or "consist of * th various
components and steps. Moreover, the indefinite articles "a" or "aiV as used in th claims,
r defined herein to mean one or more than one of the element that it introduces,
[0056] For the sake of brevity, only e 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 front any lower limit ay be combined with
an other lower limit to recite a range no explicitly recited, in the same way, ranges from
any upper limit may be combined with any other upper li it to recite a range no explicitly
recited. Additionally, whenever a numerical range wit a lower limit and an upper limit is
disclosed, any number and any nclude range fallin withi th range is specifically
disclosed i n particular, every range of values (of the form, "from about a to about b, r,
equivalently, " m approximately a to b,- * or, equivaiently, approximately a- }
disclosed herein is to be understood to set forth every number and .range encompassed within
the broader range of values even if not explicitly recite. Thus, every point or Individual
value may serve as its own lower or upper limit combined with any other point or individual
value or an other lower or upper limit* to recite a range not explicitly recited.
[005?] Therefore, the present invention is well adapted to attain the ends and
ad vantages mentioned as well as those that ar inherent therein. The particular embodiments
disclosed above are illustrative only, as the present invention be modified and practiced
n different but equivalent manners apparent to .skilled n the rt having t benefit of
the teachings herein. Although individual embodiments are discussed, the invention cover
all combinations of ail those n . no .limitations are intended to the
details of construction or herein shown, other than as described in the claims below.
A so, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly
and clearly defined b the patentee, It is therefore evident that the particular illustrative
embodiments disclosed above may be altered or modified and a l suc h variations are
considered within the scope and spirit of the present invention. If there is a y conflict in the
usages of a word or term in this specification and one or more parentis) or other
tha be incorporated herein b reference, th definitions that are consistent with this
specification should he adopted.

What is claimed is;
, A subterranean treatment comprising:
introducing a fluid into a subterranean Ibrrnation, the
treatment fluid comprises n k ln dust .having a mean particle size that has been altered
by grinding, e , or a combination thereof.
2, The method of claim 1 wherein the mea particle size of the cement kiln dust
is at least 5 greater than its original
3, The method of clai I wherein the mean particle size of the cement kilo dust
is a least 5% ess than its original size,
4 , The method of claim 1 wherein the mean particle s t e of the cemen t kiln dust
.is s range of about I micron about 350 microns.
5, The method of clai wherein the treatment fluid s a seti h e composition,
6 A subterranean treatment method comprising:
introducing fluid into a subterranean formation, wherein the
treatment fluid comprises cement la dust having a m particle size tha has been reduced
fro its original .
, The method of claim 6 wherein the mean particle size of the cemen kil dust
is less than about microtis.
. The method of c laim wherein the mean particle of the cement ki n dust
is n a range of f om about 5% to about 95% of its original i
9, The method of claim f wherein the mean particle s of the cement kiln dust
has been reduced by grindi ng, separating, or a combi atio thereof.
, The method of claim h wherein the treatment fluid comprises a -fluid selected
i m the group consisting a drilling fluid, a . completion fluid, a spacer fluid, a stimulation
-fluid, a wel clean up fluid, and any combination thereof.
, he method o f claim 6 wherein the treatment fluid is a composition,
and wherein th method further comprises allowing the settable composition t se in the
subterranean formation.
2 The method of claim. wherein the mean particle si¾e of the cement kiln
dust has been reduced in an amount sufficient to provide an increase in 24-hour compressive
strength o f a least about 5% as measured using an Ultrasonic Cement Analyzer while
maintained at 14 and 3,000 ps .
3, The metho of claim 1 wherein the mean particle size of the cement kiln
dust ha bee reduced in a n amount sufficient to provide an increase i 24-hour compressive
strength of at s about 50% measured using Ultrasonic Cement Analyzer while
maintained at i40 and 3,000 ps .
14, The method of claim I wherein the ce ent kiln dust is present in the
setiable composition an amount n a range o from about !% to 100% b weight of
e itio s components n the setiable composition,
15 'The method of I wherein the cement kil dust was prepared by a
comprising tergr d g cement kiln dust with additional d ti
16, The method o claim 15 wherein the additive comprises an
additive selected from the group consisting of hydraulic cement, fly ash, slag, shale, xeollfe,
me a otin, perilfe, ime, lime kiln dust, silica, rice-hull ash, micro-fine cement, and
any combination thereof,
, The method of claim wherein water is present in t e setiable composition
n an amount sufficient to a p pab ie slurry,
, The method of claim wherein the sellable composition further comprises
a n additive selected from the group consisting o f a set retarding additive, a strengthretrogression
additive, a set accelerator, a weighting agent, a lightweight additive, a gasgenerating
additive, a nteehanieahproperty-enhancSng additive, a lo t- ire iatio mate al a
i lir a t o n contro! additive, a dispersant, a i u d oss-eon ro additive, a de&aming agent, a
foaming agent, an oil-sweliahle particle, a w ier w ab!e particle, a ihix trop additive,
and any combination thereof
. The method of claim 11 wherein the setiable composition further comprises
a additive selected from the group consisting o f hydraulic cement, f y ash, slag, shale,
zeolite, eta ao in, pumice, per ke, l me, l me kiln dust, silica, rice-hull ash, micro-fine
cement, a salt, a fiber, a hydratabie clay, a microsphere, an elastomer, an e!a tome c
particle, a resin, a latex, and any combination thereof,
20. The method of claim 1 wherein he setiable composition is introduced i to a
space between a pipe string and a well bore wall .
A subterranean treatment method comprising:
introducing a treatment fluid nto a subterranean formation, wherein the
treatment fluid comprises cement kiln dust that has been ground.
22. 'The method of claim wherein the cement ¾ n. dust has a mean particle
ske of less than about S microns,
23. The metho of claim 2.1 wherein the cement kiln dust has a mean particle
si i a range o f from about 5% to about 95% of its original particle si¾e.
24. The d of claim 2 1 wherein the treatment fluid comprises a fluid
selected from th group consisting a drilling t . a completion l ic a spacer fluid,
stimulation d a well clears up fluid, and soy or ination e
25. The method of claim 2 wherein the treatment fluid is a settabie composition,
and wherein the method sr her comprises allowing the se l abl composition to set in the
subterranean formation.
The method of claim 25 wherein the mean particle s e o f the cement ki ln
dust ha been reduced in an amount sufficient to provide an increase in 24-hour compressive
strength of at least about 5% as measured u n an Ultrasonic Cement Analyser while
maintained at 0 F a d 3,000 ps
27. The .method of claim 25 wherein th mean particle s e of the cement kiln
dust has been reduced in an amount sufficient to provide an increase in 24-hour compressive
strength of a least about 50% as measured using an Ultrasonic Cement Analyzer while
maintained ai 4 and 3,000 ps .
28, The method of claim 25 wherein the cement kiln dus i present in th
settabie composition in an amount in a range of from about % to about 50% by weight of
eernentitious components in the settabie composition.
29, The method of claim 2 wherein the cement kiln dust is present in the
settabie composition i n a amount n a range of from about 50% to 0% by weigh of
eementiOous components in th settab e composition.
30, The method o f claim 25 wherein the cemen kiln dust was prepared by a
process comprising intergrinding cement k ln dust with an additional additive,
, The method of claim 30 wherein t e additional additive comprises an
additive selected from the group consisting of hydraulic cement, fly ash, slag, shale, zeolite,
metakao m, pumice, perliie, lime, lime kiln dust, silica, rice-hull ash, micro-fine cement, and
any combination thereof
32, The method of claim 25 wherein water is present i the settabie composition
i an amount sufficient io form pun pa ie slurry,
33 The method of claim 25 wherein the settabie composition further comprises
an additive selected from the group consisting of a set retarding additive, a strengthretrogression
additive, a set accelerator, a weighting agent, a lightweight additive, a . gasgenerating
additive, a mechanlcal-piOperty-enhaneing additive, a lost-circulation material, a
flltmtion-conirol additive, a disp rsa , a f id ioss-cors ro additive, a def an ing agent, a
foaming agent, an ol sw ilable particle, a water -swe ia e particle, a thixstrople additive,
and a y combination thereof
34 The method of claim 25 wherein the settabie composition further s
n additive fr the group n of hydraulic cement, y slag, e,
zeolite, n eiakao in pumice, pe ite, in t , k ln dust, silica, rice-hall ash, micro-fine
cement, a salt, a iber , a hydratsble clay, microsphere, elastomer, an ela to er i
particle, a resin, a latex, and any combination thereof
35. The method of clai 25 wherein the se tah e composition is introduced nto a
space between a pipe string and a w ll bor wall.
36. A method of preparing cement ki l dust comprising:
providing cement kiln dust having an original particle size; and
altering the an particle s ze of the cement kiln dust from the original size
b grinding, separating, or a combination thereof
37. The metho of claim 36 wherein the particle i¾e of the ee ent kiln
dust is altered to at least 5% greater than its original size.
3 . The method of claim 36 wherein the mean particle s ze of the cement kiln
dust altered to at least 5 les than it original size.
39. A we treatment fluid comprising:
cement kil dns having a mean particle e that has been altered from its
original si¾e by grinding, separating, or a combination thereof
40. The wel treatment fluid of claim 39 wherein the mea particle size of the
cement k ln dust has been altered to at least 5% greater than its original size,
41. The well treatment fluid of claim 39 the mean particle size of the
cement kiln dust has been altered to at least 5% less than Its original size.
42. A n additive for a se a le composition comprising?
cement kiln dust having a mean particle size that has been altered from its
original ize by grinding, separating, or combination thereof.
43. The additive of claim 42 wherein the mean particle size of the cement kiln
dust has been altered to at least 5% greater than its original .
44. The additive of claim 42 wherein the mean particle s ze of th cement kiln
dust has been altered to at least 5% less than Its original size,