CA2210873A1 - Silicate solutions - Google Patents
Silicate solutionsInfo
- Publication number
- CA2210873A1 CA2210873A1 CA 2210873 CA2210873A CA2210873A1 CA 2210873 A1 CA2210873 A1 CA 2210873A1 CA 2210873 CA2210873 CA 2210873 CA 2210873 A CA2210873 A CA 2210873A CA 2210873 A1 CA2210873 A1 CA 2210873A1
- Authority
- CA
- Canada
- Prior art keywords
- silicate
- weight
- solution
- pyrophosphate
- hydroxide
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
- C09K8/02—Well-drilling compositions
- C09K8/04—Aqueous well-drilling compositions
- C09K8/14—Clay-containing compositions
- C09K8/16—Clay-containing compositions characterised by the inorganic compounds other than clay
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/20—Silicates
- C01B33/32—Alkali metal silicates
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Dispersion Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Silicates, Zeolites, And Molecular Sieves (AREA)
- Detergent Compositions (AREA)
- Emulsifying, Dispersing, Foam-Producing Or Wetting Agents (AREA)
Abstract
An alkali metal silicate solution contains an agent effective to inhibit precipitation or gelation of the silicate in the solution in the presence of divalent metal ions. The agent is a water-soluble inorganic compound containing a univalent cation other than the cation of the alkali metal silicate and an anion effective to inhibit said precipitation or gelation.
Description
-, , 17 ~UL ~V_ 'Z''~ CA 022l0873 l997-07-l8 ~ C0126 .
~ he pressn~ invention relates ~o alkali metal silicate solutions and more particularly, but not exclusively, to such solutions for use ~ in oil indu~try applications, e.g. f or use in drilling fluids . drilling muds. and oil well ~ro~king fluids. all referre~ to generically herein - zs drill~rlg ~luids.
Alkali metal sillc~te solutions ~rere exte~sively used~ in the oil ind~stry Sor such applicationQ over a pe~iod of many years. ~oweve~
more recently ~hey have fo~ the large pa~t been superseded by more sophist~ catet fluids ~ h impro~red properties. These flulds are hl~vever now gi~ing rise to environmental concerns so t~at ~ilicale so1Ytions may come ba~k ~nto favour.
Silicate ~:olutions to ho~ever have the ~isad~ran~age that they gel o~ form precipitates on reac~ion ~ith divalent metal ions (e.g. Caa~
and Mg2~ whieh are containsd ~n groundwate2~ and sea~rate-. This is obviously an unwanted reaction ~hich limits the us~fulness of sillcate ~olutions in oil indust~y applications, It is therefore an o~ject of the present invention to ob~iate or mitigate the abovementioned disadvantage.
Aceording to a ~rst aspecc of the present invention the~e i9 pro~vided an alk~li me~al ~i~icate colution containin~ an agent effective ~o ~nhibit precipita~ion or gelation of said silicate in the sol~tion in the ~ c~-ce of divalent me~al ions ~nerein said agent i5 a w~e-soluble inorganic compound containing a univalent cation other than the cation of the alkali metal silicate and an anion effecti~e to inhiblt ~aid precipitation or gelation.
The inorganic eo.,.~ound ~also referret to herein as the 'inhibiting agent') may be one for which the anion prsvents ge~aelo~
~, or precipitation of the silicate ei~her by (i) complex formation with the divalent metal.
;; (ii) precipita~ion of an in~oluble cGn,~ound o~ ehe d~valent metal~ or ~ili) reducing the degree of polylnerisation of the silicate - ~he anior~ is preferably hydroxide, ca~bona~e or phosphate. ~o or more inor~anic compounds may be used as th~ hib~tion agept to provide a combination of such anions.
17 JUL '97 15:03 CA 022l0873 l997-07-l8P-7 W0 961~Z2~S P~1GB9610012C' Tke ~erm phosphate as used herein is u~ed as a genc~ic name for a group a. compounds such as (but no~ exclusi~e~y) phosphates, orthophosphates, metaphospha~es, polyphosphates. pyrophosp~ e, elc, bu~ for t.ne plzrposes of Ihe rresent specification excludes hydro~en phosphates and dihydrogen phosphates. The inhi~iting a~ent is prsferabi~- a pyrophosphate or polyphosphate. Prefera~y the uni-~alen~ cation is an alkali :netal. If the al~ali metal silicate i5 sodium si:icate ehen the caLicr. (of the inhibitin8 agent) is other than sodium a~d ~s p~eferablv potassium.
In ~:cortance ~.rith the f~rst aspec~ of the in~ention, the cation of the ai~li metal silicate is diffe~ent from ~hat of the inhibiting agen~ ~c~ solubility reasons. The pre~e~red cation for the ~1kali metal ~licate ~ ~ sodium silicate wnereas tha~ far ~ne inhibiting agen~ is pot~csiu.... Inhibiting agents in the form of potassium salts have grcater solubility in sodium silicate solutions than the equivalsnt sodium sai~s.
We have also found tha~ the use of an alkali metal hydroxide in conjunc~ion ~ith a phosphate or c~rbonate is partir~lArly advanSageous since the hydroxide provides no~ only enhanced inh~ition of precipitation or ~elation of the silicate but al50 lower~
~he viscosity of the solution ~ithoul effecting other ~ Gp~ ties thereof. Thus the inclusion of an alkali me~al hyd~oxide, in conjunc~icn wi~h a pho~ph~~e o- caroona~e~ allo~s the viscosity of the sol~tion IO De tailored to specific needs.
As mentioned above, prefcrred inhibi~ing agents for use in the invention ir~clude carbona~es and/or phospbates. 'rhis leads to a seçond aspect of the invention according to which there is p~o~rided an alkal metal silicate so~ ion containing an agent effectlve to inhi~it p~e~ipi~ation or gelation of sait silicate in the pre~ence of d5valent metal ions ~rherein said agent is a w~er soluble inorganic compound containing a univalent ca~ion ant an anion selected f~om earbona~e and/or phosph~te, The preferred phosphate for use in accordance vith the second aspect of the inven~ion i5 pyrophosphate or polypnosphate.
For compositions in accordance ~ith Ihe second aspect o~ the invention. it is preferred (but not essential) that the cation of the inhibitio;l a~ent is other ~han the cation of ~he alkali metal ~ te '97 15-0 CA 022l0873 l997-07-l8 17 J.UL ~v~ S , rc~~ ou6 C.,...~o~itions in accordance with the second a~poct of tne inven~ion pref~rably also include th- hytroxides of a univalent ca~.o--as a viscosity rno~ifier.
Th~ invention ~both fir~t ~nd second aspoc~s) is applicable mcs;
p~ticularly to sodi~m silicate solutions. ~cr use in the invencic~, the silicate may ha~vs a wide rangs of SiO2;M,O ~eight ratios, typ~ca;l.
1,6:1 to 3.6:1. As mentioned a.bove, the preferred inhibitin8 agen~s are hydrox,des, phosphates and carbonates. We have esr~ c~P~ tha~ t;~e la~t~r ~ o agents (phosphate and carbonate) sre ~seful o~er a wi~ie range o~ SiOz:Na20 weight ra~ios. Howe~.rer if hy~roxide is to be used as the sole inhibiting agent then it is ~ost effective at SiO~ a~C
ra~ios of Z.5:1 to 3.6:1.
Gene~ally the amollnt o~ alkali metal 5ilicate solids will comprise 30 to 99% (preferably 50 to 99%) by weigh~ of the to~al weight of t.~e alkali metal eiljc~te solids and inhibition a~ent .~hich ~ill ~or, e~ondingly be 1 tO 70% ~preferably 1 to 50%) by weight on ~he same ba~is.
Within this broat range we have identified more preferret ranges which a~s deper~den~ on the inhibitlon agent(s) used and, for the more preferred ran~es. on the SiO2:~1a20 r~ltio of the si~ica~e employed.
If ~he inhibition agent is pnosphate and/or car~onate then i~ is preferred that the Qolution comprises 15 to 55% by weight of thc inhibiticn agent based on thç total wQight OI solids (silicate plu~
inhibition a~ent). To attain rn~Yimltm inhibition, the amoun~ o~
~arbona~e or phosphate is detenT ined by reference to the SiOz;Na;O
~eight ~atio ta~suming the silicate is Ro~ m silicate) in acco~dance with the following Tabl- 1.
Table 1 5iO~l'la~O Ratio Amount of Inhibition Aeen~
l.~ to 2.1 15-30%
Z,l to 2.6 20-459 - Z.6 to 3.6 35-55~6 ~
In ~he above ~able ths amount of inhibition agen~e is expresset ~7 JUL '97 15:03 CA 02210873 1997-07-18 P~9 , Y~ ~96 q as a per~centa~e of the ~o~al amount of silicate plus inhibi~ion agent.
!f the irlhibition a en~ comprises a hydroxide plus at least one other inhibi~icn agent (e.g. car~onate andlor phosphate) then it is prefe-red ~ha~ the hydrox~de comprises ~~p to 10% by weight of total solids (inhibition agent plus silicate) and the other inhib~tion agent ccmp~ises 15~6 to 609~ on the same basis. To attain ~ ~ inhibition, the amount of the 'other inhibition agen~ is deter~nirled by reference ~o ~;~,e SiO7:~ia~O weight ratio ~assumin~ the silicate i5 sodi~ silicate) ir. acc_rdance with the followin~ lable.
~able 2 SiO~ ,O Ratio A~hunl of Hvdroxide A~nount of 'other' Inh~bition A~ent 1 L ~ o 10~ 15--35~6 2.1 to 2.6 1 ~o 10~ 20-40%
2,6 to 3.6 1 to lO~ 40-60%
in the above table, the amounts of hydroxide and 'other' inhibi~ion agent are expressed as percentages of the total amount of silica~e hvdroxide an~ 'o~her' inhibition agent.
The use of a hydroxide as the sole inhibition agent is limited bS,~ ils ~bili~y to reducc ~he degree of polymerisa"ion ~.rithln the soluticr,. The preferred amount of the hvdroxide is 1 ~O 20% by ~eight (base~ on ~he ~otal weight of the hydroxide (e.g. alkali Inetal hydro.~idel and silicate). more preferably 2 to lZ~6 on the same basis.
Solu~ions in accordanee wi~h the invention may be produced in wide ran~e of concentr3tions. It will ho~ever generally be n~ost convenient initially to f ormulate more concentrated solution5 f or tr~nspor~ to the site at ~hich the solution is to be used ant then to dllu~e the "eoneentrate" do~n to the required l~se s~rength. If ~he inhibi~ing agent is a carbonate or hydroxide then such a concentraee may conYeniently be prepared by mixing a commercial ~rade of silicate solution (which would generally co~tain 35% ~o 55% by weight solidsl wi~h a solution cf ~ppropriate s~rength of the ear~onate or hydroxide. .-If hovever rhe inhibiting agent is a p~osphate. it may be more convenient to di~ute a commercial silicate solulion ~o give a solld~
con~en~ o~ 15-40~; (e8 20-259~) by weignt before admi~ture wi~h a - CA 022l0873 l997-07-l8 P.10 17 J,UL '97._15,~0~ 5 . PCTIGB9C~O
. . ~ 5 solut~on of the phosphate since it may be tifficult to obtain the solution of the phosphate ~ higher silicate concentrations.
It is also possible to provide a t~o component fiyStem comprising (i) a cor~cer~t~at~d silicate solution, and (ii) an inhibiting agent soluticn. the two solutions being mixed on sile prior to use.
Alkali metal silica~e solutions in accordance with the invention are parlicula~ly suitable ~or use in oil indus~ry applicat~on~, As such, the ~olut~ons may be for~lated into drillin~ flu~ds (including d~illin~
muds clear dr~lling fluids, workover fl~ids~ and oil ~rell workin~
ids~. Such fluids may compri~e up to 259~ bv weight, more usuaily 5-10~ by weight, of alkali metal silicate. The flu~ds may~ for example.
be used in shale st~ tion pro~es es.
The in~,rention will be illustrated by ~eterence to the followirlg non-limi~ed ~Sxamples.
Example ~
A ~ilic~te solution (dssi~nated ~ample 1) in accor~ance with ~he invent~on wa~ prepared by r~liY;rlg O,z g 50% w!W potass~um hyd~oxide solution and 1 g tetrapo~assium pyrop~ospha~e in 88.8 ~ de~ion~set wate~, Ar~ g lt~ ~ of Q79 sodium silicate sol~tion ~a-ailable ex Brunner Mond) ~nd stirring for 2 minutes. Q~9 has a SiOz:NazO weight ratio of 3.~ and a ~il;cate sol;ds content o~ 3~.1% by weight.
The tolerance of th~ solution to precipi~ation and/or gelation of the silicate ~as determined ~y t~rat~ng ~he solution with synthetic seawa~er whi~st measuring the ~u2~bidi~y of the solution by li8ht tran~mi ~sio~. The end poin~ ~a~ determined by the point at which li~ht dispersion cA~ses a d~op in t~ansmi~et light iue to the inte~ention cf particulate matter. The ~yn~he~ic seawater used in this procedure had the composition shown i:l the Hand'oook o~
ctry and Physics, 58th Edition, F-203 sa~re ~hat components having a concent~ation less than 100 ppm were excludet.
The result iB shown in Table 3.
A further sample (Sample 2) ir~ accosdance with ~he l~ention was prepared by the fiame procedure but usin~ 0.2 g 50% ~/w ~otasslum hydroxide solution, 2 ~ tetrapotassium pyrophosphate, 87.8 g ~IPio~ised water and 10 g of Q79 sodium silicate solution. The tolerance to preeipit~tion and/or gelation was measured~ as p~eviously.
-CA 02210873 1997-07-18 P.ll 17 JUL ~97_ 15,0*c PCr/GB96roOl2C
.
.l ,urlher sample ~Sample 3) cont~i~ing potas~ium hydroxide (in the amc,n; sho~rn ~n ~able 3: but no tetrapotassi~m pyrophosphate ~ras also pre?areo and the tolerance measured as previously.
B~ way of comparison, Sample 4 ~hich contained ne~ ther potassium nydroxide nor ~e~rapotassium pyrophosphate was prepared and its ;oIerance also measured.
~ oe results are snown in Table 3.
' . W0 9U~22~S CA 0 2 210 8 7 3 19 9; - O 7 - 1 B P . lZ
L ~;
a ~
c2. r cr~ ~r . ~ tJ ", ' .
0 ~ E
~1 ~ 0 .,~ ~ ' .
r~ S
I ~
O O ~ O o ~0 L O O , ~J 4 _~
,, .
. ; : .
, X
h .
E ~1 .,. ~. . .
~ ~ o o o o ~~ o ~ .
.
~1 ~
rJ ~O O o ~ ~
.,, _ U ~ ,_ ., 4 E
h r.~
CA 022l0873 l997-07-l8 P.13 17 JUL '97 1~-,0 ~
.
B
1~ can be seen from Tabie 3 that all of Sa,mples 1 to 3 show superior tolerance to precipitzlion~gelation than Sample 4 which d~d not con~ain an inhibition agen~. The result ~as best for Samp}e 2.
l~xam~le Z
A sil.cate solution ~a5 prepared by t3king 1 g 50% ~~/w potassium c~oxite ~nd 10 ~ ;n~ telrasot.um pyrophospha~e with 30 g deior~eed waler. adding So g Q79 sodi~m siilcate and stirring for Z minutes.
A 2~ ~ aliquo~ Or ~he solu~ion ~as made ~Ip to 100 g wit~ deioniset ~~ater and ~ested for its tolerance ~o sea waeer ag described in Example 1 ~bove. The result was s-~bs~an~ially th~ same as for sample 1 ~Examp1e 1 ) above.
Exam~l- 3 Using a sodium 5ilicate soiution ha~ g a solids content o~ 53.5%
and a SiO2:::a~0 ~eight ra:io of 2, Samples g and 5 ko~r~rative) having the composition sho-~n in Table 4 wer~ prepared. The sàmples were tes~ed for ~heir tolerance to sea-/ater as de~cribet in Example 1 abo~.~e.
The resul~s are shown in TAble 4 and once again the supe~ior result obtained b~ the p~esence OI po~assiu~ hydroxide and ~etrapot~ssium pyrophosp~.ate (as compareA ~o r.o inhibi~ing a-gent al all) are clearly temonc~rated.
CA 022l0873 l997-07-l8 P.14 17 JUL ' 97, . _15 :,05"~5 . BCT/GB9~UOO~
, O ,~.~
r C
~U
Ul ~
:~ U
O ~ E O --e ~
.u ~ C4 o o ~0 . oo n ~ o . . ..
_, ~
~, .p E
.~ ~ .
Dl ' O O
O
o _ a ~
~ ~ .
.. ~ .
r 8 t" o '- ~ O o ~ ~1 Ir 01 .
_l C
E
U~ Ul ~o
~ he pressn~ invention relates ~o alkali metal silicate solutions and more particularly, but not exclusively, to such solutions for use ~ in oil indu~try applications, e.g. f or use in drilling fluids . drilling muds. and oil well ~ro~king fluids. all referre~ to generically herein - zs drill~rlg ~luids.
Alkali metal sillc~te solutions ~rere exte~sively used~ in the oil ind~stry Sor such applicationQ over a pe~iod of many years. ~oweve~
more recently ~hey have fo~ the large pa~t been superseded by more sophist~ catet fluids ~ h impro~red properties. These flulds are hl~vever now gi~ing rise to environmental concerns so t~at ~ilicale so1Ytions may come ba~k ~nto favour.
Silicate ~:olutions to ho~ever have the ~isad~ran~age that they gel o~ form precipitates on reac~ion ~ith divalent metal ions (e.g. Caa~
and Mg2~ whieh are containsd ~n groundwate2~ and sea~rate-. This is obviously an unwanted reaction ~hich limits the us~fulness of sillcate ~olutions in oil indust~y applications, It is therefore an o~ject of the present invention to ob~iate or mitigate the abovementioned disadvantage.
Aceording to a ~rst aspecc of the present invention the~e i9 pro~vided an alk~li me~al ~i~icate colution containin~ an agent effective ~o ~nhibit precipita~ion or gelation of said silicate in the sol~tion in the ~ c~-ce of divalent me~al ions ~nerein said agent i5 a w~e-soluble inorganic compound containing a univalent cation other than the cation of the alkali metal silicate and an anion effecti~e to inhiblt ~aid precipitation or gelation.
The inorganic eo.,.~ound ~also referret to herein as the 'inhibiting agent') may be one for which the anion prsvents ge~aelo~
~, or precipitation of the silicate ei~her by (i) complex formation with the divalent metal.
;; (ii) precipita~ion of an in~oluble cGn,~ound o~ ehe d~valent metal~ or ~ili) reducing the degree of polylnerisation of the silicate - ~he anior~ is preferably hydroxide, ca~bona~e or phosphate. ~o or more inor~anic compounds may be used as th~ hib~tion agept to provide a combination of such anions.
17 JUL '97 15:03 CA 022l0873 l997-07-l8P-7 W0 961~Z2~S P~1GB9610012C' Tke ~erm phosphate as used herein is u~ed as a genc~ic name for a group a. compounds such as (but no~ exclusi~e~y) phosphates, orthophosphates, metaphospha~es, polyphosphates. pyrophosp~ e, elc, bu~ for t.ne plzrposes of Ihe rresent specification excludes hydro~en phosphates and dihydrogen phosphates. The inhi~iting a~ent is prsferabi~- a pyrophosphate or polyphosphate. Prefera~y the uni-~alen~ cation is an alkali :netal. If the al~ali metal silicate i5 sodium si:icate ehen the caLicr. (of the inhibitin8 agent) is other than sodium a~d ~s p~eferablv potassium.
In ~:cortance ~.rith the f~rst aspec~ of the in~ention, the cation of the ai~li metal silicate is diffe~ent from ~hat of the inhibiting agen~ ~c~ solubility reasons. The pre~e~red cation for the ~1kali metal ~licate ~ ~ sodium silicate wnereas tha~ far ~ne inhibiting agen~ is pot~csiu.... Inhibiting agents in the form of potassium salts have grcater solubility in sodium silicate solutions than the equivalsnt sodium sai~s.
We have also found tha~ the use of an alkali metal hydroxide in conjunc~ion ~ith a phosphate or c~rbonate is partir~lArly advanSageous since the hydroxide provides no~ only enhanced inh~ition of precipitation or ~elation of the silicate but al50 lower~
~he viscosity of the solution ~ithoul effecting other ~ Gp~ ties thereof. Thus the inclusion of an alkali me~al hyd~oxide, in conjunc~icn wi~h a pho~ph~~e o- caroona~e~ allo~s the viscosity of the sol~tion IO De tailored to specific needs.
As mentioned above, prefcrred inhibi~ing agents for use in the invention ir~clude carbona~es and/or phospbates. 'rhis leads to a seçond aspect of the invention according to which there is p~o~rided an alkal metal silicate so~ ion containing an agent effectlve to inhi~it p~e~ipi~ation or gelation of sait silicate in the pre~ence of d5valent metal ions ~rherein said agent is a w~er soluble inorganic compound containing a univalent ca~ion ant an anion selected f~om earbona~e and/or phosph~te, The preferred phosphate for use in accordance vith the second aspect of the inven~ion i5 pyrophosphate or polypnosphate.
For compositions in accordance ~ith Ihe second aspect o~ the invention. it is preferred (but not essential) that the cation of the inhibitio;l a~ent is other ~han the cation of ~he alkali metal ~ te '97 15-0 CA 022l0873 l997-07-l8 17 J.UL ~v~ S , rc~~ ou6 C.,...~o~itions in accordance with the second a~poct of tne inven~ion pref~rably also include th- hytroxides of a univalent ca~.o--as a viscosity rno~ifier.
Th~ invention ~both fir~t ~nd second aspoc~s) is applicable mcs;
p~ticularly to sodi~m silicate solutions. ~cr use in the invencic~, the silicate may ha~vs a wide rangs of SiO2;M,O ~eight ratios, typ~ca;l.
1,6:1 to 3.6:1. As mentioned a.bove, the preferred inhibitin8 agen~s are hydrox,des, phosphates and carbonates. We have esr~ c~P~ tha~ t;~e la~t~r ~ o agents (phosphate and carbonate) sre ~seful o~er a wi~ie range o~ SiOz:Na20 weight ra~ios. Howe~.rer if hy~roxide is to be used as the sole inhibiting agent then it is ~ost effective at SiO~ a~C
ra~ios of Z.5:1 to 3.6:1.
Gene~ally the amollnt o~ alkali metal 5ilicate solids will comprise 30 to 99% (preferably 50 to 99%) by weigh~ of the to~al weight of t.~e alkali metal eiljc~te solids and inhibition a~ent .~hich ~ill ~or, e~ondingly be 1 tO 70% ~preferably 1 to 50%) by weight on ~he same ba~is.
Within this broat range we have identified more preferret ranges which a~s deper~den~ on the inhibitlon agent(s) used and, for the more preferred ran~es. on the SiO2:~1a20 r~ltio of the si~ica~e employed.
If ~he inhibition agent is pnosphate and/or car~onate then i~ is preferred that the Qolution comprises 15 to 55% by weight of thc inhibiticn agent based on thç total wQight OI solids (silicate plu~
inhibition a~ent). To attain rn~Yimltm inhibition, the amoun~ o~
~arbona~e or phosphate is detenT ined by reference to the SiOz;Na;O
~eight ~atio ta~suming the silicate is Ro~ m silicate) in acco~dance with the following Tabl- 1.
Table 1 5iO~l'la~O Ratio Amount of Inhibition Aeen~
l.~ to 2.1 15-30%
Z,l to 2.6 20-459 - Z.6 to 3.6 35-55~6 ~
In ~he above ~able ths amount of inhibition agen~e is expresset ~7 JUL '97 15:03 CA 02210873 1997-07-18 P~9 , Y~ ~96 q as a per~centa~e of the ~o~al amount of silicate plus inhibi~ion agent.
!f the irlhibition a en~ comprises a hydroxide plus at least one other inhibi~icn agent (e.g. car~onate andlor phosphate) then it is prefe-red ~ha~ the hydrox~de comprises ~~p to 10% by weight of total solids (inhibition agent plus silicate) and the other inhib~tion agent ccmp~ises 15~6 to 609~ on the same basis. To attain ~ ~ inhibition, the amount of the 'other inhibition agen~ is deter~nirled by reference ~o ~;~,e SiO7:~ia~O weight ratio ~assumin~ the silicate i5 sodi~ silicate) ir. acc_rdance with the followin~ lable.
~able 2 SiO~ ,O Ratio A~hunl of Hvdroxide A~nount of 'other' Inh~bition A~ent 1 L ~ o 10~ 15--35~6 2.1 to 2.6 1 ~o 10~ 20-40%
2,6 to 3.6 1 to lO~ 40-60%
in the above table, the amounts of hydroxide and 'other' inhibi~ion agent are expressed as percentages of the total amount of silica~e hvdroxide an~ 'o~her' inhibition agent.
The use of a hydroxide as the sole inhibition agent is limited bS,~ ils ~bili~y to reducc ~he degree of polymerisa"ion ~.rithln the soluticr,. The preferred amount of the hvdroxide is 1 ~O 20% by ~eight (base~ on ~he ~otal weight of the hydroxide (e.g. alkali Inetal hydro.~idel and silicate). more preferably 2 to lZ~6 on the same basis.
Solu~ions in accordanee wi~h the invention may be produced in wide ran~e of concentr3tions. It will ho~ever generally be n~ost convenient initially to f ormulate more concentrated solution5 f or tr~nspor~ to the site at ~hich the solution is to be used ant then to dllu~e the "eoneentrate" do~n to the required l~se s~rength. If ~he inhibi~ing agent is a carbonate or hydroxide then such a concentraee may conYeniently be prepared by mixing a commercial ~rade of silicate solution (which would generally co~tain 35% ~o 55% by weight solidsl wi~h a solution cf ~ppropriate s~rength of the ear~onate or hydroxide. .-If hovever rhe inhibiting agent is a p~osphate. it may be more convenient to di~ute a commercial silicate solulion ~o give a solld~
con~en~ o~ 15-40~; (e8 20-259~) by weignt before admi~ture wi~h a - CA 022l0873 l997-07-l8 P.10 17 J,UL '97._15,~0~ 5 . PCTIGB9C~O
. . ~ 5 solut~on of the phosphate since it may be tifficult to obtain the solution of the phosphate ~ higher silicate concentrations.
It is also possible to provide a t~o component fiyStem comprising (i) a cor~cer~t~at~d silicate solution, and (ii) an inhibiting agent soluticn. the two solutions being mixed on sile prior to use.
Alkali metal silica~e solutions in accordance with the invention are parlicula~ly suitable ~or use in oil indus~ry applicat~on~, As such, the ~olut~ons may be for~lated into drillin~ flu~ds (including d~illin~
muds clear dr~lling fluids, workover fl~ids~ and oil ~rell workin~
ids~. Such fluids may compri~e up to 259~ bv weight, more usuaily 5-10~ by weight, of alkali metal silicate. The flu~ds may~ for example.
be used in shale st~ tion pro~es es.
The in~,rention will be illustrated by ~eterence to the followirlg non-limi~ed ~Sxamples.
Example ~
A ~ilic~te solution (dssi~nated ~ample 1) in accor~ance with ~he invent~on wa~ prepared by r~liY;rlg O,z g 50% w!W potass~um hyd~oxide solution and 1 g tetrapo~assium pyrop~ospha~e in 88.8 ~ de~ion~set wate~, Ar~ g lt~ ~ of Q79 sodium silicate sol~tion ~a-ailable ex Brunner Mond) ~nd stirring for 2 minutes. Q~9 has a SiOz:NazO weight ratio of 3.~ and a ~il;cate sol;ds content o~ 3~.1% by weight.
The tolerance of th~ solution to precipi~ation and/or gelation of the silicate ~as determined ~y t~rat~ng ~he solution with synthetic seawa~er whi~st measuring the ~u2~bidi~y of the solution by li8ht tran~mi ~sio~. The end poin~ ~a~ determined by the point at which li~ht dispersion cA~ses a d~op in t~ansmi~et light iue to the inte~ention cf particulate matter. The ~yn~he~ic seawater used in this procedure had the composition shown i:l the Hand'oook o~
ctry and Physics, 58th Edition, F-203 sa~re ~hat components having a concent~ation less than 100 ppm were excludet.
The result iB shown in Table 3.
A further sample (Sample 2) ir~ accosdance with ~he l~ention was prepared by the fiame procedure but usin~ 0.2 g 50% ~/w ~otasslum hydroxide solution, 2 ~ tetrapotassium pyrophosphate, 87.8 g ~IPio~ised water and 10 g of Q79 sodium silicate solution. The tolerance to preeipit~tion and/or gelation was measured~ as p~eviously.
-CA 02210873 1997-07-18 P.ll 17 JUL ~97_ 15,0*c PCr/GB96roOl2C
.
.l ,urlher sample ~Sample 3) cont~i~ing potas~ium hydroxide (in the amc,n; sho~rn ~n ~able 3: but no tetrapotassi~m pyrophosphate ~ras also pre?areo and the tolerance measured as previously.
B~ way of comparison, Sample 4 ~hich contained ne~ ther potassium nydroxide nor ~e~rapotassium pyrophosphate was prepared and its ;oIerance also measured.
~ oe results are snown in Table 3.
' . W0 9U~22~S CA 0 2 210 8 7 3 19 9; - O 7 - 1 B P . lZ
L ~;
a ~
c2. r cr~ ~r . ~ tJ ", ' .
0 ~ E
~1 ~ 0 .,~ ~ ' .
r~ S
I ~
O O ~ O o ~0 L O O , ~J 4 _~
,, .
. ; : .
, X
h .
E ~1 .,. ~. . .
~ ~ o o o o ~~ o ~ .
.
~1 ~
rJ ~O O o ~ ~
.,, _ U ~ ,_ ., 4 E
h r.~
CA 022l0873 l997-07-l8 P.13 17 JUL '97 1~-,0 ~
.
B
1~ can be seen from Tabie 3 that all of Sa,mples 1 to 3 show superior tolerance to precipitzlion~gelation than Sample 4 which d~d not con~ain an inhibition agen~. The result ~as best for Samp}e 2.
l~xam~le Z
A sil.cate solution ~a5 prepared by t3king 1 g 50% ~~/w potassium c~oxite ~nd 10 ~ ;n~ telrasot.um pyrophospha~e with 30 g deior~eed waler. adding So g Q79 sodi~m siilcate and stirring for Z minutes.
A 2~ ~ aliquo~ Or ~he solu~ion ~as made ~Ip to 100 g wit~ deioniset ~~ater and ~ested for its tolerance ~o sea waeer ag described in Example 1 ~bove. The result was s-~bs~an~ially th~ same as for sample 1 ~Examp1e 1 ) above.
Exam~l- 3 Using a sodium 5ilicate soiution ha~ g a solids content o~ 53.5%
and a SiO2:::a~0 ~eight ra:io of 2, Samples g and 5 ko~r~rative) having the composition sho-~n in Table 4 wer~ prepared. The sàmples were tes~ed for ~heir tolerance to sea-/ater as de~cribet in Example 1 abo~.~e.
The resul~s are shown in TAble 4 and once again the supe~ior result obtained b~ the p~esence OI po~assiu~ hydroxide and ~etrapot~ssium pyrophosp~.ate (as compareA ~o r.o inhibi~ing a-gent al all) are clearly temonc~rated.
CA 022l0873 l997-07-l8 P.14 17 JUL ' 97, . _15 :,05"~5 . BCT/GB9~UOO~
, O ,~.~
r C
~U
Ul ~
:~ U
O ~ E O --e ~
.u ~ C4 o o ~0 . oo n ~ o . . ..
_, ~
~, .p E
.~ ~ .
Dl ' O O
O
o _ a ~
~ ~ .
.. ~ .
r 8 t" o '- ~ O o ~ ~1 Ir 01 .
_l C
E
U~ Ul ~o
Claims (20)
1. An alkali metal silicate solution containing an inhibition agent effective to inhibit precipitation or gelation of said silicate in the solutions in the presence of divalent metal ions wherein said agent is a pyrophosphate of a univalent cation.
2. A solution as claimed in claim 1 wherein the amount of silicate solids in the solution comprise 30 to 99% by weight of the total weight of the silicate solids and pyrophosphate.
3. A solution as claimed in claim 1 or 2 wherein the alkali metal silicate comprises sodium silicate.
4. A solution as claimed in claim 3 wherein the sodium silicate has a SiO2:Na3Oratio of 1.6.1 to 3.6.1.
5. A solution as claimed in any one of claim 1 to 4 wherein the alkali metal silicate solids comprise 30 to 99% by weight of the total weight of the alkali metal silicate solids and pyrophosphate which will correspondingly be 1 to 70% by weight on the same basis.
6. A solution as claimed in claim 5 wherein the alkali metal silicate solids comprise 50 to 99% by weight of the total weight of the alkali metal silicate solids and pyrophosphate which will correspondingly be 1 to 50% by weight on the same basis.
7. A solution as claimed in claim 1 wherein the pyrophosphate is present in an amount of 15 to 55% by weight based o the total weight of the silicate and pyrophosphate.
8. A solution as claimed in claim 7 wherein the silicate is sodium silicate having a SiO2:Na2O weight ration of 1.6 to 2.1 and the pyrophosphate is present in an amount of 15 to 30% by weight base on the total weight of the silicate and pyrophosphate.
9. A solution as claimed in claim 7 wherein the silicate is sodium silicate having a SiO2:Na2O weight ration of 2.1 to 2.6 and the pyrophosphate is present in an amount of 20 to 45% by weight based on the total weight of the silicate and pyrophosphate.
10. A solution as claimed in claim 7 wherein the silicate is sodium silicate having a SiO2:Na2O weight ration of 2.6 to 3.6 and the pyrophosphate is present in an amount of 35 to 55% by weight based on the total weight of the silicate and pyrophosphate.
11. A composition as claimed in claim 1 wherein the solution further comprises a hydroxide in an amount up to 10% by weight of the total weight of the pyrophosphate, hydroxide and silicate and the amount of the pyrophosphate is 15% to 60% on the same basis.
12. A solution as claimed in claim 11 wherein the silicate is sodium silicate having a SiO2:Na2O weight ration of 1.6 to 2.1 and the solution contain 1 to 10% by weight of the hydroxide based on the total weight of the pyrophosphate, silicate and hydroxide and 15 to 35% by weight of the pyrophosphate on the same basis.
13. A solution as claimed in claim 11 wherein the silicate is sodium silicate having SiO2:Na2O weight ration of 2.1 to 2.6 and the solution contain 1 to 10% by weight of the hydroxide based on the total weight of the silicate, pyrophosphate and hydroxide and 20 to 40% by weight of the pyrophosphate on the same basis.
14. A solution as claimed in claim 11 wherein the silicate is sodium silicate having a SiO2:Na2O weight ration of 2.6 to 3.6 and the solution contain 1 to 10% by weight of the hydroxide based on the total weight of the silicate, hydroxide and pyrophosphate and 40 to 60% by weight of the pyrophosphate on the same basis.
15. A solution as claimed in any one of claims 11 to 14 wherein the hydroxide is potassium hydroxide.
16. A solution as claimed in any one of claims 1 to 14 wherein the pyrophosphate is potassium pyrophosphate.
17. A solution as claimed in any one of claim 1 to 16 further comprising a carbonate.
18. A drilling fluid comprising a solution as claimed in any one of claims 1 to 17.
19. A drilling fluid as claimed in claim 18 which comprised up to 25% by weightof the alkali metal silicate.
20. A drilling fluid as claimed in claim 19 comprising 5 to 10% by weight of the alkali metal silicate.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GBGB9501099.7A GB9501099D0 (en) | 1995-01-20 | 1995-01-20 | Silicate solutions |
| GB9501099.7 | 1995-01-20 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2210873A1 true CA2210873A1 (en) | 1996-07-25 |
Family
ID=10768297
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2210873 Abandoned CA2210873A1 (en) | 1995-01-20 | 1996-01-22 | Silicate solutions |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0804383A1 (en) |
| AU (1) | AU4454596A (en) |
| CA (1) | CA2210873A1 (en) |
| GB (1) | GB9501099D0 (en) |
| NO (1) | NO973334L (en) |
| WO (1) | WO1996022245A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105439160A (en) * | 2015-11-29 | 2016-03-30 | 洛阳绿仁环保设备有限公司 | Method for preparing potassium silicate from potassium feldspar |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0770661A1 (en) * | 1995-10-27 | 1997-05-02 | B W Mud Limited | Lubricant for drilling mud |
| EP1780185A1 (en) * | 2005-10-25 | 2007-05-02 | Services Pétroliers Schlumberger | Versatile additives for well cementing applications |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2387694A (en) * | 1936-03-27 | 1945-10-23 | Truman B Wayne | Treatment of drilling fluids |
| US2304232A (en) * | 1936-06-06 | 1942-12-08 | Nat Lead Co | Method and means for controlling drilling muds |
| US2377309A (en) * | 1944-02-14 | 1945-06-05 | Tide Water Associated Oil Comp | Drilling mud |
| JPS5849585B2 (en) * | 1978-07-10 | 1983-11-05 | 日本化学工業株式会社 | soil stabilization method |
| JPS5575481A (en) * | 1978-12-01 | 1980-06-06 | Ohbayashigumi Ltd | Soil stabilizer |
| US4391643A (en) * | 1981-05-21 | 1983-07-05 | Halliburton Company | Rapidly dissolvable silicates and methods of using the same |
| DE3669871D1 (en) * | 1986-02-05 | 1990-05-03 | Henkel Kgaa | AGENT BASED ON MODIFIED ALKALINE METAL SILICATE SOLUTIONS FOR SEALING AND / OR STRENGTHENING AND / OR BINDING. |
-
1995
- 1995-01-20 GB GBGB9501099.7A patent/GB9501099D0/en active Pending
-
1996
- 1996-01-22 WO PCT/GB1996/000126 patent/WO1996022245A1/en not_active Application Discontinuation
- 1996-01-22 EP EP96900640A patent/EP0804383A1/en not_active Withdrawn
- 1996-01-22 CA CA 2210873 patent/CA2210873A1/en not_active Abandoned
- 1996-01-22 AU AU44545/96A patent/AU4454596A/en not_active Abandoned
-
1997
- 1997-07-18 NO NO973334A patent/NO973334L/en unknown
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105439160A (en) * | 2015-11-29 | 2016-03-30 | 洛阳绿仁环保设备有限公司 | Method for preparing potassium silicate from potassium feldspar |
Also Published As
| Publication number | Publication date |
|---|---|
| EP0804383A1 (en) | 1997-11-05 |
| AU4454596A (en) | 1996-08-07 |
| NO973334D0 (en) | 1997-07-18 |
| NO973334L (en) | 1997-09-08 |
| WO1996022245A1 (en) | 1996-07-25 |
| GB9501099D0 (en) | 1995-03-08 |
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