STABLE LIQUID SUSPENSION COMPOSITIONS AND METHOD OF MAKING AND USE THEREOF

Abstract: A new stable liquid suspension containing non-soluble particles dispersed in a non-aqueous liquid medium having a concentration of a suspension aid and a method of making and use thereof.

Description: STABLE UXD SUSPENSION COMFGSϊftάNit A !! MAKING AND USE THKfUfiO* This invention relates to novel liquid suspension compositions, h ch can be used as additives in a water-based fluids, and mctαods of making an | use of such liquid suspension compositions. Background of the Invention Water-based fluids suc as, for example, drilling fluids and miting fluids, are useful in a variety of industrial, applications, Tt is well known. to " bose aldlled in the art of drilling wells to tap subterranean deposits of natural res jurccs such as gas, gcothcrmal steam or crude- oil, especially when drilling by the rolary method or the percussion method wherein cuttings must be rer loved frura the bore bole, that it is necessary tς< use a drilling fluid. The use of water-based fluids in stimulation, orkover and completion fluids in oil field operations is also woll knuwu. Workover fluids Additives, chemicals, or other materials are often added to such Wδjcei'-bascd fluids for various reasons such as for controlling water loss, iαc reasing viscosity, reducing corrosion, altering pH, and increasing density of fluids. However, the addition of such materials to water-based fluids uui be dif ϊcult unless proper precautions are taken to pnjclude agglomeration or pivjgging. Liquid additives and processes therefor have been developed to overcome some of the problems. However, the hydrocarbons and other co] npounds used as the liquid medium of such stable liquid additive su; pensions may uor be environmentally friendly: because, fhcy arc often not bic degradable or because their use in drilling and well treatment fluids may resjult in noncompliance with EPA oil and greas efflueiii linύlalions. It is, Therefore, highly desirable TO develop a liquid suspension composition which remains stable, useable as an :ιdditi ve in water or water- ba: ;ed fluids, and which is environmentally friendly for use in oil field ap; plications. Summary o the Invention It is thus an object of this invention to provide a stable liquid suspension wmpusifion which is environmentally friendly and useful in oil fiej-d applications. Other aspects., objects, and the several advantages ofthe indention will become more apparent in light ofthe following disclosure. According to a first embodiment of the invention, a stable liquid no j x-aqueouε liquid suspension is provided. The non-aqueous suspension corjrposlrion comprises non-soluble panicles that arc dispersed in a non- aqi eons liquid medium. The nnn-aqueous medium has a cσncenualiou of a sus wpsion aid. The non-aqueous liquid medium is selected from the group cot sisting of glycols, polyglycols, glycol ethers, glycol esrers and glycol ether est :rs. The suspension aid is selected from the group consisting of hy< roxypropyl cellulose, ethyl cellulose, polyvinyl pyrrolidone, polyacrylic aci 1, and copolymers of polyvinyl pyrrolidone aαd acrylic acid. Iu a second embodiment ofthe invention, a non-aqueous sus pension is prepared by mixing non-soluble piulicles, a suspension aid, and a liq lid medium to therehy form the non-aqueous suspension. The liquid me iiura is selected from the group consisting of glycols, polyglycols, glycol etψrs, glycol esters and glycol ether esters. According to a third embodiment ofthe invention, a method is prdvidcd for treating oil or gas wells or any of the surrounding subterranean foi nations adjacent to such oil or gas wells. This method comprises the sseps of idπiixing with a water-based fluid a composition comprising non-soluble a] tides dispersed in a non-aqueous liquid medium having a concentration of a su< pension aid. The non-aqueous liquid medium is selected from the group consisting of glycols, polyglycols, glycol ethers, glycol esters and glycol ether εstϊrs. The suspension aid is selected from the group consisting of hy Iroxypropyl ceHulose, ethyl cellulose, polyvinyl pyrrolidone, polyacrylic acijl, and copolymers of poly vinyl pyrrolidone aαd acrylic acid. The thus- forrned aά^nlxture is introduced into a wcllborc. Detailed Description of th Invention In accordance with the present invention, the novel nnn-aqueous As referred to herein, the term "non-aqueous" means, unless otherwise indicated, a liquid that contains a minor amount of water, but, pr fcrably, the liquid is one that is substantially free of water. The minor am Dunt of water in the non-aqueous suspension medium is a concentration of wa er dial is low enough to assure that the invcnri. vc non-aqueous suspension ma inta s the fluid properties of a stable suspetiidon. A minor amount of water is i :enerally less than about ten weight percent (30%) ofthe non-aqueous liquid me fium. Thus, a minor amount of water will be in the range upwardly to about ten weight percent (10%). As noted, ι'τ is preferred for the non-aqueous liquid of he invention xo be substantiaUy free of water Therefore, the non-aqueous liqj id medium of the invention can have less than about oue weight percent (I (i) water, preferably, the amount of water is less than about 0.5 weight pe ent, and, most preferably, the amount of water is less than 1000 parts per million by weight (ppmw). An important aspect of this invention is for the non-aqueous H iid medium to be an environmentally friendly compound. That is, a sd ϊo e from the group consisting of glycols, polyglycols, glycol ethers, glycol esφrs and glycol ether esters. Each glycol or polygiycol compound suitable tor use as the non- aqteous liquid medium o the invention should have a molecular weight greater fh∑ n about 100; because, those compounds that have molecular weights below ab( mt 100 tend to undesirably solvate the suspended particles. However, due to tht requirement tiiat the uon-aqueous liquid medium be in the liquid phase at air, bienx temperatures, its molecular weight should be less than about 4,000. Th ϋrefore, suitable glycols and polyglycols can hive a molecular weight in the r ar ge of from about 100 to about 4,000, preferably from about 100 to about 3,0)00, and more preferably, from about lϋϋ to 2,750. The glycols that can be used as the αon-aqueous medium have the following general formula: ΪI-0-R,-0-H wbjere R t is an alkyl group having from 4 to 8 carbon atoms, preferably, from 3 to 1- carbon atoms. Examples uf suitable glycols; include butylene glycol, 1,5- peijitanediol and hexylene glycol. The polyglycols that can be used as the non-aqueous medium hafe the following formula: H - (O-R^ O-H wt are R, is an alkyl group having from I to 6 caruuu atom , preferably, from 2 to • 1 carbon atoms. Specific examples of polygiyc-ols that can suitably be used mc hide, but are nor. limited to, diethylene glycol, uiethylene glycol, dij ropylene glycol, tripropylene glycol, polyethylene glycol (having a mc lecular weight between 200 to 4,000), and polypropylene glycol (having a mc lecular weight between 200 to 4,000). The presently preferred polyglycols for use as the non-aqueous medium arc diethylene glycol, tricthylcnc glycol and polypropylene glycol. Polypropylene glycol is particularly preferred because of its commercial availability and effectiveness. 10 The glycol ethers that can be used as the non-aqueous medium ha e the following general formula: R 2 LO- J, ϋ- , whbre R, is an alkyl group having from I to 6 carbon ato s, preferably, from 2 to • I carbon atoms, and where each R 2 can be the me or different and further 15 wh src ^ is cither a hydrogen or an alkyl group having from 1 to 10 carbon ate Q S, preferably, from 1 to 4 carbon atoms. The value for π is an integer in the rar, ge of from 1 to 10. Specific examples of glycol ethers which can suitably be use d as the non-aqueous medium include, but are not limited to, 2- Bu axyethanol, 2-(2-Butoxyethoxy) ethanol, di ropylene glycol) methyl ether, 7.0 riier ylene glycol dimethyl ether, diethylene glycol ethyl ether, and diethylene gl col butyl ether. The presently preferred glycol ethers for use as the non- aqieous liquid medium ofthe novel suspension composition arc diethylene gl> col ethyl ether and diethylene glycol butyl ether. The most preferred glycol e rjer is diethylene glycol butyl ether. The glycol esters that can be used the non-aqueous medium ha e the following general formula: R, [R O] n R 3 wfcjare j is a carboxyl group having from 1 to 6 c rbon atoms, preferably, from 1 J 4 carbon atoms, and where R 2 is an alkyl group having from 1 to 6 carbon ate ras, preferably, from 1 to 4 carbon atoms, and where R 3 is cither a hydrogen or i carboxyl group having from 1 to 6 carbon atoms, preferably, from 1 to 4 cat Don atoms. The value for „ is an integer in the range of from 1 to 10, Sp :cific examples of glycol ester compounds that can suitably be used as me noi i-amienus liquid medium include, but are not limited to, 1 ,2-Kfhaneriiol mcjαoacetate snά ethylene glycol diacetaτe. Examples of glycol ether ester compounds that can suitably be usdd as the non aqueous medium include, but are not limited to, 2 ethoxy ethyl ace tatc, di(cthylcnc glycol) ethyl ether acetate, di( ethylene glycol) butyl ether acejtaxe and di(ρroρylene glycol) methyl ether acetate. It is an important aspect of the present invention for the suspended particles ofthe non-aqueous suspension to be substantially non- sol able, or only partially soluble, in the non-aqueous l quid medium But, they ah must form a relatively stable suspension when mixed in such medium. Th as, the non-soluble particles arc solid particulates Utat arc substantially k luble, or partially soluble, hi the non-aqueous liquid medium. When referring herein to the stability of a liquid suspension, it is unjierstood that a stable liquid suspension is defined as a liquid suspension in wf. ich the non-soluble particles remain dispersed in the liquid phase and do not set le out and separate from the liquid phase after a substantial period time has paf sed. Generally, such time period exceeds 3 days (i.e. 72 hours), but re ferably, the non-soluble particles should remain dispersed in the h ' quid phi sc, or non-aqueous liquid medium, for a period of time exceeding 5 days (It . 120 hours) and, most preferably, the particles should remain dispersed in die liquid phase, or aon-aqueous liquid medium, lor a period of time exceeding 10 lays (i.e. 240 hours). The non-soluble particles ofthe inventive composition should iht nuu-aqueuus Uquid medium lo form a stable solution when combined with thtj other components ofthe suspension composition. Examples of materials suitable for use as non-soluble particles of Another important component of fhι$ non-aqueous suspension is the] suspension aid used to provide additional viscosity to the liquid medium so as ■ o assist in keeping the non-soluble particulatc material dispersed in the liqi iid medium. It is essential that the properties ofthe suspension aid be such tlia : ic is soluble, or at least partially soluble, in The non-aqueous Uquid medium of i he inventive composition while at the same time enhancing the sus pendabiliry o the non-soluble particles within the liquid phase of the. cor rposirinn and, thus, The stability of the inventive composition. It has been fox ad that small concentrations of he compounds of hydroxylpropylcellulose (H ?C), ethyl cellulose, polyvinyl pyrrolidone, polyacrylic acid, or copolymers of aolyvinyl pyrrolidone and acrylic acid assist in significantly enhancing the sla ή lily ofthe non-aqueous suspension. Thus, Jtn essential feature ofthe inventive composition is for the non-aqueous liquid medium to contain a concentration of either hydroxypropyl cellulose, qir ethyl cellulose, or polyvmyl pyj rolidone, or polyacrylic acid, or a copolymer of polyvinyl pyrrolidone and acr /lie acid in such an amount that it is sufficient to enhance the stability ofthe su∑ pension ofthe non-soluble particles in the non-aqueous liquid medium of die inventive composition. The preferred suspension aid is hydroxypropyl ccl ulosc. Based on the total weight o the non-aqueous liquid suspension corhposition of the present invention, the suspended non-soluble particles in the ton I suspension composition solution can be present in any weight percent pro tfided the suspension is stable. Generally, however, the weight percent of sus tended particles in the total suspension composition can be in the range fto: n about 10 weight percent to about 70 weight percent, preferably, from abc at 20 weight percent to about 60 weight percent and, most preferably, from 30 -jvcight percent to 50 weight percent. As for die concenttation of the suspension aid in the non-aqueous sus .tension composition, it must be present in the non-aqueous liquid medium in bn amount and at a concentration sufficient to provide the necessary function of enhancing the stability ofthe suspended particles in the Uquid phase o the su: pension coiupυsilrui It has been found that a concentration as a percentage of he total weight ofthe non-aqueous suspension composition of at least 0.1 we ight percent is required to provide the necessary suspension aid function. Th ϊ upper limit for concentration o the susρensic>n aid is dictated by the maximum thickness o the non-aqueous suspension composition that may prs ctically be handled. It has been found that the maximum concentration of the suspension aid in the non-aqueous suspension composition should not cxc ccd about 0.9 percent of he total weight of suυh composition. Thus, the coi centratiou range for the suspension aid in the non-aqueous suspension co position can be in the range of from about 0.1 weight percent to about 0.9 we ghi percent. Preferably, the concentration range for the suspension aid shcjuld range from about 0.125 weight percent to about 0.7 weight percent and, mott preferably, the concentration ofthe suspension aid should range from 0.15 we: ght percent to 0.35 weight percent, The non-aqueous liquid medium component ofthe non-aqueous suspension composition will generally make up the remaining portion ofthe nor -aqueous suspension composition with a typical range of from about 30 wei i percent to about 90 weight percent o the liquid suspension, preferably ftoi i about 40 weight percent to about 80 weight percent, and, most preferably, fit m 50 to 70 weight percent ofthe total weight ofthe non-aqueous suspension oojnpositton. The following Table 1 sturi arhics the ranges ofthe components of |the inventive non-aqueous suspension composition ofthe invention. TABLE T Typical Ranges For the Components of the; Stable Liquid Suspension Broad Most Cclmponent Rang Range Preferred Ranee Ncn-Soluble Particles 10-70% 20-60% 30-50% Su spension Aid 0.1-0.9% 0.125 0.7% 0.15-0.35% Ncjn-Aqueous Liquid Medium 30-90% 40-80% 50-70% The inventive non-aqueous liquid suspension can be prepared by any suitable method known in the art. The components of the inventive COJ πposiiiυn may be mixed together in any order or altogether at the same time; bo' vever, it is preferred for the suspension aid to be first dissolved or mixed wii h the non-aqueous liquid medium prior to the addition ofthe non-soluble paψicles to the thus-formed liquid mixture. Conditions for mixing or dissolving the suspension aid in the noil aqueous liquid medium are not α critical aspect ofthe invention and aπ.5 one skilled in the art may use conventional trøhniques for forming the sol ition. Generally, the temperature range for mixing the suspension aid in the noij -aqueous liquid medium shall be hi the range of from about 5°C to about 15b°C, but the preferred temperature range is from about 10°C to about 100°C anji a most preferred temperature range is from about 20°C to about G0°C. Any standard mixing device that provides reasonably high sheer lo kssisi in forming the solution of non-aqueous liquid medium and suspension aid can be used. The mixing lime is that which is. necessary to provide the cle τable so] ution such that the suspension aid is dissolved in the non-aqueous liquid majdium. Such mixing time is generally in the nuige of from about 0.01 hours to xbout 200 hours. Once the solution of non-aqueous liquid medium and suspension aid is formed, the non-soluble particles arc admixed to the Ihus-furmcd solution in ;uch au amount as lo provide the desirable concentration of non-soluble pai tides within the final non-aqueous liquid suspension composition. The novel, non-aqueous liquid suspension described hereinabove is particularly suitable for use as an additive to water-based oil and gas oil well u * e: itment fluids. Such well treatment fluids include, for example, stimulation flu dε, fracture fluids, drilling fluids, completion iluids, and workover fluids. Ty jically, an oil or gas well will penetrate the surface of the earth and pass tlir gh various subterranean formations that contain deposits of natural res )urccs such as oil and gas. Additives to the water-based fluid used either to drijl or to treat wellbores or sunoαnduig subterranean formations are used to rci tucc the amount of well treatment fluid that is lost to the surrounding fo: mations oτ to enhance the carrying capacity or viscosity of such well ire aimeiu fluids. Thus, because of the particular properties ofthe inventive no i-aqueous suspension described herein, it can .suitably be used as an additive to 3il and gas well treatment fluids by admixing with a water-based fluid in sn ;h manner as to form an admixture. This adr xture can be introduced into a wellbore thereby The product of this invention is pnmarily tested by observation of thc| liquid suspension for stability over a wide temperature range. Stability can be neasured by means of a ruler υr other such graduated device whereby there is deiermmed the thickness from the interface of me clear liquid portion of the pur uun of the liquid that separates from the portion ofthe liquid containing suspended solids. The following specific examples arc intended to illustrate lUc advantages of the present invention and are not intended to unduly limit the so >pe of the invention. EXAMPLE 1 This Example shows the stability o the novel non-soluble polymer suspension having the components of guar gum suspended in the cojnbined diethylene glycol butyl ether and hydroxypropyl cellulose. 700 grams of 0.4% hycfroxylpropylcellulose ( luccl H f oui Ildrcules, Inc.) solution was first prepared. The 2.8 grams of hydroxypropyl eel lulose was added to 697.2 grams of he di(ethylene glycol) butyl ether ("I ) BE") (Aldrich), heated to 175 degrees F and stirred for four hours using a ρa< idle type mixer. Once the hydroxypropyl cellulose was fully dissolved, po: tions of this solution were separated and diluted with di(ethylene glycol) bu yl ether to yield the various other desired hydroxypropyl cellulose coi -centrations (Table 1). To each of these base fluids was added sufficient gi r gum (Progum from PolyPro Inc., Dalton, G A) to produce a 40% w/w sus pension of particles (Table 1). The viscosity of each suspension was dct ϊrmined using a Brookfield DV2 Yiscometer with a #3 LV disk spindle. The sus ensions were finally placed into glass jars and observed for stability. Set .ling was evidenced by the separation of clear fluid to the surface ofthe su sponsion. The settling time, or the time required for the onset of fluid separation was recorded and is a measure ofthe suspension stability. TABL 2 Weight of Each Comoonenrfg1_ Concentrations f/A. luc H DBE Guar Klucel H Dioxitol Gua r Co upositiou A 0 200 133.3 0 60 40 Co nposi ion B 0.40 190.6 133.3 0.12 59.88 40 Co nposition C OM 1.09.4 133.3 0.18 59.82 40 Co nposiuon D 0.72 179.3 120.0 0.24 S9.76 40 Settling Suspension Viscosity fcanTi oisg) Time (flrs) β.φm CobpositionA 5<J0 0.1 Co nposit m B 24 0 I Co nposiπon c XfiOO 16 Co npositionD 21800 >360 With no hydroxypropyl cellulose {is a suspending agent, the guar gujn panicles began settling out of suspension almost immediately. With the a < ϋrion ofthe suspending agent, the settling time was delayed. At a coi icentrarion of only ϋ.24%, the hydroxypropyl cellulose prevented particle set ling for more than 360 hours. EXAMPLE S This example demonstrates the long term stability of particle sus cnsioiis made with the hydroxypropyl cellulose in a di(ethylene glycol) but/1 ether. In this test, 2.25 grams of hydroxypropyl cellulose (Klucel H fr< Hercules Inc.) was blended into 222.60 grams of di(cthylcnc glycol) butyl etl ter to produce a 1% polymer solution. After Λϋvc days, although the so ution was very viscous, there were still numerous undissolved particles. SL LTicicui di(cibybne glycol) butyl ether was added to dilute the polymer to a oo i entration of 0.5% and the solution was heaied to 180 degrees F and stirred fo: one hour. After cooling, a xanthan biopnlynw (Flowzan® from Drilling Sp ?.cialties Company) was added to produce a 40% w/w suspension of pa ticles. In this example, 6% water was also added in order to reduce the dejiεity ofthe suspended particles. 10 The viscosity of this suspension was measured using a roo field 1.5 ohferved, indicating exceptional stability in the .•suspension. The results shown in the above examples clearly demonstrate that the] present invention is well adapted to carry out the objects and obtain the end an< advantages mentioned as well as those inherent therein. While mc ificαtions may be made by those skilled in tiκι art such modifications are cu ompasscd within the spirit of the present invention is defined by the specification and claims.

Claims: T^AT WHICH IS CLAIMED IS: 1. A non-aqueous suspension comprising; non-soluble particles dispersed in a non- aqueous liquid medium having a concentration of a suspension aid wherein said non-aqueous liquid medium is selected from the group consisting of glycols, polyglycols, glycol ethers, glycol esters, and glycol ether asters and wherein said suspension aid is selected from the group consisting of hydroxypropyl cellulose, ethyl cellulose, polyvinyl pyrrolidone, polyacrylic acid and copolymers of polyvinyl pyrrolidone and acrylic acid. 2. A non-aqueous suspension as recited in cl.iim 1 wherein said non- aqueous liquid medium is selected from the group consisting of diethylene glycol, triethylcne glycol, polypropylene glycol, diethylene glycol ethyl ether, and diethylene glycol butyl ether. 3. A non-aqueous suspension as recited in claim 2 wherein said concentration of said suspension aid is in the range of from about 0.1 to about 0.9 weight percent of the total weight o the non-aqueous suspension, and wherein the amount of said non-aqueous liquid medium in the non-aqueous susp erosion is in the ran gc of from about 30 weight percent to 90 weight percent of the total weight ofthe non-aqueous suspension. 4. A non-aqueous suspension as recited in claim 1 wherein said non- aqueous liquid medium is a pulyglycol. * 5. A non-aqueous suspension as recited in c;laim 4 wherein said concentration of said suspension aid is in ihe range of from about 0.1 to about 0.9 weight percent of e total weijrjn ofthe non-aqueous suspension, and wherein the amount of said non-aqueous hquid medium is the non-aqueous suspension is in the range of from about 30 weight percent to 90 weight percent ofthe total weight ofthe non-aqueous suspension. 6. A non-aqueous suspension as recited hi claim 1 wherein said non- soluble particles are polymeric viscosifiers. selected from the group consisting of xarahan, hydroxyethyl cellulose, carboxyl methyl cellulose, guar gum, starch, derivinVed guar and polyacrylami.de. 7. A non-aqueous suspension as recited in claim 6 wherein said concentration of said suspension aid is in the range of from about 0,1 to about 0.9 weight percent of the total weigjht ofthe non-aqueous suspension, and wherein the amount of Stdd non-aqueous liquid medium is the non-aqueous suspension is ui the range of from about 30 weight percent to 90 weight percent of the total weight o the non-aqueous suspension. 8. A stable liquid suspension comprising: a liquid phase comprising a Hquid medium selected from the group consisting of glycols, polyglycols, glyco) ethers, glycol esters and glycol ether esters; non-soluble particles; and a stabilizing amount of a suspension aid ufficient to enhance the suspension of said non-soluble polymer psαrticles in said liquid phase. 9. A stable liquid suspension as recited in claim 8 wherem said non- aqueous liquid medium is selected from the group consisting of diethylene glycol, tricthylcnc glycol, polypropylene glycol, diethylene glycol ethyl ether, and diethylene glycol butyl ether. 10 A stable hquid suspension as recited in claim 9 wherein said stabilizing amount of said suspension aid is a concentration in the range of from about 0.1 to about 0.9 weight percent ofthe total weight of the stable liquid suspension, and wherein the amount of said Uquid medium in the > non-aqueous suspension is in the range o f from about 30 weight percent to 90 weight percent ofthe total weight ofthe stable liquid suspension. 11 A stable liquid suspension as recited in claim 8 wherein said liquid medium is a polyglycol. 12 A stable liquid suspension as recited in claim 11 wherein said stabilizing amount of said suspension aid is a concentration in the range of from about 0.1 lo about 0.9 weight percent of ihe total weight of the stable liquid suspension, and wherem the amount of said liquid medium in tire non-aqueous suspension is in the range of fiO about 30 weight percerri to 90 weight percent ofthe total weight of the stable liquid suspension. J. A stable liquid suspension as recited in claim 8 wherein said non-soluble pa icles are polymeric viscosifiers selected from the group consisting of xanthan, hydroxyethyl cellulose, carboxyl methyl cellulose, guar gum, starch, derivitized guar and polyacrylamide. j A stable hquid suspension as recited in c taim 13 wherein said stabilizing amount of said suspension aid is a concentration in the range of from about 0.1 to about 0.9 weight percent ofthe total weight of the stable liquid suspension, and wherein the araouαi. of said liquid medium in the non-aqueous suspension is in the range of from about 30 weight percent, to 90 weight percent ofthe total weight o the stahle liquid suspension. \ A method of preparing a non-aqueous suspension, comprising the steps of: mixing non-soluble particles, a suspension aid, and a Hquid medium selected from the group consisting of glycols, polyglycols, glycol ethers, glycol esters and glycol ether esters to thereby form saidnon-aqucuus suspension. | A method as recited in claim 15 wherein said suspension aid is selected front the group consisting of hydroxypropyl cellulose, ethyl cellulose, polyvinyl pyrrolidone. polyacrylic acid ami cypolyraers of polyvinyl pyrrolidone and acrylic acid. % A method as recited in claim 16 wherein said suspension aid is present in said non-aqueous suspension at a con entration in the range of from about 0.1 to about 0.9 weight percent o the total weight of said non- aqueous suspension, and wherein said non-aqueous liquid medium is present in said non-aqueous suspension at a concentration in the range of from about 30 weight percent to 90 weight percent ofthe total weight of the non-aqueous suspension. 8j. A method as recited in claim 16 wherein said non-aqueous liquid medium is a polyglycol. l A method as recited m claim 18 wherein said suspension aid is present in said non-aqueous suspension at a conceαtration in the range of from about 0.1 to about 0.9 weight percent ofthe total weight of said non- aqueous suspension, and wherein said non-aqueous liquid medium is present in said non-aqueous suspension at a concentration in the range of from abuul 30 weight percent lo 90 weight perecul of the total weight of the non-aqueous suspension. 0| A method as recited in claim 16 wherein said non-soluble particles are polymeric viscosiϊiers selected from the ;poup consisting of xanthan, hydroxyethyl cellulose, carboxyl methyl cellulose, guar gum, starch, dcrivitizcd guar and polyacrylamido. A method as recited in claim 20 wherem said suspension aid is present in said non-aqueous suspension at a concentration in the range of from about 0.1 to about 0.5 weight percent ofthe total weight, of said non- aqueous suspension, and wherein said non-aqueous liquid medium is present in said non-aqueous suspension at a concentration in the range of from about 30 weight percent to 90 weight percent ofthe total weight of the non-aqueous suspension, A method as recited in claim 16 wherein said non-aqueous liquid medium is selected from the group consisting of dielhylcrαc glycol, tricthylcue glycol, polypropylene glycol, diethylene glycol ethyl ether, and diethylene glycol butyl ether. A method as recited in claim 22 wherein sard suspension aid is present in said non-aqueous suspension at a concentration in the range of from about 0.1 to about 0.9 weight percent ofthe total weight of said non- aqueous suspension, and wherein said non-aqueous Hquid medium is present in said non-aqueous suspension at a concentration in the range of from about 30 weight percent to 90 weight percent ofthe total weight of the non-aqueous suspension. A method of preparing a non-aqueous Hquid suspension, said method comprises the steps of: mixing jioii-soluble particles with a liquid medium and adding thereto a stabilizing amount of a suspension aid sufficient to enhance the suspension of said non-soluble particles in said hquid medium. | A method as recited in claim 24 wherein said suspension aid is selected from the group consisting of hydroxypropyl cellulose, ethyl cellulose, polyvinyl pyrroHdone, polyacrylic acid and copolymers of polyvinyl pyrrolidone and acrylic acid. | A method as recited in claim 25 wherein said suspension aid is present in said non-aqueous suspension at a conccnuation in the range of from about 0.1 to about 0.9 weight percent of ihe total weight of said non- aqueous suspension, and wherein said non-aqueous liquid medium is present in said nnn-aquenus suspension at a concentration in the range of from about 30 weight percent to 90 weight percent ofthe total weight of the non-aqueous suspension. 1 A method as recited in claim 25 wherein snid non-aqueous liquid medium is a polyglycol. | A method as recited in claim 27 wherein said suspension aid is present in said non-aqueous suspension at a conccnu.ition in the range of from about 0.1 to about 0.9 weight percent of he total weight of Said uori- aqueous suspension, and wherein said non-aqueous Hquid medium is present in said non-aqueous suspension at a concentration in the range of from about 30 weight percent to 90 weight percent ofthe total weight of the non-aqueous suspension. | A method as recited in claim 25 wherein said non-soluble particles are polymeric viscosifiers selected from the group consisting of xanthan, hydroxyethyl cellulose, carboxyl methyl cellulose, guar gum, starch, derivitized guar and polyacrylamide. | Λ method as recited in claim 29 wherein said suspension aid is present in said non-aqueous suspension at a concentration in the range of from about 0.1 to about 0.9 weight percent of (he total weight of said non- aqueous suspension, and whcrciu said non-aqueous liquid medium is present in said non-aqueous suspension at a concentration in the range of from about 30 weight percent to 90 weight percent ofthe total weight of the non-aqueous suspension. j A method as recited in claim 25 wherein said non-aqueous liquid medium is selected from the group consisting of diethylene glycol, triethylene glycol, polypropylene glycol, diethylene glycol ethyl ether and diethylene glycol butyl ether. J A method as recited in claim 31 wherein said suspension aid is present hi said non-aqueous suspension at a concemr tion in th range of from about 0.1 to about 0.9 weight percent ofthe total weight of said non-aqueous suspension, and wherein sard non-aqueous liquid medium is present in said non-aqueous suspension at a concenttation in the range of from about 30 weight percent to 90 weight percent of the total weight ofthe non- aqueous .suspension. | A method of treating an oil or gas well or any surrounding subterranean formations adjacent thereto, said method comprises the steps of: admixing the composition of claim 1 with a water based fluid; and introducing the thus-formed admixture into a well bore, | A method of treating an oil or gas well ot ;uιy suriounduig subterranean formations adjacent thereto, said method comprises the steps of: admixing the composition of claim 8 with a water based fluid to form an admixture; and introducing said admixture into a well bore;. J A composition prepared by the method of claim 15. A composition prepared by the method of claim 24.

Inventors: FOX KELLY B, FOX, KELLY, B.
Applicants: CHEVRON PHILLIPS CHEMICAL CO, FOX KELLY B, CHEVRON PHILLIPS CHEMICAL COMPANY LP, FOX, KELLY, B.
Application year: 2001
Main classification: C09K7
IPC codes: C09K8