FI69860C - FOERFARANDE FOER TAETNING AV EN ZON KRING ETT GEOLOGISKT BORRHAOL GENOM ANVAENDNING AV EN CEMENTBLANDNING INNEHAOLLANDE ENETARDERINGSMEDELSKOMPOSITION - Google Patents

Description

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v '(51) Kv.lk. * / lnt.CI.4 C 09 K 7/02, CB 2A / 18, E 21 B 33/13 FINLAND —FINLAND (21) Patent application - Patentansöknlng 802639 (22) Application date - Ansökningsdag 21 .08.80 (Fl) (23) Starting date - Giltighetsdag 1 4.1 1. 78 (41) Has become public - Blivit offentlig 21.08.80

National Board of Patents and Registration Date of publication and publication. -

Patent- och registrstyrelsen '' Ansökan utlagd och utl.skriften publicerad 31 .12.85 (32) (33) (31) Privilege claimed - Begärd priority 09.02.78 USA (US) 876327 (71) American Can Company, American Lane, Greenwich, Connecticut 06830, USA (72) William John Detroit, Schofield, Wisconsin, USA [Jk) Berggren Oy Ab [Sk) Method for compacting the zone around a geological borehole using a cement mixture containing a retardant mixture La -Förfarande för tätning av en zon The present invention relates to a process for the determination of such a zone. The present invention relates to a process for the determination of such a zone. The present invention relates to a process for the determination of such a zone. for compaction around a borehole penetrating the geological underground by injecting a hydraulic cement mixture containing a retardant mixture for cementation purposes.

The underground geological formations, which are penetrated by boreholes for the production of petroleum and gas, have been at ever greater depths, with increasingly harsh conditions in the process, such as significantly higher temperatures. In addition, an increasing number of oil wells requiring cementation are also located at sea in saltwater environments, so that cementation mixtures must demonstrate compatibility with or tolerance to salt.

Cementing mixtures are used in particular to compact or cement the annular space in a borehole between the wellbore casing and the formation surrounding the casing. In practice, the cementation mixture is formed into a slurry, preferably, when the borehole at sea is cemented, 2,69860 of seawater to form the slurry. The slurry is pumped down through the borehole casing to form a geological formation and up along the outside of the casing to provide the required seal.

When more severe conditions are encountered, the need for improved additives to prevent premature curing of the cement slurry increases. In this case, the aim is in particular to eliminate the apparent hardening or gelation of the cement mixture and its retarding additives, in which state the cement reaches a viscosity which makes it difficult or impossible to pump it.

The issues related to borehole cementation and the methods used so far in this field are described in a report prepared by the Committee called The API Mid-Continent District Study Committee of Cementing Practices and Testing of Oil-Well Cements and published by the American Petroleum Institute ("API"). Division of Production, Dallas, Texas 75201 as API Bulletin D-4, revised edition, March 1963, entitled "The Effects of Drilling-Mud Additives On Oil-Well Cements"; "API Specification For Oil-Well Cements and Cement Additives", (API Std 10A, 14th edition, dated April 1969) and "API Recommended Practice For Testing Oil-Well Cements And Cement Additives" (API RP 10 B, 16th edition , dated April 1969).

Numerous lignin preparations have heretofore been proposed for use as retarders in borehole cementation mixtures and operations and are described, for example, in U.S. Patents 2,880,102, 2,491,832 and 4,065,318. These include alkali oxidized, hydrolyzed and partially desulfonated lignosulfates which have subsequently been resulfonated. which have been found to form effective, thermally stable, and predictable retarders that reduce or eliminate the undesirable gelation of many cement mixtures in many of the more severe environments to which they are exposed.

However, as earth and natural gas are being explored in increasingly harsh environments, further improvements in the predictability, thermal stability, and pseudo-cure resistance of borehole cement slurries are necessary; and if substantial improvements in these properties could be achieved while maintaining other properties such as salt resistance and compatibility with a large number of other components and cements, a significant advance in the situation in the industry would have been achieved.

The present invention therefore relates to a process for compacting a zone around a borehole penetrating a geological underground formation by injecting it for hydraulic purposes with a hydraulic semen mixture containing about 0.05-3% by weight of the resulting mixture of a retardant mixture consisting of lignosulfonates. an alkali metal derivative thereof obtained from a sulphite waste liquor which has been subjected to alkaline oxidation, hydrolysis and partial desulphonation followed by resulphonation, the process being characterized by reacting the resulphonated lignosulphonate with: (a) a halocarboxylic acid; (b) with a halocarboxylic acid and a hydroxy-substituted lactone; (c) with said hydroxy-substituted lactone; (d) a halocarboxylic acid followed by a derivative of a sugar-containing sulfite waste liquor obtained by the reaction of a sulfite waste liquor with cyanide followed by hydrolysis of the obtained reaction product, or (e) a derivative of said sugar-containing sulfite waste liquor.

According to the invention, it has been found that the use of novel lignosulfonate addition and double decomposition products and their alkali metal salts derived from sulfite waste liquor subjected to alkaline oxidation, hydrolysis and partial desulfonation followed by resulfonation and the above-mentioned reaction results in improved heat stabilization gel control and predictability and retardation of cement hardening.

69860

The lignosulfonates used in the process of the invention are derived from alkali oxidized, hydrolyzed, desulfonated and subsequently resulfonated 1ignosulfonates, wherein the resulfonated lignosulfonates are substituted with x 3 as X: it comprises sulfoalkyl groups of the formula - (CH-) SO-, H where y has a value of 1-3, and sulfo-

y * Y J

nyl radicals (-SO 2 H); and alkali metal salt derivatives thereof. The resulfonated lignosulfonate thus formed contains a total of about 1/2 to 15% by weight of sulfur in the Combined Organic Sulfonisulfonate Form, with the relative molecular size of the lignosulfonate prior to resulfonation being substantially 1000-20,000.

The reaction components mentioned in (a) to (e) above are preferably: (a) a halocarboxylic acid of the formula Mp (cnH2n ^ COOH, wherein M is a bromine or, preferably, a chlorine tower; p has a value of 1-3 and preferably 1 and n has a value of 1 to 7, for example 5-chlorocaproic acid, 3-bromobutyric acid, 2-chloropropionic acid, 4-bromocaprylic acid, trichloroacetic acid or, preferably, monochloroacetic acid or also the corresponding iodine and fluorine compounds; or a 3-lactone containing 4 to 5 carbon atoms and preferably a polyhydroxy-substituted lactone having the molecular formulas C 1 H 2 O 2;

CcHo0, - or mixtures thereof; bob b 1U b (c) the aforementioned lactone; (d) the aforementioned halocarboxylic acid and a derivative of a sulfite waste liquor containing sugar acid obtained by reacting a sulfite waste liquor with an alkali metal and preferably sodium cyanide to form cyanohydrin of the reducing sugars present, followed by hydrolysis of the obtained reaction product; and (e) the aforementioned sulfite waste liquor derivative.

The reaction of the resulfonated oxidized lignosulfates, described in more detail below and previously desulfonated, with a halocarboxylic acid is carried out in an aqueous alkaline medium, preferably having a pH of at least 8. The alkaline medium is provided with an ammonium, alkali metal or alkaline earth metal base or mixtures including, for example, carbonates, bicarbonates or, where appropriate for the cation used, amines. Sodium, lithium, potassium and calcium as well as, but less desirably, strontium and barium hydroxides are preferred. The reaction is desirably carried out at a temperature between 20-110 ° C and at ambient pressure for 2-6 hours; and most preferably at a temperature of about 80-100 ° C for about 5 hours. However, the parameters of time, temperature and pressure of 69860 are not very critical.

However, in a particularly preferred embodiment, the carboxyalkylated product (and most preferably the carboxymethylated derivative) prepared above is further reacted with one or more of the aforementioned hydroxy-substituted lactones and preferably gluconodeltalactone, said lactone amounting to 5-20% by weight and preferably n% to 5% by weight. the entire lignosulfonate-halocarboxylic acid reaction product to provide a further product believed to be an addition reaction product of the lactone and the previous stage condensation reaction product; a product which is surprisingly characterized by the ability to give hydraulic cements even more significantly improved temperature and pressure stability, predictability, salt resistance and gelation resistance combined with an extension of the period during which the cement hardens even at extremely high temperatures or 3,000. at greater depths. The lactone is easily fed into the reaction product mixture of lignosulfonate and halo-carboxylic acid.

Hydroxylated lactones are similarly reacted with lignosulfonate starting materials without intermediate reaction with a halocarboxylic acid in another embodiment, however, the product obtained, although better than the lignosulfonate starting material as cement retardant, is in any case less effective at ensuring high deceleration -lignosulfonate condensation product and significantly less effective than the acid condensation lactone reaction product.

Whether the lactone is re-added to the sulfonated lignosulfonate which has not reacted with the halocarboxylic acid or fed to the acid condensation reaction product mixture, the reaction is completed in a relatively short time of 0.5-1.5 hours and preferably about 0.5 hours and is preferably performed at ambient pressure in the range of 75-100 ° C and preferably between 80-85 ° C.

Although not intended to be limited to any theoretical consideration of this reaction process, it is believed that the lactones 69860 ··.: Yf '--- · react with the active hydrogen sites of the lignosulfonate reagent and in particular with the oxygen of the phenol group to form both bonds and simultaneously sulfone groups with lactone groups. believed to form esters.

As mentioned above, new and improved cement retardants are also prepared by reacting lignosulfonate starting materials or their halocarboxylic acid condensation reaction products with a sulfite waste liquor derivative obtained by reacting the reducing sugars present with cyanide to form cyanohydrin, and and even better by the reaction of cyanide in stoichiometric ratios based on glucose content for all reducing sugars present, such as in the use of Classical Killian-Fischer cyanohydrin synthesis. Considering the above cyanohydrin reaction, the sulfite waste liquor reagent used is first modified by the addition of a sufficient amount of reducing sugars to give a reducing sugar content of about 25% by weight. Of this sugar content, 18-20% preferably consists of pentoses and 20-25% hexoses. The series of reactions, which further reflects the use of Killian cyanohydrin synthesis, results in the hydrolysis of the resulting cyanohydrin to the corresponding sugar acid. This reaction results in the incorporation of additional carbon into each sugar molecule. Thus, a lignosulfate is obtained in which the reducing sugar pi-. a total of about 25% of its solids content is converted substantially to sugar acids with a total content of more than 25% and not more than about 32% by weight of the dry matter content of the lignosulfonate as its pentose and hexose content is converted to the corresponding weight concentrations of total sugar acid, i.e., about 18-20% of 6-membered sugar acids and 20-25% of 7-membered sugar acids. The hydrolysis is conveniently carried out by feeding the cyanohydrin to an alkaline aqueous solution having a pH of about 10 for about 1 hour at a temperature of 70-80 ° C under normal pressure according to the Killian synthesis above.

The latter concentration has been found to be particularly effective in providing the desired high temperature and high pressure resistant retardation additives. In fact, the ligno-sulfonate product obtained from the reaction with sulfite waste liquor, which in turn is derived from a series of cyanohydrin reactions, f: '·. 7 ';' ·· '· ·' · '' · '69860 wherein this sulphite waste liquor product, hereinafter referred to as KELIG 32 for convenience, contains concentrations of 7-membered sugar acid which are well above 20%, i.e. 20-75% or more of the total sugar acid content present, provides highly desirable cement retarders. These latter lignosulfonates are particularly useful when reacted with the reaction product of resulfonated, desulfonated lignosulfonates and a halocarboxylic acid, especially chloroacetic acid, which gives these cements an excellent thermal cement retarder.

Whether fed to resulfonated lignosulphate which has not reacted with the halocarboxylic acid or added to the acid condensation product mixture, the reaction is completed in a relatively short time of 0.5-1.5 hours and preferably in about 0.5 hours, as in the case of lactone addition and preferably at ambient pressure. about 50-100 ° C and preferably between 60-90 ° C. The hydrolysis of the resulting cyanohydrin is readily performed by standard methods.

In forming the reagent derivative for use herein, the sulfite waste liquor is that obtained from a standard acid sulfite cooking process, preferably using hardwood or softwood pulp. The sulfite waste liquor is preferably concentrated from a dilute solids content of about 14% obtained from the digester to a dry matter content of about 45%. This concentration is ensured by evaporation in a conventional sulfite waste liquor evaporator, e.g. a standard Triple Effect Rosenblad evaporator.

As mentioned above, the lignosulfonates used as reactive starting materials are derivatives of oxidized, partially de-sulfonated lignosulfonate obtained in oxidized waste liquor by oxidizing dilute vanillin in softwood or, although less favorably in deciduous sulfite waste liquor, by acidification prior to vanillin extraction. : o 2 491 832; and when the relatively uniform molecular size is ensured, the desulfonated lignosulfonate molecules are further treated with, for example, sodium bisulfite 11a and aldehyde, preferably '8 -' ·· 69860 formaldehyde at elevated temperature e.g. 160 ° C and pressure (1000 kPa) sulfoalky as described in U.S. Patent No. 4,069,217.

Using the process of U.S. Patent No. 2 49.1,832, the degree of de-sulfonation achieved depends on the amount of base introduced into the reaction; the intensity of the oxidation carried out (i.e., the relative amount of air or oxygen used, carefully avoiding severe oxidation conditions that could cause demethylation); the reaction time and temperature schedules followed and the dilution of the solids of the lignosulphonate-containing sulphite waste liquor to be treated, usually using water (with higher dilution conditions tending to lead to wider desulphonation likely due to increased availability of reactive molecules).

Although highly desirable partially desulfonated lignosulfonate materials are prepared by alkaline oxidation performed using sulfite waste broth containing n.

30-35% by weight of dissolved solids, the waste liquors boiled in the desulfonation process may contain only 14-10% or even 40% solids to obtain the preferred desulfonated products.

Virtually any alkali hydroxide solution can be used to perform a partial desulfonation reaction, although poorer alkalinity generally results in less desulfonation. More base or hydroxide (NaOH) is required when sugars and other saccharides are present (and are usually present in otherwise untreated sulfite waste liquors) in substantial amounts, to effect disintegration of saccharides. Generally, very good results are obtained when a sufficient hydroxide concentration is maintained throughout the desulfonation cooking to keep the reaction mass in a relatively high pH range of about 10.5-11. For example, a satisfactory ratio between the solids of the lignosulfonate and the hydroxide used in the reaction mass involves the use of an aqueous solution of lignosulfonate 69 8 60 having a concentration of about 31-32% by weight, a specific gravity of about 1.22-1.24 and containing in solution hydroxide concentration of about 140 g NaOH / l.

Sufficient oxidation conditions to achieve the desired desulfonation ranges of the ligosulfonate in the sulfite waste liquor can be achieved by feeding almost regardless of whether air or oxygen is passed through the boiling reaction mass, from about 20-25 grams to about 40-50 grams of elemental oxygen (i.e., 02) per 100 grams per desulfonation. lignin. In actual practice, about 27-35 g O 2 per gram of lignin is often used to obtain a more desirable range of partially desulfonated material.

Although variations may occur, temperatures in the range of about 140-170 ° C, and preferably about 165 ° C, are usually most preferably used. Naturally, the reaction mass is boiled until the desired degree of desulfonation (or when the vanillin by-product is important, its desired yield) is achieved. Usually, and at the 165 ° C level, the cooking time is of the order of about 45 minutes; the optimum time to be used, as will be appreciated by those skilled in the art, will depend on the reaction conditions and the degree of desulfonation desired for the partially desulfonated lignosulfonate material obtained. In most cases, it is most preferred (unless literally necessary for material handling purposes) to stop cooking while some free hydroxide is still present in the reaction mass. The aim is to prevent emulsification problems later during the recovery of the partially desulfonated lignosulfonate. Preferably and for said purpose, the reaction can accordingly be stopped when, for example, about 4-5 g / l of free NaOH are found to remain in the reaction mass.

The implementation of the process of U.S. Patent No. 2,491,832 thus produces an oxidized waste liquor containing partially desulfonated, generally acid-insoluble, chemically modified organic lignin substances. These are generally isolated or alternatively fractionated by acid precipitation, preferably with sulfuric acid, which removes the various sludge-producing, mostly calcium-based constituents therein.

:. 10 '69860

After precipitation, the purified partially desulfonated lignosulfonate material is generally dissolved in hydroxide to give the sodium salt.

The partially desulfonated lignosulfonate material thus obtained is clearly not obtainable from the original sulfite waste liquors, such as the so-called "lignosulfonates" ("water-soluble" calcium or equivalent lignosulfonate salt or lignosulfonic acid) described in, for example, U.S. Patent No. 8: In contrast, when partially desulfonated lignosulfonates are isolated by conventional means, such as acid precipitation or ultracentrifugation, they are exceptionally pure materials that contain substantially no sugars or polysaccharides and have only vanishing traces, if any, of combined sulfur. Furthermore, these lignosulfonates have relatively uniform and substantially unchanged relative molecular size properties as well as other characteristic and distinct properties.

Although sugar- and saccharide-containing sulfite waste liquor is also useful as a starting material for the preparation of partially desulfonated ligno-sulfonates from which the resulfonated mixtures used as retarders in the process of this invention are derived, otherwise treated sulfite waste liquors may equally be used. These may be, for example, those previously treated in various ways and for other original conversion purposes where sugars and / or saccharides are used and consumed, such as in the preparation of yeast or alcohol from crude sulphite waste liquor, or in other ways that give less sugar and / or saccharide-containing or saccharide-free sulfite waste broth.

Alkali-oxidized, partially desulfonated lignosulfonates, which are anionic polyelectrolytes with molecular sizes in the range of 69860 η and usually of the order of 1000-20,000 and from which the resulfonated products used as cement retarders in accordance with the present practice are obtained, generally have organic sulfonic sulfur, -SO3, a content which, calculated as a percentage by weight of sulfur, is broadly in the range from about 1/2 to 5% by weight. More preferably, for many purposes, this sulfur range is from about 1 3/4 to 3 1/4 by weight, although it is quite often preferred that the partially desulfonated lignosulfonate contains about 2.2 to 2.8 weight percent of combined sulfur in sulfone form.

The commercially available product "MARASPERSE CB" (TM), manufactured by AMERICAN CAN COMPANY, is an example of an alkaline oxidized, hydrolyzed, partially desulfonated lignosulfonate material useful as a starting material from which the solubilized resulfonated lignosulfonate-cemented hydronylated compounds of this invention can be derived.

"MARASPERSE CB" in its normally available form usually has the following typical analytical parameters and physical characteristics:

Typical analyzes (moisture free and percentage by weight): pH - 3% solution 8.5 - 9.2

Total sulfur as S,% 2.5 - 2.9

Sulfate sulfur as S,% 0.1-0.25

Sulfite sulfur as S,% 0 to 0.05

CaO,% 0.02-0.05

MgO »% traces - 0.03

Na 2 O,% 9.4 - 9.9

Reducing sugars,% 0 OCII3,% 12.4-12.9

Sodium lignosulfonate,% 99-99.6

Solids,% 92-94 UItraviolet analyzes (K-value represents baseline)

Upper UV: K solids at maximum (275 m ^, u) 29 - 30.5 K OCH3 at maximum - 225 -250 12

Differential UV: 69860

Max

Baseline K solid 9.5 to 10.5

Phenol -OH,% 1.8-2.1 OH / OCH 3 0.26-0.30

Physical properties

The usual form of powder

Moisture content (max,% H2O) 8.0 Color black

Bulk density (g / cm 2) 0.69 to 0.75

Solubility in water (%) 100

Solubility in oils and most organic solvents (%) 0

Surface tension, 1% solution (N / m) ca. 51.4 x 10- ^

Although known alkaline oxidized, hydrolyzed, partially desulfonated lignosulfonates, such as "MARASPERSE CB" products, have been considered desirable surfactants, dispersants, and detergent compositions useful as cement retardant additives under many conditions, as well as there are certain inherent limitations in critical borehole cementation applications and widespread use in this field. Notable of these difficulties, especially for partially desulfonated lignosulfonates, are their relatively limited solubility in aqueous saline solutions and their unsatisfactory reliability and predictability in terms of gel control and retardation of cement hardening time when used in borehole cement slurries and joints. .

The resulfonated lignosulfonates derived from the aforementioned partially desulfonated lysosulfonates are obtained, as mentioned elsewhere in this specification, by direct sulfonylation or sulfoalkylation of said alkali oxidized, hydrolyzed, partially desulfonated lignosulfonate starting material. Usually and most easily this is done with suitable sulfonating reagents in an aqueous solution of the starting material, preferably using stirring during the reaction (which is better the stronger it is and can be accomplished by mechanical stirring or stirring or in addition by the stirring effect of steam pressed into the reaction pulp). at any desired suitable temperature. In general, the reaction can be carried out at a temperature in the range of about 50 to 200 ° C, although it is usually desirable to run at a minimum boiling point (e.g., at least 100 ° C and up to 175 ° C) to avoid unnecessarily long reaction times. Usually a temperature of the order of 160 ° C is satisfactory for most re-sulfonation steps. The reaction is, of course, carried out at a corresponding pressure, i.e. between about 360-1400 kPa and preferably approx.

1000 kPa: at a pressure of 4 l when temperatures above the boiling point are used. The reaction time will generally vary with the temperature involved, with lower temperatures requiring longer times. At higher temperatures, resulfonation can be completed in only about 1/2 hour, while temperatures at the lower end of the scale may require up to 16 hours or more to complete the reaction. When the resulfonation soup is performed at about 160 ° C, it is completed in about one hour.

Any suitable sulfonation reagents can be used for the resulfonation reaction. When direct sulfonation is desired as opposed to sulfoalkylinol, it can be preferably carried out with an alkali metal (such as sodium) bisulfite or sulfur dioxide. The sulfoalkylation, which is often recommended, is performed with mixtures of the appropriate lower alkyl aldehyde and bisulfite. The sulfonate group itself, which is attached in the direct sulfonation, is, of course, -SO 3 H. Sulfoalkylates, which usually have alkyl units of 1 to 3 carbon atoms, have the structure - (O 2 O) -SO 3 H, where x is usually an integer from 1 to 3, and when x is greater than 1, the alkyl unit may be linear in attachment or, as is likely most often, thing, includes a short side chain. The common reference to sulfonation (i.e., attachment of SO 3 H groups) and sulfoalkylation is encompassed by the formula: (CyH wherein y has a value of 0-3 inclusive.

The aldehyde used in at least approximately stoichiometric proportions with the bisulfite in sulfoalkylations performed for resulfonation generally has the structure: RCH: 0, wherein R is a hydrogen atom or an alkyl group having 1 to 2 carbon atoms. It will be appreciated that mixed aldehyde reaction systems may be used if desired, although there is usually no particular advantage in this. Conventionally, it is highly desirable to perform a new sulfonation of the sulfomethylation reaction 11a using formaldehyde (CH 2 Cl 2 and sodium bisulfite (NaHSO 3)) as roagents to provide attachments to the resulfonated products.

As mentioned, approximately stoichiometric relative amounts of aldehyde and bisulfite reagents are used for resulfonation; and these are used in amounts calculated to provide the desired amount or amount of sulfonic acid units in the final sulfonated product finally obtained. In fact, a ± 20% variation in exact stoichiometric ratios is acceptable. The amount of formaldehyde used in the sulfomethylation reactions can range from about 1 1/2 to 12% by weight of the resulfonated desulfonated starting material, while bisulfite can be used in amounts of about 5-40% by weight, respectively. A particularly desirable resulfonylated product containing about 5 1/2% by weight of sulfur in the organic sulfonesulfonate form is obtained by administering as described MARASPERSE CB or a similar substance known under the trade name OPCOLOG A lignosulfonate, manufactured by Ontario Paper Company, Thoreau, Ontario , Canada, react with about 15% by weight of sodium bisulfite and 4 1/2% by weight of formaldehyde, based on the weight of "MARASPERSE CB", boiled for one hour at 160 ° C.

The resulfonated products used as starting materials in the practice of this invention may, if desired, contain any amount of intermediate from about 1 1/2 to 14 or 15% by weight of total sulfur in the United Organic Sulfonulfonate Form. Preferably, the amount of such sulfur is between about 2 3/4 and 10% by weight, and in most cases greater desirability is achieved with a weight percentage of sulfur of about 4 1/2 to 6 1/2% by weight.

Although not intended to be bound by any particular theory, it is believed that the alkali-oxidized, hydrolyzed, partially desulfonated lignosulfonate (obtained following the procedures of U.S. Pat. and usually on those side chain carbons that are in the alpha position relative to the ring and move away from the original substitutions made during the first 69860 sulfite cooking processes. On the other hand, it is believed that the sulfonate and sulphoalkyl units prepared in the practice of this invention are substantially, if not predominantly or completely located in the aromatic rings of the lignin molecules in ortho and para substitutions. Thus, the resulfonated product used as a good cement admixture in the practice of this invention is quite obviously a fundamentally different and different lignosulfonate from the lignosulfonate material found in spent sulfite lyes to give the starting lignosulfonates which are resulfonated in that practice.

A typical resulfonation reaction for preparing the starting materials used herein, which is incorporated herein by reference, is that described in U.S. Patent No. 4,065,313.

The retarder starting materials used in the process of the invention have, as mentioned, a relatively narrow and uniform molecular size as opposed to other lignosulfonates, so that in any special case these starting materials have a size range of about 10-20% (measured by diffusion to determine the relative molecular size described above). Typical re-sulfonated, desulfonated lignosulfonates suitable for the practice of this invention, as determined by this standard diffusion method, fall in the range of 2500-4500, typically 2900, 3500 and 4200; the relative molecular size maintained by these lignosulfonates throughout the period of time required for complete filter permeation by diffusion.

As previously mentioned, the wider range in relative molecular size of the lignosulfonate starting materials is about 1000-20,000; the region, as opposed to the region of conventional 1ignosulfonates measured by the above-mentioned diffusion method, shows a relative molecular size ranging from about 1,000 to 100,000 during the diffusion period.

The resulfonated, alkali oxidized, hydrolyzed, partially desulfonated acid condensation and / or lactone or cyanohydrin-reacted lignosulfonate-based borehole cement paste (or cementation paste) used in the process of this invention is generally used. 3% by weight based on the total weight of the mixture obtained. The more frequently used additive content is about 0.2-1.5% by weight, while often the most desirable range is between about 0.3-1% by weight.

16 69860

The amount of additive used in each case depends to a large extent on the cement curing schedule to be followed (according to API criteria) and on the temperature present during the actual curing of the cementitious mixture. Usually, relatively more retarder is required when higher cure temperature conditions occur.

The lignosulfonate additives used in the process of this invention are thus characterized by their ability to impart excellent resistance and resistance to premature curing and gelation to the cementitious compositions to which they are incorporated when exposed to very strong salt environments, such as are often found in many drilling rigs. the presence of natural saline waters (including seawater) as a result of seepage and seepage. They also tend to ensure a rare and unusually accurate predictability of the curing time and nature of the cement in mixtures at any given curing temperature, pressure and schedule, and in particular unexpectedly improved thermal stability.

The product additives have, as mentioned, a narrow or equal relative molecular size to the resulfonated starting materials described above.

Example 1

The commercially available product MARASPERSE CBO, sometimes referred to as OPCOLIC A, manufactured by American Can Company, forms an alkaline oxidized, hydrolyzed, partially desulfonated lignosulfonate material useful in the practice of this invention. MARASPERSE CBO product, as usual. is generally available, has the following typical analytical and physical characteristics: 69860

Typical analysis (calculated on a moisture-free basis) pH-3% solution 8.5 to 9.5

Total sulfur 1.0 to 1.5

Sulfate sulfur as S,% 0.1-0.25

Sulfite sulfur as S,% 0.05

Sulfone sulfur, as S,% 0.85-1.2

CaO,% 0.02-0.05

MgO,% traces - 0.03

Na% 6.3-7.5

Reducing sugars 0 OCH3 12.4-13.0

Sodium lignosulfonate 99-99.5

Physical characteristics

The usual form of powder

Moisture content (max)% 8.0 Color dark brown - black

Bulk density (g / cm 3) 0.69-0.75

Solubility in water% 100

Solubility in oil and most organic solvents 0

Surface tension, 1% solution (U / m) 51.4 x 10 ”3 (a) Resulfonated derivatives containing about 5.2% by weight of organic sulfone sulfur (based on the weight of the mixture) required to practice this invention are prepared as large scale preparations by sulfomethylation of the aforementioned oxidized, hydrolyzed, desulfonated lignosulfonates MARASPERSE CBO obtained by the method described in U.S. Patent No. 2,491,832, which is incorporated herein by reference.

The above-mentioned lignosulfonate starting material, MARASPERSE CBO lye, was sulfomethylated according to the following procedure, in which the following components are used at the indicated concentrations: 69860 18

Base: 100 Drill: approx. 22700 1 kg of finished product -1-Λ ^ -n0s -, --- kg Dry- Dry- kg of dry matter liters of liquid substance of substance kg / 1 kg

Marasperse CB 0-lye 71.29 21 300 24 270 0.30 6540

Sodium hydroxide 2.97 400 590 0.68 270

Formaldehyde, (Mol.

weight 38) 1,530 1,660 0.40 610

Sodium bisulfite (molecular weight 104) 22.28 - 2,040 - 2040

Total 103.22 24 330 28 560 0.39 9470

Final product 100 16 090 20 380 0.57 9170

NaOH was added to the lignosulfonate starting material up to a pK of 10.5 ± 0.2? 9% formaldehyde based on lye and total dry matter of NaOH; and slowly stirring 30% sodium bisulfite based on the lye and the total dry matter of NaOII. Stirring was continued for 30 minutes; and the reaction mixture is boiled for three hours at 170 ° C under a pressure of 690 kPa.

(b) To the sulfomethylated product thus obtained was slowly added with stirring 10% by weight of chloroacetic acid, based on the dry matter of the sulfomethylated product, at about 77 ° C. Stirring and heating were used for 20 minutes, after which 11% NaOH, based on the solids of the sulfomethylated starting material, was added. The reaction mixture was warmed to 90 ° C and allowed to react for an additional 5 hours at this temperature.

(c) Glucono-3-lactone to a concentration of 14% from the sulfomethylated starting materials was added to the reaction mixture and the reaction was continued for 30 minutes at 80-85 ° C.

(d) A product of the invention was prepared to which sufficient NaOH was added to achieve a pH of 9.0-9.5. The product was spray-dried to a dry matter content of 48-50% (and was very fluid when hot) to obtain a powder or made into a liquid by adding water to obtain a product with a dry matter content of 40 Z.

Example 2

An aqueous solution of the sodium salt of the sulfomethylated product (1111 g) prepared as described in Example 1 (a) and containing 500 g of dry matter was adjusted to an dry matter content of 69,860 in aqueous solution. The mechanically stirred system was heated to 80 ° C and treated with 20 g of sodium hydroxide (50?) And 50 g of chloroacetic acid. The reaction was allowed to complete in 5 hours at 80-90 ° C. The chloroacetic acid reaction product obtained had a pH of 8.2 and a solids content of 42.4%.

A portion (353.8 g) of an aqueous solution of the reaction product of resulfonated 1ignosulfonate and monochloroacetic acid, known as MARASPERSE CBO S-5CAA, prepared to a dry pressure content of 42.4% by weight (150 g) was further reacted at 7.5%. -no - i with glucono-delta-lactone (11.25 g) calculated on the dry matter in a mechanically mixed device. The temperature of the reaction medium was maintained at at least 60 ° C for at least 30 minutes.

A yield of 365.05 grams of the product obtained as an aqueous solution contained 44.17 wt.% Of solids in which solids (161.25 g) formed, as in Example 1, the sodium salt of the sulfomethylated reaction product of delta-gluconolactone and chloroacetic acid. The final product was diluted to a dry matter content of 40% by weight and named MARASPERSE CBO S-5CAA Lacquer for evaluation experiments.

Example 3

A second aliquot (353.8 g) of an aqueous solution of the reaction product known as MARASPERSE CBO S-5CAA lignosulfonate prepared as in Example 2 (before reaction with 3-lactone) to a dry matter content of 42.4% by weight (150 g) , was further reacted with 15 weights of KELIG 32 based on MARASPERSE CBO S-5CAA solids. KELIG 32, aqueous solution (39.8 g) was added at 56.4% by weight. (22.5 g) as a dry matter content of MARASPERSE CBO S-5CAA in a mechanically stirred device. The temperature of the reaction medium was maintained at at least 60 ° C for at least 30 minutes.

The yield obtained, yielding 393.6 grams as an aqueous solution, contained 43.83 wt.% Of solids in which the solids (172.5 g) formed the sodium salt of the chemical reaction product of KELIG 32 and MARASPERSE CBO S-5CAA. The final aqueous solution was diluted to a dry matter content of 40% by weight and named MARASPERSE CBO.

S-5CAA KELIG for evaluation tests.

Example 4

The samples of Examples 1, 2 and 3 above were tested for salt permeability, a measure of the utility of the products in the oil-borehole cement retarder when operating in strong saline solutions such as North Sea water. The test solution was an aqueous system mimicking "North Sea water" and contained 30 g / l sodium chloride, 1.16 g / l calcium chloride and 5.54 g / l magnesium chloride (which represented a total dissolved content of these salts of 36.70 g / l). .

Approximately 0.50 g of solids as a 40% by weight aqueous solution of the lignosulfonate-based products of Examples 2 and 3, as well as sulfomethylated MARASPERSE CBO, sulfomethylated MARASPERSE CBO S-5, and sulfomethylated intermediate reacted with chloroacetic acid, S-5CAA, was placed in 50 ml (ml) of North Sea water in 60 ml cans which were shaken mechanically for 1 hour. 10 ml aliquots of each sample were centrifuged in a De Laval centrifuge at 20,000 rpm for 2 minutes. The volume percentage of the slurry was recorded and is shown in the following table.

Sludge volume-S

Sample in "North Sea water" (37 g / l) MARASPERSE CBO 2.0 (Opcolig A) MARASPERSE CBO S-5 CAA 0.02 MARASPERSE CBO S-5 CAA lactone 0.02 (from Examples 1 and 2) MARASPERSE CBO S-5 CAA KELIG 0.019

In all cases, all products after resulfonation or sulfomethylation showed excellent salt tolerance to the parent compound and the starting material MARASPERSE CBO (Opcolig A).

It is clear that the terms and expressions used have been used as descriptive rather than restrictive terms. The use of these terms and expressions is not intended to exclude the equivalence of the features and parts thereof shown and described, and it is stated that various modifications are possible within the scope of the claimed invention.

Claims (6)

A method of sealing a zone around a borehole penetrating into a geological, underground formation, by injecting therein, for cementing purposes, a hydraulic cement mixture comprising about 0.05-3% by weight based on the weight of the obtained mixture. a retardant composition comprising a lignosulfonate or an alkali metal derivative thereof derived from sulfite effluent subjected to alkaline oxidation, hydrolysis and partial desulfonation with subsequent resultant, characterized in that the resulfonated lignosulfonate is subsequently reacted with: (a) an aryl acid; (b) a halocarboxylic acid and a hydroxy-substituted lactone; (c) the aforementioned hydroxysubstituted lactone; (d) a halocarboxylic acid and then with a derivative of a sugar acid containing sulfite liquor obtained by reacting the sulfite liquor with a cyanide, with subsequent hydrolyzing of the reaction product obtained; or (e) said derivative of the sugar acid containing sulfite liquor. Process according to claim 1, characterized in that the resulfonated lignosulfonate is reacted with a halocarboxylic acid. Process according to Claim 1, characterized in that the resulfonated lignosulfonate is reacted with a halocarboxylic acid and a hydroxy-substituted lactone.