DK144310B - PROCEDURE FOR PREVENTING CONCLUSION AND INHIBITING SWALLOWING OF FORMATION CUTS OR SHIFTLES - Google Patents

Description

in 144310

The present invention relates to a method for preventing clumping and inhibiting the swelling of formation chips or shales in an aqueous alkaline medium by treating it with polyvalent metal ions complexed with organic acids. Inhibition of swelling or inhibition of swelling (hereafter referred to as "inhibition") of hydrable clay slates has long been a problem faced by colloid chemists and professionals in the industrial use of these materials.

Eg. For example, the manufacture and use of ceramic products, pigments, drilling fluids, soil stabilizers and structural materials have often involved problems with clay shale swelling or slate swelling. The term "clay slate" is intended to refer to materials such as bentonite and similar clays and colloidal clay substances of the "gumbo" type and related substances which exhibit hydrodynamic volume increase when exposed to aqueous environments. Of particular importance is the geological formation of highly plastic tough clay ("gumbo") encountered by drilling underground boreholes.

These clay soils absorb water fairly easily and can swell to many times their original volume. By "swelling" or "swelling" is meant the hydrodynamic volume increase of the clay slate. By the terms "inhibition" and "inhibition of swelling" or "inhibition of swelling" is meant the ability of the process to reduce the hydration of clay slates, whereby they remain coherent and generally in their original size, shape and volume, and the process consists either of a pretreatment of the clay slate, where an aqueous system is added to the complex used here, and then the clay slate, or it consists of a finishing treatment, whereby the complex is added to the clay slate which is either partially or fully hydrated or the complex is added f. eg. during drilling, in the restoration or completion of underground drilling operations, where some of these materials referred to as formation shavings may have the capability referred to as hydrodynamic volume increase upon hydration. The aqueous alkaline medium may be fresh water, sea water, a saline solution or the like.

2

14431 O.

The clay sherds are formed by geological compression and compaction of very small particles and sediments over the centuries. The liquid in the particles and sediments is removed during compression of the sediment layers. As the pressure on the formation increases, the liquid will escape to more permeable formations.

Clay slates have varying dispersibility in water. The softer clay shifters will disperse more quickly, while the harder clay shifters will be more resistant to the dispersion phenomenon. Ionic forces are believed to play an important role in the ability of the shale to disperse. Eg. for example, a clay slate having a large amount of montmorillonite containing cations in interchangeable positions will be more easily dispersible. Consequently, these clay soils can exert a strong swelling pressure when subjected to the influence of alkaline media.

Swelling of clay slates is believed to be due to at least three phenomena: surface hydration, boundary layer swelling and osmotic swelling. Surface hydration is particularly active in clay soils due to the large surface area. Clay slates may have a grid type structure which allows the liquid to be absorbed between the layers as well as on the surface of the particle.

On the other hand, osmotic swelling occurs because there is a greater concentration of ions on the surface of the clay than in the liquid itself. This force draws the liquid into the clay particles. Of course, the degree of the osmotic effect of speech concentrations depends on both the shale particles and the liquid.

Previously, clay slurry has been somewhat reduced by replacing monovalent exchangeable cations with divalent cations, such as calcium. Many amine-type compositions have been used, but the results have not been entirely satisfactory. Not only are these compositions expensive, but they can oil wipe the surfaces.

When the clay slate in the suspensions is anionically charged, the charge is neutralized by adsorption of cations on the clay slate surfaces. As this will form an electrolytic bilayer, the particles will repel each other and thus disperse.

Because the adsorbed cations appear to be the major contributing force to this phenomenon, it is believed that swelling can be greatly reduced by the use of polyvalent metal ions. Polyvalent metal ions such as aluminum and the like are adsorbed more firmly than monovalent ions such as sodium.

One factor that plays a role in the use of polyvalent metal ions is their precipitation in alkaline environment.

In reality, some ionic substances can even precipitate out of a solution that reacts acidic. This is known from the use of a base and alumina which will produce a multidimensional polymer which will have an octahedral structure between the slate layers. However, in the preparation of such a soluble polymer, no more than approx. 2.4 OH groups per metal ion. Furthermore, this polymer is only stable in an acidic environment. Exposed to alkaline pH values, the aluminum ion will be separated from the solution. Therefore, the ion must be introduced in such a way that its normal propensity to precipitate is either completely removed or greatly reduced. Such a result can be obtained by reacting the ion to form a complex. Under certain circumstances, complexation of the ion can produce a chelate structure.

Aluminum lignosulfonate complexes prepared by treating alkaline calcium lignosulfonate with aluminum sulfate and then with a solution of an organic acid selected from acetic, formic, lactic oxal and tartaric acids have the property of partially replacing the lignosulfonate. in the aluminum complex, which has primarily been used as viscosity modifiers in aqueous drilling fluids.

For example, U.S. Patent No. 2,252,815 discloses that calcium = lignosulfonate can be treated with aluminum sulfate in an amount of 4144310 such that the sulfate is equivalent to the calcium content of the organic precipitate from the purified calcium lignosulphonate. Oxalic acid or other organic acid is later added in a preferred amount of 11% by weight based on the lignin present. It is believed that the material at least partially prevents the swelling and horizontal displacement by discarding clay layer found in pierced formations. However, it is possible that the presence of the lignosulfonate material may reduce the ability of the aluminum metal to function in a complex state solely as an inhibitor of clay slurry. In fact, the presence of lignosulfonate, depending on its concentration, may assist in the dispersion of the clay shale.

In other words, the aluminum and lignosulfonate serve to achieve completely different results. The inability of the known lignosulfonate mixture to be completely effective is probably due to a possible complex competition between lignosulfonate and the organic acid in the available aluminum ion.

When drilling, working with or completing underground boreholes to tap the occurrence of e.g. oil or gas, and especially when using a rotary drill with a drill bit attached to a drill rod, the drill bit will further penetrate the formation. The formation is composed of both organic and inorganic substances, such as minerals and clays. Most of these materials will hydrate when exposed to aqueous environments. Furthermore, some of these materials have the property of increasing the hydrodynamic volume during hydration, which is sometimes referred to as swelling. These materials are referred to here as formation chips.

As the drill bit teeth penetrate the formation, shavings are formed due to the impact of the drill bit. These drilling chips are wetted by the drilling fluid and give sticky and plastic 5

14431 O.

particles. The formation chips will be further kneaded until the liquid content of the drilling fluid becomes a mass varying from a rigid putty-like material to a sticky paste. Continued agglomeration of these drill bits on the surface of the drill bit insert results in "lump formation", i.e. to obtain a lot of tough and sticky material which adversely affects the cutting effect of the drill bit teeth, and which, together with other difficulties and adverse effects, greatly reduces the penetration rate. Lumping also occurs on drill collars and stabilizers with consequent adverse effects on the drilling operations. Lumping will also result in clogging of the surface current, disruption of the operation of flow meters and the like (all hereafter referred to as "drilling equipment" for convenience).

Although cleaning by drilling the nozzle of the drill bit and cleaning processes for surface drilling equipment means a relief, it would be desirable to remove the cause of clumping rather than treating the result of the clumping.

It has now surprisingly been found that swelling of clay slides in aqueous alkaline medium can be significantly inhibited by the use of special polyvalent metal ion complexes which probably adhere to the inner and / or outer surfaces of the clay slice and which are not light to remove by electrolytic forces, and that the presence of such polyvalent metal ion complexes on the surface of the drilling equipment during the drilling operations will provide a means of removing the lumping tendency both of formation drilling chips and of additives used in the drilling fluid. The result is that these solids will not collect on the surface of the equipment.

Although not fully understood, it is believed that the polyvalent metal ion complexes reduce or inhibit the hydration of most of the formation drill chips, leaving most of the particles cohesive or "cemented" and substantially their original size and form. The metal ion complexes prevent the kneading of both hydrating and non-hydrating formation drill bits, thereby avoiding the formation of cool and sticky putty-like substances.

One factor of importance when using polyvalent metal ions is their precipitation in alkaline environment. Therefore, the ion must react in such a way that its normal propensity to precipitate out of the solution is either completely removed or greatly reduced. Such a result can be obtained by reacting the ion to form a complex and the process according to the invention is characterized by the characterizing part of claim 11.

The complex can be prepared in an aqueous solution by subjecting the selected polyvalent metal ion to a sufficient amount of the complexing component to prevent precipitation of the metal ion in alkaline medium. The metal ion is preferably used in the form of a water-soluble salt such as chromium sulfate, aluminum sulfate and aluminum chloride. The metal ion can be used in the form of an anhydrous compound or in hydrated form.

When an anhydrous metal compound is used, the reaction can preferably be carried out in an aqueous system. The reaction may sometimes be necessary at elevated temperature. However, the reaction will usually end at room temperature. After dissolving the metal ion and using it after application of heat, the complexing component is added and heated or allowed to stabilize briefly (generally 15-45 minutes) to form the complex . The solvent is then removed in a manner known per se, such as by vacuum evaporation. The resulting material can then be ground to obtain a product with a large surface area.

144310 7

In the preparation of the complex used in the process of the invention, it is not necessary that it be prepared in a solution. When using a solution without solution, the metal ion material can be simply mixed with the complexing component. This preparation will not normally require heating.

As indicated above, the effect of the complexing component is to make the metal ion complex bound so that it will not precipitate out of solution in alkaline medium.

In general, a 1: 1 equivalent weight ratio of metal ion to the complexing component is preferred. It has not been found to be critical with an excess of the complexing component relative to the metal ion, and proportions beyond the 1: 1 ratio can be used with excellent results. Reactant ratios below 1: 1 by weight equivalent basis can also be used. For example, when aluminum sulphate is used to supply the metal ion, it has been found that the metal ion can be made complex with e.g. citric acid, oxalic acid and tartaric acid, using an equivalent weight ratio of polyvalent metal to the complexing acid of at least 1: 0.2-1.0, using the complex at a concentration of at least 2.85 3 kg / m of the alkaline medium. The choice of the particular metal ion and its form will greatly alter the required amount of the complexing component required to form the resulting complex. Also, the complexing component chosen will be a factor of importance. In addition, the special alkaline environment in which the complex is used must be taken into account. However, since the purpose of using a complex structure is to ensure a sufficient amount of metal ions to prevent aggregation and / or inhibit swelling, titration and related test methods can be used to determine the amount of metal ions adsorbed by the formation particles, drilling fluid additives. or a selected clay slate. For the selected application, samples of solids, such as formation drilling chips and clay shale, in the selected environment can be separated to obtain at least two samples. The first test shall not be subjected to a complex compound and shall serve as a blank or comparison test. The second sample should be subjected to the influence of several concentrations of complex compounds prepared at different equivalent weight ratios of selected metal ion to complexing component. By visually observing aggregation and clay inhibition samples, such as e.g. used in the Examples below, a determination of the particular complex and its concentration of inhibition may be made which may be used for a particular case.

In practical drilling, it has been found that the starting concentrations. 3 tions of the complex in the range of between 2.85 kg / m and approx.

3 28 kg / m will be sufficient to prevent clumping in most cases. Then a titration test can be performed to determine the amount of metal ion material needed to supplement the adsorbed ion amount in the aqueous alkaline solution. See, e.g. Furman, Scott's Standard Method of Chemical Analysis, Vol. 1, 6th Edition, p. 50 (Van Nostrand Company, Inc., March 1962).

In the process of the invention, the complex formed as above is utilized either for a pretreatment, i.e. before the clay slate has been substantially exposed to an aqueous medium for inhibiting swelling, or as a finishing treatment, ie. for inhibiting swelling of the clay slate after it has been exposed to the aqueous medium or during the drilling of underground boreholes, the surfaces of the drilling equipment being exposed to an aqueous circulation system either inside or outside the borehole.

Inhibition of swelling of clay shale particles can be determined by various tests. Specifically, test methods have been used to determine the rheological properties of suspension systems. In the samples described below, rheology has been determined at room temperature using 9

14431 Q

the "Model 35 Fann Viscometer", a common instrument for measuring the rheological properties of suspensions, and which is widely accepted and in many industrial enterprises where rheological data is important. "Fann viscosimeters" are of the concentric cylinder type in which the sample liquid is contained in an annular space between the cylinders. The rotation of the outer cylinder at known speeds is accomplished by precision drives which produce a torque transmitted to the inner cylinder by means of This torque is balanced by a coil spring and the angular impact is read on a disc or by means of appropriate sensors on a measuring device or a registrar. Fins which can be converted to viscosity or viscosity-landed viscosity by appropriate calculations.

When clay slate absorbs water, the particles will swell and fill a larger hydrodynamic volume than that filled by the same clay slate which has not been hydrated or alternatively has been hydrated but swelled less. Thus, for a given shear rate, a hydrated, swollen particle will have a higher shear stress than a hydrated but not swollen particle. Particle swelling must not be confused with particle dispersion. A dispersed system may contain either swollen clay particles and / or non- or partially swollen clay particles. A deflocculant may produce a non-coagulated system but may not necessarily inhibit swelling of the particles. Therefore, the appearance of a relatively low Fann number at high shear rates for a given concentration of solids is a sign of swelling inhibition.

In treating the clay surface to inhibit swelling, a method should be employed which comprises the following steps: 1) preparation of an aqueous system, 2) addition to this system of a polyvalent metal ion, as claimed in claim 1, wherein said ion is made complex by a component selected from acetic acid, citric acid, formic acid, lactic acid, oxalic acid and tartaric acid as well as the alkali metal and ammonium salts and mixtures thereof, 3) adjusting the pH of the system to at least 7.0, and 4) adding to it system of a predetermined amount of clay slate to thereby produce a suspension.

The pH can also be adjusted to the alkaline side in step 1) before the addition of the complex.

In order to inhibit a fully or partially hydrated clay slate, a process consisting of the following steps must be used: 1) exposure of the clay slate to the influence of an aqueous medium containing a polyvalent metal ion, whereby said ion is complexed with a component selected from acetic acid , citric, formic, lactic, oxalic and tartaric acids, the alkali metal and ammonium salts and mixtures thereof, and 2) adjusting the pH of the suspension to at least 7.0.

The pH of the medium can again be adjusted to the alkaline side before the addition of the complex.

In drilling operations and to inhibit swelling and to avoid clumping, a process consisting of the following steps may be employed: A) preparation of an aqueous system, B) addition to this system of a polyvalent metal ion as claimed in claim 1, the polyhydric metal ion in the aqueous system having a complexing component which is acetic acid, citric acid, formic acid, lactic acid, oxalic acid and tartaric acid, the alkali metal or ammonium salts or mixtures thereof, D) adjusting the pH of the system to at least 7, 0, E) circulating the system through and out of an underground borehole; F) bringing formation drilling chips into the complex-bound metal ion in the circulation system.

Step "D" can also be performed in the context of step "A".

The aqueous system may be either fresh water, a saline solution, sea water or possibly combinations thereof. The aqueous system may also contain other known drilling fluid additives such as bentonite, barite, ethoxylated organic polymers, asbestos, rubber, polymers and similar viscosity modifiers and chemical diluents.

The polyvalent metal ion can be added to the aqueous system in the manner described herein or added in combination with other drilling materials. Preferably, the material is added either alone or in combination during normal mixing operations in the mud holes. Complex formation of the metal ion will normally occur immediately after the addition of the complexing component. The following examples will further illustrate the present invention.

Example I

This example shows a preparation of the polyvalent metal ion complex. Aluminum sulphate was mixed with varying equivalent weight amounts of tartaric acid, citric acid and potassium bitartrate without the use of solvent or heating. The following complexes were prepared.

12 144310

Table 1 Equivalent

Alumi- Yin-Ci- Kali weight for- Al-ind-% Al i

Comium Acid Throne Bitumen Team Hold Complex Plex Sulfate Acid Funnel Al2 (SO4) 3 / Form Weight g Weight g Weight g Weight g Complex Weight% Forming __________ Component___ A 39.98 10.81 1.0 / 0.4 6.38 40.0 B 39.98 13.51 1.0 / 0.5 6.05 50.0 C 39.98 16.21 1.0 / 0.6 5.76 60.0 D 39.98 9.22 1.0 / 0.4 6.58 40.0 E 39.98 11.53 1.0 / 0.5 6.29 50.0 F 39.98 13.83 1.0 / 0.6 6.02 60.0 G 39.98 13.55 1.0 / 0.4 6.05 40.0 H 39.98 16.94 1.0 / 0.5 5.69 50.0 I 39.98 20.33 1.0 / 0.6 5.37 60.0

Example II

This example demonstrates the efficacy of a polyvalent metal ion complex to inhibit the swelling of clay slate in comparison with an aluminum lignosulfonate, which is a material which serves as a dispersant and which may interfere with the inhibition properties of the metal ion.

An aluminum lignosulfonate was prepared by dissolving 300 g of calcium lignosulfonate containing 5.0 wt. Of calcium in 658 cm 2 of water to give a solids content of approx. 40% by weight at a pH of 4.6. This material was heated to 80 ° C and stirred for 30 minutes. Calcium sulfate of the reaction medium was precipitated by the addition of 85.24 g of aluminum sulfate. The calcium sulfate was removed by filtration. The aluminum lignosulfonate filtrate was again warmed to 80 ° C and 50.17 g of tartaric acid were added. After heating and stirring for 30 minutes, the pH was found to be 1.6. 38.7 g of 50 wt% sodium hydroxide were added to raise the pH to 2.6. The reaction product was spray dried.

For comparison purposes, an aluminum tartrate complex was also prepared which did not contain lignosulfonate. The complex contained 1 mole of aluminum to 1 mole of acid. 53.31 g of aluminum sulphate were dissolved in 100 cm 2 of water and heated to 80 ° C. 12.01 g of tartaric acid was added and the solution was stirred at 80 ° C for 30 minutes. The reaction product is dried at 80 ° C under a vacuum of 584 mm Hg and ground.

The reaction product was tested for inhibition of clay slurry using a 9% aqueous suspension of sodium bentonite. To the 350 ml of deionized water, the selected sample was added. 35 g of sodium bentonite were then added to each sample containing 5 g of chromium lignosulfonate, 3 wt% potassium chloride and 5 g of the aluminum lignosulfonate tartaric acid material, respectively. The samples were mixed with the original clay slate by means of an electric mixer and the pH was adjusted with sodium hydroxide. The samples were heated in glass bowls in a rotary oven at 66 ° C for 16 hours (hereinafter commonly referred to as "hot rolling"), cooled to room temperature and re-mixed on an electric mixing machine. The rheological properties were determined both before and after the hot rolling. The results of this experiment were as follows:

Table 2

Degrees Found at the following order. per. min (outer cylinder) 600 300 200 100 6 3 pH

Base, initially 221 156 128 89 20 14 10.0

Base, hot-rolled> 300 243 206 154 48 36 9.3

Complex, initially 6.5 3 2 1 0 0 9.6

Complex, hot-rolled 9 5 5 2 00 8.7

Al-LSO ^, initially 21 11 7.5 3.5 0 0 9.4 A1-LS0 ^, hot roll 26.5 14 10 5 0.5 0.5 8.0

Cr-LS0 ^, initially 10.5 7 3.5 0 0 9.4

Cr-LS0 4, hot roll 29.5 15 10 5.5 0.5 0.5 8.3 KCl, initially 22 18 16 14 12 13 9.4 KCl, hot roll 45 37 33 30 25 26 7.9

Example III

The following example demonstrates the utility of an aluminum sulfate = tartaric acid complex for inhibiting swelling of sodium bentonite. Variable amounts of the complexes were dissolved in 350 ml of deionized water, then the pH was adjusted to 9.5 with sodium hydroxide. 35 g of sodium bentonite was then added to the sample. The rheological conditions were determined as in the previous examples, both before and after the hot rolling. The results of this experiment showed that the complex was effective in varying amounts to inhibit the swelling of sodium bentonite. All readings were extremely low and indicated a low shear stress at all shear conditions. The results of this experiment were as follows:

Table 3A

Untreated sodium bentonite

Degrees Found by the following andrein. per. mine. (outer cylinder)

600 300 200 100 6 3 pH

Initially 184 128 103 71 15 11 9.4

Initially 195 137 111 77 17 12 9.5

The hot roll 296 225 190 142 44 35 8.8

Hot roll 300 234 198 148 47 35 9.3

Table 3B

Aluminum sulphate / tartaric acid (1 / 0.4 equivalent weight ratio)

Degrees Found at the following turn. per. mine. (outer cylinder)

600 300 200 100 6 3 pH

5 g, initially 8 4 3 1 0 0 9.6 5 g, hot roll 12 6 4 2 0 0 9.1 2.5 g, initially 12 6 4 2 0 0 9.6 2.5 g, hot roll 18 10 7 4 0.5 0.5 10.0 1.75 g, initially 17 9 7 4 0.5 0.5 9.9 1.75 g, hot roll 25 14 10 6 0 0 10.2 0.88 g, initially 40 27.5 22.5 16 , 5 6 5 10.0 0.88 g, hot roll 62 36 26 15 1 1 9.8 15 144310

Table 5C

Aluminum sulphate / tartaric acid (1 / 0.6 equivalent weight ratio)

Degrees Found by the following andrejn. per. mine. (provides cylinder) 600 300 200 100 6 3 pH

5 g, initially 8 4 2.5 1 0 0 9.7 5 g, hot roll 14 7 5 3 0 0 9.5 2.5 g, initially 11.5 6 4 2 0 0 9.7 2.5 g, hot roll 19 11 8 5 1 1 10.0 1.75 g, initially 16 8 6 3 0.5 0.5 9.7 1.75 g, hot roll 25 13 9 5 0.5 0.5 9.8 0.88 g, initially 40 27 22 16 5 4 9.9 0.88 g, hot roll 42 39 28.5 16.5 2 1.5 9.6

Table 3D

Aluminum sulphate / potassium bitartrate (1 / 0.4 equivalent weight ratio)

Degrees Found at the following cm turn. per. mine. (provides cylinder)

600 300 200 100 6 3 pH

5 g, initially 8.5 4.5 3 2 0.5 8.8 5 g, hot roll 9.5 4.5 3.5 2 0 - 7.9

Example IV

This example demonstrates the utility of the complex to inhibit the swelling of a hydrated clay changer. Various amounts of the complex were added to a 7% sodium bentonite suspension. After adding the selected sample, the pH of the suspension was adjusted to 9.5 with sodium hydroxide. The particular rheological conditions were determined as in the above example. The results of these experiments showed that the complexes were equally effective in post-treatment inhibition processes. The results of this experiment were as follows:

Table 4A No additive

Degrees Found by the following andrejn. per. mine. (provides cylinder)

600 300 200 100 6 5 pH

Blank sample, initially 111 71 54 34 6 4.3 10.1

Blank sample, initially 109 70 54 34 6 4 9.3

Blank specimen, hot-rolled 149 100 79 52 9 6 9.4

Blank sample, hot-rolled 141 96 76 50 9 6 8.9

Table 4B

Aluminum sulphate / tartaric acid (1 / 0.4 seq valent weight ratio)

Degrees Found by the following andrejn. per. mine. (provides cylinder)

600 300 200 100 6 3 pH

5 g, initially 47 24.5 17 9 1 1 9.3 5 g, initially 44 24 16.5 9 1 1 8.8 5 g, hot roll 41 22 15 8 1 1 8.3 5 g, hot roll 43 23, 5 16 9 1 '0.5 8.0 17 1Λ Λ 3 1 Ο

Table 4C

Aluminum sulphate / tartaric acid (1 / 0.5 sequential weight ratio)

Degrees Found by the following andrejn. per. mine. (outer cylinder) 600 500 200 100 6 3 pH

5 g, initially 45 24 16.5 9 1 1 9.2 5 g, hot roll 44 23 16 8 0.5 0 8> 4 2.5 g, initially 59 33 23 13 1.5 1 9.1 2.5 g, hot roll 75 44 32 19 3 3 8.5 1.75 g, initially 70 40 29 16 1.5 1 9.3 1 75 g, hot roll 94 56 42 25 4 3 9.0

Table 4D Tartaric acid (Non-complexing)

Degrees Found at the following cmdrejn.pr. mine . (outer cylinder) 600 300 200 100 6 3 _ES_ 5 g, initially 63 40 31 22 10 10 8> 7 5 g, hot roll 159 109 88 60 25 25 8> 5

Table 4E

Aluminum sulphate (not complexing)

Degrees Found at the following other jn.pr.min. (outer cylinder) 600 300 200 100 6 3 _ -ES- 5 g, initially For viscost for a measurement.

5 g, hot roll 231 229 218 206 180 159 10 »3 144310 18

Example V

Experiments were performed and the results were determined to determine the effect of various concentrations of aluminum sulfate / tartaric acid complexes to inhibit swelling of Vermilion Parish, Louisiana, "gumbo" slate. 5 g with varying ratios of an aluminum sulfate / tartaric acid complex were dissolved in 150 ml of deionized water. The pH was then adjusted to 9.5 with sodium hydroxide. 200 g of "gumbo" * was then added to each sample. The results showed that in all conditions investigated, the complex was able to effectively inhibit swelling of the clay slate. The results of this experiment were as follows:

Table 5A No additive

Grades Fann · at the following turn. per. mine.' (outer cylinder) 600 500 200 100 6 5 pH

Blank sample, initially 56 28 15 12 8 8 9.4

Blank sample, hot-rolled 78 68 63 59 52 52 8.3

Table 5B

Aluminum sulphate / tartaric acid (1 / 0.4 equivalent weight ratio)

Grades Famrved following turn. per. mine. (outer cylinder)

600 300 200 100 6 5 pH

5 g, initial 15 8 6 3.5 0 0 9.2 5 g, hot roll 40 32 28 24 17 16 8.1 19 144310

Table 5C

Aluminum sulphate / tartaric acid (1 / 0.5 equivalent weight ratio)

Degrees Found at the following turn. per. mine. (provides cylinder)

600 300 200 100 6 5 pH

5 g, initially 15.5 9 7 5 1 1 9.2 5 g, hot roll 45 53 29 25 17 16 8.2

Table 5D

Aluminum sulphate / tartaric acid (1 / 0.6 equivalent weight ratio)

Grader Farm by the following evils. per. mine. (provides cylinder)

600 500 200 200 6 5__pH

5 g, initially 16 9 7 5 1 1 9.2 5 g, hot roll 41 30 27 23 15 15 8.3

Example VI

This example demonstrates the effectiveness of various equivalent weight ratios of an aluminum sulfate / citric acid co-complex to inhibit swelling in aqueous, alkaline environments containing sodium bentonite. The selected complexes were dissolved in 350 ml of deionized water. The pH value in-. was then adjusted to 9.5 with sodium hydroxide. 35 g of sodium bentonite were then added. The rheological conditions were measured as in the previous examples. The results of the experiment showed that the complex was quite effective in inhibiting swelling of the clay samples. The results of these experiments were as follows: 20 144310

Table 6A No additive

Degrees Farin by the following andrejn. per. mine. (provides cylinder)

600 500 200 100 6 5 pH

Blank sample, initially 199 144 123 89 36 31 9.4

Blank sample, hot-rolled 300 248 213 164 66 56 8.8

Table 6B

Aluminum sulphate / citric acid (1 / 0.25 equivalent weight ratio)

Degrees Found by the following andrejn. per. mine. (provides cylinder)

600 300 200 100 6 5 pH

5 g, initially 10 5 3 1.5 0 0 9.1 5 g, hot roll 11 6 4 2 0 0 8.2

Table 6C

Aluminum sulphate / citric acid (1 / 0.8 equivalent weight ratio)

Degrees Found by the following andrejn. per. mine. (provides cylinder)

600 300 200 100 6 3 pH

5 g, initially 9.5 5 3.5 2 0.5 0.5 9.4 5 g, hot roll 18 10 7 4 0 0 9.0 2.5 g, initially 15 8 6 3 0.5 0.5 9, 5 2.5 g, hot roll 28 16 12 7 1 0.5 9.2 1.75 g, initially 19 10 7 4 0.5 0.5 9.6 1.75 g, hot roll 41 24 18 10 1.5 1 9.3 0, 88 g, initial 35 21 16.5 11 1 1 9.7 0.88 g, hot roll 75 47 36 22.5 3 3 9.2 21 144310

Table 6D

Aluminum sulphate / citric acid (l / l equivalent weight ratio)

Degrees Found by the following andrejn. per. mine. (provides cylinder)

600 500 200 100 6 3 pH

5 g, initially 10 5 3.5 2 0.5 0.5 9.4 5 g, hot roll 17.5 10 7 4 0 0 9.0 2.5 g, initially 7.5 7 2.5 2.5 0 0 9, 6 2.5 g, hot roll 24 13 9 5 0 0 9.4 1.75 g, initially 19 10.5 7.5 4 0.5 0.5 9.8 1.75 g, hot roll 38 22 16 9 1 0 9.4 0, 88 g, initially 45 29 22 15 3 3 9.8 0.88 g, hot roll 78 49 38 24 5 4 9.1

Example VII

Experiments were performed and the results were determined to determine the effectiveness of a complex compound prepared using salts of a suitable acid as the complexing component.

Clay slate inhibition experiments were performed in Example VI above. The results showed that effective complexes could be obtained by introducing salts of an appropriate acid to form the complex. The results of this experiment were as follows:

Table 7A

Aluminum sulphate / sodium citrate (1 / 0.4 equivalent weight ratio)

Degrees Found at the following cm turn. per. min (providing cylinder)

600 500 200 100 6 3 pH

5 g, initially 11.5 642 0.5 0.5 9.0 5 g, hot roll 17.5 10 .7 4 0.5 0 8.3 2.5 g, initially 16.5 9 6 3 0.5 0, 9.1 22 144310 (Table 7A continued)

600 500 200 100 6 5 pH

2.5 g, hot roll 31 18 14 8 1 0.5 8.6 1.75 g, initial 19.5 10 7 4 0 0 9.4 1.75 g, hot roll 42.5 25 19 11.5 3 1 9.0 0.88 g, initially 38 23 18 12 2 1.5 9.6 0.88 g, hot roll 66 42 32 20 4 3 9.0

Table 7B

Aluminum sulphate / potassium citrate (1 / 0.4 equivalent weight ratio)

Degrees Found at the following cm turn. per. min (providing cylinder)

600 300 200 100 6 3 pH

5 g, initially 8 4 3.5 1 0 0 9.2 5 g, hot roll 19 11 8 4.5 1 1 8.6 2.5 g, initially 13.5 7 5 3.5 0.5 0.5 8, 9 2.5 g, hot roll 29 17 13 7.5 1.5 1 8.5 1.75 g, initial 17 9 6.5 3.5 0.5 0.5 9.2 1.75 g, hot roll 39 23 17 10 1 1 8 , 8 0.88 g, initially 29 17 13 8.5 1 1 9.6 .0.88 g, hot roll 66 41 # 31 20 4 3 9.2

Example VIII

Experiments were performed to determine the ability of different amounts and different equivalent weight ratios of aluminum complexed to citric acid to inhibit the swelling of hydrated 7% sodium bentonite suspensions. An appropriate amount of the complex sample was added to the suspensions and the pH values adjusted to 9.5 with sodium hydroxide. The rheological conditions were determined sera in the previous examples. The results showed that these complexes were effective in inhibiting the swelling of the sodium bentonite suspensions. The following results were obtained: 0, 144310 25

Table 8A No additive

Grader Farm at the following order. per. mine. (outer cylinder) 600 500 200 100 6 3 PH

Blank sample, initially 95 64 50 35 10 9 8.9

Blank sample, initially 103 67 52 34 7 6 9.1

Blank sample, hot-rolled 117 81 65 45 12 10 8.9

Blank sample, hot-rolled 180 127 103 72 15 11 9.0

Table 8B

Aluminum sulphate / citric acid (1 / 0.4 equivalent weight ratio)

Degrees Found by the following andrejn. per. mine. (outer cylinder) 600 300 200 100 6 3 pH

2.5 g, initial 59 33 23.5 13 1.5 1 9.2 2.5 g, hot roll 83 50.5 37.5 22.5 4 3 8.8 1.75 g, initial 66 38 28 16 2 1 9.3 1.75 g, hot roll 89 53 40 24 3 2 8.9 24 144310

Table 8C

Aluminum sulphate / citric acid (l / l equivalent weight ratio)

Degrees Found by the following andrejn. per. mine. (outer cylinder) 600 300 200 100 6 3 pH

2.5 g, initially 45 26 19 11 1 1 9.2 2.5 g, hot roll 6l 37 28 17 3 2 8.7 1.75 g, initially 56 35 27 17 2 2 9.4 1.75 g, hot roll 74 45 34 21.5 4 4 8.8 0.88 g, initially 63 41 32 22 5 4 9.1 0.88 g, initially 61 39 30 21 4 3 9.5 0.88 g, hot roll 97 66 50 32 5 4 8.8 0 , 88 g, hot roll 85 55 42 28 6 5 8.9

Example IX

To determine the efficiency of the complexes to inhibit swelling of clay shale in environments other than deionized water, experiments were performed using 7% hydrated suspensions of sodium bentonite contaminated with 1350 ppm calcium ion and magnesium ion with 1.5% sodium chloride. The rheological conditions were determined as in the previous examples. The results of this experiment showed that the complexes were equally effective in aqueous environments other than deionized water. The results were as follows:

Table 9A No additive

Degrees Found at the following cm turn. per. mine. (outer cylinder) 600 300 200 100 6 3 pH

Blank sample, initially 86 75 68 62 46 45 0.1

Blank sample, initially 79 67 63 58 45 43 - 25 144310 (Table 9A continued)

600 300 200 100 6 5 pH

Blank sample, hot-rolled 61 51 46 40 27 26 7.1

Blank sample, hot-rolled 58 48 43 39 27 26

Table 9B

Aluminum sulphate / citric acid (1/1 equivalent weight ratio 1 d)

Degrees Found at the following turn. per. mine. (outer cylinder) 600 300 200 100 6 3 pH

Degrees Found 5 g, initially 20 12 9 5 1 1 9.1 5 g, initially 20 11 8.5 5 2 2 5 g, hot roll 43 29 23 18 11 10 3.8 5 g, hot roll 30 19 15 11 7 7 8.6

Example X

Experiments were performed and the results were evaluated to determine the effectiveness of metal complexes containing metal ions other than aluminum to inhibit the swelling of sodium bentonite. The experiments were performed as in the previous examples. 5 g of the selected material was dissolved in 350 ml of deionized water to form the complex and the pH was adjusted to 9.5 with sodium hydroxide. 35 g of sodium tri-bentonite was then added to give a suspension. The rheological conditions were determined as in the previous examples. The results of this experiment were as follows: 26 U4 310

Table 10A

Ferric chloride / citric acid (l / l equivalent weight ratio)

Degrees Found at the following turn. per. mine. (outer cylinder). 600 500 200 100 6 5 pH

5 g, initially 27 17.5 14 9 3 3 8.8 5 g, initially 36.5 25 20 14.5 7 6 8.8 5 g, hot roll 51 32 25 11 4 3 8.0 5 g, hot roll 63 41 32 21 6 5 8.1

Table 10B

Ferric sulfate / citric acid (l / l equivalent weight ratio)

Grader Farm at the following turn. per. mine. (outer cylinder). 600 300 200 100 6 3 pH

5 g, initially 25 16 12.5 8 3 2.5 8.7 5 g, hot roll 46 29 22.5 15 3 3 7.9

Table 10C

Ferric chloride / tartaric acid (l / l equivalent weight ratio)

Degrees Found at the following cm turn. per. mine. (outer cylinder). 600 300 200 100 6 3 pH

5 g, initial 8 8 6 3 0 0 8.3 5 g, hot roll 30 17.5 13 7.5 2 2 7.4 27 144310

Table 10D

Chromium sulphate / citric acid (1/1 equivalent weight ratio)

Degrees Found at the following turn. per. mine. (outer cylinder). 600 500 200 100 6 5 pH

5 g, initially 62 44 36 28 15 14 8.3 5 g, hot roll 95 64 50 36 13 12 8.5

Table 10E

Zir.convlsulf at / citric acid (l / l equivalent weight ratio)

Degrees Found by the following evils. per. mine. (outer cylinder). 600 300 200 100 6 3 pH

5 g, initially 20 11 8 4.5 0.5 0 8.6 5 g, hot roll 56 35 26 16.5 3 2 8.5

Table 10F

Lantern nitrate / citric acid (1/1 equivalent weight ratio)

Degrees Found by the following evils. per. mine. (outer cylinder). 600 300 200 100 6 3 pH

5 g, initially 20 11 8 4.5 0 0 9.0 5 g, hot roll 30 17 12 6.5 0 0 8.4 28 1443 10

Table 10G

Ferrosulfate / citric acid (l / l equivalent weight ratio)

Degrees Found at the following cm turn. per. mine. (outer cylinder). 600 500 200 100 6 5 pH

5 g, initially 19 11 8 5 1 0 7.6 5 g, hot roll 23 12.5 9 5 0.5 0 8.3

Table 10H No additive

Degrees Found by the following andrejn. per. mine. (outer cylinder). 600 300 200 100 6 3 pH

Blank sample, initially 150 112 95 74 41 40 9.3

Blank sample, hot-rolled 238 171 144 110 52 48 8.4

It should be noted that the investigated complexes in Table 10B were made soluble by the addition of sulfuric acid. In addition, the samples examined in Tables 10A and 10B showed that although swelling inhibition occurred, the metal ion was not fully complexed as a small amount of precipitate appeared at a pH below 7 · As shown in these tables, some applications may and circumstances necessitate increased levels of a complexing component to completely bind the metal ion complex, although some satisfactory complexation and inhibition of swelling will occur at less than the stoichiometric levels. This is further shown by the complexes in Table 10D, where it was found that although no separation at alkaline pH values below about 5% was observed. 9.5, there was little separation when the pH rose above 9.5. The experiments showed that this problem can be corrected by using increased levels of the complexing component to form the complex.

2g 144310

Example XI

Experiments were performed and the results were evaluated to determine the effect of calcium ion contaminants in an aqueous alkaline system containing the complex used according to the invention. If the metal ion is not completely complexed, calcium will react with the complexing component, allowing the metal ion to be separated by the solution. Although some equivalent weight ratios of the metal ion to the complexing component under investigation produced a cpalescence, the complexes were found to be clearly stable at concentrations of calcium as high as 3000 mg / liter and an alkaline pH as high as 11.45 ·

Aqueous solutions containing 2 g of an aluminum sulfate / citric acid complex were prepared. Sufficient sodium chloride was added to give a 6% concentration. Calcium chloride dihydrate was used to prepare solutions containing 20.00, 3000 and 12000 ppm calcium ion. The solutions were mixed to give a final volume of 100 ml containing 1 g of aluminum complex, 3% sodium chloride and the selected concentration of calcium ion. Two mixtures were prepared, one with an aluminum sulfate / citric acid complex at a 1 / 0.6 equivalent weight ratio and one at a 1/1 equivalent weight ratio. These solutions were titrated with a sodium hydroxide solution containing 0.25 g / ml. ml. Volume measurements were found to have an accuracy of 0.001 ml when using a microburette. Each solution was stirred with a magnetic stirrer while increasing amounts of sodium hydroxide solution was added. After each increase of the sodium hydroxide addition, the pH was recorded after stabilization, and then solubility observations were made. All data were obtained at room temperature. The results of this experiment are shown in the following tables: 30 144310

Table 11A

I / O, 6 equivalent weight ratio Complex concentration: 1 g per ml. 100 ml Calcium concentration: 1000 mg / liter

NaOH (0.25 g per ml) added, ml pH Observations 0 2.15 no precipitate 0.20 2.75 "" 0.40 5.80 "" 0.50 7.85 "" 0.60 9, 40 "" 0.70 10.80 low precipitate

Table 11B

l / l equivalent weight ratio Complex concentration: 1 g / l 100 ml Calcium concentration: 1000 mg / liter

NaOH (0.25 g per ml) added, ml pH Observations 0 2.20 no precipitate 0.20 2.80 "" 0.40 4.05 "" 0.50 7.60 "" 0.60 9, 25 "" 0.70 10.60 "" 0.80 11.20 "" 0.90 11.40 "" 31 144310

Table 11C

1 / 0.6 equivalent weight ratio Complex concentration: 1 g per 100 ml Calcium concentration:. 1500 mg / liter

NaOH (0.25 g per ml) added, ml Observations 0 2.20 no precipitate 0.2. 2.85 "" 0.4 5.50 "" 0.5 7.80 "" 0.6 9.40 "" 0.7 10.70 low opalescence 0.8 11.20 "" 0.9 11, 40 cloudiness 1.0 11.45 coagulate formation.

Table IIP

l / l equivalent weight ratio Complex concentration: 1 g / l 100 ml Calcium concentration: 1500 mg / liter

NaOH (0.25 g per ml) added, ml pH Observations 0 2.20 no precipitate 0.20 2.60 "" 0.40 4.00 "" 0.50 6.50 "" 0.60 8, 80 "" 0.70 10.70 "" 0.80 11.10 "" 0.90 11.55 "" 1.00 11.45 "" 144310 32

Table HE

l / l equivalent weight ratio Complex concentration: 1 g / l 100 ml Calcium concentration: 2000 mg / liter

NaOH (0.25 g per ml) added, ml pH Observations 0 2.15 no precipitate 0.20 2.70 "" 0.40 4.30 "" 0.50 7.40 "" 0.60 9, 25 "" 0.70 10.55 "" 0.80 11.10 "" 0.90 11.40 "" 1.00 11.50 'cloudy

After the developed cloudiness in this test, an additional 1 g of the complex was added to the system, and the cloudiness completely redissolved. An additional 0.70 ml of sodium hydroxide was used to raise the pH from 6.4 back to 11.35, observing a poor opalescence.

Table 11F

1 / 0.6 equivalent weight ratio Complex concentration: 1 g per 100 ml Calcium concentration: 2000 mg / liter

NaOH (0.25 g per ml) added, ml pH Observations 0 2.30 no precipitate 0.20 3.10 "" 0.40 5.70 "" 0.50 7.80 "" 0.60 9, 50 "" 0.70 10.80 cloudiness 0.80 11.15 "0.90 11.40 precipitation 33 334310

Table 11G

l / l equivalent weight ratio Complex concentration: 1 g / l 100 ml Calcium concentration: 2500 mg / liter

NaOH (0.25 g per ml) added, ml pH Observations 0 2.20 no precipitate 0.2 2.80 "" 0.4 4.00 "" 0.5 6.30 "" 0.6 8, 85 "" 0.7 10.00 "" 0.8 11.00 "" 0.9 11.30 "" 1.0 11.45 obscurity.

Table 11H

l / l equivalent weight ratio Complex concentration: 1 g / l 100 ml Calcium concentration: 3000 mg / liter

NaOH (0.25 g per ml) added, ml pH Observations 0 2.20 no precipitate 0.2 2.80 "" 0.4 4.20 "" 0.5 6.90 "" 0.6 9, 45 M "0.7 10.50" "0.8 11.10 Opalescence 0.9 11.35 Precipitate 34 144310

Example XII

Experiments were performed as in Example XI to determine the effect of calcium ion contamination in an aqueous alkaline system containing aluminum lignosulfonate complexes prepared in accordance with the teachings of U.S. Patent No. 2,771,421. An aluminum lignosulfonate / oxalic acid material was prepared by heating to 80 ° C with stirring 333.33 g of a 32 wt% calcium ligno sulfonate solution containing 5.6 wt% calcium and 62.2 wt% lignin. 33.23 g of aluminum sulphate having a sulphate = equivalent to the amount of calcium present in the lignosulphonate were added over about 30 minutes. 2 minutes. Then, 10.22 g of oxalic acid equivalent to 11% of the weight of the lignin present was added. Then the sample was filtered through "Munktell" No. 006 filter paper and was found to contain 26.8% by weight solids and spray dried. A second sample was prepared by complexing aluminum sulfate with calcium lignosulfonate as indicated above and subsequent addition of 7.30 g of citric acid, equivalent to 11% by weight of the lignin present. The sample was stirred at 80 ° C for approx. 20 minutes and filtered as above and spray dried. The sample contained 23.8% solids. 2 g of the aluminum lignosulfonate / oxalic acid complex was added to a 6% sodium chloride aqueous system. 50 ml of this solution was mixed with 50 ml of a 2000 ppm calcium ion solution to prepare a solution containing 1 g aluminum lignosulphonate / oxalic acid complex, 3% sodium chloride and 1000 ppm calcium ion. This solution was placed in a magnetic stirrer and increasing amounts of a 1 ml of 0.25 g sodium hydroxide containing solution were added by means of a microburette. The results were as follows:

hl '

""

35 14 A310

Table 12A

Aluminum lignosulfonate / oxalic acid complex 1 g, 3% NaCl and 1000 ppm Ca ++

NaOH added, ml (1 ml = 0.25 g NaOH) pH Observations 0 2.65 clear 0.12 5.50 cloudy 0.15 8.60 precipitate 0.20 9.65 strong precipitate 0.30 11.10 " "0.35" 11.20 "" 0.40 11.35 "" 0.50 11.50 ""

The resulting solution was filtered and the filtrate analyzed for soluble aluminum content. Of the 6.94 mg of aluminum originally added, 3.5 mg was found to be soluble. 49.6% of the initially added aluminum amount was separated by the solution.

This experiment was repeated at a calcium level of 2000 ppm. The results are given in Table 12B.

Table 12B

Aluminum lignosulfonate / oxalic acid complex 1 g 3% NaCl, 2000 ppm Ca ++

NaOH added, ml (1 ml = 0.25 g NaOH) pH Observations 0 2.70 clear 0.05 4.45 cloudy 0.10 5.00 "0.15 7.75 heavy precipitate 0.20 9.10" "0.30 10.40" "0.40 10.95" "0.50 11.20" "0.60 11.40" "36 144310

The amount of aluminum remaining in solution was 3.0 mg. 56.8% of the metal ion was precipitated by the solution.

An aluminum lignosulfonate / citric acid complex was similarly investigated. Two similar experiments were performed at a calcium concentration of 2000 mg / liter. The results of this experiment are given in Tables 12C and 12D.

Table 12C

Aluminum lignosulfonate / citric acid complex 1 g, 3% NaCl, 2000 mg / liter Ca ++

NaOH added, ml

Cl ml = 0.23 g NaOH pH Observations 0 2.80 clear 0.10 5.40 "0.20 9.10 opalescence 0.30 10.90 vigorous precipitation 0.40 11.20" "0.50 11 , 30 "" 0.60 11.40 "" 0.70 11.50 "" 0.80 11.55 ""

The dissolved aluminum content was found to be 1 mg. 85.6% of the added aluminum was precipitated by the alkaline solution.

37 144310

Table 12D

Aluminum lignosulfonate / citric acid complex 1 g, 3% NaCl, 2000 mg / liter Ca ++

NaOH added, ml (1 ml = 0.25 g NaOH) pH Observations 0 3.00 clear 0.10 5.00 "0.15 8.12" 0.20 7.50 cloudy 0.25 10.50 clear precipitate 0.30 11.90 Heavy Precipitate 0.35 11.10 "" 0.45 11.30 "" 0.50 11.40 "" 0.60 11.45 "" 0.70 11.55 ""

The dissolved aluminum amount was 1.2 mg. 82.8% of the added aluminum was precipitated by the solution.

An aluminum sulfate / citric acid complex at a 1-to-1 equivalent weight ratio that did not contain lignosulfonate was subjected to the same experiment as given in Tables 12C and 12D. The results of this experiment showed that the substance which did not contain lignosulfonate yielded a complex which was not precipitated by the solution, thus showing that the presence of lignosulfonate yields a less effective material.

Table 12E

Aluminum / citric acid complex 1 g 3% NaCl, 2000 ppm Ca ++

NaOH added, ml (1 ml = 0.25 g NaOH) pH Observations 0 2.20 clear 0.10 2.38 "0.20 2.80" 38 144310 (Table 12E continued)

NaOH added, ml (1 ml = 0.25 g NaOH) pH Observations 0.30. 3.00 clear 0.40 7.10 "0.50 7.95" 0.60 11.02 "0.65 11.45 cloudy

It should be noted that the turbidity noted at pH 11.45 disappeared upon standing for approx. for an hour to get a clear solution. As lignosulfonate was not present in this case, the amount of aluminum added was 15.0 mg. The sample was filtered after alkali treatment as given in Table 12E and the filtrate was analyzed for aluminum content. It was found that the filtrate contained 15.0 mg of Al, showing that the complex was 100% soluble and that none of the metal ion had precipitated from the solution.

Example XIII

As previously stated, U.S. Patent No. 2,771,421 discloses the use of aluminum lignosulfonate complexes as drilling fluid additives. This doctrine deals with a calcium lignosulfonate treated with aluminum sulfate. Oxalic acid or a related organic acid is then added. Although the known material contains to a certain extent the "same starting materials used in the present complexes, it is believed that the known material is quite different from the present complexes. For example, the lignosulfonate acts primarily as a dispersant, rather than Furthermore, since lignosulfonate can prevent complete complexation of the metal ion, this drilling fluid would likely give an aluminum precipitate at pH values above about 10.0, especially in environments with a high calcium ion content. the fact that in this known material, aluminum complex is obtained partly with lignosulfonate and partly with an IQ acid, the method of the present invention utilizes a metal ion which has completely formed a complex with the acid or a salt thereof, rather than down It is believed that this difference in the complex structure makes the process of this invention more effective in inhibiting qu aging of clay slate, similar to a method using it in the U.s. The patent relates to lignosulf onat drilling fluid.

An experimental lignosulphonate complex containing citric acid was prepared for experimental purposes. It was prepared by complexing 33.23 g of aluminum sulfate with 32% calcium lignosulfonate, 5.6 wt% calcium and 62.2 wt% lignin, and then 7.30 g citric acid, corresponding to 11 wt% of the lignin present, was added. The sample is stirred at 80 ° C for approx. 20 minutes and filtered. This sample contained 25.8% solids. The precipitate was removed by filtration and the filtrate was spray dried. An aluminum sulfate / citric acid complex having a 1-to-1 equivalent weight ratio as described in Example I. was also prepared. These samples were tested for inhibition of 9% hydrated sodium bentonite suspensions using a post-treatment process. Samples were tested at a treatment level of 5 g. After the sample was added, the pH was adjusted to 9.5. The flow properties were measured, initially, and partly after hot rolling at 67 ° C for 16 hours, and after adjusting the pH to approx. 9.2. The results of this experiment showed that the aluminum sulphate / citric acid complex, which did not contain lignosulphonate, was more effective as a hydration slate aftertreatment inhibitor at a treatment level of 5 g. The results of this experiment were as follows:

Table 13

Degrees Found at the following rpm (outer cylinder).

600 300 200 100 6 3 pH

5 g Mmdnium lianosilphsate + 142 87 64 39 6 4 9.3 citric acid, initially 5 g Murrunium lignosilphonate + 215 149 120 81 22 18 7.9 citric acid, hot-rolled 5 g Muminium lignosulfonate + 200 137 107 69 12 9 9.2 citric acid, pH adjusted 40 144310 (Table 13 continued)

Degrees Found at the following roundabout. per. mine. (outer cylinder) 600 300 200 100 6 3 pH

5 g aluminum sulphate / citric acid, initially 78 44 32 18 2 1 9.4 5 g aluminum sulphate / citric acid, hot-rolled 150 100 79 53 13 H 8.3 3 g aluminum sulphate / citric acid, pH adjusted 151 97 76 49 9 7 9.2

Blank sample, initially 235 176 149 115 54 50 9.2

Blank sample, hot-rolled> 300 286 249 200 102 95 8.8

Blank sample, pH-adjusted> 300 238 201 155 71 66 9.5

Example XIV

In this example, an aluminum sulfate / lignosulphate complex containing citric acid and prepared as in Example XIII was compared with a 1-to-1 equivalent weight ratio of aluminum sulfate / citric acid complex in an experiment to determine the erosion properties of liquids which containing a "gumbo" Clipper Slate and the Complex Compounds. "Gum Bomb Slices" were prepared by pressing 100 g of "gumbo" in a 53 mm disc press at a pressure of 430 kg / cm, maintaining the pressure for 2 hours. The test discs were removed and subjected to a relative humidity of 98% for 72 hours. A recirculating system for circulating the sample liquid containing the selected complex was used against the surface of the disc at a rate of 145 ml / sec. through a 1 cm opening which was placed 13 mm above the specimen. The temperature of the circulating liquid was 42 ° C. In this way, 4 special liquids were tested against 4 slices. The first liquid (liquid 1) contained only tap water with a pH of 9.3. The second liquid (liquid 2) contained tap water and 5 g of the aluminum lignosulfonate complex at pH 9.3. The third sample (liquid 3) contained tap water and 5 g of aluminum sulfate / citric acid complex adjusted to pH value A 9.3 This experiment showed that the aluminum sulfate / citric acid complex treated slab is degraded substantially less than the slice containing aluminum = lignosulfonate additive. The results are given in the following table:

Table 14 Liquid Effect on the Disc 1 The liquid cuts a hole through the sample over 20 minutes. After 60 minutes, the hole had a diameter of approx. 40 mm. Only one edge of the original slice was left after the end of the trial period.

2 After 100 minutes, the surface breaks down in the middle and on the edges.

3 Slight erosion at the disc edge after 100 minutes. Example XV

A basic sludge containing 10 kg / ml was prepared. 400 liters of pre-hydrated sodium bentonite and 0.5 kg per liter. 400 liters of carb = oxymethyl cellulose in tap water. Samples of this basic sludge were treated with 5 kg per day respectively. 400 liters of drywall, 10.5 kg per

400 liters of potassium chloride, 14.0 kg per 400 liters of "Nepturi" sea salt and 5 kg per 400 liters of an aluminum sulfate / citric acid complex in a 1-to-1 equivalent weight ratio. The samples were stored for about 16 hours at 67 ° C in a rotary kiln. The concentration of the complex in the filtrate was determined at 2.2 kg per 400 liters after hot rolling, and an additional 2.8 kg per 400 liters of the complex metal ion material was added to the sample to maintain 5 kg per 400 liters of concentration. , originating from an oil well near Eugene Island at Loui-

ISLAND

the coast of Siana, by subjecting the clay skiff to a pressure of 430 kg / cm in a Carver press. The pieces were cut into pieces, added to the samples and hot rolled for 1 hour. After hot rolling, the samples were removed, sieved through a standard frame screen, and photographed at magnification for comparison. The results of this experiment are given in Figures 1-6.

42 1 <443 1 O

Brief Description of Figures 1-6

FIG. 1 shows the formation fragments after being subjected to pressure and then cut to resemble formation chips.

FIG. 2 shows the chips in the base mud after the sample. You can clearly see the swelling of the chips.

FIG. 3 shows the chips that have been exposed to the sample treated with the metal ion complex. The large amount of rubbery material seen in FIG. 2, you don't see here.

FIG. 4 shows results obtained by a plaster treatment. Although the chips here may be in a somewhat dispersed state, there is still context.

FIG. 5 shows the results obtained with potassium chloride. Here one sees more dispersion than in fig. 4th

FIG. 6 shows treatment with "Nepturt" sea salt. There is a clear accumulation and dispersion here.

Example XVI

The procedure shown in Example XV was followed but the compressive compression pressure was reduced to 290 kg / cm to determine the complex's ability to prevent congruent clumping of a softer formation chip. The results showed that the complex was effective in preventing clumping of the chips. FIG. 7-9 shows the test results.

Brief Description of Figures 7-9

FIG. 7 is the image of the base mud after the sample. Notice the aggregation of the material.

Figure 8 is a drawing illustrating plaster. Here it is clearly seen that, although there has been some degradation of the material, there is essentially only a single mass of material.

FIG. 9 is a drawing of the sludge containing the complexed substance. Note the lack of chip buildup.

Example XVII

The procedure used in Example XV was used with the following metal ion complexes: 1) Aluminum sulfate / tartaric acid (1.0 / 0.5 equivalent weight ratio) 2) Aluminum sulfate / potassium bitartrate (1.0 / 0.5 equivalent weight ratio) 3) Ferric chloride / citric acid (1.0 / 1.0 equivalent weight ratio) 4) Lantern nitrate / citric acid (1.0 / 1.0 equivalent weight ratio) 5) Aluminum sulphate / sodium citrate (1.0 / 1.0 equivalent weight ratio).

All samples satisfactorily demonstrated the ability to prevent bulging of the formation chips in question.

Example XVIII

An experiment was initiated during drilling operations at a Louisiana platform off the coast. The following aqueous drilling fluid systems were prepared, using borehole water from the borehole during drilling of the conduit hole: 400 liters of sodium bentonite 2. 0.5 kg per 400 liters of sodium hydroxide 3.3 kg 400 liters of chromium lignosulfonate 4.5 kg per 400 liters of aluminum sulfate / citric acid complex (1-to-1 equivalent weight ratio) 400 liters of carboxymethyl cellulose 6. Baryte added to ensure 10.5 kg / ml. The 400 liter system.

The pH of the sludge was adjusted from 6.5 to approx. 8.5 · A freshwater gel drilling fluid was replaced in the conduit hole with the aforementioned aqueous liquid.

"" 'H