Untitled record

full description

Sister Ra'a wallpaper

This invention relates to high density aqueous brines suitable for use as well fluids.

Conventional aqueous brine fluids, such as bromide, are used

<p>5 Calcium bromide, which can have densities of about 1.70 kg/L, is widely used in oilfield production as clear completion fluids, drilling fluids, packer fluids, etc. For some wells, downhole pressure values ​​can be as high as 2.1 x 108Pa (30,000 psi). These higher pressure values ​​occur at least downhole</p>

<p>10 In the Gulf of Mexico, temperatures at the mud line in the Gulf of Mexico can reach 44.4 °C. As a general note, each 6.9 x 107 Pa (10,000 psi) increase in pressure can increase the aqueous brine crystallization temperature by about 5.6°C.</p>

Typical aqueous brine fluids include calcium bromide, which has

<p>15th Densities of about 14.2 pounds per gallon (1.70 kg/L). The calcium bromide aqueous brine has a density of about 14.2 pounds per gallon (1.70 kg/L) and has an actual crystallization temperature of less than -12.2°C. However, aqueous brine solutions can be formed from calcium bromide that have densities as high as 15 pounds per gallon (1.8 kg/L); these solutions have an actual crystallization temperature of about</p>

<p>20 61 F (16.1 C). These aqueous brines are not calcium bromide </p>

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The higher density is suitable for use in some downhole applications, such as those often found in the Gulf of Mexico, because sedimentation products will form in these aqueous brine solutions of higher density calcium bromide due to their relatively high actual crystallization temperatures.

<p>5 Aqueous brine solutions of calcium bromide containing zinc with a high density, for example, about 14.5 pounds per gallon (1.74 kg/L) or greater, are easily obtained by mixing sufficient bromide and zinc in an aqueous brine of calcium bromide to reach Calcium bromide brines containing zinc have actual crystallization temperatures of about 20°F.</p>

<p>10 (-6.7 °C) or less, making these zinc brines more suitable</p>

For downhole use. However, inclusion of zinc requires greater reporting to government agencies of environmental causes, which results in more costly environmental mitigation measures. For example, zinc is regulated as a priority pollutant by the US Environmental Protection Agency

Protection Agency . (EPA).

<p>15th Thus, there is a need to develop high-density aqueous brine fluids that are zinc-free, and that have actual crystallization temperatures that are appropriately low for downhole use.</p>

General description of the invention

This invention provides aqueous brine solutions of high density and low crystallinity temperature of 20 that are zinc-free. It has also been discovered, for example, that aqueous brine can be prepared

A zinc-free, high-density mixture of water and two or more inorganic bromide salts wherein the inorganic bromide salts include calcium bromide and cesium bromide. These brine solutions can exhibit densities of about 15.0 pounds per gallon (1.80 kg/L) or greater, and have

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With crystallization temperatures of about 20 F (-6.7 C) or less, often around

<p>15th Fahrenheit (-9.4 °C) or less. These brines are suitable for use as borehole fluids, such as completion fluids, particularly pure completion fluids, drilling fluids, filler fluids, maintenance fluids, and other fluids that use aqueous brine, in particular brines. aquatic</p>

<p>5 of high density. The aqueous brine solutions according to this invention are well suited for offshore upgrading activities involving high pressure reservoirs, such as the oil and gas fields in the Gulf of Mexico.</p>

One embodiment according to this invention is a zinc-free aqueous brine formulation. Formula has a density of approximately 14.3 pounds per gallon (1.71 kg/L) to approximately 15.8 pounds per gallon

<p>10 (1.89 kg/L), the actual crystallization temperature is about 20 F (-6.7 C) or</p>

s lower, preferably about 15 F (-9.4 C) or less, and include water, calcium bromide, and cesium bromide. Processes to create these aqueous brine formulations are also offered.

Such models, models and other features according to this invention will be further evident from the following description and 15 numbers of protection elements attached.

Detailed description:

As used throughout this document, the term "zinc-free" means that except for adventitious impurities, neither zinc nor zinc compounds are present in, or incorporated into, compositions or processes in accordance with this invention. Generally speaking, there are about 25 parts in

<p>20 1 million or less zinc present in aqueous brines according to this</p>

Sister, take care.

The term ppm means parts per million (w/w), as used throughout this document, unless specifically stated otherwise in this order. Throughout this document, both “lbs per gallon” and “lbs/gallons” mean Abbreviations for pounds per gallon.

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“TCT” stands for true crystallization temperature (or true crystallization point) as used throughout this document. The actual crystallization temperature is the temperature at which the precipitate begins to form in the absence of Supercooling A method for determining the actual crystallization temperature is described in this application 5 below.

The terms “inorganic bromide salt”, “inorganic bromide”, and “bromide salt” are used interchangeably throughout this document.

Where the compositions according to the invention can be used as clear completion fluids, the precipitation and/or 10 degree fuzziness in aqueous brine solutions according to the invention are undesirable. To be suitable for use as well fluids, aqueous brine solutions of the invention have little or no sedimentation formation over time (eg, approximately one week) at ambient temperature and pressure eg, 17 to 25 °C and 0.1 MPa to 0.11 MPa or at high temperature, for example, about 60°C and ambient pressure.

<p>15th The compositions according to the invention are aqueous brine solutions comprising one or more inorganic bromide salts other than zinc bromide. Although it is convenient to refer to compounds of bromide salts, metal cations, and bromide anions, species in compositions can form complexes with water, or in some other specific form. Likewise, any other inorganic salts are soluble in water</p>

<p>20 They are included in aqueous brines according to the invention which are referred to as salts or their corresponding cations and/or anions may form complexes with water, or in some other specific form.</p>

In the process of applying this invention, the inorganic bromide salt is selected from calcium bromide and cesium bromide. One or more other water-soluble inorganic salts may be used, preferably selected from the inorganic bromide salt.

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When the inorganic salts of the aqueous brine are formed only from the inorganic bromide salts, the total amount of the inorganic bromide salts in the aqueous brine is typically in the range from about 50wt to about 60wt%, relative to the total weight composition. The preferred total amounts of the inorganic bromide salts range from about

<p>5 53 by weight to approximately 58 by weight, relative to the total weight of the formula.</p>

The compositions according to the invention have densities of approximately 14.3 pounds per gallon (1.71 kg/L) to

Approx. 15.8 pounds per gallon (1.89 kg/L). Preferably, formulations have densities of approximately 14.6 pounds per gallon (1.75 kg/L) or more. In some embodiments, fixtures preferably have densities of approximately 14.8 pounds per gallon (1.77). kg/L (or more, or as

<p>10 Preferably about 15.0 pounds per gallon (1.80 kg/L) or more, or more preferably about 15.1 pounds per gallon (1.81 kg/L) or more.</p>

Density ranges for formulations according to this invention preferably from about 14.3 pounds per gallon (1.71 kg/L) to about 15.8 pounds per gallon (1.89 kg/L), more preferably about 14.6 pounds per gallon (1.75 kg/L) To about 15.6 pounds per gallon

<p>15th (1.87 kg/L). In some embodiments, preferred densities range from about 14.8 pounds per gallon.</p>

(1.77 kg/L) to about 15.4 pounds per gallon (1.85 kg/L), more preferably about 15.0 pounds per gallon (1.80 kg/L) to about 15.6 pounds per gallon (1.87 kg/L).

For compositions according to the invention, actual crystallization temperatures are reached

<p>20 . Generally about 20 F (-6.7 C) or less, preferably around</p>

15th Fahrenheit (-9.4 C) or less, more preferably about 10 F (-12.2 C) or less, and still more preferably about 5 F (-15.0 C) or less.

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Aqueous brine formulations according to the invention naturally have pH values ​​of about 2 or more, preferably about 4 or more, and may range from about 2 to about 10. Preferred pH values ​​are in the range of about 4 to about 8; More preferably the pH values ​​are in the range from about 6 to about 5 8.

As is known in the art, it is often advantageous to include one or more optional additives in aqueous brine, and the inclusion of such additives is within the scope of this invention. Optional additives may include, for example, corrosion inhibitors, lubricants, pH control additives, 10 surfactants, and/or solvents. solvents

In some preferred zinc-free aqueous brine formulations of the invention, only water, inorganic bromide salts, and one or more other water-soluble inorganic salts, and species derived from these components, are present in the composition; In these preferred embodiments, the inorganic bromide salts include calcium bromide and cesium bromide.

.bromide 15

In other preferred zinc-free aqueous brine formulations according to the invention, only water, inorganic bromide salts, and species derived from these ingredients are present in the composition; Inorganic bromide salts include calcium bromide and cesium bromide.

Preferred compositions according to this invention include zinc-free aqueous brine solutions comprising 20 water, calcium bromide, and cesium bromide; The formula has a density of about 14.3 .

pounds per gallon (1.71 kg/L) or more, preferably about 14.6 pounds per gallon (1.75 kg/L) or more, more preferably about 15.0 pounds per gallon (1.80 kg/L) or more; actual crystallization temperature About 20 F (-6.7 C) or less, preferably about 15 F (-9.4 C) or less, more preferably around

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<p>10 Fahrenheit (-12.2 °C) or less. In these formulations, the calcium bromide is preferably in an amount ranging from about 45 wt% to about 60 wt%, relative to the total weight of the formulation. In these formulations the cesium bromide is preferably in an amount ranging from from about 3.0 wt% to about 15 wt%, preferably about 3 wt% to about 12 wt%,</p>

<p>5 relative to the total weight of the composition; Preferably, these compositions have a pH in the range of about 4 to about 8, more preferably about 6 to 8.</p>

In a preferred embodiment, the inorganic bromide salts are calcium bromide and cesium bromide, the composition has a density of about 14.6 pounds per gallon (1.75 kg/L) or more and an actual crystallization temperature at an atmospheric pressure of about 20 F (-6.7 °C) ( or

<p>10 Less, preferably about 15 F (-9.4 C) or less. Formulations containing calcium bromide and cesium bromide having densities of about 15 lbs/gallon (1.8 kg/L) to 15.6 lbs per gallon (1.87) are particularly preferred. kg/L), and actual crystallization temperatures at atmospheric pressures of about 15 F (-9.4 C) or less, more preferably about 10 F (12.2 C) or less. Preferably, these have</p>

<p>15th Formulations containing calcium bromide and cesium bromide have pH values ​​in the range of about 4 to 8, more preferably around 6 to 8.</p>

Zinc-free aqueous brine solutions having a density of about 14.3 pounds per gallon (1.71 kg/L) or more and an actual crystallization temperature of about 20 F (-6.7 C) or less are formed by processes involving incorporation, in any order , components that include

<p>20 Water and two or more inorganic bromide salts, wherein the inorganic bromide salts include calcium bromide and cesium bromide.</p>

The incorporation of water and inorganic bromide salts may be carried out by any method used to mix inorganic salts and water. Naturally and preferably, concentrated solutions of inorganic salts may be mixed with the addition or removal of water to provide the desired composition. Alternatively, salts are added

<p>25 Inorganic bromide to water. Inorganic bromide salts can be mixed with part of the water before</p>

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To be combined with each other and, when needed, more water. When co-feeding components or mixtures thereof, there is no need for the feed streams to be fully co-extended over time, and each feed stream can be stopped at one or more points during the co-feeding. Another preferred method of operation is to introduce one or more inorganic 5-bromide salts as a solid into a pre-formed aqueous solution of the inorganic bromide salts.

other. A combination of methods can be used if desired.

One or more inorganic bromide salts can be formed during the process. The formation of the inorganic bromide salt may be used during the process to form part, or all, of the inorganic bromide salt. When the inorganic bromide salt is formed during the process, it may be formed in water before some or all of the other inorganic bromide compounds are introduced, or, preferably, into a solution

Aqueous bromides (bromide compounds) other inorganic.

The inorganic bromide salt can be formed during the process in various ways. In some embodiments, the inorganic bromide salt can be formed from the metal in the elemental form and elemental bromine (Br2) (elemental bromine), particularly where the metal is calcium.

<p>15th In other embodiments, the inorganic bromide salt may be formed from inorganic oxide and/or hydroxide</p>

Be a bromide source and an organic inorganic oxide and/or hydroxide bromide

Hydrogen bromide and/or elemental bromine. In preferred embodiments, the inorganic bromide salt is formed from (1) inorganic oxide and/or hydroxide and (2) hydrogen bromide

<p>20 hydrogen bromide and/or bromine.</p>

Inorganic oxides and/or hydroxides which may be used to form the inorganic bromide salt during the process include one or more calcium oxide and/or hydroxide, cesium oxide and/or /or hydroxide, or mixtures of any two or 25 more of the above.

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When one or more inorganic oxides and/or hydroxides are used, the bromide source for the formation of inorganic bromide during the process is hydrogen bromide, bromine, or a mixture thereof. Preferably, the bromide source is hydrogen bromide or a mixture of hydrogen bromide and bromine; more

<p>5 Preferably it is a mixture of hydrogen bromide and bromine. In these mixtures, the hydrogen bromide and bromine may be in any desired proportions ranging from 100% hydrogen bromide to 100% Br2, or in any proportion between them. For convenience, it may be desirable to use a mixture in which hydrogen bromide is present. When bromine (elemental bromine) is used, there is also a reducing agent, either alone or in combination with hydrogen bromide,</p>

<p>10 It is typically methanol, ethanol, formic acid, hydrazine, and the like.</p>

When forming a zinc-free aqueous brine according to the invention, the calcium bromide is typically in quantity in the range from about 45% by weight to about 60% by weight, preferably about 45% by weight to about 55% by weight, relative to total weight

<p>15th The composition of the aqueous brine that is formed. Preferred amounts of cesium bromide in the aqueous brine range from about 3 wt% to about 15 wt%; More preferably about 3 wt% to about 12 wt%, relative to the total weight of the formulation.</p>

When an inorganic bromide salt is formed during the process, the amount of that inorganic bromide salt is calculated as if the inorganic bromide salt was added. Amounts of salt will vary

<p>20 Inorganic bromide, based to some extent on the amount(s) of other inorganic bromide(s), because less inorganic bromide salt is required to reach a specific density value as the amount of other inorganic bromide salt(s) increases.</p>

The amount of water and/or inorganic bromide salts used to form the aqueous brine solutions can be adjusted according to the invention to reach the desired density. Water removal can be used, for example

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eg by heating and/or vacuo, to reach the desired density of zinc-free aqueous brine composition.

The zinc-free aqueous brine can be heated while the components are combined and/or after the components have been combined, to ensure that the components are dissolved. In this optional heating step, the mixture is formed while

<p>5 The process and/or the aqueous brine formed by the process is heated at a temperature of about 40°C or higher to form a heated solution. Higher temperatures can increase the rate of dissolution of the inorganic bromide salt(s). These higher temperatures for heating the aqueous brine are typically in the range of about 40°C up to the boiling point of the mixture, preferably around 45 Celsius to about 100 Celsius,</p>

<p>10 More preferably around 50°C to about 95°C, and more preferably around 60°C to about 95°C. In some embodiments, it is preferable to operate under higher pressure, typically around 105 x 1.4 to 105 x 2.77 Pa, because higher temperatures can be obtained. When the aqueous brine is cooled to ambient temperatures (typically about 15°C to about 25°C, often around 17</p>

<p>15th °C to about 23 °C), the inorganic bromide salt(s) usually remain undissolved.</p>

Optionally, the pH of the zinc-free aqueous brine can be adjusted by adding an acid or base as needed. Suitable acids include mineral acids and water-soluble organic acids; Suitable bases are usually oxides and/or compounds

<p>20 Inorganic hydroxide. In some cases, when an inorganic oxide and/or hydroxide is introduced into the zinc-free aqueous brine, a precipitation product is obtained that can form; After filtration, clear aqueous brine.</p>

For pH adjustment, suitable inorganic oxides and hydroxides including oxides and hydroxides of calcium and cesium may be used,

<p>25 Alkali metals including lithium, sodium, and potassium</p>

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potassium, alkaline earth metals, and mixtures of any of these oxides and/or hydroxide compounds. Preferred inorganic oxides and hydroxides include those of calcium and cesium. In some preferred embodiments, the inorganic oxide(s) and/or hydroxides contain one or more of the

<p>5 The same cations that are already in the aqueous brine. In some embodiments, a small amount of precipitate is formed when an inorganic oxide and/or hydroxide is used to increase the pH. Once the precipitate has been removed, eg by filtration, no additional precipitate formation usually occurs.</p>

Acids suitable for pH adjustment include mineral acids and organic acids 10 that are soluble in water. Suitable mineral acids include hydrogen chloride

hydrogen chloride, hydrogen bromide, hydrogen iodide, nitric acid, sulfuric aci, phosphoric acid, and the like. Suitable organic acids include formic acid, tartaric acid, citric acid, 15 gluconic acid, lactic acid, malic acid.

, maleic acid, malonic acid, oxalic acid, and the like. Mixtures of any two or more acids may be used if desired. Hydrogen bromide is a preferred acid, and can be used in a gaseous form, or, preferably, as an aqueous solution.

<p>20 Any optional additives included in the aqueous brine may be introduced by any of the methods in which the inorganic bromide salts are introduced, or by any other appropriate method.</p>

Under storage conditions, aqueous brines having a density of about 15.0 pounds per gallon (1.80 kg/L) or greater often form a precipitate. Stabilization of these thick aqueous brines can be accomplished by adjusting the pH of the aqueous brine. The number value is adjusted

<p>25 hydrogenation by addition of hydroxide and/or inorganic oxide and/or by addition of an acid, </p>

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preferably hydrogen bromide, usually to a value in the range of about -2 to about 10, more preferably about 4 to about 8; Still more preferably around 6 to about 8.

It has been discovered that reducing the pH of aqueous brine formulations can reduce or prevent

<p>5 Additional composition of the precipitation product in aqueous brine. In these cases, the pH can be adjusted as described above.</p>

In some preferred processes according to this invention, only water and two or more inorganic bromide salts are combined to form zinc-free aqueous brines according to this invention.

In some of the preferred processes according to this invention, only water, unsalted bromide salts are incorporated

<p>10 inorganic oxides and/or hydroxides, and/or hydrogen bromide and/or bromine to form zinc-free aqueous brines according to this invention.</p>

Preferred processes according to this invention include the incorporation, in any order, of components comprising water and two or more inorganic bromide salts comprising calcium bromide and cesium bromide.

<p>15th The formed composition has a density of about 14.3 pounds per gallon (1.71 kg/L) to about 15.8 pounds per gallon (1.89 kg/L), preferably about 14.6 pounds per gallon (1.75 kg/L) or more; crystallization temperature Actual is about 20 F (-6.7 C) or less, preferably about 15 F (-9.4 C) or less. In some embodiments, component formulations preferably have densities of about 14.8 pounds per gallon</p>

20 (1.77 kg/L) or more, or preferably about 15.0 pounds per gallon (1.80 kg/L) or

more, or more preferably about 15.1 pounds per gallon (1.81 kg/L) or more. The cesium bromide salt is usually in an amount ranging from about 3.0 wt% to about 15 wt%, preferably about 3 wt% to about 12 wt% , relative to the total weight of the constituent composition.

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In some preferred processes, water and inorganic bromide salts are combined to form an aqueous solution. In other preferred processes, one or more inorganic bromide salts are formed during the process from hydrogen bromide and/or bromine, oxide and/or inorganic hydroxide. The inorganic oxide and/or hydroxide is preferably selected from the oxides and/or hydroxide compounds of

<p>5 Calcium, cesium, and mixtures of any two or more of the above.</p>

Optionally, the processes also include heating the aqueous brine during and/or after incorporating the components; The temperatures and their preferences shall be as described above.

These preferred processes also include adjusting the pH to a value in the range that

It varies from about 4 to about 8 by the addition of non-acid and/or oxide and/or hydroxide

<p>10 organic to aqueous brine composition; Preferably, the inorganic oxide and/or hydroxide is an oxide and/or hydroxide of calcium and/or cesium, or mixtures of any two or more thereof. The preferred pH ranges are as described above.</p>

The following examples are represented for illustrative purposes, and no restrictions on the scope of this invention are intended.

In the following examples, the densities of the solutions are determined by the oscillating U-tube method, which, unless otherwise specified, measures the oscillation frequency of the liquid sample.

In the procedure for determination of alternative density, densities were measured using standard inserted cylinders. In this method, a 50 mL graduated cylinder was calibrated using 30,000 g of deionized water. The volume (eg, 29.7 mL) of the scale calibration was recorded on the inserted cylinder. Each fluid sample was weighed, and the density was calculated using the following formula: Density

<p>20 (Garm/ml) = mass (Garm)/Volume (ml), eg mass (Garm)/29.7 ml. For smaller sample volumes, a 10 ml graduated cylinder was calibrated and used in the same way to determine densities.</p>

The actual crystallization temperature assignments in the examples were determined by one of the two procedures described here.

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The traditional procedure. A coated glass tube containing 50 mL of sample was mechanically stirred while it was cooled using a recycling bath containing coolant (eg, glycol). When the sample reached a temperature of about 10°C higher than the temperature Predicted initial crystallization FCTA (first crystal to appear), the sample was cooled at a rate of about 0.5°C/min or a smaller temperature increase until the actual crystallization temperature was observed

TCT (true crystallization temperature). The FCTA was recorded at the lowest temperature reached before sedimentation, and the TCT was recorded at the highest temperature achieved immediately after the start of precipitation. The sample was removed from the recycling bath. and warmed; when all the precipitation was gone, the melt temperature of the last crystal to 10 LCTD( dissolve) was recorded. Each determination was extended using a crystal of silica

50 ≤ (µm silica, ~0.03 gram) per sample.

Action using tools. A sample beaker containing 0.25 mL of sample was placed in

Phase Xi70, Model No. Cloud, Pour, and Freeze Point Lab Analyzer

Technology, Richmond, Canada), and the sample was cooled at 0.5 °C at 15 min until freezing was detected by diffusive light-scattering.

Comparative example 1

Measurements of TCT (true crystallization temperature) were performed on three samples of aqueous solutions of calcium bromide. These samples contained only water and calcium bromide. The results are summarized in Table 1 below.

<p>20 Comparative example 2</p>

Two samples were prepared starting with 50.0 g of an aqueous calcium bromide (CaBr2) solution having a density of 14.2 lbs (1.70 kg/L). To one sample more CaBr2 (4.32 g) was added; to the other sample, bromide was added Zinc 3.19 (ZnBr2) bromide (Gram). The results are summarized in Table 1 below.

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Comparative Example 3: Two samples were prepared starting with 40.0 g of an aqueous CaBr2 solution with a density of 12.8 lbs per gallon (1.53 kg/L). To one sample more CaBr2 was added (13.18 g); to the other sample, 11.90 was added) ZnBr2 (CRM). The results are summarized in Table 1 below.

<p>5 Comparative example 4</p>

A series of samples was prepared starting from 50.0 g of an aqueous CaBr2 solution with a density of .

<p>1 4.2 pounds per gallon (1.70 kg/L). 4.18 LiBr Garm (4.18 LiBr) salts added,</p>

<p>7 10 Garm (SrBr2•6H2O) and BaBr2 (01 Garm) to separate the CaBr2 solution. Testing of samples containing strontium and containing barium was discontinued due to problems in solubility and density.</p>

Another series of samples was prepared, starting with 40.0 grams of an aqueous CaBr2 solution with a density of 12.8 pounds per gallon (1.53 kg/L). Liber salts (15.18 grams), and Magnesium Bromide Hexahydrate (MgBr2•6H2O) were added. () to separate the CaBr2 solution. The test of the sample containing magnesium 15 was discontinued due to problems in solubility and density. The results are summarized in Table 1 below.

Table 1

<tr><td><p>TCTb</p></td><td><p>Density</p></td><td><p>Total amount of bromide</p></td><td><p>Amount of inorganic bromide</p><p>CaBr2a</p></td><td><p>Inorganic bromide compounds</p></td><td><p>Course</p></td><td><p>Example</p><p>Comparison</p></td></tr><tr><td><p>(2.0°C)</p></td><td><p>(1.769 kg/L)</p></td><td><p>56.3</p><p>wt%</p></td><td><p>nothing</p></td><td><p>CaBr2</p></td><td><p>a</p></td><td><p>1</p></td></tr>

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<tr><td><p>(0.5 degrees Celsius)</p></td><td><p>(1.759 kg/L)</p></td><td><p>56.0</p><p>wt%</p></td><td><p>nothing</p></td><td><p>CaBr2</p></td><td><p>NS</p></td><td rowspan="2"></td></tr><tr><td><p>(-4.0°C)</p></td><td><p>(1,747 kg/L)</p></td><td><p>55.4</p><p>wt%</p></td><td><p>nothing</p></td><td><p>CaBr2</p></td><td><p>NS</p></td></tr><tr><td><p>(-5.5 degrees Celsius)</p></td><td><p>(1,742 kg/L)</p></td><td><p>56.9</p><p>wt%</p></td><td><p>nothing</p></td><td><p>CaBr2</p></td><td><p>a</p></td><td rowspan="2"><p>2</p></td></tr><tr><td><p>(&gt; -21.0 degrees Celsius)</p></td><td><p>(1.746 kg/L)</p></td><td><p>56.0</p><p>wt%</p></td><td><p>6.0</p><p>wt%</p></td><td><p>CaBr2</p><p>ZnBr2</p></td><td><p>NS</p></td></tr><tr><td><p>(-3.0°C)</p></td><td><p>(1.753 kg/L)</p></td><td><p>58.5</p><p>wt%</p></td><td><p>nothing</p></td><td><p>CaBr2</p></td><td><p>a</p></td><td rowspan="2"><p>3</p></td></tr><tr><td><p>(&gt; -21.0 degrees Celsius)</p></td><td><p>(1,757 kg/L)</p></td><td><p>57.5</p><p>wt%</p></td><td><p>22.9</p><p>wt%</p></td><td><p>CaBr2</p><p>ZnBr2</p></td><td><p>NS</p></td></tr><tr><td><p>(1.0°C)</p></td><td><p>(1.743 kg/L)</p></td><td><p>56.8</p><p>wt%</p></td><td><p>7.7</p><p>wt%</p></td><td><p>CaBr2</p><p>LiBr</p></td><td><p>a</p></td><td rowspan="2"><p>4</p></td></tr><tr><td><p>(4.0°C)</p></td><td><p>(1.749 kg/L)</p></td><td><p>66.1</p><p>wt%</p></td><td><p>27.5</p><p>wt%</p></td><td><p>CaBr2</p><p>LiBr</p></td><td><p>NS</p></td></tr>

a is relative to the total weight of the solution.

b Actual crystallization temperature; determined by this conventional procedure .

example 1

Several separate samples were prepared starting with aqueous solutions of CaBr2 having a density of 14.2 lb .

5 per gallon (1.70 kg/L) by adding an amount of CsBr to the CaBr2 solution; clear, colorless solutions were formed. A portion of each of some of the samples was placed in a freezing medium at

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-16°C for one week. Two samples were then analyzed to determine their density and actual crystallization temperature (TCT), which was below -20°C. TCT values ​​were determined by the instrumental procedure described above. The results are summarized in Table 2 below.

Table 2

<tr><td><p>TCTb</p></td><td><p>The solution remained clear at -16 °C</p></td><td><p>Density</p></td><td><p>Total amount of bromide</p></td><td><p>Quantity</p><p>CsBra</p></td><td><p>Quantity</p><p>CaBr2a</p></td><td><p>Course</p></td></tr><tr><td></td><td><p>at least one week</p></td><td><p>15.2 pounds per gallon</p><p>(1.825 kg/L)</p></td><td><p>58.1</p><p>wt%</p></td><td><p>10.5</p><p>wt%</p></td><td><p>47.6</p><p>wt%</p></td><td><p>1</p></td></tr><tr><td><p>&gt; -21.3</p><p>Celsius</p></td><td></td><td><p>15.2 pounds per gallon</p><p>(1.825 kg/L)</p></td><td><p>58.1</p><p>wt%</p></td><td><p>10.5</p><p>wt%</p></td><td><p>47.6</p><p>wt%</p></td><td><p>2</p></td></tr><tr><td></td><td><p>at least one week</p></td><td><p>15.4 pounds per gallon</p><p>(1.85 kg/L)</p></td><td><p>59.2</p><p>wt%</p></td><td><p>12.8</p><p>wt%</p></td><td><p>46.4</p><p>wt%</p></td><td><p>3</p></td></tr><tr><td></td><td><p>at least one week</p></td><td><p>15.6 pounds per gallon</p></td><td><p>60.2</p><p>wt%</p></td><td><p>15.0</p><p>wt%</p></td><td><p>45.2</p><p>wt%</p></td><td><p>4</p></td></tr>

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<tr><td></td><td></td><td><p>(1.87 kg/L)</p></td><td></td><td></td><td></td><td></td></tr><tr><td><p>&gt; -22.5</p><p>Celsius</p></td><td></td><td><p>15.6 pounds per gallon</p><p>(1.87 kg/L)</p></td><td><p>60.2</p><p>wt%</p></td><td><p>15.0</p><p>wt%</p></td><td><p>45.2</p><p>wt%</p></td><td><p>5</p></td></tr><tr><td></td><td><p>nothing</p></td><td><p>15.9 pounds per gallon</p><p>(1.90 kg/L)</p></td><td><p>61.2</p><p>wt%</p></td><td><p>17.2</p><p>wt%</p></td><td><p>44.0</p><p>wt%</p></td><td><p>1C c</p></td></tr><tr><td></td><td><p>nothing</p></td><td><p>16.2 pounds per gallon</p><p>(1.94 kg/L)</p></td><td><p>62.8</p><p>wt%</p></td><td><p>20.4</p><p>wt%</p></td><td><p>42.4</p><p>wt%</p></td><td><p>c2C</p></td></tr>

a is relative to the total weight of the solution.

b Actual crystallization temperature; determined by the traditional procedure.

c cycle comparison.

Example 2

<p>5 Several separate samples were prepared by adding CsBr (cesium bromide) to aqueous solutions of CaBr2 having a density of 14.2 pounds per gallon (Doarts A, C and E; 1.70 kg/L) or 14.4 pounds per gallon (Doarts B and D). Density and temperatures were determined for 1.73 kg/L. The FCTA (first crystal to appear) and the melting of the crystal were determined. </p>

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LCTD (last crystal to dissolve) for each solution. The FCTA and LCTD were determined as described above in the conventional TCT procedure. The results are summarized in Table 3 below.

Table 3

<tr><td><p>LCTD</p></td><td><p>FCTA</p></td><td><p>density</p></td><td><p>Total amount of bromide</p></td><td><p>Quantity</p><p>CsBra</p></td><td><p>Quantity</p><p>CaBr2a</p></td><td><p>Course</p></td></tr><tr><td><p>)-16.7</p><p>Celsius(</p></td><td><p>(-17.8 degrees Celsius)</p></td><td><p>(1.75 kg/L)</p></td><td><p>54.1</p><p>wt%</p></td><td><p>4.0</p><p>wt%</p></td><td><p>50.1</p><p>wt%</p></td><td><p>a</p></td></tr><tr><td><p>)-9.7</p><p>Celsius(</p></td><td><p>(-10.7 degrees Celsius)</p></td><td><p>(1.7695 kg/L)</p></td><td><p>54.8</p><p>wt%</p></td><td><p>4.0</p><p>wt%</p></td><td><p>50.8</p><p>wt%</p></td><td><p>NS</p></td></tr><tr><td><p>&lt;</p><p>17.8-(</p><p>Celsius(</p></td><td><p>&lt; 17.8-(</p><p>Celsius(</p></td><td><p>(1.77 kg/L)</p></td><td><p>55.0</p><p>wt%</p></td><td><p>5.9</p><p>wt%</p></td><td><p>49.1</p><p>wt%</p></td><td><p>NS</p></td></tr><tr><td><p>)-10.6</p><p>Celsius(</p></td><td><p>(-11.5 degrees Celsius)</p></td><td><p>(1.79 kg/L)</p></td><td><p>55.7</p><p>wt%</p></td><td><p>6.0</p><p>wt%</p></td><td><p>49.7</p><p>wt%</p></td><td><p>Dr</p></td></tr><tr><td><p>&gt; (-17.8°C)</p></td><td><p>&gt;(-17.8°C)</p></td><td><p>(1.80 kg/L)</p></td><td><p>56.0</p><p>wt%</p></td><td><p>8.0</p><p>wt%</p></td><td><p>48.0</p><p>wt%</p></td><td><p>NS</p></td></tr>

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a is relative to the total weight of the solution.

The constituents referred to by the chemical name or formula are identified anywhere in the specification or its claims, whether referred to by the individual or collective formula, as being present prior to being in contact with another substance referred to by the chemical name or species.

<p>5 chemical (e.g., another component, solvent, or otherwise). It does not matter which of the chemical changes, transformations and/or reactions, if any, occur in the resulting mixture or solution since these changes, transformations, and/or reactions represent The corollary of bringing the components specified together under the conditions for which they are called in accordance with this disclosure The constituents are thus identified as being the principal components to be brought together in connection with the execution of a desirable process or in the formation of a desirable combination.</p>

<p>10 Although the protections in this application hereafter may refer to substances, components and/or principal elements in the present tense ("include", "are to", etc.), the reference is to the substance, component or element Principal as if it existed immediately before it came into contact with, or mixed or mixed with, one or more other principal substances, components and/or constituents in accordance with the present disclosure.</p>

<p>15th A chemical reaction or transformation in the course of the operations of contact, blending or mixing, if carried out in accordance with this disclosure and through the ordinary skill of a chemist, is therefore not of practical interest.</p>

The invention may include, consist, or consist principally of the materials and/or procedures cited in this application.

As used in this application, the term "about" modifies the amount of a major component in

<p>20 Compositions specific to the invention or used in methods according to the invention to variation in the numerical amount that can occur, for example, through standard measurement and liquid handling procedures used to form concentration products or the use of solutions in the real world; through unintentional error in these procedures; by differences in the manufacture, source, or purity of the principal elements used to make up formulations or implement methods; and the like. The term includes about quantities</p>

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which differ due to the different equilibrium conditions of the resulting composition of a given initial mixture. Whether or not modified by the term "about", the claims include equivalent quantities.

Except as expressly indicated, "a" or "an" if used and as used in this application is not intended to limit, and should not be construed as limiting, the description or the element of protection on

<p>5 An individual element that this tool refers to. Rather, the "a" or "an" if used and as used in this application, is intended to include one or more of these elements, unless the text expressly indicates otherwise.</p>

This invention is subject to variation in application. Accordingly, the foregoing description is not intended to limit, and should not be construed as limiting, the invention to the specific representations given in this application 10 above.

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