WO2020257332A1

WO2020257332A1 - Methods and compositions for inhibiting iron sulfide

Info

Publication number: WO2020257332A1
Application number: PCT/US2020/038210
Authority: WO
Inventors: George Murray; Grace FAN; Joseph FAN; Steven Chiang
Original assignee: Nanochem Solutions, Inc.
Priority date: 2019-06-17
Filing date: 2020-06-17
Publication date: 2020-12-24

Abstract

A method and composition for controlling iron sulfide scale in various applications, such as oil and golf course management applications. The composition comprising a carboxylated oligomer structure. The method of controlling scale in the soil can include the use of a polytartaric acid (PTTA) polymer that is added to the soil. The oligomer can be added to the soil at a concentration of about 20 ppm or greater.

Description

METHODS AND COMPOSITIONS FOR INHIBITING IRON SULFIDE

SPECIFICATION

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This Patent Application claims priority to U.S. Provisional Application: 62/862352 filed June 17, 2019, the disclosure of which is considered part of the disclosure of this application and is hereby incorporated by reference in its entirety.

FIELD OF THE INVENTION

[0002] The present invention relates generally to the field of iron sulfide (FeS) scale inhibition. More specifically, the present invention relates to a polymer composition and method for applying the polymer composition to various water sources to inhibit the formation of iron sulfide scale.

BACKGROUND

[0003] In the oil industry, it is known water used during oil production is often rich in many dissolved mineral cation ions (calcium, magnesium, sodium, barium, strontium, zinc, lead and iron), relatively water insoluble mineral precipitates can readily form when anions such as carbonate and sulfate are present. This formation of mineral precipitates can deposit and plug oil drilling equipment, which causes a decrease in flow and production. As such, it is

advantageous to try to reduce the production of mineral scale. This is often difficult as the formation water is often exposed to extreme conditions— both in terms of mineral ions, and in temperature/pressure. With anions such as carbonate and sulfate often present, the formation of insoluble calcium carbonate, calcium sulfate, barium sulfate, strontium sulfate readily occurs. [0004] While these mineral precipitates can cause issues, they are readily mitigated using various polymers both degradable or otherwise. The carbonate and sulfate-based minerals are also fairly soluble in mineral acid solutions that can allow them to be effectively removed retroactively. However, one particular mineral formation that is especially difficult to manage is iron sulfide scale. It has been well-cited in literature that iron sulfide not only adversely affects the performance of wells (like with other scale), but also enhances the corrosion rate of inflicted downhole piping. The presence of iron sulfide particles in the injected water can cause lack of injectivity in power water injectors and water disposal wells. (Nasr-EI-Din, H.A. and Al- Taq, A.A. "Water Quality Requirements and Restoring the Injectivity of Water Disposal Wells." Paper SPE 39487. 1998.) Accumulation of iron sulfide and biomass around downhole screens and perforations can cause loss of productivity of water supply wells. (Nasr-EI-Din, H.A., Rosser, H.R. and Hopkins, J.A. "Stimulation of Water Supply Wells in Central Arabia." Paper SPE 36181. 1996.) Build-up of iron sulfide scale in the tubing an create problems during wireline work and can reduce well deliverability. (Kasnick, M.A. and Engen, R.J. "Iron Sulfide Scaling and

Associated Corrosion in Saudi Arabian Khuff Gas Wells." Paper SPE 17933. 1989.)

[0005] There are various mechanisms that can lead formation of iron sulfide. However, all of these mechanisms require sources of both iron and hydrogen sulfide. Hydrogen sulfide can result from sulfate-reducing bacteria, thermal decomposition of sulfate, or being introduced into the well as in gas lift operations. (Nasr-EI-Din, H.A., Al-Humaidan, A.Y. "Iron Sulfide Scale: Formation, Removal and Prevention." SPE 68315. 2001.) Once both hydrogen sulfide and iron are present, the iron reacts with hydrogen sulfide to form various forms of iron sulfide scale. This scale can quickly build on equipment surfaces and plug wells thereby drastically reducing output. The longer the scale resides in an environment populated with hydrogen sulfide, the more likely it is to turn into a type of scale that is not as soluble in mineral acids. This further inhibits the ability to remove the scale and can often involve both mechanical cleaning, and mineral acid cleaning, along with the combination of surfactants, corrosion inhibitors, friction reducers, and a gelled water solution buffered by sodium carbonate that allows the overall pH of the system to remain in balance, and not further corrode the piping. [0006] Additionally, in the golfing and turf maintenance industry, golf course greens, fairways, and tees, golf courses apply a variety of mineral inputs such as nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, boron, copper, iron, manganese, molybdenum, and zinc. Given the importance of maintaining healthy turf that is green in color, golf course superintendents often apply large amounts of iron due to the need of an iron-based enzyme is required in the plant to product chlorophyll— along with magnesium and a nitrogen-carbon starting material. In an attempt to introduce iron into the turf, iron is often over-applied, which causes excess iron to leach into the ground below the roots. In many cases the form of iron that is applied is often ferrous-sulfate based, which adds sulfur to the soil as well. The sulfate- reducing bacteria can create hydrogen sulfide gas from sulfates through their metabolic processes. The production of hydrogen sulfide gas can create insoluble iron sulfide deposits in the soil, which can create a layer in the soil known as "black layer." This layer of soil, rich in iron sulfide deposits, is known for being anaerobic, and lacks the ability to effectively allow water to drain through the profile. This creates a layer where roots cannot grow, and water cannot penetrate, which can eventually jeopardize the health of the entire stand of turf. The current solution to this problem is to renovate the area, whereby all of the turf and soil are removed, and new soil and/or sand is introduced, and new grass is grown in place. This creates additional cost and down time in use of the desired area.

[0007] Because iron sulfide can create issues in both water supply lines and wells, and in the soil, there exists a need to prevent the scale from accumulating.

BRIEF SUMMARY OF THE INVENTION

[0008] In one aspect, this disclosure is related to compositions and methods for controlling iron sulfide scale in various applications, such as oil and golf course management applications.

[0009] In another aspect, this disclosure is related to a method for preventing the formation of iron sulfide in an affected environment by first preparing a polytartaric acid(PTTA) polymer composition and applying the PTTA polymer composition at a concentration of greater than 20ppm to the affected environment. The polymer composition can include at least one metal salt and, in some embodiments, can be applied at a concentration between about lOppm and 200ppm.

[0010] In another aspect, this disclosure is related to A method for inhibiting the formation of iron sulfide in an environment comprising by first preparing a carboxylated oligomer including a metal (M), one or more polymers (n) and one or more corresponding groups (R), wherein M is Ca²⁺, Mg²⁺, Na⁺, K⁺, or NH ⁺ ; n is 1 to 1000; and R is H or Ci-₄ alkyl. The carboxylate oligomer can be applied to an environment at concentration of greater than 20ppm to the environment. Some embodiments of the composition can be a 40% solution by weight a of polyoxirane-2,3- dicarboxylate salt with a specific gravity of approximately 1.2.

[0011] The invention now will be described more fully hereinafter with reference to the accompanying drawings, which are intended to be read in conjunction with both this summary, the detailed description and any preferred and/or particular embodiments specifically discussed or otherwise disclosed. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided by way of illustration only and so that this disclosure will be thorough, complete and will fully convey the full scope of the invention to those skilled in the art.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Fig. 1 is a graph illustrating a three-hour comparison of FeS scale buildup using a control versus a composition of the present disclosure.

[0013] Fig. 2 is a graph illustrating iron sulfide inhibition over time using a composition of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

[0014] The following detailed description includes references to the accompanying drawings, which forms a part of the detailed description. The drawings show, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments, which are also referred to herein as "examples," are described in enough detail to enable those skilled in the art to practice the invention. The embodiments may be combined, other embodiments may be utilized, or structural, and logical changes may be made without departing from the scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense.

[0015] Before the present invention of this disclosure is described in such detail, however, it is to be understood that this invention is not limited to particular variations set forth and may, of course, vary. Various changes may be made to the invention described and equivalents may be substituted without departing from the true spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation, material, composition of matter, process, process act(s) or step(s), to the objective(s), spirit, or scope of the present invention. All such modifications are intended to be within the scope of the disclosure made herein.

[0016] Unless otherwise indicated, the words and phrases presented in this document have their ordinary meanings to one of skill in the art. Such ordinary meanings can be obtained by reference to their use in the art and by reference to general and scientific dictionaries.

[0017] References in the specification to "one embodiment" indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0018] The following explanations of certain terms are meant to be illustrative rather than exhaustive. These terms have their ordinary meanings given by usage in the art and in addition include the following explanations.

[0019] As used herein, the term "and/or" refers to any one of the items, any combination of the items, or all of the items with which this term is associated. [0020] As used herein, the singular forms "a," "an," and "the" include plural reference unless the context clearly dictates otherwise.

[0021] As used herein, the terms "include," "for example," "such as," and the like are used illustratively and are not intended to limit the present invention.

[0022] As used herein, the terms "preferred" and "preferably" refer to embodiments of the invention that may afford certain benefits, under certain circumstances. However, other embodiments may also be preferred, under the same or other circumstances.

[0023] Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful and is not intended to exclude other embodiments from the scope of the invention.

[0024] It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element without departing from the teachings of the disclosure.

[0025] The present disclosure provides a composition and method for inhibiting and/or combating the build up of iron sulfide scale in various affected environments. The composition can by a polymer composition, such as a polytartaric acid composition that can optionally include on or more metal salts. According to some exemplary embodiments, the composition for preventing iron sulfide build up or scale can be a carboxylated oligomer structure shown below:

[0026] Where M can be Ca²⁺, Mg²⁺, Na⁺, K⁺, or NH₄ ⁺; n is between about 1 to about 1000; and R can be H or C_1-4 alkyl. In other exemplary embodiments, organic alkaline cation materials, including but not limited to ethanolamine and L-arginine, among others. The composition can be applied using any suitable means including applying the composition directly to an affected environment at least lOppm. This application can be topically administered or through an irrigation or water system. In some exemplary embodiments, the composition can be applied at a concentration of at least 20ppm. In some exemplary embodiments, the size of the polymer (n) can be between about 1 to about 50 or about 1 to about 3. An exemplary embodiment of a carboxylated oligomer of the present disclosure can be applied to an environment as a primary application have a concentration of between about lOppm to about 200ppm of the

carboxylated oligomer. In some exemplary embodiments, one or more secondary application can be applied to the environment at various concentrations up to about 20,000ppm.

[0027] In one exemplary embodiment, the present disclosure can be directed towards methods of controlling iron sulfide scale in oil applications. According to an exemplary embodiment, iron sulfide scale inhibition can be accomplished by use of a carboxylated oligomer structure:

[0028] Where M can be Ca²⁺, Mg²⁺, Na⁺, K⁺, NhV; n is 1 to 1000; and R is H or C_1-4 alkyl. One exemplary embodiment of the present disclosure is directed towards a method of controlling scale in an aqueous system wherein a polytartaric acid (PTTA) polymer can be added to the aqueous system. In some exemplary embodiments, the size of the polymer (n) can be between about 1 to about 50 or about 1 to about 3. Some applications of an exemplary embodiment of the oligomer composition can be added to the system at a concentration of about 20 ppm or greater. The addition of the oligomer composition of the present disclosure can minimize the scale build up of iron sulfide. When making applications to the oil pipes, the polymer can be applied in a variety of solvent systems, aqueous or otherwise, and be applied as a salt to increase the solubility of the polymer.

[0029] As previously discussed, given the usual presence of iron from either from the formation water or from the degradation of iron piping and hydrogen sulfide from either indigenous gas, or gas produced by sulfate-reducing bacteria, iron sulfide scale can form. The generic formation of iron sulfide scale is Fe²⁺ + S^2_ = FeS, but the iron sulfide can exist as a variety of forms including pyrrhotite (Fel-xS) (where x = 0-0.2) (typically Fe7Ss) (monoclinic crystal structure), troilite (FeS) (hexagonal crystal structure), mackinawite (Fe,Nil+xS) (where x = 0-0.11) (typically FegNiSs), pyrite (FeS2) (iron sulfide with a cubic crystal structure), and marcasite (FeS2) (iron sulfide with an orthorhombic crystal structure). In addition to the reduced iron sulfide species, there's also a ferrous/ferric sulfide species, greigite (Fe₃S ), which can be a mixture of Fe(ll) and Fe(lll) iron, and can be the sulfur equivalent of the iron oxide, magnetite (Fe₃0₄).

[0030] The form of iron sulfide matters as the solubility in mineral acids varies greatly, with iron sulfides containing a 1:1 molar ratio of iron to sulfide being the most soluble. During formation of iron sulfide, the ratio of iron to sulfide in the iron-sulfide scale depends on the temperature, pressure, pH, and hydrogen sulfide concentration (Nasr-EI-Din, H.A.) As the scale ages, iron sulfide tends to increase in sulfur, which creates a type of iron sulfide that is even more insoluble even in the presence of mineral acids. Due to the environment in modern oil drilling, where pressures and temperatures are increased, the solution pH often is not high enough, and iron and hydrogen sulfide are both pervasive (but often in varying ratios), iron sulfide scale readily occurs. Once the scale occurs, one must determine the type of scale in order to determine whether it can be removed by chemical means, or whether it must be removed by mechanical means— or a combination of the two.

[0031] Current attempts have been made by chelating the iron (Fe2+ or Fe3+) that is present to prevent the formation of iron sulfide using chelates such as EDTA, DTPA, EDDHA, IDS, EDDS, NTA, citric acid, and the like. The drawback for this approach, however, is that the chelates work on a 1:1 molar ratio (or 1:2 or 2:3 in the case of citric acid) where one mol of chelate is needed for one mol of iron (except in the case of citric acid). Given the level of iron present, it is costly (and likely cost prohibitive) to apply a level of chelates sufficient to chelate all of the iron present. In addition to chelating iron, there are also methods currently used to try to scavenge the hydrogen sulfide gas by using hydrogen sulfide scavengers such as acrolein, zinc oxide, specific aldehydes, ketones, and oximes.

[0032] Many times, the effectiveness of these scavengers is dependent upon the pH of the drilling fluid and formation waters. In addition to chelates, and hydrogen sulfide scavengers, mechanical forces, and acid treatments (often with surfactants) are used to treat iron sulfide scale that has formed. Often chelates are used to chelate the iron once the mineral acid reverses the iron sulfide reaction, creating hydrogen sulfide gas and reduced (or theoretically oxidized) elemental iron. Hydrogen sulfide scavengers can also be used at this time. While these treatments work in part, the best and most cost-effective method to combat iron sulfide scale is to avoid its formation in the first place. In order to combat scale and reduce the costs associated with chelating using current modes, some exemplary embodiments of the present disclosure provide a composition including but not limited to a polytartaric acid (PTTA) composition and method of application as described herein.

[0033] In another exemplary embodiment, the present disclosure provides a method of controlling iron sulfide scale in soil, such as those found on a golf course. According to one exemplary embodiment, the iron sulfide scale inhibition can be accomplished using the application of a carboxylated oligomer structure shown below:

[0034] Where M can be Ca²⁺, Mg²⁺, Na⁺, K⁺, NH4⁺; n is between about 1 to about 1000; and R can be H or C1-4 alkyl. In other exemplary embodiments, organic alkaline cation materials, including but not limited to ethanolamine and L-arginine, among others. In some exemplary embodiments, the n can be about 1 to about 5 or about 1.2 to about 3, where n represents the size of the polymer of the composition. Additionally, the present disclosure provides a method of controlling scale in the soil wherein a polytartaric acid (PTTA) polymer composition can be added to the soil using any suitable method. In some exemplary embodiments, the

composition can be applied using a sprayer or through an irrigation system. The oligomer composition of the present disclosure can be added to the soil at a concentration of about 20 ppm or greater or between about 20ppm and about 200ppm, or about lOOppm in some exemplary embodiments. Similarly, some exemplary embodiments of the oligomer composition of the present disclosure can be applied at a concentration between about lOppm to about 200ppm or at about 20ppm to about lOOppm.

[0035] In an exemplary application of the oligomer composition of the present disclosure for a golf course, a polytartaric acid (PTTA) polymer composition of the present disclosure can be added to the surface with the irrigation water as a water-soluble salt (sodium, potassium, ammonium, calcium, magnesium, etc.). In another aspect, the product water containing the polymer composition of the present disclosure can be drenched into the soil with spraying equipment or injected into the soil with injection equipment. In yet another aspect, the polymer composition can be introduced during the aerification of the turf. In one exemplary embodiment, the oligomer composition of the present disclosure can include a primary treatment application that can include an injection of the polymer in a concentration of about 20 ppm or greater with each irrigation application. Secondary treatment applications of the oligomer composition can then be applied with successive applications of higher

concentrations. In some exemplary embodiments, the secondary treatments can be applied at up to 20,000 ppm throughout the season during aerification events and applications of wetting agents as an example. The secondary applications can be applied using a topical spray application on the desired area. The secondary treatments may also be applied at a

concentration of between about 10,000 and about 30,000 ppm. [0036] During golf course maintenance, iron may be applied regularly via liquid and granular applications in the form of many different types of iron minerals and chelated iron— both in the reduced and oxidized form of iron. Iron that isn't taken up by the plants immediately either precipitates in the soil (in the form of insoluble iron minerals) near the roots, where the roots can later release a phytosiderophore (such as mugineic acid) to chelate the iron, bring it into solution, and into the plant, or leaches farther down into the soil profile further away from the roots, where it is deposited as an insoluble mineral. As stated before, it is here where sulfate- reducing bacteria, create hydrogen sulfide gas from sulfates through their metabolic processes. The production of hydrogen sulfide gas creates insoluble iron sulfide deposits in the soil.

[0037] Iron sulfide can exist as a variety of forms including pyrrhotite (Fel-xS) (where x = 0- 0.2) (typically Fe7S8) (monoclinic crystal structure), troilite (FeS) (hexagonal crystal structure), mackinawite (Fe,Nil+xS) (where x = 0-0.11) (typically Fe9NiS8), pyrite (FeS2) (iron sulfide with a cubic crystal structure), and marcasite (FeS2) (iron sulfide with an orthorhombic crystal structure). In addition to the reduced iron sulfide species, there's also a ferrous/ferric sulfide species, greigite (Fe3S4), which is a mixture of Fe(ll) and Fe(lll) iron, and is the sulfur equivalent of the iron oxide, magnetite (Fe304). The accumulation of iron sulfide creates a layer in the soil known as "black layer." This "black layer" of soil, rich in iron sulfide deposits, is known for being anaerobic, and lacks the ability to effectively allow water to drain through the profile. This creates a layer where roots cannot grow, and water cannot penetrate which eventually jeopardizes the health of the entire stand of turf.

[0038] The continuous application of iron to the turf continues to feed the build up of iron sulfide, and thereby continues to grow the area of anaerobic conditions, and water penetration and percolation issues. In order to potentially combat and/or avoid the build up of iron sulfide, a preventative continuous applications of a composition of the present disclosure, such as polyoxirane-2,3-dicarboxylate salt, through the an irrigation system can be applied to the an affected environment. Many golf courses and other lawn care businesses can use existing equipment to inject sulfuric acid (which also contributes to the iron sulfide issues) to reduce the pH of the water. A similar injection method could be made with the polymer of the present disclosure. This is method is especially important for new golf courses as the use of the polymer is prohibitive, but not curative. As such, continuous applications of the polymer could prevent or forestall black layer issues from arising on golf courses.

EXAMPLES

[0039] The invention will now be described by way of examples; however, the invention is not necessarily limited by the examples.

Example #1

[0040] An initial application of an exemplary embodiment of the composition of the present disclosure which can be an about 40% solution (by weight) of sodium salt polyoxirane-2,3- carboxylic acid with a specific gravity of approximately 1.2 (10.0 lbs. per gallon) can be injected directly into an irrigation system on a golf course at approximately 100 ppm continuously with each irrigation application. Additionally, applications can then be applied at a pre-determined frequency. In some exemplary embodiments the applications can occur about every 30 days.

An additional secondary application of the polymer composition can be applied at about 20,000 ppm as a spray, and then irrigated into the profile of the treatment area. With the primary continuous injection application, along with the secondary applications, the levels of polyoxirane-2,3-carboxylic acid can be maintained consistently throughout the profile of the soil. These applications can directly decrease the iron sulfide production in the soil profile, creating a more hospitability habitat for root growth and soil percolation. The additional secondary applications can be spread over the environment using any suitable methods, such as a traditional mist sprayer used in the turf industry. In some embodiments, the composition applied to the environment can be between about 20% to about 60% solution by weight of polyoxirane-2,3-carboxylate salt.

Example #2

[0041] Stock solutions can first be continuously purged with high purity Nitrogen gas for at least 2 hours to remove any dissolved oxygen and filtered through an about 0.22 pm filter.

Once the solutions are oxygen free, they can be placed through a Dynamic Scale Loop with continuous Nitrogen purging throughout the run. The cation and anion solutions can each be pumped through an HPLC pump at the rate of about 5 ml/min. The oven can be set at 86°C with a back pressure of about 1500 psi. When the cation and anion meet inside the mixing coil, scale deposits can form, creating differential pressure across the coil. Higher inhibitor efficiency can result in lower differential pressure. As shown in Fig. 1, after about three hours the control differential pressure was about 16 times higher than the treatment with about 100 ppm polytartaric acid (PTTA). In some exemplary embodiments, piperazine-N, N'bis (2- ethanesulfonic acid) can be used as a buffer to imitate the pH conditions encountered in an affected environment. Similarly, the tables below and Fig. 2 illustrate the inhibition of iron sulfide over a period of time at one environmental condition.

Table 1

Table 2

[0042] While the invention has been described above in terms of specific embodiments, it is to be understood that the invention is not limited to these disclosed embodiments. Upon reading the teachings of this disclosure many modifications and other embodiments of the invention will come to mind of those skilled in the art to which this invention pertains, and which are intended to be and are covered by both this disclosure and the appended claims. It is indeed intended that the scope of the invention should be determined by proper interpretation and construction of the appended claims and their legal equivalents, as understood by those of skill in the art relying upon the disclosure in this specification and the attached drawings.

Claims

CLAIMS What is claimed is:

1. A polymer composition for inhibiting the formation of iron sulfide comprising:

an oligomer corresponding to the formula: wherein M can be Ca²⁺, Mg²⁺, Na⁺, K⁺, or NhV; n is 1 to 1000; and R is H or C_1-4 alkyl.

2. The composition of claim 1, wherein the composition is a polytartaric acid (PTTA) polymer composition.

3. The composition of claim 2, wherein the n is between 1 and 3.

4. The composition of claim 2, further comprising a buffer of acetic acid wherein the composition has a pH between 6 and 8.

5. The composition of claim 1, wherein the composition is a 40% solution by weight of a sodium salt of polyoxirane-2,3-carboxylic acid with a specific gravity of approximately 1.2 and a pH between 6 and 8.

6. The composition of claim 5, wherein in n is between 1 and 3.

7. A method for preventing the formation of iron sulfide in an environment comprising: preparing a polytartaric acid (PTTA) polymer composition; and applying the PTTA polymer composition at a concentration of greater than 20ppm to the environment.

8. The method of claim 7, wherein the PTTA polymer composition includes at least one metal salt.

9. The method of claim 8, wherein the metal salt includes at least on of the following:

Ca²⁺, Mg²⁺, Na⁺, K⁺, NH₄ ⁺

10. The method of claim 9, where in the polymer composition is applied as a primary application at a concentration between about lOppm to about 200ppm.

11. The method of claim 10, wherein the primary application is applied through an injection of the PTTA polymer composition to an irrigation system treating the environment.

12. The method of claim 10, wherein the primary application is applied through injection of the PTTA polymer composition into the environment.

13. The method of claim 10, wherein the polymer composition is applied as a secondary application at a concentration greater than that of the primary application.

14. The method of claim 13, wherein the concentration of the secondary application is between about 10,000 and about 30,000 ppm.

15. The method of claim 13, wherein the concentration of the secondary application is less than 20,000ppm.

16. The method of claim 15, wherein the secondary application is applied to the

environment at least every 30 days.

17. The method of claim of claim 10, wherein the polymer size is between 1 and 3.

18. The method of claim 10, wherein the primary application is a 40% solution by weight a of polyoxirane-2,3-dicarboxylate salt with a specific gravity of approximately 1.2.

19. A method for inhibiting the formation of iron sulfide in an environment comprising: preparing a polymer composition corresponding to the formula:

wherein M is Ca²⁺, Mg²⁺, Na⁺, K⁺, or NhV; n is 1 to 1000; and R is H or C_1-4 alkyl.; and applying the polymer composition at a concentration of greater than 20ppm to the environment.

20. The method of claim 19, wherein the polymer composition is a 40% solution by weight of polyoxirane-2,3-dicarboxylate sale with a specific gravity of approximately 1.2.