WO2025080251A1

WO2025080251A1 - Separation-promoting agents for oil & water treatments in desalter processes

Info

Publication number: WO2025080251A1
Application number: PCT/US2023/035143
Authority: WO
Inventors: Leonardo FRANCA; Joseph Arensdorf; Chad Pyle; Radhika SURESH; Dolog ROSTYSLAV
Original assignee: Baker Hughes Oilfield Operations LLC
Current assignee: Baker Hughes Oilfield Operations LLC
Priority date: 2023-10-13
Filing date: 2023-10-13
Publication date: 2025-04-17
Anticipated expiration: 2026-04-13

Abstract

In one aspect, a demulsification additive includes a separation-promoting agent and a solvent. In another aspect, a demulsification additive includes a separation-promoting agent and a demulsifier or demulsifier intermediate. In another aspect, a method for separating crude oil from water includes introducing the water to the cmde oil, providing a demulsification additive that includes a separation-promoting agent, and contacting the water and the crude oil with the demulsification additive. In one embodiment, the separation-promoting agent is selected from the group consisting of dextran sulfate sodium salt, polyvinyl pyrrolidone functionalized with sodium salt of chloroacetic acid, poly(ethyleneglycol)-b(propyleneglycol)-b(ethyleneglycol) block copolymer, polyvinyl pyrrolidone functionalized with propyl sulfonate, sulfonated polyether ether ketone polymer, polyvinyl pyrrolidone functionalized with bromohexane, polyvinyl pyrrolidone functionalized with iodododecane, and combinations thereof.

Description

SEPARATION-PROMOTING AGENTS FOR OIL & WATER TREATMENTS IN DESALTER PROCESSES

FIELD OF THE INVENTION

[001] This invention generally relates to the separation of contaminants from fluids and, more particularly, but not by way of limitation, to a formulation and method for promoting the separation of water and other contaminants from oil in desalter processes.

BACKGROUND OF THE INVENTION

[002] Crude oil is often contaminated with water, inorganic salts, suspended solids, and trace metals. To reduce corrosion, plugging, and fouling of equipment and to prevent poisoning the catalysts in processing units, refineries must remove these contaminants, in particular water and associated salts, by a desalting process.

[003] To remove unwanted contaminants, crude oil is initially mixed with fresh water

(or “wash water”) to form an emulsion, causing contaminants from the crude oil to partition into the emulsion or water phase. Demulsifiers are also injected to break the emulsion into oil and water phases before the blend of crude oil and wash water flows into a desalter. These demulsifiers encourage flocculation of oil droplets and coalescence of water droplets, such that oil-water separation occurs within a time frame that satisfies refinery throughput constraints. Current demulsifier intermediates are often large organic molecules that are resin- or surfactant-based. Demulsifiers are also expensive and are developed specifically to treat one kind of oil.

[004] Once the oil-water-demulsifier blend flows into the desalter, charged electrical grids further promote water droplet coalescence and cause the water to migrate downward in the desalter vessel. The resulting dry and purified desalted crude is then pulled out of the top of the desalter and sent to distillation towers, while the water (now laden with contaminants) exits from the desalter’s bottom as a brine and is sent to a wastewater treatment plant (WWTP) to be purified. [005] Despite these established separation techniques, brine from the desalter is often contaminated with residual oil that is difficult to process at the WWTP. One method of avoiding brine contamination is to use water clarifiers to increase the speed and efficiency of oil-water separation in the water phase of the desalter. Water clarifiers often include polymer brine dispersants and dimethyldithiocarbamate products, which can be expensive and highly toxic. These water clarifiers may also create negative side effects within the desalter, such as an uncontrolled interface layer.

[006] Contamination of the brine with oil is worsened by the presence of debris at the bottom of the desalter, such as heavy organic solids, production sand and heavy tars mixed with inorganic salts. The debris tends to stabilize the presence of oil in water. To remediate this issue, the desalter may be chemically cleaned with polymers of high molecular weight to remove the solids. Although generally effective, these chemical debris cleaners are often introduced in quantities that create over-dosage and may cause oil-water interface issues in the desalter.

[007] Although widely adopted, current demulsifiers, water clarifiers, and chemical debris cleaners pose notable challenges for efficacy, cost, and the mitigation of adverse environmental impact. A need exists, therefore, for chemistries that addresses the current deficiencies of oil-water separation in desalters. The present disclosure is directed at these and other deficiencies in the prior art.

SUMMARY OF THE INVENTION

[008] In one embodiment, a demulsification additive includes a separation-promoting agent and a solvent. The separation-promoting agent is an oxide nanoparticle, a carbon-based nanoparticle, a nitride, a polymer, or a mixture of nanoparticles and/or polymers.

[009] In another embodiment, the demulsification additive includes a separationpromoting agent and a demulsifier or demulsifier intermediate. [0010] In yet another embodiment, a method for separating crude oil from water includes introducing the water to the crude oil, providing a separation-promoting agent, and contacting the water and the crude oil with the separation-promoting agent.

DETAILED DESCRIPTION

[0011] It has been discovered that a demulsification additive can be used to facilitate separation of oil from water at various points of a desalter. In one embodiment, the demulsification additive includes a separation-promoting agent. In various non-limiting embodiments, the separation-promoting agent is an oxide nanoparticle, a carbon-based nanoparticle, a nitride, or a polymer. In other embodiments, the separation-promoting agent is a mixture of nanoparticles and/or polymers.

[0012] Several separation-promoting agents with a size of less than 100 nanometers (nm) may be used to speed up water separation processes in a desalter, as well as improve the quality of the processed oil, interface, and brine. These separation-promoting agents demonstrate dual action as coagulants and flocculants for organic and inorganic particles dissolved in water. These separation-promoting agents are more efficient than typical demulsifiers, water clarifiers, and desalter debris cleaners. These separation-promoting agents separate oil and water at reduced dosage and cost compared to traditional products. Further, the separation-promoting agents prevent adverse interface issues and reverse emulsion formation caused by traditional desalter chemistries. The separation-promoting agents provide the additional benefit of purifying water without chlorination.

[0013] In embodiments where the separation-promoting agent includes one or more oxide nanoparticles, the nanoparticle(s) may include iron oxide, zinc oxide, and magnesium oxide. Suitable carbon-based nanoparticles for the separation-promoting agent include oxidized carbon, graphene oxide, fluorinated nanodiamond, NH2 functionalized graphene, titanium oxide-graphene, and oxidized sucrose. These nanoparticles have one or more properties that influence their ability to separate fluids and make them better candidates for the separation-promoting agent than larger particles. These properties include size- and shapedependent properties, a high surface area to mass ratio, the presence of surface charge and polarity (the charge density⁷ of the media), the ability to penetrate an oil-water interface, and the ability to adsorb asphaltenes, resins, and other natural emulsifying agents based on the presence of surface functionalization groups.

[0014] In embodiments where the separation-promoting agent includes nitrides, both titanium nitride cubic and aluminum nitride are suitable.

[0015] Suitable polymers for use as the separation-promoting agent include dextran sulfate sodium salt, polyvinyl pyrrolidone functionalized with sodium salt of chloroacetic acid, poly(ethyleneglycol)-b(propyleneglycol)-b(ethyleneglycol) block copolymer, sulfonated poly ether ether ketone (PEEK) polymer, and polyvinyl pyrrolidone functionalized with propyl sulfonate, bromohexane, or iodododecane.

[0016] In some instances, it may be desirable for the demulsification additive to influence the turbidity of the water upon separation from the oil. The following separationpromoting agents are useful for decreasing turbidity: polyvinyl pyrrolidone functionalized with sodium salt of chloroacetic acid, cubic titanium nitride, oxidized sucrose, zinc oxide, iron oxide, and aluminum nitride. Other separation-promoting agents — including fluorinated nanodiamond, oxidized carbon, graphene oxide, titanium dioxide-graphene, and sulfonated PEEK polymer — are useful for decreasing turbidity.

[0017] In one embodiment, the demulsification additive further includes a solvent. The solvents used for diluting the separation-promoting agent are typically water or cheap solvents. Many of the above separation-promoting agents are water soluble and can therefore formulate products with water as a carrier solvent. It will be appreciated that organic solvents — such as those used to make dilutions for the demulsifier intermediates toluene, U14, and xylene — may also be used. In various embodiments, the solvent component of the demulsification additive may include water, ethanol, isopropanol, hexane, or combinations of the same. The following table presents a non-limiting list of example pairings for the separation-promoting agent and the solvent:

[0018] In one embodiment, the weight (wt.) % of the separation- promoting agent in the demulsification additive is between about 20 wt.% to about 90 wt.%. In other embodiments, the concentration of separation-promoting agent is between about 20 wt.% to about 50 wt.%. The concentration of separation-promoting agent in some embodiments is approximately 50 wt.%.

[0019] In one embodiment, the separation-promoting agent is blended with a traditional demulsifier to offer the same or better performance at low er doses. In some embodiments, the demulsification additive includes one or more demulsifiers or demulsifier intermediates, including but not limited to acid catalyzed phenol-formaldehyde resins, base catalyzed phenolformaldehyde resins, dendrimers, di-epoxides, epoxy resins, polyethyleneimines, polyamines, polyols. The concentration of the demulsifier or demulsifier intermediate in the additive maybe between about 50 wt.% to about 90 wt.%.

[0020] In another embodiment, a method for separating crude oil from water involves introducing the water to the crude oil, providing a demulsification additive that includes a separation-promoting agent, and contacting the water and the crude oil with the demulsification additive. The demulsification additive may be contacted with the water and the crude oil in various ways. In one embodiment, the demulsification additive is introduced into the water and the crude oil before they are directed together into a desalter. The demulsification additive may therefore either replace or complement a traditional demulsifier in the desalting process. In another embodiment, the demulsification additive is injected into the bottom of the desalter and may replace traditional debris cleaners to remove desalter debris that promotes water contamination with oil. In yet another embodiment, the demulsification additive can be injected into a brine exiting the desalter. In this instance, the demulsification additive assists in the removal of residual oil from the brine and may serve as a water clarifier.

[0021] It will be appreciated that the step of providing the demulsification additive may further include the step of mixing the separation-promoting agent with a solvent. The step of providing the demulsification additive may also optionally include the step of mixing the separation-promoting agent with a demulsifier or demulsifier intermediate.

[0022] Although discussion of the separation-promoting agent has thus far focused on use with a desalter, it will be appreciated that this technology may also be scaled up for use at urban wastewater treatment plants and other facilities within oil and gas plants. EXAMPLE I

[0023] A round of tests was performed to screen for nanoparticles and polymers as candidates for the separation-promoting agent. For these tests, prescription bottles were initially filled with 100 mL of brine collected from the field, with an addition 5 mL of crude oil then added to each bottle. All bottles were submitted to a bottle shaker for five (5) minutes. A low dosage of 15 ppm for each tested nanoparticle and polymer was then added to each of the bottles except for the blank, and all bottles were then agitated by hand approximately one hundred (100) times before visual inspection. Each bottle was photographed for visual analysis within five (5) minutes of this agitation-by-hand. After thirty (30) minutes, the bottles containing nanoparticles/polymers demonstrated little to no residual oil, while the blank demonstrated more residual oil and solid contaminants, as well as a longer time to flocculate. Some nanoparticles/polymers showed no oil at the top of the bottle but cloudy water, suggesting a good tendency to drop solids into the water phase while also reducing oil-in-water content.

[0024] After thirty (30) minutes since agitation, 3 mL of sample was collected from each bottle at the 50 mL mark at room temperature, and these 3 mL samples were tested for oil and water quality with a turbidimeter. The results were as follows:

[0025] The “Oil (Top)” measurement is the observation of oil in the top of the bottle and is graded according to the following scale: 0 = no oil shown: 4 = high amount of oil shown. A larger Oil (Top) score indicates slower oil flocculation with less oil-water separation. The “Turb/NTU” score refers to a turbidity assessment using the Nephelometric Turbidity Unit (NTU) standard, where a lower score indicates the presence of fewer solid particles in the liquid. It is acknowledged that the turbidity measurements, shown above in nephelometric turbidity units (“NTU”), may be influenced by reducing or raising the dosage of the separationpromoting agent from 15 ppm. The “Efficiency” score provides a comparative analysis of the overall effectiveness of the various separation-promoting agents at the 15 ppm test dosage.

EXAMPLE II

[0026] Additional rounds of testing were performed to screen separation-promoting agent candidates to identify those that facilitate swift breaking of emulsions for the separation of oil and water and provide good oil dehydration. The observed parameters included oil quality, interface quality, speed of water separation, and level of dehydration.

[0027] For this testing, a crude oil sample w as obtained from different field locations. This crude oil-wash water mixture w as introduced into individual sample tubes, and the tubes were briefly subjected to a blender. Each evaluated separation-promoting agent was then injected into each of the sample tubes, which were placed into an Electrical Desalting Dehydration Apparatus (EDDA) for thirty (30) minutes, with a water drop measurement taken every' five (5) minutes. The EDDA instrument models a desalter by applying an electrical field to the oil-w ater sample tubes inserted into a cell. EDDA measurements were taken under the following parameters: 50% variac, 120°C, and 1500 V. [0028] A total of fi fty-nine (59) separation-promoting agent candidates were screened, with water drop measurements obtained at 0, 5, 10, 15, 20, 25 and 30 minutes. The following candidates (and corresponding solvents) were identified as promoting good separation in the water drop, defined as having water separation with more than 45% efficiency:

EXAMPLE III

[0029] Additional ratio tests were conducted using dosages of 10, 16, 20 and 30 ppm.

The following separation-promoting agents showed similar results at all dosages submitted:

EXAMPLE IV

[0030] For this round of testing, the top-performing separation-promoting agents from Examples II-III were mixed with an acid catalyzed resin demulsifier intermediate. Good improvement was observed for water drop speed, interface quality, and water quality when the separation-promoting agents were combined with just 5 ppm of intermediate. Minor improvement was observed for oil quality.

[0031] In the foregoing specification, the invention has been described with reference to specific embodiments thereof. However, it will be evident that various modifications and changes can be made thereto without departing from the broader scope of the invention as set forth in the appended claims. Accordingly, the specification is to be regarded in an illustrative rather than a restrictive sense. The present invention may suitably comprise, consist of, or consist essentially of the elements disclosed and may be practiced in the absence of an element not disclosed. As used herein, the singular forms '‘a,” “an,’’ and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. As used herein, the term “about” in reference to a given parameter is inclusive of the stated value and has the meaning dictated by the context (e.g., it includes the degree of error associated with measurement of the given parameter). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

Claims

It is claimed:

1. A demulsification additive comprising: about 20 wt.% to about 90 wt.% of a separation-promoting agent, wherein the separation-promoting agent is selected from the group consisting of dextran sulfate sodium salt, polyvinyl pyrrolidone functionalized with sodium salt of chloroacetic acid, poly(ethyleneglycol)-b(propyleneglycol)-b(ethyleneglycol) block copolymer, polyvinyl pyrrolidone functionalized with propyl sulfonate, sulfonated polyether ether ketone polymer, polyvinyl pyrrolidone functionalized with bromohexane, polyvinyl pyrrolidone functionalized with iodododecane, and combinations thereof and a solvent.

2. The demulsification additive of claim 1. wherein the solvent is selected from the group consisting of water, ethanol, isopropanol, hexane, and combinations thereof.

3. The demulsification additive of claim 1, wherein the concentration of the separation-promoting agent in the demulsification additive is between about 20 wt.% to about 50 wt.%.

4. The demulsification additive of claim 1. wherein the concentration of the separation-promoting agent in the demulsification additive is approximately 50 wt.%.

5. The demulsification additive of claim 1 further comprising: a demulsifier or demulsifier intermediate selected from the group consisting of acid catalyzed phenol-formaldehyde resins, base catalyzed phenol-formaldehyde resins, dendrimers, di-epoxides, epoxy resins, polyethyleneimines, polyamines, polyols, and combinations thereof.

6. The demulsification additive of claim 5, wherein the concentration of the demulsifier or demulsifier intermediate in the demulsification additive is between about 50 wt.% to about 90 wt.%.

7. A demulsification additive comprising: a separation-promoting agent selected from the group consisting of dextran sulfate sodium salt, polyvinyl pyrrolidone functionalized with sodium salt of chloroacetic acid, poly(ethyleneglycol)-b(propyleneglycol)-b(ethyleneglycol) block copolymer, polyvinyl pyrrolidone functionalized with propyl sulfonate, sulfonated polyether ether ketone polymer, polyvinyl pyrrolidone functionalized with bromohexane, polyvinyl pyrrolidone functionalized with iodododecane, and combinations thereof; and a demulsifier or demulsifier intermediate, wherein the concentration of the demulsifier or demulsifier intermediate in the demulsification additive is between about 50 wt.% to about 90 wt.%.

8. The demulsification additive of claim 7, wherein the concentration of the separation-promoting agent in the demulsification additive is between about 20 wt.% to about 90 wt.%.

9. The demulsification additive of claim 7, wherein the demulsifier or demulsifier intermediate is selected from the group consisting of acid catalyzed phenol-formaldehyde resins, base catalyzed phenol-formaldehyde resins, dendrimers, di-epoxides, epoxy resins, polyethyleneimines, polyamines, polyols, and combinations thereof.

10. The demulsification additive of claim 7 further comprising a solvent.

11. The demulsification additive of claim 10, wherein the solvent is selected from the group consisting of water, ethanol, isopropanol, hexane, and combinations thereof.

12. A method for separating crude oil from water comprising: introducing the water to the crude oil; providing a demulsification additive, wherein the demulsification additive comprises about 20 wt.% to about 90 wt.% of a separation-promoting agent selected from the group consisting of dextran sulfate sodium salt, polyvinyl pyrrolidone functionalized with sodium salt of chloroacetic acid, poly(ethyleneglycol)- b(propyleneglycol)-b(ethyleneglycol) block copolymer, polyvinyl pyrrolidone functionalized with propyl sulfonate, sulfonated polyether ether ketone polymer, polyvinyl pyrrolidone functionalized with bromohexane, polyvinyl pyrrolidone functionalized with iodododecane, and combinations thereof; and contacting the water and the crude oil with the demulsification additive.

13. The method of claim 12, wherein the step of providing the demulsification additive further comprises the step of mixing the separation-promoting agent with a solvent.

14. The method of claim 13, wherein the step of mixing the separation-promoting agent with the solvent further comprises the step of selecting the solvent from the group consisting of water, ethanol, isopropanol, hexane, and combinations thereof.

15. The method of claim 12, wherein the step of providing the demulsification additive further comprises the step of mixing the separation-promoting agent with a demulsifier or demulsifier intermediate

16. The method of claim 15, wherein the step of mixing the separation-promoting agent with the demulsifier or demulsifier intermediate further comprises the step of selecting the demulsifier or demulsifier intermediate from the group consisting of acid catalyzed phenol-formaldehyde resins, base catalyzed phenol-formaldehyde resins, dendrimers, diepoxides, epoxy resins, polyethyleneimines, polyamines, polyols, and combinations thereof.

17. The method of claim 15, wherein the step of mixing the separation-promoting agent with the demulsifier or demulsifier intermediate further comprises the step of adding the demulsifier or demulsifier intermediate to obtain a concentration of between about 50 wt.% to about 90 wt.% in the demulsification additive.

18. The method of claim 12 further comprising the step of directing the water, the crude oil. and the demulsification additive into a desalter.

19. The method of claim 12, wherein the step of contacting the water and the crude oil with the demulsification additive further comprises the step of injecting the demulsification additive into the bottom of a desalter.

20. The method of claim 12, wherein the step of contacting the water and the crude oil with the demulsification additive further comprises the step of injecting the demulsification additive into a brine exiting a desalter.