Method for at least partially separating a combination of oil and water

Abstract

A method for at least partially separating a combination of oil and water includes the steps of adding colloidal silica to the combination of oil and water and adding a separating agent to the combination of oil and water simultaneously with, prior to, and / or subsequent to adding the colloidal silica to the combination of oil and water, thereby effecting at least partial separation of the oil and the water. The separating agent comprises a cellulose ether having the following structure (I): (I) wherein each R1, R2 and R3 is independently H, a carboxymethyl group, a C1-C18 alkyl group, or a C2-C3 hydroxy alkyl group, so long as not all R1, R2 and R3 are H; and wherein n is from about 800 to about 10,000. A composition itself includes the colloidal silica and the separating agent. An emulsion itself includes oil, water, the colloidal silica, and the separating agent.

Description

PCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PCMETHOD FOR AT LEAST PARTIALLY SEPARATING A COMBINATION OF OIL AND WATERCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 762,918 filed on February 25, 2025, which is hereby expressly incorporated herein by reference in its entirety. This application also claims the benefit of U.S. Provisional Application No. 63 / 925,951 filed on November 26, 2025, which is hereby expressly incorporated herein by reference in its entirety.TECHNICAL FIELD

[0002] The present disclosure generally relates to a method for at least partially separating a combination of oil and water. More specifically, this disclosure relates to a method that utilizes colloidal silica and a particular cellulose ether separating agent that provide unexpected synergy and separation efficiency.BACKGROUND

[0003] In oilfield operations, the separation of oil and water impacts production efficiency, environmental compliance, and operational costs. Crude oil extracted from reservoirs often contains significant amounts of water, which must be effectively separated before the oil can be refined or transported. The presence of water in crude oil can lead to equipment corrosion, reduced product quality, and increased processing costs. Additionally, water produced during oil extraction, known as produced water, must be treated before being discharged or reinjected into the reservoir, requiring efficient separation techniques.

[0004] Traditional oil-water separation techniques rely on gravity separation, chemical demulsifiers, and mechanical devices such as hydrocyclones and coalescers. Gravity separation, while effective for large density differences between oil and water, is slow and requires large settling tanks, which are often impractical in offshore and space-constrained environments. Chemical demulsifiers, which break emulsions and enhance phase separation, introduce additional costs and potential environmental concerns. Mechanical separation methods such as hydrocyclones and centrifuges provide faster separation but are energy-intensive and less effective in handling stable emulsions with fine water droplets.

[0005] One of the most significant challenges in oil-water separation is the presence of stable emulsions, which occur when fine water droplets are dispersed within an oil phase due to naturalPCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PCsurfactants, shear forces, and chemical additives used in production. These emulsions resist conventional separation techniques and require additional processing steps, increasing operational complexity and cost. Furthermore, stringent environmental regulations impose strict limits on the amount of oil that can be present in discharged water, necessitating highly efficient separation methods.

[0006] Given these challenges, there is a need for improved oil-water separation technologies that enhance efficiency, reduce operational costs, and minimize environmental impact. The present disclosure addresses these longstanding issues by introducing a novel approach to oil-water separation that overcomes the limitations of traditional methods. Furthermore, other desirable features and characteristics of the present disclosure will become apparent from the subsequent detailed description of the disclosure and the appended claims, taken in conjunction with the accompanying drawings and this background of the disclosure.BRIEF SUMMARY

[0007] This disclosure provides a method for at least partially separating a combination of oil and water. The method includes the steps of adding colloidal silica to the combination of oil and water and adding a separating agent to the combination of oil and water simultaneously with, prior to, and / or subsequent to adding the colloidal silica to the combination of oil and water, thereby effecting at least partial separation of the oil and the water. The separating agent comprises a cellulose ether having the following structure (I):wherein each R1, R2and R3is independently H, a carboxymethyl group, a Cl -Cl 8 alkyl group, or a C2-C3 hydroxy alkyl group, so long as not all R1, R2and R3are H; and wherein n is from about 800 to about 10,000.PCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PC

[0008] This disclosure also provides a composition that includes the colloidal silica and the separating agent. This disclosure further provides an emulsion that includes oil, water, the colloidal silica, and the separating agent.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The present disclosure will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and

[0010] FIG. 1A is a bar graph setting forth the results of the Examples relative to clarity rating as a function of time at a 5ppm dose rate;

[0011] FIG. IB is a photograph of the results of the Examples corresponding to FIG. 1A;

[0012] FIG. 2A is a bar graph setting forth the results of the Examples relative to clarity rating as a function of time at a lOppm dose rate;

[0013] FIG. 2B is a photograph of the results of the Examples corresponding to FIG. 2A;

[0014] FIG. 3 is a photograph of the results of the evaluation of various colloidal silicas (Colloidal Silica 2 and Colloidal Silica 3) at a lOppm dose rate with the use of the same particular separating agent; and

[0015] FIG. 4 is a photograph of the results of the evaluation of particular colloidal silicas at a lOppm dose rate without the use of a separating agent.DETAILED DESCRIPTION

[0016] The following detailed description is merely exemplary in nature and is not intended to limit the current composition. Furthermore, there is no intention to be bound by any theory presented in the preceding background or the following detailed description.

[0017] Embodiments of the present disclosure are generally directed to colloidal silica, polymers, compositions including the same, and methods for forming and using the same. For the sake of brevity, conventional techniques related to making colloidal silica and polymers and such compositions may not be described in detail herein. Moreover, the various tasks and process steps described herein may be incorporated into a more comprehensive procedure or process having additional steps or functionality not described in detail herein. In particular, various steps in the manufacture of polymers and associated compositions are well-known and so, in the interest of brevity, many conventional steps will only be described briefly herein or will be omitted entirely without providing the well-known process details.PCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PC

[0018] In this disclosure, the terminology “about” can describe values ± 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10%, in various embodiments. Moreover, it is contemplated that, in various non-limiting embodiments, it is to be appreciated that all numerical values as provided herein, save for the actual examples, are approximate values with endpoints or particular values intended to be read as “about” or “approximately” the value as recited. It is also contemplated that all isomers and chiral options for each compound described herein are hereby expressly contemplated for use herein in various non-limiting embodiments.

[0019] Throughout this disclosure, the terminology percent "actives" is well recognized in the art and means the percent amount of active or actual compound or molecule present as compared to, for example, a total weight of a diluted solution of a solvent and such a compound. Some compounds, such as a solvent, are not described relative to a percent actives because it is well known to be approximately 100% actives. Any one or more of the values described herein may be alternatively described as percent actives as would be understood by the skilled person.

[0020] In various embodiments, the terminology “free of’ describes embodiments that include less than about 5, 4, 3, 2, 1, 0.5, or 0.1, weight percent (or weight percent actives) of the compound or element at issue using an appropriate weight basis as would be understood by one of skill in the art. In other embodiments, the terminology “free of’ describes embodiments that have zero weight percent of the compound or element at issue.

[0021] The terminology “consists essentially of’ may describe various non-limiting embodiments that are free of one or more optional compounds described herein and / or free of one or more polymers, surfactants, additives, solvents, etc.

[0022] It is to be understood that the subscripts of polymers are typically described as average values because the synthesis of polymers typically produces a distribution of various individual molecules.

[0023] The compounds and compositions disclosed herein may typically comprise, consist of, or consist essentially of the components, elements, and process delineations described herein. The embodiments illustratively disclosed herein typically may be practiced in the absence of any element which is not specifically disclosed herein. Moreover, every external reference mentioned herein is expressly incorporated herein by reference in its entirety in various non-limiting embodiments.PCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PCMethod of the Disclosure

[0024] This disclosure provides a method for at least partially separating a combination of oil and water. The combination may alternatively be described as an oilfield composition. The method includes the steps of adding colloidal silica to the combination of oil and water and adding a separating agent to the combination of oil and water simultaneously with, prior to, and / or subsequent to adding the colloidal silica to the combination of oil and water, thereby effecting at least partial separation of the oil and the water.Combination of Oil and Water

[0025] The combination of oil and water may be any known in the art. This combination may be described as any water-based stream, the major constituent of which is either tap water, fresh water, a brine, salt water, seawater, or the like, either as a natural additive during a commercial manufacturing procedure, or in the fluids which are used to drill, complete or workover a subterranean oil or gas well, in production streams of fluid hydrocarbons from subterranean wells, and the like, regardless of whether the water is present intentionally, incidentally or accidentally. The oil may either be produced hydrocarbons, such as those which are found in a production well, or any hydrocarbon-, or grease-containing chemicals, sulfur, or similar constituent found in many typical manufacturing procedures, described above.

[0026] In various embodiments, the combination may be described as a partially biphasic system which can form when oil and water are mixed without external agents. Alternatively, the combination may be described as an emulsion, e.g. a macro- or micro-emulsion. The macroemulsion may be a coarse dispersion where one phase (dispersed phase) is entrained within the other (continuous phase) wherein in droplet sizes have a particle size from about 1 to about 100 microns. Such emulsions may be alternatively described as oil-in-water emulsions (O / W emulsions), water-in-oil emulsions (W / O emulsions), or Multiple or Complex Emulsions (W / O / W or O / W / O) wherein a primary emulsion (e.g., W / O or O / W) is further emulsified into another continuous phase. Even further, the combination may be described as a microemulsion which is a thermodynamically stable system formed by surfactant-mediated dispersion of one liquid in another, resulting in droplet sizes below about 100 nm. Alternatively, the combination may be described as a Pickering emulsion or as a colloidal suspension. Any type of combination known in the art may be utilized.PCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PC

[0027] In various embodiments, the combination is further defined as an O / W (oil in water) emulsion, which may be described as a dispersion of crude oil, e.g. as oil droplets, in water. Accordingly, the crude oil may be described as a dispersed phase and the water may be described as a continuous phase of the combination, e.g. the OAV emulsion. Any “oil” described herein may alternatively be described as crude oil for purposes of description.

[0028] The “crude oil” may also be described as “oil,” and may be from various sources, e.g. from a sedimentary basin, a sandstone or limestone reservoir, a continental shelf, a deepwater reservoir, a shale formation, etc. The crude oil may be refined or unrefined, paraffinic or naphthenic, and may include various types of hydrocarbons, e.g. alkanes, cycloalkanes, aromatic hydrocarbons, etc., and / or non-hydrocarbons including organic compounds that include sulfur, nitrogen, oxygen, and trace metals. Accordingly, the crude oil may exhibit various physical properties, e.g. viscosity, density, etc. and chemical properties, e.g. sulfur content, aromatic content, etc. For example, the crude oil may be free flowing or viscous at room temperature. Additionally, the crude oil may exhibit a density, which may be measured using any methods known in the art, e.g. according to standardized methods such as ASTM D4052, ISO 12154:2014, etc., by using an apparatus such as a hydrometer, a Coriolis density meter, or calculated from the weight and volume of the combination of oil and water, etc. In various embodiments, the density of the crude oil may be measured relative to the specific density of water, also known as API gravity, of about 10 to about 49 degrees, about 10 to about 20 degrees, about 20 to about 30 degrees, about 30 to about 40 degrees, about 10 to about 30 degrees, about 20 to about 40 degrees, about 15 to about 49, etc. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those set forth above are expressly contemplated for use herein. A larger API gravity describes a lighter density crude oil compared to a crude oil with a smaller API gravity.

[0029] The crude oil may also be described as “sweet” or “sour,” which is known in the art to describe a sulfur content of less than about 1 wt% or 1 wt% or more, based on a total weight of the crude oil, respectively. The sulfur content of the crude oil may be from about 0.1 to 2 wt%, about 0.1 to about 0.5 wt%, about 0.5 to about 1 wt%, about 0.5 to about 1 wt%, about 1 to about 1.5 wt%, about 1.5 to about 2 wt%, about 0.1 to about 1 wt%, about 1 to about 2 wt%, about 0.5 to about 1.5 wt%, etc. In various non-limiting embodiments, all values and ranges of values, bothPCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PCwhole and fractional, including and between those set forth above are expressly contemplated for use herein.

[0030] The crude oil may be present in various amounts, dependent on different oilfield process, methods of treatment previously performed if any, the type of oil, etc. In various embodiments, the crude oil is present in an amount of from about 1 to about 10,000 parts by weight per one million parts by weight of the combination of the oil and water. In other embodiments, the crude oil is present in an amount of from about 1 to about 200, about 10 to about 190, about 20 to about 180, about 30 to about 170, about 40 to about 160, about 50 to about 150, about 60 to about 140, about 70 to about 130, about 80 to about 120, about 90 to about 110, or about 90 to about 100 parts by weight per one million parts by weight of the combination of the oil and water. In yet other embodiments, the crude oil is present in an amount of from 200 to about 1000, about 300 to about 900, about 400 to about 800, about 500 to about 700, or about 500 to about 600 parts by weight per one million parts by weight of the combination of the oil and water. In various embodiments, the crude oil is present in an amount of from 1000 to about 5,000, about 1500 to about 4500, about 2000 to about 4000, about 2500 to about 3500, or about 2500 to about 3000 parts by weight per one million parts by weight of the combination of the oil and water. In other embodiments, the crude oil is present in an amount of from 5000 to about 10,000, about 5500 to about 9500, about 6000 to about 9000, about 6500 to about 8500, or about 7000 to about 8000 parts by weight per one million parts by weight of the combination of the oil and water. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those set forth above are expressly contemplated for use herein.

[0031] The combination of the oil and water typically includes water as the continuous phase. The water may be from various sources, e.g. from underground reservoirs, pore spaces of rock formations, fresh water, e.g. water pumped in hydraulic fracking operations, sea water from offshore drilling, etc. The water may also include, or be free of, dissolved minerals and salts, e.g. chloride salts such as NaCl, CaCh, MgCh, sulfate salts such as CaSCU, MgSCU, BaSCU, carbonate salts such as CaCCE, MgCCh, bicarbonate salts such as NaHCCh, Ca(HCO3)2, salts of iron, salts of manganese, salts strontium, salts of lithium, etc. Accordingly, the water may exhibit various salinities, e.g. from about 0 to about 500 g total dissolved solids (TDS) per liter of water. In various embodiments, the salinity of the water is from about 0 to about 10, about 1 to about 9, about 2 to about 8, about 3 to about 7, about 4 to about 6, or about 4 to about 5 g TDS per liter of water. InPCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PCvarious non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those set forth above are expressly contemplated for use herein.

[0032] The various amount of TDS in the water can also affect other chemical properties of the water, including pH, density, etc. For example, the water may have a pH that is acidic, neutral, or basic, typically from about 4 to about 9. In various embodiments, the water has a pH that is about 4, about 4.5, about 5, about 5.5, about 6, about 6.5, about 7, about 7.5, about 8, about 8.5, or about 9. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those set forth above are expressly contemplated for use herein.

[0033] Depending on the amount of TDS present in the water, the water may exhibit various densities, typically of from about 1 to about 1.3 g / cm3, about 1 to about 1.1 g / cm3, about 1 to about 1.2 g / cm3, about 1 to about 1.3 g / cm3, about 1.1 to about 1.2 g / cm3, about 1.1 to about 1.3 g / cm3, or about 1.2 to about 1.3 g / cm3. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those set forth above are expressly contemplated for use herein.

[0034] The water may be present in various amounts, typically from about 90 and up to about less than about 100 wt%, based on a total weight of the combination of the oil and water. In various embodiments, the water is present in an amount of from about 90 and up to about less than about 100 wt%, about 90 to about 99 wt %, about 91 to about 98 wt %, about 92 to about 97 wt %, about 93 to about 96 wt %, or about 94 to about 95 wt %, based on a total weight of the combination of the oil and water. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those set forth above are expressly contemplated for use herein.

[0035] The method may be, include, consist essentially of, or consist of, the step of adding colloidal silica to the combination of oil and water; and the step of adding a separating agent to the combination of oil and water simultaneously with, prior to, and / or subsequent to adding the colloidal silica to the combination of oil and water, thereby effecting at least partial separation of the oil and the water. The terminology “consist essentially of’ describes an embodiment that is free of any additional method step such as adding one or more additional surfactants, polymers, additives, etc. to the combination.PCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PCAdding Colloidal Silica to the Combination of Oil and Water

[0036] The method includes the aforementioned step of adding colloidal silica to the combination of oil and water. This forms a mixture or what may be alternatively described as a “second” or “separate” combination. The terminology “mixture”, “combination”, or “second combination” as used below, may describe the combination of the oil and water or may alternatively describe the combination the oil and water and the colloidal silica. Even further, the terminology “mixture”, “combination”, or “second combination” may describe the combination of the oil, the water, the colloidal silica, and the separating agent, and optionally any one or more additive or other components.

[0037] Alternatively, the step of adding may be described as contacting the combination of oil and water with the colloidal silica. Such contact can occur in a variety of forms, such as by introduction of a “pill” or “slug” of the colloidal silica through a treatment line or conduit, such as is known to those skilled in the art in the treatment of produced hydrocarbons from subterranean oil and gas wells, or by continuous injection procedures via a pump. The method may involve an injection procedure wherein the colloidal silica can be continuously, or incrementally, introduced wherein an operator can adjust the pump speed based on conditions

[0038] The colloidal silica may be added using any mechanism known in the art. For example, the colloidal silica may be added in a batch or continuous process and may be stirred, mixed, or combined using any method known in the art. In various embodiments, it is contemplated that the colloidal silica may additionally, or alternatively, added to the oil itself, the water itself, and / or to the combination of the oil and the water.Colloidal Silica

[0039] The colloidal silica itself is not particularly limited and may be any type known in the art. The colloidal silica may be alternatively described as colloidal silica particles. The colloidal silica may include, or be free of, organic silane modification. The colloidal silica can be present as a silica sol. Colloidal silica particles and silica sols can be derived from e.g. precipitated silica, micro silica (silica fume), pyrogenic (fumed silica), silanes, siloxane, or silica gels with sufficient purity. The terms "colloidal silica particles" and "silica sol" used herein can also include e.g. aluminium-modified and boron-modified silica particles and sols. Boron-modified silica sols are further described in e.g. US 2,630,410, which is expressly incorporated herein by reference in various non-limiting embodiments.PCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PC

[0040] If utilized, the aluminium modified silica particles typically have an AI2O3 content of from about 0.05 to about 3, about 0.05 to about 0.1, about 0.1 to about 3, about 0.1 to about 2, about 0.1 to about 1, about 0.5 to about 3, about 0.5 to about 2.5, about 1 to about 2, about 1.5 to about 2, about 2 to about 3, etc. wt%. The procedure of preparing an aluminium modified silica sol is further described e. g. in "The Chemistry of Silica", by Iler, K. Ralph, pages 407-409, John Wiley & Sons (1979) and in US 5 368 833, each of which are expressly incorporated herein by reference in various non-limiting embodiments. It is expressly contemplated that all values and ranges of values, both whole and fractional, including and between all of those set forth above, may be used herein in various non-limiting embodiments.

[0041] In various embodiments, the colloidal silica particles have an average particle size of from about 2 to about 150, about 5 to about 150, about 10 to about 145, about 15 to about 140, about 20 to about 135, about 25 to about 130, about 30 to about 125, about 35 to about 120, about 40 to about 115, about 45 to about 110, about 50 to about 105, about 55 to about 100, about 60 to about 95, about 65 to about 90, about 70 to about 85, about 75 to about 80, about 5 to about 150, or about 10 to about 40, nm It is expressly contemplated that all values and ranges of values, both whole and fractional, including and between all of those set forth above, may be used herein in various non-limiting embodiments.

[0042] The colloidal silica particles do not typically have a particularly narrow particle size distribution, i.e. with a low relative standard deviation of the particle size. The relative standard deviation of the particle size distribution is the ratio between the mean particle size by numbers and the standard deviation of the particle size distribution. The relative standard deviation of the particle size distribution may be lower than about 60, 55, 50, 45, 40, 35, 30, 25, 20, 15, 10, or 5 % by numbers. In various embodiments, the colloidal silica particles have a specific surface area from about 20 to about 1200, about 20 to about 1150, about 20 to about 1100, about 20 to about 1050, about 20 to about 1000, about 40 to about 600, about 60 to about 500, about 50 to about 1000, about 100 to about 950, about 150 to about 900, about 200 to about 850, about 250 to about 800, about 300 to about 750, about 350 to about 700, about 400 to about 650, about 450 to about 600, or about 500 to about 550, m2 / g. In other embodiments, the surface area is from about 300 to about 1200, about 300 to about 1150, about 300 to about 1100, about 300 to about 1050, about 300 to about 1000, about 350 to about 950, about 400 to about 900, about 450 to about 850, about 500 to about 800, about 550 to about 750, about 600 to about 700, or about 650, m2 / g. In otherPCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PCembodiments, the surface area is from about 1000 to about 1200, about 1050 to about 1150, or about 1100, m2 / g. The specific surface area, particle size, and particle size distribution can be determined using the Sears titration, as for instance described in G. W. Sears, Analytical Chemistry, Volume 28 (12), pp. 1981-1983. It is expressly contemplated that all values and ranges of values, both whole and fractional, including and between all of those set forth above, may be used herein in various non-limiting embodiments.

[0043] The colloidal silica particles may or may not be dispersed in a solvent, which may be water, in presence of stabilising cations such as K+, Na+, Li+, NH4+, organic cations, quaternary, tertiary, secondary, and primary amines, or mixtures thereof so as to form an aqueous silica sol. However, other dispersions such as organic solvents, e.g. lower alcohols, acetone or mixtures thereof, may be used to prepare organic silica sols. In various embodiments, the colloidal silica particles may be dispersed in a solvent in a concentration from about 1 to about 70, about 5 to about 60, 10 to about 50, about 15 to about 45, about 20 to about 40, about 25 to about 35, or about 30 to about 35, wt% counted as dry weight silica. The pH of such a dispersion may be from about 1 to about 12, or about 7 to about 11. A high silica content may be utilized as long as the colloidal silica particles remain stable without immediate substantial aggregation and / or gelation. It is expressly contemplated that all values and ranges of values, both whole and fractional, including and between all of those set forth above, may be used herein in various non-limiting embodiments.

[0044] In other embodiments, the colloidal silica has an S-value of less than about 75, 70, 65, 60, 55, 50, 45, 40, 35, 30, 25, 20, 15, 10, or 5. In various embodiments, the S-value is from about 5 to about 75, about 10 to about 70, about 15 to about 65, about 20 to about 60, about 25 to about 55, about 30 to about 50, about 35 to about 45, about 45 to about 50, about 50 to about 75, about 55 to about 70, or about 60 to about 65. The S-value described an extent of aggregation of colloidal silica particles, i. e. the degree of aggregate or microgel formation. The S-value can be measured and calculated according to the formulas given in Iler, R. K. & Dalton, R. L. in J. Phys. Chem. ;60 (1956), 955-957. The S-value is dependent on the silica content, the viscosity, and the density of the colloidal silica. A high S-value indicates a low microgel content. The S-value represents the amount of SiCE in percent by weight present in the disperse phase of e.g. a silica sol. The degree of microgel can be controlled during the production process as further described in e.g. US 5,368,833. It is expressly contemplated that all values and ranges of values, both whole andPCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PCfractional, including and between all of those set forth above, may be used herein in various nonlimiting embodiments.

[0045] In one embodiment, the colloidal silica has a surface area of from about 80 to about 1500, about 85 to about 1500, about 90 to about 1500, about 95 to about 1500, about 100 to about 1500, about 105 to about 1500, about 110 to about 1500, about 115 to about 1500, about 120 to about 1500, about 125 to about 1500, about 130 to about 1500, about 135 to about 1500, about 140 to about 1500, about 145 to about 1500, or about 150 to about 1500 m2 / g. In other embodiments, the surface area is from about 150 to about 1500, from about 200 to about 1450, from about 250 to about 1400, from about 300 to about 1350, from about 350 to about 1300, from about 400 to about 1250, from about 450 to about 1200, from about 500 to about 1150, from about 550 to about 1100, from about 600 to about 1050, from about 650 to about 1000, from about 700 to about 950, from about 750 to about 900, from about 800 to about 850, m2 / g. It is expressly contemplated that all values and ranges of values, both whole and fractional, including and between all of those set forth above, may be used herein in various non-limiting embodiments.

[0046] In another embodiment, the colloidal silica has an S-Value of less than about 75. In a further embodiment, the colloidal silica is aluminum modified and has an AI2O3 content of from about 0.05 to about 3 wt%. It is expressly contemplated that all values and ranges of values, both whole and fractional, including and between all of those set forth above, may be used herein in various non-limiting embodiments.

[0047] In various embodiments, the colloidal silica has a solids or actives content of from about 5 to about 50, about 10 to about 45, about 15 to about 40, about 20 to about 35, or about 25 to about 30, percent. In other embodiments, the colloidal silica has about 5 to about 15, about 5 to about 10, or about 10 to about 15, wt% of SiCE. It is expressly contemplated that all values and ranges of values, both whole and fractional, including and between all of those set forth above, may be used herein in various non-limiting embodiments.Silane Modified Colloidal Silica

[0048] In various additional embodiments, the modified colloidal silica is or includes colloidal silica particles in which the colloidal silica is modified with at least one organosilane moiety including a silicon atom bound to a carbon atom of an organic group. In other words, in various embodiments, at least a portion of surface silanol groups are replaced with one or more chemically bound organosilane groups.PCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PC

[0049] The chemically bound organosilane groups can include a silicon atom attached to a group — Rm. From one to three — Rmgroups can be present on the silicon atom of the organosilane moiety. Typically, there are at most two — Rmgroups, and in various embodiments only one. Where there is more than one — Rmgroup, they can be the same as each other or different from each other.

[0050] The organosilane-functionalised colloidal silica can be made by conventional processes, as described for example in WO 2004 / 035473 and WO 2004 / 035474, each of which is expressly incorporated herein by reference in its entirety in various non-limiting embodiments.

[0051] In various embodiments, the organosilane-functionalised colloidal silica is formed from a reaction between an organosilane reactant, T4-ySi— [Rm]y, and one or more silanol groups on the silica surface, i.e. [SiCh]— OH groups. In the organosilane reactant, each T is can be independently chosen from Ci-6 alkoxy, Ci-6 haloalkoxy, hydroxy and halide. Other options are the use of siloxanes, e.g. of formula [Rm]bT3-bSi{-O-SiT2-c[Rm]c}a-O-SiT3-b[Rm]b where a is 0 or an integer of 1 or more, typically from 0 to 5, and b is from 1 to 3 and c is from 1 to 2. Other examples include disilazanes, of formula {[Rm]bT3-bSi]2-NH where b is from 1 to 3. Of the haloalkoxy groups, fluoro and chloro are optional halo substituents. Alkoxy groups and halides are often typical as the T species. Of the halides, chloride is a typical choice. Of the alkoxy groups, CM alkoxy groups, such as methoxy, ethoxy, propoxy or isopropoxy, are typical choices. In various embodiments, the organosilane reactant can undergo a prehydrolysis step, in which one or more T groups are converted to -OH, as described for example by Greenwood and Gevert, Pigment and Resin Technology, 2011, 40(5), pp 275-284. It is expressly contemplated that all values and ranges of values including and between all of those set forth above, may be used herein in various nonlimiting embodiments.

[0052] The organosilane reactant can react with a surface silanol group to form from one to three Si-O-Si links between the silica surface and the organosilane silicon atom, i.e. {[SiO2]— O— }4-y-z [T]zSi— [Rm]ywhere 4-y-z is from 1 to 3, and is usually of from 1 to 2. A corresponding number of T groups are removed from the organosilane as a result. For example, if T is an alkoxy unit, an alcohol will be produced.

[0053] It is also possible for at least a portion of the organosilane to be in a dimeric form or even oligomeric form before binding to the colloidal silica, i.e. where the two or more organosilane moieties are bound to each other through Si-O-Si bonds.PCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PC

[0054] The chemically bound organosilane groups can be represented by the formula [{S1O2}— O— ]4-y-z [Z]zSi— [Rm]y. The group { SiOi }— O— represents an oxygen atom on the silica surface. The organosilane silicon atom has at least one, and optionally up to three such bonds to the silica surface, i.e. 4-y-z is at least 1, and no more than 3. Group Z is optionally present, and z is of from 0 to 2. The organosilane silicon atom has from 1 to 3 [Rm] groups, i.e. y is from 1 to 3, typically from 1 to 2. Where there is more than one Rmgroup, they can be the same or different.

[0055] When z is not zero, the organosilane silicon can include unreacted T groups, and / or includes hydroxyl groups where the T group has been removed, for example through a hydrolysis reaction. Alternatively or additionally, an Si-O-Si link can be formed with the silicon atom of a neighbouring organosilane group. Thus, in the formula {[SiCE]— O— }4-y-z[Z]zSi— [Rm]y, group Z can (on each occurrence) be chosen from the groups defined under T above, and also from hydroxy groups and — O— [SiR111]’ groups where the [SiR111]’ group is a neighbouring organosilane group.

[0056] Rmis typically an organic moiety, and typically includes from 1 to 16 carbon atoms, for example from 1 to 12 carbon atoms, or from 1 to 8 carbon atoms. It is bound to the organosilane silicon by a direct C-Si bond. It is expressly contemplated that all values and ranges of values, including and between all of those set forth above, may be used herein in various non-limiting embodiments.

[0057] Where there is more than one Rmgroup (i.e. if y is greater than 1), then each Rmcan be the same or different.

[0058] Rmis typically chosen from alkyl, alkenyl, epoxy alkyl, aryl, heteroaryl, C1-6 alkylaryl and C1-6 alkylheteroaryl groups, optionally substituted with one or more groups chosen from ERn, isocyanate and isocyanurate.

[0059] In ERn, E is either not present, or is a linking group chosen from -O-, -S-, -OC(O)-, -C(O)-, -C(O)O-, -C(O)OC(O)-, -N(RP)-, -N(RP)C(O)-,-N(RP)C(O)N(RP)- and -C(O)N(RP)- where Rpis H or C1-6 alkyl. Typically, E is -O-, -N(Rp)- or -N(Rp)C(O)N(Rp)-.

[0060] Rnis typically linked to E, or directly to Rmif E is not present, and is chosen from halogen (typically F, Cl or Br), alkyl, alkenyl, aryl, heteroaryl, C1-3 alkylaryl and C1-3 alkylheteroaryl. Rncan optionally be substituted with one or more groups chosen from hydroxyl, halogen (typically F, Cl or Br), epoxy, -ORPor -N(RP)2 where each Rpis as defined above. If E is present, Rncan also be hydrogen.PCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PC

[0061] In the above, alkyl and alkenyl groups can be aliphatic, cyclic or can include both aliphatic and cyclic portions. Aliphatic groups or portions can be linear or branched. Where any group or substituent includes halogen, the halogen is typically chosen from F, Cl and Br.Some groups can undergo hydrolysis reactions under conditions experienced in the colloidal silica medium. Thus, groups containing moieties such as halide, acyloxy, (meth) aery loxy and epoxy groups can hydrolyse to form corresponding carboxyl, hydroxyl or glycol moieties.

[0062] In various embodiments, one or more Rmgroups are Cns alkyl, Cns haloalkyl, Cns alkenyl or Cns haloalkenyl, typically Ci-8 alkyl or Ci-8 alkenyl, with an optional halide (e.g. chloride) substituent. Examples include methyl, ethyl, chloropropyl, isobutyl, cyclohexyl, octyl and phenyl. These Ci-8 groups can, in various embodiments, be Ci-6 groups or, in further embodiments, Ci-4 groups. Longer carbon chains tend to be less soluble in aqueous systems, which makes synthesis of the organosilane-modified colloidal silicas more complex. It is expressly contemplated that all values and ranges of values, including and between all of those set forth above, may be used herein in various non-limiting embodiments.

[0063] In various embodiments, Rmcan be an alkyl isocyanate, for example propylisocyanate. Rmcan also include an isocyanurate moiety, for example it can be or include a propylisocyanurate moiety.

[0064] In typical embodiments, Rmis a hydrophilic moiety. In various embodiments, Rmis a hydrophilic moiety containing at least one group chosen from hydroxyl, thiol, carboxyl, ester, epoxy, acyloxy, ketone, aldehyde, glycol ether (such as typically polyglycol ether (PEG)), (meth)acryloxy, amino, amido, ureido, isocyanate or isocyanurate, typically hydroxyl, amino, glycol ether (such as typically polyglycol ether (PEG)), ureido or ethylene glycol silane, and even more typically hydroxyl, amino, ureido or ethylene glycol silane. In further embodiments, hydrophilic moieties include at least one heteroatom chosen from O and N, and include no more than three consecutive alkylene (-CH2-) groups linked together.

[0065] In various embodiments, Rmis a group including from 1 to 8 carbon atoms, e.g. a C1-8 alkyl group, and which additionally includes an ERnsubstituent where E is oxygen and Rnis chosen from optionally substituted C 1-8 -epoxy alkyl and C1-8 hydroxyalkyl. Alternatively, Rncan be optionally substituted alkylisocyanurate. Examples of such ERnsubstituents include 3-glycidoxypropyl and 2,3-dihydroxypropoxypropyL It is expressly contemplated that all values andPCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PCranges of values, including and between all of those set forth above, may be used herein in various non-limiting embodiments.

[0066] In various embodiments, Rmis a group including from 1 to 8 carbon atoms, e.g. a Cns alkyl group, and which additionally includes an ERnsubstituent where E is not present, and Rnis epoxyalkyl, for example an epoxycycloalkyl. An example of such an Rmgroup is beta-(3,4-epoxycyclohexyl)ethyl. The epoxy group can alternatively be two neighbouring hydroxyl groups, e.g. Rncan be a dihydroxyalkyl such as a dihydroxycycloalkyl, and Rmbeing (3,4-dihydroxycyclohexyl)ethyl. It is expressly contemplated that all values and ranges of values, including and between all of those set forth above, may be used herein in various non-limiting embodiments.

[0067] In various embodiments, where there is more than one Rmgroup on the Si atom of the organosilane, at least one is a Cns alkyl or alkenyl group. It is expressly contemplated that all values and ranges of values, including and between all of those set forth above, may be used herein in various non-limiting embodiments.

[0068] Examples of organosilane reactants that can be used to make such functionalised colloidal silica include octyl triethoxysilane; methyl triethoxysilane; methyl trimethoxysilane; tris-[3-(trimethoxysilyl)propyl]isocyanurate; 3-mercaptopropyl trimethoxysilane; beta-(3, 4-epoxycyclohexyl) -ethyl trimethoxysilane; silanes containing an epoxy group (epoxy silane), glycidoxy and / or a glycidoxypropyl group such as 3-(glycidoxypropyl) trimethoxy silane (which can also be known as trimethoxy[3-(oxiranylmethoxy)propyl] silane), 3 -glycidoxypropyl methyldiethoxysilane, (3 -glycidoxypropyl) triethoxy silane, (3-glycidoxypropyl) hexyltrimethoxy silane, beta-(3, 4-epoxycyclohexyl)-ethyltriethoxysilane; 3-methacryloxypropyl trimethoxysilane, 3 -methacryloxypropyl triisopropoxysilane, 3-methacryloxypropyl triethoxysilane, octyltrimethoxy silane, ethyltrimethoxy silane, propyltriethoxy silane, phenyltrimethoxy silane, 3-mercaptopropyltriethoxy silane, cyclohexyltrimethoxy silane, cyclohexyltriethoxy silane, dimethyldimethoxy silane, 3- chloropropyltriethoxy silane, 3 -methacryloxypropyltrimethoxy silane, i-butyltriethoxy silane, trimethylethoxy silane, phenyldimethylethoxy silane, hexamethyldisiloxane, trimethylsilyl chloride, ureidomethyltriethoxy silane, ureidoethyltriethoxy silane, ureidopropyltriethoxy silane, hexamethyldisilizane, and mixtures thereof. US 4927749 discloses further typical silanes which may be used herein.PCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PC

[0069] The most typical organosilanes include epoxy groups, for example epoxyalkyl silanes or epoxyalkyloxyalkyl silanes. Hydroxyl-substituted groups are also typical, for example hydroxy alkyl and hydroxy alkyloxy alkyl groups including one or more hydroxyl groups, e.g. 1 or 2 hydroxyl groups. Examples include organosilanes containing a glycidoxy, glycidoxypropyl, dihydropropoxy or dihydropropoxypropyl group. These can be derived from organosilane reactants such as (3-glycidoxypropyl)trimethoxysilane, (3-glycidoxypropyl)triethoxysilane and (3-glycidoxypropyl)methyldiethoxysilane. In the compositions of the disclosure, epoxy groups can hydrolyse to form corresponding vicinal diol groups. Therefore, the disclosure also encompasses the diol equivalents of the above epoxy group-containing compounds.

[0070] There can be more than one different organosilane in the modified (or “functionalised”) colloidal silica, for example where the organosilane-modified silica is produced by reacting a mixture of two or more organosilanes with colloidal silica, or by mixing two or more separately prepared organosilane-modified colloidal silicas.

[0071] The silane compounds can form stable covalent siloxane bonds (Si-O-Si) with the silanol groups. In addition, they can be linked to the silanol groups, e.g. by hydrogen bonds, on the surface of the colloidal silica particles. It is possible that not all silica particles become modified by organosilane. The proportion of colloidal silica particles that become functionalised with organosilane will depend on a variety of factors, for example the size of the silica particles and the available surface area, the relative amounts of organosilane reactant to colloidal silica used to functionalise the colloidal silica, the type of organosilane reactants used and the reaction conditions.

[0072] The degree of modification (DM) of silica surface by organosilane can be expressed according to the following calculation (Equation 1), in terms of the number of silane molecules per square nanometre of silica surface:Equation 1wherein:DM is the degree of surface modification in units of nnT2;A is Avogadro’s constant;Norganosiiane is the number of moles of organosilane reactant used;Ssiiica is the surface area of the silica in the colloidal silica, in m2g’1; and Msiiica is the mass of silica in the colloidal silica, in g.PCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PC

[0073] DM can be at least 0.8 molecules of silane per nm2, and is typically of from 0.8 to 4 molecules per nm2. Typical embodiments have DM of from 1 to 3, for example from 1 to 2. In the above equation 1, the surface area of the silica is conveniently measured by Sears titration. It is expressly contemplated that all values and ranges of values, including and between all of those set forth above, may be used herein in various non-limiting embodiments.

[0074] The colloidal silica can be described as a stable colloid. By “stable” is meant that the organosilane-functionalised colloidal silica particles dispersed in the (usually aqueous) medium does not substantially gel or precipitate within a period of at least 2 months, and typically at least 4 months, more typically at least 5 months at normal storage at room temperature (20°C).

[0075] Typically, the relative increase in viscosity of the silane-functionalised colloidal silica dispersion between its preparation and up to two months after preparation is lower than 100%, more typically lower than 50%, and most typically lower than 20%. It is expressly contemplated that all values and ranges of values, including and between all of those set forth above, may be used herein in various non-limiting embodiments.

[0076] Typically, the relative increase in viscosity of the silane-functionalised colloidal silica between its preparation and up to four months after preparation is lower than 200%, more typically lower than 100%, and most typically lower than 40%. It is expressly contemplated that all values and ranges of values, including and between all of those set forth above, may be used herein in various non-limiting embodiments.Adding a Separating Agent

[0077] The method also includes the step of adding a separating agent to the combination of oil and water simultaneously with, prior to, and / or subsequent to adding the colloidal silica to the combination of oil and water, thereby effecting at least partial separation of the oil and the water. In one embodiment, the separating agent is added simultaneously with the step of adding the colloidal silica to the combination of oil and water. In another embodiment, the separating agent is added before the step of adding the colloidal silica to the combination of oil and water. In another embodiment, the separating agent is added after the step of adding the colloidal silica to the combination of oil and water. Alternatively, the separating agent may be added before and during, during and after, or before and after, the step of adding the colloidal silica to the combination of oil and water. All combinations of addition are hereby expressly contemplated forPCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PCuse herein in various non-limiting embodiments. The step of adding the separating agent may be accomplished using any method known in the art. The step of adding may be alternatively described as mixing, pouring, injecting, combining, etc. The step of adding may occur batch wise or continuously, in one or more parts.

[0078] The colloidal silica and the separating agent may be added at any desired point during the treatment of the combination of the oil and water, such as prior to or at gravity settling equipment, flotation devices, filtration processes, sales lines, and the like. Because of variations in operating parameters, such as the type and quantity of oil or other hydrocarbon or other constituents, the amount and quantity of water, the clarification required, and other physical and chemical parameters, an exact but general level of required amounts of the separating agent can sometimes not be specified in advance. Those skilled in the art will recognize that known clarification and floc evaluation tests, may easily be used to determine the appropriate level of treatment for the particular application at hand.

[0079] In various embodiments, the separating agent is, includes, consists essentially of, or consists of a cellulose ether. The cellulose ether is typically soluble or dispersible in water. The cellulose ether may be described as a polymer derived from cellulose, which is a natural polysaccharide. Accordingly, the cellulose ether can be non-toxic, biocompatible and / or biodegradable.

[0080] The cellulose ether may be further described as soluble or dispersible in water. Additionally, the cellulose ether may be soluble or dispersible in other solvents and solvent systems, including but not limited to organic solvents, e.g. ethanol, methanol, propanol, acetone etc., or combinations of water and one or more organic solvents. The cellulose ether may also be soluble or dispersible in aqueous solutions that may include other water-soluble compounds, e.g. ionic compounds. The cellulose ether may also exhibit different solubility, which may be measured at various temperatures, using various techniques known in the art, e.g., using a standardized method such as ASTM D5546, ISO 25179:2018, etc., using a gravimetric method, a titration method, a spectroscopic method, a conductometric method, etc.

[0081] In various embodiments, the solubility of the cellulose in water at ambient conditions, e.g. about 25 °C and about 1 atm, measured using any of the aforementioned methods, is from about 5 to about 20 mg of the cellulose ether per mL of water. In other embodiments, the solubility of the cellulose ether is from about 5 to about 19, about 6 to about 18, about 7 to about 17, aboutPCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PC8 to about 16, about 9 to about 15, about 10 to about 14, about 11 to about 13, or about 11 to about 12 mg of the cellulose ether per mL of water. In various non-limiting embodiments, all values and ranges of values including and between those set forth above are expressly contemplated for use herein.

[0082] The cellulose ether has the structure (I) below:wherein each R1, R2and R3is independently H, a carboxymethyl group, a Cl -Cl 8 alkyl group, or a C2-C3 hydroxy alkyl group, so long as not all R1, R2and R3are H; and wherein n is from about 800 to about 10,000.

[0083] Each R1, R2and R3is independently H, a carboxymethyl group, a Cl -Cl 8 alkyl group, or a C2-C3 hydroxy alkyl group, so long as not all R1, R2and R3are H. In various embodiments, one of R1, R2and R3may be H. In other embodiments, one of R1, R2and R3may be a Cl -Cl 8 alkyl group, or a C2 to C17 group, a C3 to C16 group, a C4 to C15 group, a C5 to C14 group, a C6 to C13 group, a C7 to C12 group, a C8 to Cl 1 group, a C9 to CIO group, a Cl to C3 group, a Cl to C5 group, a C2 to C3 group, a C2 to C4 group, or a C2 to C5 group. In various embodiments, each R1, R2and R3is independently H, a C1-C5 alkyl group, or a C8-C18 alkyl group or a C2-C3 hydroxy alkyl group, so long as not all R1, R2and R3are H. In various non-limiting embodiments, all values and ranges of values including and between those set forth above are expressly contemplated for use herein.

[0084] In various other embodiments, one of R1, R2and R3may be a C2-C3 hydroxy alkyl group, which may be alternatively described as hydroxymethyl and hydroxyethyl, respectively.

[0085] In yet other embodiments, one of R1, R2and R3may be a carboxymethyl group. In various embodiments, each R1, R2and R3is independently H or a carboxymethyl group, which may be charge balanced by a counter ion, e.g. H+, Na+, Ca2+, Mg2+, etc., so long as at least one of R1, R2and R3is a carboxymethyl group, and the cellulose ether may be further described as aPCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PCcarboxymethyl cellulose. Typically, the carboxymethyl cellulose includes Na+as the counter ion and may be additionally described as carboxymethyl cellulose sodium salt.

[0086] In other embodiments, each R1, R2and R3is independently H or a methyl group, so long as at least one of R1, R2and R3is a methyl group, and the cellulose ether may be further described as methyl cellulose.

[0087] In various embodiments, one of R1, R2and R3is H, one of R1, R2and R3is a methyl group, and one of R1, R2and R3is a hydroxypropyl group, and the cellulose ether may be further described as hydroxypropyl methyl cellulose.

[0088] In other embodiments, one of R1, R2and R3is H, one of R1, R2and R3is an ethyl group, and one of R1, R2and R3is a hydroxypropyl group, and the cellulose ether may be further described as hydroxypropyl ethyl cellulose.

[0089] In yet other embodiments, one of R1, R2and R3is H, one of R1, R2and R3is a methyl group, and one of R1, R2and R3is a hydroxyethyl group, and the cellulose ether may be further described as hydroxyethyl methyl cellulose.

[0090] In other embodiments, one of R1, R2and R3is H, one of R1, R2and R3is a methyl group, and one of R1, R2and R3is a hydroxyethyl group, and the cellulose ether may be further described as hydroxyethyl methyl cellulose.

[0091] In various embodiments, one of R1, R2and R3is H, one of R1, R2and R3is an ethyl group, and one of R1, R2and R3is a hydroxyethyl group, and the cellulose ether may be further described as hydroxy ethyl ethyl cellulose.

[0092] In various other embodiments, one of R1, R2and R3is a methyl group, one of R1, R2and R3is an ethyl group, and one of R1, R2and R3is a hydroxyethyl group, and the cellulose ether may be further described as methyl ethyl hydroxyethyl cellulose.

[0093] In various non-limiting embodiments, other combinations of R1, R2and R3are expressly contemplated for use herein. In other non-limiting embodiments, one, two or multiple (three or more) combinations of R1, R2and R3are also expressly contemplated within one structure of the cellulose ether.

[0094] In various non-limiting embodiments, the combination of oil and water includes one cellulose ether. In other embodiments, the combination of oil and water includes two or multiple (three or more) cellulose ethers, so long as at least one cellulose ether is as described herein. In various embodiments, the combination of oil and water includes one cellulose ether of thisPCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PCdisclosure and one or more cellulose ethers not described herein. In other embodiments, the combination of oil and water includes one or more cellulose ethers of this disclosure.

[0095] Referring to n, n can be described as the number of repeating units of the cellulose ether. In various embodiments, n is from about 800 to about 10,000, about 800 to about 10,000, about 2000 to about 10,000, about 4000 to about 10,000, about 5000 to about 10,000, about 6000 to about 10,000, about 7000 to about 10,000, about 8000 to about 10,000, or about 9000 to about 10,000. In other embodiments, n is from about 1000 to about 3000, about 1100 to about 3900, about 1200 to about 3800, about 1300 to about 3700, about 1400 to about 3600, about 1500 to about 3500, about 1600 to about 3400, about 1700 to about 3300, about 1800 to about 3200, about 1900 to about 3100, about 2000 to about 3000, about 2100 to about 2900, about 2200 to about 2800, about 2300 to about 2700, about 2400 to about 2600, or about 2500 to about 2600. In yet other embodiments, n if from about 3000 to about 10,000, about 3500 to about 9500, about 4000 to about 9000, about 4500 to about 8500, about 5000 to about 8000, about 5500 to about 7500, or about 6000 to about 7000. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those set forth above are expressly contemplated for use herein.

[0096] The cellulose ether may be described as a derivative of a cellulose, and the structure of cellulose may be described as structure (I) when all of R1, R2and R3is H. In other words, the cellulose ether may be described as including repeating D-anhydroglucose units joined together by 0-1-4-glycosidic bonds and connected to pendant R1, R2, R3groups, which are first described above. Derivatization can be performed to alter the properties of the cellulose, e.g. solubility, viscosity, etc. and form the cellulose ether. Derivatization of the cellulose may alternatively be described as etherification, modification, or substitution of a hydroxyl group with an ether group.

[0097] The cellulose ether may also be described relative to an average degree of substitution (DS), which describes the average number of hydroxyl groups substituted with ether groups per repeating D-anhydroglucose unit. The repeating D-anhydroglucose unit may have up to three hydroxyl groups to substitute. Thus, the average DS may be from about greater than 0 and up to about 3. In various embodiments, the average DS is from about greater than 0 and up to about 3, about 0.1 to about 2.9 about 0.2 to about 2.8, about 0.3 to about 2.7, about 0.4 to about 2.6, about 0.5 to about 2.5, about 0.6 to about 2.4, about 0.7 to about 2.3, about 0.8 to about 2.2, about 0.9 to about 2.1, or about 1.0 to about 2.0, about 1.1 to about 1.9, about 1.2 to about 1.8, about 1.3 toPCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PCabout 1.7, about 1.4 to about 1.6, or about 1.5 to about 1.6. In various non-limiting embodiments, all values and ranges of values including and between those set forth above are expressly contemplated for use herein.

[0098] The cellulose ether may further be described relative to an average degree of molar substitution (MS). Unlike the DS, MS describes the average number of hydroxy alkyl groups per repeating D-anhydroglucose unit, which may also be from about greater than 0 to about 3. In various embodiments, the average MS is from about greater than 0 and up to about 3, about 0.1 to about 2.9 about 0.2 to about 2.8, about 0.3 to about 2.7, about 0.4 to about 2.6, about 0.5 to about 2.5, about 0.6 to about 2.4, about 0.7 to about 2.3, about 0.8 to about 2.2, about 0.9 to about 2.1, or about 1.0 to about 2.0, about 1.1 to about 1.9, about 1.2 to about 1.8, about 1.3 to about 1.7, about 1.4 to about 1.6, or about 1.5 to about 1.6. In various non-limiting embodiments, all values and ranges of values including and between those set forth above are expressly contemplated for use herein.

[0099] The cellulose ether may be described using various parameters such as pH, charge, viscosity, solubility, etc. For example, the cellulose ether may exhibit a pH that is acidic, neutral, or basic. The cellulose ether may exhibit a pH of from about 5 to about 9, e.g. about 5, about 5.5, about 6, about 6.5, about 7, about 7.5, about 8, about 8.5, or about 9. In various non-limiting embodiments, all values and ranges of values including and between those set forth above are expressly contemplated for use herein.

[0100] The cellulose ether may be free of charge and may be further described as non-ionic. Alternatively, the cellulose ether may have a negative charge, and may be further described as anionic, which may be charge balanced with a counter ion, as previously described.

[0101] The cellulose ether may exhibit various viscosities when disposed in a solvent system, e.g. water, an organic solvent e.g. ethanol, methanol, propanol, acetone etc., which may be dependent on the DS, the MS, and / or the value of n. The viscosity may be measured using any standardized method known in the art, e.g. ISO 17025, ISO 17034, ASTM D2196, ASTM D445, etc. Various analytical instruments and apparatus may also be used, e.g. a rotary viscometer such as a Brookfield viscometer, with a spindle speed of from about 4 to about 6 rpm, at about 20 to about 25 °C, and using a sheer rate of about 100 s’1. In various embodiments, the viscosity of the cellulose ether is determined using a solution of about 1 wt%, 2 wt%, 3 wt%, 4 wt%, or 5 wt% of the cellulose ether in the solvent system. In various embodiments, the viscosity of the cellulosePCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PCether, measured using any of the aforementioned method, is from about 1 to about 100,000 cP. In other embodiments, the viscosity of the cellulose ether is from about 1 to about 100 cP, about 10 to about 90 cP, about 20 to about 80 cP, about 30 to about 70 cP, about 40 to about 60 cP, or 50 to about 60 cP. In yet other embodiments, the viscosity of the cellulose ether is from about 100 to about 1,000 cP, about 200 to about 900 cP, about 300 to about 800 cP, about 400 to about 700 cP, or about 500 to about 600 cP. In other embodiments, the viscosity of the cellulose ether is from about 1,000 to about 10,000 cP, about 1,500 to about 9,500 cP, about 2,000 to about 9,000 cP, about 2,500 to about 8,500 cP, about 3,000 to about 8,000 cP, about 3,500 to about 7,500 cP, about 4,000 to about 7,000 cP, about 4,500 to about 6,500 cP, or about 5,000 to about 6,000 cP. In various other embodiments, the viscosity of the cellulose ether is from about 10,000 to about 100,000 cP, about 15,000 to about 95,000 cP, about 20,000 to about 90,000 cP, about 25,000 to about 85,000 cP, about 30,000 to about 80,000 cP, about 35,000 to about 75,000 cP, about 40,000 to about 70,000 cP, about 45,000 to about 65,000 cP, or about 50,000 to about 60,000 cP. In various nonlimiting embodiments, all values and ranges of values including and between those set forth above are expressly contemplated for use herein.

[0102] The cellulose ether may exhibit various weight average molecular weights (Mw), which may also be dependent on the DS and the value of n. Accordingly, the weight average Mwof the cellulose ether may be from about 15 kDa to about 1,500 kDa. In various embodiments, the weight average Mwof the cellulose ether is from about 15 to about 100 kDa, about 20 to about 95 kDa, about 25 to about 90 kDa, about 30 to about 85 kDa, about 35 to about 80 kDa, about 40 to about 75 kDa, about 45 to about 70 kDa, about 50 to about 65 kDa, or about 55 to about 60 kDa. In other embodiments, the weight average Mwof the cellulose ether is from about 100 to about 700 kDa, about 150 to about 650 kDa, about 200 to about 600 kDa, about 250 to about 550 kDa, about 300 to about 500 kDa, about 350 to about 450 kDa, or about 350 to about 400 kDa. In yet other embodiments, the weight average Mwof the cellulose ether is from about 700 to about 1,500 kDa, about 750 to about 1,450 kDa, about 800 to about 1,400 kDa, about 850 to about 1,350 kDa, about 900 to about 1,300 kDa, about 950 to about 1,250 kDa, about 1,000 to about 1,200 kDa, about 1,050 to about 1,150 kDa, or about 1,050 to about 1,100 kDa. In various non-limiting embodiments, all values and ranges of values including and between those set forth above are expressly contemplated for use herein.PCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PC

[0103] The cellulose ether may be used in a small dosage and be present in the combination of oil and water in an amount of from about 0.05 to about 100, about 1 to about 100, about 0.06 to about 0.09, about 0.07 to about 0.08, about 5 to about 95, about 10 to about 90, about 15 to about 85, about 20 to about 80, about 25 to about 75, about 30 to about 70, about 35 to about 65, about 40 to about 60, about 45 to about 55, about 45 to about 50, about 1 to about 20 parts by weight per one million parts by weight of the combination. In various embodiments, the cellulose ether is present in amount of from about 1 to about 20, about 2 to about 19, about 3 to about 18, about 4 to about 17, about 5 to about 16, about 6 to about 15, about 7 to about 14, about 8 to about 13, about 9 to about 12, about 10 to about 11 parts by weight per one million parts by weight of the combination. In various non-limiting embodiments, all values and ranges of values including and between those set forth above are expressly contemplated for use herein.

[0104] Referring back, the amount of colloidal silica that is present, relative to a total weight of the combination of oil and water, can be from about 0.05 to about 100, about 1 to about 100, about 0.06 to about 0.09, about 0.07 to about 0.08, about 5 to about 95, about 10 to about 90, about 15 to about 85, about 20 to about 80, about 25 to about 75, about 30 to about 70, about 35 to about 65, about 40 to about 60, about 45 to about 55, about 45 to about 50, about 0.05 to about 30, about 0.05 to about 25, about 0.05 to about 20, about 0.05 to about 15, about 0.05 to about 10, about 0.05 to about 5, about 0.05 to about 1, about 0.05 to about 0.1, about 0.1 to about 30, about 0.1 to about 25, about 0.1 to about 20, about 0.1 to about 15, about 0.1 to about 10, about 0.1 to about 5, about 0.1 to about 1, about 1 to about 30, about 1 to about 25, about 1 to about 20, about 1 to about 15, about 1 to about 10, about 1 to about 5, about 5 to about 30, about 5 to about 25, about 5 to about 20, about 5 to about 15, about 5 to about 10, about 10 to about 30, about 10 to about 25, about 10 to about 20, about 10 to about 15, about 15 to about 30, about 15 to about 25, about 15 to about 20, about 20 to about 30, about 20 to about 25, or about 25 to about 30, weight percent actives based on one million parts by weight of the combination of oil and water. It is expressly contemplated that all values and ranges of values, both whole and fractional, including and between all of those set forth above, may be used herein in various non-limiting embodiments.

[0105] In other embodiments, the amount of the separating agent present, relative to a total weight of the combination of oil and water, can be from about 0.1 to about 75, about 0.1 to about 50, about 0.1 to about 40, about 0.1 to about 30, about 0.1 to about 25, about 0.1 to about 20, about 0.1 to about 15, about 0.1 to about 10, about 0.1 to about 5, about 0.1 to about 1, about 1 to aboutPCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PC75, about 1 to about 50, about 1 to about 40, about 1 to about 30, about 1 to about 25, about 1 to about 20, about 1 to about 15, about 1 to about 10, about 1 to about 5, about 5 to about 75, about 5 to about 50, about 5 to about 40, about 5 to about 30, about 5 to about 25, about 5 to about 20, about 5 to about 15, about 5 to about 10, about 10 to about 75, about 10 to about 50, about 10 to about 40, about 10 to about 30, about 10 to about 25, about 10 to about 20, about 10 to about 15, about 15 to about 75, about 15 to about 50, about 15 to about 40, about 15 to about 30, about 15 to about 25, about 15 to about 20, about 20 to about 75, about 20 to about 50, about 20 to about 40, about 20 to about 30, about 20 to about 25, about 25 to about 75, about 25 to about 50, about 25 to about 40, about 25 to about 30, about 30 to about 75, about 30 to about 50, about 30 to about 40, about 40 to about 75, about 40 to about 50, or about 50 to about 75, weight percent actives based on one million parts by weight of the combination of oil and water. It is expressly contemplated that all values and ranges of values, both whole and fractional, including and between all of those set forth above, may be used herein in various non-limiting embodiments.

[0106] In still other embodiments, the separating agent may be present in the combination in an amount of from about 0.05 to about 20 weight percent actives based on one million parts by weight of the combination; and the separating agent may be present in the oil and water combination in an amount of from about 0.2 ppm to about 50 weight percent actives based on one million parts by weight of the combination. For example:the amount of colloidal silica present, relative to a total weight of the combination of oil and water, may be from about 0.05 to about 30, about 0.05 to about 25, about 0.05 to about 20, about 0.05 to about 15, about 0.05 to about 10, about 0.05 to about 5, about 0.05 to about 1, about 0.1 to about 20, about 0.1 to about 15, about 0.1 to about 10, about 0.1 to about 5, about 0.1 to about 1, about 1 to about 30, about 1 to about 25, about 1 to about 20, about 1 to about 15, about 1 to about 10, about 1 to about 5, about 5 to about 20, about 5 to about 15, about 5 to about 10, about 10 to about 20, or about 10 to about 15, weight percent actives based on one million parts by weight of the combination of oil and water;while at the same time,the amount of the separating agent present, relative to a total weight of the combination of oil and water, may be from about 0.2 ppm to about 50, about 0.2 ppm to about 40, about 0.2 ppm to about 30, about 0.2 ppm to about 25, about 0.2 ppm to about 20, about 0.2 ppm to about 15, about 0.2 ppm to about 10, about 0.2 ppm to about 5, about 0.2 ppm to about 1, about 1 to aboutPCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PC50, about 1 to about 40, about 1 to about 30, about 1 to about 25, about 1 to about 20, about 1 to about 15, about 1 to about 10, about 1 to about 5, about 5 to about 50, about 5 to about 40, about 5 to about 30, about 5 to about 25, about 5 to about 20, about 5 to about 15, about 5 to about 10, about 10 to about 50, about 10 to about 40, about 10 to about 30, about 10 to about 25, about 10 to about 20, about 10 to about 15, about 15 to about 50, about 15 to about 40, about 15 to about 30, about 15 to about 25, about 15 to about 20, about 20 to about 50, about 20 to about 40, about 20 to about 30, about 20 to about 25, about 25 to about 50, about 25 to about 40, about 25 to about 30, about 30 to about 50, about 30 to about 40, or about 40 to about 50, weight percent actives based on one million parts by weight of the combination of oil and water. It is expressly contemplated that all values and ranges of values, both whole and fractional, including and between all of those set forth above, may be used herein in various non-limiting embodiments.

[0107] The method may also include, or be free of, the step of heating the combination of any one or more of the components, e.g. the oil, the water, the colloidal silica, the separating agent, any additives, and / or any combination of one or more of the above. The step of heating may be further defined as heating to a temperature of from about 25 to about 100, about 30 to about 95, about 35 to about 90, about 40 to about 85, about 45 to about 80, about 50 to about 75, about 60 to about 70, or about 65 to about 70, °C. It is expressly contemplated that all values and ranges of values, both whole and fractional, including and between all of those set forth above, may be used herein in various non-limiting embodiments.Additional Embodiments of the Method

[0108] In alternative embodiments, the disclosure also provides a method of separating crude oil and water. The method includes the steps of providing an O / W emulsion including crude oil and water; providing the colloidal silica; providing the separating agent, and combining the emulsion, the colloidal silica, and the separating agent.

[0109] The method of separating the crude oil and the water may be further described as clarifying the water, isolating crude oil and water, treating the water, etc. The method of separating the crude oil and the water can include the step of providing the O / W emulsion including crude oil and water. The step of providing the O / W emulsion may be any in the art and is not particularly limited. For example, the O / W emulsion may be provided by combining crude oil with water. Alternatively, the O / W emulsion may be provided or obtained from various sources, e.g. directlyPCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PCfrom oilfield processes, from previous processes, from a storage pond, etc. The step of providing the O / W emulsion may be performed in one or more steps, in a batch or continuous process, etc.

[0110] The method can also include the step of providing the colloidal silica and / or providing the separating agent, each of which may be procured from a commercial or an internal source. The steps of providing may also be performed in one or more steps, in a batch or continuous process, etc. The steps of providing may be performed in any order. Each may be provided in part or in whole, and in any physical form known in the art, e.g. in a solid form, e.g. solid pellets, powder, etc., in a solution form, e.g. a liquid concentrate, a solution in water, etc., and / or as a paste, a slurry, etc.

[0111] The step of combining may be any known in the art and is not particularly limited. For example, the step of combining may be described as adding the colloidal silica and / or separating agent into the O / W emulsion, e.g. manually, using a chemical pump, using an automatic system, etc. The step of combining may be performed in various apparatus or container, e.g. in a well, in a tank, in a process flow, in a multi-step treatment system, etc. The step of combining may further include a step of mixing using various techniques and equipment, e.g. a mechanical agitator, a blender, a jet mixer, a circulating pump, etc. Additionally, the step of combining may include an optional step of heating or providing additional pressure which may help increase the efficiency of the separation.

[0112] Subsequent to the step of combining, the crude oil and the water may be separated. The terminology “separate,” “separating,” “separated,” and / or “separation” may or may not indicate a physical removal of the crude oil from the water. For example, the crude oil may aggregate and / or float on top of the water. Thus, the crude oil may not be suspended in the water or considered a component of the O / W emulsion, but may still be in direct contact with, or exposed to, the water, any residual O / W emulsion, etc. The step of separating the crude oil from the water may additionally and optionally include physically removing the crude oil, which may be performed using various tools and techniques, e.g. using a skimmer such as a weir skimmer, a drum skimmer, a tube skimmer, using absorbent particles or absorbent pads, or a separator utilizing more than one oil removal techniques, e.g. an API separator, a corrugated plate interceptor (CPI) separator, etc.

[0113] The step of separation can be used to decrease the amount of the crude oil suspended in the water. Typically, before the step of combining, the crude oil may be present in the O / WPCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PCemulsion in an amount of from about 1000 to about 10,000 parts by weight per one million parts by weight of the OAV emulsion.

[0114] A significant amount of the crude oil, e.g. about 80 and up to less than about 100 wt% of the crude oil may aggregate and be separated from the water. In various embodiments, about 80 to about 99 wt%, about 81 to about 98 wt%, about 82 to about 97 wt%, about 83 to about 96 wt%, about 84 to about 95 wt%, about 85 to about 94 wt%, about 86 to about 93 wt%, about 87 to about 92 wt%, about 88 to about 91 wt%, or about 89 to about 90 wt% of the crude oil may aggregate and be separated from the water. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those set forth above are expressly contemplated for use herein.

[0115] Hence, after the step of separating, the combination, composition, emulsion, etc. may be described as free of the crude oil. Alternatively, a minimal amount of residual crude oil may remain in the water as the OAV emulsion. Accordingly, the amount of residual crude oil present in the OAV emulsion and the amount of residual crude oil present may also decrease after the step of separating. The amount of residual crude oil in water may be measured using various methods, e.g. using a digital oil in water analyzer instrument. Conditions and settings of such instruments may vary, e.g. output signals of from about 0 to about 20 mA, at a temperature of about 1 to about 40 °C, using a supply frequency of from about 50 to about 60 Hz, etc. In various embodiments, the residual crude oil, measured using any of the aforementioned conditions, is present in an amount of from about 1 to about 200 parts by weight per million parts by weight of the combination, composition, emulsion, etc.. In other embodiments, the residual crude oil is present in an amount of from about 1 to about 30, about 2 to about 29, about 3 to about 28, about 4 to about 27, about 5 to about 26, about 6 to about 25, about 7 to about 24, about 8 to about 23, about 9 to about 22, about 10 to about 21, about 11 to about 20, about 12 to about 19, about 13 to about 18, about 14 to about 17, or about 15 to about 16 parts by weight per million parts by weight of the combination, composition, emulsion, etc.. In yet other embodiments, the residual crude oil is present in an amount of from about 30 to about 200, about 40 to about 190, about 50 to about 180, about 60 to about 170, about 70 to about 160, about 80 to about 150, about 90 to about 140, about 100 to about 130, or about 110 to about 120 parts by weight per million parts by weight of the combination, composition, emulsion, etc. In various non-limiting embodiments, all values andPCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PCranges of values, both whole and fractional, including and between those set forth above are expressly contemplated for use herein.Use of the Method

[0116] The method can be used in any industry and in any application. In various embodiments, the method may be conducted in an apparatus chosen from a free water knockout, a dissolved air flotation unit, a skim tank, a water clarifier, a sludge dewatering belt press, oilfield platforms, and combinations thereof. In other embodiments, the method may be conducted in an apparatus chosen from a free water knockout (FWKO) unit, dissolved air flotation (DAF) unit, skim tank, water clarifier, sludge dewatering belt press, oilfield platforms, induced gas flotation (IGF) unit, corrugated plate interceptor (CPI) separator, hydrocyclone separator, electrocoagulation unit, coalescing plate separator, gravity separation tank, API oil-water separator, multiphase separator, flotation cell, membrane filtration system, slop oil treatment system, produced water reinjection (PWRI) system, sludge centrifuge, decanter centrifuge, sand filter system, activated carbon adsorption unit, hydrophilic membrane filtration unit, reverse osmosis (RO) system, evaporation system, desalter unit, three-phase separator, heater treater, tilted plate separator (TPS), settling basin, mechanical skimmer, vacuum belt filter, sludge drying bed, oil- water coalescer, produced treatment skid, offshore production facility, onshore separation facility, and combinations thereof. Moreover, the method may be utilized in an Enhanced Oil Recovery (EOR) process and / or Steam Assisted Gravity Drainage (SAGD) process.

[0117] In an oilfield, there are online meters that measure the oil content of the water. In one non-limiting embodiment, it is suitable for the oil in the treated or clarified water to be below 5 ppm of oil. In the laboratory, hexane extractions may be used to measure the amount of oil in the water. The methods and compositions herein may find beneficial use in oil-in-water emulsion separation (breaking), industrial and municipal wastewater clarification and sludge dewatering. The methods and compositions described herein can be effective in a wider range of operations and maintains its performance under difficult conditions, for instance at a wider range of temperatures, where lower temperatures are more difficult to treat, and wider ranges of oil content where the higher the oil content, the more difficult the combination is to treat. In one non-limiting embodiment the temperature may be from about 100 to about 300° F. (about 38 to about 149° C.), alternatively from about 150 to about 200° F. (about 65 to about 93° C.). Further, the methods and compositions described herein are able to tolerate slugs of chemicals that occasionally flowPCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PCthrough the system, including, but not necessarily, chemicals (e.g. from drilling fluids, corrosion inhibitors, scale inhibitors, and the like) and minerals (e.g. diatomaceous earth and iron sulfide). “Slug” as used in this context means a relatively high concentration of the chemical or impurities such as minerals.

[0118] It is contemplated that the effectiveness of the separation, e.g. the separation method, may be from about 1 to about 100, about 5 to about 95, about 10 to about 90, about 15 to about 80, about 20 to about 75, about 25 to about 70, about 30 to about 65, about 35 to about 60, about 40 to about 55, about 50, about 55, about 60, about 65, about 70, about 75, about 80, about 85, about 90, or about 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100, percent. The terminology “effectiveness of the separation” may be defined as the weight percent of the original amount of oil in the combination that is separated from the water in the combination, wherein 100 percent would be indicative of total separation of all of the original amount of oil in the combination. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those set forth above are expressly contemplated for use herein.Composition

[0119] This disclosure also provides a composition itself that includes the colloidal silica and the separating agent. The amounts and type of the colloidal silica and the separating agent may be as described herein. In various embodiments, the composition is, includes, consists essentially of, or consists of, the colloidal silica and the separating agent. The terminology “consists essentially of’ describes that the composition may be free of polymers, monomers, solvents, additives, inorganic compounds, silicas that are not described herein, or any component described as optional herein, etc.

[0120] In various embodiments, the composition includes from about 0.1 to about 99.9, about 0.5 to about 99.5, about 1 to about 99, about 5 to about 90, about 10 to about 80, about 15 to about 75, about 20 to about 70, about 25 to about 65, about 30 to about 60, about 35 to about 55, about 40 to about 50, about 50 to about 99, about 50 to about 90, about 50 to about 80, about 50 to about 70, about 50 to about 60, about 60 to about 99, about 60 to about 90, about 60 to about 80, about 60 to about 70, about 70 to about 99, about 70 to about 90, about 70 to about 80, about 80 to about 99, about 80 to about 90, or about 90 to about 99, weight percent of the colloidal silica based on a total weight of the composition. This weight percent may describe the weight of the silica itself or may describe the weight of a solution of the silica in a solvent such as water. InPCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PCvarious non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those set forth above are expressly contemplated for use herein.

[0121] Similarly, in other embodiments, the composition includes from about 0.1 to about 99.9, about 0.5 to about 99.5, about 1 to about 99, about 5 to about 90, about 10 to about 80, about 15 to about 75, about 20 to about 70, about 25 to about 65, about 30 to about 60, about 35 to about 55, about 40 to about 50, about 50 to about 99, about 50 to about 90, about 50 to about 80, about 50 to about 70, about 50 to about 60, about 60 to about 99, about 60 to about 90, about 60 to about 80, about 60 to about 70, about 70 to about 99, about 70 to about 90, about 70 to about 80, about 80 to about 99, about 80 to about 90, or about 90 to about 99, weight percent of the separating agent based on a total weight of the composition. This weight percent may describe the weight of the separating agent itself or may describe the weight of a solution of the separating agent in a solvent such as water. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those set forth above are expressly contemplated for use herein.Emulsion

[0122] This disclosure further provides an emulsion itself that includes oil, water, the colloidal silica, and the separating agent. The emulsion may be of any type known in the art or any type described herein. The weight percents of the oil, water, colloidal silica, and separating agent may also be any described herein.

[0123] After formation, the emulsion may have a clarity rating of from about 1 to about 10, wherein 1 is the best and 10 is the worst. This is measured using a line chart, as is appreciated in the art, wherein the finest line is placed on top because the oil separation starts from the bottom and move upwards.Optional Additives

[0124] The methods, combinations, compositions, and / or emulsions of this disclosure may utilize, or be free of, or include less than 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0.5, 0.1, 0.05, or 0.01, weight percent, based on a total weight of the combination of water and oil, the colloidal silica, the separating agent, the composition, and / or the emulsion, of any one or more of the following: cationic compounds such as cationically-modified starches (such as com, potato, wheat, tapioca, rice, water soluble starches and guar gum (if cationically-modified), cationic polyacrylamides, zinc salts, aluminum salts, brine dispersant polymers (such as aluminum brine dispersion polymer),PCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PCinvert emulsion polymers (cationically-modified, water-soluble polymers such as copolymers of acrylamide and diallyl dimethylammonium chloride), polyamines, polyDADMACs (polydiallyldimethylammonium chlorides), polyethyleneimines, glyoxylated polyacrylamide, polyguanidine, methylene bis-acrylamide-methacryl-amide-propyl trimethyl-ammonium chloride (MAPTAC), acryloxyethyl trimethyl-ammonium chloride (AETAC), acrylamidopropyl trimethyl ammonium chloride (APTAC), acrylic latexes and dithiocarbamates (DTCs), melamine formaldehydes, guar gum, amine condensates and non-ionic polyacrylamides, crosslinked and non-crosslinked nonionic and anionic acrylic latex polymers, amine N-l (triethanolamine neutralized with glacial acetic acid or ethylenediamine polymerized with Epon 828 and then reacted with either carbon disulfide or zinc chloride, available from Huntsman Corporation), polymers having weight or number average molecular weight ranges from about 0.5 million independently to about 20 million, from about 1 independently to about 15 million, from about 4 million independently to about 10 million, from about 10,000 independently to about 100,000, Da, dithiocarbamates, hydrogen sulfide (H2S) scavengers, scale and corrosion inhibitors, antioxidants, demulsifiers, or the like, and / or combinations thereof, so long as the aforementioned separating agent is not excluded. In other embodiments, the method, composition, and / or emulsion of this disclosure may be free of, or include less than 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0.5, 0.1, 0.05, or 0.01, weight percent, based on a total weight of the combination of water and oil, the colloidal silica, the separating agent, the composition, and / or the emulsion, of any one or more of cationic chemicals, anionic chemicals, nonionic chemicals, amphoteric chemicals and / or combinations thereof, again so long as the separating agent of this disclosure is not excluded. It is expressly contemplated that all values and ranges of values, both whole and fractional, including and between all of those set forth above, may be used herein in various non-limiting embodiments.

[0125] In other embodiments, the methods, combinations, compositions, and / or emulsions may include, or be free of, additional components, which can be naturally present in an oilfield composition, produced from oilfield processes, or included for various purposes, e.g. further treating the water, preventing corrosion of oil field equipment, improving oil extraction, etc.

[0126] For example, the methods, combinations, compositions, and / or emulsions may include, or be free of, various dissolved gases, including but not limited to natural hydrocarbon gasses commonly found in oil reservoirs, e.g. methane, ethane, propane, butane, etc., carbon dioxide, which may be naturally present in oil reservoirs or included for applications, e.g. enhanced oilPCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PCrecovery (EOR), and other gasses that are naturally present in oil reservoirs in various amounts, e.g. hydrogen sulfide, nitrogen, helium, etc.

[0127] The methods, combinations, compositions, and / or emulsions may also include, or be free of, volatile organic compounds (VOCs), which may be toxic or non-toxic, chemically inert or active, and which are typically known in the art to include compounds such as benzene, toluene, ethylbenzene, xylene, chloroform, trichloroethylene, methanol, ethanol, acetone, formaldehyde, etc.

[0128] The methods, combinations, compositions, and / or emulsions may additionally and optionally include solids, in various sizes, shapes and types, typically suspended in the oilfield composition. For example, the solids may be sand, which may include of silt; clay, which may include kaolinite, illite, montmorillonite, etc., carbonates, e.g. calcite (CaCCh), dolomite (CaMglCChE), etc., and heavy minerals, which may include zircon, rutile, ilmenite, etc. The solids may or may not be from the oil reservoirs, which may be introduced to the oilfield composition through various oilfield processes. The solids may also be biological, e.g. microorganisms such as bacteria, algae, etc.

[0129] The additional components described above may be present in the methods, combinations, compositions, and / or emulsions in various amounts, depending on the oil reservoir, methods of oil extraction, treatment techniques, etc. Accordingly, the additional components may be present in an amount of from about 0 to about 10 parts by weight per million parts by weight of a composition, emulsion, combination, etc. In various embodiments, the solids are present in an amount of from about 0 to about 10, about 1 to about 9, about 2 to about 8, about 3 to about 7, about 4 to about 6, or about 4 to about 5 parts by weight per million parts by weight of the composition, emulsion, combination, etc. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those set forth above are expressly contemplated for use herein.

[0130] The additional components described above may be corrosive to various equipment employed in oilfield processes. Accordingly, an additive may be included, e.g. to treat the water and / or prevent corrosion. For example, the additive may be a corrosion inhibitor. Non-limiting examples of corrosion inhibitors include amine compounds that can adsorb onto surfaces of equipment, e.g. monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA), phosphonate compounds that can inhibit scale formation and / or provide corrosion protection byPCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PCchelating metal ions, e.g. aminotris methylenephosphonic acid (ATMP), ethylenediaminetetra methylenephosphonic acid (EDTMP), etc., other chelating agents, e.g. glutamic acid, N,N-diacetic acid, diethylenetriaminepentaacetic acid, etc., oxygen scavengers that can react with dissolved oxygen in the water to reduce oxygen-induced corrosion, e.g. hydrazine hydrate, methylhydrazine, etc. Additionally, the additive may be a biocide, which may be used to minimize microbial growth. Non-limiting examples of biocides include 2,2-dibromo-3-nitrilopropionamide (DBNPA), tetrakis (hydroxymethyl)phosphonium sulfate (THPS), glutaraldehyde, etc. The additive may also be a surfactant, which can be used for various purposes, e.g. attaining a desirable viscosity. Nonlimiting examples of surfactants include sorbitan esters, sodium dodecyl sulfate, cetyl trimethyl ammonium bromide, alkylbenzene sulfonates, alkylphenol ethoxylates, cocamidopropyl betaine, tallow amidoamine oxide, etc.

[0131] The additive may be present in the composition, combination, emulsion, etc. in an amount of from about 0 to about 10 parts by weight per million parts by weight of the total. In various embodiments, the additive is present in an amount of from about 0 to about 10, about 1 to about 9, about 2 to about 8, about 3 to about 7, about 4 to about 6, or about 4 to about 5 parts by weight per million parts by weight of the composition, combination, emulsion, etc. In various nonlimiting embodiments, all values and ranges of values, both whole and fractional, including and between those set forth above are expressly contemplated for use herein.Physical Properties:

[0132] The combinations, mixtures, compositions, and / or emulsions of this disclosure may exhibit various physical properties, including but not limited to viscosity, turbidity, density, pH, amount of crude oil, etc., which may depend on factors known to the skilled person.

[0133] Accordingly, the combinations, mixtures, compositions, and / or emulsions of this disclosure may exhibit various viscosities, typically from about 1.2 to about 2 mPas. In various embodiments, the viscosity is from about 1.2 to about 2 mPas, about 1.3 to about 1.9 mPas, about 1.4 to about 1.8 mPas, about 1.5 to about 1.7 mPas, or about 1.5 to about 1.6 mPas. The viscosity may be measured according to any method known in the art, as first described above. For example, such a method may be a standardized method known in the art, e.g. ISO 17025, ISO 17034, ASTM D2196, ASTM D445, etc., or using various analytical instruments and apparatus, e.g. a rotary viscometer such as a Brookfield viscometer, employing various settings. For example, a Brookfield viscometer may be used with a spindle speed of from about 4 to about 6 rpm, at aboutPCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PC20 to about 25 °C, and using a sheer rate of about 100 s’1. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those set forth above are expressly contemplated for use herein.

[0134] The combinations, mixtures, compositions, and / or emulsions of this disclosure may also exhibit various turbidities, which can be used to describe the amount of solids and / or oil droplets suspended in the oilfield composition which may lead to the oilfield composition appearing cloudy, murky, muddy, dark, heterogenous, etc. Alternatively, the combinations, mixtures, compositions, and / or emulsions of this disclosure may also have an appearance that is clear, transparent, etc. Accordingly, the combinations, mixtures, compositions, and / or emulsions may have various appearances, e.g. color, clarity, etc., which may depend on many factors. The turbidity may also be quantitatively evaluated using various methods known in the art. For example, a standardized method, e.g. D7315, ISO 7027, etc. may be used. Alternatively, various apparatus, e.g. a UV-Vis, a benchtop meter, a submersible meter, etc.

[0135] The combinations, mixtures, compositions, and / or emulsions of this disclosure may exhibit various densities, which may be measured using any methods known in the art, e.g. according to standardized methods such as ASTM D4052, ISO 12154:2014, etc., by using an apparatus such as a hydrometer, a Coriolis density meter, or calculated from the weight and volume of the oilfield composition, etc. In various embodiments, the density is from about 1 to about 1.5 g / cm3, about 1.1 to about 1.4 g / cm3, about 1.2 to about 1.3 g / cm3, or about 1 to about 1.1 g / cm3. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those set forth above are expressly contemplated for use herein.

[0136] The combinations, mixtures, compositions, and / or emulsions of this disclosure may be described as slightly acidic, neutral, or slightly basic, indicated by pH, which may be measured using any methods known in the art, e.g. using a pH meter, using a pH indicator solution, using a pH test strip, performing a titration, etc. In various embodiments, the pH is from about 4 to about 9. In various embodiments, the water has a pH that is about 4, about 4.5, about 5, about 5.5, about 6, about 6.5, about 7, about 7.5, about 8, about 8.5, or about 9. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those set forth above are expressly contemplated for use herein.

[0137] The combinations, mixtures, compositions, and / or emulsions of this disclosure may include a large amount of an emulsion, e.g. from about 90 and up to less than about 100 wt%,PCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PCbased on a total weight of the total. Accordingly, the amount of crude oil present may be the same as, or different from, the amount of crude oil present in the combinations, mixtures, compositions, and / or emulsions. In various embodiments, the crude oil is present in the combination, composition, and / or emulsion of this disclosure in an amount of from about 1 to about 10,000 parts by weight per million parts by weight of the total. In other embodiments, the crude oil is present in an amount of from about 1 to about 200, about 10 to about 190, about 20 to about 180, about 30 to about 170, about 40 to about 160, about 50 to about 150, about 60 to about 140, about 70 to about 130, about 80 to about 120, about 90 to about 110, or about 90 to about 100 parts by weight per one million parts by weight of the total. In yet other embodiments, the crude oil is present in an amount of from 200 to about 1000, about 300 to about 900, about 400 to about 800, about 500 to about 700, or about 500 to about 600 parts by weight per one million parts by weight of the total. In various embodiments, the crude oil is present in an amount of from 1000 to about 5,000, about 1500 to about 4500, about 2000 to about 4000, about 2500 to about 3500, or about 2500 to about 3000 parts by weight per one million parts by weight of the total. In other embodiments, the crude oil is present in an amount of from 5000 to about 10,000, about 5500 to about 9500, about 6000 to about 9000, about 6500 to about 8500, or about 7000 to about 8000 parts by weight per one million parts by weight of the total. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those set forth above are expressly contemplated for use herein.

[0138] It is contemplated that any method, combinations, mixtures, compositions, and / or emulsions of this disclosure may include or be free of, or include less than 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0.5, 0.1, 0.05, or 0.01, weight percent, based on a total weight of the combination of water and oil, the colloidal silica, the separating agent, the composition, and / or the emulsion, etc., of any element, process, additive, method step, composition, polymer, etc. as described in WO 2014 / 127083.Use of Silane Modified Colloidal Silica Without the Separating Agent

[0139] This disclosure also provides a method for at least partially separating a combination of oil and water comprising adding a silane modified colloidal silica to the combination of oil and water thereby effecting at least partial separation of the oil and the water. This can be done while expressly excluding the separating agent described herein or with thePCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PCseparating agent described herein. Moreover any one or more additives or other compounds described herein or known in the art may be included or excluded from such a method.

[0140] As described above, the silane modified colloidal silica includes colloidal silica particles in which the colloidal silica is modified with at least one organosilane moiety including a silicon atom bound to the carbon atom of an organic group particles. In other words, in various embodiments, at least a portion of surface silanol groups are replaced with one or more chemically bound organosilane groups.

[0141] The silane modified colloidal silica may be any described herein. Moreover, this method may be further described as including, or being free of, any element or step described herein relative to the other methods described. In other words, it is contemplated that the method for at least partially separating the combination of oil and water comprising adding the silane modified colloidal silica to the combination of oil and water may be the same as any other method described herein but for this method would not include the step of adding / utilizing the separating agent.

[0142] Typically, if the separating agent is not utilized, the silane modified colloidal silica may be utilized in an amount, relative to a total weight of the combination of oil and water, of from about 0.01 to about 30, about 0.01 to about 25, about 0.01 to about 20, about 0.01 to about 15, about 0.01 to about 10, about 0.01 to about 5, about 0.01 to about 1, about 0.01 to about 0.1, about 0.05 to about 30, about 0.05 to about 25, about 0.05 to about 20, about 0.05 to about 15, about 0.05 to about 10, about 0.05 to about 5, about 0.05 to about 1, about 0.05 to about 0.1, about 0.1 to about 30, about 0.1 to about 25, about 0.1 to about 20, about 0.1 to about 15, about 0.1 to about 10, about 0.1 to about 5, about 0.1 to about 1, about 1 to about 30, about 1 to about 25, about 1 to about 20, about 1 to about 15, about 1 to about 10, about 1 to about 5, about 5 to about 30, about 5 to about 25, about 5 to about 20, about 5 to about 15, about 5 to about 10, about 10 to about 30, about 10 to about 25, about 10 to about 20, about 10 to about 15, about 15 to about 30, about 15 to about 25, about 15 to about 20, about 20 to about 30, about 20 to about 25, or about 25 to about 30, weight percent actives based on one million parts by weight of the combination of oil and water. It is expressly contemplated that all values and ranges of values, both whole and fractional, including and between all of those set forth above, may be used herein in various non-limiting embodiments.PCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PC

[0143] For example, this disclosure provides a method for at least partially separating a combination of oil and water comprising adding colloidal silica to the combination of oil and water, thereby effecting at least partial separation of the oil and the water, wherein the colloidal silica is modified with at least one organosilane moiety comprising a silicon atom bound to the carbon atom of an organic group and wherein the method is free of the step of adding an additive to the oil and water. Such an additive may be any known in the art, e.g. any additive described in WO 2014 / 127083, or any described herein. In various embodiments, after addition of the colloidal silica, the combinations may be described as consisting essentially of the oil, the water, and the colloidal silica. In such embodiments, the terminology “consisting essentially of’ may described that the combination is free of, or includes less than 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0.5, 0.1, 0.05, or 0.01, weight percent of one or more of any additive, polymer, monomer, solvent, and / or alternative separating agent known in the art, based on a total weight of the combination.

[0144] It is contemplated that any part of this disclosure or any embodiment, e.g. method, combination, mixture, composition, compound, and / or emulsion, may include or be free of, or include less than 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0.5, 0.1, 0.05, or 0.01, weight percent, based on a total weight of the combination of water and oil, any colloidal silica, separating agent, composition, compound, combination, emulsion, element, additive, polymer, etc. as described in WO 2014 / 127083. Similarly, any embodiment may be free of, or include, any method, method step, process, technique, etc. as described in WO 2014 / 127083.Additional Embodiments

[0145] This disclosure also provides additional embodiments as described below. All combinations of the below, with one or more of each other and / or with any other embodiment described in this disclosure, are hereby expressly contemplated herein. All of the aforementioned embodiments and those set forth below are non-limiting embodiments.

[0146] In one embodiment, this disclosure provides a method wherein the organosilane moiety comprises an epoxy group or at least one hydroxyl group.

[0147] In another embodiment related to any method above, the method is conducted in an apparatus chosen from a free water knockout, a dissolved air flotation unit, a skim tank, a water clarifier, a sludge dewatering belt press, oilfield platforms, and combinations thereof.

[0148] In another embodiment related to any method above, the colloidal silica is present in the oil and water combination in an amount of from about 0.05 to about 20 weight percent activesPCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PCbased on one million parts by weight of the combination; and the separating agent is present in the oil and water combination in an amount of from about 0.2 ppm to about 50 weight percent actives based on one million parts by weight of the combination.

[0149] In another embodiment related to any method above, the method is utilized in an Enhanced Oil Recovery (EOR) process and / or Steam Assisted Gravity Drainage (SAGD) process.

[0150] This disclosure also provides an emulsion comprising:oil;water;colloidal silica; anda separating agent comprising a cellulose ether having the following structure (I):wherein each R1, R2and R3is independently H, a carboxymethyl group, a Cl -Cl 8 alkyl group, or a C2-C3 hydroxy alkyl group, so long as not all R1, R2and R3are H; and wherein n is from about 800 to about 10,000.

[0151] This disclosure also provides a method for at least partially separating a combination of oil and water comprising adding colloidal silica to the combination of oil and water, thereby effecting at least partial separation of the oil and the water, wherein the colloidal silica is modified with at least one organosilane moiety comprising a silicon atom bound to the carbon atom of an organic group and wherein the method is free of the step of adding an additive to the oil and water.EXAMPLES

[0152] A first series of emulsions is formed as shown below and evaluated to determine clarity both with and without various additives. After formation, clarity was measured using a line chart, as is appreciated in the art, wherein the finest line is placed on top because the oil separation startsPCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PCfrom the bottom and move upwards. The emulsion may have a clarity rating of from about 1 to about 10, wherein 1 is the best and 10 is the worst.

[0153] The Colloidal Silica 1 is a colloidal silica containing 2% solids (active) by weight. It is an organosilane modified colloidal silica having a surface area of 360 m2 / g and a particle diameter of 8 nm. The degree of modification was 1.4 molecules per nm2of silica surface, measured by Sear’s titration. The organosilane compound used to modify the silica was (3-glycidyloxypropyl)triethoxysilane.PCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PC

[0154] The Colloidal Silica 1 is dosed as a 2 wt% actives solution such that 2.5 ppm = 0.0000175 weight percent actives; 5ppm = 0.000035 weight percent actives; and lOppm = 0.00007 weight percent actives, when compared to the entire emulsion.

[0155] The Separating Agent 1 is a high molecular weight Methyl Ethyl Hydroxyethyl Cellulose, with number of glucose units of (approximately) 5000. DS Ethyi: 0.2-0.3 and DS Methyi: 0.6-0.8. (DS- degree of substitution: the average number of hydroxyl groups substituted with ether or methyl groups per repeating D-anhydroglucose unit.)

[0156] The Separating Agent 1 is dosed as a 0.5 wt% actives solution such that 2.5 ppm = 0.0000125 weight percent actives; 5ppm = 0.000025 weight percent actives; and lOppm = 0.00005 weight percent actives, when compared to the entire emulsion.

[0157] The results of the above evaluations are also set forth in FIGS. 1A and IB relative to 5ppm dosage and FIGS. 2A and 2B relative to lOppm dosage.

[0158] A second series of emulsions is formed as shown below and evaluated to determine clarity both with and without various additives. This series utilizes Colloidal Silica 2 and 3 which are different from colloidal silica 1 above.

[0159] The Separating Agent 1 is the same as above and dosed as described above.PCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PC

[0160] The Colloidal Silica 2 is an organosilane modified colloidal silica having a surface area of 220 m2 / g and a particle diameter of 12 nm. The degree of modification was 1.7 molecules per nm2of silica surface, measured by Sear’s titration. The organosilane compound used to modify the silica was (3-glycidyloxypropyl)triethoxysilane.

[0161] The Colloidal Silica 3 is aluminum modified colloidal silica containing 7% solids (active) by weight. The silica particles are structured, resulting in a S value below 30, and the particle surface is modified with aluminum. The surface area is 1100 m2 / g, as measured by Sears titration.

[0162] The Colloidal Silicas 2 and 3 are each individually dosed as a 2 and 7 wt% actives solution such that 2.5 ppm = 0.0000125 weight percent actives; 5ppm = 0.000025 weight percent actives; and lOppm = 0.00005 weight percent actives, when compared to the entire emulsion.

[0163] The results of the above evaluations are also set forth in FIG. 3.

[0164] A third series of emulsions is formed as shown below and evaluated to determine clarity without any additives. This series utilizes Colloidal Silicas 1, 2, and 4 without any Separating Agent.

[0165] The Colloidal Silica 1 is a colloidal silica containing 1% solids (active) by weight with the characteristics described for CS1 above. The silica particles are structured, resulting in a SPCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PCvalue below 30, and the particle surface is modified with aluminum. The surface area is 1100 m2 / g, as measured by Sears titration.

[0166] The Colloidal Silica 2 is a colloidal silica containing 1% solids (active) by weight with the characteristics described for CS2 above.

[0167] The Colloidal Silica 4 is a colloidal silica containing 1% solids (active) by weight. It is an organosilane modified colloidal silica having a surface area of 500 m2 / g and a particle diameter of 5 nm. The degree of modification was 1.7 molecules per nm2of silica surface, measured by Sear’s titration. The organosilane compound used to modify the silica was (3-glycidyloxypropyl)triethoxysilane.

[0168] Each of the Colloidal Silicas 1, 2, and 4 are dosed as a 1 wt% actives solution such that lOppm = 0.00007 weight percent actives, when compared to the entire emulsion.

[0169] The results of the above evaluations are also set forth in FIG. 4.Analysis of ResultsFast Separation Time:

[0170] The results show a quick separation after some minutes, this efficiency is important in oilfield operations where high throughput and quick turnaround times are necessary to maintain productivity. Quick separation ensures that the processes do not become a bottleneck, allowing for continuous and smooth operation of the oilfield. Furthermore, the separation is more comprehensive, yielding superior water quality in a significantly shorter time compared to conventional water clarifiers. This enhanced performance and rapid separation are particularly beneficial for offshore applications, where space and operational efficiency are critical. This is particularly seen when both colloidal silica and the separating agent are being used.Low Dosage Requirements:

[0171] Adding a few ppm of silica and the separating agent is enough to obtain a good separation, which makes it more cost-effective as it reduces the amount of chemical needed for effective treatment. This can result in significant cost savings over time. Lower dosage requirements reduces the costs, simplify the dosing process, reduces the complexity of handling and storing large quantities of chemicals.PCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PCEnvironmental Aspects (Biodegradability):

[0172] Both silica and the separating agents are environmentally friendly and non-toxic, making them safe for use in many applications. Their use helps in reducing the reliance on harsh chemicals, thereby contributing to more sustainable practices.

[0173] Biodegradable separating agents break down naturally in the environment, minimizing their ecological footprint. Many regions have strict environmental regulations governing the discharge of water. Using biodegradable separating agents helps ensure compliance with these regulations, avoiding potential fines and legal issues. It align with sustainability goals, promoting environmentally responsible practices in the oil and gas industry. Notably, the chemistry of this disclosure exhibits superior performance in high salinity brine conditions and moderate to high temperatures.

[0174] While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment. It being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope as set forth in the appended claims.

Claims

PCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PCCLAIMSWhat is claimed is:

1. A method for at least partially separating a combination of oil and water comprising:adding colloidal silica to the combination of oil and water; andadding a separating agent to the combination of oil and water simultaneously with, prior to, and / or subsequent to adding the colloidal silica to the combination of oil and water, thereby effecting at least partial separation of the oil and the water,wherein the separating agent comprises a cellulose ether having the following structure (I):wherein each R1, R2and R3is independently H, a carboxymethyl group, a Cl -Cl 8 alkyl group, or a C2-C3 hydroxy alkyl group, so long as not all R1, R2and R3are H; and wherein n is from about 800 to about 10,000.

2. The method of claim 1 wherein the cellulose ether is carboxymethyl cellulose.

3. The method of claim 1 wherein the cellulose ether is carboxymethyl cellulose sodium salt.

4. The method of claim 1 wherein each R1, R2and R3is independently H, a C1-C5 alkyl group, or a C8-C18 alkyl group or a C2-C3 hydroxy alkyl group, so long as not all R1, R2and R3are H.

5. The method of claim 1 wherein each R1, R2and R3is independently H, methyl, ethyl, a hydroxypropyl group, or a hydroxyethyl group, so long as not all R1, R2and R3are H.PCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PC6. The method of claim 1 wherein the cellulose ether is methyl cellulose.

7. The method of claim 1 wherein the cellulose ether is ethyl cellulose.

8. The method of claim 1 wherein the cellulose ether is hydroxypropyl cellulose.

9. The method of claim 1 wherein the cellulose ether is hydroxyethyl cellulose.

10. The method of claim 1 wherein the cellulose ether is hydroxypropyl methyl cellulose.

11. The method of claim 1 wherein the cellulose ether is hydroxyethyl methyl cellulose.

12. The method of claim 1 wherein the cellulose ether is ethyl hydroxyethyl cellulose.

13. The method of claim 1 wherein the cellulose ether is methyl ethyl hydroxyethyl cellulose.

14. The method of claim 1 wherein n is from about 3000 to about 10,000.

15. The method of any preceding claim wherein the colloidal silica has a surface area of from about 80 to about 1500 m2 / g.

16. The method of any preceding claim wherein the colloidal silica has an S-Value of less than about 75.

17. The method of any preceding claim wherein the colloidal silica is aluminum modified and has an AI2O3 content of from about 0.05 to about 3 wt%.PCT PATENT APPLICATIONATTORNEY DOCKET NO. 364.1917PC18. The method of any one of claims 1 to 16 wherein the colloidal silica is modified with at least one organosilane moiety comprising a silicon atom bound to the carbon atom of an organic group.

19. The method of claim 18 wherein the organosilane moiety comprises one or more groups Rmwhich is bound to the silicon atom of the organosilane, in which:each Rmis independently chosen from alkyl, alkenyl, epoxy alkyl, aryl, heteroaryl, Ci-6 alkylaryl and Ci-6 alkylheteroaryl groups, optionally substituted with one or more groups chosen from ERn, isocyanate and isocyanurate;E is either not present, or is a linking group chosen from -O-, -S-, OC(O)-, -C(O)-, -C(O)O-, -C(O)OC(O)-, -N(RP)-, -N(RP)C(O)-, -N(RP)C(O)N(RP)- and -C(O)N(RP)-, where Rpis H or Ci-6 alkyl;Rnis linked to E, or directly to Rmif E is not present;Rnis chosen from halogen (typically F, Cl or Br), alkyl, alkenyl, aryl, heteroaryl, C1-3 alkylaryl and C1-3 alkylheteroaryl, and each Rnis optionally substituted with one or more groups chosen from hydroxyl, halogen (typically F, Cl or Br), epoxy, -ORPor -N(RP)2;if E is present, Rnis optionally hydrogen, andwherein the alkyl groups are aliphatic or cyclic or comprise both aliphatic and cyclic portions, and the aliphatic groups are linear or branched.

20. The method of claim 18 wherein the organosilane moiety comprises at least one group chosen from hydroxyl, thiol, carboxyl, ester, epoxy, acyloxy, ketone, aldehyde, glycol ether, (meth)acryloxy, amino, amido, ureido, isocyanate, and isocyanurate groups.

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