CA2936365A1 - Demulsifier for use in the oil and gas industry - Google Patents

Abstract

A demulsifier composition for use in the oil and gas industry, said composition comprising an admixture of an alkali and at least one alcohol.

Description

DEMULSIFIER FOR USE IN THE OIL AND GAS INDUSTRY
FIELD OF THE INVENTION
This invention relates to compositions for use as a demulsifier in performing various applications in the oil & gas industry, more specifically a de-emulsifier containing an alkali and an alcohol.
BACKGROUND OF THE INVENTION
1 0 The oil industry typically depends on demulsifiers (also referred to as emulsion breakers) during oil processing for the removal of water from crude oil. Prior to reaching the refinery, the water present in the oil must be removed or it can potentially lead to corrosion and equipment breakdown problems in the refinery.
The water present in the crude oil is typically resent as a result of the saline water being used in the oil extraction processes. Preferably both the water and the salt must be removed to minimize the occurrence of problems during the refining process.
The Athabasca deposits in Western Canada are the largest oil sands found in the world containing around 168 billion barrels reserves of crude oil, the third largest reserves in the world. In 2014, the oil sands production in Alberta reached to 2.3 million barrels per day. The in-situ recovery processes such as Cyclic Steam Stimulation (CSS) and Steam Assisted Gravity Drainage (SAGD) are most common thermal recovery technologies to recover bitumen and heavy oil. For instance, the SAGD
operations require two parallel horizontal wells: a top well for steam injection and a bottom well for water and bitumen production. Steam is injected continuously into the top well, creating a steam chamber that grows as the steam condenses on the chamber walls and ceiling and releases heat. Meanwhile, heated bitumen and condensed steam drain by gravity into the lower production well and then are pumped out.
Water-in-oil emulsions are produced in the field due to shear forces applied in oil and water streams and are evident in various processes such as CHOPS, SAGD, or CCS. The emulsions are normally stabilized by natural chemicals such as asphaltcncs and resins, or solid particles.
Emulsions may be broken by four mechanisms: sedimentation, creaming, aggregation, and coalescence. In order to break W/O emulsions, demulsifiers need to be used.

Numerous and various types of demulsifiers have been patented and the following is but a short list of demulsifiers relevant to the oil and gas industry.
US Patent No. 2,602,056 teaches a process for breaking petroleum emulsions of the water-in-oil type characterized by subjecting the emulsion to the action of a demulsifier including hydrophile synthetic products; said hydrophile synthetic products a divalent radical of an unsaturated dicarboxy acid selected from the class consisting of maleic acid, fumaric acid, and citraconic acid, and n is a whole number varying from 12 to 80; R is a hydrocarbon radical having less than 8 carbon atoms; and with the further proviso that the corresponding polypropylene glycol ether of the formula RO(C3H50)H be water-insoluble and kerosene-soluble.
US Patent No. 2,882,224 A teaches the treatment of hydrocarbon distillates and more particularly to a novel method of gaseous fractions. It is stated that according to another embodiment the novel features of the present invention may be utilized for purifying other organic fractions containing certain acidic impurities. These organic compounds include alcohols, ketones, aldehydes, etc.
It is stated that in one embodiment the present invention relates to a process for sweetening a sour hydrocarbon distillate which comprises reacting said distillate with an oxidizing agent in the presence of a phthalocyanine catalyst.
US Patent No. 3,383,325 teaches a process for breaking petroleum emulsions of the water-in-oil type which comprises subjecting said emulsion to the demulsifying action of a substantially waterinsoluble, at least partially oil-soluble product formed by the reaction of (A) a polyoxyalkylene alcohol in which the oxyalkylene groups consist essentially of a member from the group consisting of oxypropylene, oxybutylene, and both oxypropylene and oxybutylene, with at least one terminal Z-hydroxyethyl group and (B) a diglycidyl other of a bis-phenol compound having an epoxide equivalent in the range of 145 to less than 250 in which about 60% to 90% of said diglycidyl ether groups.
US Patent Application No. 2015/0210938 teaches an aqueous water clarifier composition further coinprises an alcohol ii). Suitable alcohols may be selected from the group consisting of glycols, glycol ethers, methanol, ethanol and combinations thereof. Preferably, the alcohol is selected from isopropanol, diethyleneglycol monobutyl ether, ethyleneglycol monobutyl ether, diethylene glycol monoethyl ether, ethyleneglycol monobutylether, ethyleneglycol monopropylether, dipropyleneglycol monomethyl ether, dipropyleneglycol monobutyl ether, propylene glycol monomethyl ether, propyleneglycol monopropyl ether, propyleneglycol monobutyl ether, butyl acetate, propylene glycol, ethylene glycol, and combinations thereof, preferably propylene glycol, more preferably ethylene glycol. It is stated that among the suitable bases are

2 strong bases such as potassium hydroxide. It also lists as suitable OH-containing solvents are methanol, ethanol, isopropanol, n-butanol.
US Patent Application No. 20040244278 Al teaches a fuel oil comprising a major proportion of a mixture of A) a middle distillate fuel oil, and B) a biofuel oil, and also a minor proportion of C) an oil-soluble copolymer of ethylene and at least 0.2 to 35 mol `A of a further olefinically unsaturated compound which contains at least one free hydroxyl group, and which has an OH number of from 10 to 300 mg KOH/g.
US Patent Application No. US 20140135515 Al teaches methods for recovering free fatty acids from fats and oils having high free fatty acid content. It is stated that in the method, fats and oils are treated with a mixture having an alcohol to result in a low-free fatty acid oily phase and an alcohol phase. It is also mentioned that the mixture may also include an alkali. The alcohol may be a monohydric alcohol and an aqueous alcohol, such as an aqueous alcohol having a concentration of at least about 15% alcohol by weight.
The alcohol phase may be treated with an acid to form an aqueous alcohol phase and a lipid alcohol phase, wherein the lipid alcohol phase includes free fatty acids, which may be recovered. Fats and oils amenable to such a method may include, but are not limited to, waste fats, waste oils, high acid grease, high acid tallow, and corn oil, such as corn oil produced at an ethanol production plant. It is stated that the monohydric alcohols used in the method may include methanol, aqueous methanol, ethanol, aqueous ethanol, propanol, aqueous propanol, isopropanol, aqueous isopropanol, butanol, aqueous butanol, isobutanol, aqueous isobutanol, pentanol, aqueous pentanol, and combinations thereof. It is also stated that the alcohol may be an aqueous ethanol including about 15-55% ethanol by weight and that the treatment of fats and oils with a mixture comprising a monohydric alcohol and an alkali may occur at about 25 to 75 degrees Celsius, such as at 65 degrees Celsius, and at about atmospheric pressure.
US Patent Application No. US 20080153931 Al teaches the use of nondendrimeric, highly functional, hyperbranched polymers as demulsifiers for breaking crude oil emulsions. The hyperbranched polymers are preferably hyperbranched polycarbonates, hyperbranched polyesters, hyperbranched polyethers, hyperbranched polyurethanes, hyperbranched poly ureapolyurethanes, hyperbranched polyureas, hyperbranched polyamides, hyperbranched polyetheramines and hyperbranched polyesteramides which are functional groups selected from the group consisting of ¨0C(0)0R, ¨COOH, ¨COOR, ¨CONHR, ¨
CONH2, ¨OH, ¨SH, ¨NH2, ¨NHR, ¨NR2, ¨S03H, ¨SO3R, ¨NI-ICOOR, ¨NHCONH2 and ¨
NHCONHR, where R is an optionally substituted alkyl or aryl radical.
US Patent No. 5,977,287 A teaches a composition comprising tannin containing hydroxyl groups

3 which has been (a) chemically modified by reaction of at least one of said hydroxyl groups with at least one member selected from the group consisting of an esterification agent (e.g.
acetic anhydride), etherification agent (e.g. dichloromethane or quaternary organic amine such as N-(3-chloro-2-hydroxypropyl) trimethyl ammonium chloride) to form the corresponding ester, or ether, through said hydroxyl group, and (b) derivatized. The chemically modified tannin is derivatized by reaction with aldehyhde (e.g. formaldehyde), or aldehyde and at least one member selected from the group consisting of ammonia and organic amine containing at least one primary or secondary nitrogen (e.g. cyclohexyl amine);
said derivatized tannin being water soluble or dispersable at a pH below 7 and water insoluble at a pH above 7. The chemically modified tannins are useful for the coagulation and/or detackification of solid particles suspended in the aqueous system, such as paint particles suspended in the waste water of a paint spray booth operation. Such tannins also have utility for demulsifying oil-in-water emulsions.
US Patent Application No. US 20150225324 Al teaches methods for removing one Or more components from a butanol based composition. The methods comprise providing a butanol based composition comprising one or more components, targeting at least one component or a combination thereof for reduction, and processing said butanol based composition such that the at least one targeted component is substantially removed. The butanol based composition can, for example, be bio-produced.
US Patent No. 4,439,345 teaches a process for the demulsification of a middle phase emulsion of a crude oil emulsion produ.ced by a surfactant flood comprising contacting the middle phase emulsion with a water-soluble alkali metal hydroxide selected from the group consisting of sodium hydroxide and potassium hydroxide in an amount sufficient to cause demulsification of the emulsion.
Previous research by Sjoblom et al. (SjOblom, J.; Stiderlund, H.; Lindblad, S.; Johansen, E. J.;
Skjarvo, 1. M., Water-in-crude oil emulsions front the Norwegian continental shelf Part 1! Chemical destabilization and interfacial tensions. Colloid and Polymer Science 1990, 268 (4), 389-398) reported that medium chain alcohols Eke 1-butanol and benzyl alcohol and amines would speed up the separation of water/crude oil emulsions. The alcohols seemed to modify the rigidity of the interfacial film by a diffusion/partitioning process. In particular, a branching of the alcohol did not accomplish an enhanced ability to destabilize the emulsions. Moreover, pH was found to influence the stability of the emulsions in such a way that intermediate pHs gave rise to some instability while extremely low or high pHs rendered restored or even enhanced stability.

4 A review by Ekott and Akpabio (Ekott, E. J.; Akpabio, E. J., A Review of Water-in-Crude Oil Emulsion Stability, Destabilization and Interfacial Rheology. Journal of Engineering and Applied Sciences 2012) concluded that the complexity of petroleum emulsions comes from the oil composition in terms of surface-active molecules contained in the crude such as resin and asphaltenes.
Most recently, Kelland (Kelland, M. A.; ebrary Inc., Production chemicals for the oil and gas industry. Second edition. ed.; 2014; p.
1 online resource) reported that water-soluble demulsifier components can be made oil soluble by adding a coupling solvent such as an alcohol or glycol. Methanol is often used in cold climate applications to avoid unacceptably high viscosity.
Despite the quantity of known and available demulsifiers, there still exists a need for a novel demulsifying composition which has a broad range of applications in the oil and gas industry which provides a faster, cleaner and better separation of water from oil at the lowest possible cost per unit barrel of oil.
SUMMARY OF THE INVENTION
According to a first object of the present invention, there is provided a demulsifier comprising an admixture of an alkali and at least one alcohol.
According to a second object of the present invention, there is provided a demulsifier composition concentrate comprising an admixture of an alkaline solution; and an alcoholic solution, where in the alkaline solution and alcoholic solution are mixed at a temperature not exceeding 25 C.
Preferably, the alkali is selected from the group consisting of: potassium hydroxide; sodium hydroxide and a combination thereof.
According to another object of the present invention, there is provided a demulsifier composition, said composition comprising:
- an admixture of an alkali; a solvent for the alkali; and at least one alcohol.
Preferably, the content of the alkali ranges from about 1 to about 10% by weight of the composition.
More preferably, the content of the alkali ranges from about 2 to about 5% by weight of the composition.

5 According to a preferred embodiment of the present invention, the content of the at least one alcohol ranges from about 80 to about 99% by weight of the composition. Preferably, the content of the at least one alcohol ranges from about 92 to about 97% by weight of the composition.
According to a preferred embodiment of the present invention, the solvent for the alkali is selected from the group consisting of: methanol, ethanol, propanol, isopropanol, water and combinations thereof.
Preferably, the solvent fox the alkali is ethanol. According to another preferred embodiment, the solvent for the alkali is water. Preferably, the content of the solvent for the alkali ranges from about 1 to about 10% by weight of the composition.
According to a preferred embodiment of the present invention, the at least one alcohol is selected from the group consisting of: isopropanol; 1-butanol; isobutanol; and combinations thereof. Preferably, the at least one alcohol is isobutanol. Preferably, the at least one alcohol is 1-butanol.
According to another object of the present invention, there is provided a method to remove an emulsion from extracted bitumen, wherein said method comprising:
- adding to a reservoir containing an oil/water emulsion a fluid composition comprising:
- an alkali; a solvent for the alkali; and at least one alcohol; and - mixing and/or agitating the composition within the reservoir; and - allowing a sufficient period of time to elapse to allow for a separation of the oil phase from the water phase;
- removing the water phase and suspended solids from the reservoir.
Preferably, the alkali is selected from the group consisting of; potassium hydroxide; sodium hydroxide and a combination thereof. Preferably also, the alkali ranges from about 1 to about 10% by weight of the composition. More preferably, the content of the alkali ranges from about 2 to about 5% by weight of the composition.
According to a preferred embodiment, the content of the at least one alcohol ranges from about SO to about 99% by weight of the composition. More preferably, the content of the at least one alcohol ranges from about 92 to about 97% by weight of the composition.
According to a preferred embodiment, the solvent for the alkali is selected from the group consisting of: methanol; ethanol; propanol; isopropanol; water and combinations thereof.
According to a preferred

6 embodiment, the solvent for the alkali is ethanol. According to another preferred embodiment, the solvent for the alkali is water. Preferably, the content of the solvent for the alkali ranges from about 1 to about 10%
by weight of the composition.
According to a preferred embodiment, the at least one alcohol is selected from the group consisting of: isopropanol; butanok isobutanol; and combinations thereof. According to a preferred embodiment,the at least one alcohol is isobutanol. According to another preferred embodiment, the at least one alcohol is isopropanol.
According to another object of the present invention, there is provided a method of preparing a demulsifier composition comprising an alkali, an solvent for the alkali and at least one alcohol, wherein the alkali and the solvent for the alkali are mixed together creating a mixture and the at least one alcohol is added to the mixture; wherein all the components are mixed at a temperature not exceeding 25 C. Preferably, the alkali and at least one alcohol comprise more than 85% of the total weight of the demulsifier. More preferably, the alkali and at least one alcohol comprise more than 90% of the total weight of the demulsifier.
Even more preferably, the alkali and at least one alcohol comprise more than 92% of the total weight of the demulsifier. Yet even more preferably, the alkali and at least one alcohol comprise more than 95% of the total weight of the demulsifier.
BRIEF DESCRIPTION OF THE FIGURES
The invention may be more completely understood in consideration of the following description of various embodiments of the invention in connection with the accompanying figure, in which:
Figure 1 is a typical curve of separation efficiency versus dosage of additives at various concentrations of sodium hydroxide;
Figure 2 is a graph showing the relation between IFT and pH of aqueous phase;
and Figure 3 shows a particle size distribution of the water droplets found in the emulsion.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE PRESENT
INVENTION
The particular values and compositions discussed in these non-limiting examples can be varied and are cited merely to illustrate at least one embodiment and are not intended to limit the scope thereof.

7 =

Initially one of the objectives was to achieve a desired number of solvent emulsions for breaking of water-in-heavy oil emulsions from Tamarack Valley Energy. Subsequently, screening for the additives with best performance on emulsions breaking was initiated. Afterwards, the optimization of demulsifiers formulation for separation of water from W/O heavy oil emulsions was carried out. Then, phase behavior and oil properties during emulsions breaking process were investigated.
All chemicals in the present study were of ACS grade. The various solvents tested for emulsion breaking included: 1-butanol; isobutanol; isopropyl alcohol; hexane; hexane;
paraffin oil. Low concentrations of solubilised potassium hydroxide were added to those solvents. In a preferred embodiment, anionic and non-ionic surfactants, i.e. sodium dodecyl sulfate, might be selected to improve the efficiency of emulsions breaking or water separation.
Preparation of the Emulsions Tested Initially, the original emulsions from Tamarack Valley Energy were used directly in testing. In the second step, the heavy oil emulsions would be prepared according to the properties of emulsion, such as water content, density, viscosity, temperature, and size of droplets, and so on.
Emulsions Breaking Testing Using a Centrifuge After separating the free water, the original Tamarack W/O emulsions were used in the tests. 50 mL
of an emulsion were transferred into a 125 mL Nalgene bottle. The demulsified solvents were added to emulsions with specific ratios. The testing bottles were placed in an oven at 60 C for 30 min. The mixtures were mixed and then put in the centrifuge at 5,000 rpm for 30 minutes. Samples were taken from the top of bottle. Microscopy images were taken and water contents were measured by Karl Fischer Titration. If necessary, testing of density and viscosity was conducted.
Bottle Testing for Determination of the Effects of Solvent Additives Preparation of W/O emulsion samples with original W/O and aqueous phase fluid.
50 int, emulsions were transferred into 125 mL Nalgene* bottle. Demulsifier solvents are added to emulsions with specific ratios. The testing bottles were placed in an oven at 60 C for 30 min. The mixtures were mixed and then put in the centrifuge at 5,000 rpm for 30 minutes. A sample was taken from the top of bottle. Microscopy images were taken and water contents were measured by Karl Fischer Titration.
Where necessary, density and viscosity testing was conducted.

8 Demulsifier Selection Criteria To screen demulsifiers, the most common method is conducted by the bottle test. In general, the testing would be carried out for demulsifiers at various operating parameters, such as concentrations, temperatures, and water contents. After the bottle tests, a few more promising demulsifiers were selected for pilot testing. The best demulsifier is the one that produces the fastest, cleanest separation at lowest possible cost per unit barrel of crude. For instance, the demulsifier concentrations generally range from less than 5 ppm to more than 200 ppm, and the optimal range is between 10 and 50 ppm.
Properties of the Water Phase and Emulsions The pH of water phase is 8.3 and the salinity of water phase is around 8000 ppm NaCI. The water contents of Tamarack emulsions ranged from 15% to 30%. More details can be seen in Table 1.
In a series of tests when added to oil/water emulsions, the demulsifying composition according to a preferred embodiment of the present invention, provided the following results.
Table 1 - Properties of Original Tamarack Valley Emulsions.
Name Density (g/cm3) Viscosity Asphltenes =
Water cut TAN (mg at 15.56 C (mPa.$) at (vvt%) (wt%) KOH/g) C
Original 0.9895 9228 7.4 15 to 30 0.257 emulsion Density (g/cm3) PH Salinity (ppm at 25 C NaC1) Aqueous phase 0.997 8.3 8,000 Selection of Solvent Demulsifiers ¨ 1" Phase 20 The emulsions were mixed with solvents at various concentrations and the microscopy images were taken after testing 4 hours. The results indicated that both 0.25 M KOH/IPA
and 0.25 M KOH/isobutanol, at 5%, 10%, and 15%, had excellent performance on emulsions breaking. It was noted that the emulsions couldn't be broken under mixing with isobutanol only.

9 Selection of Solvent Demulsifiers - 2"d Phase Further tests were conducted to explore optimal KOH concentrations and demulsifiers usage. The tests showed that 0.05 M KOH in solvents already had a substantial influence on emulsion breaking and water separation. However, 0.50 M KOH/isobutanol showed better performance than low KOH
concentrations such as 0.05 M and 0.10 M KOH/isobutanol. The results from this phase are summarized in Table 2.
Table 2 - Experimental Results for Emulsions Breaking with Various Demulsified Solvents Additives ID = Oil extracted (g) Concentrations 5% 10% 15% 20%
0.05M KOH/isobutanol 0.8956 0.9475 0.10M KOH/isobutanol 0.8566 0.9680 0.20M KOH/isobutanol 0.90'70 1.7436 0.25M KOH/isobutanol 0.5515 1.8759 3.0971 0.40M KOH/isobutanol 1.4495 2.2369 3.410 0.50M KOH/isobutanol 1.5967 2.5369 3.8134 Selection of Solvent Demulsifiers - 3rd Phase First, the emulsions were mixed with 5% of demutsified solvents as shown in Table 3, and settled down for about 30 minutes. Then the mixtures were put in a centrifuge at

10,000 rpm for two hours. The top samples were extracted immediately for water content measurement by Karl-Fischer Titration. At the same time, microscopy images were taken as well. The water contents of extracted oils, as shown in Tables 3 and 4, suggest that solvents of 0.5 M KOH/isobutanol, varsol mixture, and paraffin mixture have better performances compared to other solvents.
Table 3 - Water contents of extracted oil after emulsion breaking and centrifuging (Test A) Sample ID Water cut (wt%) Density (g/cm3) Viscosity (mPit-s) at 15.56 C at 25 C
Original Tamarack 25.55 0.9824 9139.73 emulsions 0.5 M KOH/isobutanol 8.78 0.9800 3091.49 0.5 M KOH/IPA 17.44 lsobutanol 13.33 1-butanol 15.20 IPA 23.19 Paraffin mixture 7.55 0.9771 3083.55 Varsol Mixture 7.60 0.9'721 1771.68 =
Table 4 - Water contents of extracted oil after emulsion breaking and centrifuging using 5%
solvents (Test B) Sample ID Water cut (wt%) Original Tamarack 19.06 emulsions 1% KOH/1-butanol 5.1 1% K01-1/isobutanol 2.8 1% KOH/varsol tn ix 13.08 1% KOH/paraffin mix 18.39 1-butanol 15.91 These results show that KOH/isobutanok KOH/1-butanol, varsol mixture have shown the best performance on emulsion breaking. Additional testing have suggested that emulsions couldn't be broken under only with isobutanol. The primary test shows 1-butanol had no significant benefit over isobutanol on emulsions breaking. The testing results also indicated that an alkali such as potassium hydroxide could boost the emulsion breaking.
Additional testing was carried out using preferred compositions to further study the emulsion breaking capacity of each one. Table 5 summarizes the results from those tests.
Table 5 - Water Contents of Extracted Oil After Emulsion Breaking and Centrifuging for Various Mixture of Solvent/KOH
Sample ID Water cut Separation efficiency (%) (wt%) Original w/O emulsions 25.55 0.5 M KOH/isobutanol 8.78 65.6 0.5 M KOH/1PA 17.44 31.7 1% KOH/1-butanol 5.1 80.0 1% KOH/isobutanol 2.8 89.0 1% KOH/varsol mix 13.08 48.8 1% KOH/paraffin mix 18.39 28.0 Additional testing was carried out using compositions comprising 1-butanol and isobutanol as well as varsol and ethanol and varying the concentration of alkali (in this case NaOH was used) to further study the emulsion breaking capacity of each composition. Table 6 summarizes the results from those tests.

11 Table 6 - Water Contents of Oil Emulsion After Emulsion Breaking of 5%
Additives _ Sample ID Water cut (wt%) Separation efficiency CYO
Original Tamarack emulsions 24.75 0.5% Na0H/1-butanol 6.15 75.2 1.0% Na0H/1-butanol 4.87 80.3 1.5% Na0H/1-butanol 4.65 81.2 0.5% Na0H/isobutanol 8.33 _ 66.3 1.0% Na0Hfisobutanol 2.46 90.1 1.5% Na0H/isobutanol 2.71 89.1 1.0% Na0H/varsol mixture 17.38 29.8 1% NaOH/ethanol 22.13 10.6 5% NaOH/ethanol 21 15.2 The dosage of additives for demulsification of W/O petroleum emulsions depends on a number of factors, such as properties of crude oil, brines, temperatures, and assistance of surfactant & polymer. Some of the present research has shown that the minimum dosage of additives is 5%, for W/O petroleum emulsions.
Figure 1 shows a typical curve of separation efficiency versus dosage of additives at various concentrations of sodium hydroxide. The separation efficiency can reach more than 90% at 5% of additive dosage. On the contrary, the separation efficiencies of emulsion breaking are only around 30% when a 4%
amount of additives is used.
Furthermore, numbers of tests were conducted to determine the optimal KOH
concentrations for assistance of emulsion breaking. The results suggest that an alkali, such as potassium hydroxide, with the solvents tested provided a substantial benefit on emulsion breaking and water separation. The concentration of 1% KOH showed excellent performance for demulsification with isobutanol or 1-butanol compared to other lower or higher KOH concentrations. Moreover, experimental data (Tables 7 and 8) indicated that NaOH has a similar impact on the promotion of emulsion breaking.
Table 7 - Water contents of extracted oil after emulsion breaking and centrifuging for various mixture of solvent/KOH
Sample ID Water cut (wt%) Separation efficiency (%) Original W/O emulsions 25.55 0.5 M KOH/isobutano I 8.78 65.6 0.5 M KOH/IPA 17.44 31.7 1% KOH/l-butanol 5.1 80.0 1% KOH/isobutanol 2.8 89.0

12 1% KOH/varsol mix 13.08 48.8 1% KOH/paraffin mix 18.39 28.0 = Table 8- Water contents of oil emulsion after emulsion breaking cif 5% additives Sample I.13 Water cut (wt%) Separation efficiency (%) Original Tamarack emulsions 24.75 0.5% Na01-1/1-butanol 6.15 75.2 1.0% Na0H/1-butanot 4.87 80.3 1.5% Na0H/1-butano I 4.65 81.2 0.5% Na0H/isobutanol 8.33 66.3 1.0% Na0H/isobutanol 2.46 90.1 1.5% Na0H/isobutano I 2.71 89.1 1.0% Na01-1/varsol mixture 17.38 29.8 1% NaOH/ethanol 22.13 10.6 5% NaOH/ethanol 21 15.2 Figure 2 displays the relation between IFT and pH of aqueous phase. IFT has lowest level at pH
value of 10 but reaches somewhat of a plateau starting at pH 9.
Figure 3 shows a particle size distribution of the water droplets found in the emulsion. The arithmetic mean of aqueous droplets is 1.74 um and the droplets mostly are ranged from 0.25 um to 6.25 um.
Table 9 summarizes the findings with respect to particle size.
Table 9 - Properties of water drops in 1V/0 petroleum emulsions _ Image size (mm2) 1377141.3 _Arith. mean (mm) 1.74 water drops 192234.2 Geo. mean (mm) 1.30 (mm2) Emulsion fraction 27.9179 Median (mm) 1.13 (%) Mode (mm) 0.2 l Std Dev (mm) 1.36 Droplet' size (mm) Incr. (frac) Cum (frac) 0.25 0.05 0.05 0.5 , 0.12 0.17 0.75 0.14 0.31 1 0.13 0.43 1.25 0.11 0.54 1.5 0.08 0.62 1.75 0.07 0.69 2 0.05 0.74 2.25 0.04 0.78 2.5 0.03 0.81 5 , 0.15 0.96 10 0.03 1.00 0.00 1,00 >15 0.00 1.00

13 =

=
Iso-butanol and 1-butanol gave similar results, while lower alcohols failed.
KOH and NaOH were tested. According to a preferred embodiment of the present invention, the composition may also comprise tri-methyl-amine and/or pyridine. According to a preferred embodiment of the present invention, the composition may also comprise glycerol-NaOH as an alternative embodiment.
Additionally, according to another preferred embodiment of the present invention, surfactants may be added in the composition. More preferably, the surfactants would be selected from the group consisting of:
Span 6 60 and sodium dodecyl sulfate.
Study of the influence of emulsion breakinz on viscosity The experimental results summarized in Table 10, show that high water content of water-in-oil contributes to the viscosity of emulsions. This viscosity effect is related to the greater forces of interaction between the water and the polar of the oil.
Table 10 - Experimental .results of density & viscosity for emulsion breaking Water Cut Density @ Viscosity @ 25oC
(wt%) 15.56oC (g/cm3) (mPa.$) Original Emulsions 25.06 0.9896 9284 1% KOH/l-butanol (5%) 5.1 0.9763 2109 1% KOH/isobutanol (5%) 2.8 0.9758 2322 1% KOH/Paraffin Mixture (5%) 18.39 0.9812 4734 Study of the Influence of Salinity on Separation Efficiency A preliminary study of the influence of salinity on demulsification was carried. Some tests suggest that high salinity is beneficial for emulsion breaking.
Table 11 - Experimental results for influence of salinity of aqueous phase Separation Efficiency Salinity (NaC1) 0.80% 5.60%
1.0% Na0H/isobutanol, 5% 93.0 96.3 1.5% NaOH/isobutano1,5% 90.4 95.9 2.0% Na0Wisobutanol, 5% 69.4 95.5

14 It will be appreciated that variations of the above disclosed and other features and functions, or alternatives thereof, maybe desirably combined into many other different compositions or for other applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein maybe subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.
=

Claims (33)

1. A composition for use as demulsifier comprising an admixture of an alkali and at least one alcohol.

2. A demulsifier composition concentrate comprising an admixture of an alkaline solution; and an alcoholic solution, where in the alkaline solution and alcoholic solution are mixed at a temperature not exceeding 25°C.

3. The composition according to claim 1 or 2 where the alkali is selected from the group consisting of:
potassium hydroxide; sodium hydroxide and a combination thereof.

4. A demulsifier composition, said composition comprising:
- an admixture of an alkali; a solvent for the alkali; and at least one alcohol.

5. The composition according to any one of claim 1 to 4 wherein the content of the alkali ranges from about 1 to about 10% by weight of the composition.

6. The composition according to claim 5 wherein the content of the alkali ranges from about 2 to about 5% by weight of the composition.

7. The composition according to any one of claims 1 to 6, wherein the content of the at least one alcohol ranges from about 80 to about 99% by weight of the composition.

8. The composition according to claim 7, wherein the content of the at least one alcohol ranges from about 92 to about 97% by weight of the composition.

9. The composition according to claim 4 to 8, where the solvent for the alkali is selected from the group consisting of- methanol, ethanol, propanol, isopropanol, water and combinations thereof.

10. The composition according to claim 9, where the solvent for the alkali is ethanol.

11. The composition according to claim 9, where the solvent for the alkali is water.

12. The composition according to claim 9 wherein the content of the solvent for the alkali ranges from about 1 to about 10% by weight of the composition.

13. The composition according to any one of claims 1 to 12, wherein the at least one alcohol is selected from the group consisting of: isopropanol; 1-butanol; isobutanol; and combinations thereof.

14. The composition according to claim 13, wherein the at least one alcohol is isobutanol.

15. The composition according to claim 13, wherein the at least one alcohol is 1-butanol.

16. Method to remove an emulsion from extracted bitumen, wherein said method comprising:
- adding to a reservoir containing an oil/water emulsion a fluid composition comprising:
- an alkali; a solvent for the alkali; and at least one alcohol; and - mixing and/or agitating the composition within the reservoir; and - allowing a sufficient period of time to elapse to allow for a separation of the oil phase from the water phase;
- removing the water phase and suspended solids from the reservoir.

17. The method according to claim 16 wherein the alkali is selected from the group consisting of:
potassium hydroxide; sodium hydroxide and a combination thereof.

18. The method according to claim 15 or 16 wherein the content of the alkali ranges from about 1 to about 10% by weight of the composition.

19. The method according to any one of claims 16 to 18 wherein the content of the alkali ranges from about 2 to about 5% by weight of the composition.

20. The method according to any one of claims 16 to 19, wherein the content of the at least one alcohol ranges from about 80 to about 99% by weight of the composition.

21. The method according to any one of claims 16 to 20, wherein the content of the at least one alcohol ranges from about 92 to about 97% by weight of the composition.

22. The method according to any one of claims 16 to 21, where the solvent for the alkali is selected from the group consisting of: methanol; ethanol; propanol; isopropanol; water and combinations thereof.

23. The method according to claim 22, where the solvent for the alkali is ethanol.

24. The method according to claim 23, where the solvent for the alkali is water.

25. The method according to claim 22 wherein the content of the solvent for the alkali ranges from about 1 to about 10% by weight of the composition.

26. The method according to any one of claims 16 to 25, wherein the at least one alcohol is selected from the group consisting of: isopropanol; butanol; isobutanol; and combinations thereof.

27. The method according to claim 26, wherein the at least one alcohol is isobutanol.

28. The method according to claim 26, wherein the at least one alcohol is isopropanol.

29. Method of preparing a demulsifier composition comprising an alkali, an solvent for the alkali and at least one alcohol, wherein the alkali and the solvent for the alkali are mixed together creating a mixture and the at least one alcohol is added to the mixture; wherein all the components are mixed at a temperature not exceeding 25°C.

30. Method according to claim 29, wherein the alkali and at least one alcohol comprise more than 85%
of the total weight of the demulsifier.

31. Method according to claim 29, wherein the alkali and at least one alcohol comprise more than 90%
of the total weight of the demulsifier.

32. Method according to claim 29, wherein the alkali and at least one alcohol comprise more than 92%
of the total weight of the demulsifier.

33. Method according to claim 29, wherein the alkali and at least one alcohol comprise more than 95%
of the total weight of the demulsifier.