RU2135527C1 - Method of preparing demulsifier to dehydrate and desalt water-oil emulsions - Google Patents

Abstract

FIELD: crude oil treatment. SUBSTANCE: invention is designed for treating high-viscosity stable tar oil stock emulsions with simultaneous protection of oil-field equipment. Two versions of demulsifier preparation are provided involving interaction of polyether with a functional groups-containing compound at heating. According to the first version, interaction of 1 mol of polyether with 1-2 mol of functional compound such as orthophosphoric acid, phosphoric anhydride, dimethyl phosphite, and p-toluenediisocyanate is followed by reaction of resulting intermediate product with 1 mol of carbohydrate. According to the second version, all reaction components interact simultaneously in the same proportions. Resultant demulsifier is then dissolved in organic solvent. EFFECT: improved dehydrating and desalting properties. 3 cl, 3 tbl, 5 ex

Description

 The invention relates to a method for producing a demulsifier, which can be used both when feeding into the collection system, and in oil treatment plants for deep dehydration and desalination of highly viscous, stable emulsions of tar oils, as well as for protecting oilfield equipment from corrosion.

 Known methods for producing demulsifiers for dehydration and desalting of oil by functionalizing polyethers with phosphorus-containing reagents - RU, 2008322 C1, 1994, p-toluene diisocyanate (TDIC), - RU 2089593, C1.1997.

 However, the demulsifiers obtained by these methods are not effective enough in the preparation of highly viscous stable emulsions of tarry oils.

 Closest to the invention is a method for producing a demulsifier by phosphorylation by heating polyethers followed by reaction with various amines - RU 2077786 C1, 1997.

 However, the demulsifiers obtained by this method are also not sufficiently effective in the preparation of highly viscous stable emulsions of tarry oils.

 The problem to which this invention is directed is the development of methods for obtaining a more effective demulsifier for dehydration and desalting of highly viscous persistent emulsions of tarry oils while protecting the equipment from corrosion.

 The problem is solved by the method of obtaining a demulsifier for dehydration and desalting of water-oil emulsions by the interaction of polyether and compounds with functional groups when heated. Moreover, the polyether and the compound with the functional groups selected are selected from orthophosphoric acid, phosphoric anhydride, dimethylphosphite, p-toluene diisocyanate, followed by the interaction of the obtained intermediate with a carbohydrate, the process is carried out at a molar ratio of polyether, compound with functional groups and carbohydrate 1: (1-2): 1 respectively.

 The problem is also solved by the method of obtaining a demulsifier for dehydration and desalting of water-oil emulsions by the interaction of polyether and compounds with functional groups when heated. In this embodiment of the method, compounds selected from orthophosphoric acid, phosphoric anhydride, dimethylphosphite and p-toluene diisocyanate are used as compounds with functional groups, and the process is carried out in the presence of a carbohydrate while the components are introduced at a molar ratio of polyether, compounds with functional groups and carbohydrate 1: (1-2): 1, respectively.

 In both process embodiments, the resulting demulsifier is further dissolved in an organic solvent.

As polyethers can be used:
1. Laprol - 6003-2B-18 - a simple polyester obtained by alcoholate polymerization of propylene oxide with glycerol, followed by block copolymerization with ethylene oxide (TU 6-05-221-880-86).

 2. Laprol - 4503 is a polyether obtained by alcoholate polymerization of propylene oxide with glycerin (TU 6-05-2033-87).

 3. Laprol - 3003 - a simple polyester obtained by alcoholate polymerization of propylene oxide with glycerol, followed by block copolymerization with ethylene oxide (TU 6-05-2947-87).

 4. Laprol - 5003-2-15 - polyether obtained by alcoholate polymerization of ethylene and propylene oxides with glycerin (TU 6-55-62-93).

 5. Laprol - 4202-2B-30 - a polyether obtained by alcoholate polymerization of ethylene and propylene oxides with ethylene glycol, which is the active base of Reapon-4V (TU 6-55-54-91).

 Orthophosphoric acid (GOST 6552-80), phosphoric anhydride (TU 6-09-4173-76), dimethyl phosphite (TU 6-00-5763445-11-89), p-toluene diisocyanate (TU 113-03- 17-17-85).

 The following carbohydrates are used: sucrose (GOST 22-94), potato starch (GOST 7699-78), corn starch (GOST 7697-82), dextrans (SIGMA reagents, mol. Mass 19600 - 40000000 cu), dextrins ( potato, wheat).

As solvents can be used:
1. Aromatic solvents: Nefras A 120/200 (TU 38.101.809-90), toluene (GOST 5789-78), ethylbenzene fraction TU 38.30225-81, butylbenzene fraction (TU 38.10297-76).

 2. Alcohols: methanol (GOST 2222-78), ethanol (TU 6-09-1710-77), iso-propanol (GOST 9805-84), bottoms of the production of standard butyl alcohols (TU 39-5794688-002-89) .

 3. A mixture of monoalkyl ethers of ethylene and diethylene glycol with alcohols.

As monoalkyl ethers of ethylene and diethylene glycols can be used:
ethylene glycol monoethyl ether (ethyl cellosolve) GOST 8113-88.

 diethylene glycol monoethyl ether (ethylcarbitol) TU 6-01-5757583-6-89.

 ethylene glycol monobutyl ether (butyl cellosolve) TU 6-01-646-84.

 diethylene glycol monobutyl ether (butylcarbitol) TU 8-05-10-50-86.

 4. A mixture of monoalkyl ethers of ethylene and diethylene glycol: alcohols: aromatic solvents.

 Example 1

In a round-bottom flask equipped with a stirrer and a thermometer, 50 g of Laprol 6003-2B-18 polyester, 1.65 g of phosphoric acid are charged and stirred for 4 hours at T = 130 ^° C. Then 1.4 g of potato starch is added and stirring is continued for another 2 hours at T = 130 ^o C. The molar ratio of reagents is 1: 2: 1, respectively.

 Example 2

In a round bottom flask equipped with a stirrer and a thermometer, 50 g of Laprol polyester - 4503, 1.6 g of phosphoric anhydride and 1.8 g of dextran are placed (mol. Mass = 19500). The reaction mixture was stirred for 3 hours at T = 130 ^° C. At the end of the reaction, the reaction mixture was decanted from the precipitate. The molar ratio of reagents is 1: 1: 1, respectively.

 Example 3

In a round-bottom flask equipped with a stirrer and a thermometer, 50 g of Laprol 4202-2B-30 poly ester, 2.5 g of dimethylphosphite are placed and the reaction mixture is heated for 2 hours at 130 ^° C. Then 1.8 g of dextrin are added and stirring is continued at the same temperature for another 2 h. The molar ratio of reagents is 1: 2: 1, respectively.

 Example 4

50 g of polyester grade L 6003-2B-18 are loaded into a round-bottom flask and vacuumized for 1 h at P = 15-20 mm Hg. Art. and T = 100 ^o C to remove residual moisture. Next, the temperature was lowered to 80 ^° C., 2.9 g of p-toluene diisocyanate was added and stirred for 1 h at atmospheric pressure. Then 1.4 g of corn starch is added, heated to 130 ^° C. and stirred for 3 hours at this temperature. At the end of the reaction, unreacted starch is filtered off. The molar ratio of reagents is 1: 2: 1, respectively.

 Example 5

1.6 g of dextran (mol. Mass = 267000), then 1.7 g of p-toluene diisocyanate are added to 50 g of vacuum-dried polyester grade L - 5003 - 2-15. The reaction mixture is heated to 100 ^o C and stirred at this temperature for 1 hour. The molar ratio of the reactants is 1: 1: 1, respectively.

 Example 6

2.8 g of dry dextrin and 2.9 g of p-toluene diisocyanate are added to 50 g of vacuum-dried L-3003 polyether. The reaction mixture is heated to 100 ^o C and stirred at this temperature for 3 hours. The molar ratio of reactants is 1: 1: 1, respectively:
The synthesis of the remaining samples presented in table. 1, carry out analogously to examples 1-6, varying the molar ratio of the starting reagents.

 The resulting products are viscous, colorless or yellowish oils.

 On their basis, commodity forms of a demulsifier are prepared by dissolving in a solvent.

 An example of the preparation of a demulsifier solution.

 To 50 g of the active base at room temperature add 50 g of the solvent of those mentioned in sections 1-3, and mix for 15 minutes.

 The obtained demulsifiers are tested for demulsifying and anticorrosive activity.

 Tests of demulsifying activity are carried out both on artificial and natural emulsions.

An artificial emulsion of 30% water cut is prepared on anhydrous coal-bearing oil of the Romashkinskoye field and formation water model. Anhydrous oil with a density of 0.868 g / cm ^{3 was} taken from the wellhead 14753. The mineralization of the reservoir water model used to prepare the emulsion is 200 g / dm ³ , and the density is 1.12 g / cm ³ .

As a natural emulsion, an emulsion of Devonian oil of bush 262 of the North-West field of NGDU "Mamontovneft" of OAO "Yuganskneftegaz" (density 0.86 g / cm ^3, viscosity 900 mm ² / s at 20 ^o C, resin content 15% by weight) is used.

 The reagents are dosed into the emulsion in the form of a 1% solution of the active base or 2% solution of the commodity form in a mixture of toluene and isopropanol, taken in a volume ratio of 3: 1.

 Testing.

The test demulsifier is dosed into the oil-water emulsion and shaken on a Wagner laboratory shaker for 30 minutes. at room temperature. Then thermostat at 40 ^o C for 2 hours and measure the amount of released water.

 The determination of the residual water content in oil is carried out in accordance with GOST 14870-77 by the Dean-Stark method.

The anticorrosive properties of the demulsifier obtained by the proposed methods are evaluated by the gravimetric method on a standard model of mineralization formation water - 190 g / dm ³ , density - 1.122 g / cm ³ , hydrogen sulfide content - 100 mg / dm ³ . Tests are carried out for 6 hours in hermetically closed circulation-type cells according to GOST 9-506-87. ("Inhibitors of metal corrosion in oil-water environments").

 The test results for demulsifying and anticorrosive activity of the samples are given in table. 12.

 For comparison, in table. 3 shows the data on the demulsifying effectiveness of the prototype (RF patent N 2077786) and analogues N 1 (RF patent N 2008322) and N 2 (patent N 2089593) at a flow rate of 40 g / t of oil and the proposed demulsifiers on examples NN 5, 92 at a flow rate of 40 g / t of oil tested in the oils of OAO Yuganskneftegaz.

 From the presented data it follows that the claimed method allows to obtain more effective demulsifiers for dehydration and desalination of highly viscous stable resinous emulsions and protect equipment from corrosion.

Claims (3)

 1. A method of obtaining a demulsifier for dehydration and desalting of water-oil emulsions by the interaction of a polyether and a compound with functional groups when heated, characterized in that the polyester and a compound with functional groups are first selected from orthophosphoric acid, phosphoric anhydride, dimethylphosphite, p-toluene diisocyanate , followed by the interaction of the obtained intermediate with a carbohydrate, and the process is carried out at a molar ratio of polyether, inenia with functional groups and carbohydrate 1: (1 - 2): 1 respectively.  2. A method of obtaining a demulsifier for dehydration and desalting of water-oil emulsions by the interaction of a polyether and a compound with functional groups when heated, characterized in that the compounds selected from orthophosphoric acid, phosphoric anhydride, dimethylphosphite, p-toluene diisocyanate are used as compounds with functional groups, a the process is carried out in the presence of a carbohydrate with the simultaneous introduction of components at a molar ratio of polyether, compounds with functional groups and carbohydrate 1: (1 - 2): 1, respectively.  3. The method according to claim 1 or 2, characterized in that the obtained demulsifier is dissolved in an organic solvent.

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