SU1609980A1 - Microemulsion for displacing oil - Google Patents

Abstract

The invention relates to the oil industry. The goal is to increase the efficiency of oil displacement from the formation containing asphalt-resin-paraffin substances. The microemulsion contains the following components with their ratio, vol.%: 4,4-dimethyl-1,3-dioxane fraction 25-40

ethoxylated alkylphenol AF-12 8-13

isopropyl alcohol 2,6-5,0

1% aqueous solution of sodium chloride the rest. A microemulsion is prepared by mixing the components in any order. The microemulsion makes it possible to increase the oil displacement coefficient 1.1-1.34 times. 2 tab.

Description

The invention relates to the oil industry, in particular, compositions for enhanced oil recovery.

The aim of the invention is to increase the efficiency of oil displacement from a formation containing asphalt, resin, and paraffin substances.

For this, a microemulsion containing a hydrocarbon, a surfactant, isopropyl alcohol, and one electrolyte solution contains a 4,4-dimethyl-1,3-dioxane (DMD) fraction as a hydrocarbon, and ethoxylated alkylphenol as a surfactant. AF-12 in the following ratio of components, vol.%:

Fraction 4,4-dimethyl1, 3-dioxane25.0-40.0

Ethoxylated

alkylphenol AF-128,0-13,0

Isopropyl alcohol2,6-5,6

1% aqueous solution

sodium chloride Else

The 4,4-dimethyl-1,3-dioxane fraction is a waste from the production of isoprene. The content of pure 4,4-dimethyl-1,3-dioxane in the fraction of 40-60 vol.%, The rest is not identifiable components of this production. The fraction is a clear liquid with a strong odor, density 950-970 kg / m and boiling point 120 -130 ° C.

A microemulsion is prepared by mixing the starting components in any order.

The properties of the microemulsion are tested under laboratory conditions.

To study the dissolving ability of a cassette-resin substance, natural oil with a density of 906 kg / m, having a viscosity at 20 ° C is 59.43 10. Pour point 34 ° C, containing, in wt.%; paraffin 16.5; sulfur 3.57; nitrogen 0.31, resin 13.6; asphaltenes 3.7, mixed with this microemulsion in various ratios, and measuring the viscosity of the mixture. The results are shown in Table. one;

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At a microemulsion concentration in oil of 1.0% by volume or more, its viscosity decreases as compared to pure oil. The presence of a solvent contributes to the dissolution of particles of asphaltenes and paraffin, which are in oil.

To determine the dependence of the oil saturation temperature of paraffins on the emulsion concentration in it, the change in volume of a homogeneous system during the process of dissolving the oil emulsion is measured. The variation of the volume of a single-phase system with temperature is linear, and with the formation of the second phase, this pattern is violated. The addition of a microemulsion to oil lowers the saturation temperature of the oil with paraffin and with increasing concentration of the emulsion the saturation temperature decreases. Thus, the microemulsion does not contribute to the formation of paraffin and will prevent it from falling out in the reservoir and wellbore (see tab.1).

The change in the surface activity of the oil under study, when it is mixed with a microemulsion, is evaluated by the surface tension at the interface of the oil – distilled water and the mixture of oil with the microemulsion — distilled water. The presence of a microemulsion in oil reduces the amount of surface tension (see Table 1).

Example. The microemulsion according to the invention is examined in laboratory conditions on natural cores on two models of the formation. Model 1 is a carbonate core with a porosity of 13.8% and a permeability of 0.440 µm, a model 2 is a hydrogen core with a porosity of 24.8% and a permeability of 1.170 µm. Studies performed at.

Cores are saturated with kerosene and then replaced with natural oil. Postopy

The determination of the applied core by the model pumps the microemulsion composition under study in an amount of 3 pore volumes of the model. The microemulsion is washed out with 4 porous volumes of water and the displacement coefficients are determined. At the same time, the composition of the prototype is tested.

The compositions and properties of the microemulsion are given in table. 2

10 The highest efficacy is achieved using compounds 2-4, 9-10 and 12-14. For these compositions, high stability is characteristic, oil displacement coefficients within the limits of

15 the concentration of the components of the microemulsion according to the invention. Compared with the prototype, this microemulsion allows for oil recovery factors of 1.1-1.34 times the carbonate yield and up to 1.1

20 times for terrigenous reservoirs.

FORUMUA AND 3 ABOUT AND

A microemulsion for displacing oil, 25 containing a hydrocarbon, a surfactant, isopropyl alcohol and an aqueous solution of sodium chloride, characterized in that, in order to increase the efficiency of displacing 30 oil from a formation containing asphalt-paraffin substances, as hydrocarbons it contains a fraction of 4,4-dimethyl-1,3-dioxane, as a surfactant, ethoxylated alkylphenol with the following ratio of components, vol.%.: 4,4-dimethyl-1,3-dioxane fraction 25.0 -40,0

Ethoxylated alkylphenol8,0-13,0

40Isopropyl alcohol2,6-5,0

An aqueous solution of sodium chloride Else.

Table 1

T and l and c and 2 -; Continuation of tab., 2

Claims (1)

Claim A microemulsion for oil displacement containing hydrocarbon, surfactant, surfactant, isopropyl alcohol and an aqueous solution of sodium chloride, characterized in that, in order to increase the efficiency of oil displacement from the reservoir containing asphalt-resin-paraffin substances, it contains fraction 4 as a hydrocarbon , 4-dimethyl-1,3-dioxane, as a surfactant, ethoxylated alkyl phenol in the following ratio of components, vol.% .: 4.4-dime fraction tyl-1,3-dioxane Oxyethylated 25.0-40.0 alkyl phenol 8.0-13.0 Isopropyl alcohol Aqueous solution 2.6-5.0 sodium chloride Rest. Table! Concentration [Microemulsions in oil, vol. % 0,0 0.1 1.0 3.0 10.0 20,0 25.0 Viscosity, 10 ⁶ m ² / s 49.92 49.2 47.52 40.11: 35.53 20.25 Solution solution went around Saturation temperature ° C 20,0 - 18.9 18.0; 17.0 16.1 Solution solution went around Superficial I tension, mN / m 2,5 2.1 1.13 0.84 0.75 0.68 - Table 2 $ Examples : I L The composition of the emulsion, vol. % Appearance DMD Faction AF-12 Isopropyl alcohol 1% aqueous solution of NaCf 1 20 8 2.6 Rest Single phase 2 35 8 2.6 Also Also 3 32,5 10.5 3.8 4 40 thirteen 5,0 Rest Single phase 5 fifty 8 2.6 Bundle 6 25 5 3.0 Single phase 7 25 8 3.0 n Also 8 25 10 '3.0 - - _ 9 25 thirteen 3.0 <♦ 10 25 fifteen 3.0 eleven _ "♦ _ eleven thirty 9 2.0 P Bundle 12 thirty thirteen 2.6 -. Single phase thirteen thirty thirteen 3.0 Also 14 thirty thirteen 5,0 _n fifteen 35 8 5.5 - ”- Single phase 16 (prototype) 30 (liquid top __________ l and in) _____ 14 (surfactant) 7.0 2% NaCI Continuation of the table, 2 Examples Density, kg / m ³ Viscosity X X10 ⁶ m ² / s Surface tension, mn / m The efficiency of oil recovery,% model 1 model 2 1 975 5.97 0.33 79 67 2 970 5.85 0.32 91 89 3 965 6.25 0.35 94 93 4 960 8.04 0.37 97 97 5 - - - 6 968 5.95 0.33 78 80 7 971 5.86 0.32 80 82 8 967 5.87 0.33 85 84 9 962 6.05 0.34 92 97 10 961 6.20 0.35 91 92 eleven - - - - 12 962 6.05 0.34 92 93 thirteen 968 6.20 0.34 95 96 14 960 8.0 0.38 97 96 fifteen - - - - - 16 (prototype) 985 8.0 8.2 78 88