1. An oil-soluble viscosity reducer for thick oil, comprising a fatty acid, a fatty acid ester, and a solvent, the range of the number of carbon atoms of the fatty acid and the range of the number of carbon atoms of a fatty acid moiety in the fatty acid ester being independently 12 to 24.

2. The viscosity reducer for thick oil soluble according to claim 1, wherein the mass ratio of the fatty acid to the fatty acid ester is 10:1-2: 1.

3. The viscosity reducer for thick oil soluble according to claim 1 or 2, wherein the fatty acid is at least one of lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, and linoleic acid.

4. The viscosity reducer for thick oil soluble according to any one of claims 1 to 3, wherein the fatty acid is a fatty acid derived from a plant.

5. The viscosity reducer for thick oil soluble according to claim 4, wherein the fatty acid is derived from at least one of cottonseed oil, rapeseed oil, soybean oil, sunflower seed oil, palm oil, peanut oil and corn oil.

6. The viscosity reducer for thick oil soluble according to any one of claims 1 to 5, wherein the fatty acid ester comprises at least one selected from methyl palmitate, ethyl palmitate, methyl stearate and ethyl stearate.

7. The viscosity reducer for thick oil soluble according to any one of claims 1 to 6, wherein the solvent comprises at least one of thin oil, gasoline, kerosene, diesel oil and light diesel oil.

8. The viscosity reducer for thick oil soluble according to any one of claims 1 to 7, wherein the solvent is 60 to 90 mass% based on 100% of the total mass of the viscosity reducer for thick oil soluble.

9. Use of the oil-soluble viscosity reducer according to any one of claims 1 to 8 in viscosity reduction of thick oil.

10. The use according to claim 9, wherein the mass ratio of the oil-soluble viscosity reducer to the thick oil is 4:5 to 1: 5.

Background

The thickened oil has the characteristics of high density, high solidification point, high viscosity and difficult flowing, so that the difficulty in mining and transporting the thickened oil is high. Therefore, the thickened oil must be modified or modified by physical or chemical methods, and the viscosity is reduced to achieve the aim of smooth recovery. At present, the common heavy oil recovery methods at home and abroad comprise a thermal recovery method, a thin oil blending method, a chemical viscosity reduction method and the like. However, the conventional heavy oil recovery method has many problems, for example, the conventional thermal recovery technology has high energy consumption, and particularly, a pipe condensation accident is easy to occur when the transportation is stopped and started, so that the integrated requirements of heavy oil recovery and transportation are difficult to meet; the thin oil blending method blends the light crude oil after dehydration treatment into mixed water-containing oil, needs to dehydrate again, increases energy consumption, and reduces the physical property of the thin crude oil after blending. The chemical viscosity reducing method is a method for reducing the viscosity of thick oil by adding a chemical agent into the thick oil, and the technology is simple in construction and low in operation cost, and is the most promising viscosity reducing technology at present. Commonly used chemical viscosity reducers include catalytic viscosity reducers, emulsifying viscosity reducers, oil soluble viscosity reducers, and the like.

The oil-soluble viscosity reducer permeates among colloid or asphaltene molecular layers, plays a role in reducing the viscosity of the thickened oil by destroying or weakening aggregation state associations among macromolecules such as the thickened oil colloid, the high-melting-point wax, the asphaltene and the like, and has the advantages of small addition amount, simplicity, high efficiency and less pollution.

Currently, oil-soluble viscosity reducers are mainly of two main types, namely homopolymers or copolymers of condensation type and unsaturated monomers.

Patent CN101007939 reports an oil-soluble viscosity reducer for thick oil. The technical scheme is as follows: the composition is prepared from the following components in percentage by weight: (1) solvent oil, the proportion is 50% to 90%; (2) benzene, in a proportion of 5% to 15%; (3) heterocycles, in a proportion of 5% to 10%; (4) diesel oil, proportion 5% to 15%; (5) span-80, in a proportion of 0.5% to 1.5%. The viscosity reducer takes a solvent as a main component, can play a good dissolving role in colloid asphaltene molecular aggregates, can partially solve the production problem of the initial exploitation of thick oil, but has relatively poor dispersion effect on macromolecules, large dosage and short validity period.

Patent CN102002353A reports an oil-soluble viscosity reducer for thick oil. The viscosity reducer consists of one or more long-chain fatty acid esters, and the carbon atom number of the fatty acid part forming the fatty acid ester is 2 to 30; the viscosity reducer can reduce the viscosity of the thickened oil by more than 55% within 0.2% of the total amount of the thickened oil, and has good viscosity reducing effect. However, the viscosity reducer uses the fatty acid ester alone in a relatively large amount, so that the cost of the viscosity reducer is increased.

Patent CN102363726A reports an oil-soluble viscosity reducer for thick oil. The viscosity reducer is synthesized by maleic anhydride, p-hydroxyanisole, acrylic acid, p-toluenesulfonic acid, azobisisobutyronitrile, toluene, dichloroethane and other components through a series of chemical reactions.

In the document, "synthesis and indoor evaluation of thick oil soluble viscosity reducer MASM" (zhangfengying [ J ] fine petrochemical engineering progress, 2005(12):5-7+11), Maleic Anhydride (MA), Methyl Methacrylate (MMA), styrene (St), and Acrylamide (AM) are used as raw materials, toluene is used as a solvent, and azobisisobutyronitrile is used as an initiator to perform copolymerization reaction, so as to prepare a MA/MMA/St/AM quadripolymer; and then carrying out ester exchange reaction on the MA/MMA/St/AM quadripolymer and octadecanol by taking p-toluenesulfonic acid as a catalyst to prepare the comb polymer viscosity reducer MASM. When the addition amount is 300mg/L, the viscosity reduction rate reaches 90.5 percent.

According to the synthesis and indoor evaluation of the oil-soluble viscosity reducer for the Tahe oil field (Xiagui [ J ] chemical engineering and equipment, 2009(03): 65-67), the SMSA-N five-membered copolymer oil-soluble thick oil viscosity reducer is synthesized, and when the indoor evaluation dosing concentration is 1.0 wt%, the viscosity reduction rate can reach more than 60%.

Most of the oil-soluble viscosity reducers are obtained by condensation or polymerization, so that the synthesis process is complex and the raw material cost is high.

Disclosure of Invention

One of the present invention provides an oil-soluble viscosity reducer for thick oil, comprising a fatty acid, a fatty acid ester and a solvent, wherein the number of carbon atoms of the fatty acid ranges from 12 to 24 independently from the number of carbon atoms of a fatty acid moiety in the fatty acid ester.

In a specific embodiment, the mass ratio of the fatty acid to the fatty acid ester is from 10:1 to 2: 1.

In one embodiment, the fatty acid is at least one of lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, and linoleic acid.

In a specific embodiment, the fatty acid is a fatty acid derived from a plant.

In a specific embodiment, the fatty acid is derived from at least one of cottonseed oil, rapeseed oil, soybean oil, sunflower oil, palm oil, peanut oil and corn oil.

In one embodiment, the fatty acid ester includes at least one selected from the group consisting of methyl palmitate, ethyl palmitate, methyl stearate and ethyl stearate.

The fatty acid methyl ester (or ethyl ester) can be prepared by the ester exchange reaction of vegetable oil such as cottonseed oil, rapeseed oil, soybean oil, sunflower seed oil and palm oil with industrial methanol (or ethanol) under the action of a catalyst, so as to obtain the fatty acid ester which can be used as the viscosity reducer of oil-soluble thick oil. Wherein the cottonseed oil mainly comprises fatty acids of myristic acid, palmitic acid, stearic acid, arachidic acid, oleic acid and linoleic acid. The rapeseed oil mainly comprises several fatty acids of palmitic acid, arachidic acid, stearic acid, oleic acid, linoleic acid, erucic acid and linolenic acid. The soybean oil mainly comprises several fatty acids of palmitic acid, oleic acid, stearic acid, linoleic acid, arachidic acid and linolenic acid. The sunflower seed oil mainly comprises several fatty acids of palmitic acid, oleic acid, stearic acid, linoleic acid and arachidic acid. Palm oil mainly comprises several fatty acids of palmitic acid, stearic acid, oleic acid, linoleic acid, lauric acid and myristic acid. The peanut oil mainly comprises oleic acid, linoleic acid, linolenic acid, palmitic acid, stearic acid and several fatty acids of arachidic acid. The corn oil mainly comprises several fatty acids of palmitic acid, oleic acid and linoleic acid.

In one embodiment, the solvent comprises at least one of thin oil, gasoline, kerosene, diesel oil, and light diesel oil.

In a specific embodiment, the mass percentage of the solvent is 60-90% by taking the total mass of the oil-soluble thick oil viscosity reducer as 100%.

The second invention provides the application of the oil-soluble thick oil viscosity reducer in viscosity reduction of thick oil.

In a specific embodiment, the mass ratio of the oil-soluble thick oil viscosity reducer to the thick oil is 4:5 to 1: 5.

The invention has the beneficial effects that:

the oil-soluble viscosity reducer disclosed by the invention mainly comprises fatty acid and fatty acid ester, is wide in raw material source, clean and safe, simple in preparation process, easy to operate and low in cost, can reduce the viscosity of the thickened oil by more than 42% when the addition of the fatty acid and the fatty acid ester is 0.08% of the total amount of the thickened oil, and has a good viscosity reduction effect. The oil-soluble viscosity reducer is particularly suitable for reducing viscosity of a shaft, can greatly save the using amount of thin oil, and saves the exploitation cost.

Detailed Description

The present invention is further illustrated by the following examples, which are intended to be purely exemplary of the invention and are not to be construed as limiting the invention in any way.

Unless otherwise specified, the reagents used in the following examples are commercially available.

Example 1

In this embodiment, the oil-soluble viscosity reducer is composed of the following components in percentage by mass: 30% of palmitic acid, 6% of stearic acid, 0.3% of oleic acid, 3.7% of ethyl palmitate and 60% of kerosene. The mass ratio of fatty acid to fatty acid ester was 9.81: 1. The preparation method of the oil-soluble viscosity reducer comprises the following steps:

adding 30 kg of palmitic acid, 6 kg of stearic acid and 0.3 kg of oleic acid into 60 kg of kerosene, and stirring for 60 minutes at the temperature of 45 ℃ to completely dissolve the palmitic acid, the stearic acid and the oleic acid; and then 3.7 kg of ethyl palmitate is added into the solution, the mixture is continuously stirred for 60 minutes at the temperature of 45 ℃, and 100 kg of oil-soluble viscosity reducer is obtained after complete dissolution, wherein the mass content of the effective components is 40%.

Example 2

In this embodiment, the oil-soluble viscosity reducer is composed of the following components in percentage by mass: 26% of palmitic acid, 0.67% of myristic acid, 13.3% of methyl palmitate and 60% of kerosene. The mass ratio of fatty acid to fatty acid ester was 2.00: 1. The preparation method of the oil-soluble viscosity reducer comprises the following steps:

adding 26 kg of palmitic acid and 0.67 kg of myristic acid into 60 kg of kerosene, and stirring for 50 minutes at the temperature of 40 ℃ to completely dissolve the palmitic acid and the myristic acid; and adding 13.3 kg of methyl palmitate into the solution, continuously stirring for 50 minutes at the temperature of 40 ℃, and completely dissolving to obtain 100 kg of oil-soluble viscosity reducer, wherein the mass content of the effective components is 40%.

Example 3

In this embodiment, the oil-soluble viscosity reducer is composed of the following components in percentage by mass: 3% of palmitic acid, 6% of stearic acid, 0.09% of arachidic acid, 0.91% of methyl stearate and 90% of diesel oil. The mass ratio of fatty acid to fatty acid ester was 9.99: 1. The preparation method of the oil-soluble viscosity reducer comprises the following steps:

adding 3 kg of palmitic acid, 6 kg of stearic acid and 0.09 kg of arachidic acid into 90 kg of diesel oil, and stirring for 30 minutes at the temperature of 20 ℃ to completely dissolve; and then 0.91 kg of methyl stearate is added into the solution, the mixture is continuously stirred for 30 minutes at the temperature of 20 ℃, and 100 kg of oil-soluble viscosity reducer is obtained after complete dissolution, wherein the mass content of the effective components is 10%.

Example 4

In this embodiment, the oil-soluble viscosity reducer is composed of the following components in percentage by mass: 3% of linoleic acid, 3% of stearic acid, 0.67% of oleic acid, 1.11% of ethyl palmitate, 2.22% of methyl stearate and 90% of gasoline. The mass ratio of fatty acid to fatty acid ester was 2.00: 1. The preparation method of the oil-soluble viscosity reducer comprises the following steps:

adding 3 kg of linoleic acid, 3 kg of stearic acid and 0.67 kg of oleic acid into 90 kg of gasoline, and stirring for 45 minutes at the temperature of 30 ℃ to completely dissolve the linoleic acid, the stearic acid and the oleic acid; and then adding 1.11 kg of ethyl palmitate and 2.22 kg of methyl stearate into the solution, continuously stirring for 40 minutes at the temperature of 30 ℃, and completely dissolving to obtain 100 kg of oil-soluble viscosity reducer, wherein the mass content of the active ingredients is 10%.

Example 5

In this embodiment, the oil-soluble viscosity reducer is composed of the following components in percentage by mass: 7.27% of myristic acid, 20% of stearic acid, 2% of ethyl palmitate, 0.73% of ethyl stearate and 70% of diesel oil. The mass ratio of fatty acid to fatty acid ester was 9.99: 1. The preparation method of the oil-soluble viscosity reducer comprises the following steps:

adding 7.27 kg of myristic acid and 20 kg of stearic acid into 70 kg of diesel oil, and stirring for 50 minutes at the temperature of 40 ℃ to completely dissolve the myristic acid and the stearic acid; and then 2 kg of ethyl palmitate and 0.73 kg of ethyl stearate are added into the solution, and the mixture is continuously stirred for 35 minutes at the temperature of 45 ℃ and is completely dissolved to obtain 100 kg of oil-soluble viscosity reducer, wherein the mass content of the active ingredients is 30%.

Example 6

In this embodiment, the oil-soluble viscosity reducer is composed of the following components in percentage by mass: 15% of palmitic acid, 10% of stearic acid, 5% of arachidic acid, 5% of methyl palmitate, 5% of ethyl palmitate and 70% of diesel oil. The mass ratio of fatty acid to fatty acid ester was 3: 1. The preparation method of the oil-soluble viscosity reducer comprises the following steps:

adding 15 kg of palmitic acid, 10 kg of stearic acid and 5 kg of arachidic acid into 70 kg of diesel oil, and stirring at 45 ℃ for 60 minutes to completely dissolve the palmitic acid, the stearic acid and the arachidic acid; and then 5 kg of methyl palmitate and 5 kg of ethyl palmitate are added into the solution, the mixture is continuously stirred for 40 minutes at the temperature of 45 ℃, and 100 kg of oil-soluble viscosity reducer is obtained after complete dissolution, wherein the mass content of the active ingredients is 30%.

Example 7

In this embodiment, the oil-soluble viscosity reducer is composed of the following components in percentage by mass: 10% of palmitic acid, 8% of stearic acid, 0.18% of lauric acid, 1% of methyl palmitate, 0.82% of ethyl stearate and 80% of thin oil. The mass ratio of fatty acid to fatty acid ester was 9.99: 1. The preparation method of the oil-soluble viscosity reducer comprises the following steps:

adding 10 kg of palmitic acid, 8 kg of stearic acid and 0.18 kg of lauric acid into 80 kg of thin oil, and stirring for 50 minutes at the temperature of 40 ℃ to completely dissolve the palmitic acid, the stearic acid and the lauric acid; and then adding 1 kg of methyl palmitate and 0.82 kg of ethyl stearate into the solution, continuously stirring for 40 minutes at the temperature of 40 ℃, and completely dissolving to obtain 100 kg of oil-soluble viscosity reducer, wherein the mass content of the effective components is 20%.

Example 8

In this embodiment, the oil-soluble viscosity reducer is composed of the following components in percentage by mass: palmitic acid 8%, palmitic acid 3.33%, linoleic acid 2%, methyl palmitate 3%, ethyl palmitate 3%, methyl stearate 0.67%, and diesel oil 80%. The mass ratio of fatty acid to fatty acid ester was 2.00: 1. The preparation method of the oil-soluble viscosity reducer comprises the following steps:

adding 8 kg of palmitic acid, 3.33 kg of palmitic acid and 2 kg of linoleic acid into 80 kg of diesel oil, and stirring for 60 minutes at the temperature of 30 ℃ to completely dissolve the palmitic acid, the palmitic acid and the linoleic acid; and then adding 3 kg of methyl palmitate, 3 kg of ethyl palmitate and 0.67 kg of methyl stearate into the solution, continuously stirring for 40 minutes at the temperature of 30 ℃, and completely dissolving to obtain 100 kg of oil-soluble viscosity reducer, wherein the mass content of the effective components is 20%.

Example 9

In this example, the oil-soluble viscosity-reducing agent is prepared by the following method: 20 kg of linoleic acid is added into 80 kg of diesel oil, and the mixture is stirred for 60 minutes at the temperature of 30 ℃ to be completely dissolved, so that 100 kg of oil-soluble viscosity reducer is obtained after the complete dissolution, and the mass content of the effective components is 20%.

Example 10

In this example, the oil-soluble viscosity-reducing agent is prepared by the following method: 20 kg of stearic acid is added into 80 kg of diesel oil, and the mixture is stirred for 60 minutes at the temperature of 30 ℃ to be completely dissolved, so that 100 kg of oil-soluble viscosity reducer is obtained after the complete dissolution, and the mass content of the effective components is 20%.

Example 11

In this example, the oil-soluble viscosity-reducing agent is prepared by the following method: 20 kg of oleic acid is added into 80 kg of diesel oil, and the mixture is stirred for 60 minutes at the temperature of 30 ℃ to be completely dissolved, so that 100 kg of oil-soluble viscosity reducer is obtained after the complete dissolution, and the mass content of the effective components is 20%.

Example 12

In this example, the oil-soluble viscosity-reducing agent is prepared by the following method: 20 kg of myristic acid is added into 80 kg of diesel oil, and the mixture is stirred for 60 minutes at the temperature of 30 ℃ to be completely dissolved, so that 100 kg of oil-soluble viscosity reducer is obtained after the mixture is completely dissolved, and the mass content of the effective components is 20%.

Example 13

In this example, the oil-soluble viscosity-reducing agent is prepared by the following method: 20 kg of palmitic acid is added into 80 kg of diesel oil, and the mixture is stirred for 60 minutes at the temperature of 30 ℃ to be completely dissolved, so that 100 kg of oil-soluble viscosity reducer is obtained after complete dissolution, and the mass content of the active ingredients is 20%.

Example 14

In this example, the oil-soluble viscosity-reducing agent is prepared by the following method: adding 20 kg of palmitic acid into 80 kg of diesel oil, stirring for 60 minutes at the temperature of 30 ℃ to completely dissolve the palmitic acid, and obtaining 100 kg of oil-soluble viscosity reducer after complete dissolution, wherein the mass content of active ingredients is 20%.

Example 15

In this example, the oil-soluble viscosity-reducing agent is prepared by the following method: 20 kg of arachidic acid is added into 80 kg of diesel oil, and the mixture is stirred for 60 minutes at the temperature of 30 ℃ to be completely dissolved, so that 100 kg of oil-soluble viscosity reducer is obtained after complete dissolution, and the mass content of the effective components is 20%.

Example 16

In this example, the oil-soluble viscosity-reducing agent is prepared by the following method: 20 kg of lauric acid is added into 80 kg of diesel oil, and the mixture is stirred for 60 minutes at the temperature of 30 ℃ to be completely dissolved, so that 100 kg of oil-soluble viscosity reducer is obtained after complete dissolution, and the mass content of the effective components is 20%.

Example 17

In this example, the oil-soluble viscosity-reducing agent is prepared by the following method: 20 kg of ethyl palmitate is added into 80 kg of diesel oil, and the mixture is stirred for 60 minutes at the temperature of 30 ℃ to be completely dissolved, so that 100 kg of oil-soluble viscosity reducer is obtained after the complete dissolution, and the mass content of the effective components is 20%.

Example 18

In this example, the oil-soluble viscosity-reducing agent is prepared by the following method: 20 kg of methyl palmitate is added into 80 kg of diesel oil, and the mixture is stirred for 60 minutes at the temperature of 30 ℃ to be completely dissolved, so that 100 kg of oil-soluble viscosity reducer is obtained after the complete dissolution, and the mass content of the effective components is 20%.

Example 19

In this example, the oil-soluble viscosity-reducing agent is prepared by the following method: adding 20 kg of methyl stearate into 80 kg of diesel oil, stirring for 60 minutes at the temperature of 30 ℃ to completely dissolve the methyl stearate, and obtaining 100 kg of oil-soluble viscosity reducer after complete dissolution, wherein the mass content of active ingredients is 20%.

Example 21

In this example, the oil-soluble viscosity-reducing agent is prepared by the following method: adding 20 kg of ethyl stearate into 80 kg of diesel oil, stirring for 60 minutes at the temperature of 30 ℃ to completely dissolve the ethyl stearate, and obtaining 100 kg of oil-soluble viscosity reducer after complete dissolution, wherein the mass content of active ingredients is 20%.

Example 22

Performance testing

Thick oil: in order to facilitate viscosity measurement, a certain amount of original tower and river thick oil is measured, and the viscosity of the tower and river thick oil is diluted by adding the same volume of thin oil for viscosity reduction experiments.

And (3) carrying out viscosity measurement on the diluted thick oil by adopting a DV-3T type viscometer under a constant-temperature circulating water bath at 50 ℃ to obtain the initial viscosity of each thick oil.

According to the amount that the effective content of the oil-soluble viscosity reducer (namely the addition amount of fatty acid and/or fatty acid ester in the thick oil viscosity reducer) accounts for 0.08 percent of the total mass percent, the thick oil and the oily viscosity reducer in the examples 1 to 21 are uniformly mixed, are heated and rolled for 4 hours in a roller furnace at the temperature of 90 ℃, are cooled to the temperature of 50 ℃, and are subjected to viscosity measurement by adopting a DV-3T type viscometer, so that the viscosity of the viscosity reducer is obtained.

Viscosity reduction rate (initial viscosity-viscosity after addition of a viscosity reducing agent)/initial viscosity X100%

The results are shown in Table 1.

TABLE 1 viscosity reduction Effect of different formulations

The results in table 1 show that the addition of the effective content of the thick oil viscosity reducer of the invention is not more than 0.08 percent of the total mass of the thick oil, the dosage of the viscosity reducer is small, the viscosity of the thick oil can be reduced by more than 42 percent, and the viscosity reducing effect is good.

While the invention has been described with reference to specific embodiments, those skilled in the art will appreciate that various changes can be made without departing from the true spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation, material, composition of matter, and method to the essential scope and spirit of the present invention. All such modifications are intended to be included within the scope of the present invention as defined in the appended claims.