disclosure of Invention
Aiming at the problems that the existing oil-based wax inhibitor has high toxicity, low content of wax crystal improver and is inflammable; the water-based wax inhibitor has poor field application effect, short wax-proof period and high dosing concentration; the invention discloses a nano-particle wax-proof pour point depressant for an oil well, and provides a preparation method and application of the nano-particle wax-proof pour point depressant for the oil well.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
The nano-particle wax-proofing pour point depressant for the oil well comprises the following components in percentage by mass:
20 to 25 percent of wax crystal modifier;
5 to 10 percent of emulsifier;
5 to 10 percent of penetrating agent;
12 to 18 percent of scale remover;
20% -25% of a diluent;
the balance being water.
The wax crystal modifier is preferably an oleate-styrene-maleic anhydride terpolymer, and the molecular weight of the oleate-styrene-maleic anhydride terpolymer is 24000-29000.
Specifically, the molar ratio of the oleate-styrene-maleic anhydride terpolymer monomer is as follows: oleate: styrene: maleic anhydride (2-2.4): (1-1.2): (0.9-1.1).
Further, the emulsifier is one of polyoxyethylene laurate or a condensate of fatty alcohol and ethylene oxide; preferably, the emulsifier is polyoxyethylene laurate LAE-4, the content of active ingredients is 99%, the molecular weight is 220-20000, and the saponification value is 145-155 mgKOH/g. The content of the active ingredients of the fatty alcohol and ethylene oxide condensate is 99%, the molecular weight is 210-20000, and the saponification value is 150-160 mgKOH/g.
Further, the penetrating agent is a condensation product of fatty alcohol and ethylene oxide, the molecular weight is 500-30000, preferably, the penetrating agent is JFC-2, and the penetrating power of a 0.1% aqueous solution of the penetrating agent is less than or equal to 3 seconds; or selecting penetrant OE-35 with 4g/L water solution penetration force of less than or equal to 4 s.
Further, the scale remover is preferably ethyl acetate or propyl acetate, and the effective content of the scale remover is 99%.
Further, the diluent is preferably methanol or ethanol, and the effective content of the diluent is 99%.
the nano-particle wax-proofing pour point depressant for the oil well comprises the following components in percentage by mass:
20-25% of a wax crystal modifier, wherein the wax crystal modifier is an oleate-styrene-maleic anhydride terpolymer;
5-10% of emulsifier, wherein the emulsifier is polyoxyethylene laurate;
5-10% of penetrant, wherein the penetrant is alkylphenol polyoxyethylene ether penetrant;
12-18% of a scale remover, wherein the scale remover is ethyl acetate;
20% -25% of a diluent, wherein the diluent is methanol;
the balance being water.
A preparation method of a nanoparticle wax control pour point depressant for an oil well comprises the following steps:
Step 1) sequentially adding a wax crystal improver, an emulsifier, a penetrant, a descaling agent and water in a reaction kettle according to the formula amount;
And 2) starting a stirring device of the acid-alkali resistant enamel reaction kettle, heating to 30-70 ℃ at a stirring speed of 300-600 r/min, stopping heating after reacting for 10-40 minutes, adding a diluent in a formula amount, continuously stirring for 20-40 minutes, and cooling to room temperature to obtain the nano-particle wax-proof pour point depressant for the oil well.
the application of the nano-particle wax-proof pour point depressant for the oil well is used for wax prevention of the oil well and pour point depression treatment of crude oil in the crude oil production process, and the nano-particle wax-proof pour point depressant for the oil well is directly added into an oil well annulus or an oil pipeline during the treatment, wherein the adding amount of the nano-particle wax-proof pour point depressant for the oil well is 0.05-0.1% of the volume of the crude oil.
The invention has the following beneficial effects:
1. The wax-proof pour point depressant (oleate-styrene-maleic anhydride terpolymer) in the raw material composition can be adsorbed with wax crystals in crude oil to generate distortion, and a network structure is not easy to form, so that the low-temperature fluidity of the crude oil is improved, and the wax precipitation period of an oil well is prolonged.
2. The emulsifier in the raw material composition has the effective component content of 99 percent, the HLB value of 9-10 and the saponification value of 145-155 mgKOH/g; a water film can be formed on the pipe wall, and wax crystals are prevented from being attached to the pipe wall. Has good emulsifying, wetting, solubilizing, dispersing and plasticizing performances.
3. the penetrating agent in the raw material composition can improve the penetrating capability of the oil-soluble high molecular organic polymer in the crude oil.
4. the scale remover in the raw material composition is hydrolyzed after being contacted with crude oil in an oil well, so that carbonate scale in a shaft can be effectively cleaned, the smoothness of the shaft is kept, and wax crystals are prevented from being aggregated and adsorbed at a scale forming part.
5. the diluent in the raw material composition can reduce the condensation point and the viscosity of the product.
6. The oil well nano-particle wax-proof pour point depressant of the invention can uniformly disperse an oil-soluble wax crystal improver in a water phase with the particle size of 20-60 nanometers under the action of a surfactant penetrant, the produced nano-particle wax-proof scale remover is uniform and transparent and does not contain aromatic organic solvents, and after the oil well nano-particle wax-proof pour point depressant is added into an oil well with serious wax precipitation and scaling, the oil well nano-particle wax-proof pour point depressant can quickly react with wax crystals in crude oil, thereby reducing the viscosity of the crude oil, reducing the adsorption of the wax crystals and the scale crystals on the wall of an oil well pipe, prolonging the pump inspection period of the oil well and improving the production efficiency of the oil well.
7. The nano-particle wax-proof pour-point depressant for the oil well is used for wax prevention of the oil well and treatment of pour point depression of crude oil in the crude oil production process, and is directly added into the annular space of the oil well or an oil pipeline during treatment, so that the agent can continuously act on the well bottom and is mixed with crude oil produced from a shaft, the wax-proof effect is exerted, and the wax precipitation period of the oil well is effectively prolonged.
8. when the nano-particle wax-proof pour point depressant for the oil well is used for wax-proof and scale removal of the oil well, the pump detection period of the oil well is prolonged by more than 4 times.
The foregoing description is only an overview of the technical solutions of the present invention, and in order to clearly understand the technical solutions of the present invention and to implement the technical solutions according to the contents of the description, the following detailed description is given with reference to the preferred embodiments of the present invention and the accompanying drawings.
Detailed Description
The technical features, objects and effects of the present invention will be more clearly understood and appreciated by those skilled in the art, but the technical aspects of the present invention will not be described in detail below, and the present invention is not to be construed as being limited to the implementable scope of the present invention.
The percentages in the examples are given by mass unless otherwise indicated.
first embodiment
The first embodiment of the invention relates to a nano-particle wax control pour point depressant for an oil well, which comprises the following components in percentage by mass:
20 to 25 percent of wax crystal modifier;
5 to 10 percent of emulsifier;
5 to 10 percent of penetrating agent;
12 to 18 percent of scale remover;
20% -25% of a diluent;
The balance being water.
The embodiment protects a preparation method of a nanoparticle wax-proofing pour point depressant for an oil well, which comprises the following steps: 1) sequentially adding a wax crystal improver, an emulsifier, a penetrating agent, a scale remover and water in a reaction kettle according to the formula amount;
2) Starting a stirring device of the acid-alkali resistant enamel reaction kettle, heating to 30-70 ℃ at a stirring speed of 300-600 r/min, stopping heating after reacting for 10-40 minutes, adding a diluent in a formula amount, continuously stirring for 20-40 minutes, and cooling to room temperature to obtain the oil well nano-particle wax-proof pour point depressant.
The oil well nano-particle wax-proof pour point depressant of the invention can uniformly disperse an oil-soluble wax crystal improver in a water phase with the particle size of 20-60 nanometers under the action of a surfactant penetrant, the produced nano-particle wax-proof scale remover is uniform and transparent and does not contain aromatic organic solvents, and after the oil well nano-particle wax-proof pour point depressant is added into an oil well with serious wax precipitation and scaling, the oil well nano-particle wax-proof pour point depressant can quickly react with wax crystals in crude oil, thereby reducing the viscosity of the crude oil, reducing the adsorption of the wax crystals and the scale crystals on the wall of an oil well pipe, prolonging the pump inspection period of the oil well and improving the production efficiency of the oil well.
second embodiment
in addition to the above embodiments, the wax crystal modifier is preferably an oleate-styrene-maleic anhydride terpolymer (manufacturer: chemical group ltd, changqing, west) having a molecular weight of 24000 to 29000. Specifically, the molar ratio of the oleate-styrene-maleic anhydride terpolymer monomer is as follows: oleate: styrene: maleic anhydride (2-2.4): (1-1.2): (0.9-1.1). The wax crystal improver can be adsorbed with wax crystals in crude oil to generate distortion, and a network structure is not easy to form, so that the low-temperature fluidity of the crude oil is improved, and the wax precipitation period of an oil well is prolonged.
Further, the HLB value of the emulsifier is 9-10, and specifically, the emulsifier is polyoxyethylene laurate or one of condensation products of fatty alcohol and ethylene oxide; preferably, the emulsifier is polyoxyethylene laurate LAE-4, the content of active ingredients is 99%, the molecular weight is 220-20000, and the saponification value is 145-155 mgKOH/g. The content of the active ingredients of the fatty alcohol and ethylene oxide condensate is 99%, the molecular weight is 210-20000, and the saponification value is 150-160 mgKOH/g. The emulsifier of the invention can form a water film on the pipe wall, avoids wax crystals from attaching to the pipe wall, and has good emulsifying, wetting, solubilizing, dispersing and plasticizing performances.
further, the penetrating agent is a condensation product of fatty alcohol and ethylene oxide, the molecular weight is 500-30000, preferably, the penetrating agent is JFC-2, and the penetrating power of a 0.1% aqueous solution of the penetrating agent is less than or equal to 3 seconds; or selecting penetrant OE-35 with 4g/L water solution penetration force of less than or equal to 4 s. The penetrating agent can improve the penetrating power of the oil soluble high molecular organic polymer in crude oil.
Further, the scale remover is preferably ethyl acetate or propyl acetate, and the effective content of the scale remover is 99%. The scale remover disclosed by the invention is hydrolyzed after being contacted with crude oil in an oil well, so that carbonate scale in a shaft can be effectively cleaned, the smoothness of the shaft is kept, and wax crystals are prevented from being aggregated and adsorbed at a scale forming part.
Further, the diluent is preferably methanol or ethanol, and the effective content of the diluent is 99%. The diluent of the invention can reduce the condensation point and viscosity of the product.
third embodiment
The embodiment discloses a nano-particle wax-proof pour point depressant for an oil well, which comprises the following components in percentage by mass: 20-25% of oleate-styrene-maleic anhydride terpolymer; 5 to 10 percent of polyoxyethylene laurate; 5 to 10 percent of alkylphenol polyoxyethylene; 12 to 18 percent of ethyl acetate; 20% -25% of methanol; the balance being water.
The embodiment protects a preparation method of a nanoparticle wax-proofing pour point depressant for an oil well, and specifically comprises the following steps of sequentially adding the components in percentage by mass into an acid-and-alkali-resistant enamel reaction kettle with the reaction temperature of 30-70 ℃ and the stirring speed of 300-600 r/min: 20-25% of oleate-styrene-maleic anhydride terpolymer; 5 to 10 percent of polyoxyethylene laurate; 5 to 10 percent of penetrant alkylphenol polyoxyethylene ether; 12 to 18 percent of scale remover ethyl acetate; the balance being water. Under the action of reducing interfacial tension and permeability of polyoxyethylene laurate LAE-4 and a penetrating agent JFC-2, an oleate-styrene-maleic anhydride terpolymer can be uniformly dispersed in a water phase in a particle size of 70-210 nanometers, a diluent (methanol) with the particle size of 20-25 percent is added, and the nano wax-proof pour point depressant is obtained after stirring for 30 minutes.
The embodiment also protects the application of the nano-particle wax-proof pour point depressant for the oil well, which is used for wax prevention of the oil well and treatment of crude oil pour point reduction in the crude oil production process, and the nano-particle wax-proof pour point depressant for the oil well is directly added into the annular space of the oil well or an oil pipeline during the treatment, wherein the adding amount of the nano-particle wax-proof pour point depressant for the oil well is 0.05-0.1% of the volume of the crude oil.
It is worth mentioning that when the nano-particle wax-proof pour point depressant for the oil well is used for wax-proof and scale removal of the oil well, the pump detection period of the oil well is prolonged by more than 4 times.
Fourth embodiment
The embodiment provides a nano-particle wax-proof pour point depressant for an oil well, which comprises the following components in percentage by mass: 25% of oleate-styrene-maleic anhydride terpolymer, 10% of polyoxyethylene laurate LAE-4, 10% of alkylphenol ethoxylate JFC-1, 18% of ethyl acetate, 25% of methanol and 12% of water.
the preparation method of the nanoparticle wax-proofing pour-point depressant for the oil well comprises the steps of sequentially adding an oleate-styrene-maleic anhydride terpolymer, polyoxyethylene laurate LAE-4, alkylphenol ethoxylate JFC-1, ethyl acetate and water in a formula amount into a reaction kettle, starting a stirring device, raising the temperature of the reaction kettle to 50 ℃, reacting for 30 minutes, then adding methanol in a formula amount, and then cooling to room temperature to obtain the nanoparticle wax-proofing pour-point depressant for the oil well.
the performance of the above-mentioned nanoparticle wax control pour point depressant for oil wells of this example was tested indoors. The test method is as follows:
Measurement of appearance
50mL of the sample was placed in a 100mL colorimetric tube and visually observed.
measurement of wax control Rate
the test is carried out according to the test method of the wax-proof rate in SY/T6300-2009 'technical conditions for clear and wax-proof for oil extraction', and the dosing concentration is 0.05%.
Determination of pour Point Degrees
the testing method of pour point depression amplitude in SY/T5767-2016 technical Specification for crude oil pipeline pour point depressant delivery is used for testing, and the dosing concentration is 0.05%.
Determination of corrosion rate of calcium carbonate
The mass recorded for a medium speed quantitative filter paper (dried, weighed after drying, accurate to 0.0001g) is m0。
0.500g of solid calcium carbonate powder (to the nearest 0.001g) was accurately weighed and its mass m was recorded1Putting the weighed scale sample into a 250mL triangular flask with a plug, adding 200g of distilled water and 20.00g of oil well nano-particle wax-proof pour point depressant, shaking uniformly, sealing, and carrying out capping reaction for 1h in a water bath at 60 ℃; reaction ofcooling the solution to room temperature after the end, filtering the solution by using medium-speed quantitative filter paper, washing the solution for 4 to 5 times by using distilled water, putting the filter residue and the filter paper into a 105 ℃ oven, taking out the filter residue and the filter paper after 2 hours, putting the filter residue and the filter paper into a dryer, weighing the filter residue and the filter paper after 30 minutes, and recording the mass of the filter residue as m2。
computing
In the formula:
r-corrosion rate of calcium carbonate,%;
m1-mass of dirty sample, g;
m0-pre-test filter paper mass, g;
m2mass of filter residue and filter paper after test, g.
determination of particle size distribution
The oil well nano-particle wax control pour point depressant is tested by a Malvern Zetasizer NanoZS90 nano-particle size potential analyzer, and the concentration of a test sample is 1.0%.
when the oil well wax control pour point depressant is tested according to the method, as shown in figure 1, the oil well wax control pour point depressant has the following quality technical indexes:
Appearance: a homogeneous stable liquid;
pH value: 6.0;
Wax control rate (0.05%): 86.3 percent;
Viscosity reduction rate (0.05%): 78.9 percent;
pour point depression amplitude (0.05%): 23 ℃;
Corrosion rate of calcium carbonate (60 ℃): 85.7 percent
The median particle diameter (D50) of the oleate-styrene-maleic anhydride terpolymer dispersed in the liquid was 126 nm.
The field test condition:
In 2018, 6 months, the nanoparticle wax control pour point depressant for the oil well is firstly subjected to field tests in a ZB oil field. The test well is a horizontal well, the water content of the corresponding oil well is 23 percent, the hard wax content is 21.6 percent, the condensation point of crude oil is 24 ℃, the average daily liquid production is 7.6 tons, the well flushing period is 14 days, after the nano-particle wax-proofing pour-point depressant for the oil well is added, the average daily oil production is 8.9 tons in 12 months, the condensation point of the crude oil is reduced to 1 ℃, the daily oil increase is 1.3 tons, and the well flushing period is prolonged to about 93 days. The wax control effect is obvious.
fifth embodiment
The embodiment provides a nanoparticle wax control pour point depressant for an oil well, which comprises the following components in percentage by mass: 20% of oleate-styrene-maleic anhydride terpolymer, 5% of polyoxyethylene laurate LAE-4, 8% of alkylphenol ethoxylate JFC-1, 12% of ethyl acetate, 20% of methanol and 35% of water.
the preparation method of the nanoparticle wax-proofing pour-point depressant for the oil well comprises the steps of sequentially adding an oleate-styrene-maleic anhydride terpolymer, polyoxyethylene laurate LAE-4, alkylphenol ethoxylate JFC-1, ethyl acetate and water in a formula amount into a reaction kettle, starting a stirring device, raising the temperature of the reaction kettle to 50 ℃, reacting for 30 minutes, then adding methanol in a formula amount, and then cooling to room temperature to obtain the nanoparticle wax-proofing pour-point depressant for the oil well.
The performance of the inhibitor of the present embodiment was tested indoors, and the quality specifications are as follows:
Appearance: a homogeneous stable liquid;
pH value: 6.0;
Wax control rate (0.05%): 83.4 percent;
viscosity reduction rate (0.05%): 91.8 percent;
pour point depression amplitude (0.05%): 26 ℃;
corrosion rate of calcium carbonate (60 ℃): 89.3 percent
The oil well nano-particle wax control pour point depressant was tested with a malvern zetasizer nanozs90 nano-particle size potential analyzer at a test sample concentration of 1.0% with the following test results shown in fig. 2:
The median particle diameter (D50) of the oleate-styrene-maleic anhydride terpolymer dispersed in the liquid was 131 nm.
The field test condition:
7 months in 2018, the nanoparticle wax-proofing pour point depressant for the oil well is subjected to field test in a JY oil field. The test well is an oil well, the viscosity of crude oil is 269.8mPa.s, the condensation point of the crude oil is 27 ℃, the hard wax content is 26%, the average daily oil yield is 4.8 tons in 3 months before the test, the well flushing period is 17 days, after the nano-particle wax-proof pour point depressant for the oil well is added, the daily oil yield is 6.4 tons, the condensation point of the crude oil is reduced to 1 ℃, the daily oil increment is 1.6 tons, and the well flushing period is prolonged to about 128 days. The wax control effect is obvious.
Sixth embodiment
The embodiment provides a nanoparticle wax control pour point depressant for an oil well, which comprises the following components in percentage by mass: 22% of oleate-styrene-maleic anhydride terpolymer, 8% of polyoxyethylene laurate LAE-4, 5% of alkylphenol ethoxylate JFC-1, 15% of ethyl acetate, 22% of methanol and 28% of water.
The preparation method of the nanoparticle wax-proofing pour-point depressant for the oil well comprises the steps of sequentially adding an oleate-styrene-maleic anhydride terpolymer, polyoxyethylene laurate LAE-4, alkylphenol ethoxylate JFC-1, ethyl acetate and water in a formula amount into a reaction kettle, starting a stirring device, raising the temperature of the reaction kettle to 60 ℃, reacting for 30 minutes, then adding methanol in a formula amount, and then cooling to room temperature to obtain the nanoparticle wax-proofing pour-point depressant for the oil well.
the nano-particle wax-proofing pour-point depressant for the oil well is directly added into the oil well with serious wax precipitation from an oil sleeve annulus, the dosing period is 15 days, the nano-particle wax-proofing pour-point depressant is added according to 0.05-0.1% of the yield of the oil well in 15 days, and a medicament can continuously act on the well bottom and is mixed with crude oil extracted from a shaft, so that the wax-proofing effect is exerted, and the wax precipitation period of the oil well is effectively prolonged.
Seventh embodiment
the embodiment provides a nanoparticle wax control pour point depressant for an oil well, which comprises the following components in percentage by mass: 20% of oleate-styrene-maleic anhydride terpolymer, 8% of LAE-4 polyoxyethylene laurate, 10% of JFC-1 alkylphenol polyoxyethylene ether penetrant, 12% of ethyl acetate, 20% of methanol and 30% of water.
the preparation method of the nanoparticle wax-proofing pour-point depressant for the oil well comprises the steps of sequentially adding an oleate-styrene-maleic anhydride terpolymer, polyoxyethylene laurate LAE-4, alkylphenol ethoxylate JFC-1, ethyl acetate and water in a formula amount into a reaction kettle, starting a stirring device, raising the temperature of the reaction kettle to 60 ℃, reacting for 30 minutes, then adding methanol in a formula amount, and then cooling to room temperature to obtain the nanoparticle wax-proofing pour-point depressant for the oil well.
From the above results, the oil well nano-particle wax-proof pour point depressant of the invention can uniformly disperse the oil-soluble wax crystal improver in the water phase with the particle size of 20-60 nm under the action of the surfactant penetrant, the produced nano-particle wax-proof pour point depressant is uniform and transparent and does not contain aromatic organic solvents, and after the oil well nano-particle wax-proof pour point depressant is added into an oil well with serious wax precipitation and scaling, the oil well nano-particle wax-proof pour point depressant can rapidly react with wax crystals in crude oil, thereby reducing the viscosity of the crude oil, reducing the adsorption of the wax crystals and scale crystals on the wall of the oil well pipe, prolonging the pump inspection period of the oil well and improving the production efficiency of the oil well.
the above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.
In the case of no conflict, a person skilled in the art may combine the related technical features in the above examples according to actual situations to achieve corresponding technical effects, and details of various combining situations are not described herein.