High temperature resistant clay stabilizer for deep expansion prevention of heavy oil thermal recovery and preparation method thereof

Abstract

The present invention provides a high temperature resistant clay stabilizer for preventing expansion in depth of heavy oil thermal recovery and a preparation method thereof. The structure of the stabilizer contains multiple ammonium ions, propylene oxide hydrophobic segments, and temperature-resistant benzene ring structures, and the stabilizer has the advantages of strong adsorption, obvious hydrophobic effect, good temperature resistance, and no chromatographic separation. The high temperature resistant clay stabilizer provided by the present invention has an anti-swelling rate of more than 90%, a temperature resistance of 300°C, a water washability of 100%, and a core permeability retention value of more than 90%. The stabilizer can be used for preventing expansion in depth of heavy oil thermal recovery, and can be used for both oil well expansion control and oil well expansion prevention treatment.

Description

Technical Field

[0001] The invention relates to a high temperature resistant clay stabilizer, a preparation method and application thereof in heavy oil thermal utilization. Background Art

[0002] Clay minerals are widely present in oil layers. 97% of the oil layers in the world contain clay minerals to varying degrees. Generally, when the oil reservoir contains 5% to 20% clay, it is considered to be an oil layer with a high clay content. If improper measures are taken during the development process, clay minerals will expand, disperse and migrate, thereby blocking the throat of the pore structure of the formation, reducing the permeability of the formation and causing formation damage. During the expansion process, clay absorbs water into the crystal structure, resulting in an increase in the volume of clay, thereby blocking the pores of the formation; during the migration process, clay materials are dispersed by foreign liquids or carried by the produced fluid, forming bridge resistance or throttling points at the pore throats of the capillaries, which can easily lead to a decrease in the permeability of the formation. Therefore, for reservoirs with high clay content and strong water sensitivity, any process measures such as drilling, cementing, water injection, fracturing, acidizing, well repair and well pressure, as long as there is intrusion of water-based working fluid, it is possible to cause water-sensitive damage. The most common method to solve water-sensitive damage is to add clay stabilizer to the injected water. Therefore, the research and development and use of high-quality and efficient anti-swelling agents are important measures to ensure stable production of oil fields.

[0003] Sinopec has proven about 10.2 billion tons of heavy oil resources, accounting for 38% of Sinopec's oil resources, mainly distributed in Shengli, Northwest, Henan and other oil fields, which will be the main battlefield for my country's future reserve and production increase. In the process of heavy oil thermal recovery, high-temperature steam needs to be injected, and the temperature reaches 300°C, which puts higher requirements on the temperature resistance of clay stabilizers. At present, commonly used clay stabilizers are widely used to protect the permeability of formations in shallow areas, and the temperature resistance is generally below 200°C. Analysis shows that there are two main possibilities for its insufficient temperature resistance. One is that the thermal stability of the treatment agent itself is insufficient, and it decomposes under high temperature and cannot play an anti-swelling role; the other is that the adsorption of the treatment agent with clay is weakened at high temperature, and it cannot form effective adsorption inside the clay, so the effect becomes worse. Although the method of using several treatment agents for compounding can improve the temperature resistance, there is also a phenomenon of chromatographic separation in the reservoir pores, which leads to unsatisfactory on-site use and cannot achieve the effect of deep anti-swelling. Summary of the invention

[0004] The invention provides a high temperature resistant clay stabilizer for preventing deep expansion of heavy oil thermal recovery and a preparation method thereof. The structure of the high temperature resistant clay stabilizer contains multiple ammonium ions, propylene oxide hydrophobic segments and temperature resistant benzene ring structures, and the stabilizer has the advantages of strong adsorption, obvious hydrophobic effect, good temperature resistance and no chromatographic separation.

[0005] The technical solution adopted by the present invention is: a high temperature resistant clay stabilizer for deep anti-swelling of heavy oil thermal recovery, characterized in that: the molecular structure of the high temperature resistant clay stabilizer contains propylene oxide hydrophobic chain, high temperature resistant benzene ring structure and ammonium ions that can be strongly adsorbed in the formation, and its general structural formula is:

[0006] wherein m is 1-10; R is methyl, ethyl, propyl or butyl; and X is halogen.

[0007] The present invention also provides a method for preparing a high temperature resistant clay stabilizer for deep expansion prevention of heavy oil thermal recovery. The high temperature resistant clay stabilizer is prepared by reacting a tertiary amine containing a propylene oxide hydrophobic chain in its molecular structure with a benzyl halide. The molecular structure of the tertiary amine containing a propylene oxide hydrophobic chain is generally:

[0008]

[0009] wherein m is 1-10; and R is methyl, ethyl, propyl or butyl.

[0010] The reaction conditions of the tertiary amine containing propylene oxide hydrophobic chain and benzyl halide are: reaction temperature 80-90° C., reaction time 2-6 hours, the molar ratio of the tertiary amine to the benzyl halide is 1:2-1:3, preferably 1:2-1:2.3, and the benzyl halide is preferably benzyl chloride.

[0011] The tertiary amine containing propylene oxide hydrophobic chain is prepared by direct reaction of polyether alcohol with dialkylamine in the presence of catalyst and hydrogen. The molecular structure of the polyether alcohol is generally:

[0012]

[0013] Where m is 1-10.

[0014] The reaction conditions of the polyether alcohol and dialkylamine are: the catalyst dosage is 0.1-5%, preferably 0.5-1%; the reaction temperature is 185-245° C., the hydrogen partial pressure is 2.5-4.5 MPa, and the reaction time is 3-6 h.

[0015] The catalyst used for the reaction of the polyether alcohol and dialkylamine is a Ni / Al catalyst, wherein the content of Ni is 25-40%.

[0016] The dialkylamines are dimethylamine, diethylamine, dipropylamine and dibutylamine.

[0017] The high temperature resistant clay stabilizer has a temperature resistance of not less than 300°C and can be used for heavy oil thermal recovery and expansion prevention, and can be used for oil well expansion control as well as expansion prevention treatment.

[0018] The invention provides a high temperature resistant clay stabilizer for deep anti-swelling of heavy oil thermal recovery. Firstly, there are two ammonium ions in the structure of the stabilizer, and the adsorption force between the two ammonium ions and the stratum is much stronger than the lone pair electron effect on the nitrogen of the amine group, and the adsorption force between the two ammonium ions and the stratum is strong. The two ammonium ions can form multiple effects of adsorption with the clay, which is beneficial to enhancing the adsorption of the stabilizer, so that the stabilizer can still be adsorbed inside the clay under high temperature conditions, and play an anti-swelling effect. Secondly, the structure of the stabilizer contains a hydrophobic propylene oxide chain segment. After the stabilizer is adsorbed inside the clay, the hydrophobic property of the propylene oxide chain can not only drive away the water molecules inside the clay, but also prevent the water molecules from entering the clay. Thirdly, a benzene ring structure is introduced into the side chain of the molecular structure, which is beneficial to improving the thermal stability of the structure, and also increases the steric hindrance effect, further weakening the chance of water molecules entering. Fourthly, as a single substance with multiple properties, the chromatographic separation phenomenon inside the reservoir during the injection process is avoided, the performance is kept stable, and the effect of deep anti-swelling can be achieved.

[0019] The temperature-resistant clay stabilizer provided by the invention has good anti-swelling property, temperature resistance and water washing resistance, the anti-swelling rate reaches more than 90%, the temperature resistance reaches 300°C, the water washing resistance rate reaches 100%, and the core permeability retention value reaches more than 90%. DETAILED DESCRIPTION

[0020] The present invention is described in detail below with reference to the embodiments.

[0021] Example 1

[0022] (1) Preparation of tertiary amines containing propylene oxide hydrophobic chains

[0023] The molecular structure of the selected polyether alcohol is:

[0024]

[0025] Where m is 5.

[0026] A Ni / Al catalyst with a Ni content of 30% was selected, the dosage was 1%, the dialkylamine was dimethylamine, the amination reaction temperature was 245°C, the hydrogen partial pressure was 2.5MPa, the reaction time was 4h, and a tertiary amine containing a propylene oxide hydrophobic chain was obtained.

[0027] (2) Preparation of high temperature resistant clay stabilizer

[0028] The tertiary amine containing propylene oxide hydrophobic chain prepared in step (1) is reacted with benzyl chloride at a reaction temperature of 90° C., a ratio of the tertiary amine to the benzyl chloride of 1:2, and a reaction time of 4 h to prepare a high temperature resistant clay stabilizer.

[0029] Example 2

[0030] (1) Preparation of tertiary amines containing propylene oxide hydrophobic chains

[0031] The molecular structure of the selected polyether alcohol is:

[0032]

[0033] Where m is 1.

[0034] A Ni / Al catalyst with a Ni content of 40% was selected, the dosage was 0.1%, the dialkylamine was diethylamine, the amination reaction temperature was 215°C, the hydrogen partial pressure was 4.5MPa, the reaction time was 6h, and a tertiary amine containing a propylene oxide hydrophobic chain was obtained.

[0035] (2) Preparation of high temperature resistant clay stabilizer

[0036] The tertiary amine containing propylene oxide hydrophobic chain prepared in step (1) is reacted with benzyl bromide at a reaction temperature of 80° C., a ratio of the tertiary amine to benzyl chloride of 1:3, and a reaction time of 6 h to prepare a high temperature resistant clay stabilizer.

[0037] Example 3

[0038] (1) Preparation of tertiary amines containing propylene oxide hydrophobic chains

[0039] The molecular structure of the selected polyether alcohol is:

[0040]

[0041] Where m is 10.

[0042] A Ni / Al catalyst with a Ni content of 25% was selected, the dosage was 5%, the dialkylamine was dipropylamine, the amination reaction temperature was 185°C, the hydrogen partial pressure was 3.0 MPa, the reaction time was 3 h, and a tertiary amine containing a propylene oxide hydrophobic chain was obtained.

[0043] (2) Preparation of high temperature resistant clay stabilizer

[0044] The tertiary amine containing propylene oxide hydrophobic chain prepared in step (1) is reacted with benzyl chloride at a reaction temperature of 85° C., a ratio of the tertiary amine to the benzyl chloride of 1:2.3, and a reaction time of 3 h to prepare a high temperature resistant clay stabilizer.

[0045] Example 4

[0046] (1) Preparation of tertiary amines containing propylene oxide hydrophobic chains

[0047] The molecular structure of the selected polyether alcohol is:

[0048]

[0049] Where m is 2.

[0050] A Ni / Al catalyst with a Ni content of 35% was selected, the dosage was 0.5%, the dialkylamine was dibutylamine, the amination reaction temperature was 235°C, the hydrogen partial pressure was 3.5MPa, the reaction time was 5h, and a tertiary amine containing a propylene oxide hydrophobic chain was obtained.

[0051] (2) Preparation of high temperature resistant clay stabilizer

[0052] The tertiary amine containing propylene oxide hydrophobic chain prepared in step (1) is reacted with benzyl chloride at a reaction temperature of 90° C., a ratio of the tertiary amine to the benzyl chloride of 1:2.5, and a reaction time of 2 h to prepare a high temperature resistant clay stabilizer.

[0053] Example 5

[0054] (1) Preparation of tertiary amines containing propylene oxide hydrophobic chains

[0055] The molecular structure of the selected polyether alcohol is:

[0056]

[0057] Where m is 8.

[0058] A Ni / Al catalyst with a Ni content of 30% was selected in an amount of 4%, dimethylamine was selected as the dialkylamine, the amination reaction temperature was 225°C, the hydrogen partial pressure was 4.0 MPa, the reaction time was 4.5 h, and a tertiary amine containing a propylene oxide hydrophobic chain was obtained.

[0059] (2) Preparation of high temperature resistant clay stabilizer

[0060] The tertiary amine containing propylene oxide hydrophobic chain prepared in step (1) is reacted with benzyl chloride at a reaction temperature of 85° C., a ratio of the tertiary amine to the benzyl chloride of 1:2.2, and a reaction time of 4 h to prepare a high temperature resistant clay stabilizer.

[0061] Example 6

[0062] (1) Preparation of tertiary amines containing propylene oxide hydrophobic chains

[0063] The molecular structure of the selected polyether alcohol is:

[0064]

[0065] Where m is 4.

[0066] A Ni / Al catalyst with a Ni content of 35% was selected, the dosage was 2.5%, the dialkylamine was dimethylamine, the amination reaction temperature was 205°C, the hydrogen partial pressure was 4.0MPa, the reaction time was 3.5h, and a tertiary amine containing a propylene oxide hydrophobic chain was obtained.

[0067] (2) Preparation of high temperature resistant clay stabilizer

[0068] The tertiary amine containing propylene oxide hydrophobic chain prepared in step (1) is reacted with benzyl chloride at a reaction temperature of 85° C., a ratio of the tertiary amine to the benzyl chloride of 1:2.1, and a reaction time of 3.5 h to prepare a high temperature resistant clay stabilizer.

[0069] Example 7

[0070] (1) Preparation of tertiary amines containing propylene oxide hydrophobic chains

[0071] The molecular structure of the selected polyether alcohol is:

[0072]

[0073] Where m is 6.

[0074] A Ni / Al catalyst with a Ni content of 35% was selected, the dosage was 0.7%, the dialkylamine was dimethylamine, the amination reaction temperature was 195°C, the hydrogen partial pressure was 4.0MPa, the reaction time was 4h, and a tertiary amine containing a propylene oxide hydrophobic chain was obtained.

[0075] (2) Preparation of high temperature resistant clay stabilizer

[0076] The tertiary amine containing propylene oxide hydrophobic chain prepared in step (1) is reacted with benzyl chloride at a reaction temperature of 88° C., a ratio of the tertiary amine to the benzyl chloride of 1:2.2, and a reaction time of 4.5 h to prepare a high temperature resistant clay stabilizer.

[0077] Example 8

[0078] (1) Preparation of tertiary amines containing propylene oxide hydrophobic chains

[0079] The molecular structure of the selected polyether alcohol is:

[0080]

[0081] Where m is 3.

[0082] A Ni / Al catalyst with a Ni content of 30% was selected, the dosage was 0.8%, the dialkylamine was dimethylamine, the amination reaction temperature was 210°C, the hydrogen partial pressure was 4.0MPa, the reaction time was 4h, and a tertiary amine containing a propylene oxide hydrophobic chain was obtained.

[0083] (2) Preparation of high temperature resistant clay stabilizer

[0084] The tertiary amine containing propylene oxide hydrophobic chain prepared in step (1) is reacted with benzyl chloride at a reaction temperature of 83° C., a ratio of the tertiary amine to the benzyl chloride of 1:2.3, and a reaction time of 4 h to prepare a high temperature resistant clay stabilizer.

[0085] Comparative Example 1

[0086] The tertiary amine prepared in Example 4 was directly used as a clay stabilizer.

[0087] Comparative Example 2

[0088] The tertiary amine prepared in Example 4 was compounded with potassium chloride in a mass ratio of 6:1 and used as a clay stabilizer.

[0089] Comparative Example 3

[0090] The tertiary amine prepared in Example 4 was compounded with the commonly used cationic quaternary ammonium salt hexadecyltrimethylammonium chloride in a mass ratio of 2:1 and used as a clay stabilizer.

[0091] Comparative Example 4

[0092] The tertiary amine prepared in Example 4 was compounded with commonly used cationic quaternary ammonium salts, hexadecyltrimethylammonium chloride and potassium chloride, in a mass ratio of 6:3:1 and used as a clay stabilizer.

[0093] Test Example 1

[0094] According to the "SY / T5971-2016 Performance Evaluation Method of Clay Stabilizer for Water Injection", the anti-swelling rate test was carried out, and the steps are as follows: weigh 0.5g sodium bentonite, add it to a 10mL centrifuge tube, add deionized water to the 10mL mark, shake it well, let it stand at room temperature for 2h, put it into a centrifuge, centrifuge it at a speed of 1500r / min for 15min, and read the volume V2 of sodium bentonite in water. Use the same steps to replace the clean water with a certain concentration of clay stabilizer aqueous solution, and measure the volume V1 of the soil after centrifugation. Use kerosene instead of water to measure the volume V0 of the soil.

[0095]

[0096] Where: η—anti-swelling rate, %; V 0 —Volume of sodium bentonite in kerosene, mL; V 1 —Volume of sodium bentonite in clay stabilizer, mL; V 2 —Volume of sodium bentonite in clean water, mL.

[0097] Test Example 2

[0098] The anti-swelling rate test steps after aging at 300°C are as follows:

[0099] (1) Weigh 3.00 g of bentonite powder, accurate to 0.01 g, and load it into a high temperature and high pressure closed reactor;

[0100] (2) Add 60 mL of 4% clay stabilizer solution, shake well to mix, place in an oven at 300±2℃ for 24 hours, and cool to room temperature;

[0101] (3) Transfer all the clay mixture in the high-temperature and high-pressure closed reactor into a 100 mL beaker, shake it thoroughly, quickly take out 10 mL and add it to a glass centrifuge tube, put it into a centrifuge with automatic balancing function, centrifuge it at 1500r / min for 15 minutes, and read the expansion volume V1 of the bentonite. The anti-swelling rate calculation formula is as follows:

[0102]

[0103] Where: V 0 V is the expansion volume of bentonite in kerosene; 1 V is the expansion volume of bentonite in the clay stabilizer aqueous solution; 2 is the expansion volume of bentonite in clean water;

[0104] Test Example 3

[0105] The steps for testing washability are as follows:

[0106] The supernatant in the centrifuge tube after centrifugation in the above test example 2 was poured out, deionized water was added to 10 mL, and the mixture was stirred thoroughly and allowed to stand for 2 hours. The mixture was centrifuged at 1500 r / min for 15 minutes, and the final volume V of the bentonite in the centrifuge tube was finally read. 1’ .

[0107] Washability calculation formula:

[0108]

[0109] Where: V 1 is the swelling volume of bentonite in the clay stabilizer aqueous solution, mL;

[0110] V 1’ V is the expansion volume of bentonite after washing, mL; 2 is the expansion volume of bentonite in clean water, mL.

[0111] Test Example 4

[0112] The original core permeability K was tested by core displacement test. 0 Then, the core was saturated with simulated formation water, and then the clay stabilizer solution system was injected into the core tube at 300°C, and then high-temperature steam at 300°C was injected. Finally, the permeability K of the core after the experiment was tested. 1 , K 1 / K 0 This is the core permeability retention value.

[0113] Table 1 Sample evaluation results

[0114]

Claims

1. A high temperature resistant clay stabilizer for deep expansion prevention of heavy oil thermal recovery, characterized in that: The molecular structure of the high temperature resistant clay stabilizer contains propylene oxide hydrophobic chains, high temperature resistant benzene ring structures and ammonium ions that can be strongly adsorbed in the formation. The general structural formula is: , wherein m is 1-10; R is methyl, ethyl, propyl or butyl; and X is halogen.

2. The method for preparing the high temperature resistant clay stabilizer for deep anti-swelling of heavy oil thermal recovery according to claim 1, characterized in that The high temperature resistant clay stabilizer is prepared by reacting a tertiary amine containing a propylene oxide hydrophobic chain in its molecular structure with a halogenated benzene: the reaction temperature is 80-90°C, the reaction time is 2-6h, and the molar ratio of the tertiary amine to the halogenated benzene is 1:2-1:3; The molecular structure formula of the tertiary amine containing propylene oxide hydrophobic chain is: , wherein m is 1-10; R is methyl, ethyl, propyl or butyl.

3. The preparation method according to claim 2, characterized in that The molar ratio of the tertiary amine to the halogenated benzene is 1:2-1:2.

3.

4. The preparation method according to claim 2 or 3, characterized in that Halogenated benzene is chlorinated benzene.

5. The preparation method according to claim 2, characterized in that The tertiary amine containing propylene oxide hydrophobic chain is prepared by direct reaction of polyether alcohol with dialkylamine in the presence of catalyst and hydrogen. The molecular structure of the polyether alcohol is generally expressed as follows: , where m is 1-10.

6. The preparation method according to claim 5, characterized in that The reaction conditions of polyether alcohol and dialkylamine are as follows: catalyst dosage is 0.1-5%, reaction temperature is 185-245°C, hydrogen partial pressure is 2.5-4.5MPa, and reaction time is 3-6h.

7. The preparation method according to claim 6, characterized in that The amount of catalyst used in the reaction of polyether alcohol and dialkylamine is 0.5-1%.

8. The preparation method according to claim 5, characterized in that The catalyst used for the reaction of polyether alcohol and dialkylamine is Ni / Al catalyst, wherein the content of Ni is 25-40%.

9. The preparation method according to claim 5, characterized in that The dialkylamine is dimethylamine, diethylamine, dipropylamine, or dibutylamine.

10. The use of a high temperature resistant clay stabilizer for deep expansion prevention of heavy oil thermal recovery according to claim 1, characterized in that The high temperature resistant clay stabilizer has a temperature resistance of not less than 300°C and is used for heavy oil thermal recovery expansion control and expansion prevention.

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