High-temperature-resistant defoamer for oil field and preparation method and application thereof

Abstract

The application belongs to the technical field of oil exploitation, and particularly relates to a high-temperature-resistant defoaming agent for oil fields and a preparation method and application thereof. The preparation method is as follows: in a reactor, trimethylolpropane tris(3-aziridinyl propionate), ethanol and propylaminotri(trimethylsiloxy)silane are sequentially added, hydrochloric acid is used to adjust pH to 2-3, rapid stirring and heating to 60-70 DEG C are carried out, and then reaction is carried out under insulation; the above mixed solution is added into deionized water, the upper liquid is separated out, the upper liquid is heated to 90-100 DEG C, and then is placed for 24-48 h, the water phase is separated out by a separating funnel, and the oil phase is the product defoaming agent. The defoaming agent has the advantages of good defoaming effect and wide applicable temperature range, and the defoaming rate reaches 92% or above at a concentration of 10 mg / L.

Description

Technical Field

[0001] This invention belongs to the field of petroleum extraction technology, and specifically relates to a high-temperature resistant defoamer for oil fields, its preparation method, and its application. Background Technology

[0002] During crude oil extraction and processing, both temperature increases and pressure decreases disrupt its gas-liquid balance, causing dissolved light hydrocarbons to escape as gases. However, due to factors such as oil viscosity, space, and flow, these light hydrocarbons have difficulty escaping smoothly from the crude oil surface and instead form bubbles inside the crude oil, causing it to expand in volume and generate foam.

[0003] During oil and gas transportation, when crude oil undergoes gas-liquid separation in a separator, dissolved gases in the crude oil will escape due to the pressure reduction. At this time, the crude oil containing natural surfactants such as carboxylic acids, gums, asphaltenes, and waxes will produce a lot of foam. Some of the foam will remain stable in the crude oil for a long time without collapsing. These stable foams will adsorb tiny solid impurities, causing blockages. A large amount of foam can also cause cavitation in the pump, causing various harms to crude oil gathering and transportation.

[0004] To eliminate or reduce foam, defoamers are usually added during actual operations. The biggest advantage of this method is its high foam-breaking efficiency and ease of use. However, finding a suitable and efficient defoamer is the key.

[0005] CN107059474A discloses a high-grade fatty alcohol emulsion defoamer, composed of rice bran wax, wax, alkanes or vegetable oils, surfactants, thickeners, bactericides, and water. The rice bran wax is the active ingredient in the emulsion defoamer. The rice bran wax is primarily composed of higher fatty acids, higher fatty alcohols, and higher fatty alcohol esters, containing large amounts of hexadecyl alcohol, octadecyl alcohol, triacontyl alcohol, and their corresponding esters. High-grade fatty alcohol emulsions prepared using rice bran wax are suitable for foam control in various stages of pulping and papermaking, particularly in papermaking systems, especially in the wet end. However, the product's composition is too complex, requiring a high level of precision in the emulsification process and exhibiting significant viscosity variations, making it prone to forming a paste.

[0006] CN106943773A discloses a method for preparing a defoamer for medium-quality crude oil on offshore platforms. The process includes: Step 1: Preparation of a polyether intermediate, tetraethylenepentamine is bonded to ethylene oxide and propylene oxide to form a multi-branched polyether intermediate; Preparation process: potassium hydroxide is used as a catalyst, tetraethylenepentamine is vacuumed, purged with nitrogen, and then vacuumed again, and ethylene oxide is bonded at 120℃-135℃ and 0.2MPa-0.3MPa; then propylene oxide is bonded; Step 2: Synthesis of the polyether defoamer, the polyether intermediate and mixed fatty acids are mixed, potassium hydroxide is added as a catalyst, and the mixture is heated to 160℃-170℃ under stirring to start water extraction, and then the temperature is raised to 195℃-200℃ to prepare a multi-branched ester polyether defoamer. This invention has the advantages of simple process, reduced engineering investment, energy saving and consumption reduction, convenient production management, broad application prospects, and good economic and environmental benefits. However, the defoaming rate of this invention is only 90% after 10 minutes, and the defoaming effect is not ideal. Summary of the Invention

[0007] This invention addresses the shortcomings of the prior art by providing a high-temperature resistant defoamer for oilfields, its preparation method, and its application. The defoamer of this invention has the advantages of good defoaming effect and wide applicable temperature range.

[0008] One of the objectives of this invention is to disclose a method for preparing a high-temperature resistant defoamer for oilfield use, the specific steps of which are as follows:

[0009] (1) Trimethylolpropane tris(3-acrylidylpropionate), ethanol, and propylaminotris(trimethylsiloxy)silane were added sequentially to the reactor. The pH was adjusted to 2-3 with hydrochloric acid, and the mixture was stirred rapidly and heated to 60-70℃ for reaction.

[0010] (2) Add the mixture from step (1) to deionized water, separate the upper liquid, heat the upper liquid to 90-100℃, let it stand for 24-48h, separate the aqueous phase with a separatory funnel, and the oil phase is the product defoamer.

[0011] In this invention, preferably, based on 1 mole of trimethylolpropane tris(3-acrididinylpropionate), the amount of propylaminotris(trimethylsiloxy)silane is 2.5-3.5 moles; more preferably, based on 1 mole of trimethylolpropane tris(3-acrididinylpropionate), the amount of propylaminotris(trimethylsiloxy)silane is 2.6-3.2 moles.

[0012] In this invention, preferably, in step (1), the weight ratio of ethanol to trimethylolpropane tris(3-acrylidinylpropionate) is 20-30:1.

[0013] In this invention, preferably, in step (1), the heat preservation reaction time is 4-8 hours.

[0014] In this invention, preferably, in step (2), the weight ratio of deionized water to trimethylolpropane tris(3-acrylidinylpropionate) is 40-60:1.

[0015] The synthesis reaction equation for the high-temperature resistant defoamer for oilfield use in this invention is as follows:

[0016]

[0017] Another objective of this invention discloses a high-temperature resistant defoamer for oilfield use, the molecular structural formula of which is as follows:

[0018]

[0019] The third objective of this invention is to disclose the application of the above-mentioned defoamer in crude oil extraction and oil and gas transportation in oil fields.

[0020] The high-temperature resistant defoamer for oilfields of this invention is a silicon-containing surfactant with low surface tension, which accelerates molecular diffusion within foam. During diffusion, a double-layer film forms on the foam wall, displacing the stabilizing surfactant and reducing the local surface tension of the foam, thus disrupting its self-healing effect and causing it to burst. The polyamine structure enhances the defoaming effect of this invention, and its branched structure also strengthens the defoaming effect. This defoamer can function as a defoamer over a wide temperature range. It exhibits excellent defoaming performance, achieving a defoaming rate of 92% or higher at a concentration of 10 mg / L. Detailed Implementation

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0023] The present invention will be further described below with reference to specific embodiments.

[0024] In this invention, all the devices or equipment used are conventional devices or equipment known in the art and are readily available.

[0025] Unless otherwise specified, all reagents used in the following examples and comparative examples are commercially available chemically pure reagents.

[0026] Example 1

[0027] (1) Add 20 mmol of trimethylolpropane tris(3-acrylidylpropionate), 170 g of ethanol and 50 mmol of propylaminotris(trimethylsiloxy)silane to the reactor in sequence, adjust the pH to 2-3 with hydrochloric acid, stir rapidly and heat to 60 °C, and keep the reaction at this temperature for 4 h.

[0028] (2) Add 340g of deionized water to the mixture in step (1), separate the upper liquid, heat the upper liquid to 95°C, let it stand for 24 hours, separate the aqueous phase with a separatory funnel, and the oil phase is the product defoamer.

[0029] Example 2

[0030] (1) Add 20 mmol of trimethylolpropane tris(3-acrylidylpropionate), 255 g of ethanol and 70 mmol of propylaminotris(trimethylsiloxy)silane to the reactor in sequence, adjust the pH to 2-3 with hydrochloric acid, stir rapidly and heat to 60°C, and keep the reaction at this temperature for 5 h.

[0031] (2) Add 511g of deionized water to the mixture in step (1), separate the upper liquid, heat the upper liquid to 90°C, let it stand for 24 hours, separate the aqueous phase with a separatory funnel, and the oil phase is the product defoamer.

[0032] Example 3

[0033] (1) Add 20 mmol of trimethylolpropane tris(3-acrylidylpropionate), 185 g of ethanol and 52 mmol of propylaminotris(trimethylsiloxy)silane to the reactor in sequence, adjust the pH to 2-3 with hydrochloric acid, stir rapidly and heat to 63°C, and keep the reaction at this temperature for 6 h.

[0034] (2) Add 370g of deionized water to the mixture in step (1), separate the upper liquid, heat the upper liquid to 93°C, let it stand for 32h, separate the aqueous phase with a separatory funnel, and the oil phase is the product defoamer.

[0035] Example 4

[0036] (1) Add 20 mmol of trimethylolpropane tris(3-acrylidylpropionate), 210 g of ethanol and 66 mmol of propylaminotris(trimethylsiloxy)silane to the reactor in sequence, adjust the pH to 2-3 with hydrochloric acid, stir rapidly and heat to 60 °C, and keep the reaction at this temperature for 7 h.

[0037] (2) Add 420g of deionized water to the mixture in step (1), separate the upper liquid, heat the upper liquid to 90°C, let it stand for 28 hours, separate the aqueous phase with a separatory funnel, and the oil phase is the product defoamer.

[0038] Example 5

[0039] (1) Add 20 mmol of trimethylolpropane tris(3-acrylidylpropionate), 250 g of ethanol and 64 mmol of propylaminotris(trimethylsiloxy)silane to the reactor in sequence, adjust the pH to 2-3 with hydrochloric acid, stir rapidly and heat to 68 °C, and keep the reaction at this temperature for 8 h.

[0040] (2) Add 500g of deionized water to the mixture in step (1), separate the upper liquid, heat the upper liquid to 95°C, let it stand for 36h, separate the aqueous phase with a separatory funnel, and the oil phase is the product defoamer.

[0041] Example 6

[0042] (1) Add 20 mmol of trimethylolpropane tris(3-acrylidylpropionate), 240 g of ethanol and 55 mmol of propylaminotris(trimethylsiloxy)silane to the reactor in sequence, adjust the pH to 2-3 with hydrochloric acid, stir rapidly and heat to 68°C, and keep the reaction at this temperature for 8 h.

[0043] (2) Add 480g of deionized water to the mixture in step (1), separate the upper liquid, heat the upper liquid to 95°C, let it stand for 48h, separate the aqueous phase with a separatory funnel, and the oil phase is the product defoamer.

[0044] Example 7

[0045] (1) Add 20 mmol of trimethylolpropane tris(3-acrylidylpropionate), 240 g of ethanol and 60 mmol of propylaminotris(trimethylsiloxy)silane to the reactor in sequence, adjust the pH to 2-3 with hydrochloric acid, stir rapidly and heat to 70 °C, and keep the reaction at this temperature for 8 h.

[0046] (2) Add 480g of deionized water to the mixture in step (1), separate the upper liquid, heat the upper liquid to 100℃, let it stand for 42h, separate the aqueous phase with a separatory funnel, and the oil phase is the product defoamer.

[0047] Example 8

[0048] The defoaming effect of the defoamer of the present invention (Examples 1-7) was tested, and the test method referred to Q / SHCG 46—2012 "Technical Requirements for Crude Oil Defoamers".

[0049] Oil-water samples without defoamer were taken from the crude oil gathering and transportation pipeline at a joint station in Linpan, Shengli Oilfield. The temperature of the oil-water samples was 42℃. The samples were left to stand to drain the water from the bottom.

[0050] The defoamer of the present invention (Examples 1-7) was prepared into a 1.0 wt% solution with kerosene and stirred evenly.

[0051] Add 400 ml of oil sample to a 500 ml graduated cylinder, insert a glass rod, and record the oil sample volume V1. Quickly add 0.4 ml of 1.0 wt% crude oil defoamer using a syringe, and immediately stir rapidly with a glass rod at a speed of no less than 120 rpm. After stirring for 2 minutes, observe and record the crude oil volume V2.

[0052] Add 1 ml of 1.0 wt% crude oil defoamer to the above sample, place it in a 60°C water bath for 30 min, and stir rapidly with a glass rod until all the crude oil foam disappears. Read the volume of the foam-free crude oil after stirring, V3.

[0053] Defoaming rate calculation formula:

[0054] X = (V1 - V2) / (V1 - V3) × 100%

[0055] A comparative experiment was conducted using crude oil defoamer from Guangdong Zhongke Hongtai New Materials Co., Ltd.

[0056] The experimental results are shown in Table 1.

[0057] Table 1. Defoaming test results of defoaming agents

[0058] Example 1 95 Example 2 92 Example 3 94 Example 4 96 Example 5 95 Example 6 98 Example 7 97 Comparison Samples 83

[0059] As can be seen from Table 1:

[0060] The defoaming agents of the present invention (Examples 1-7) all achieved a defoaming rate of 92% or higher when used at a concentration of 10 mg / L, with the highest reaching 98% (Example 6); while the defoaming rate of the crude oil defoaming agent of the comparative example, Guangdong Zhongke Hongtai New Materials Co., Ltd., was 83%, which was significantly lower than that of the present invention.

[0061] The above description is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the concept of the invention or exceed the scope defined in the claims, they should all fall within the protection scope of the present invention.

Claims

1. A method for preparing a high-temperature resistant defoamer for oilfield use, characterized in that, The specific steps of the preparation method are as follows: (1) Trimethylolpropane tris(3-acrylidylpropionate), ethanol, and propylaminotris(trimethylsiloxy)silane were added sequentially to the reactor. The pH was adjusted to 2-3 with hydrochloric acid, and the mixture was stirred rapidly and heated to 60-70℃ for reaction. (2) Add the mixture in step (1) to deionized water, separate the upper liquid, heat the upper liquid to 90-100℃, let it stand for 24-48h, separate the aqueous phase with a separatory funnel, and the oil phase is the product defoamer. Based on 1 mole of trimethylolpropane tris(3-acrylidinylpropionate), the amount of propylaminotris(trimethylsiloxy)silane used is 2.5-3.5 moles. The molecular structure of the defoamer is as follows:

2. The preparation method according to claim 1, characterized in that, Based on 1 mole of trimethylolpropane tris(3-acrylidinylpropionate), the amount of propylaminotris(trimethylsiloxy)silane used is 2.6-3.2 moles.

3. The preparation method according to claim 1, characterized in that, In step (1), the weight ratio of ethanol to trimethylolpropane tris(3-acrylidinylpropionate) is 20-30:

1.

4. The preparation method according to claim 1, characterized in that, In step (1), the heat preservation reaction time is 4-8 hours.

5. The preparation method according to claim 1, characterized in that, In step (2), the weight ratio of deionized water to trimethylolpropane tris(3-acrylidinylpropionate) is 40-60:

1.

6. The defoamer prepared by the preparation method according to any one of claims 1-5, characterized in that, The molecular structure of the defoamer is as follows:

7. The application of the defoamer according to claim 6 in crude oil extraction and oil and gas transportation in oil fields.

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