High-temperature-resistant defoaming agent for oil field as well as preparation method and application of high-temperature-resistant defoaming agent

Abstract

The invention belongs to the technical field of oil exploitation, and particularly relates to a high-temperature-resistant defoaming agent for an oil field as well as a preparation method and application thereof. The preparation method comprises the following steps: sequentially adding trimethylolpropane tri (3-aziridinyl propionate), ethanol and propylamino tri (trimethylsiloxy) silane into a reactor, adjusting the pH value to 2-3 by using hydrochloric acid, quickly stirring, heating to 60-70 DEG C, and carrying out heat preservation reaction; and adding deionized water into the mixed solution, separating out supernatant liquid, heating the supernatant liquid to 90-100 DEG C, standing for 24-48 hours, and separating out a water phase and an oil phase which are the product defoaming agent by a separating funnel. The defoaming agent has the advantages of being good in defoaming effect and wide in applicable temperature range, and the defoaming rate reaches 92% or above when the concentration is 10 mg / L.

Description

Technical Field

[0001] The invention belongs to the technical field of oil extraction, and particularly relates to a high temperature resistant defoaming agent for oil fields and a preparation method and application thereof. Background Art

[0002] During the extraction and processing of crude oil, the increase in temperature and the decrease in pressure will destroy its gas-liquid balance, causing the light hydrocarbons dissolved in the crude oil to escape as gas. However, due to factors such as oil phase viscosity, space, and flow, it is difficult for light hydrocarbons to escape smoothly from the surface of the crude oil, and bubbles will form inside the crude oil, causing the volume of the crude oil to expand and generate foam.

[0003] During the oil and gas transportation process, when the crude oil is separated into gas and liquid in the separator, the gas dissolved in the crude oil will escape due to the reduction in pressure. At this time, the crude oil containing natural surfactants such as carboxylic acids, colloids, asphaltene and wax will produce a lot of foam. Some foams will exist stably in the crude oil for a long time without bursting. At this time, these stable foams will absorb tiny impurity solids and cause blockage. A large amount of foam will also cause cavitation in the pump, causing many harms to crude oil gathering and transportation.

[0004] In order to eliminate or reduce foam, defoaming agents are generally added during actual operations. The biggest advantages of this method are high foam breaking efficiency and ease of use, but finding a suitable and efficient defoaming agent is the key.

[0005] CN107059474A A kind of high-grade fatty alcohol emulsion defoamer, is composed of rice bran wax, wax, alkane or vegetable oil, surfactant, thickener, bactericide, water, and the rice bran wax is the active ingredient of the emulsion defoamer. Rice bran wax is mainly composed of high-grade fatty acid, high-grade fatty alcohol and high-grade fatty alcohol ester, wherein it contains a large amount of hexacosanol, octacosanol, triacontanol and its corresponding alcohol ester. The high-grade fatty alcohol emulsion prepared by rice bran wax is suitable for foam control in each section of pulping and papermaking, and is particularly suitable for papermaking system, especially foam control in papermaking wet section. However, the composition of this product is too complicated, and the emulsification process is required to be high and the viscosity changes greatly, and the phenomenon of paste formation occurs easily.

[0006] CN106943773A discloses a method for preparing a medium crude oil defoamer for an offshore platform. The process includes: step 1: preparation of a polyether intermediate, tetraethylene pentamine connected with ethylene oxide and propylene oxide to prepare a polyether intermediate with a multi-branched core; preparation process: potassium hydroxide is used as a catalyst, tetraethylene pentamine is vacuumed, nitrogen is replaced, and then vacuumed, and ethylene oxide is connected under the conditions of 120℃-135℃ and 0.2MPa-0.3MPa; and then propylene oxide is connected; step 2: synthesizing a polyether defoamer, a polyether intermediate and a mixed fatty acid, adding a catalyst potassium hydroxide, heating to 160℃-170℃ under stirring to start water discharge, and then heating to 195℃-200℃ to prepare a multi-branched ester polyether defoamer. The 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 the invention in 10 minutes is only 90%, and the defoaming effect is not ideal. Summary of the invention

[0007] In view of the deficiencies of the above-mentioned prior art, the present invention provides a high temperature resistant defoaming agent for oil fields and a preparation method and application thereof. The defoaming agent of the present invention has the advantages of good defoaming effect and wide applicable temperature range.

[0008] One of the purposes of the present invention is to disclose a method for preparing a high temperature resistant defoaming agent for oil fields, and the specific steps are as follows:

[0009] (1) adding trimethylolpropane tris(3-aziridinyl propionate), ethanol, and propylaminotris(trimethylsiloxy)silane into a reactor in sequence, adjusting the pH to 2-3 with hydrochloric acid, rapidly stirring, and heating to 60-70° C. for reaction;

[0010] (2) Add deionized water to the mixed solution in step (1), separate the upper liquid, heat the upper liquid to 90-100° C., let it stand for 24-48 hours, and separate the water phase with a separatory funnel. The oil phase is the product defoamer.

[0011] In the present invention, preferably, based on 1 mol part of trimethylolpropane tris(3-aziridinyl propionate), the amount of propylaminotris(trimethylsiloxy)silane is 2.5-3.5 mol parts respectively; more preferably, based on 1 mol part of trimethylolpropane tris(3-aziridinyl propionate), the amount of propylaminotris(trimethylsiloxy)silane is 2.6-3.2 mol parts respectively.

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

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

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

[0015] The synthetic reaction equation of the high temperature resistant defoamer for oil field of the present invention is as follows:

[0016]

[0017] Another object of the present invention is to disclose a high temperature resistant defoamer for oil fields, the molecular structure of the high temperature resistant defoamer for oil fields is as follows:

[0018]

[0019] The third object of the present invention is to disclose the application of the above defoaming agent in oil field crude oil production and oil and gas transportation.

[0020] The high temperature resistant defoamer for oil field of the present invention is a silicon-containing surfactant with low surface tension, which can accelerate the diffusion of molecules in foam and form a double-layer membrane on the foam wall during diffusion. During the diffusion process, the surfactant that plays a stabilizing role is displaced, thereby reducing the local surface tension of the foam, destroying the self-healing effect of the foam and causing the foam to burst. The polyamine structure can enhance the defoaming effect of the present invention, and the structure itself is multi-branched, which can also enhance the defoaming effect of the present invention. The defoamer of the present invention can act as a defoamer in a wide temperature range. The defoamer of the present invention has good defoaming function, and the defoaming rate of a concentration of 10 mg / L reaches 92% or more. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] The endpoints and any values ​​of the ranges disclosed in this article 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 each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

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

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

[0025] In the following examples and comparative examples, unless otherwise specified, all reagents used were commercially available chemically pure reagents.

[0026] Example 1

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

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

[0029] Example 2

[0030] (1) Add 20 mmol of trimethylolpropane tris(3-aziridinyl propionate), 255 g of ethanol, and 70 mmol of propylaminotris(trimethylsiloxy)silane into a reactor in sequence, adjust the pH to 2-3 with hydrochloric acid, stir rapidly and heat to 60°C, and keep the reaction warm for 5 hours;

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

[0032] Example 3

[0033] (1) Add 20 mmol of trimethylolpropane tris(3-aziridinyl propionate), 185 g of ethanol, and 52 mmol of propylaminotris(trimethylsiloxy)silane into a reactor in sequence, adjust the pH to 2-3 with hydrochloric acid, stir rapidly and heat to 63°C, and keep the reaction warm for 6 hours;

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

[0035] Example 4

[0036] (1) Add 20 mmol of trimethylolpropane tris(3-aziridinyl propionate), 210 g of ethanol, and 66 mmol of propylaminotris(trimethylsiloxy)silane into a reactor in sequence, adjust the pH to 2-3 with hydrochloric acid, stir rapidly and heat to 60°C, and keep the reaction warm for 7 hours;

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

[0038] Example 5

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

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

[0041] Example 6

[0042] (1) Add 20 mmol of trimethylolpropane tris(3-aziridinyl propionate), 240 g of ethanol, and 55 mmol of propylaminotris(trimethylsiloxy)silane into a reactor in sequence, adjust the pH to 2-3 with hydrochloric acid, stir rapidly and heat to 68°C, and keep the reaction warm for 8 hours;

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

[0044] Example 7

[0045] (1) Add 20 mmol of trimethylolpropane tris(3-aziridinyl propionate), 240 g of ethanol, and 60 mmol of propylaminotris(trimethylsiloxy)silane into a reactor in sequence, adjust the pH to 2-3 with hydrochloric acid, stir rapidly and heat to 70°C, and keep the reaction warm for 8 hours;

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

[0047] Example 8

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

[0049] At the crude oil gathering pipeline of a joint station in Linpan, Shengli Oilfield, an oil-water sample without adding a defoaming agent was taken. The temperature of the oil-water sample was 42°C, and the water in the lower part was released while standing.

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

[0051] Add 400ml of oil sample to a 500ml measuring cylinder, put in a glass rod, and record the volume V of the oil sample. 1 Quickly add 0.4 ml of 1.0 wt% crude oil defoamer with a syringe, and immediately stir quickly with a glass rod at a speed of not less than 120 rpm. After stirring for 2 minutes, observe and record the crude oil volume V 2 .

[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 it quickly with a glass rod until all the crude oil foam disappears. Read the volume of crude oil without foam after stirring (V) 3 .

[0053] Defoaming rate calculation formula:

[0054] X=(V 1 -V 2 ) / (V 1 -V 3 )×100%

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

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

[0057] Table 1 Defoaming agent defoaming test results

[0058] Defoaming agent Defoaming rate, % Example 1 95 Example 2 92 Example 3 94 Example 4 96 Example 5 95 Example 6 98 Example 7 97 Comparative samples 83

[0059] From Table 1 we can see that:

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

[0061] The above contents are merely examples and explanations of the concept of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A method for preparing a high temperature resistant defoaming agent for oil fields, characterized in that: The specific steps of the preparation method are as follows: (1) adding trimethylolpropane tris(3-aziridinyl propionate), ethanol, and propylaminotris(trimethylsiloxy)silane into a reactor in sequence, adjusting the pH to 2-3 with hydrochloric acid, rapidly stirring, and heating to 60-70° C. for reaction; (2) adding deionized water to the mixed solution in step (1), separating the upper layer of liquid, heating the upper layer of liquid to 90-100° C., standing for 24-48 hours, and separating the water phase with a separatory funnel. The oil phase is the product defoamer; Based on 1 mole part of trimethylolpropane tris(3-aziridinyl propionate), the amount of propylaminotris(trimethylsiloxy)silane is 2.5-3.5 mole parts respectively; The molecular structural formula of the defoamer is as follows:

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

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

1.

4. The preparation method according to claim 1, characterized in that: In step (1), the insulation reaction time is 4-8h.

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

1.

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

7. Use of the defoaming agent according to claim 6 in oil field crude oil production and oil and gas transportation.

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