A crude oil low-temperature dehydration demulsifier as well as preparation and application thereof

Abstract

The application discloses a crude oil low-temperature dehydration demulsifier as well as a preparation and application thereof. The crude oil low-temperature dehydration demulsifier is prepared by cross-linking reaction of an alcohol starting agent demulsifier and a benzene-containing cross-linking agent under the catalysis of a catalyst and heating. The demulsifier prepared by the application has good low-temperature performance, the star-shaped structure design improves the capture capacity of the demulsifier on dispersed water drops and the depth of demulsification and dehydration, and the demulsification process is faster and more thorough.

Description

TECHNICAL FIELD

[0001] The present application relates to a crude oil low-temperature dehydration demulsifier and its preparation and application. BACKGROUND

[0002] In order to meet the needs of different properties of produced liquid and processing technology, there are many kinds of demulsifiers, most of which are copolymers of ethylene oxide and propylene oxide with a certain chemical agent as a starting agent. The demulsifiers currently used mainly include: copolymers of ethylene oxide and propylene oxide prepared by using polyamine, alcohol, alkyl phenol formaldehyde resin, phenol amine resin and silicon-containing starting agent. In addition, the above-mentioned demulsifiers are cross-linked or modified by using adipic acid, diisocyanate, etc. to obtain demulsifiers with larger molecular weight.

[0003] The above-mentioned traditional demulsifiers have poor low-temperature demulsification performance, require high dehydration temperature, and have large dosage. However, after entering the medium-high water cut production period, the dehydration process has high energy consumption and the quality of the separated water is poor. SUMMARY

[0004] In view of the defects of the prior art, the present application provides a crude oil low-temperature dehydration demulsifier to at least partially solve the problems existing in the prior art.

[0005] In a first aspect, the present application provides a crude oil low-temperature dehydration demulsifier, which has the following structural formula:

[0006]

[0007] wherein R is an alkyl group with a carbon atom number of 3-22, m=10-25, and n=10-25.

[0008] In one or some optional embodiments, the demulsifier is prepared by cross-linking reaction of an alcohol starting agent demulsifier and a benzene-containing cross-linking agent under the catalytic heating condition of a catalyst.

[0009] In one or some optional embodiments, the benzene-containing cross-linking agent is trimesic acid.

[0010] In one or some optional embodiments, the alcohol starting agent demulsifier has the following structural formula: R—(C3H6O) m (C2H4O) n H, wherein R is an alkyl group with a carbon atom number of 3-22, m=10-25, and n=10-25.

[0011] In one or some optional embodiments, the solvent of the alcohol starting agent demulsifier and the benzene-containing cross-linking agent is xylene.

[0012] In one or some optional embodiments, the catalyst is p-toluene sulfonic acid.

[0013] In one or some optional embodiments, the temperature of the cross-linking reaction is 150-165 DEG C.

[0014] In a second aspect, the present application further provides a method for preparing the crude oil low-temperature dehydration demulsifier, the method comprising:

[0015] Trimesic acid, dimethylbenzene and p-toluene sulfonic acid are added into a reaction kettle, and the temperature is raised to 50-60 DEG C.

[0016] Vacuum is extracted to a first pressure, and then nitrogen is filled to a second pressure, and the vacuum extraction and nitrogen filling are repeated three times;

[0017] The vacuum extraction is repeated to the first pressure, and the temperature is continuously raised to 150 DEG C, and the temperature is kept constant;

[0018] The alcohol initiator demulsifier is added dropwise into the reaction kettle, the dropwise adding time is controlled, and the cross-linking reaction is carried out at 150-165 DEG C until no water is generated and dimethylbenzene is evaporated;

[0019] The temperature is lowered to 70-75 DEG C, and the crude oil low-temperature dehydration demulsifier is obtained.

[0020] In one or some optional embodiments, the mass ratio of the alcohol initiator demulsifier, trimesic acid, p-toluene sulfonic acid and dimethylbenzene is 1:0.05-0.15:0.01-0.05:0.15-0.30.

[0021] In one or some optional embodiments, the first pressure is 0.1 MPa, and the second pressure is 0.05 MPa.

[0022] In one or some optional embodiments, the dropwise adding time is 4-5 h.

[0023] In a third aspect, the present application further provides an application of the crude oil low-temperature dehydration demulsifier in oilfield ground gathering and transportation treatment.

[0024] The demulsifier provided by the present application introduces a benzene-containing cross-linking agent, the benzene ring structure is introduced, the compatibility between the demulsifier and main substances such as colloid and asphalt in the crude oil which have emulsifying effect is improved, the demulsifier is endowed with good low-temperature performance; meanwhile, the diffusion speed of the demulsifier in the crude oil and the displacement effect of the demulsifier on the emulsified substances enriched on the oil-water interface film are improved, and the purpose of rapid demulsification is achieved.

[0025] The demulsifier provided by this invention, through cross-linking during preparation, achieves a relatively complete star-shaped molecular structure, increasing the spatial volume of the demulsifier molecule, improving its ability to capture dispersed water droplets and the depth of demulsification and dehydration, and effectively reducing the amount of demulsifier used. Furthermore, the benzene ring, located at the center of the star structure, increases the number of hydrophilic and lipophilic groups in the demulsifier, significantly reducing the regularity of the new oil-water interface film formed by replacing asphaltenes in crude oil. This, in turn, reduces the stabilizing effect of the interface film, allowing the demulsification process to proceed faster and more thoroughly.

[0026] The demulsifier provided by this invention has a multi-block structure, which makes it more applicable to crude oils with different properties and has better broad-spectrum performance. Detailed Implementation

[0027] The following provides a detailed description of the embodiments of the present invention: These embodiments are implemented based on the technical solution of the present invention, and provide detailed implementation methods and processes. However, the scope of protection of the present invention is not limited to the following embodiments. Process parameters not specified in the following embodiments are generally performed under conventional conditions.

[0028] The endpoints and any values ​​of the ranges disclosed in this invention 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 in this invention.

[0029] This invention provides a crude oil low-temperature dehydration demulsifier, the demulsifier having the following structural formula:

[0030]

[0031] Wherein, R is an alkyl group with 3 to 22 carbon atoms, m = 10 to 25, and n = 10 to 25.

[0032] Optionally, the demulsifier is prepared by crosslinking an alcohol-based initiator demulsifier and a benzene-containing crosslinking agent under catalytic heating conditions.

[0033] Optionally, the benzene-containing crosslinking agent used in the embodiments of the present invention can be pyromellitic acid.

[0034] Optionally, the alcohol-based initiator demulsifier used in the embodiments of the present invention has the following structural formula: R—(C3H6O) m (C2H4O) n H, where R is an alkyl group with 3 to 22 carbon atoms, m = 10 to 25, and n = 10 to 25.

[0035] In specific embodiments, the alcohol initiator demulsifier can be BP169, GP169, SP169, etc.

[0036] Optionally, the alcohol initiator demulsifier and the solvent containing benzene crosslinking agent are xylene.

[0037] Optionally, the catalyst is p-toluene sulfonic acid.

[0038] Optionally, the temperature of the crosslinking reaction is 150-165℃.

[0039] The present application also provides a method for preparing the above-mentioned crude oil low-temperature dehydration demulsifier, which comprises:

[0040] Adding trimellitic acid, xylene and p-toluene sulfonic acid into a reaction kettle, and heating to 50-60℃;

[0041] Vacuumizing to a first pressure, and then filling nitrogen to a second pressure, repeating vacuumizing and filling nitrogen three times;

[0042] Vacuumizing to the first pressure again, and continuing to heat to 150℃, and keeping the temperature constant;

[0043] Adding the alcohol initiator demulsifier into the reaction kettle dropwise, controlling the dropwise adding time, and performing crosslinking reaction at 150-165℃ until no water is generated and xylene is evaporated;

[0044] Cooling to 70-75℃ to obtain the crude oil low-temperature dehydration demulsifier.

[0045] Optionally, the mass ratio of the alcohol initiator demulsifier, trimellitic acid, p-toluene sulfonic acid and xylene is 1:0.05-0.15:0.01-0.05:0.15-0.30.

[0046] Optionally, the first pressure is 0.1 MPa, and the second pressure is 0.05 MPa.

[0047] Optionally, the dropwise adding time is 4-5 h.

[0048] The main reactions in the process of preparing the above-mentioned crude oil low-temperature dehydration demulsifier are as follows:

[0049]

[0050] The following will describe various specific embodiments of a crude oil low-temperature dehydration demulsifier provided by the present application in detail.

[0051] Example 1

[0052] Preparation of the demulsifier:

[0053] Put 16 g of xylene, 3 g of benzene-1, 3, 5-tricarboxylic acid and 1.5 g of p-toluenesulfonic acid into a reaction kettle, and heat to 55℃;

[0054] Vacuumize to 0.1 MPa, then fill with nitrogen to 0.05 MPa, repeat the operation 3 times;

[0055] Vacuumize to 0.1 MPa again, slowly heat to 150℃, and keep the temperature for 15 min;

[0056] Add the BP169 demulsifier into the reaction kettle at a speed of 0.35 g / min, a total of 100 g, control the reaction temperature at 160-165℃ during the adding, remove the water generated in the reaction from the reaction system in time, and remove the water in time; after the adding of the demulsifier is completed, continue to control the temperature at 150-165℃ for 1.5 h, until no water is generated in the reaction and xylene is not evaporated, and the reaction is completed;

[0057] Cool to 70-75℃, and discharge to obtain the demulsifier I.

[0058] The BP169 demulsifier and the demulsifier I prepared in the example of the application are used for low-temperature dehydration of a paraffin-based crude oil of China Petroleum, the basic properties of the paraffin-based crude oil are shown in Table 1, and the low-temperature dehydration effects of the BP169 demulsifier and the demulsifier I on the paraffin-based crude oil are shown in Table 2.

[0059] Table 1 Basic properties of crude oil

[0060] Item Congealing point ℃ Density g / cm 3 ]] Asphaltene % Wax content % Colloid % Data 36 0.8421 0.376 14.6 33.3

[0061] Table 2 Dehydration effect comparison

[0062] Demulsifier Minimum dewatering temperature Dewatering qualified time Water content in crude oil after 1 h dewatering BP169 55℃ >8h >8％ Demulsifier I 40℃ 1.5h <0.5％ Effect Decrease by 15 ℃ Decrease by more than 6.5 h Decrease by more than 7.5%

[0063] Dehydration condition: the dosage is 100 mg / L.

[0064] As shown in Table 2, the demulsifier I prepared by crosslinking the BP169 demulsifier with benzene-1, 3, 5-tricarboxylic acid as a crosslinking agent has a greater improvement in the dehydration effect on the crude oil than the BP169 demulsifier under the same conditions, and the dehydration temperature is reduced by 15℃.

[0065] Example 2

[0066] Prepare the demulsifier:

[0067] Put 20 g of xylene, 5.1 g of benzene-1, 3, 5-tricarboxylic acid and 2 g of p-toluenesulfonic acid into a reaction kettle, and heat to 55℃;

[0068] Vacuumize to 0.1 MPa, then fill with nitrogen to 0.05 MPa, repeat the operation 3 times;

[0069] Vacuumize again to 0.1 MPa, slowly warm up to 150℃, and keep constant temperature for 15 min;

[0070] Add SP169 demulsifier into the reactor at a speed of 0.35 g / min, totally 100 g, control the reaction temperature at 160-165℃ during the adding, and let the generated water out of the system in time, and separate the water out in time; after the adding of the demulsifier is completed, continue to control the temperature at 155-165℃ for 1.5 h, until no water is generated and xylene is out, and the reaction is completed;

[0071] Cool down to 70-75℃, and discharge the product, to obtain demulsifier II.

[0072] Use the SP169 demulsifier and the demulsifier II prepared in the example of the application to carry out low-temperature dehydration of Sudanese crude oil, the basic properties of which are shown in Table 3, and the low-temperature dehydration effects of the SP169 demulsifier and the demulsifier II on the crude oil are shown in Table 4.

[0073] Table 3 Basic properties of crude oil

[0074]

[0075] Table 4 Dehydration effect comparison

[0076] Demulsifier Dewatering temperature Intermediate layer Dewatering rate under the same conditions SP169 78℃ >15％ 75％ Demulsifier II 65℃ ≤0.2％ >98％ Effect Decrease by 13 ℃ Increase by more than 99% Increase by more than 20%

[0077] Dehydration condition: the dosage is 50 mg / L.

[0078] As shown in Table 4, the demulsifier II prepared by crosslinking the SP169 demulsifier with trimesic acid as the crosslinking agent has a greater improvement in the dehydration effect on the crude oil than the SP169 demulsifier under the same conditions, and the dehydration temperature is reduced by 13℃.

[0079] Example 3

[0080] Prepare the demulsifier:

[0081] Add 19 g of xylene, 5.2 g of trimesic acid, and 1.6 g of p-toluenesulfonic acid into the reactor, and warm up to 55℃;

[0082] Vacuumize to 0.1 MPa, then fill nitrogen to 0.05 MPa, repeat the operation for 3 times;

[0083] Vacuumize again to 0.1 MPa, slowly warm up to 150℃, and keep constant temperature for 15 min;

[0084] The GP169 demulsifier is added into the reaction kettle at a speed of 0.35 g / min, totally 100 g, the reaction temperature is controlled at 160-163 DEG C during the adding process, the dimethylbenzene is normally refluxed, the reaction water is taken away from the reaction system in time, and the water is separated in time; after the adding of the demulsifier is completed, the temperature is controlled at 155-165 DEG C for 1.5 h, until no reaction water is generated and the dimethylbenzene is not evaporated, the reaction is completed;

[0085] The temperature is lowered to 70-75 DEG C, the product is discharged, and the demulsifier III is obtained.

[0086] The demulsifier III prepared by the same product Champion, Clairent and the embodiment of the application is used for low-temperature dehydration of a certain crude oil in Iraq, the basic properties of the crude oil are shown in Table 5, and the low-temperature dehydration effects of the demulsifier III and the same products Champion and Clairent on the crude oil are shown in Table 6.

[0087] Table 5 Basic properties of the crude oil

[0088]

[0089] Table 6 Dehydration effect comparison

[0090]

[0091] Dehydration condition: the dosage is 100 mg / L; the dehydration temperature is 85 DEG C.

[0092] As shown in Table 6, the demulsifier III prepared by crosslinking the GP169 demulsifier by using trimesic acid as a crosslinking agent has a larger dehydration effect on the crude oil than the same products under the same conditions, and the quality of the separated water is better.

[0093] Although the specific embodiments of the application have been described in detail, those skilled in the art will understand that various modifications and substitutions can be made to the details based on all the teachings disclosed, and the changes are within the protection scope of the application. The whole scope of the application is given by the appended claims and any equivalents thereof.

Claims

1. A crude oil low-temperature dehydration demulsifier, characterized in that, The demulsifier has the following structural formula: ， Wherein, R is an alkyl group with 3 to 22 carbon atoms, m = 10 to 25, and n = 10 to 25.

2. A method for preparing the crude oil low-temperature dehydration demulsifier according to claim 1, characterized in that, The method includes: Add pyromellitic acid, xylene and p-toluenesulfonic acid to the reaction vessel and heat to 50~60℃; Evacuate to the first pressure, then fill with nitrogen to the second pressure, and repeat the evacuation and nitrogen filling process three times. Evacuate to the first pressure, then continue heating to 150℃ and maintain the temperature. Add alcohol-based initiators and demulsifiers dropwise into the reactor, controlling the dropwise addition time, and carry out the cross-linking reaction at 150~165℃ until no water is produced and xylene is distilled off. The temperature is lowered to 70~75℃ to obtain the crude oil low-temperature dehydration demulsifier.

3. The method as described in claim 2, characterized in that, The mass ratio of the alcohol initiator, demulsifier, trimesic acid, p-toluenesulfonic acid, and xylene is 1:0.05~0.15:0.01~0.05:0.15~0.

30.

4. The method as described in claim 2, characterized in that, The first pressure is 0.1 MPa, and the second pressure is 0.05 MPa.

5. The method as described in claim 2, characterized in that, The dripping time is 4-5 hours.

6. The application of the crude oil low-temperature dehydration demulsifier according to claim 1 in oilfield surface gathering and transportation processing.

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