A catalytic viscosity reducer composition for thick oil and its preparation method and application

Abstract

The application belongs to the technical field of tertiary oil recovery, and relates to a chemical viscosity reducer, in particular to a heavy oil catalytic viscosity reducer composition, a preparation method and application thereof.The composition and mass components are as follows: a Schiff base-nickel complex, 30-65 parts; and an ethylene tar distillate, 35-70 parts.The molecular structural formula of the Schiff base-nickel complex is as follows: the ethylene tar distillate refers to a distillate product of ethylene tar at a distillation temperature of 130-320 DEG C.The heavy oil catalytic viscosity reducer composition provided by the application can reduce the content of gum and asphaltene in heavy oil, crack macromolecules into small molecules, make heavy oil lighter, and realize irreversible viscosity reduction of heavy oil.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of tertiary oil recovery, and relates to a chemical viscosity reducer, in particular to a heavy oil catalytic viscosity reducer composition and a preparation method and application thereof. BACKGROUND

[0002] With the rapid growth of global oil consumption and the decreasing of conventional oil resources, heavy oil has gradually become the main object of oilfield mid-late stage production. The heavy oil reserves of Sinopec are 2.69x10 9 t, accounting for 30.7%, and mainly distributed in Shengli, Northwest and Henan oilfields. The heavy oil has high viscosity, large density and large flow resistance. The biggest difficulty in realizing heavy oil production is how to reduce the viscosity of heavy oil. At present, the methods for reducing the viscosity of heavy oil at home and abroad mainly include physical viscosity reduction, chemical viscosity reduction and microbial viscosity reduction. Among them, steam huff and puff and steam flooding have become the main production methods for heavy oil reservoirs, which have good effects on the production of ordinary heavy oil, but limited effects on the production of extra-heavy oil.

[0003] The heavy oil catalytic viscosity reduction technology is a kind of chemical viscosity reduction, and its biggest advantage is that it can realize irreversible viscosity reduction of heavy oil, ensure heavy oil production, improve oil quality, realize "underground oil refining", and has important significance for the production of heavy oil, especially extra-heavy oil. However, this technology still has some defects, such as lack of economic and effective heavy oil catalytic viscosity reducer, high temperature required for catalyst reaction, poor miscibility with heavy oil, and difficult operation, etc., which leads to difficult large-scale industrial application, and brings certain difficulties to the development and utilization of heavy oil resources.

[0004] Schiff base is a kind of compound with R1(R2)-C=N-R3 structure, which is formed by condensation of substances containing amine groups and substances containing active carbonyl groups. The core of Schiff base is the -C=N- group, and the N atom has a lone pair of electrons, which is easy to form a stable complex with metal ions, so as to cause the rupture of C-S bond, C-N bond, C-O bond and C-C bond in heavy oil heavy components, reduce the content of resin and asphaltene, and also cause the depolymerization of asphaltene aggregate. Therefore, Schiff base can be used as a main raw material for preparing heavy oil catalytic viscosity reducer.

[0005] Ethylene tar is the product of high-temperature condensation of raw materials and products in the steam cracking process of ethylene cracking raw materials. Ethylene tar is extremely complex in composition, and contains a large amount of indene, indene and its homologues, naphthalene, methyl naphthalene, ethyl naphthalene, dimethyl naphthalene, and anthracene, etc. The annual output of ethylene tar in China is very large, and most of it is burned as fuel. However, there are a large amount of naphthalene and its homologues in the light fraction of ethylene tar, and important chemical products such as pure naphthalene, α-methyl naphthalene and β-methyl naphthalene can be obtained from the tar by using the combined process of rectification, crystallization and recrystallization.

[0006] The application relates to a low-cost and high-performance catalytic viscosity reducer for thick oil, which is prepared by compounding a Schiff base metal complex and an ethylene tar fraction.

[0007] CN103525389B discloses a kind of nano nickel catalyst for oil displacement and a preparation method thereof, a kind of nano nickel catalyst for oil displacement and a preparation method thereof, the nano catalyst is mixed solution mixed by solute of nano nickel sulfate and nano tetradecyl benzene sulfonic acid, water and 120 number aromatic solvent oil and isopentyl alcohol.

[0008] CN101108334 discloses a solid strong acid catalyst for catalytic upgrading of thick oil.

[0009] CN1915488 discloses a catalyst for catalytic viscosity reduction of thick oil by hydrothermal cracking in well.

[0010] CN101570684B discloses a preparation method of a catalytic viscosity reducer for hydrothermal cracking of thick oil, a catalytic viscosity reducer for hydrothermal cracking of thick oil made of molybdenum salt, distilled water, alkali solution and aromatic acid, and reaction conditions include temperature of 180-280 DEG C, time of 24-48 h and high pressure, and the viscosity reduction rate for general thick oil and super thick oil is about 90%.

[0011] CN101440275B discloses an oxidative viscosity reducer for steam injection development of thick oil and a preparation method thereof, and the oxidative viscosity reducer takes peroxide, transition metal salt of organic acid, phosphate and alkaline substance as viscosity reducer components.

[0012] The above patents are different in the preparation of catalysts, and the prepared products are also different. The above patents have the following shortcomings or deficiencies: the raw material cost of the catalyst preparation is high, the preparation method is relatively complex and harsh, the intermediate in the preparation has a great influence on the environment, is not conducive to large-scale industrial production, the water-solubility of the prepared catalyst is poor, the on-site injection is difficult, and the on-site application is not conducive to popularization and application. SUMMARY

[0013] The present application aims at the deficiencies of the prior art and provides a thick oil catalytic viscosity reducer composition, a preparation method and application thereof.

[0014] Therefore, in order to achieve the above-mentioned purpose, in one aspect, the present application provides a thick oil catalytic viscosity reducer composition, the composition and mass components of which are as follows:

[0015] Schiff base-nickel complex 30-65 parts;

[0016] Ethylene tar fraction 35-70 parts;

[0017] The molecular structure of the Schiff base-nickel complex is as follows:

[0018]

[0019] The ethylene tar fraction refers to a fraction product of ethylene tar at a fraction temperature of 130-320℃.

[0020] In another aspect, the present application provides a preparation method of the above-mentioned thick oil catalytic viscosity reducer composition, and the preparation method is as follows:

[0021] (1) A salicylaldehyde is weighed and dissolved in a solvent, and placed in a three-necked flask equipped with a constant pressure dropping funnel, a heating reflux and stirring; ethylenediamine is weighed and dissolved in toluene, and added dropwise to the salicylaldehyde solution under stirring, and heated for reaction. After the reaction is completed, cooling, filtration and drying are performed to obtain a Schiff base ligand;

[0022] (2) The above-mentioned Schiff base ligand is dissolved in a solvent and placed in a three-necked flask equipped with a constant pressure dropping funnel and a reflux condenser; a transition metal nickel salt is weighed and dissolved in methanol, and added dropwise to the Schiff base ligand solution and stirred rapidly; heating is performed to obtain a reaction product;

[0023] (3) The above-mentioned reaction product is cooled, filtered and dried to obtain a Schiff base-nickel complex;

[0024] (4) The Schiff base-nickel complex is added to a reaction kettle, followed by adding an ethylene tar fraction, heating, stirring uniformly, and naturally cooling to obtain a catalytic viscosity reducer composition.

[0025] In a third aspect, the present application provides an application of the above-mentioned thick oil catalytic viscosity reducer composition in thick oil exploitation.

[0026] The application steps are as follows:

[0027] (1) First, the thick oil catalytic viscosity reducer composition is injected into a thick oil formation;

[0028] (2)Secondly, steam is injected to replace the heavy oil catalytic viscosity reducer composition, to improve the formation temperature, to establish the temperature field, and to disperse the heavy oil catalytic viscosity reducer composition better in the deep formation; the injection pressure and speed are limited to not exceed the upper limit of the oil reservoir fracture pressure;

[0029] (3) The well is closed for reaction, and then the well is opened for production.

[0030] The present application synthesizes a Schiff base complex with salicylaldehyde and ethylenediamine as raw materials, and then synthesizes a Schiff base metal complex by reacting the Schiff base complex with a transition metal nickel salt, and then compounds the ethylene tar fraction to prepare a low-cost and excellent-performance heavy oil catalytic viscosity reducer. The Schiff base-nickel complex and the ethylene tar fraction are compounded to cause the rupture of C-S bonds, C-N bonds, C-O bonds and C-C bonds in heavy oil heavy components, which can significantly reduce the viscosity of heavy oil, and the higher the temperature, the higher the viscosity reduction rate. The viscosity reduction rate at 200 DEG C is greater than or equal to 75%, and the viscosity reduction rate at 250 DEG C is greater than or equal to 85%. The content of gum and asphaltene is sufficiently reduced, the heavy oil is lightened, and irreversible viscosity reduction of heavy oil is realized.

[0031] Compared with the prior art, the present application has the following advantages and beneficial effects:

[0032] (1) The present application has the advantages of simple preparation process, mild reaction conditions, green environmental protection, and suitability for industrial production;

[0033] (2) The catalytic viscosity reducer provided by the present application has good solubility in heavy oil, which helps the catalytic viscosity reducer to play a role in the deep formation, and has a wide application prospect in the field of heavy oil exploitation;

[0034] (3) The present application is expected to realize high-value comprehensive utilization of ethylene tar, and at the same time provides a new opportunity for cost reduction and efficiency increase of heavy oil exploitation. DETAILED DESCRIPTION

[0035] The endpoints of the ranges and any values disclosed herein are not limited to the precise values stated. The endpoints of the ranges and the values are approximate values and should be understood to include values approximately near these ranges and values within these ranges. For ranges with endpoints, the endpoints are included in the ranges. For ranges with endpoints, the endpoints are included in the ranges. The ranges include the endpoints.

[0036] According to the first aspect of the present application, the present application provides a heavy oil catalytic viscosity reducer composition, and the composition and mass components of the catalytic viscosity reducer composition are as follows:

[0037] The Schiff base-nickel complex is 30-65 parts, more preferably 40-50 parts;

[0038] ethylene tar fraction 35-70 parts, more preferably 50-60 parts;

[0039] The molecular structure of the Schiff base-nickel complex is as follows:

[0040]

[0041] Preferably, the ethylene tar fraction refers to the fraction product of ethylene tar at a fraction temperature of 130-320℃, more preferably, the fraction temperature is 170-270℃.

[0042] In a second aspect, the present application provides a preparation method of the above-mentioned catalytic viscosity reducer composition, and the preparation method is as follows:

[0043] (1) weigh salicylaldehyde, dissolve it in a solvent, and place it in a three-necked flask equipped with a constant pressure dropping funnel, a heating reflux and stirring; weigh ethylenediamine, dissolve it in toluene, and drop it into the salicylaldehyde solution under stirring, heat and react, cool after reaction, filter and dry to obtain a Schiff base ligand;

[0044] (2) dissolve the above-mentioned Schiff base ligand in a solvent, and place it in a three-necked flask equipped with a constant pressure dropping funnel and a reflux condenser; weigh a transition metal nickel salt, dissolve it in methanol, drop it into the Schiff base ligand solution and stir quickly; heat and react to obtain a reaction product;

[0045] (3) cool, filter and dry the above-mentioned reaction product to obtain a Schiff base-nickel complex;

[0046] (4) add the above-mentioned Schiff base-nickel complex into a reaction kettle, then add ethylene tar fraction, heat and stir uniformly, and naturally cool to obtain a catalytic viscosity reducer composition.

[0047] In the present application, preferably, the molar ratio of salicylaldehyde, ethylenediamine and transition metal nickel salt is 1:2-3:1-2; more preferably, the molar ratio of salicylaldehyde, ethylenediamine and transition metal nickel salt is 1:2.2-2.4:1.1-1.3.

[0048] Preferably, the transition metal nickel salt in step (1) is one of nickel chloride, nickel chloride hexahydrate and nickel sulfate, more preferably, it is nickel chloride or nickel sulfate.

[0049] In the present application, preferably, the solvent in step (1) is one or a mixture of two of toluene and xylene, more preferably, it is toluene or xylene; the amount of the solvent is 8-12 times of the mass of salicylaldehyde.

[0050] Preferably, the amount of toluene in step (1) is 5-10 times of the mass of salicylaldehyde.

[0051] Preferably, the heating reaction in step (1) is carried out at a temperature of 90-130°C, more preferably 105-115°C, for 1-8h, more preferably 3-4h.

[0052] In the present application, preferably, the solvent in step (2) is methanol or ethanol, more preferably methanol; the solvent is used in an amount of 20-30 times the mass of salicylaldehyde.

[0053] Preferably, the amount of methanol used in step (2) is 5-10 times the mass of salicylaldehyde.

[0054] Preferably, the heating reaction in step (2) is carried out at a temperature of 50-78°C, more preferably 60-65°C, for 1-8h, more preferably 3-4h.

[0055] In the present application, preferably, the heating temperature in step (4) is 40-45°C; the stirring speed is 300-500rpm; and the stirring time is 30-60min.

[0056] The synthesis route of the Schiff base-nickel complex is as follows.

[0057]

[0058] In a third aspect, the present application provides the use of the above-mentioned catalytic viscosity reducer composition in the exploitation of heavy oil.

[0059] The steps of the use are as follows:

[0060] (1) First, the catalytic viscosity reducer composition for heavy oil is injected into the heavy oil formation;

[0061] (2) Then, steam is injected to replace the catalytic viscosity reducer composition for heavy oil, to increase the formation temperature, to establish a temperature field, and to better disperse the catalytic viscosity reducer composition for heavy oil in the deep formation; the injection pressure and speed of the steam are not more than the upper limit of the fracture pressure of the oil layer;

[0062] (3) The well is closed for reaction, and then opened for production.

[0063] The amount of the catalytic viscosity reducer composition and the steam used in the field application is not particularly required, and can be adjusted by those skilled in the art according to the need.

[0064] In the present application, preferably, the formation temperature is increased by 200°C or more, more preferably 250-320°C.

[0065] Preferably, the well closure time is 1-5d, more preferably 1-3d.

[0066] To make the above and other objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described in detail below.

[0067] In the following examples, the ethylene tar used was an ethylene tar sample provided by a chemical plant in Shandong Province.

[0068] This invention does not impose any particular requirements on the dosage of the heavy oil catalytic viscosity reducer composition in heavy oil viscosity reduction extraction applications; those skilled in the art can adjust it as needed. The following description of this invention exemplifies one application concentration, which should not be construed as a limitation of the invention.

[0069] In the following examples, unless otherwise specified, all reagents used are commercially available chemical reagents, and there are no particular restrictions on their use.

[0070] Example 1:

[0071] (1) Weigh 1 mol (122 g) of salicylaldehyde, dissolve it in 976 g of toluene, and place it in a three-necked flask equipped with a constant pressure dropping funnel, reflux heating and stirring; weigh 2 mol of ethylenediamine, dissolve it in 610 g of toluene, and add it dropwise to the salicylaldehyde solution under stirring. Heat the reaction for 1 h at 90 °C. After the reaction is complete, cool, filter, and dry to obtain Schiff base ligands.

[0072] (2) Dissolve the above Schiff base ligand in 2440g of methanol and place it in a three-necked flask equipped with a constant pressure dropping funnel and a reflux condenser; weigh 1mol of nickel chloride, dissolve it in 610g of methanol, add it dropwise to the Schiff base ligand solution and stir rapidly; heat the reaction at 50℃ for 1h to obtain the reactants;

[0073] (3) Cool, filter and dry the above reactants to obtain Schiff base-nickel complex;

[0074] (4) Add 30 parts of the above Schiff base-nickel complex to the reactor, and then add 35 parts of ethylene tar fraction with a distillation temperature of 130-170℃. Heat the mixture, stir until uniform, and heat at 40℃. Stir at 300 rpm for 30 min. Allow the mixture to cool naturally to obtain the catalytic viscosity reducer composition A1.

[0075] Example 2:

[0076] (1) Weigh 1 mol (122 g) of salicylaldehyde, dissolve it in 1025 g of xylene, and place it in a three-necked flask equipped with a constant pressure dropping funnel, reflux heating and stirring; weigh 2.2 mol of ethylenediamine, dissolve it in 780 g of toluene, and add it dropwise to the salicylaldehyde solution under stirring. Heat the reaction for 2 h at 105 °C. After the reaction is complete, cool, filter, and dry to obtain Schiff base ligands.

[0077] (2) The Schiff base ligand is dissolved in 2760 g of solvent methanol, and placed in a three-necked flask equipped with a constant pressure dropping funnel, a reflux condenser; 1.1 mol of nickel chloride hexahydrate is dissolved in 780 g of methanol, and added dropwise to the Schiff base ligand solution and stirred rapidly; the reaction is heated, the heating temperature is 56°C, and the reaction time is 2 h, to obtain a reaction product;

[0078] (3) The reaction product is cooled, filtered, and dried, to obtain a Schiff base-nickel complex;

[0079] (4) The Schiff base-nickel complex is added to the reaction kettle, 35 parts, and then ethylene tar fraction material with a distillation temperature of 150-210°C is added, 45 parts, heated, stirred uniformly, the heating temperature is 42°C, the stirring speed is 350 rpm, the stirring time is 35 min, and the temperature is naturally lowered, to obtain a catalytic viscosity reducer composition A2.

[0080] Example 3:

[0081] (1) 1 mol (122 g) of salicylaldehyde is dissolved in 1198 g of solvent toluene, and placed in a three-necked flask equipped with a constant pressure dropping funnel, a heating reflux, and stirring; 2.4 mol of ethylenediamine is dissolved in 910 g of toluene, and added dropwise to the salicylaldehyde solution under stirring, and heated for 3 h, the heating temperature is 115°C, after the reaction is completed, the temperature is cooled, filtered, and dried, to obtain a Schiff base ligand;

[0082] (2) The Schiff base ligand is dissolved in 2950 g of solvent methanol, and placed in a three-necked flask equipped with a constant pressure dropping funnel, a reflux condenser; 1.3 mol of nickel chloride is dissolved in 850 g of methanol, and added dropwise to the Schiff base ligand solution and stirred rapidly; the reaction is heated, the heating temperature is 65°C, and the reaction time is 3 h, to obtain a reaction product;

[0083] (3) The reaction product is cooled, filtered, and dried, to obtain a Schiff base-nickel complex;

[0084] (4) The Schiff base-nickel complex is added to the reaction kettle, 40 parts, and then ethylene tar fraction material with a distillation temperature of 180-250°C is added, 50 parts, heated, stirred uniformly, the heating temperature is 44°C, the stirring speed is 400 rpm, the stirring time is 50 min, and the temperature is naturally lowered, to obtain a catalytic viscosity reducer composition A3.

[0085] Example 4:

[0086] (1) 1 mol (122 g) of salicylaldehyde was weighed and dissolved in 1276 g of solvent dimethylbenzene, and placed in a three-necked flask equipped with a constant pressure dropping funnel, a heating reflux condenser and a stirrer; 2.6 mol of ethylenediamine was weighed and dissolved in 1050 g of toluene, and added dropwise to the salicylaldehyde solution under stirring, and heated to react for 4 h at 110°C; after the reaction was completed, the product was cooled, filtered and dried to obtain a Schiff base ligand;

[0087] (2) The Schiff base ligand was dissolved in 3120 g of solvent ethanol, and placed in a three-necked flask equipped with a constant pressure dropping funnel and a reflux condenser; 1.5 mol of nickel chloride hexahydrate was weighed and dissolved in 980 g of methanol, and added dropwise to the Schiff base ligand solution and stirred rapidly; the reaction was heated to 70°C for 5 h to obtain a reaction product;

[0088] (3) The reaction product was cooled, filtered and dried to obtain a Schiff base-nickel complex;

[0089] (4) The Schiff base-nickel complex was added to a reaction kettle, followed by adding 55 parts of ethylene tar fraction with a distillation temperature of 200-290°C, and heated to stir uniformly at a temperature of 43°C and a stirring speed of 450 rpm for 40 min, and then naturally cooled to obtain a catalytic viscosity reducer composition A4.

[0090] Example 5:

[0091] (1) 1 mol (122 g) of salicylaldehyde was weighed and dissolved in 1276 g of solvent dimethylbenzene, and placed in a three-necked flask equipped with a constant pressure dropping funnel, a heating reflux condenser and a stirrer; 2.6 mol of ethylenediamine was weighed and dissolved in 1050 g of toluene, and added dropwise to the salicylaldehyde solution under stirring, and heated to react for 4 h at 110°C; after the reaction was completed, the product was cooled, filtered and dried to obtain a Schiff base ligand;

[0092] (2) The Schiff base ligand was dissolved in 3120 g of solvent ethanol, and placed in a three-necked flask equipped with a constant pressure dropping funnel and a reflux condenser; 1.5 mol of nickel chloride hexahydrate was weighed and dissolved in 980 g of methanol, and added dropwise to the Schiff base ligand solution and stirred rapidly; the reaction was heated to 70°C for 5 h to obtain a reaction product;

[0093] (3) The reaction product was cooled, filtered and dried to obtain a Schiff base-nickel complex;

[0094] (4) The Schiff base-nickel complex was added to a reaction kettle, followed by adding 55 parts of ethylene tar fraction with a distillation temperature of 200-290°C, and heated to stir uniformly at a temperature of 43°C and a stirring speed of 450 rpm for 40 min, and then naturally cooled to obtain a catalytic viscosity reducer composition A4.

[0095] Example 6

[0096] (1) Take 1 mol (122 g) of salicylaldehyde, dissolve it in 1464 g of dimethylbenzene, and place it in a three-necked flask equipped with a constant pressure dropping funnel, a heating reflux, and stirring; take 3 mol of ethylenediamine, dissolve it in 1220 g of toluene, and drop it into the salicylaldehyde solution under stirring; heat the reaction for 8 h at a temperature of 130°C; after the reaction is completed, cool it, filter it, and dry it to obtain a Schiff base ligand;

[0097] (2) Dissolve the above-mentioned Schiff base ligand in 3660 g of solvent ethanol, and place it in a three-necked flask equipped with a constant pressure dropping funnel and a reflux condenser; take 2 mol of nickel sulfate, dissolve it in 1220 g of methanol, and drop it into the Schiff base ligand solution and stir it quickly; heat the reaction at a temperature of 78°C for 8 h to obtain a reaction product;

[0098] (3) Cool the above-mentioned reaction product, filter it, and dry it to obtain a Schiff base-nickel complex;

[0099] (4) Add 65 parts of the above-mentioned Schiff base-nickel complex to the reaction kettle, and then add 70 parts of ethylene tar fraction with a distillation temperature of 250-320°C; heat it at a temperature of 45°C, stir it uniformly at a stirring speed of 500 rpm for 60 min, and naturally cool it to obtain a catalytic viscosity reducer composition A6.

[0100] Comparative Example 1

[0101] Schiff base-nickel complex, numbered CJN-1.

[0102] Comparative Example 2

[0103] Ethylene tar fraction in a temperature range of 170-270°C, numbered CJN-2.

[0104] Test Example 1

[0105] The thick oil used in the experiment has a viscosity of 89522 mPa·s at 50°C; the formation water used in the experiment has a salinity of 20520 mg / L.

[0106] The experimental steps are as follows:

[0107] (1) Kettle loading: take 200 g of thick oil, take 4 g of thick oil catalytic viscosity reducer composition A1-A6, CJN-1, CJN-2, and 20 g of formation water, slowly pour them into a high-pressure reaction kettle, seal the reaction kettle, and open the stirrer to stir it to make the catalyst fully dispersed in the oil sample, and the stirring speed is 100 r / min, about 2 min.

[0108] (2) Ventilation: open the nitrogen cylinder, and open the gas exhaust valve to slowly release the gas, keeping the pressure in the reactor at 1 MPa, 2 min after closing the inlet valve, and closing the exhaust valve after the pressure in the reactor is zero, keeping the initial pressure at zero.

[0109] (3) Reaction: set the temperature value, open the heating power and motor cooling system, start the stirrer, and the stirring rate is 100 r / min, when the temperature rises to 50℃, adjust the stirring rate to 500 r / min. When the temperature rises to the set temperature, start timing, keep this state for 10 hours, stop heating, and cool the reaction system to room temperature. Open the reactor, draw out the bottom sediment water, take out the oil sample after reaction, and measure the viscosity of the oil sample after electric field dehydration at the set temperature. The viscosity reduction rate of thick oil is calculated according to the following formula:

[0110] K = (μ0-μ) / μ0x100%

[0111] In the formula, K is the viscosity reduction rate of thick oil;

[0112] μ0 is the viscosity of thick oil before reaction, mPa·s;

[0113] μ is the viscosity of thick oil after reaction, mPa·s.

[0114] In addition, the four-component content of thick oil before and after reaction is tested respectively, and the influence of the catalyst on the components of thick oil is analyzed.

[0115] The viscosity reduction rate test results are shown in Table 1.

[0116] Table 1 Viscosity reduction rate of thick oil before and after treatment under different conditions

[0117] No. Catalytic viscosity reducer Temperature / °C Viscosity reduction rate / % Temperature / °C Viscosity reduction rate / % 1 [A1] 200 77.5 250 87.5 2 [A2] 200 76.6 250 86.6 3 [A3] 200 77.2 250 87.2 4 [A4] 200 76.1 250 86.1 5 [A5] 200 75.4 250 85.4 6 [A6] 200 71.4 250 81.4 7 CJN-1 200 48.2 250 57.1 8 CJN-2 200 39.6 250 44.7

[0118] As can be seen from Table 1, compared with CJN-1 and CJN-2, the thick oil catalytic viscosity reducer composition provided by the application can more obviously reduce the viscosity of thick oil, and the higher the temperature, the higher the viscosity reduction rate.

[0119] Under different treatment conditions, the comparison of group composition of thick oil before and after catalytic viscosity reduction is shown in Table 2 and Table 3.

[0120] Table 2 Comparison of group composition of thick oil before and after 200℃ treatment under different conditions

[0121]

[0122]

[0123] Table 3 Comparison of group composition of thick oil before and after 250℃ treatment under different conditions

[0124]

[0125] As can be seen from Table 2 and Table 3, the heavy oil catalytic viscosity reducer composition provided by the application more obviously reduces the content of heavy components compared with CJN-1 and CJN-2, and the higher the temperature is, the greater the reduction range of heavy components is, and the irreversible viscosity reduction of heavy oil can be achieved.

[0126] Application Example 1 A4 Field Application

[0127] The test is aimed at heavy oil M in a block of Shengli Oilfield, the reservoir temperature is 65℃, the crude oil viscosity is 27826 mPa·s, which belongs to super heavy oil, the emulsified water content is 23.8%, the injected water salinity is 24150 mg / L, the calcium and magnesium ion concentration is 421 mg / L, and the original formation pressure is 13.6 MPa. Since the crude oil viscosity of the well is large, the effects of steam stimulation and steam flooding for developing the block are poor, and in 2022, a heavy oil catalytic viscosity reducer flooding development test of one well group (one injection and four production) is carried out.

[0128] 80 m3 of the heavy oil catalytic viscosity reducer composition A4 solution with a concentration of 50% is injected into the heavy oil formation, and then steam is injected to replace the catalytic viscosity reducer composition, the formation temperature is increased, the temperature field is established, and the catalytic viscosity reducer composition is better dispersed in the deep formation; the injection pressure and speed are limited to not more than the upper limit of the oil reservoir fracture pressure; the well is closed for reaction, and then the well is opened for production. The amount of the catalytic viscosity reducer composition and the steam in the field application is not particularly required, and the person skilled in the art adjusts it according to the need. The formation temperature increase value is 200℃ or more, the well is closed for 3 days, and then the well is opened for production.

[0129] The initial daily liquid of the well group is 19.0 t / d, the daily oil is 7.2 t / d, and the water content is 62.1%, and the peak daily oil is 29.4 t / d. At present, the daily liquid of the well group is 52.8 t / d, the daily oil is 18.1 t / d, the water content is 65.7%, the cumulative incremental oil is 8451.2 t, and it continues to be effective, indicating that the heavy oil catalytic viscosity reducer of the application obviously improves the recovery rate.

[0130] Application Example 2 A5 Field Application

[0131] The test is aimed at heavy oil X in a block of Shengli Oilfield, the reservoir temperature is 50℃, the crude oil viscosity is 25006 mPa·s, which belongs to super heavy oil, the emulsified water content is 13.8%, the injected water salinity is 8320 mg / L, the calcium and magnesium ion concentration is 336 mg / L, and the original formation pressure is 18.2 MPa. Since the crude oil viscosity of the well is large, the effects of steam stimulation and steam flooding for developing the block are poor, and in 2022, a heavy oil catalytic viscosity reducer flooding development test of one well group (one injection and six production) is carried out.

[0132] A5 solution of 90 m3 of 50% concentration is injected into the heavy oil formation, followed by injecting steam to replace the catalytic viscosity reducer composition, to increase the formation temperature, establish a temperature field, and better disperse the catalytic viscosity reducer composition in the deep formation; the injection pressure and speed of the steam are limited to not exceed the upper limit of the reservoir fracture pressure; the well is closed for reaction, and then opened for production. Among them, the amount of catalytic viscosity reducer composition and steam used in the field application is not particularly required, and the person skilled in the art adjusts according to the needs. The formation temperature increase value is 250℃ or more, the well is closed for 4d, and then opened for production.

[0133] The initial daily liquid of the well group is 21.0t / d, the daily oil is 9.1t / d, the water content is 62.1%, and the peak daily oil is 15.4t / d. At present, the daily liquid of the well group is 82.8t / d, the daily oil is 38.1t / d, the water content is 54.0%, the cumulative oil increment is 10226.2t, and it continues to be effective, indicating that the heavy oil catalytic viscosity reducer of the present application has obviously improved the recovery rate.

[0134] Application example 3 A6 field application

[0135] The test is aimed at a block of Shengli Oilfield heavy oil P, the reservoir temperature is 80℃, the crude oil viscosity is 34996mPa·s, which belongs to super heavy oil, the emulsified water content is 22.2%, the injected water salinity is 17720mg / L, the calcium and magnesium ion concentration is 544mg / L, and the original formation pressure is 15.7MPa. Due to the high viscosity of the crude oil in the well, the effects of steam stimulation and steam flooding for developing the block are poor, and in 2022, a heavy oil catalytic viscosity reducer flooding development test was carried out in a well group (one injection and eight production).

[0136] A6 solution of 120 m3 of 50% concentration is injected into the heavy oil formation, followed by injecting steam to replace the catalytic viscosity reducer composition, to increase the formation temperature, establish a temperature field, and better disperse the catalytic viscosity reducer composition in the deep formation; the injection pressure and speed of the steam are limited to not exceed the upper limit of the reservoir fracture pressure; the well is closed for reaction, and then opened for production. Among them, the amount of catalytic viscosity reducer composition and steam used in the field application is not particularly required, and the person skilled in the art adjusts according to the needs. The formation temperature increase value is 300℃ or more, the well is closed for 5d, and then opened for production.

[0137] The initial daily liquid of the well group is 40.0t / d, the daily oil is 17.5t / d, the water content is 56.3%, and the peak daily oil is 27.1t / d. At present, the daily liquid of the well group is 120.8t / d, the daily oil is 48.1t / d, the water content is 60.2%, the cumulative oil increment is 19804.2t, and it continues to be effective, indicating that the heavy oil catalytic viscosity reducer of the present application has obviously improved the recovery rate.

[0138] The preferred embodiments of the present application are described in detail above, but the present application is not limited to the specific details described in the above embodiments, and various simple modifications can be made to the technical solutions of the present application within the technical concept of the present application, and these simple modifications all belong to the protection scope of the present application.

[0139] In addition, it should be noted that each specific technical feature described in the above specific embodiments can be combined in any appropriate manner without contradiction, and in order to avoid unnecessary repetition, the present application will not further describe various possible combinations.

[0140] In addition, various different embodiments of the present application can also be combined in any manner, as long as it does not violate the present application.

Claims

1. A heavy oil catalytic viscosity reducer composition characterized by, The composition and quality components are as follows: Schiff base-nickel complex 30-65 parts; Ethylene tar fraction 35-70 parts; The molecular structure of the Schiff base-nickel complex is as follows: The ethylene tar fraction refers to the fraction product of ethylene tar at a fraction temperature of 130-320℃.

2. The heavy oil catalytic viscosity reducer composition according to claim 1, wherein The fraction temperature is 170-270℃.

3. The method of claim 1 or 2, wherein the preparation of the heavy oil catalytic viscosity reducer composition is characterized by, The preparation method is as follows: (1) Salicylaldehyde is weighed and dissolved in a solvent, and placed in a three-necked flask equipped with a constant pressure dropping funnel, a heating reflux and stirring; ethylenediamine is weighed and dissolved in toluene, and added dropwise to the salicylaldehyde solution under stirring, heated and reacted, cooled after reaction, filtered and dried to obtain a Schiff base ligand; (2) The Schiff base ligand is dissolved in a solvent, and placed in a three-necked flask equipped with a constant pressure dropping funnel and a reflux condenser; a transition metal nickel salt is weighed and dissolved in methanol, and added dropwise to the Schiff base ligand solution and stirred rapidly; heated and reacted to obtain a reaction product; (3) The reaction product is cooled, filtered and dried to obtain a Schiff base-nickel complex; (4) The Schiff base-nickel complex is added to a reaction kettle, followed by the addition of ethylene tar fraction, heated and stirred uniformly, and naturally cooled to obtain a catalytic viscosity reducer composition.

4. The process for preparing the heavy oil catalytic viscosity reducer composition according to claim 3, characterized by, The molar ratio of salicylaldehyde, ethylenediamine and transition metal nickel salt is 1:2-3:1-2.

5. The process for preparing the heavy oil catalytic viscosity reducer composition according to claim 4, characterized by, The molar ratio of salicylaldehyde, ethylenediamine and transition metal nickel salt is 1:2.2-2.4:1.1-1.

3.

6. The process for preparing the heavy oil catalytic viscosity reducer composition according to claim 3, wherein the process is characterized by, The transition metal nickel salt in step (1) is one of nickel chloride, nickel chloride hexahydrate and nickel sulfate.

7. The process for preparing the heavy oil catalytic viscosity reducer composition according to claim 3, wherein the process is characterized by, The solvent in step (1) is one or a mixture of two of toluene and xylene.

8. The process for preparing the heavy oil catalytic viscosity reducer composition according to claim 3, wherein the process is characterized by, The heating reaction temperature in step (1) is 90-130℃, and the heating reaction time is 1-8h.

9. The process for preparing the heavy oil catalytic viscosity reducer composition according to claim 8, characterized by, The heating reaction temperature in step (1) is 105-115℃, and the heating reaction time is 3-4h.

10. The process for preparing the heavy oil catalytic viscosity reducer composition according to claim 3, wherein the process is characterized by, The solvent in step (2) is one or a mixture of two of methanol and ethanol.

11. The process for preparing the heavy oil catalytic viscosity reducer composition according to claim 3, wherein the process is characterized by, The heating reaction temperature in step (2) is 50-78℃, and the heating reaction time is 1-8h.

12. The process for preparing the heavy oil catalytic viscosity reducer composition according to claim 11, wherein the process is characterized by, The heating reaction temperature in step (2) is 60-65℃, and the heating reaction time is 3-4h.

13. The process for preparing the heavy oil catalytic viscosity reducer composition according to claim 3, wherein the process is characterized by, The heating temperature in step (4) is 40-45℃, the stirring speed is 300-500rpm, and the stirring time is 30-60min.

14. The use of the thick oil catalytic viscosity reducer composition of claim 1 or 2 in thick oil exploitation.

15. The use according to claim 14, wherein the compound is ###00010### or a pharmaceutically acceptable salt thereof. The steps of the use are as follows: (1) The thick oil catalytic viscosity reducer composition is first injected into a thick oil formation; (2) Steam is then injected to replace the thick oil catalytic viscosity reducer composition, to increase the formation temperature, establish a temperature field, and better disperse the thick oil catalytic viscosity reducer composition in the deep formation; the injection pressure and speed are limited to not exceeding the upper limit of the oil layer fracture pressure; (3) The well is closed for reaction, and then opened for production.

16. The use according to claim 15, wherein The formation temperature increase value in step (2) is 200℃ or more.

17. The use according to claim 15, wherein the compound is ###00009### 15 The well closure time in step (3) is 1-5d.

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