Inorganic gel coalescence inhibitor as well as preparation method and application thereof

Abstract

The invention provides an inorganic gel coalescence inhibitor as well as a preparation method and application thereof, the inorganic gel coalescence inhibitor is prepared from the following raw materials in specific parts: acrylamide, a temperature-resistant and salt-resistant monomer, a cationic monomer and an initiator, and the acrylamide, the temperature-resistant and salt-resistant monomer and the cationic monomer are matched to prepare the inorganic gel coalescence inhibitor. The inorganic gel coalescence inhibitor has high steric effect and cationic group shielding effect, can inhibit rapid coalescence of silicate and metal cations to form precipitates, can effectively delay gelation time of inorganic gel, is further applied to profile control, flooding and water control of a high-water-content oil field, and has a good application prospect. The expansion of the swept volume of injected water is facilitated, the water flooding swept effect is improved, and good application prospects are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of oil field development, and in particular relates to an inorganic gel polymerization inhibitor and a preparation method and application thereof. Background Art

[0002] With the continuous progress of oil field exploitation, the late stage of water injection development of old oil fields has caused the single-layer advance of injected water due to long-term water injection, and the interlayer contradiction and interference are very serious. Deep liquid flow diversion and drive adjustment technology is an important means to solve the inefficient and ineffective cycle of water injection in water-driven oil fields and improve the recovery rate of water-driven development.

[0003] The commonly used inorganic gel flooding systems include silicate systems such as water glass and sodium silicate. CN112625666A discloses an oilfield oily sludge plugging agent and a preparation method thereof, and the operation steps are as follows: fully dry the oily sludge sample to obtain dry sludge; then crush the dry sludge and sieve to obtain dry sludge powder; mix water with the dry sludge powder, add a rheology modifier under stirring, and then stir, then add a curing time controller and a gel strength regulator in sequence and stir, and finally add the dry sludge powder and continue stirring to obtain a suspension; put the obtained suspension into a sealed bag, put it in a constant temperature water bath at 50°C, and let it stand for 3 to 25 days to obtain the oilfield oily sludge plugging agent.

[0004] However, due to the interaction between silicate ions and divalent metal ions (Ca 2+ Mg 2+ ) will quickly generate precipitation after meeting, especially under high temperature conditions, the speed of gelation cannot be controlled, and it is very easy to form a blockage in the near-wellbore area, which brings great difficulties to the subsequent injection of plugging agents; at the same time, the double-liquid method is generally used for injection during on-site construction, and clean water is used as an isolation plug between the silicate plug and the calcium chloride plug. The injection is rotated and alternately rotated many times, which brings inconvenience to the on-site construction. At the same time, the clean water isolation plug added cannot completely isolate the silicate and calcium chloride effectively, resulting in gelation in the near-wellbore area, which seriously affects the efficiency of oilfield development.

[0005] Therefore, in order to solve the above technical problems, it is urgent to develop an inorganic gel polymerization inhibitor that can effectively inhibit the polymerization and precipitation of silicate and divalent metal ions. Summary of the invention

[0006] In view of the deficiencies in the prior art, the object of the present invention is to provide an inorganic gel polymerization inhibitor and a preparation method and application thereof. The inorganic gel polymerization inhibitor has a cationic shielding effect and a steric hindrance effect, which can inhibit the rapid polymerization of silicate and divalent metal ions to form precipitation, and can delay the gelation time of the inorganic gel, and has an obvious viscosity-increasing effect, thereby enabling the injection of water to expand the swept volume, effectively improving the water drive sweep effect.

[0007] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides an inorganic gel polymerization inhibitor, wherein the raw materials for preparing the inorganic gel polymerization inhibitor include the following components in parts by weight:

[0009]

[0010] Wherein, the acrylamide may be 15.5 parts by weight, 16 parts by weight, 16.5 parts by weight, 17 parts by weight, 17.5 parts by weight, 18 parts by weight, 18.5 parts by weight, 19 parts by weight or 19.5 parts by weight, etc.

[0011] The temperature-resistant and salt-resistant monomer can be 3.5 parts by weight, 4 parts by weight, 4.5 parts by weight, 5 parts by weight, 5.5 parts by weight, 6 parts by weight, 6.5 parts by weight, 7 parts by weight, 7.5 parts by weight, 8 parts by weight or 8.5 parts by weight, etc.

[0012] The cationic monomer may be 4.5 parts by weight, 5 parts by weight, 5.5 parts by weight, 6 parts by weight, 6.5 parts by weight, 7 parts by weight, 7.5 parts by weight, etc.

[0013] The initiator may be 0.25 parts by weight, 0.3 parts by weight, 0.35 parts by weight, 0.4 parts by weight, or 0.45 parts by weight.

[0014] The raw materials for preparing the inorganic gel polymerization inhibitor provided by the present invention include specific portions of acrylamide, a heat-resistant and salt-resistant monomer, a cationic monomer and an initiator. By selecting the above-mentioned acrylamide, the heat-resistant and salt-resistant monomer and the cationic monomer for matching, the obtained inorganic gel polymerization inhibitor has a higher steric hindrance effect and a cationic group shielding effect, can inhibit silicate radicals and metal cations from rapidly polymerizing to form precipitation, and can also delay the gelation time of the inorganic gel, and is further applied to water control in high-water-content oilfields, which helps to expand the swept volume of injected water and improve the water drive sweep effect.

[0015] Preferably, the temperature-resistant and salt-resistant monomer includes any one of N-vinyl pyrrolidone, 2-vinyl morpholine or sodium vinyl sulfonate, or a combination of at least two of them, and more preferably 2-vinyl morpholine and sodium vinyl sulfonate.

[0016] Preferably, the cationic monomer includes any one of dimethyldiallylammonium chloride, methacryloyloxyethyltrimethylammonium chloride, acryloyloxyethyltrimethylammonium chloride or allyltrimethylammonium chloride, or a combination of at least two thereof, and more preferably allyltrimethylammonium chloride.

[0017] Preferably, the initiator includes any one of ammonium persulfate, sodium persulfate, sodium pyrosulfite, sodium sulfite, tetramethylethylenediamine or triethylamine, or a combination of at least two thereof, and more preferably tetramethylethylenediamine, ammonium persulfate and sodium bisulfite.

[0018] Preferably, the raw materials for preparing the inorganic gel polymerization inhibitor also include water.

[0019] Preferably, the water content in the raw material for preparing the inorganic gel polymerization inhibitor is 62.5-77.8 parts by weight, for example, 64 parts by weight, 66 parts by weight, 68 parts by weight, 70 parts by weight, 72 parts by weight, 74 parts by weight or 76 parts by weight.

[0020] In a second aspect, the present invention provides a method for preparing the inorganic gel polymerization inhibitor as described in the first aspect, the preparation method comprising: mixing acrylamide, a temperature-resistant and salt-resistant monomer and a cationic monomer in water, adding an initiator to carry out a polymerization reaction, and obtaining the inorganic gel polymerization inhibitor.

[0021] Preferably, the polymerization reaction temperature is 12-16°C, for example, 12.5°C, 13°C, 13.5°C, 14°C, 14.5°C, 15°C or 15.5°C.

[0022] Preferably, the polymerization reaction time is 4 to 6 h, for example, 4.2 h, 4.4 h, 4.6 h, 4.8 h, 5 h, 5.2 h, 5.4 h, 5.6 h or 5.8 h.

[0023] Preferably, after the polymerization reaction is completed, the steps of granulation, drying and screening are further included.

[0024] In a third aspect, the present invention provides a use of the inorganic gel polymerization inhibitor as described in the first aspect in an oil field development process.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) The raw materials for preparing the inorganic gel polymerization inhibitor provided by the present invention include acrylamide, a temperature-resistant and salt-resistant monomer, a cationic monomer and an initiator in specific proportions. By selecting the above-mentioned acrylamide, the temperature-resistant and salt-resistant monomer and the cationic monomer for matching, the obtained inorganic gel polymerization inhibitor has a higher steric effect and a shielding effect of the cationic group, can inhibit the rapid polymerization of silicate and divalent metal ions to form precipitation, and can also delay the gelation time of the inorganic gel, and is further applied to the water control in the high-water-content oil field, which helps to expand the swept volume of the injected water and improve the water flooding sweep effect;

[0027] (2) The preparation process of the inorganic gel polymerization inhibitor provided by the present invention is simple, and acrylamide, a temperature-resistant and salt-resistant monomer, a cationic monomer and an initiator can be directly reacted, which is suitable for mass production;

[0028] (3) Specifically, the inorganic gel aggregation inhibitor provided by the present invention is in high mineralization salt water (10×10 4 mg / L simulated saline, Ca 2+ =4000mg / L), the apparent viscosity of the inorganic gel polymerization inhibitor with a mass percentage of 0.4% reaches more than 89.4mPa·s, which is twice that of the conventional HPAM polymer, and the viscosity-increasing effect is obvious; and the particle size of the inorganic gel particles formed after adding the inorganic gel polymerization inhibitor with a mass percentage of 0.4% provided by the present invention is 75-85nm, which is only about 1 / 3 of the particle size of the HPAM polymer, and the particle size of the polymerization particles is significantly reduced, which has a good application prospect. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only used to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0030] Example 1

[0031] An inorganic gel polymerization inhibitor, the preparation method of which comprises: adding the following deionized water (77.8 parts by weight), acrylamide (15 parts by weight), sodium vinyl sulfonate (2 parts by weight), 2-vinyl morpholine (1 part by weight), and allyl trimethyl ammonium chloride (4 parts by weight) in sequence into a wide-mouth bottle with a stopper, introducing nitrogen for 20 minutes, controlling the polymerization temperature to be 12°C, adding tetramethylethylenediamine (0.1 parts by weight), ammonium persulfate (0.075 parts by weight), and sodium bisulfite (0.025 parts by weight), continuing to introduce nitrogen for 10 minutes, performing polymerization reaction for 5 hours, granulating the obtained polymer colloid, drying at 60°C for 8 hours, and passing through a 50-mesh standard sieve to obtain the inorganic gel polymerization inhibitor.

[0032] Example 2

[0033] An inorganic gel polymerization inhibitor, the preparation method of which comprises: adding the following deionized water (71.7 parts by weight), acrylamide (18 parts by weight), sodium vinyl sulfonate (3 parts by weight), 2 parts by weight of 2-vinyl morpholine (2 parts by weight) and allyl trimethyl ammonium chloride (5 parts by weight) in a stoppered wide-mouth bottle in sequence, introducing nitrogen for 20 minutes, controlling the polymerization temperature to be 12°C, adding tetramethylethylenediamine (0.14 parts by weight), ammonium persulfate (0.12 parts by weight) and sodium bisulfite (0.04 parts by weight), continuing to introduce nitrogen for 10 minutes, carrying out polymerization reaction for 5 hours, granulating the obtained polymer colloid, drying at 60°C for 8 hours, and passing through a 50-mesh standard sieve to obtain the inorganic gel polymerization inhibitor.

[0034] Example 3

[0035] An inorganic gel polymerization inhibitor, the preparation method of which comprises: adding the following deionized water (66.6 parts by weight), acrylamide (20 parts by weight), sodium vinyl sulfonate (4 parts by weight), 2-vinyl morpholine (3 parts by weight) and allyl trimethyl ammonium chloride (6 parts by weight) in sequence into a stoppered wide-mouth bottle, introducing nitrogen for 20 minutes, controlling the polymerization temperature to be 12°C, adding tetramethylethylenediamine (0.2 parts by weight), ammonium persulfate (0.15 parts by weight) and sodium bisulfite (0.05 parts by weight), continuing to introduce nitrogen for 10 minutes, carrying out polymerization reaction for 5 hours, granulating the obtained polymer colloid, drying at 60°C for 8 hours, and passing through a 50-mesh standard sieve to obtain the inorganic gel polymerization inhibitor.

[0036] Example 4

[0037] An inorganic gel polymerization inhibitor, the preparation method of which comprises: adding the following deionized water (62.5 parts by weight), acrylamide (20 parts by weight), sodium vinyl sulfonate (5 parts by weight), 2-vinyl morpholine (4 parts by weight) and allyl trimethyl ammonium chloride (8 parts by weight) in sequence into a wide-mouth bottle with a stopper, introducing nitrogen for 20 minutes, controlling the polymerization temperature to be 12°C, adding tetramethylethylenediamine (0.26 parts by weight), ammonium persulfate (0.18 parts by weight) and sodium bisulfite (0.06 parts by weight), continuing to introduce nitrogen for 10 minutes, carrying out polymerization reaction for 5 hours, granulating the obtained polymer colloid, drying at 60°C for 8 hours, and passing through a 50-mesh standard sieve to obtain the inorganic gel polymerization inhibitor.

[0038] Comparative Example 1

[0039] An inorganic gel polymerization inhibitor, which differs from Example 1 only in that allyltrimethylammonium chloride is not added, and other substances, amounts and preparation methods are the same as those in Example 1.

[0040] Comparative Example 2

[0041] An inorganic gel polymerization inhibitor, which differs from Example 2 only in that allyltrimethylammonium chloride is not added, and other substances, amounts and preparation methods are the same as those in Example 2.

[0042] Comparative Example 3

[0043] An inorganic gel polymerization inhibitor, which differs from Example 3 only in that allyltrimethylammonium chloride is not added, and other substances, amounts and preparation methods are the same as those in Example 3.

[0044] Comparative Example 4

[0045] An inorganic gel polymerization inhibitor, which differs from Example 4 only in that allyltrimethylammonium chloride is not added, and other substances, amounts and preparation methods are the same as those of Example 4.

[0046] Comparative Example 5

[0047] An inorganic gel polymerization inhibitor is different from Example 1 in that 2-vinylmorpholine and sodium vinylsulfonate are not added, and other substances, amounts and preparation methods are the same as those in Example 1.

[0048] Comparative Example 6

[0049] A conventional polymer inhibitor, specifically HPAM.

[0050] Performance Test:

[0051] (1) Viscosity enhancement performance:

[0052] In a 250 mL beaker, add 99.5 parts by weight (10 × 10 4 mg / L, Ca 2+ =4000 mg / L) of simulated saline, start an electric stirrer, and then slowly add different weight portions of the inhibitors provided in the embodiments and comparative examples into the beaker (so that the mass percentage of the inhibitors is 0.2%, 0.3% and 0.4%, respectively), stir continuously for 60 minutes until it is completely dissolved, and test the apparent viscosity;

[0053] The inhibitors provided in Examples 1 to 4 and Comparative Examples 1 to 6 were tested according to the above test method. The test results are shown in Table 1:

[0054] Table 1

[0055]

[0056]

[0057] It can be seen from the data in Table 1 that as the concentration of the inorganic gel polymerization inhibitor increases, the apparent viscosity increases accordingly. At the same concentration, the inorganic gel polymerization inhibitor provided by Example 3 has the best viscosity-increasing effect, and the conventional HPAM polymer inhibitor provided by Comparative Example 6 has the worst viscosity-increasing effect.

[0058] (2) Delaying the aggregation effect:

[0059] Using 10×10 4 mg / L simulated saline (Ca 2+=4000mg / L) were used to prepare inhibitor solutions with mass percentages of 0.2%, 0.3% and 0.4%, respectively, and an electric stirrer was started to stir continuously at 400r / min for 60min; a 20% sodium silicate solution was prepared with deionized water, and the inhibitor solution and the sodium silicate solution were mixed at a weight ratio of 97.5:2.5 and 95:5, and then stirred evenly (the mass percentages of sodium silicate in the mixed solution were 0.5% and 1%, respectively), and then placed in a drying oven adjusted to 80°C for 8h, and the particle size of the polymerized particles was tested using a laser particle size analyzer to evaluate the effect of the polymer in retarding the aggregation of the inorganic gel particles.

[0060] The inhibitors provided in Examples 1 to 4 and Comparative Examples 1 to 6 were tested according to the above test method. The test results are shown in Table 2:

[0061] Table 2

[0062]

[0063]

[0064] According to the data in Table 2, it can be seen that as the concentration of the inhibitor increases, the particle size of the inorganic gel particles gradually decreases, and at the same concentration, the inorganic gel polymerization inhibitor provided in Example 3 has the best inhibitory effect on polymerization;

[0065] By comparing the data of Example 1 and Comparative Example 1, Example 2 and Comparative Example 2, Example 3 and Comparative Example 3, and Example 4 and Comparative Example 4, it can be seen that the particle size of the polymerized particles formed by the 0.4% inhibitor provided in Examples 1 to 4 and the 0.5% sodium silicate solution is only 75 to 85 nm, while the particle size of the polymerized particles formed by the 0.4% inhibitor provided in Comparative Examples 1 to 4 and the 0.5% sodium silicate solution is as high as 170 to 185 nm, and the particle size is significantly increased. This is because under the same conditions, the inhibitors provided in Comparative Examples 1 to 4 lack the shielding effect of the cationic groups due to the absence of allyltrimethylammonium chloride in the preparation raw materials, resulting in a reduced effect of delaying particle aggregation, and the particle size of the formed inorganic gel particles is significantly increased.

[0066] Further comparison of the data of Example 1 and Comparative Example 5 also shows that the inhibitor provided in Comparative Example 5 has poor salt resistance due to the absence of 2-vinylmorpholine and sodium vinylsulfonate in the preparation raw materials, and the particle size of the formed inorganic gel particles is also larger.

[0067] Finally, by comparing the data of Example 1 and Comparative Example 6, it can be seen that the HPAM polymer provided in Comparative Example 6 has a poor effect in delaying particle aggregation, and the particle size of the polymerized particles formed by 0.4% HPAM polymer and 0.5% sodium silicate solution is as high as 265 nm.

[0068] The applicant declares that the present invention illustrates an inorganic gel polymerization inhibitor and its preparation method and application through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned process steps, that is, it does not mean that the present invention must rely on the above-mentioned process steps to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the raw materials selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. An inorganic gel polymerization inhibitor, characterized in that: The raw materials for preparing the inorganic gel polymerization inhibitor include the following components in parts by weight: 15-20 parts by weight of acrylamide; 3 to 9 parts by weight of heat-resistant and salt-resistant monomer; 4 to 8 parts by weight of cationic monomer; Initiator 0.2-0.5 parts by weight.

2. The inorganic gel polymerization inhibitor according to claim 1, characterized in that: The temperature-resistant and salt-resistant monomer includes any one of N-vinyl pyrrolidone, 2-vinyl morpholine or sodium vinyl sulfonate or a combination of at least two thereof, preferably 2-vinyl morpholine and sodium vinyl sulfonate.

3. The inorganic gel polymerization inhibitor according to claim 1 or 2, characterized in that: The cationic monomer includes any one of dimethyldiallylammonium chloride, methacryloyloxyethyltrimethylammonium chloride, acryloyloxyethyltrimethylammonium chloride or allyltrimethylammonium chloride or a combination of at least two thereof, preferably allyltrimethylammonium chloride.

4. The inorganic gel polymerization inhibitor according to any one of claims 1 to 3, characterized in that: The initiator includes any one of ammonium persulfate, sodium persulfate, sodium pyrosulfite, sodium sulfite, tetramethylethylenediamine or triethylamine, or a combination of at least two thereof, preferably tetramethylethylenediamine, ammonium persulfate and sodium bisulfite.

5. The inorganic gel polymerization inhibitor according to any one of claims 1 to 4, characterized in that: The raw materials for preparing the inorganic gel polymerization inhibitor also include water.

6. The inorganic gel polymerization inhibitor according to claim 5, characterized in that: The water content in the raw material for preparing the inorganic gel polymerization inhibitor is 62.5 to 77.8 parts by weight.

7. A method for preparing the inorganic gel polymerization inhibitor according to any one of claims 1 to 6, characterized in that: The preparation method comprises: mixing acrylamide, a temperature-resistant and salt-resistant monomer and a cationic monomer in water, adding an initiator to carry out a polymerization reaction, and obtaining the inorganic gel polymerization inhibitor.

8. The preparation method according to claim 7, characterized in that: The polymerization temperature is 12-16°C; Preferably, the polymerization reaction time is 4 to 6 hours.

9. The preparation method according to claim 7 or 8, characterized in that: After the polymerization reaction is completed, the steps of granulation, drying and screening are also included.

10. Use of the inorganic gel polymerization inhibitor according to any one of claims 1 to 6 in the process of oil field development.

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