Liquid high-temperature-resistant iron ion stabilizer for acidification and preparation method thereof

Abstract

The application belongs to the technical field of oil exploitation, and particularly relates to a liquid high-temperature-resistant iron ion stabilizer for acidification and a preparation method thereof. The preparation method is as follows: 4-morpholinopiperidine, dichloroether and isopropyl alcohol are added into a four-necked flask provided with a condenser, stirred and dissolved, heated, and kept for reaction at pH 7.5-8; ethylenediaminetriacetic acid is added into the above mixture, kept for reaction at pH 7.5-8, heated, and kept for reaction; vacuum distillation is carried out, glutamic acid is added, pH is adjusted to 5.5-6, and the product iron ion stabilizer is obtained. The iron ion stabilizer has the advantages of high-temperature resistance and good iron ion stabilizing effect, and the stable iron ion capacity is above 100 mg / ml; after constant temperature at 160 DEG C for 4 h, the stable iron ion retention rate is above 97%.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of oil exploitation, and particularly relates to a liquid high-temperature-resistant iron ion stabilizer for acidification and a preparation method thereof. BACKGROUND

[0002] In oilfield development, acidification is one of the main measures for stable production and yield increase of oil and gas wells, stable injection and injection increase of water injection wells. It is to remove the pollution near the bottom of production wells and water injection wells by using acid liquid, restore the permeability of the formation or dissolve the cement of the formation rock to improve the permeability of the formation, dredge the fluid seepage channel, and thus restore and improve the productivity of the well.

[0003] During the acidification process, the acid liquid reacts with the surface equipment, downhole string and iron-containing mineralization in the formation, and Fe 3+ and Fe 2+ are inevitably produced. With the continuous reaction of the acid liquid with the formation, the pH value of the acid liquid continuously rises. When the pH value of the acid liquid rises to 2.2, Fe 3+ starts to produce flocculent Fe(OH)3precipitate. When the pH value of the acid liquid rises to 3.2, if an effective iron ion stabilizer is not used, all the dissolved trivalent iron will precipitate, causing secondary pollution to the formation and serious plugging of the newly opened flow channels by the acidification construction. In addition, the iron ion can also enhance the stability of the residual acid emulsion, bring difficulties to the acid discharge, and intensify the production of acid sludge, causing new damage to the oil layer.

[0004] In order to prevent the secondary precipitation of iron from plugging the oil and gas seepage channels in the formation and causing the reduction of recovery rate, people began to add iron ion stabilizers to the acidification working liquid to reduce the generation of precipitates.

[0005] The iron ion stabilizer can prevent the reprecipitation of Fe 3+ from multiple aspects such as complexation, coordination, reduction and dispersion, prevent formation damage, and improve the yield increase effect of acidification operation.

[0006] CN105295887A discloses an iron ion stabilizer for acidification operation with excellent performance and a preparation method thereof. During the acidification process, H +The concentration is continuously reduced, and the pH value is continuously increased, so that the originally existing iron in an ionic state begins to precipitate, blocks the oil and gas seepage channel in the formation, causes secondary pollution, and reduces the recovery rate, and thus iron ion stabilizer needs to be added to make the iron exist in a soluble state in the residual acid. The technical scheme of the acidification liquid high-temperature-resistant iron ion stabilizer comprises the following steps: adding sodium erythorbate, NTA, citric acid, EDTA disodium salt and water into a container in proportion, the mass fraction of each component is as follows: sodium erythorbate 5%-16%, NTA 1%-3%, citric acid 2%-5%, EDTA disodium salt 2%-5%, and the balance is water; a certain temperature is controlled and stirring is performed to completely dissolve, and then cooling to room temperature, transferring to a volumetric flask and constant volume, and the iron ion stabilizer is obtained. The iron ion stabilizer has chelating ability and reducing ability, has strong iron stabilizing ability, and has low production cost. However, the iron ion stabilizing capacity of the iron ion stabilizer is only about 40 mg / ml, and the iron ion stabilizing capacity is low.

[0007] CN103436247A discloses a water injection augmented acidification liquid. The formula of the acidification liquid is as follows: (10-14%) hydrochloric acid, (1-4%) hydrofluoric acid, (1-4%) acidification retarder, (1-2%) acidification corrosion inhibitor, (0.1-0.5%) iron ion stabilizer, (0.2-1%) demulsification and cleanup agent, (1-2%) clay stabilizer and (72.5-85.7%) water. The acidification liquid adds the acidification retarder, can prolong the acid rock reaction time, increase the effective action distance of active acid, improve the acidification efficiency, and can achieve the purpose of deep acidification. The conventional mud acid and the formation mineral reaction rate is fast, and the near wellbore zone is excessively eroded, and the deep acidification problem cannot be solved. The main principle of the acidification liquid is to slow down the corrosion of the metal iron to reduce the Fe(OH)3 precipitation, and the generated Fe(OH)3 is stable in the acidification liquid. 3+ The stabilizing effect is poor. SUMMARY

[0008] The acidification liquid high-temperature-resistant iron ion stabilizer has the advantages of high-temperature resistance and good iron ion stabilizing effect, and the stable iron ion capacity is above 100 mg / ml; after 4 h of constant temperature at 160 DEG C, the stable iron ion retention rate is above 97%.

[0009] One of the purposes of the present application discloses an acidification liquid high-temperature-resistant iron ion stabilizer, and the molecular structure formula of the iron ion stabilizer is as follows:

[0010]

[0011] Another purpose of the present application discloses a preparation method of the acidification liquid high-temperature-resistant iron ion stabilizer, and the specific steps of the preparation method are as follows:

[0012] (1) Add 4-morpholinopyridine, dichloroethyl ether and isopropanol to a four-necked flask equipped with a condenser, stir to dissolve, heat to 55-60℃, keep the temperature for 1-2 hours, add sodium hydroxide solution several times during the process to maintain pH 7.5-8.

[0013] (2) Add ethylenediaminetriacetic acid to the above mixture, adjust and maintain the pH at 7.5-8 with sodium hydroxide solution, heat to 65-70℃, and keep the reaction at this temperature for 2-4 hours;

[0014] (3) Reduced pressure distillation, leaving a small amount of isopropanol, add glutamic acid, adjust the pH to 5.5-6 with sodium hydroxide solution to obtain the product iron ion stabilizer.

[0015] Preferably, based on 1 mole of 4-morpholinopyridine, the amounts of dichloroethyl ether and ethylenediaminetriacetic acid are 0.8-1.4 and 0.8-1.2 moles, respectively; more preferably, based on 1 mole of 4-morpholinopyridine, the amounts of dichloroethyl ether and ethylenediaminetriacetic acid are 1-1.2 and 0.9-1.1 moles, respectively.

[0016] Preferably, in step (1), the weight ratio of isopropanol to 4-morpholinopyridine is 8-10:1.

[0017] Preferably, in step (3), the weight ratio of the small amount of isopropanol to 4-morpholinopyridine is 2-2.5:1.

[0018] Preferably, in step (3), the weight ratio of glutamic acid to 4-morpholinopyridine is 0.5-1.5:1.

[0019] The synthesis reaction equation for the liquid high-temperature resistant iron ion stabilizer for acidification in this invention is as follows:

[0020]

[0021] The acidification liquid high-temperature resistant iron ion stabilizer of this invention has three types of functional groups. The carboxylic acid functional group has a chelating effect, which can chelate iron ions and significantly reduce free iron ions, thereby reducing the possibility of iron ions precipitating from the solution. The tertiary amine contains lone pairs of electrons, which can form coordinate bonds with iron ions, further reducing free iron ions. The tertiary amine and oxygen in morpholine piperidine contain lone pairs of electrons, which can form coordinate bonds with iron ions, further reducing free iron ions. Glutamic acid is relatively inexpensive and plays an auxiliary role in the product. Its mechanism of action is to reduce free iron ions through carboxyl chelation and amino coordination.

[0022] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0023] (1) The acidification liquid high-temperature resistant iron ion stabilizer of the present invention has a strong ability to stabilize iron ions, reaching more than 100 mg / ml;

[0024] (2) The acidification liquid high-temperature resistant iron ion stabilizer of the present invention has strong temperature resistance. After being kept at 160°C for 4 hours, the stable iron ion retention rate reaches more than 97%. Detailed Implementation

[0025] The technical solution of the present invention will be further described below with reference to specific embodiments:

[0026] Example 1

[0027] (1) Add 0.2 mol 4-morpholinopyridine, 0.16 mol dichloroethyl ether, and 272 g isopropanol to a four-necked flask equipped with a condenser, stir to dissolve, heat to 55°C, and keep the reaction at this temperature for 2 hours. During this period, sodium hydroxide solution is added several times to maintain the pH at 7.5-8.

[0028] (2) Add 0.16 mol of ethylenediaminetriacetic acid to the above mixture, adjust and maintain the pH at 7.5-8 with sodium hydroxide solution, heat to 65°C, and keep the reaction at this temperature for 4 hours;

[0029] (3) Reduced pressure distillation, the remaining 81g of isopropanol, 17g of glutamic acid, and the pH was adjusted to 5.5-6 with sodium hydroxide solution to obtain the product iron ion stabilizer.

[0030] Example 2

[0031] (1) Add 0.2 mol 4-morpholinopyridine, 0.28 mol dichloroethyl ether and 340 g isopropanol to a four-necked flask equipped with a condenser, stir to dissolve, heat to 60°C, keep the temperature for 1 h, add sodium hydroxide solution several times during the process to maintain pH 7.5-8;

[0032] (2) Add 0.24 mol of ethylenediaminetriacetic acid to the above mixture, adjust and maintain the pH at 7.5-8 with sodium hydroxide solution, heat to 70°C, and keep the reaction at this temperature for 3 hours;

[0033] (3) Reduced pressure distillation, the remaining 85g isopropanol, add 19.8g glutamic acid, adjust the pH to 5.5-6 with sodium hydroxide solution to obtain the product iron ion stabilizer.

[0034] Example 3

[0035] (1) Add 0.2 mol 4-morpholinopyridine, 0.18 mol dichloroethyl ether and 296 g isopropanol to a four-necked flask equipped with a condenser, stir to dissolve, heat to 57°C, keep warm for 1.5 h, add sodium hydroxide solution several times during the process to maintain pH 7.5-8;

[0036] (2) Add 0.17 mol of ethylenediaminetriacetic acid to the above mixture, adjust and maintain the pH at 7.5-8 with sodium hydroxide solution, heat to 66°C, and keep the reaction at this temperature for 2.5 h;

[0037] (3) Reduced pressure distillation, the remaining 80g of isopropanol, 26.4g of glutamic acid, and the pH was adjusted to 5.5-6 with sodium hydroxide solution to obtain the product iron ion stabilizer.

[0038] Example 4

[0039] (1) Add 0.2 mol 4-morpholinopyridine, 0.26 mol dichloroethyl ether, and 332 g isopropanol to a four-necked flask equipped with a condenser, stir to dissolve, heat to 58°C, and keep the reaction at this temperature for 1.8 h. During this period, sodium hydroxide solution is added several times to maintain the pH at 7.5-8.

[0040] (2) Add 0.23 mol of ethylenediaminetriacetic acid to the above mixture, adjust and maintain the pH at 7.5-8 with sodium hydroxide solution, heat to 65°C, and keep the reaction at this temperature for 4 hours;

[0041] (3) Reduced pressure distillation, the remaining 83g isopropanol, add 31.8g glutamic acid, adjust the pH to 5.5-6 with sodium hydroxide solution to obtain the product iron ion stabilizer.

[0042] Example 5

[0043] (1) Add 0.2 mol 4-morpholinopyridine, 0.19 mol dichloroethyl ether, and 283 g isopropanol to a four-necked flask equipped with a condenser, stir to dissolve, heat to 60°C, and keep the reaction at this temperature for 1.5 h. During this period, sodium hydroxide solution is added several times to maintain the pH at 7.5-8.

[0044] (2) Add 0.18 mol of ethylenediaminetriacetic acid to the above mixture, adjust and maintain the pH at 7.5-8 with sodium hydroxide solution, heat to 70°C, and keep the reaction at this temperature for 2 hours;

[0045] (3) Reduced pressure distillation, the remaining 76g of isopropanol, 34.7g of glutamic acid, and pH adjusted to 5.5-6 with sodium hydroxide solution to obtain the product iron ion stabilizer.

[0046] Example 6

[0047] (1) Add 0.2 mol 4-morpholinopyridine, 0.25 mol dichloroethyl ether, and 314 g isopropanol to a four-necked flask equipped with a condenser, stir to dissolve, heat to 55°C, and keep the reaction at this temperature for 2 hours. During this period, sodium hydroxide solution is added several times to maintain the pH at 7.5-8.

[0048] (2) Add 0.22 mol of ethylenediaminetriacetic acid to the above mixture, adjust and maintain the pH at 7.5-8 with sodium hydroxide solution, heat to 65°C, and keep the reaction at this temperature for 4 hours;

[0049] (3) Reduced pressure distillation, the remaining 73g isopropanol, 41.4g glutamic acid, and pH adjusted to 5.5-6 with sodium hydroxide solution to obtain the product iron ion stabilizer.

[0050] Example 7

[0051] (1) Add 0.2 mol 4-morpholinopyridine, 0.2 mol dichloroethyl ether, and 300 g isopropanol to a four-necked flask equipped with a condenser, stir to dissolve, heat to 58°C, and keep the reaction at this temperature for 1.8 h. During this period, sodium hydroxide solution is added several times to maintain the pH at 7.5-8.

[0052] (2) Add 0.19 mol of ethylenediaminetriacetic acid to the above mixture, adjust and maintain the pH at 7.5-8 with sodium hydroxide solution, heat to 69°C, and keep the reaction at this temperature for 4 hours;

[0053] (3) Reduced pressure distillation, the remaining 70g isopropanol, add 46.8g glutamic acid, adjust the pH to 5.5-6 with sodium hydroxide solution to obtain the product iron ion stabilizer.

[0054] Example 8

[0055] (1) Add 0.2 mol 4-morpholinopyridine, 0.23 mol dichloroethyl ether, and 323 g isopropanol to a four-necked flask equipped with a condenser, stir to dissolve, heat to 59°C, and keep the reaction at this temperature for 1 hour. During this period, sodium hydroxide solution is added several times to maintain the pH at 7.5-8.

[0056] (2) Add 0.21 mol of ethylenediaminetriacetic acid to the above mixture, adjust and maintain the pH at 7.5-8 with sodium hydroxide solution, heat to 67°C, and keep the reaction at this temperature for 2 hours;

[0057] (3) Reduced pressure distillation, the remaining 68g of isopropanol, 50.5g of glutamic acid, and pH adjusted to 5.5-6 with sodium hydroxide solution to obtain the product iron ion stabilizer.

[0058] Example 9

[0059] (1) Add 0.2 mol 4-morpholinopyridine, 0.22 mol dichloroethyl ether, and 315 g isopropanol to a four-necked flask equipped with a condenser, stir to dissolve, heat to 57°C, and keep the reaction at this temperature for 1.5 h. During this period, sodium hydroxide solution is added several times to maintain the pH at 7.5-8.

[0060] (2) Add 0.2 mol of ethylenediaminetriacetic acid to the above mixture, adjust and maintain the pH at 7.5-8 with sodium hydroxide solution, heat to 70°C, and keep the reaction at this temperature for 2 hours;

[0061] (3) Reduced pressure distillation, the remaining 70g isopropanol, 51g glutamic acid, and pH adjusted to 5.5-6 with sodium hydroxide solution to obtain the product iron ion stabilizer.

[0062] Test Example 1

[0063] The iron ion stabilizer of the present invention (Examples 1-9) was tested for its ability to stabilize iron ions (N1). The evaluation method was based on SY / T6571-2012 "Performance Evaluation Method of Iron Ion Stabilizer for Acidification".

[0064] A comparative experiment was conducted using the iron ion stabilizer for acidification from Jinan Beiyate Chemical Technology Co., Ltd. (Comparative Example 1) and the high-temperature iron ion stabilizer for acidification from Jinan Quanxing New Materials Co., Ltd. (Comparative Example 2).

[0065] As can be seen from Table 1, the iron ion stabilizers of the present invention (Examples 1-9) all have an iron ion stabilization capacity of over 100 mg / ml, with the highest reaching 136 mg / ml (Example 8). In contrast, the iron ion stabilization capacities of the comparative examples, namely the iron ion stabilizer for acidification from Jinan Beiyate Chemical Technology Co., Ltd. (Comparative Example 1) and the high-temperature iron ion stabilizer for acidification from Jinan Quanxing New Materials Co., Ltd. (Comparative Example 2), are 69 mg / ml and 82 mg / ml, respectively, which are significantly lower than those of the present invention.

[0066] Test Example 2

[0067] The iron ion stabilizer of the present invention (Examples 1-9) was tested for its ability to stabilize iron ions (N2) at high temperature. The evaluation method referred to SY / T 6571-2012 "Performance Evaluation Method for Iron Ion Stabilizers for Acidification". The method in section 6.2 of the standard was followed. Stabilizer samples were prepared, placed in an oven at 160℃ for 4 hours, and then removed. The iron ion stabilization ability (N2) was tested according to the method in the standard. 2。

[0068] A comparative experiment was conducted using the iron ion stabilizer for acidification from Jinan Beiyate Chemical Technology Co., Ltd., and the high-temperature iron ion stabilizer for acidification from Jinan Quanxing New Materials Co., Ltd.

[0069] Calculate the high-temperature stable iron ion retention rate S.

[0070] S = (N2 / N1) × 100%

[0071] Test results of the ability to stabilize iron ions at room temperature and 160℃

[0072]

[0073]

[0074] As shown in Table 1, the high-temperature resistant liquid iron ion stabilizer for acidification of the present invention (Examples 1-9) maintained a stable iron ion retention rate of over 97% after being kept at 160℃ for 4 hours, with the highest reaching 99.3%. In contrast, the stable iron ion retention rates of the comparative iron ion stabilizers from Jinan Beiyate Chemical Technology Co., Ltd. and Jinan Quanxing New Materials Co., Ltd. for acidification were 88.4% and 93.9%, respectively, significantly lower than those of the present invention. The high-temperature resistant liquid iron ion stabilizer for acidification of the present invention exhibits strong temperature resistance.

[0075] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing a liquid high-temperature resistant iron ion stabilizer for acidification, characterized in that, The specific steps of the preparation method are as follows: (1) Add 4-morpholinopyridine, dichloroethyl ether and isopropanol to a four-necked flask equipped with a condenser, stir to dissolve, heat to 55-60℃, keep the temperature for 1-2 hours, add sodium hydroxide solution several times during the process, and maintain pH 7.5-8. (2) Add ethylenediaminetriacetic acid to the above mixture, adjust and maintain the pH at 7.5-8 with sodium hydroxide solution, heat to 65-70℃, and keep the reaction at this temperature for 2-4 hours; (3) Vacuum distillation, with a small amount of isopropanol remaining, add glutamic acid, and adjust the pH to 5.5-6 with sodium hydroxide solution to obtain the product iron ion stabilizer; The molecular structure of the iron ion stabilizer is as follows: 。 2. The method for preparing a liquid high-temperature resistant iron ion stabilizer for acidification according to claim 1, characterized in that, Based on 1 mole of 4-morpholinopyridine, the amounts of dichloroethyl ether and ethylenediaminetriacetic acid are 0.8-1.4 and 0.8-1.2 moles, respectively.

3. The method for preparing a liquid high-temperature resistant iron ion stabilizer for acidification according to claim 2, characterized in that, Based on 1 mole of 4-morpholinopyridine, the amounts of dichloroethyl ether and ethylenediaminetriacetic acid are 1-1.2 and 0.9-1.1 moles, respectively.

4. The preparation method of the liquid high-temperature resistant iron ion stabilizer for acidification according to claim 1, characterized in that, In step (1), the weight ratio of isopropanol to 4-morpholinopyridine is 8-10:

1.

5. The method for preparing a liquid high-temperature resistant iron ion stabilizer for acidification according to claim 1, characterized in that, In step (3), the weight ratio of the small amount of isopropanol to 4-morpholinopyridine is 2-2.5:

1.

6. The method for preparing a liquid high-temperature resistant iron ion stabilizer for acidification according to claim 1, characterized in that, In step (3), the weight ratio of glutamic acid to 4-morpholinopyridine is 0.5-1.5:

1.

7. A liquid high-temperature resistant iron ion stabilizer for acidification, characterized in that, The molecular structure of the iron ion stabilizer is as follows: 。

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