Adapt to the oilfield produced water with polymerization of the adhesive stock solution and its preparation method and application

Abstract

The present application relates to a kind of to be adapted to oilfield produced water polymerization's viscosity preservative stock solution and its preparation method and application.To be adapted to oilfield produced water polymerization's viscosity preservative stock solution, by the following components: zwitterionic surfactant 15-30%;Organic solvent 10-15%;Water 5-15%;Nitrite 0.1-0.3%;The rest is non-ionic surfactant.The preparation method includes: (1), the formula amount of non-ionic surfactant, zwitterionic surfactant organic solvent is added to reaction vessel, after stirring to obtain mixed solution;(2), the formula amount 50% to 70% of water is added to reaction vessel, after stirring to add the rest water and formula amount of nitrite, after stirring evenly to obtain viscosity preservative stock solution.To be adapted to oilfield produced water polymerization's viscosity preservative stock solution in the application of oil exploitation.The present application can greatly improve the injection viscosity of chemical flooding polymer, guarantee the formation sweeping capacity and oil displacement effect of chemical flooding oil system.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of petroleum engineering, and relates to oilfield polymer water treatment and polymer high-efficiency viscosity retention technology, in particular to a viscosity retention agent stock solution suitable for oilfield produced water polymer preparation, and a preparation method and application thereof. BACKGROUND

[0002] In the field of oil and gas field development, chemical flooding is an important means for improving the recovery rate of old oilfields with ultra-high water content.

[0003] At present, chemical flooding technology has been applied on a large scale in Daqing, Shengli, Dagang, Liaohe, Xinjiang and other oilfields, and the effect of reducing water and increasing oil and economic benefit in the field is remarkable. For example, Chinese patent application CN 113214815A (applicant: Daqing Yongzuo Petroleum Technology Development Co., Ltd.) discloses a kind of nano microemulsion oil displacement agent, which is composed of water, oil, surfactant, isopropyl alcohol and sodium chloride; wherein the volume ratio of oil to water is 0.8-0.9:1, the concentration of surfactant is 2.0-2.5wt% based on the total weight of oil and water, the concentration of isopropyl alcohol is 3.0-8.0wt%, and the concentration of sodium chloride is 2.0-5.5wt%; the surfactant is a combination of polyoxyethylene ether nonionic surfactant (Triton X) and sulfonated saponin. The nano microemulsion oil displacement agent of the present application belongs to a middle-phase microemulsion, which has a small particle size, the droplet size is about 20-50nm, the interfacial tension with oil and water can be reduced to 1.0×10 -4 mN / m or below, and can increase the oil recovery by at least 10 percentage points or more than water flooding. Chinese patent application CN1865392A (applicant: China Petroleum Sinopec Shengli Oilfield Branch Geological Science Research Institute) discloses a kind of high-efficiency complex oil displacement agent applied to tertiary oil recovery and a preparation method thereof, which is prepared by compounding petroleum sulfonate as the main surfactant with other nonionic surfactants, anionic surfactants, organic solvents and sodium chloride. Compared with the prior art, the high-efficiency complex oil displacement agent has the characteristics of effectively reducing the interfacial tension between oil and water, good compatibility with high salinity water, and the ability to reduce interfacial tension is not affected by salinity. The binary oil displacement system formed with polymer can increase the oil recovery by more than 20%.

[0004] One of the main mechanisms of chemical flooding is to inject high-viscosity polymer into the formation to reduce the water-oil mobility ratio, expand the swept volume and improve the oil recovery. At present, the commonly used oil displacement polymer in the field of chemical flooding is polyacrylamide high molecular polymer, which has the characteristics of good water solubility, good viscosity, good biodegradability, easy availability of raw materials and low price.

[0005] At present, the general method of oilfield polymer preparation is to prepare the mother liquor with clean water, and then dilute it with oilfield produced water. Because oilfield produced water generally contains reducing ions Fe 2+, sulfide and sulfate reducing bacteria, the sulfide is produced by the sulfate reducing bacteria reducing sulfate ions in water. When the reducing substances (such as reducing ions Fe 2+ , sulfide) in the oilfield produced water contact with the polymer mother liquor prepared with clean water, the reducing substances are prone to react with oxygen in the clean water to produce active free radicals, the active free radicals will attack the polymer molecular chain, break the molecular chain, reduce the polymerization degree, and finally result in a substantial reduction of the injection viscosity of the polymer, and further affect the chemical flooding effect.

[0006] The key to solving the above problems lies in preventing the reaction of reducing ions and oxygen to produce free radicals, inhibiting the chemical degradation of free radicals to the polymer, and improving the injection viscosity of the polymer in the injection well. There are two ways to solve the above problems at present:

[0007] Method 1: By exposing the water (oilfield produced water) to oxygen, the reducing substances in the oilfield produced water are oxidized, and the oxidized reducing substances no longer have reducing properties, so they cannot combine with oxygen to produce free radicals, thereby inhibiting the degradation of free radicals to the polymer. However, the exposure of the water to oxygen requires the construction of a large buffer tank, increases the ground construction, and the content of reducing substances in the produced water is unstable. Excessive exposure of oxygen will introduce more oxygen, resulting in poor long-term stability of the polymer in the formation, and insufficient exposure of oxygen will not completely remove the reducing substances, which will still combine with oxygen to produce free radicals to degrade the polymer

[0008] Method 2: By adding denitrifying bacteria to the oilfield produced water and adding a nutrient solution suitable for the bacteria, the growth of sulfate reducing bacteria is inhibited by biological competition and exclusion, thereby inhibiting the production of sulfide. However, the microbial competition method for removing sulfate reducing bacteria requires a certain reaction time, so a large buffer tank also needs to be constructed. In addition, the microbial competition method can only inhibit the production of sulfide, but cannot eliminate Fe 2+ . SUMMARY

[0009] The present application provides a kind of viscosity agent stock solution suitable for oilfield produced water polymerization, and its preparation method and application. 2+ 2+ The viscosity agent stock solution of the present application can kill bacteria and inhibit the production of sulfide in water, and it can also combine with free radicals produced in water to inhibit the attack of free radicals on the main chain of the polymer, thereby improving the injection viscosity of the polymer. ​

[0010] Technical solution: The preservative stock solution is suitable for oilfield produced water polymerization. Based on the total weight of the preservative stock solution, the preservative stock solution is composed of:

[0011]

[0012] The balance is a nonionic surfactant.

[0013] Further, the nonionic surfactant is composed of a free radical trapping agent and a complexing agent. Based on the total mass of the nonionic surfactant, the free radical trapping agent accounts for 50%-80%, and the balance is the complexing agent.

[0014] Further, the free radical trapping agent accounts for 60%-80%, and the balance is the complexing agent.

[0015] Further, the free radical trapping agent is at least one of decaglycerol monolaurate, hexaglycerol monolaurate, decaglycerol octanoate, hexaglycerol octanoate, decaglycerol monodecanoate, and hexaglycerol monodecanoate.

[0016] Further, the complexing agent is at least one of coconut oil diethanolamide, lauric acid diethanolamide, cocamide monoethanolamide, lauric acid monoethanolamide, oleic acid diethanolamide, and stearic acid diethanolamide.

[0017] Further, the zwitterionic surfactant is at least one of lauryl amide propyl hydroxy sulfobetaine, cocamide propyl hydroxy sulfobetaine, hexadecanamide propyl hydroxy propyl sulfobetaine, oleic acid amide propyl hydroxy sulfobetaine, and erucic acid amide propyl hydroxy sulfobetaine.

[0018] Further, the organic solvent is a polyhydroxy alcohol.

[0019] Further, the polyhydroxy alcohol is at least one of glycerol, ethylene glycol, pentaerythritol, trimethylolpropane, propylene glycol, dipropylene glycol, pentanediol, and hexanediol.

[0020] Further, the nitrite is at least one of sodium nitrite, potassium nitrite, and ammonium nitrite.

[0021] The above-mentioned preparation method of the preservative stock solution suitable for oilfield produced water polymerization includes the following steps:

[0022] (1) Add the formula amount of nonionic surfactant, the formula amount of zwitterionic surfactant, and the formula amount of organic solvent into a reaction container, and stir for at least 0.5 hours to obtain a mixed solution;

[0023] (2), the formula amount 50%-70% water is added to the reaction container, after stirring for at least 0.5h, the rest water and the formula amount of nitrite are added, and the viscosity agent stock solution is obtained after uniform stirring.

[0024] The viscosity agent stock solution adapted to the polymerization of oilfield produced water is applied in oil exploitation.

[0025] The viscosity agent stock solution prepared by the preparation method is applied in oil exploitation.

[0026] Further, the specific steps are as follows:

[0027] (1), the viscosity agent stock solution is added to the stirring tank, and the viscosity agent stock solution is uniformly stirred and reserved;

[0028] (2), the viscosity agent stock solution in the stirring tank is directly added to a certain amount of oilfield produced water, and the oilfield produced water with the viscosity agent is obtained after uniform stirring, wherein:

[0029] The mass ratio of the viscosity agent stock solution to the oilfield produced water is (0.06-0.24):1;

[0030] (3), the oilfield development polymer injection agent is obtained after the oilfield produced water with the viscosity agent obtained in step (2) and a certain concentration of polymer mother liquor are fully mixed, and then the oilfield development polymer injection agent is injected into the formation, wherein:

[0031] The mass concentration of the viscosity agent in the oilfield development polymer injection agent is 0.03%-0.12% based on the total mass of the oilfield development polymer injection agent.

[0032] Beneficial effects: the viscosity agent stock solution adapted to the polymerization of oilfield produced water and the preparation method and application thereof have the following beneficial effects:

[0033] (1), the present application can kill bacteria, inhibit the generation of sulfides in water, and also can combine with free radicals generated in water, inhibit the attack of free radicals on the polymer main chain, and improve the injection viscosity of the polymer;

[0034] (2), the raw materials involved are common chemical raw materials, easy to realize, low in addition concentration and cost;

[0035] (3), the use method is simple, a buffer tank does not need to be built, the land occupation is small, and the free radicals in water can be captured immediately after being added into the water (the capture of free radicals is a transient reaction), the reaction time is extremely short (the reaction time only needs millisecond level), and the injection viscosity of the polymer is greatly improved. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1The viscosity comparison diagram of the polymerization water (i.e. oilfield produced water) containing Fe 2+ The viscosity comparison diagram of the polymerization water (i.e. oilfield produced water) containing Fe

[0037] Figure 2 The viscosity comparison diagram of the polymerization water (i.e. oilfield produced water) containing Fe

[0038] Figure 3 The viscosity comparison diagram of the polymerization water (i.e. oilfield produced water) containing Fe 2+ , sulfide and sulfate reducing bacteria DETAILED DESCRIPTION

[0039] It should be noted that the following detailed description is exemplary in nature and is intended to provide further description of the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0040] It should be noted that the terms used herein are for the purpose of describing specific embodiments only and are not intended to limit exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form unless the context clearly indicates otherwise, and it should be further understood that the terms "comprise" and / or "include" as used herein specify the presence of features, steps, operations and / or combinations thereof.

[0041] At present, oilfield produced water is generally used to dilute the polymer mother liquor for polymerization in oilfields, and the oilfield produced water generally contains reducing ions Fe 2+ , sulfide and sulfate reducing bacteria. During the dilution of the polymer mother liquor, the reducing substances (such as reducing ions Fe 2+ and sulfide) in the oilfield produced water and the oxygen in the water undergo oxidation-reduction reaction to generate free radicals, which will degrade the polymer, resulting in a decrease in the injection viscosity, and seriously affecting the chemical flooding effect. The main technical scheme of the present application is as follows:

[0042] The viscosity comparison diagram of the polymerization water (i.e. oilfield produced water) containing Fe

[0043]

[0044] The balance is a non-ionic surfactant.

[0045] The preparation method of the above-mentioned viscosity stabilizer stock solution suitable for polymerization of oilfield produced water includes the following steps:

[0046] (1) adding the formula amount of nonionic surfactant, the formula amount of zwitterionic surfactant, and the formula amount of organic solvent into a reaction container, and stirring for at least 0.5 hours to obtain a mixed solution;

[0047] (2) adding the formula amount of 50%-70% water into the reaction container, stirring for at least 0.5 hours, then adding the remaining water and the formula amount of nitrite, and stirring uniformly to obtain the viscosity preservative stock solution.

[0048] The viscosity preservative stock solution suitable for oilfield produced water polymerization in the above application in oil exploitation.

[0049] The viscosity preservative stock solution suitable for oilfield produced water polymerization prepared by the preparation method in the above application in oil exploitation.

[0050] In order for those skilled in the art to have a clearer understanding of the technical solutions of the present application, the technical solutions of the present application will be described in detail below in combination with specific examples.

[0051] Example 1

[0052] The viscosity preservative stock solution suitable for oilfield produced water polymerization, based on the total weight of the viscosity preservative stock solution, is composed of the following components:

[0053]

[0054]

[0055] The balance is nonionic surfactant.

[0056] Further, the nonionic surfactant is composed of a radical trapping agent and a complexing agent, based on the total mass of the nonionic surfactant, the radical trapping agent accounts for 70%, and the balance is the complexing agent.

[0057] Still further, the radical trapping agent is a mixture of decaglycerol monolaurate and hexaglycerol monolaurate, and the mass ratio of the two is 20:15.56.

[0058] Still further, the complexing agent is a mixture of coconut oil diethanolamide and lauric acid diethanolamide, and the mass ratio of the two is 7.24:8.

[0059] Further, the zwitterionic surfactant is lauryl amide propyl hydroxyl sulfobetaine.

[0060] Further, the organic solvent is a polyhydroxy alcohol.

[0061] Still further, the polyhydroxy alcohol is a mixture of glycerol and ethylene glycol, and the mass ratio of the two is 7.6:6.4.

[0062] Further, the nitrite is sodium nitrite.

[0063] The preparation method of the above-mentioned base solution of the viscosity preservative adapted to polymerization of oilfield produced water includes the following steps:

[0064] (1) A formula amount of nonionic surfactant, a formula amount of zwitterionic surfactant, and a formula amount of organic solvent are added to a reaction container, and after stirring for 1 hour, a mixed solution is obtained;

[0065] (2) A formula amount of 60% water is added to the reaction container, and after stirring for 1 hour, the remaining water and a formula amount of nitrite are added, and after uniform stirring, the base solution of the viscosity preservative is obtained.

[0066] The above-mentioned base solution of the viscosity preservative adapted to polymerization of oilfield produced water is applied in oil exploitation.

[0067] The above-mentioned base solution of the viscosity preservative adapted to polymerization of oilfield produced water prepared by the preparation method is applied in oil exploitation.

[0068] Further, the specific steps are as follows:

[0069] (1) The base solution of the viscosity preservative is added to a stirring tank, and after uniform stirring, it is ready for use;

[0070] (2) The base solution of the viscosity preservative in the stirring tank is directly added to a certain amount of oilfield produced water, and after uniform stirring, the oilfield produced water with the viscosity preservative is obtained, wherein:

[0071] The mass ratio of the base solution of the viscosity preservative to the oilfield produced water is 0.2:1;

[0072] (3) The oilfield development polymer injection agent is obtained by fully mixing the oilfield produced water with the viscosity preservative obtained in step (2) and a polymer mother liquor with a certain concentration, and then the oilfield development polymer injection agent is injected into the formation, wherein:

[0073] The mass concentration of the viscosity preservative in the oilfield development polymer injection agent is 0.1% based on the total mass of the oilfield development polymer injection agent.

[0074] Example 2

[0075] The base solution of the viscosity preservative adapted to polymerization of oilfield produced water consists of the following components based on the total weight of the base solution of the viscosity preservative:

[0076]

[0077] The balance is nonionic surfactant.

[0078] Further, the non-ionic surfactant is composed of a radical capturing agent and a complexing agent, the radical capturing agent accounts for 80% and the complexing agent accounts for the rest, based on the total mass of the non-ionic surfactant.

[0079] Further, the radical capturing agent is a mixture of decaglycerin monolaurate and hexaglycerin monolaurate, and the mass ratio of the two is 21:14.56.

[0080] Further, the complexing agent is a mixture of coconut oil diethanolamide and lauric acid diethanolamide, and the mass ratio of the two is 5:10.24.

[0081] Further, the zwitterionic surfactant is cocamidopropyl hydroxysultaine.

[0082] Further, the organic solvent is a polyhydric alcohol.

[0083] Further, the polyhydric alcohol is a mixture of glycerol and ethylene glycol, and the mass ratio of the two is 7.5:6.5.

[0084] Further, the nitrite is potassium nitrite.

[0085] The preparation method of the above-mentioned proppant stock solution suitable for oilfield produced water polymerization includes the following steps:

[0086] (1) Add the formula amount of non-ionic surfactant, the formula amount of zwitterionic surfactant, and the formula amount of organic solvent into a reaction container, and stir for 2 hours to obtain a mixed solution;

[0087] (2) Add the formula amount of 70% water into the reaction container, stir for 2 hours, then add the remaining water and the formula amount of nitrite, and stir uniformly to obtain the proppant stock solution.

[0088] The above-mentioned proppant stock solution suitable for oilfield produced water polymerization is applied in oil exploitation.

[0089] The above-mentioned proppant stock solution suitable for oilfield produced water polymerization prepared by the preparation method is applied in oil exploitation.

[0090] Further, the specific steps are as follows:

[0091] (1) Put the proppant stock solution into a stirring tank, and stir uniformly for standby;

[0092] (2) Directly add the proppant stock solution in the stirring tank into a certain amount of oilfield produced water, and stir uniformly to obtain oilfield produced water with added proppant, wherein:

[0093] The mass ratio of the said viscosity agent stock solution to the said oilfield produced water is 0.24:1;

[0094] (3) The oilfield development polymer injection agent is obtained by mixing the oilfield produced water added with the viscosity agent and the polymer mother liquor with a certain concentration obtained in step (2), and then the oilfield development polymer injection agent is injected into the formation.

[0095] The mass concentration of the said viscosity agent in the said oilfield development polymer injection agent is 0.12% based on the total mass of the oilfield development polymer injection agent.

[0096] Example 3

[0097] The viscosity agent stock solution suitable for the polymerization of oilfield produced water, based on the total weight of the said viscosity agent stock solution, is composed of the following components:

[0098]

[0099] The rest is nonionic surfactant.

[0100] Further, the said nonionic surfactant is composed of a radical trapping agent and a complexing agent, and the said radical trapping agent accounts for 50% based on the total mass of the said nonionic surfactant, and the rest is the said complexing agent.

[0101] In another embodiment, the said radical trapping agent accounts for 60%-80%, and the rest is the said complexing agent.

[0102] Further, the said radical trapping agent is a mixture of decaglycerin monolaurate, hexaglycerin monolaurate, decaglycerin caprylate, hexaglycerin caprylate, decaglycerin monocaprate, and hexaglycerin monocaprate in equal mass ratio.

[0103] Further, the said complexing agent is a mixture of coconut oil diethanolamide, lauric acid diethanolamide, cocamide monoethanolamide, lauric acid monoethanolamide, oleic acid diethanolamide, and stearic acid diethanolamide in equal mass ratio.

[0104] Further, the said amphoteric surfactant is a mixture of lauryl amidopropyl hydroxysultaine, cocamidopropyl hydroxysultaine, cetyl amidopropyl hydroxypropyl sultaine, oleic acid amidopropyl hydroxysultaine, and erucic acid amidopropyl hydroxysultaine in equal mass ratio.

[0105] Further, the said organic solvent is a polyhydric alcohol.

[0106] Further, the said polyhydric alcohol is a mixture of glycerol, ethylene glycol, pentaerythritol, trimethylolpropane, propylene glycol, dipropylene glycol, pentylene glycol, and hexylene glycol in equal mass.

[0107] Further, the nitrite salt is a mixture of sodium nitrite, potassium nitrite, and ammonium nitrite in equal mass ratio.

[0108] In another embodiment, the nitrite salt is ammonium nitrite.

[0109] The preparation method of the above-mentioned base solution of the viscosity-maintaining agent adapted to polymerization of oilfield produced water comprises the following steps:

[0110] (1) adding a formula amount of nonionic surfactant, a formula amount of zwitterionic surfactant, and a formula amount of organic solvent into a reaction container, and stirring for 0.5 hours to obtain a mixed solution;

[0111] (2) adding a formula amount of 50% water into the reaction container, stirring for 0.5 hours, and then adding the remaining water and a formula amount of nitrite salt, and stirring uniformly to obtain the base solution of the viscosity-maintaining agent.

[0112] The above-mentioned base solution of the viscosity-maintaining agent adapted to polymerization of oilfield produced water is applied in oil exploitation.

[0113] The above-mentioned base solution of the viscosity-maintaining agent adapted to polymerization of oilfield produced water prepared by the preparation method is applied in oil exploitation.

[0114] Further, the specific steps are as follows:

[0115] (1) adding the base solution of the viscosity-maintaining agent into a stirring tank, and stirring uniformly for standby;

[0116] (2) directly adding the base solution of the viscosity-maintaining agent in the stirring tank into a certain amount of oilfield produced water, and stirring uniformly to obtain oilfield produced water with the viscosity-maintaining agent added, wherein:

[0117] the mass ratio of the base solution of the viscosity-maintaining agent to the oilfield produced water is 0.06:1;

[0118] (3) fully mixing the oilfield produced water with the viscosity-maintaining agent added obtained in step (2) and a polymer mother liquor with a certain concentration to obtain an oilfield development polymer injection agent, and then injecting the oilfield development polymer injection agent into a formation, wherein:

[0119] based on the total mass of the oilfield development polymer injection agent, the mass concentration of the viscosity-maintaining agent in the oilfield development polymer injection agent is 0.03%.

[0120] Examples 4-10

[0121] The same as Example 1, except that the free radical scavenger and / or complexing agent is different:

[0122]

[0123] Examples 11-19

[0124] The same as Example 1, except that the polyhydroxy alcohol is different:

[0125]

[0126]

[0127] Verification Example:

[0128] Example 20

[0129] This example is mainly used to illustrate the use method and use effect of the prepared polymerization-adapted viscosity preservative stock solution for oilfield produced water polymerization in Shengli Oilfield Shengli Oil Production Plant, which only contains Fe 2+ at the time.

[0130] The specific application steps are as follows:

[0131] (1) Take the prepared polymerization-adapted viscosity preservative stock solution for oilfield produced water polymerization obtained in Example 1, and add it to a stirring tank with a capacity of 1.6 m 3 L, and fully stir to make it uniform.

[0132] (2) Use a booster pump to directly add the high-efficiency viscosity preservative stock solution to the polymerization water (Fe 2+ content of 8 mg / L) in Shengli Oil Production Plant.

[0133] (3) Mix the high-pressure water with added viscosity preservative and the 5000 mg / L polymer stock solution after pressure boosting, and the mixed polymer concentration is 0.25%, and the viscosity preservative concentration is 0.04%.

[0134] (4) Test the viscosity of the polymer after adding the viscosity preservative, and compare it with the viscosity of the polymer without adding the viscosity preservative. The comparison results are shown in Figure 1 .

[0135] From the comparison results of Figure 1 , it can be seen that after adding the viscosity preservative, the mixed polymer viscosity is increased from 16.5 mPa·s to 47.5 mPa·s. Therefore, adding the viscosity preservative can inhibit the degradation of the polymer in the presence of Fe 2+ , and improve the injection viscosity.

[0136] Example 21

[0137] This example is mainly used to illustrate the use method and use effect of the prepared polymerization-adapted viscosity preservative stock solution for oilfield produced water polymerization in Shengli Oilfield Shengli Oil Production Plant, which only contains Fe at the time.

[0138] The specific application steps are as follows:

[0139] (1) Take the prepared viscosity preservative stock solution suitable for oilfield produced water polymerization to a 1.5m 3 capacity stirred tank, and fully stir to uniform.

[0140] (2) Use a booster pump to directly add the high-efficiency viscosity preservative stock solution to the polymerization water in the Gudong oil production plant (the polymerization water has a sulfide content of 2.3 mg / L and a sulfate-reducing bacteria content of 700 / mL).

[0141] (3) Mix the high-pressure water with the added viscosity preservative and the 5000 mg / L polymer stock solution after boosting, and the mixed polymer concentration is 0.24%, and the viscosity preservative concentration is 0.05%.

[0142] (4) Test the polymer viscosity after adding the viscosity preservative, and compare it with the polymer viscosity without adding the viscosity preservative. The comparison results are shown in Figure 2 .

[0143] From the comparison results in Figure 2 , after adding the viscosity preservative, the mixed polymer viscosity is increased from 22.5 mPa·s to 67.5 mPa·s. Therefore, adding the viscosity preservative can inhibit the degradation of the polymer in the presence of sulfides and sulfate-reducing bacteria, and increase the injection viscosity.

[0144] Example 22

[0145] This example is mainly used to illustrate the use method and use effect of the viscosity preservative stock solution suitable for oilfield produced water polymerization of the polymerization of the present application when simultaneously containing Fe 2+ , sulfides and sulfate-reducing bacteria in the Gudao oil production plant of Shengli oilfield.

[0146] The specific application steps are as follows:

[0147] (1) Take the prepared viscosity preservative stock solution suitable for oilfield produced water polymerization to a 1.5m 3 capacity stirred tank, and fully stir to uniform.

[0148] (2) Use a booster pump to directly add the viscosity preservative stock solution suitable for oilfield produced water polymerization to the polymerization water in the Gudao oil production plant (the polymerization water has a Fe 2+ content of 8.8 mg / L, a sulfide content of 1.2 mg / L, and a sulfate-reducing bacteria content of 600 / mL).

[0149] (3) Mix the high-pressure water with the added viscosity preservative and the 5000 mg / L polymer stock solution after boosting, and the mixed polymer concentration is 0.25%, and the viscosity preservative concentration is 0.06%.

[0150] (4) Test the viscosity of the polymer after adding the adhesive and compare it with the viscosity of the polymer without adding the adhesive. Figure 3 shown.

[0151] Depend on Figure 3 The comparison results show that after adding the adhesive, the viscosity of the polymer mixture increased from 18.5mPa·s to 76.6mPa·s. Therefore, adding the adhesive can simultaneously inhibit the 2+ , the degradation of polymers in the presence of sulfide and sulfate-reducing bacteria increases the injection viscosity.

[0152] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A stick agent stock solution adapted to the polymerization of oilfield produced water, characterized in that, The total weight of the adhesive preservative stock solution is based on the following components: The balance is a non-ionic surfactant, wherein: The non-ionic surfactant is composed of a free radical trapping agent and a complexing agent, the free radical trapping agent accounts for 50%-80% based on the total mass of the non-ionic surfactant, and the balance is the complexing agent; The free radical trapping agent is at least one of decaglycerol monolaurate, hexaglycerol monolaurate, decaglycerol octanoate, hexaglycerol octanoate, decaglycerol monomyristate, and hexaglycerol monomyristate; The complexing agent is at least one of coconut oil diethanolamide, lauric acid diethanolamide, coconut amide monoethanolamide, lauric acid monoethanolamide, oleic acid diethanolamide, and stearic acid diethanolamide.

2. The stick agent stock solution adapted to the polymerization of oilfield produced water according to claim 1, characterized in that, The free radical trapping agent accounts for 60%-80%, and the balance is the complexing agent.

3. The stick agent stock solution adapted to the polymerization of oilfield produced water of claim 1, wherein, The zwitterionic surfactant is at least one of lauryl amide propyl hydroxy sulfobetaine, coconut amide propyl hydroxy sulfobetaine, hexadecanoyl amide propyl hydroxy propyl sulfobetaine, oleic acid amide propyl hydroxy sulfobetaine, and erucic acid amide propyl hydroxy sulfobetaine.

4. The stickwater fluidizing agent stock solution adapted for oilfield produced water polymer flocculation of claim 1, wherein, The organic solvent is a polyhydroxy alcohol.

5. The SP-SP solution adapted to the polymerization of oilfield produced water according to claim 4, characterized in that, The polyhydroxy alcohol is at least one of glycerol, ethylene glycol, pentaerythritol, trimethylolpropane, propylene glycol, dipropylene glycol, pentanediol, and hexanediol.

6. The stickwater fluidizing agent stock solution adapted for oilfield produced water polymer flocculation of claim 1, wherein, The nitrite is at least one of sodium nitrite, potassium nitrite, and ammonium nitrite.

7. The preparation method of the adhesive preservative stock solution suitable for polymerization of oilfield produced water according to any one of claims 1-6, comprising the following steps: (1) adding the formula amount of non-ionic surfactant, the formula amount of zwitterionic surfactant, and the formula amount of organic solvent into a reaction container, stirring for at least 0.5 hours to obtain a mixed solution; (2) adding the formula amount of 50%-70% water into the reaction container, stirring for at least 0.5 hours, then adding the remaining water and the formula amount of nitrite, and stirring uniformly to obtain the adhesive preservative stock solution.

8. The application of the adhesive preservative stock solution suitable for polymerization of oilfield produced water according to any one of claims 1-6 in oil exploitation.

9. The application of the adhesive preservative stock solution suitable for polymerization of oilfield produced water prepared by the preparation method of claim 7 in oil exploitation.

10. Use according to claim 8 or 9, characterized in that, The specific steps are as follows: (1) adding the adhesive preservative stock solution into a stirring tank, and stirring uniformly for standby; (2) directly adding the adhesive preservative stock solution in the stirring tank into a certain amount of oilfield produced water, and stirring uniformly to obtain oilfield produced water with added adhesive preservative, wherein: The mass ratio of the adhesive preservative stock solution to the oilfield produced water is (0.06-0.24):1; (3) fully mixing the oilfield produced water with added adhesive preservative obtained in step (2) and a certain concentration of polymer mother liquor to obtain an oilfield development polymer injection agent, and then injecting the oilfield development polymer injection agent into a formation, wherein: The mass concentration of the adhesive preservative in the oilfield development polymer injection agent is 0.03%-0.12% based on the total mass of the oilfield development polymer injection agent.

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