Oil-based drilling cuttings oil washing agent, preparation method thereof and oil washing method

Abstract

The application provides a novel oil-based drilling cuttings oil washing agent and a preparation method and an oil washing method thereof. The preparation method of the oil washing agent comprises the following steps: (1) mixing 3-dimethylaminopropylamine or diethylamine with a first solvent, adding perfluoroalkylsulfonyl fluoride or perfluoroalkyl acyl fluoride dropwise under an ice water bath, reacting at 30-60 DEG C for 2-4 hours, removing the solvent, and generating a fluorine-containing intermediate; (2) mixing the fluorine-containing intermediate with a second solvent at 60-90 DEG C, adding 3-chloro-2-hydroxypropane sulfonate sodium salt, sodium chloroacetate or 2-chloroethyl sulfonate sodium, adjusting the pH to be under alkaline conditions, and reacting for 5-12 hours to obtain a fluorine-containing amphoteric ion type oil washing agent. The oil washing agent can exert a good oil washing effect while avoiding the formation of oil-water emulsion, and the preparation method is simple, convenient, fast, efficient, and low in cost.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of oilfield chemicals, and particularly relates to a novel oil-based drilling cuttings oil washing agent as well as a preparation method and an oil washing method thereof. BACKGROUND

[0002] With the vigorous exploration and development of shale gas reservoirs, the use scale of oil-based drilling fluids in the drilling process is increasing, and the amount of oil-based drilling cuttings is increasing year by year, which has become a huge environmental and safety hidden danger. Because the oil-based drilling cuttings have high dispersity, small particle size (micron level), large specific surface area and strong surface adsorption capacity, it is difficult to separate fine drilling cuttings from oil and water. Therefore, a series of fluorine-containing amphoteric ion type oil washing agents are synthesized. Compared with anionic and cationic oil washing agents, the amphoteric oil washing agent has good hard water resistance, interfacial activity stability, temperature stability and biological degradation resistance, and although the price is higher, its application is still expanding.

[0003] At present, most oil washing agents are hydrocarbon oil washing agents. Because the surface activity of the hydrocarbon oil washing agent is lower than that of fluorocarbon active agent, the use amount of the hydrocarbon demulsifier solvent is large, the hydrocarbon demulsifier solvent is volatile, has toxicity and high cost, and therefore the fluorine-containing oil washing agent is also a development trend. The fluorine-containing oil washing agent has high surface activity, high thermal stability, high chemical stability and oil and water repellency due to the unique carbon-fluorine bond, and has extremely high research value. A good oil washing agent needs to have strong interfacial activity and strong performance of reducing oil-water interfacial tension. The fluorine-containing oil washing agent has the unique performance of "three high" and "two repellent", so it has more excellent oil washing effect than other oil washing agents.

[0004] In view of this, a series of fluorine-containing amphoteric ion type "oleophobic and hydrophobic" oil washing agents are synthesized, which have high drilling cuttings surface adsorption and high surface activity. Compared with the prior art, the oil washing agent has the characteristics of small amount, fast oil washing speed and avoidance of oil-water emulsification, and is a high-efficiency and fast oil washing agent. SUMMARY

[0005] To solve the above technical problems, the purpose of the present application is to provide a fluorine-containing amphoteric ion type oil washing agent and a preparation method thereof. The oil washing agent can exert good oil washing effect while avoiding the formation of oil-water emulsion, and the preparation method is simple, convenient, fast, efficient and low in cost.

[0006] To achieve the above purpose, the present application provides a preparation method of a fluorine-containing amphoteric ion type oil washing agent, which comprises the following steps:

[0007] (1) 3-dimethylaminopropylamine or diethylamine is mixed with a first solvent, and perfluoroalkylsulfonyl fluoride or perfluoroalkyl acyl fluoride is added dropwise under an ice water bath, and reacted at 30-60 DEG C for 2-4 hours, and the solvent is removed to generate a fluorine-containing intermediate;

[0008] (2) mixing the fluorine-containing intermediate with a second solvent at 60-90°C, adding 3-chloro-2-hydroxypropane sulfonic acid sodium salt, sodium chloroacetate or 2-chloroethyl sulfonic acid sodium salt, adjusting pH (preferably using sodium hydroxide) to alkaline condition (preferably pH=8-9) and reacting for 5-12 hours to obtain a fluorine-containing amphoteric surfactant.

[0009] In the above preparation method, preferably, the perfluoroalkylsulfonyl fluoride is C n F 2n+1 SO2F, n=2-10.

[0010] In the above preparation method, preferably, the perfluoroalkylsulfonyl fluoride is C m F 2m+1 COF, m=2-10.

[0011] In the above preparation method, preferably, in step (1), the molar ratio of the perfluoroalkylsulfonyl fluoride or perfluoroalkylacyl fluoride, 3-dimethylamino propylamine or diethylamine is 1:1-3, more preferably 1:2.

[0012] In the above preparation method, preferably, in step (2), the molar ratio of the fluorine-containing intermediate to the 3-chloro-2-hydroxypropane sulfonic acid sodium salt, sodium chloroacetate or 2-chloroethyl sulfonic acid sodium salt is 1:1-2.

[0013] In the above preparation method, preferably, step (1) comprises mixing 3-dimethylamino propylamine with a first solvent, adding perfluoroalkylsulfonyl fluoride dropwise under ice water bath, reacting at 30-60°C for 2-4 hours (preferably 3 hours), and removing the solvent to obtain the fluorine-containing intermediate.

[0014] In the above preparation method, preferably, in step (1), the first solvent comprises one or a combination of two or more of diethyl ether, isopropyl ether and dichloromethane.

[0015] In the above preparation method, preferably, in step (2), the second solvent comprises one or a combination of two or more of ethanol, isopropyl alcohol and acetonitrile.

[0016] In the above preparation method, preferably, in step (1), the perfluoroalkylsulfonyl fluoride is C n F 2n+1 SO2F, n=4 or 6, and the solvent is isopropyl ether.

[0017] According to a specific embodiment of the present application, the above preparation method can be carried out according to the following specific steps:

[0018] (1) Put 1-2 parts of 3-dimethylaminopropylamine or diethylamine into a three-necked flask according to the molar ratio, add solvent (diethyl ether, isopropyl ether, dichloromethane), drop 1 part of perfluoroalkylsulfonyl fluoride (C n F 2n+1 SO2F, n = 2-10) or perfluoroalkylcarbonyl fluoride (C n F 2n+1 COF, n = 2-10) under ice water bath, adjust the temperature to 30-60℃ after completion, and remove the solvent after 2-4 hours of reaction. The fluorine-containing intermediate is generated.

[0019] (2) Put 1 part of the fluorine-containing intermediate into a three-necked flask, dissolve completely in acetonitrile at 60-90℃, add 1-2 parts of 3-chloro-2-hydroxypropane sulfonic acid sodium salt, sodium chloroacetate or 2-chloroethyl sulfonic acid sodium, adjust the pH to alkaline condition with sodium hydroxide, and react for 5-12 hours to obtain the fluorine-containing amphoteric ion type oil washing agent.

[0020] The novel oil-based drilling cuttings oil washing agent of the present application has the following excellent effects compared with the commonly used industrial oil washing agent:

[0021] (1) Good oil washing effect: the oil washing effect of different oil washing agents is compared and evaluated by Soxhlet extraction-mass method, the newly synthesized fluorine-containing amphoteric ion oil washing agent can quickly strip the oil from the surface of the drilling cuttings compared with the commonly used industrial oil washing agent, and can effectively avoid oil-water emulsification.

[0022] (2) Small dosage: compared with the existing commonly used industrial cleaning agent, the dosage is reduced by more than 30%;

[0023] (3) Strong applicability: it can clean most of the oil-containing solid waste returned from oil wells, especially has good adaptability to oil-containing drilling cuttings with high dispersity and small particle size. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The infrared spectrum of CFC-4 amphoteric ion and other characteristic functional groups in Example 1. DETAILED DESCRIPTION

[0025] In order to have a clearer understanding of the technical features, objectives and beneficial effects of the present application, the technical solutions of the present application are described in detail as follows, but it cannot be understood as limiting the scope of the present application.

[0026] Example 1:

[0027] The present embodiment provides a fluorine-containing amphoteric ion type oil washing agent, which is prepared by the following steps: taking 0.12 mol of 3-dimethylaminopropylamine and 150 mL of isopropyl ether into a three-necked flask, drop 0.1 mol of perfluoroalkylsulfonyl fluoride (C n F 2n+1SO2F, n = 4), after the drop is finished, the reaction is carried out for 3 hours, and the fluorine-containing intermediate is obtained.

[0028] The 0.1 mol fluorine-containing intermediate and 150 mL acetonitrile are added into a three-neck flask, the reaction temperature is adjusted to 60-90°C, 1-2 mol sodium salt of chloroacetic acid is added, and the reaction system is kept under alkaline condition for 5-12 hours. The fluorine-containing zwitterion (betaine type) oil-washing agent CFC-4 is obtained, and the infrared spectrum of the zwitterion characteristic is shown in Figure 1 The critical micelle concentration and surface tension of the oil-washing agent CFC-4 are shown in Table 1, and the wettability of the drilling cuttings is shown in Table 2. The results show that the oil-washing agent CFC-4 has hydrophobic and oleophobic properties, and has a wettability modification effect on the surface of the drilling cuttings.

[0029] Table 1 CMC and γ of the oil-washing agent CMC

[0030] Fluorine-containing amphoteric ion oil washing agent CMC (mol / L) CMC (mN / m)]]> ​ CFC-4 4.53 x 10 -4 ]] 18.3 CFS-4 1.56 x 10 -4 ]]> 16.4 CFS-6 3.30 x 10 -5 ]]> 12.2

[0031] Table 2 Influence of the oil-washing agent on the wettability of the drilling cuttings

[0032]

[0033] Example 2:

[0034] The fluorine-containing zwitterion type oil-washing agent is prepared by the following steps: 0.12 mol 3-dimethylamino propylamine is added into 150 mL isopropyl ether in a three-neck flask, 0.1 mol perfluoroalkylsulfonyl fluoride (C n F 2n+1 SO2F, n = 4) is added dropwise under ice water bath, and the reaction is carried out for 3 hours after the drop is finished. The fluorine-containing intermediate is obtained.

[0035] The 0.1 mol fluorine-containing intermediate and 150 mL acetonitrile are added into a three-neck flask, the reaction temperature is adjusted to 60-90°C, 1-2 mol 3-chloro-2-hydroxy propane sulfonic acid sodium salt is added, and the reaction system is kept under alkaline condition for 5-12 hours. The fluorine-containing zwitterion (sulfobetaine type) oil-washing agent CFS-4 is obtained, and the critical micelle concentration and surface tension are shown in Table 1. The wettability of the drilling cuttings is shown in Table 2. The results show that the oil-washing agent CFS-4 has hydrophobic and oleophobic properties, and has a wettability modification effect on the surface of the drilling cuttings.

[0036] Example 3:

[0037] The fluorine-containing zwitterion type oil-washing agent is prepared by the following steps: 0.12 mol 3-dimethylamino propylamine is added into 150 mL isopropyl ether in a three-neck flask, 0.1 mol perfluoroalkylsulfonyl fluoride (C nF 2n+1 SO2F, n = 6), after the dropwise addition was completed, the reaction was allowed to proceed for 3 hours, and then the reaction was completed.

[0038] Take 0.1 mol of the fluorine-containing intermediate and 150 mL of ethanol into a three-necked flask, adjust the reaction temperature to 60-90°C, add 1-2 mol of 3-chloro-2-hydroxypropane sulfonic acid sodium salt, and keep the reaction system under alkaline conditions for 5-12 hours. The fluorine-containing zwitterionic oil washing agent CFS-6 is obtained, the critical micelle concentration and surface tension of which are shown in Table 1, and the wettability of the drilling cuttings is shown in Table 2. The results show that the oil washing agent CFS-6 has strong hydrophobic and oleophobic properties, and can modify the surface of the drilling cuttings, and increase the water phase contact angle of the drilling cuttings to 118° and the oil phase contact angle to 112°.

[0039] Performance test of the new oil-based drilling cuttings oil washing agent

[0040] The oil washing effects of the fluorine-containing zwitterionic oil washing agents CFC-4, CFS-4 and CFS-6 prepared in Examples 1, 2 and 3 are evaluated, and compared with two commonly used industrial oil washing agents (sodium dodecyl benzene sulfonate and glycerol monostearate). The specific experimental operation is as follows:

[0041] Take some oil-containing drilling cuttings (oil content 10.3%) for oil washing effect evaluation; the three fluorine-containing zwitterionic oil washing agents obtained in Examples 1-3 and the two industrial oil washing agents are all prepared into aqueous solutions at a dosage of 3%, and the mass ratio (solid-liquid ratio) of the oil-containing drilling cuttings to the 3% oil washing agent solution is 1:3, 1:5 and 1:7. The oil content of the oil-containing drilling cuttings before and after cleaning is determined by Soxhlet extraction-differential method, and the oil removal rate of the oil-containing drilling cuttings is calculated according to the following formula (1):

[0042] w0 = (m0-m1) / m0x100% formula (1)

[0043] In formula (1), w0 is the oil removal rate; m0 is the oil mass (g) in the drilling cuttings before cleaning; and m1 is the oil mass (g) in the drilling cuttings after cleaning.

[0044] During the cleaning process, the emulsification of oil and water is observed. The relevant experimental results are shown in Table 3 as follows:

[0045] Table 3 Comparison of oil removal performance of oil-based drilling cuttings oil washing agents

[0046]

[0047] According to the experimental results in Table 3, it can be seen that: (1) the solid-liquid ratio, i.e. the mass ratio of oil-containing drilling cuttings to oil washing agent solution, affects the oil removal rate of all oil washing agents. The lower the solid-liquid ratio, the higher the oil removal rate and the better the cleaning effect; (2) under the same solid-liquid ratio, for example, the solid-liquid ratio of 1:7, the oil removal rate of the fluorine-containing amphoteric ion oil washing agent CFC-4 is the highest and the cleaning effect is the best, and the order of the oil removal rate is: CFC-4>glyceryl monostearate>CFS-4>CFS-6>sodium dodecyl benzene sulfonate; (3) from the oil-water emulsification phenomenon in the cleaning process, the fluorine-containing amphoteric ion oil washing agents (CFC-4, CFS-4, CFS-6) have high oil removal rate and do not produce oil-water emulsification phenomenon, which does not affect the subsequent oil-water separation, and are obviously superior to the two industrial oil washing agents.

Claims

1. A method for preparing a fluoro-amphiphilic oil agent, comprising the steps of: (1) mixing 3-dimethylamino propylamine or diethylamine with a first solvent, adding dropwise perfluoroalkylsulfonyl fluoride or perfluoroalkyl acyl fluoride under ice water bath, reacting at 30-60 °C for 2-4 hours, removing the solvent to form a fluoro-intermediate; (2) mixing the fluoro-intermediate with a second solvent at 60-90 °C, adding sodium salt of chloroacetic acid, adjusting pH to react under alkaline condition for 5-12 hours to obtain the fluoro-amphiphilic oil agent.

2. The production method according to claim 1, wherein, The pH of the alkaline condition is 8-9.

3. The production method according to claim 1, wherein, The perfluoroalkylsulfonyl fluoride is C n F 2n+1 SO2F, n = 2-10.

4. The production method according to claim 1, wherein The perfluoroalkyl acyl fluoride is C m F 2m+1 COF, m = 2-10.

5. The production method according to claim 1, wherein In step (1), the molar ratio of the perfluoroalkylsulfonyl fluoride or perfluoroalkyl acyl fluoride, 3-dimethylamino propylamine or diethylamine is 1:1-3.

6. The production method according to claim 1, wherein The molar ratio of the perfluoroalkylsulfonyl fluoride or perfluoroalkyl acyl fluoride, 3-dimethylamino propylamine or diethylamine is 1:

2.

7. The production method according to claim 1, wherein In step (2), the molar ratio of the fluoro-intermediate and the sodium salt of chloroacetic acid is 1:1-2.

8. The production method according to claim 1, wherein The step (1) comprises mixing 3-dimethylamino propylamine with a first solvent, adding dropwise perfluoroalkylsulfonyl fluoride under ice water bath, reacting at 30-60 °C for 2-4 hours, removing the solvent to form a fluoro-intermediate.

9. The production method according to claim 1, wherein In step (1), the first solvent comprises one or more than two combinations of diethyl ether, isopropyl ether, dichloromethane.

10. The production method according to claim 1, wherein In step (2), the second solvent comprises one or more than two combinations of ethanol, isopropyl alcohol, acetonitrile.

11. The production method according to claim 1, wherein In step (1), the perfluoroalkylsulfonyl fluoride is C n F 2n+ 1SO2F, n = 4 or 6, and the solvent is isopropyl ether.

12. A fluoro-amphiphilic oil agent prepared by the method of any one of claims 1-11.

13. A method for oiling, using the fluoro-amphiphilic oil agent of claim 12.

Images