Sulfonated asphalt for drilling fluid and preparation method thereof

Abstract

The invention discloses sulfonated asphalt for drilling fluid and a preparation method thereof. The preparation method comprises the following steps: (1) crushing asphalt, dissolving the crushed asphalt in an organic solvent, adding a sulfoxide catalyst and halogenated imide, and uniformly stirring to obtain a mixed material; (2) adding sulfite and / or hydrosulfite into the mixed material obtained in the step (1), and reacting; and (3) after the reaction in the step (2) is finished, cooling, separating, recovering an oil phase, concentrating a water phase, drying and crushing to obtain the sulfonated asphalt for the drilling fluid. The sulfonated asphalt for the drilling fluid has the characteristics of mild and controllable reaction conditions, quick and sufficient reaction, few side reactions, cheap and easily available reaction raw materials and the like during preparation, and the sulfonated product prepared by the method has good thermal stability and remarkable filtration loss reduction effect under high-temperature conditions.

Description

Technical Field

[0001] The invention belongs to the technical field of asphalt, and particularly relates to a method for preparing sulfonated asphalt for drilling fluid. Background Art

[0002] With the development of high-difficulty drilling technologies such as deep wells, directional wells and horizontal wells, the performance requirements of drilling fluid additives have gradually increased. Sulfonated asphalt, as a multifunctional drilling fluid additive with good performance and low cost, has multiple properties such as reducing the high-temperature and high-pressure filtration loss of drilling fluid, increasing the lubricity of mud cake, and improving the high-temperature stability of drilling fluid. It plays an important role in protecting geological reservoirs and is particularly suitable for the drilling of deep wells and ultra-deep wells.

[0003] Sulfonated asphalt currently used is a product obtained by sulfonation, neutralization and post-treatment of asphalt and a sulfonating agent (concentrated sulfuric acid or sulfur trioxide) under certain conditions. For example, US3489842 uses petroleum asphalt as raw material and sulfur trioxide as sulfonating agent, performs sulfonation, and neutralizes with sodium hydroxide to prepare sulfonated asphalt, which is used as a fluid loss reducer for oil drilling. US3970690 uses petroleum asphalt as raw material and sulfur trioxide as sulfonating agent, treats at 80°C for 3 hours, neutralizes with calcium hydroxide, filters, neutralizes and concentrates the filtrate with sodium hydroxide, and dries to prepare sulfonated asphalt powder. CN1037916A discloses a preparation process for a sulfonated asphalt drilling mud treating agent, which uses gaseous sulfur trioxide as a sulfonating agent and light oil as a solvent, performs a sulfonation reaction at a reaction temperature of 20 to 40°C to prepare sulfonated asphalt. The method obtains gaseous SO3 by evaporating fuming sulfuric acid, which solves the problem of storage and transportation of liquid sulfur trioxide, but the production process is complicated and an additional acid distillation kettle needs to be configured. CN1239133A discloses a sulfonated asphalt for high-temperature and high-pressure drilling fluid and a preparation method thereof, wherein a mixture of coal tar and petroleum asphalt is used as raw materials, dissolved in liquid alkanes such as octane, nonane, decane or 1,2-dichloroethane non-polar halogenated alkane solvent, and sulfur trioxide is used as a sulfonating agent, and a brown-black sulfonated asphalt product is obtained through sulfonation, neutralization, and drying. When sulfur trioxide is used as a sulfonating agent in the production of sulfonated asphalt, it has the characteristics of strong sulfonation ability, fast reaction, high conversion rate, low raw material unit consumption, and low cost; however, since sulfur trioxide has strong oxidizing properties and strong reaction activity, the reaction is difficult to control, and it is easy to produce side reactions such as multiple sulfonation, coking, and oxidation, and there are problems such as high equipment requirements, difficulty in storing and transporting sulfur trioxide, and high danger in the production process. CN106318344A discloses a sulfonated asphalt for drilling fluid and a preparation method thereof, wherein the method uses concentrated sulfuric acid and phosphorus pentoxide as sulfonating agents, utilizes SO3 generated by the in-situ reaction of concentrated sulfuric acid and phosphorus pentoxide to perform temperature-controlled sulfonation on asphalt, and obtains sulfonated asphalt through a potassium hydroxide solution neutralization step. The reaction conditions of concentrated sulfuric acid and phosphorus pentoxide are harsh, the obtained SO3 is less, and the sulfonation efficiency is low. CN103805219A discloses a preparation process for sulfonated asphalt, wherein the process uses an asphalt dissolving tank to dissolve solid asphalt and then adds it to kerosene, waits for the asphalt to be completely dissolved, adds sulfuric acid to carry out sulfonation reaction, waits for the sulfonation reaction to be completed, recycles kerosene, neutralizes and dries to obtain sulfonated asphalt. When sulfonated asphalt is sulfonated with concentrated sulfuric acid and oleum, the reaction activity of the sulfonating agent is low, the sulfonation effect is poor, the acid consumption is large, the equipment is severely corroded, the waste acid is seriously polluted, the sulfonation efficiency is not high, and the product quality is unstable. In the subsequent neutralization reaction, due to the presence of a large amount of unreacted sulfuric acid, a large amount of Na2SO4 inorganic salt is introduced into the product, resulting in severe foaming and poor stability of the product, which affects the product performance of the sulfonated asphalt.

[0004] In summary, the above sulfonated asphalt production technologies all have defects to varying degrees, and it is urgent to develop a new sulfonated asphalt preparation method suitable for drilling fluid. Summary of the invention

[0005] In view of the shortcomings and defects of the prior art, the present invention provides a sulfonated asphalt for drilling fluid and a preparation method thereof. The sulfonated asphalt for drilling fluid of the present invention has the characteristics of mild and controllable reaction conditions, rapid and sufficient reaction, few side reactions, and cheap and readily available reaction raw materials when prepared. The sulfonated product prepared by the present invention has good thermal stability and a significant effect of reducing filtration loss under high temperature conditions.

[0006] The present invention provides a method for preparing sulfonated asphalt for drilling fluid, comprising the following steps:

[0007] (1) crushing asphalt, dissolving it in an organic solvent, adding a sulfoxide catalyst and a halogenated imide, and stirring to obtain a mixed material;

[0008] (2) adding sulfite and / or bisulfite to the mixed material obtained in step (1) to carry out a reaction;

[0009] (3) After the reaction in step (2) is completed, the reaction is cooled, separated, the oil phase is recovered, and the water phase is concentrated, dried, and crushed to obtain sulfonated asphalt for drilling fluid.

[0010] In step (1), the asphalt is selected from at least one of natural asphalt, petroleum asphalt and oxidized asphalt. The asphalt has a saturated content of less than 15wt%, preferably 5wt%-12wt%, and an asphaltene content of more than 7wt%, preferably 11wt%-40wt%.

[0011] In step (1), the asphalt is crushed to a particle size of 60 mesh or more, preferably 80-90 mesh.

[0012] In step (1), the organic solvent is selected from at least one of dichloromethane, 1,2-dichloroethane, n-hexane, cyclohexane, heptane, octane, decane, gasoline, diesel, carbon tetrachloride, and kerosene, preferably at least one of n-hexane, carbon tetrachloride, and diesel.

[0013] In step (1), the amount of the organic solvent used can be sufficient to fully dissolve the asphalt. Generally, the concentration of the asphalt in the organic solvent is 0.05-5.0 g / mL.

[0014] In step (1), the sulfoxide catalyst is at least one selected from dimethyl sulfoxide, phenethyl sulfoxide, diethyl sulfoxide, diphenyl sulfoxide, and methyl ethyl sulfoxide, preferably at least one selected from dimethyl sulfoxide and diethyl sulfoxide.

[0015] In step (1), the halogenated imide reagent is selected from at least one of N-chlorosuccinimide (NCS), N-bromosuccinimide (NBS), and N-iodosuccinimide (NIS); preferably at least one of N-chlorosuccinimide (NCS) and N-bromosuccinimide (NBS).

[0016] In step (1), the weight ratio of the asphalt to the halogenated imide is 1-15:1, preferably 4-9:1.

[0017] In step (1), the weight ratio of the halogenated imide to the sulfoxide catalyst is 1-10:1, preferably 2-5:1.

[0018] The temperature of the mixture obtained in step (1) is controlled to 10-100° C., preferably 20-40° C.

[0019] The reaction temperature of step (2) is 10-100°C, preferably 20-40°C, and the reaction time is 10 min-4 h, preferably 20 min-1 h.

[0020] In step (2), the sulfite is selected from at least one of sodium sulfite, potassium sulfite, calcium sulfite, and magnesium sulfite; preferably potassium sulfite; the bisulfite is selected from at least one of sodium bisulfite, potassium bisulfite, calcium bisulfite, and magnesium bisulfite; preferably potassium bisulfite.

[0021] In step (2), the weight ratio of the asphalt to the sulfite and / or bisulfite is 1-10:1, preferably 6-9:1.

[0022] In step (3), the cooling is cooling to 10-30°C, preferably cooling to room temperature.

[0023] In step (3), the drying conditions are: temperature of 110-140° C. and time of 1-5 h.

[0024] The second aspect of the present invention provides a sulfonated asphalt for drilling fluid prepared by the above method.

[0025] The sulfonated asphalt for drilling fluid has a volatile matter content of ≤10.0wt%, a water-soluble matter of ≥70.0wt%, an oil-soluble matter of ≥25.0wt%, a metal sulfonate group (such as potassium sulfonate group) content of ≥10.0wt%, preferably a metal sulfonate group content of ≥15.0wt%, and a high-temperature and high-pressure fluid loss reduction of 150°C (mL / 30min) ≤20mL, which is better than the value specified in Q / SHCG 3-2011 "Technical Requirements for Asphalt Treatment Agents for Drilling Fluids" (high-temperature and high-pressure fluid loss reduction of sulfonated asphalt at 150°C (mL / 30min) ≤25mL), wherein the high-temperature and high-pressure fluid loss reduction is measured at 150°C and 3.5MPa according to the method of GB / T 16783.1.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] (1) The halogenated imide in the present invention reacts with olefins in asphalt under the action of a sulfoxide catalyst to undergo an oxoamination reaction, embedding the imide anion into the asphalt molecule, converting the unsaturated carbon-carbon bond into a carbon-oxygen bond with higher stability while complying with atom economy, and replacing the halogen atom with sulfite and / or bisulfite to generate sulfonate, thereby achieving effective control of the sulfonation reaction rate, solving the problem of the existing SO3 sulfonation method that is difficult to control the reaction, making the molecule have better high-temperature stability, and the high-temperature filtration loss reduction effect is more significant.

[0028] (2) The introduction of metal ions such as potassium ions in sulfites and bisulfites can improve the anti-collapse ability of sulfonated asphalt. The sulfonated asphalt product of the present invention has a potassium sulfonate content of ≥15wt%, and a high temperature and high pressure filtration loss reduction of 150°C (mL / 30min) ≤20mL, both of which are better than the values ​​specified in Q / SHCG 3-2011 "Technical Requirements for Asphalt Treatment Agents for Drilling Fluids".

[0029] (3) The present invention does not require special SO3 storage and transportation equipment, and does not require additional acid distillation tanks and other equipment, which can greatly reduce the production equipment requirements and hazards of sulfonated asphalt and is suitable for large-scale production.

[0030] (4) The present invention has the characteristics of sufficiently rapid sulfonation reaction, easy reaction control, stable product quality, and large-scale production. It can be widely used in the sulfonation production of natural asphalt, petroleum asphalt, coal asphalt and other asphalts. DETAILED DESCRIPTION

[0031] The present invention will be further described below in conjunction with the embodiments.

[0032] According to SY / T 5794-2010 "Evaluation Methods for Asphalt in Drilling Fluids" and Q / SHCG 3-2011 "Technical Requirements for Asphalt Treatment Agents for Drilling Fluids", the specific evaluation method for this product is as follows:

[0033] 1. Determination of volatile matter content

[0034] (1) Weigh 3g-5g of the sample (mass is m1, accurate to 0.0001g) and place it in a weighing bottle with a constant mass.

[0035] (2) Dry the sample in an oven at 105±3℃ for 2 h, take it out and place it in a desiccator. After cooling to room temperature, weigh its mass (mass is m2, accurate to 0.0001 g).

[0036] (3) Calculate the moisture content of the sample according to the formula:

[0037] W1=(m1-m2) / m1×100%

[0038] Where: W1-volatile matter content, expressed as percentage (%);

[0039] m1-mass of the sample before drying, in grams (g);

[0040] m2-mass of the sample after drying, in grams (g).

[0041] 2. Content of metal sulfonic acid group (taking potassium sulfonate group as an example)

[0042] 2.1 Determination of free sulfate

[0043] (1) Weigh 0.5 g of sample (mass is m3, accurate to 0.0001 g), place it in a 200 mL beaker, add 50 mL of distilled water, and heat to boil for 10 min.

[0044] (2) After adjusting the pH to ≤ 1 with 15 wt % hydrochloric acid solution, add 3.5-4.0 g of activated carbon, stir for 5 min, boil for 3 min, filter with qualitative medium-speed filter paper into a 250 mL beaker while hot, and finally wash with 1 wt % hydrochloric acid until there is no sulfate (check with 1 wt % barium chloride solution).

[0045] (3) When the filtrate is heated and concentrated to about 100 mL, the pH is adjusted to 4-5 with a 5 wt % sodium hydroxide solution, and then 5 mL of a 10 wt % barium chloride solution is added dropwise to precipitate sulfate at 60-80° C. for 1 hour.

[0046] (4) The precipitate is filtered with a quantitative slow filter paper and washed with distilled water at about 80°C until there is no chloride ion (check with 1wt% silver nitrate solution). The precipitate and filter paper are placed in a crucible with a constant mass, incinerated on an electric furnace, moved into a high-temperature furnace, and burned at 800-900°C for 1 hour. The precipitate is taken out and placed in a desiccator, cooled to room temperature, and then weighed (mass is m4, accurate to 0.0001g).

[0047] 2.2 Determination of total sulfur content

[0048] (1) Weigh 0.5 g of sample (mass is m5, accurate to 0.0001 g), put it into a 30 mL crucible, add about 5-10 mL of distilled water to dissolve the sample, then add 5 mL of 10 wt% barium chloride aqueous solution, slowly heat to boiling while stirring. When it is almost dry, add 10 mL of barium hydroxide colloidal solution, evaporate until it is almost dry, transfer to a high temperature furnace, and burn at 800-900 ° C for 1 hour.

[0049] (2) Dissolve the above-mentioned burning residue with 10 mL of 15 wt% hydrochloric acid solution until the precipitate is free of black and gray (otherwise it should be redone), transfer it into a 100 mL beaker, boil and filter, and wash with distilled water until there is no chloride ion (check with 1 wt% silver nitrate solution).

[0050] (3) Place the precipitate and filter paper in a constant weight crucible, incinerate in an electric furnace, move into a high temperature furnace, burn at 800-900°C for 1 hour, take out and place in a desiccator, cool to room temperature and weigh (mass is m6, accurate to 0.0001g)

[0051] 2.3 Calculation of potassium sulfonate content

[0052] W2=(m6 / m5-m4 / m3)×0.5103×100%

[0053] Where:

[0054] W2-potassium sulfonate content, expressed as a percentage (%);

[0055] m3-the mass of the sample when determining free sulfate, in grams (g);

[0056] m4-the mass of barium sulfate when determining free sulfate, in grams (g);

[0057] m5-the mass of the sample when measuring total sulfur, in grams (g);

[0058] m6-the mass of barium sulfate when total sulfur is measured, in grams (g);

[0059] 0.5103-The ratio of potassium sulfonate to barium sulfate, dimension is 1.

[0060] 3. Determination of water-soluble matter content

[0061] (1) Take 0.2-0.3 g of absorbent cotton and put it into a roll made of lens paper. Dry it at 105±3℃ to constant weight and set aside.

[0062] (2) Fold the lens cleaning paper that has been weighed to a constant weight in half and lay it flat on a clean weighing paper. Then lay the absorbent cotton evenly in the middle of the lens cleaning paper. Weigh 0.5g of the sample (mass is m9, accurate to 0.0001g) that has been ground and passed through a standard sieve with a side length of 0.28mm, and pour it on the center of the absorbent cotton.

[0063] (3) First wrap the sample tightly with absorbent cotton, then wrap the cotton tightly with lens cleaning paper, and finally wrap the sample with thread (mass m 10 , accurate to 0.1 mg).

[0064] Note: No sample should leak out during the packing process, and the sample should not be clearly visible in the packed sample package. Put the sample package into the sample cup in the extractor, and hang the sample cup under the micro condenser in the extractor.

[0065] (4) Pour 250mL-300mL of water into the extractor. Place the extractor in an electric heating jacket and heat it until the effluent is colorless. Take out the sample cup, place the paper roll in a drying oven, dry it at 105±3℃ for 2h, take it out and place it in a desiccator, cool it for 30min, and weigh it (mass is m 11 , accurate to 0.1 mg).

[0066] (5) Calculate the water solubility according to the formula:

[0067] W4=(m 10 -m 11 ) / m9×100%

[0068] Where: W4-water solubility, %;

[0069] m9-sample mass, g;

[0070] m 10 -Mass of absorbent cotton, lens cleaning paper and sample, g;

[0071] m 11 -Mass of absorbent cotton, lens cleaning paper and residue, g.

[0072] 4. Determination of oil-soluble matter content

[0073] (1) Place 0.2-0.3 g of cotton wool, a piece of lens cleaning paper, and a piece of suitable thread in a weighing bottle, dry at 105±3℃ to constant weight, and set aside.

[0074] (2) Fold the lens cleaning paper that has been weighed to a constant weight in half and lay it flat on a clean weighing paper. Then lay the absorbent cotton evenly in the middle of the lens cleaning paper. Weigh 0.5 g (mass m) of the sample that has been ground and passed through a standard sieve with a side length of 0.28 mm. 12 , accurate to 0.1 mg), pour it onto the center of the cotton wool.

[0075] (3) First wrap the sample tightly with absorbent cotton, then wrap the cotton tightly with lens cleaning paper, and finally wrap the sample with thread (mass m 13 , accurate to 0.1 mg).

[0076] Note: No sample should leak out during the packing process, and the sample should not be clearly visible in the packed sample package. Put the sample package into the sample cup in the extractor, and hang the sample cup under the micro condenser in the extractor.

[0077] (4) Inject 250mL-300mL of carbon tetrachloride into the extractor. Place the extractor in an electric heating mantle and heat it and keep it boiling until the effluent is colorless. Take out the sample cup, place the paper roll in a drying oven, dry it at 105±3℃ for 2h, take it out and place it in a dryer, cool it for 30min, and then weigh it (mass is m 14 , accurate to 0.1 mg).

[0078] (5) Calculate the oil solubility rate according to the formula:

[0079] W5=(m 13 -m 14 ) / m 12 ×100%

[0080] In the formula: W5-oil solubility rate, %;

[0081] m 12 - Sample mass, g;

[0082] m 13 -Mass of absorbent cotton, lens cleaning paper and sample, g;

[0083] m 14 -Mass of absorbent cotton, lens cleaning paper and residue, g.

[0084] 5. Determination of high temperature and high pressure filtration loss reduction rate

[0085] (1) Preparation of drilling fluid base slurry: Take 350 mL of distilled water, slowly add 14.0 g of sodium bentonite for drilling fluid test under stirring, stir at high speed for 20 min, pour into a curing tank and let stand for 24 h, then add 7.0 g of iron chromium lignin sulfonate and 7.0 g of evaluation soil, stir at low speed for 30 min, adjust the pH value to 10 with 20 wt% sodium hydroxide, and stir at high speed for 20 min to obtain the base slurry.

[0086] (2) Add 7.0 g of the sample to be tested to the base slurry and stir at low speed for 30 min. Adjust the pH value to 10 with 20 wt % sodium hydroxide and stir at high speed for 20 min. Stop stirring at least twice during stirring to scrape off the mud, soil powder or sample adhering to the wall of the cup. Stir at low speed (not exceeding 4000 r / min, appropriately controlled according to the viscosity of the slurry) for 1 h and measure the HTHP (150 °C, 3.5 MPa) filtration loss according to GB / T 16783.1.

[0087] The following non-limiting examples can enable those skilled in the art to more fully understand the present invention, but do not limit the present invention in any way. In addition, the percentages involved in the present invention, unless otherwise specified, are all mass percentages.

[0088] Example 1

[0089] 280 mL of n-hexane was added to a 500 mL three-necked flask, and 70 g of a 80-mesh natural asphalt and petroleum asphalt mixture (asphaltenes content was 7 wt%, saturated content was 15 wt%, and natural asphalt accounted for 10 wt% of the mixture) was added under constant stirring. After being fully dissolved, 4.7 g of N-chlorosuccinimide (NCS) and 0.5 g of dimethyl sulfoxide were added and stirred evenly. The obtained mixed solution was temperature-controlled to 20° C., and after the temperature was stabilized, 7.0 g of potassium sulfite was added to react for 20 min, the oil layer was separated, the oil layer was recovered, and the aqueous phase concentrate was placed in a dryer, dried at 110° C. for 1 h, and then crushed to obtain a brown-black sulfonated asphalt powder. The prepared sulfonated asphalt had a volatile content of 9.3 wt%, a water-soluble content of 71.2 wt%, an oil-soluble content of 25.1 wt%, a potassium sulfonate content of 15.5 wt%, and a high-temperature and high-pressure filtration loss of 19 mL (150° C. (mL / 30 min).

[0090] Example 2

[0091] Add 550mL of carbon tetrachloride to a 1000mL three-necked flask, add 120g of 80-mesh petroleum asphalt (asphalt content is 26wt%, saturated content is 9wt%) under constant stirring, and after it is fully dissolved, add 30.0g of a mixture of N-chlorosuccinimide (NCS) and N-iodosuccinimide (NIS) (NCS to NIS mass ratio = 5:3) and 15.0g of dimethyl sulfoxide, and stir evenly; control the temperature of the obtained mixed solution to 35°C, add 20.0g of potassium bisulfite after the temperature stabilizes, react for 50min after addition, separate the oil layer, recover the oil layer, place the aqueous phase concentrate in a dryer, dry it at 120°C for 4h, and then crush it to obtain a brown-black sulfonated asphalt powder. The prepared sulfonated asphalt has a volatile content of 7.8wt%, a water-soluble content of 73.2wt%, an oil-soluble content of 25.6wt%, a potassium sulfonate content of 18.1wt%, and a high-temperature and high-pressure filtration loss of 14mL (150℃ (mL / 30min).

[0092] Example 3

[0093] Add 160 mL of diesel to a 250 mL three-necked flask, add 50 g of 90-mesh oxidized asphalt (asphaltene content is 11 wt%, saturated content is 12 wt%) under constant stirring, and after it is fully dissolved, add 50.0 g of N-iodosuccinimide (NIS) and 50.0 g of diethyl sulfoxide, and stir evenly; control the temperature of the obtained mixed solution to 30°C, and after the temperature stabilizes, add 50.0 g of a mixture of potassium sulfite and potassium bisulfite (mass ratio of potassium sulfite to potassium bisulfite = 1:1), react for 1 hour after the addition is completed, separate the oil layer, recover the oil layer, place the aqueous phase concentrate in a dryer, dry it at 130°C for 5 hours, and then crush it to obtain a brown-black sulfonated asphalt powder. The prepared sulfonated asphalt has a volatile content of 9.0wt%, a water-soluble content of 71.9wt%, an oil-soluble content of 25.1wt%, a potassium sulfonate content of 16.2wt%, and a high-temperature and high-pressure filtration loss of 18mL (150℃ (mL / 30min).

[0094] Example 4

[0095] 300 mL of carbon tetrachloride was added to a 500 mL three-necked flask, and 100 g of a mixture of 80-mesh petroleum asphalt and oxidized asphalt (asphaltenes content was 40 wt%, saturated content was 5 wt%, and oxidized asphalt accounted for 20 wt% of the mixture) was added under constant stirring. After being fully dissolved, 11.1 g of a mixture of N-chlorosuccinimide (NCS) and N-bromosuccinimide (NBS) (NCS to NBS mass ratio = 3:2) and 2.2 g of dimethyl sulfoxide were added and stirred evenly. The obtained mixed solution was temperature-controlled to 40°C, and after the temperature stabilized, 11.1 g of a mixture of potassium sulfite and potassium bisulfite (potassium sulfite to potassium bisulfite mass ratio = 6:5) was added. After the addition was completed, the mixture was reacted for 30 min, the oil layer was separated, the oil layer was recovered, and the aqueous phase concentrate was placed in a dryer, dried at 135°C for 2 h, and then crushed to obtain a brown-black sulfonated asphalt powder. The prepared sulfonated asphalt has a volatile content of 8.5wt%, a water-soluble content of 72.6wt%, an oil-soluble content of 25.4wt%, a potassium sulfonate content of 17.6wt%, and a high-temperature and high-pressure filtration loss of 15mL (150℃ (mL / 30min).

[0096] Example 5

[0097] Add 600 mL of n-hexane to a 1000 mL three-necked flask, add 150 g of 90-mesh petroleum asphalt (asphaltene content is 25 wt%, saturated content is 8 wt%) under constant stirring, and after it is fully dissolved, add 21.4 g of N-bromosuccinimide (NBS) and 5.4 g of diethyl sulfoxide, and stir evenly; control the temperature of the obtained mixed solution to 30°C, and after the temperature stabilizes, add 18.7 g of a mixture of potassium sulfite and potassium bisulfite (mass ratio of potassium sulfite to potassium bisulfite = 1:4), react for 40 minutes after the addition is completed, separate the oil layer, recover the oil layer, place the aqueous phase concentrate in a dryer, dry it at 125°C for 3 hours, and then crush it to obtain a brown-black sulfonated asphalt powder. The prepared sulfonated asphalt has a volatile content of 7.0wt%, a water-soluble content of 73.9wt%, an oil-soluble content of 25.8wt%, a potassium sulfonate content of 19.0wt%, and a high-temperature and high-pressure filtration loss of 12mL (150℃ (mL / 30min).

[0098] Comparative Example 1

[0099] Add 600mL of n-hexane to a 1000mL three-necked flask, add 150g of 90-mesh petroleum asphalt (asphaltenes content is 25wt%, saturated content is 8wt%) under constant stirring, add 21.4g of N-bromosuccinimide (NBS) after it is fully dissolved, and stir evenly; control the temperature of the obtained mixed solution to 30°C, add 18.7g of a mixture of potassium sulfite and potassium bisulfite (mass ratio of potassium sulfite to potassium bisulfite = 1:4) after the temperature is stable, react for 40min after adding, separate the oil layer, recover the oil layer, place the concentrated aqueous phase in a dryer, dry it at 125°C for 3h, and then crush it to obtain a brown-black sulfonated asphalt powder. The prepared sulfonated asphalt has a volatile content of 9.5wt%, a water-soluble content of 70.2wt%, an oil-soluble content of 25.1wt%, a potassium sulfonate content of 11.2wt%, and a high temperature and high pressure filtration loss of 25mL (150°C (ml / 30min).

[0100] Comparative Example 2

[0101] 600mL of n-hexane was added to a 1000mL three-necked flask, and 150g of 90-mesh petroleum asphalt (asphaltenes content was 25wt%, saturated content was 8wt%) was added under constant stirring. After being fully dissolved, 10g of concentrated sulfuric acid (98wt%) was added dropwise to the reaction raw materials, and the sulfonation reaction temperature was controlled to be 30°C, and the reaction time was 40min. After the reaction was completed, sodium hydroxide solution (30wt%) was added until the pH value was 8, the oil layer was separated, the oil layer was recovered, and the aqueous phase concentrated liquid was placed in a dryer, dried at 125°C for 3h, and then crushed to obtain brown-black sulfonated asphalt powder. The prepared sulfonated asphalt had a volatile content of 9.2wt%, a water-soluble content of 70.0wt%, an oil-soluble content of 25.4wt%, a potassium sulfonate content of 12.0wt%, and a high-temperature and high-pressure filtration loss of 23mL (150°C (mL / 30min).

[0102] Comparing the above embodiments with similar products in the industry, it is found that the sulfonated asphalt disclosed in the present invention can meet the relevant technical requirements of the industry, and its high temperature and high pressure filtration loss reduction is 150℃ (mL / 30min)≤20.0mL, which greatly improves its plugging and anti-collapse effect. At the same time, the method of the present invention has the characteristics of mild, rapid and controllable reaction conditions, few side reactions, and cheap and easy-to-obtain catalysts and halogenating agents, and has the conditions for large-scale production.

Claims

1. A method for preparing sulfonated asphalt for drilling fluid, characterized in that: The following steps are involved: (1) crushing asphalt, dissolving it in an organic solvent, adding a sulfoxide catalyst and a halogenated imide, and stirring to obtain a mixed material; (2) adding sulfite and / or bisulfite to the mixed material obtained in step (1) to carry out a reaction; (3) After the reaction in step (2) is completed, the reaction is cooled, separated, the oil phase is recovered, and the water phase is concentrated, dried, and crushed to obtain sulfonated asphalt for drilling fluid.

2. The preparation method according to claim 1, characterized in that: In step (1), the asphalt is selected from at least one of natural asphalt, petroleum asphalt, and oxidized asphalt; the saturated content of the asphalt is less than 15wt%, preferably 5wt%-12wt%, and the asphaltene content is more than 7wt%, preferably 11wt%-40wt%.

3. The preparation method according to claim 1, characterized in that: In step (1), the asphalt is crushed to a particle size of 60 mesh or more, preferably 80-90 mesh.

4. The preparation method according to claim 1, characterized in that: In step (1), the organic solvent is selected from at least one of dichloromethane, 1,2-dichloroethane, n-hexane, cyclohexane, heptane, octane, decane, gasoline, diesel, carbon tetrachloride, and kerosene.

5. The preparation method according to claim 1, characterized in that: In step (1), the sulfoxide catalyst is at least one selected from dimethyl sulfoxide, phenethyl sulfoxide, diethyl sulfoxide, diphenyl sulfoxide, and methyl ethyl sulfoxide.

6. The preparation method according to claim 1, characterized in that: In step (1), the halogenated imide reagent is selected from at least one of N-chlorosuccinimide, N-bromosuccinimide and N-iodosuccinimide.

7. The preparation method according to claim 1, 2 or 6, characterized in that: The weight ratio of the asphalt to the halogenated imide is 1-15:1, preferably 4-9:

1.

8. The preparation method according to claim 1, 5 or 6, characterized in that: In step (1), the weight ratio of the halogenated imide to the sulfoxide catalyst is 1-10:1, preferably 2-5:

1.

9. The preparation method according to claim 1, characterized in that: The temperature of the mixture obtained in step (1) is controlled to 10-100° C., preferably 20-40° C.

10. The preparation method according to claim 1, characterized in that: The reaction temperature of step (2) is 10-100°C, preferably 20-40°C, and the reaction time is 10 min-4 h, preferably 20 min-1 h.

11. The preparation method according to claim 1, characterized in that: In step (2), the sulfite is selected from at least one of sodium sulfite, potassium sulfite, calcium sulfite, and magnesium sulfite, preferably potassium sulfite; the bisulfite is selected from at least one of sodium bisulfite, potassium bisulfite, calcium bisulfite, and magnesium bisulfite, preferably potassium bisulfite.

12. The preparation method according to claim 1, 2 or 11, characterized in that: In step (2), the weight ratio of the asphalt to the sulfite and / or bisulfite is 1-10:1, preferably 6-9:

1.

13. The preparation method according to claim 1, characterized in that: In step (3), the cooling is cooling to 10-30° C.; And / or, in step (3), the drying conditions are: temperature of 110-140° C. and time of 1-5 h.

14. A drilling fluid sulfonated asphalt prepared according to any one of claims 1 to 13.

15. The sulfonated asphalt according to claim 14, characterized in that: The sulfonated asphalt used in the drilling fluid has a volatile content of ≤10.0wt%, a water-soluble matter of ≥70.0wt%, an oil-soluble matter of ≥25.0wt%, a metal sulfonate content of ≥10.0wt%, preferably a metal sulfonate content of ≥15.0wt%, and a high-temperature and high-pressure filtration loss of 150°C (mL / 30min) ≤20mL.