Modified bitumen for water-based drilling fluids and method of making same

Abstract

The application discloses a modified asphalt for water-based drilling fluid and a preparation method thereof. The modified asphalt for water-based drilling fluid comprises the following raw material components: pretreated reducing slag, acid anhydride modifier, initiator, stabilizer, modifier, modification aid and performance regulator. The modifier is low-grade sulfur. The pretreated reducing slag comprises the following raw material components in weight: inferior reducing slag: 100 parts; oil sand asphalt: 20-60 parts; and pretreatment agent: 0.1-2 parts. The high-softening-point asphalt with high softening point and good hydrophilicity is obtained by modifying the difficult-to-handle inferior reducing slag and oil sand asphalt, and is suitable for being used as main material for producing asphalt water-based drilling fluid.

Description

Technical Field

[0001] This invention relates to the field of asphalt, and more specifically to a modified asphalt for water-based drilling fluid and its preparation method. Background Technology

[0002] Asphalt-based drilling fluids include oil-based and water-based drilling fluids, with oil-based fluids having certain drawbacks in terms of cost and environmental impact. Furthermore, since the main component of drilling fluid is mud, to ensure that the treatment agent is highly dispersed and adequately dissolved in the drilling fluid without agglomeration or floating, and to fully utilize the effect of the drilling fluid treatment agent, in addition to requiring the asphalt to have a high softening point, it is preferable to use a water-based drilling fluid treatment agent.

[0003] Significant progress has been made in the laboratory research and process technology of high-performance water-based drilling fluids, including their performance characteristics, wellbore stabilization mechanisms, composition and treatment agent effects, inhibition evaluation methods, and field application effects. They are now widely used in various complex drilling operations. Using high-performance drilling fluids not only significantly reduces drill bit mud packing and agglomeration, but also increases drilling speed, saves time and costs, and most importantly, improves wellbore stability in shale formations, greatly protecting the environment. Therefore, water-based drilling fluids are receiving increasing attention. While anhydride modification can improve the softening point and hydrophilicity of asphalt, asphalt is a relatively inert system with poor reactivity with anhydrides, resulting in a very low conversion rate. Unreacted anhydrides remain in the asphalt, corroding equipment; upon heating, small-molecule anhydrides volatilize, posing a health hazard and environmental risk. The low conversion rate also increases the amount of anhydride used, raising costs.

[0004] As crude oil becomes increasingly heavy, the yield of vacuum residue gradually increases, leading to higher levels of heavy metals and sulfur in the residue. The relative contents of saturated fractions and asphaltenes also rise, while the relative contents of aromatics and gums decrease. Furthermore, the asphaltenes exhibit greater association and more complex forms, making it more difficult to directly process high-grade asphalt from inferior residue. Therefore, for this increasingly deteriorating residue, modifying it to obtain intermediates with high softening points and good hydrophilicity for drilling fluid asphalt production is a better option.

[0005] CN1415699A discloses a method for producing oxidized asphalt. First, a static mixer is used to mix air and asphalt, dispersing the air as tiny bubbles into the asphalt raw material. Then, the mixture enters an oxidation unit for an oxidation reaction. This method can adjust the properties of asphalt when producing ordinary road asphalt and building asphalt, but it is not suitable for producing asphalt with a high softening point. This is because the amount of air present in asphalt at high temperatures is very small, resulting in limited oxidation efficiency and failing to significantly increase the softening point of the asphalt. Furthermore, coking occurs during the production process.

[0006] CN103805221B discloses a method for producing high softening point asphalt. The raw material for this method is a mixture of coal tar pitch and petroleum asphalt. The method utilizes the characteristics of low viscosity and high reactivity of coal tar pitch at high temperatures to promote the oxidation reaction. However, the oxidation process of coal tar pitch releases a large amount of toxic and harmful gases, which are harmful to the environment and human health. Furthermore, the high softening point asphalt prepared does not have hydrophilic properties and cannot be used as a raw material for preparing asphalt-based water-based drilling fluids.

[0007] In summary, the above methods have problems such as high energy consumption, complex processes, and environmental pollution when preparing high softening point asphalt. In addition, the ability to increase the softening point of asphalt during the preparation process is limited, and the high softening point asphalt produced has poor hydrophilicity, making it unsuitable as a raw material for preparing asphalt-based water-based drilling fluids. Summary of the Invention

[0008] To address the shortcomings of existing technologies, this invention provides a modified asphalt for water-based drilling fluids and its preparation method. This invention uses difficult-to-process, low-quality slag-reducing and oil sands asphalt as raw materials, and through modification treatment, obtains high-softening-point asphalt with good hydrophilicity, making it suitable as a main material for producing asphalt-based water-based drilling fluids.

[0009] The first aspect of this invention provides a modified bitumen for water-based drilling fluid, comprising the following raw material components by weight:

[0010] Pretreatment for slag reduction: 100 portions;

[0011] Anhydride modifier: 2-10 parts, preferably 3-9 parts;

[0012] Initiator: 0.08–0.8 parts, preferably 0.12–0.7 parts;

[0013] Stabilizer: 0.3 to 1.5 parts, preferably 0.5 to 1.5 parts;

[0014] Modifier: 3-15 parts, preferably 6-12 parts;

[0015] Modifying agent: 2-8 parts, preferably 2-4 parts;

[0016] Performance modifier: 0.5–12 parts, preferably 1.5–9 parts;

[0017] The modifier is low-grade sulfur;

[0018] The pretreatment slag reduction, by weight, includes the following raw material components:

[0019] Inferior slag reduction: 100 portions;

[0020] Oil sand asphalt: 20-60 parts, preferably 30-50 parts;

[0021] Pretreatment agent: 0.1 to 2 parts, preferably 0.2 to 1.2 parts.

[0022] The properties of the inferior slag include: a flash point of 241℃~256℃, a sulfur content of 2.61wt%~3.65wt%, and by mass fraction, saturated components of 26.1%~37.7%, aromatic components of 20.2%~34.5%, resins of 18.3%~24.8%, asphaltene of 21.3%~30.1%, with preferred asphaltene content of 21.3%~26.0%.

[0023] The inferior slag also has the following properties: residual carbon value of 21wt% to 29wt%, nitrogen content of 0.14wt% to 0.61wt%, total nickel and vanadium content of 320 to 365μg / g, and condensation index CI of 0.26 to 0.35.

[0024] The inferior reduced slag can be Tarim River reduced slag or other reduced slag that meets the above properties, and the inferior reduced slag is a fraction with an initial boiling point greater than 425°C.

[0025] The oil sands asphalt is one or more of the following: Inner Mongolia oil sands asphalt, Qinghai oil sands asphalt, Indonesian oil sands asphalt, and Kazakhstani oil sands asphalt.

[0026] The properties of the oil sands bitumen include: a softening point of not less than 50℃, preferably 55℃~65℃; a flash point of not less than 232℃, preferably 235℃~256℃; a pour point of 25℃~32℃; and a viscosity of 1450~1600 mmHg at 100℃. 2 .S -1 Preferably 1500-1600mm 2 .S -1 The residual carbon content is 9.5wt%–15.1wt%, the sulfur content is 2.0wt%–6.1wt%, the carbon content is 84wt%–87wt%, the hydrogen content is 10wt%–12.4wt%, and the nitrogen content is 0.2wt%–0.8wt%. By mass fraction, the saturated components account for 10.1%–30.7%, the aromatic components account for 15.6%–35.9%, the resin accounts for 30.4%–45.8%, the asphaltenes account for 10.7%–27.3%, and the preferred asphaltenes account for 11.3%–25.2%.

[0027] The pretreatment agent is a high-phosphoric acid polyphosphoric acid, wherein the phosphoric acid content, calculated as H3PO4, is 125% to 145% by mass, preferably 130% to 140%.

[0028] The anhydride modifier is one or more of maleic anhydride, polyisobutylene succinic anhydride, methyl nadic anhydride, modified methyl nadic anhydride MNA-10, dodecenyl succinic anhydride, tung oil anhydride, polyazelite anhydride, polyglutaric anhydride, polyoxoanhydride, or hydrolyzed polymaleic anhydride.

[0029] The initiator is one or more of dicumyl peroxide, tert-butyl hydroperoxide, benzoyl peroxide, sodium metabisulfite, azobisisobutyronitrile, azobisisoheptanenitrile, and cumyl hydroperoxide.

[0030] The stabilizer includes polyphosphoric acid with low phosphoric acid content, and also contains at least one of lauryl alcohol polyoxyethylene ether, hexadecyl alcohol polyoxyethylene ether, octadecyl alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether, octylphenol polyoxyethylene ether, dinonylphenol polyoxyethylene ether, and docosyl alcohol.

[0031] The content of the low-phosphoric acid polyphosphoric acid is 20% to 50%, preferably 25% to 45%, based on the mass of the stabilizer.

[0032] The low-phosphoric acid content polyphosphoric acid contains 105% to 115% phosphoric acid by mass, preferably 105% to 110%, calculated as H3PO4.

[0033] After drying, the low-grade sulfur has a sulfur content of 85wt%–90wt%, of which 90wt%–93wt% is in the form of rhombic sulfur. The remaining sulfur exists in water-soluble salts such as NH4SCN, (NH4)2S2O3, and FeSO4. The total amount of trace elements such as Fe, Br, Ca, P, Mo, and Cl is not less than 2.0wt%, and the total content of tar-like organic matter is not less than 1.5wt%.

[0034] The low-grade sulfur is preferably low-grade sulfur produced in the coal chemical industry after removing H2S using wet oxidation technology. This low-grade sulfur is then dried and dehydrated before being used as a modifier.

[0035] The low-grade sulfur can be sulfur foam, sulfur paste obtained by filtering or centrifuging sulfur foam, or sulfur obtained by melting sulfur foam.

[0036] In addition to sulfur, the low-grade sulfur also contains desulfurization byproducts such as NH4SCN, desulfurization catalysts, and tar-like organic matter.

[0037] The modified additive is a sulfur pretreatment agent.

[0038] The preparation process of the modified additive is as follows:

[0039] The dried elemental sulfur is added to a closed reactor, stirred and heated to produce sulfur vapor, and then heated to the reaction temperature to carry out the reaction. After the reaction is completed, the mixture is rapidly cooled and refined to obtain the final modified additive.

[0040] Further, the drying conditions are as follows: sulfur is dried at 55℃~65℃ for 2h~4h. The sealed reactor is preferably a high-pressure reactor, and before use, it is purged with nitrogen for 10~30min to ensure no air is present during the reaction. The heating temperature required for sulfur vapor is 280~320℃. The temperature rise to the reaction temperature is 500℃~700℃, preferably 550℃~600℃; the reaction pressure is 0.5~3.0MPa, preferably 0.5~1.5MPa; and the reaction time is 0.5h~3h, preferably 1h~2.5h. The reaction is carried out under stirring at a speed of 300~500r / min. The temperature rise is programmed, with a heating rate of 2~5℃ / min. Rapid cooling can be performed by injecting liquid nitrogen; the refining treatment is carried out in a grinding mill. Furthermore, after grinding, the product is passed through a 100-mesh (0.147mm) standard sieve, and the sieved product is stored at -18℃ to -30℃ for later use.

[0041] The performance modifier is waste activated carbon adsorbent, which was previously used specifically to adsorb organic waste gas from refineries. This waste activated carbon adsorbent adsorbed a large amount of organic waste gas (including aliphatic and aromatic hydrocarbons, alcohols, lipids, ketones, etc.), catalyst solid particles, and soot. The activated carbon adsorbent is preferably activated carbon containing copper and / or iron ions (the total mass of copper and / or iron ions accounts for 1% to 10% of the activated carbon mass, preferably 2% to 8%). Specifically, micropores (<2nm) account for 20% to 40% of the total pore volume, mesopores (2nm to 50nm) account for 10% to 25%, and macropores (>50nm) account for 35% to 70%.

[0042] A second aspect of this invention provides a method for preparing modified bitumen for water-based drilling fluids, comprising:

[0043] (1) Add the inferior slag heated to a fluid state, oil sand asphalt, and pretreatment agent to the reactor, stir and heat to the reaction temperature, and keep it warm after the reaction is completed; after the heat preservation is completed, perform depressurization deep drawing to obtain the pretreated slag.

[0044] (2) Add anhydride modifier and initiator to the material obtained in step (1), stir and heat to the reaction temperature, and carry out the reaction under protective gas;

[0045] (3) Add stabilizer to the material obtained in step (2), stir and heat to the reaction temperature, and carry out the reaction under protective gas; after the reaction is completed, add modifier and modifier, and continue the reaction;

[0046] (4) Transfer the material obtained in step (3) into an oxidation reactor, add a performance regulator, and introduce an oxidizing gas under stirring to carry out an oxidation reaction. After the reaction is completed, modified bitumen for water-based drilling fluid is obtained.

[0047] In step (1), the temperature at which the inferior slag is heated to a fluid state is 140℃~155℃.

[0048] In step (1), the reactor is a high-pressure reactor, and the initial temperature of the reactor is adjusted to 130℃~150℃.

[0049] In step (1), the stirring speed is 600-800 r / min. The heating to the reaction temperature is performed using a programmed temperature rise method, with a heating rate of 1℃-3℃ / min. The reaction temperature is 140℃-180℃, preferably 155℃-170℃. The reaction time is 3-6 h.

[0050] In step (1), the conditions for the heat preservation treatment are: heat preservation at 120℃~135℃ for 10~16h.

[0051] In step (1), the termination temperature of the decompression deep drawing is 453℃~460℃ (the converted ambient pressure temperature).

[0052] In step (2), the stirring speed is 600–800 r / min. Heating to the reaction temperature is performed using a programmed temperature rise method at a rate of 1–3 °C / min. The reaction temperature is 160–180 °C, and the reaction time is 6–8 h. The protective gas is an inert gas and / or N2. The amount of protective gas is such that the pressure inside the reactor is maintained at 0.3–0.9 MPa, preferably 0.5–0.9 MPa.

[0053] In step (3), after adding the stabilizer, the stirring speed is 300-600 r / min, the reaction temperature is 130℃-145℃, and the reaction time is 3-6 h. After adding the modifier, the reaction temperature is 140℃-180℃, preferably 150℃-175℃, and the reaction is continued for 0.5-1.5 h after adding the modifier for 2-4 h.

[0054] In step (3), the protective gas is an inert gas and / or N2. The amount of the protective gas is such that the pressure inside the reactor is maintained at 0.3–0.9 MPa, preferably 0.4–0.8 MPa.

[0055] In step (3), the preparation process of the modified additive is as follows:

[0056] The dried elemental sulfur is added to a closed reactor, stirred and heated to produce sulfur vapor, and then heated to the reaction temperature to carry out the reaction. After the reaction is completed, the mixture is rapidly cooled and refined to obtain the final modified additive.

[0057] Further, the drying conditions are as follows: sulfur is dried at 55℃~65℃ for 2h~4h. The sealed reactor is preferably a high-pressure reactor, and before use, it is purged with nitrogen for 10~30min to ensure no air is present during the reaction. The heating temperature required for sulfur vapor is 280~320℃. The temperature rise to the reaction temperature is 500℃~700℃, preferably 550℃~600℃; the reaction pressure is 0.5~3.0MPa, preferably 0.5~1.5MPa; and the reaction time is 0.5h~3h, preferably 1h~2.5h. The reaction is carried out under stirring at a speed of 300~500r / min. The temperature rise is programmed, with a heating rate of 2~5℃ / min. Rapid cooling can be performed by injecting liquid nitrogen; the refining treatment is carried out in a grinding mill. Furthermore, after grinding, the product is passed through a 100-mesh (0.147mm) standard sieve, and the sieved product is stored at -18℃ to -30℃ for later use.

[0058] In step (4), the performance regulator is first treated with water before use. Specifically, the performance regulator is soaked in distilled water for 15 to 24 hours and then dried before use.

[0059] In step (4), the oxidizing gas is oxygen-enriched air (oxygen volume content of 30%–55%), and the gas flow rate is 0.06–0.4 m³ / s. 3 / kg / h; the temperature of the oxidation reaction is 210℃~320℃, preferably 220℃~300℃, the time of the oxidation reaction is 4~8h, and the stirring speed during the oxidation process is 50~200r / min.

[0060] The obtained water-based drilling fluid is cryogenically pulverized with modified bitumen to obtain modified bitumen for drilling fluid.

[0061] The freezing temperature is -15℃ to -45℃, preferably -20℃ to -35℃, and the freezing time is 6 to 24 hours, preferably 12 to 24 hours.

[0062] The pulverization process is carried out in equipment such as high-speed shear pulverizer, colloid mill, and ball mill, and the pulverization time is 30-100s, preferably 30-60s.

[0063] Compared with the prior art, the present invention has the following advantages:

[0064] (1) The inferior slag reducing agent and oil sand asphalt used in this invention are both low-value-added raw materials, which are not suitable for producing high-grade road asphalt. For example, Tarim slag reducing agent and Inner Mongolia oil sand asphalt have high asphalt content, very special forms, and extremely poor comprehensive performance. The two raw materials have special properties and complement each other. After pretreatment and decompression deep drawing, their composition structure is further optimized, which greatly improves the high-temperature softening point and hydrophilicity of the raw materials. After subsequent modification treatment, they can be used to prepare high softening point asphalt for drilling fluid, which expands the use of inferior raw materials and increases their added value.

[0065] (2) The pre-treated slag with a specific composition is modified by anhydride modification, which not only increases the reactive sites and contact area between the anhydride and the asphalt, making the Diels-Alder reaction between the anhydride and the asphalt easier, but also greatly increases the polarity of the asphalt surface, enhances the π-π charge transfer and hydrogen bonding, and effectively increases the conversion rate of the anhydride reaction.

[0066] (3) The modifier used in this invention can react with the active components in asphalt, which can not only adjust the composition structure of asphalt, but also greatly improve the hydrophilicity of asphalt. In addition, the generation of toxic and harmful gases such as H2S is inhibited during the reaction process, reducing the harm to the environment and human health. The modifier effectively promotes the reaction process, thereby improving the conversion rate and stability of the reaction. After the reaction, the stabilizer further improves the hydrophilicity of the material and its adhesion to the well wall, and is resistant to high temperature, hard water, inorganic salts, etc., making it suitable for complex downhole environments.

[0067] (4) The performance modifier introduced in this invention contains loaded metals, catalyst particles, and dust particles, which can act as catalysts for the oxidation reaction, accelerating the oxidation process. The adsorbed organic matter makes it more uniformly dispersed in the asphalt. After water treatment, the water adsorbed by the pore structure of different sizes rapidly vaporizes, increasing the contact area between the oxygen-rich gas and the asphalt, thus improving the reaction rate. The addition of activated carbon further enhances the high-temperature stability of the asphalt. Furthermore, the performance modifier used in this invention is a refinery solid waste, making it low-cost and environmentally friendly. Detailed Implementation

[0068] The technical solution of the present invention is further described below through embodiments, but these embodiments cannot limit the scope of protection of the present invention, and the percentages involved are mass fractions.

[0069] In this invention, the softening point is tested according to the requirements of the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering JTG E20-2011", the contact angle is measured using the OCA25 video optical contact angle measuring instrument developed and manufactured by Dataphysics GmbH, Germany, and the high-temperature and high-pressure filtration loss is determined according to the SY / T5621 method.

[0070] Example 1

[0071] Preparation of modified additives:

[0072] Sublimed sulfur, dried in an oven at 60°C for 2.5 hours, was added to a high-pressure reactor that had been purged with nitrogen for 30 minutes. The reactor was heated to sulfur vapor at 300°C and then heated to 560°C at a programmed rate of 5°C / min. The reactor was then stirred at 450 r / min for 2 hours, with the pressure maintained at 1.2 MPa during the reaction. After the reaction was completed, the reactor was injected into a liquid nitrogen atmosphere for rapid cooling. The cooled solid product was then ground and passed through a 100-mesh (0.147 mm) standard sieve. The sieved product was collected and stored at -25°C for later use.

[0073] Preparation of modified bitumen for drilling fluids:

[0074] (1) 100 parts of Tarim Basin slag heated to a fluid state (properties shown in Table 1) and 40 parts of Inner Mongolia oil sand asphalt (properties shown in Table 2) were added to a high-pressure reactor at 130℃ and stirred. 0.4 parts of polyphosphoric acid with a phosphoric acid content (calculated as H3PO4) of 135% were slowly added to the reactor (completed within 3 min). The temperature was increased to 160℃ at a stirring speed of 600 r / min and a speed program of 2℃ / min for 4 h. After the reaction, the reactor was placed in a heat treatment vessel and kept at 120℃ for 10 h. After the heat treatment, vacuum extraction was performed to obtain vacuum residue oil with a temperature greater than 455℃.

[0075] (2) Add 4 parts maleic anhydride and 0.5 parts dicumyl peroxide to the vacuum residue obtained in step (1). At a stirring speed of 650 r / min, the temperature is increased to 175°C at a speed of 2°C / min. After the temperature is increased, the reaction is carried out in a N2 atmosphere. The pressure in the reactor is maintained at 0.6 MPa and the reaction time is 6 h.

[0076] (3) Add 1.0 part of stabilizer (a mixture of polyphosphoric acid, lauryl alcohol polyoxyethylene ether, and hexadecyl alcohol polyoxyethylene ether, wherein, based on the total mass of the stabilizer, polyphosphoric acid (phosphoric acid (calculated as H3PO4) content is 105%) accounts for 30%, lauryl alcohol polyoxyethylene ether accounts for 30%, and hexadecyl alcohol polyoxyethylene ether accounts for 40%) to the material obtained in step (2). React at 130℃ for 4 hours. After the reaction is completed, raise the temperature to 155℃ and add 8 parts of modifier (sulfur content is 88.26wt%, rhombic sulfur content is 90.41wt% (accounting for the total sulfur content), trace element content is 2.82wt%, and total tar organic matter content is 1.82wt%). After reacting for 0.5 hours, add 2 parts of the modified additive prepared above and continue the reaction for 3 hours. All reactions are carried out under N2 atmosphere, the pressure in the reactor is maintained at 0.8MPa, and the stirring speed is 600r / min.

[0077] (4) Transfer the material obtained in step (3) into the oxidation reactor, add 6 parts of waste activated carbon adsorbent (micropores account for 25%, mesopores account for 15%, and macropores account for 60%, the activated carbon adsorbent is loaded with copper and iron ions, and has adsorbed a large amount of organic waste gas) soaked in distilled water for 15 hours, and introduce oxygen-enriched air (oxygen volume content is 45%) at a stirring speed of 100 r / min, with a gas flow rate of 0.15 m 3 / kg / h, oxidation temperature of 260℃, oxidation time of 5h, to obtain modified bitumen for drilling fluid.

[0078] (5) 100g of low-temperature frozen drilling fluid modified bitumen (low-temperature freezing conditions: temperature -30℃, time 12h) was added to a high-speed pulverizer and pulverized for 30s to obtain drilling fluid modified bitumen particles A1 with an average particle size of 80um.

[0079] Example 2

[0080] (1) 100 parts of Tarim Basin slag heated to a fluid state (properties shown in Table 1) and 40 parts of Inner Mongolia oil sand asphalt (properties shown in Table 2) were added to a high-pressure reactor at 130℃ and stirred. 0.2 parts of polyphosphoric acid with a phosphoric acid content (calculated as H3PO4) of 135% were slowly added to the reactor (completed within 3 min). The temperature was increased to 160℃ at a stirring speed of 600 r / min and a speed program of 2℃ / min for 4 h. After the reaction, the reactor was placed in a pressure vessel for heat preservation at 130℃ for 12 h. After heat preservation, vacuum extraction was performed to obtain vacuum residue oil with a temperature greater than 455℃.

[0081] (2) Add 4.75 parts of tung oil anhydride and 0.6 parts of dicumyl peroxide to the vacuum residue obtained in step (1). At a stirring speed of 650 r / min, the temperature is increased to 175°C at a speed of 2°C / min. After the temperature is increased, the reaction is carried out in a N2 atmosphere. The pressure in the reactor is maintained at 0.6 MPa and the reaction time is 6 h.

[0082] (3) Add 1.0 part of stabilizer (a mixture of polyphosphoric acid, lauryl alcohol polyoxyethylene ether and hexadecyl alcohol polyoxyethylene ether, wherein, based on the total mass of the stabilizer, polyphosphoric acid (phosphoric acid (calculated as H3PO4) content is 105%) accounts for 30%, lauryl alcohol polyoxyethylene ether accounts for 30%, and hexadecyl alcohol polyoxyethylene ether accounts for 40%), and react at 130°C for 4 hours. After the reaction is completed, raise the temperature to 160°C and add 10 parts of modifier (preparation method is the same as in Example 1). After reacting for 1 hour, add 2.5 parts of modifier (preparation method is the same as in Example 1) and continue to react for 3 hours. All reactions are carried out under N2 atmosphere, the pressure in the reactor is maintained at 0.8 MPa, and the stirring speed is 600 r / min.

[0083] (4) Transfer the material obtained in step (3) into the oxidation reactor, add 6 parts of waste activated carbon adsorbent (micropores account for 25%, mesopores account for 15%, and macropores account for 60%, the activated carbon adsorbent is loaded with copper and iron ions, and has adsorbed a large amount of organic waste gas) that has been soaked in distilled water for 24 hours, and introduce oxygen-enriched air (oxygen volume content is 45%) at a stirring speed of 100 r / min, with a gas flow rate of 0.15 m 3 / kg / h, oxidation temperature of 280℃, oxidation time of 4h, to obtain modified bitumen for drilling fluid.

[0084] (5) 100g of low-temperature frozen modified bitumen for drilling fluid (low-temperature freezing conditions: temperature -32℃, time 10h) was added to a high-speed pulverizer and pulverized for 40s to obtain drilling fluid modified bitumen particles A2 with an average particle size of 85um.

[0085] Example 3

[0086] (1) 100 parts of Tarim Basin slag heated to a fluid state (properties shown in Table 1) and 35 parts of Inner Mongolia oil sand asphalt (properties shown in Table 2) were added to a high-pressure reactor at 130℃ and stirred. 0.4 parts of polyphosphoric acid with a phosphoric acid content (calculated as H3PO4) of 135% were slowly added to the reactor (completed within 3 min). The temperature was increased to 160℃ at a stirring speed of 600 r / min and a speed program of 2℃ / min for 4 h. After the reaction, the reactor was placed in a heat treatment vessel and kept at 120℃ for 10 h. After the heat treatment, vacuum extraction was performed to obtain vacuum residue oil with a temperature greater than 455℃.

[0087] (2) Add 5 parts maleic anhydride, 0.5 parts dicumyl peroxide and 0.1 parts azobisisobutyronitrile to the vacuum residue obtained in step (1). At a stirring speed of 650 r / min, the temperature is increased to 170°C at a speed program of 2°C / min. After the temperature is increased, the reaction is carried out in a N2 atmosphere. The pressure in the reactor is maintained at 0.6 MPa and the reaction time is 6 h.

[0088] (3) Add 1.2 parts of stabilizer (a mixture of polyphosphoric acid, lauryl alcohol polyoxyethylene ether, and nonylphenol polyoxyethylene ether, wherein, based on the total mass of the stabilizer, polyphosphoric acid (phosphoric acid (calculated as H3PO4) content is 105%) accounts for 35%, lauryl alcohol polyoxyethylene ether accounts for 25%, and nonylphenol polyoxyethylene ether accounts for 40%), and react at 130℃ for 4 hours. After the reaction is completed, raise the temperature to 150℃ and add 8 parts (sulfur content is 87.48wt%, rhombic sulfur content is 90.25wt% (accounting for the total sulfur content), trace element content is 2.12wt%, and total tar organic matter content is 1.64wt%), and react for 1 hour. Then add 3 parts of modifying agent (preparation method is the same as in Example 1) and continue the reaction for 2.5 hours. All reactions are carried out under N2 atmosphere, the pressure in the reactor is maintained at 0.8MPa, and the stirring speed is 600r / min.

[0089] (4) Transfer the material obtained in step (3) into the oxidation reactor, add 8 parts of waste activated carbon adsorbent (micropores account for 30%, mesopores account for 15%, and macropores account for 55%, the activated carbon adsorbent is loaded with copper and iron ions, and has adsorbed a large amount of organic waste gas) that has been soaked in distilled water for 18 hours, and introduce oxygen-enriched air (oxygen volume content is 50%) at a stirring speed of 150 r / min, with a gas flow rate of 0.2 m 3 / kg / h, oxidation temperature of 240℃, oxidation time of 6h, to obtain modified bitumen for drilling fluid.

[0090] (5) Add 100g of low-temperature frozen modified bitumen for drilling fluid (low-temperature freezing conditions: temperature -35℃, time 14h) to a high-speed pulverizer and pulverize for 30s to obtain drilling fluid modified bitumen particles A3 with an average particle size of 95um.

[0091] Example 4

[0092] (1) 100 parts of Tarim Basin slag heated to a fluid state (properties shown in Table 1) and 50 parts of Inner Mongolia oil sand asphalt (properties shown in Table 2) were added to a high-pressure reactor at 130℃ and stirred. 0.6 parts of polyphosphoric acid with a phosphoric acid content (calculated as H3PO4) of 135% were slowly added to the reactor (completed within 3 min). The temperature was increased to 160℃ at a stirring speed of 600 r / min and a speed program of 2℃ / min for 4 h. After the reaction, the reactor was placed in a heat treatment vessel and kept at 120℃ for 10 h. After the heat treatment, vacuum extraction was performed to obtain vacuum residue oil with a temperature greater than 455℃.

[0093] (2) Add 4.6 parts of maleic anhydride, 0.5 parts of dicumyl peroxide and 0.1 parts of azobisisobutyronitrile to the vacuum residue obtained in step (1). At a stirring speed of 650 r / min, the temperature is increased to 170°C at a speed program of 2°C / min. After the temperature is increased, the reaction is carried out in a N2 atmosphere. The pressure in the reactor is maintained at 0.6 MPa and the reaction time is 6 h.

[0094] (3) Add 1.1 parts of stabilizer (a mixture of polyphosphoric acid, lauryl alcohol polyoxyethylene ether, and nonylphenol polyoxyethylene ether, wherein, based on the total mass of the stabilizer, polyphosphoric acid (phosphoric acid (calculated as H3PO4) content is 105%) accounts for 35%, lauryl alcohol polyoxyethylene ether accounts for 25%, and nonylphenol polyoxyethylene ether accounts for 40%), and react at 130°C for 4 hours. After the reaction is completed, raise the temperature to 160°C and add 9 parts of modifier (properties as in Example 3). After reacting for 0.5 hours, add 3 parts of modifier (preparation method is the same as in Example 1) and continue to react for 3 hours. All reactions are carried out under N2 atmosphere, the pressure in the reactor is maintained at 0.8 MPa, and the stirring speed is 600 r / min.

[0095] (4) Transfer the material obtained in step (3) into the oxidation reactor, add 7 parts of waste activated carbon adsorbent (micropores account for 30%, mesopores account for 15%, and macropores account for 55%, the activated carbon adsorbent is loaded with copper and iron ions, and has adsorbed a large amount of organic waste gas) that has been soaked in distilled water for 18 hours, and introduce oxygen-enriched air (oxygen volume content is 50%) at a stirring speed of 150 r / min, with a gas flow rate of 0.2 m 3 / kg / h, oxidation temperature of 240℃, oxidation time of 6h, to obtain modified bitumen for drilling fluid.

[0096] (5) Add 100g of low-temperature frozen modified bitumen for drilling fluid (low-temperature freezing conditions: temperature -30℃, time 20h) to a high-speed pulverizer and pulverize for 30s to obtain drilling fluid modified bitumen particles A4 with an average particle size of 85um.

[0097] Example 5

[0098] Preparation of modified additives:

[0099] Sublimed sulfur, dried in an oven at 60°C for 3 hours, was added to a high-pressure reactor that had been purged with nitrogen for 30 minutes. The reactor was heated to sulfur vapor at 320°C and then heated to 580°C at a programmed rate of 5°C / min. The reactor was then stirred at 450 r / min for 2.5 hours, with the pressure maintained at 1.5 MPa during the reaction. After the reaction was completed, the reactor was injected into a liquid nitrogen atmosphere for rapid cooling. The cooled solid product was then ground and passed through a 100-mesh (0.147 mm) standard sieve. The sieved product was collected and stored at -20°C for later use.

[0100] Preparation of modified bitumen for drilling fluids:

[0101] (1) 100 parts of Tarim Basin slag heated to a fluid state (properties shown in Table 1) and 40 parts of Inner Mongolia oil sand asphalt (properties shown in Table 2) were added to a high-pressure reactor at 145℃ and stirred. 0.6 parts of polyphosphoric acid with a phosphoric acid content (calculated as H3PO4) of 135% were slowly added to the reactor (completed within 3 min). The temperature was increased to 160℃ at a stirring speed of 600 r / min and a program speed of 2℃ / min for 4 h. After the reaction, the reactor was placed in a heat treatment vessel and kept at 120℃ for 10 h. After the heat treatment, vacuum extraction was performed to obtain vacuum residue oil with a temperature greater than 455℃.

[0102] (2) Add 5.5 parts maleic anhydride and 0.6 parts dicumyl peroxide to the vacuum residue obtained in step (1). At a stirring speed of 650 r / min, the temperature is increased to 175°C at a speed of 2°C / min. After the temperature is increased, the reaction is carried out in a N2 atmosphere. The pressure in the reactor is maintained at 0.6 MPa and the reaction time is 6 h.

[0103] (3) Add 1.0 part of stabilizer (a mixture of polyphosphoric acid, lauryl alcohol polyoxyethylene ether, and hexadecyl alcohol polyoxyethylene ether, wherein, based on the total mass of the stabilizer, polyphosphoric acid (phosphoric acid (calculated as H3PO4) content is 105%) accounts for 30%, lauryl alcohol polyoxyethylene ether accounts for 30%, and hexadecyl alcohol polyoxyethylene ether accounts for 40%) to the material obtained in step (2). React at 135℃ for 5 hours. After the reaction is completed, raise the temperature to 165℃ and add 8 parts of modifier (sulfur content is 88.26wt%, rhombic sulfur content is 90.41wt% (accounting for the total sulfur content), trace element content is 2.82wt%, and total tar organic matter content is 1.82wt%). After reacting for 0.5 hours, add 2 parts of the modified additive prepared above and continue the reaction for 3 hours. All reactions are carried out under N2 atmosphere, the pressure in the reactor is maintained at 0.8MPa, and the stirring speed is 600r / min.

[0104] (4) Transfer the material obtained in step (3) into the oxidation reactor, add 7 parts of waste activated carbon adsorbent (micropores account for 25%, mesopores account for 15%, and macropores account for 60%, the activated carbon adsorbent is loaded with copper and iron ions, and has adsorbed a large amount of organic waste gas) soaked in distilled water for 15 hours, and introduce oxygen-enriched air (oxygen volume content is 45%) at a stirring speed of 100 r / min, with a gas flow rate of 0.15 m 3 / kg / h, oxidation temperature of 260℃, oxidation time of 5h, to obtain modified bitumen for drilling fluid.

[0105] (5) 100g of low-temperature frozen drilling fluid modified bitumen (low-temperature freezing conditions: temperature -30℃, time 12h) was added to a high-speed pulverizer and pulverized for 30s to obtain drilling fluid modified bitumen particles A5 with an average particle size of 85um.

[0106] Comparative Example 1

[0107] The process is the same as in Example 1, except that in step (1), 100 parts of Tarim Basin slag heated to a fluid state (properties shown in Table 1) and 40 parts of Inner Mongolia oil sand asphalt (properties shown in Table 2) are replaced with 140 parts of Tarim Basin slag heated to a fluid state (properties shown in Table 1) which are then added to a high-pressure reactor at a temperature of 130°C and stirred. Modified asphalt particles B1 are finally obtained.

[0108] Comparative Example 2

[0109] The process is the same as in Example 1, except that in step (1), 100 parts of Tarim Basin slag heated to a fluid state (properties shown in Table 1) and 40 parts of Inner Mongolia oil sand asphalt (properties shown in Table 2) are replaced with 140 parts of Inner Mongolia oil sand asphalt (properties shown in Table 2) which are added to a high-pressure reactor at a temperature of 130°C and stirred. Modified asphalt particles B2 are finally obtained.

[0110] Comparative Example 3

[0111] Same as Example 1, except that no modifier is added in step (3), and the modified asphalt particles B3 are finally obtained.

[0112] Comparative Example 4

[0113] Same as Example 1, except that step (4) is omitted in the preparation process, and the modified asphalt particles B4 are finally obtained.

[0114] Test case

[0115] The softening point, hydrophilicity, and high-temperature, high-pressure filtration loss of the modified asphalt materials obtained in the examples and comparative examples were tested. The modified asphalt particles obtained in the examples and comparative examples were added to the prepared base slurry, with the amount of modified asphalt particles accounting for 2% of the weight of the base slurry. The filtration loss was measured after aging at different temperatures (16 h) under a test pressure of 3.45 MPa. The specific results are shown in Table 3. The base slurry was prepared as follows: 2.75 g of anhydrous sodium carbonate was added to 1000 mL of water, followed by 60 g of bentonite. The mixture was stirred at high speed for 20 minutes and cured at room temperature for 24 hours to obtain a 6% freshwater base slurry.

[0116] Table 1. Properties of Tarim Basin Slag Reduction Materials Used in Examples and Comparative Cases

[0117] Carbon content / wt% 89.13 Nitrogen content / wt% 0.14 Hydrogen content / wt% 7.44 Sulfur content / wt% 3.13 Total nickel and vanadium content / ug / g 337 Saturation fraction / % 30.17 Aromatic components / % 28.11 Gel content / % 17.73 Asphalt content / % 23.99 Condensation Index (CI) 0.31 Colloidal Instability Index Ic 1.18 25℃ penetration / 0.1mm 51 Penetration Index (5 points) 1.81 Ductility at 25℃ / cm 62.4 Softening point / °C 57.8 Flash point / °C 253 Dynamic viscosity (60℃) / Pa.s 1680

[0118] Table 2 Properties of the oil sands bitumen used in the examples and comparative examples

[0119] Carbon content / wt% 84.64 Nitrogen content / wt% 0.30 Hydrogen content / wt% 10.08 Sulfur content / wt% 2.64 Hydrogen-to-carbon ratio 1.42 Saturation fraction / % 11.38 Aromatic components / % 35.21 Gel content / % 32.49 Asphalt content / % 20.92 Condensation Index (CI) 0.26 Ash content / wt% 1.758 Mechanical impurities / wt% 2.59 Pour point / °C 29.0 <![CDATA[Viscosity (100°C) / mm 2 ·s -1 > 1553 Flash point / °C 238 Softening point / °C 57

[0120] Table 3. Properties of the modified asphalt obtained in the examples and comparative examples.

[0121]

[0122]

[0123] The scope of protection of this invention is not limited to the above embodiments, but is defined by the claims. Those skilled in the art can make appropriate modifications to these embodiments without departing from the technical concept and spirit of this invention, and these modified embodiments are also included within the scope of protection of this invention.

Claims

1. A modified bitumen for water-based drilling fluid, characterized in that, By weight, it includes the following raw material components: Pretreatment for slag reduction: 100 portions; Anhydride modifier: 2-10 parts; Initiator: 0.08~0.8 parts; Stabilizer: 0.3~1.5 parts; Modifier: 3-15 parts; Modifying additives: 2-8 parts; Performance modifier: 0.5~12 parts; The modifier is low-grade sulfur; The pretreatment slag reduction, by weight, includes the following raw material components: Inferior slag reduction: 100 portions; Oil sand asphalt: 20-60 parts; Pretreatment agent: 0.1~2 parts; The anhydride modifier is one or more of maleic anhydride, polyisobutylene succinic anhydride, methyl nadic anhydride, dodecenyl succinic anhydride, tung oil anhydride or hydrolyzed polymaleic anhydride. The stabilizer includes polyphosphoric acid with low phosphoric acid content, and also contains at least one of lauryl alcohol polyoxyethylene ether, hexadecyl alcohol polyoxyethylene ether, octadecyl alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether, octylphenol polyoxyethylene ether, and dinonylphenol polyoxyethylene ether. The content of the low-phosphoric acid polyphosphoric acid is 20% to 50% by weight of the stabilizer; the low-phosphoric acid polyphosphoric acid contains 105% to 115% phosphoric acid by weight (H3PO4). The modified additive is a sulfur pretreatment agent. The preparation process of the modified additive is as follows: dried elemental sulfur is added to a closed reactor, stirred and heated to sulfur vapor, and then heated to the reaction temperature to carry out the reaction. After the reaction is completed, it is rapidly cooled and refined to obtain the final modified additive. The performance modifier is waste activated carbon adsorbent; the waste activated carbon is activated carbon containing copper ions and / or iron ions; The pretreatment agent is a high-phosphoric acid polyphosphoric acid, wherein the phosphoric acid content, calculated as H3PO4, is 125%~145% by mass. The preparation method of the pretreated slag includes: adding inferior slag heated to a fluid state, oil sand asphalt, and pretreatment agent into a reaction vessel, stirring and heating to the reaction temperature, and then keeping it warm after the reaction is completed; After the heat preservation is completed, decompression and deep drawing are carried out to obtain pre-treated slag-reduced material.

2. The modified asphalt for water-based drilling fluid according to claim 1, characterized in that, The initiator is one or more of dicumyl peroxide, tert-butyl hydroperoxide, benzoyl peroxide, sodium metabisulfite, azobisisobutyronitrile, azobisisoheptanenitrile, and cumyl hydroperoxide.

3. The modified asphalt for water-based drilling fluid according to claim 1, characterized in that, The activated carbon containing copper ions and / or iron ions, wherein micropores <2nm account for 20%~40% of the total pore volume, mesopores 2nm~50nm account for 10%~25% of the total pore volume, and macropores >50nm account for 35%~70% of the total pore volume.

4. The modified asphalt for water-based drilling fluid according to claim 1, characterized in that, The properties of the inferior slag include: a flash point of 241℃~256℃, a sulfur content of 2.61wt%~3.65wt%, and by mass fraction, saturated components of 26.1%~37.7%, aromatic components of 20.2%~34.5%, resins of 18.3%~24.8%, and asphaltene of 21.3%~30.1%.

5. The modified asphalt for water-based drilling fluid according to claim 4, characterized in that, The inferior slag, by mass fraction, contains 21.3% to 26.0% asphalt.

6. The modified bitumen for water-based drilling fluid according to claim 4, characterized in that, The inferior slag has the following properties: residual carbon value of 21wt%~29wt%, nitrogen content of 0.14wt%~0.61wt%, total nickel and vanadium content of 320~365μg / g, and condensation index CI of 0.26~0.

35.

7. The modified bitumen for water-based drilling fluid according to claim 1, characterized in that, The oil sands asphalt is one or more of the following: Inner Mongolia oil sands asphalt, Qinghai oil sands asphalt, Indonesian oil sands asphalt, and Kazakhstani oil sands asphalt.

8. The modified bitumen for water-based drilling fluid according to claim 7, characterized in that, The properties of the oil sands bitumen include: softening point not less than 50℃, flash point not less than 232℃, pour point of 25℃~32℃, and viscosity of 1450~1600 mmol / L at 100℃. 2 .S -1 The residual carbon content is 9.5wt%~15.1wt%, the sulfur content is 2.0wt%~6.1wt%, the carbon content is 84wt%~87wt%, the hydrogen content is 10wt%~12.4wt%, and the nitrogen content is 0.2wt%~0.8wt%. By mass fraction, the saturated components account for 10.1%~30.7%, the aromatic components account for 15.6%~35.9%, the resins account for 30.4%~45.8%, and the asphaltenes account for 10.7%~27.3%.

9. The modified asphalt for water-based drilling fluid according to claim 8, characterized in that, The properties of the oil sands bitumen include: softening point of 55℃~65℃, flash point of 235℃~256℃, and viscosity of 1500~1600 mmol / L at 100℃. 2 .S -1 By mass fraction, asphalt content ranges from 11.3% to 25.2%.

10. A method for preparing modified bitumen for water-based drilling fluid according to any one of claims 1-9, comprising: (1) Add the inferior slag heated to a fluid state, oil sand asphalt, and pretreatment agent into the reactor, stir and heat to the reaction temperature, and keep warm after the reaction is completed; After the insulation is completed, decompression and deep drawing are performed to obtain pre-treated slag-reduced material. (2) Add anhydride modifier and initiator to the material obtained in step (1), stir and heat to the reaction temperature, and carry out the reaction under protective gas; (3) Add stabilizer to the material obtained in step (2), stir and heat to the reaction temperature, and carry out the reaction under protective gas; after the reaction is completed, add modifier and modifier, and continue the reaction; (4) Transfer the material obtained in step (3) into an oxidation reactor, add a performance regulator, and introduce an oxidizing gas under stirring to carry out an oxidation reaction. After the reaction is completed, modified bitumen for water-based drilling fluid is obtained.

11. The method according to claim 10, characterized in that, In step (1), the stirring speed is 600~800 r / min; the heating to the reaction temperature is performed using a programmed temperature rise method at a rate of 1℃~3℃ / min, the reaction temperature is 140℃~180℃, and the reaction time is 3~6 h; and / or, The heat preservation treatment conditions are: heat preservation at 120℃~135℃ for 10~16 hours; and / or, The termination temperature for the decompression deep drawing is 453℃~460℃.

12. The method according to claim 10, characterized in that, In step (2), the stirring speed is 600~800 r / min; the heating to the reaction temperature is performed by programmed heating at a rate of 1℃~3℃ / min; the reaction temperature is 160℃~180℃, and the reaction time is 6~8h; the protective gas is an inert gas and / or N2; the amount of protective gas is such that the pressure inside the reactor is maintained at 0.3~0.9MPa.

13. The method according to claim 10, characterized in that, In step (3), after adding the stabilizer, the stirring speed is 300~600 r / min, the reaction temperature is 130℃~145℃, and the reaction time is 3~6 h. After adding the modifier, the reaction temperature is 140℃~180℃. After reacting for 0.5~1.5 h, the modifier is added and the reaction continues for 2~4 h; and / or, In step (3), the protective gas is an inert gas and / or N2, and the amount of the protective gas is such that the pressure inside the reactor is maintained at 0.3~0.9MPa.

14. The method according to claim 10, characterized in that, In step (4), the performance regulator is first treated with water before use, specifically by soaking the performance regulator in distilled water for 15-24 hours, then air-drying it for later use; and / or, The oxidizing gas is oxygen-enriched air, with a flow rate of 0.06~0.4 m³ / h. 3 / kg / h; the oxidation reaction temperature is 210℃~320℃, the oxidation reaction time is 4~8h, and the stirring speed during the oxidation process is 50~200r / min.

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