An asphalt composition for drilling fluids and a method for preparing the same

Abstract

The application discloses a kind of drilling fluid asphalt compositions and preparation method thereof.The drilling fluid asphalt composition of the application includes the following raw material components: asphalt shell component and asphalt core component, wherein the asphalt shell component includes the following raw material components by weight: inferior residue reduction: 100 parts; Oil sand asphalt: 20-60 parts; Modifier: 0.1-2 parts; Wherein the asphalt core component includes the following raw material components by weight: ethylene tar heavy component: 100 parts; Pretreatment agent: 3-12 parts; Performance regulator: 0.5-8 parts.The application uses difficult-to-handle inferior residue reduction, oil sand treatment agent asphalt, ethylene tar as raw material, and obtains high softening point asphalt suitable for drilling fluid system after modification treatment, which is suitable as the main material for producing asphalt drilling fluid.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of bitumen, in particular to a bitumen composition for drilling fluid and a preparation method thereof. BACKGROUND

[0002] With the increasing heaviness of crude oil, the yield of vacuum residue is gradually increased, the content of heavy metals and sulfur in the residue is increased, the relative content of saturates and asphaltene in the residue is increased, the relative content of aromatic and resin is decreased, and the association degree of asphaltene is increased, and the existence form is more complex. It is more difficult to directly produce high-grade bitumen from poor-quality residue. Ethylene tar is a byproduct of ethylene production by cracking of ethylene raw material. With the rapid development of China's ethylene industry, the production of ethylene tar is also increasing year by year. Ethylene tar is relatively complex in composition, especially high in asphaltene content, which is difficult to utilize. A large part of it is used as fuel, which not only wastes resources but also is not conducive to energy conservation and environmental protection.

[0003] With the continuous expansion of the drilling field, the application of bitumen plugging agent in oilfield drilling is paid more and more attention. Bitumen plugging agent generally contains water-insoluble bitumen particles and has a certain softening point. When the temperature and pressure in the wellbore are high enough, the bitumen particles soften and deform, and are squeezed into the microcracks of the well wall, preventing the drilling fluid from penetrating through the microcracks and effectively plugging the formation together with the mud cake. Bitumen is an extremely effective anti-sloughing agent and reservoir protection agent for oil drilling. For deep oil and gas field drilling operations, generally softening point bitumen cannot meet the high temperature operation requirements of deep wells due to excessive softening or flowing. High softening point bitumen (softening point above 100℃, especially above 120℃) can meet the requirements of deep drilling due to its excellent high temperature resistance.

[0004] If the increasingly poor quality of residue and the difficult-to-use ethylene tar can be modified to obtain high softening point bitumen suitable for drilling fluid system, it will be a good choice.

[0005] CN1415699A discloses a production method of oxidized bitumen. First, air and bitumen are mixed by using a static mixer to disperse air into bitumen raw material in the form of small bubbles, and then enter the oxidation device for oxidation reaction. This method can adjust the performance of bitumen when producing ordinary road bitumen and building bitumen, but it is not suitable for producing high softening point bitumen. Because the amount of air existing in bitumen at high temperature is very small, the oxidation efficiency is limited, and the softening point of bitumen cannot be greatly improved, and coking phenomenon exists in 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 coal tar pitch, such as low viscosity and high reactivity 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.

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

[0008] To address the shortcomings of existing technologies, this invention provides a bitumen composition for drilling fluids and its preparation method. This invention uses difficult-to-process, low-quality slag-reducing materials, oil sands bitumen, and ethylene tar as raw materials, and through modification treatment, obtains a high softening point bitumen suitable for drilling fluid systems, making it suitable as a primary material for producing bitumen-based drilling fluids.

[0009] The first aspect of the present invention provides a bitumen composition for drilling fluid, comprising the following raw material components by weight: bitumen shell component: 100 parts; bitumen core component: 20-60 parts, preferably 30-60 parts;

[0010] The asphalt shell component, by weight, includes the following raw material components: inferior slag: 100 parts; oil sand asphalt: 20-60 parts, preferably 30-50 parts; modifier: 0.1-2 parts, preferably 0.2-1.2 parts;

[0011] The asphalt core component, by weight, includes the following raw material components: ethylene tar heavy component: 100 parts; pretreatment agent: 3 to 12 parts, preferably 3 to 10 parts; performance regulator: 0.5 to 8 parts, preferably 1 to 7 parts.

[0012] The softening point of the asphalt shell is 102–125°C, and the softening point of the asphalt core is 190–230°C.

[0013] 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%.

[0014] 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.

[0015] The poor residue can be Tahe residue or other residue meeting the above properties, and the poor residue is a fraction with an initial boiling point greater than 425℃.

[0016] The oil sand bitumen is one or more of Inner Mongolia oil sand bitumen, Qinghai oil sand bitumen, Indonesia oil sand bitumen and Kazakhstan oil sand bitumen.

[0017] The properties of the oil sand bitumen include: a softening point not less than 50℃, preferably 55℃-65℃, a flash point not less than 232℃, preferably 235℃-256℃, a freezing point of 25℃-32℃, a 100℃ viscosity of 1450-1600mm 2 .S -1 , preferably 1500-1600mm 2 .S -1 , a carbon residue of 9.5wt%-15.1wt%, a sulfur content of 2.0wt%-6.1wt%, a carbon content of 84wt%-87wt%, a hydrogen content of 10wt%-12.4wt%, a nitrogen content of 0.2wt%-0.8wt%, and, in mass fraction, a saturates content of 10.1%-30.7%, an aromatic content of 15.6%-35.9%, a resin content of 30.4%-45.8%, and an asphaltene content of 10.7%-27.3%, and the asphaltene content is preferably 11.3%-25.2%.

[0018] The modifier is polyphosphoric acid, and the mass content of phosphoric acid contained in the polyphosphoric acid is 125%-145%, preferably 130%-140% in terms of H3PO4.

[0019] The heavy component of ethylene tar is a heavy component greater than 340℃ obtained by vacuum distillation of ethylene tar.

[0020] The ethylene tar has the following properties: a carbon content of 91.2wt%-92.6wt%, a hydrogen content of 6.9wt%-7.4wt%, a nitrogen content of 0.03wt%-0.09wt%, an ash content not greater than 0.23wt%, a total mononuclear aromatic hydrocarbon content of 13.2wt%-15.1wt%, a total binuclear aromatic hydrocarbon content of 24.6wt%-27.3wt%, a total trinuclear aromatic hydrocarbon content of 14.4wt%-16.2wt%, a total tetranuclear aromatic hydrocarbon content of 10.8wt%-11.3wt%, a total pentanuclear aromatic hydrocarbon content of 5.2wt%-7.3wt%, and a resin content of 10.1wt%-12.7wt%, and a yield of a component greater than 340℃ of 65wt%-73wt%.

[0021] The pretreatment agent is one or more of p-xylylene glycol, p-toluene sulfonic acid, phosphoric acid, boric acid, sulfonic acid, dodecyl succinic anhydride, polyazelaic anhydride, polyglutaric anhydride, and polyoxalic anhydride.

[0022] The performance regulator is a spent activated carbon adsorbent which has been specially used for adsorbing organic waste gas of a refinery before being discarded. The spent activated carbon adsorbent has adsorbed a large amount of organic waste gas (including aliphatic and aromatic hydrocarbons, alcohols, lipids, ketones, etc.), catalyst solid particles, and smoke dust. The activated carbon adsorbent is preferably activated carbon containing copper ions and / or iron ions (the total mass of copper ions and / or iron ions accounts for 1% to 10% of the mass of the activated carbon, and preferably 2% to 8%).

[0023] The second aspect of the present application provides a preparation method of the asphalt composition for drilling fluid, comprising:

[0024] (1) adding the inferior reduced residue heated to a flow state, oil sand asphalt, and a modifier into a reaction kettle, stirring and heating to a reaction temperature, carrying out heat preservation treatment after the reaction is completed, and carrying out vacuum deep pulling after the heat preservation is completed to obtain an asphalt shell component;

[0025] (2) adding ethylene tar heavy components, a pretreatment agent, and a performance regulator heated to a flow state into an oxidation kettle to carry out oxidation treatment, carrying out condensation treatment after the oxidation treatment, and obtaining an asphalt core component after the treatment is completed;

[0026] (3) uniformly spraying the asphalt shell component heated to a flow state on the asphalt core component which is crushed into granular form to obtain the asphalt composition for drilling fluid.

[0027] In step (1), the temperature at which the inferior reduced residue is heated to a flow state is 140°C to 155°C.

[0028] In step (1), the reaction kettle is a high-pressure reaction kettle, and the initial temperature of the reaction kettle is adjusted to 130°C to 150°C.

[0029] In step (1), the stirring speed is 600 to 800 r / min. The heating to the reaction temperature is carried out by using programmed temperature rising, the temperature rising rate is 1°C to 3°C / min, the reaction temperature is 140°C to 180°C, and preferably 155°C to 170°C; and the reaction time is 3 to 6 h.

[0030] In step (1), the heat preservation treatment is carried out at 120°C to 135°C for 10 to 16 h.

[0031] In step (1), the end temperature of the reduced pressure deep cut is 453°C to 460°C (converted to normal pressure).

[0032] In step (2), the temperature at which the heavy ethylene tar fraction is heated to a flowable state is 170°C to 185°C. The performance modifier is water treated before use, specifically by soaking the performance modifier in distilled water for 15 to 24 hours, and then air drying.

[0033] In step (2), when the oxidation treatment is performed, an oxidizing gas is introduced. The oxidizing gas is oxygen-enriched air (oxygen content of 30% to 55% by volume), and the gas flow rate is 0.06 to 0.4 m 3 / kg / h; the temperature of the oxidation treatment is 220°C to 320°C, preferably 260°C to 300°C, and the time of the oxidation treatment is 150 to 240 minutes, with a stirring speed of 50 to 200 r / min during the oxidation treatment.

[0034] In step (2), the condensation temperature is 320°C to 380°C, preferably 350°C to 380°C, and the gas used during the condensation is an inert gas and / or N2, with a gas flow rate of 0.10 to 0.25 m 3 / kg / h, and the time of the condensation reaction is 200 to 260 minutes, with a stirring speed of 100 to 240 r / min during the condensation.

[0035] In step (3), the asphalt core particles are obtained by low-temperature freezing and pulverization, the freezing temperature is -15°C to -35°C, and the freezing time is 6 to 24 hours, preferably 10 to 20 hours. The pulverization is performed in a high-speed shearing pulverizer, a colloid mill, a ball mill pulverizer, or the like, the pulverization time is 20 to 90 seconds, preferably 30 to 80 seconds, and the pulverization particle size is 80 to 120 mesh.

[0036] In step (3), the spraying process can use equipment with a spraying function, such as a sprayer, and the material can be turned or mixed during the spraying process to allow the asphalt mother liquor to uniformly coat the surface of the asphalt core particles.

[0037] In step (3), the heating temperature of the asphalt shell component is 180°C to 210°C.

[0038] The obtained drilling fluid is subjected to low-temperature freezing and pulverization with the asphalt composition.

[0039] The freezing temperature is -15°C to -45°C, preferably -20°C to -35°C, and the freezing time is 6 to 24 hours, preferably 12 to 24 hours.

[0040] The pulverization process is carried out in a high-speed shearing pulverizer, a colloid mill, a ball mill pulverizer or the like, and the pulverization time is 30-100 seconds, preferably 30-60 seconds.

[0041] Compared with the prior art, the present application has the following advantages:

[0042] (1) The inferior residue and oil sand pitch used in the present application are low-value-added raw materials, which are not suitable for producing high-grade road pitch, such as the Tarim residue and Inner Mongolia oil sand pitch with high asphaltene content, very special existence form and extremely poor comprehensive performance. The two raw materials have special properties and cooperate with each other, and after pretreatment and deep vacuum extraction, the structure of the two is further optimized, which greatly improves the high-temperature softening point of the raw material, and can be used for preparing high-softening-point pitch for drilling fluid, expanding the use of inferior raw materials and improving the added value thereof.

[0043] (2) The ethylene tar used in the present application is a by-product heavy oil obtained by high-temperature cracking of long-chain hydrocarbons in the production of ethylene, which has low added value and is difficult to utilize. However, it has high asphaltene content and contains relatively rich fast-reacting components such as olefin bonds and alkyl side chains, which can be used for high-temperature and high-pressure environments in deep oil wells after oxidation and condensation with a pretreatment agent and a performance modifier.

[0044] (3) The pitch composition of the present application has a unique core-shell structure, and the shell and the core of the composition have different softening point ranges, which increases the viscoelastic use range and can be used in a wider pore size distribution range, thereby playing a good plugging and stabilizing well wall effect; the outer shell with medium and high softening point and the inner core with extremely high softening point can play a plugging role in different well depth environments and show good plugging effect in different formation temperature regions.

[0045] (4) The performance modifier introduced in the present application contains metal-loaded, catalyst particles, soot particles and the like which can be used as catalysts for oxidation reaction, thereby accelerating the oxidation reaction; the adsorbed organic matter makes it more uniformly dispersed in the pitch, and after water treatment, the water adsorbed in the pores of different sizes is quickly gasified, increasing the contact area between the oxygen-rich gas and the pitch and improving the reaction rate. The addition of activated carbon further improves the high-temperature stability of the pitch. Moreover, the performance modifier used in the present application belongs to refinery solid waste, which is low in cost and environmentally friendly. DETAILED DESCRIPTION

[0046] The technical solutions of the present application are further described below by way of examples, but these examples cannot limit the protection scope of the present application, and the % involved is the mass fraction.

[0047] In the present application, the softening point is tested according to the requirements of Highway Engineering Asphalt and Asphalt Mixture Test Regulation JTG E20-2011, and the high-temperature high-pressure filtration loss is determined according to the method of SY / T5621.

[0048] Example 1

[0049] (1) 100 parts of Tahe reduced residue (properties are shown in Table 1) heated to a flow state and 40 parts of Inner Mongolia oil sand asphalt (properties are shown in Table 2) were added to a high-pressure reaction kettle with a temperature of 130°C and stirred, and 0.4 parts of polyphosphoric acid with a phosphoric acid content (calculated as H3PO4) of 135% was slowly added to the reaction kettle (added within 3 min), and the temperature was programmed to rise to 160°C at a speed of 2°C / min under a stirring speed of 600 r / min, and the reaction time was 4 h; after the reaction was completed, the temperature was maintained in the reaction kettle, the temperature was 120°C, and the temperature maintaining time was 10 h. After the temperature maintaining was completed, vacuum deep-cutting was carried out, and vacuum residue greater than 455°C was obtained, that is, the asphalt shell component was obtained.

[0050] (2) 100 parts of ethylene tar heavy component (the ethylene tar heavy component used was a heavy component greater than 340°C obtained by vacuum distillation of ethylene tar with the properties shown in Table 3) heated to a flow state, 2 parts of terephthaldehyde, 3 parts of p-toluenesulfonic acid, and 6 parts of waste activated carbon adsorbent (25% micropores, 15% mesopores, and 60% macropores) soaked in distilled water for 15 h were added to an oxidation kettle, and oxygen-enriched air (oxygen content was 45%) was introduced at a gas flow rate of 0.15 m 3 / kg / h under a stirring state of 100 r / min, the oxidation temperature was 260°C, the oxidation time was 180 min, after the oxidation was completed, the temperature was raised to 360°C and N2 was introduced for condensation, the gas flow rate was 0.18 m 3 / kg / h, the condensation time was 240 min, and the stirring speed was 200 r / min, and the asphalt core component was obtained.

[0051] (3) 100 parts of the asphalt shell component heated to 190°C and having good fluidity were uniformly sprayed onto the surface of 50 parts of the asphalt core component particles crushed to 80-120 mesh at low temperature, and the asphalt composition was obtained.

[0052] (4) 100 g of the low-temperature frozen asphalt composition (low-temperature freezing conditions: temperature -30°C, time 12 h) was added to a high-speed pulverizer, and was pulverized for 30 s to obtain the drilling fluid asphalt composition particles A1, and the average particle size was 80 μm.

[0053] Example 2

[0054] (1) 100 parts of Tahe reduced residue (properties are shown in Table 1) heated to a flowable state and 40 parts of Inner Mongolia oil sand pitch (properties are shown in Table 2) were added to a high-pressure reaction kettle at a temperature of 130°C and stirred, 0.2 parts of polyphosphoric acid with a phosphoric acid content (calculated as H3PO4) of 135% was slowly added to the reaction kettle (added within 3 min), and the temperature was programmed to increase to 160°C at a rate of 2°C / min under stirring at a speed of 600 r / min, and the reaction time was 4 h; after the reaction was completed, the reaction kettle was placed in a heat preservation oven, the heat preservation temperature was 130°C, and the heat preservation time was 12 h. After the heat preservation was completed, vacuum deep-cutting was carried out, and vacuum residue greater than 455°C was obtained, i.e. the pitch shell component was obtained.

[0055] (2) 100 parts of ethylene tar heavy component (same as in Example 1) heated to a flowable state, 1 part of p-phenylenediamine, 3 parts of p-toluenesulfonic acid, and 6 parts of discarded activated carbon adsorbent (25% microporous, 15% mesoporous, and 60% macroporous) soaked in distilled water for 15 h (the activated carbon adsorbent was loaded with copper ions and iron ions and had adsorbed a large amount of organic waste gas) were added to an oxidation kettle, and oxygen-enriched air (oxygen content was 45%) was introduced at a gas flow rate of 0.15 m 3 / kg / h under stirring at a speed of 100 r / min, the oxidation temperature was 280°C, the oxidation time was 180 min, after the oxidation was completed, the temperature was increased to 360°C and N2 was introduced for condensation, the gas flow rate was 0.2 m 3 / kg / h, the condensation time was 240 min, and the stirring speed was 200 r / min, and the pitch core component was obtained.

[0056] (3) 100 parts of the pitch shell component heated to 190°C and having good fluidity were uniformly sprayed onto the surface of 40 parts of the pitch core component particles which were cold-frozen and crushed to 80-120 mesh, and the pitch composition was obtained.

[0057] (4) 100 g of the low-temperature cold-frozen drilling fluid modified pitch (low-temperature cold-frozen conditions: temperature -32°C, time 10 h) was added to a high-speed pulverizer, and was crushed for 40 s to obtain drilling fluid pitch composition particles A2, and the average particle size was 85 μm.

[0058] Example 3

[0059] (1) 100 parts of Tahe reduced residue (properties are shown in Table 1) heated to a flowable state and 35 parts of Inner Mongolia oil sand pitch (properties are shown in Table 2) were added to a high-pressure reaction kettle at a temperature of 130°C and stirred, 0.4 parts of polyphosphoric acid with a phosphoric acid content (calculated as H3PO4) of 135% was slowly added to the reaction kettle (added within 3 min), and the temperature was programmed to rise to 160°C at a rate of 2°C / min under stirring at a speed of 600 r / min, and the reaction time was 4 h; after the reaction was completed, the reaction kettle was placed in a heat preservation oven, the heat preservation temperature was 120°C, and the heat preservation time was 10 h. After the heat preservation was completed, vacuum deep-cutting was carried out, and vacuum residue greater than 455°C was obtained, i.e. the pitch shell component was obtained.

[0060] (2) 100 parts of ethylene tar heavy component (same as in Example 1) heated to a flowable state, 2 parts of boric acid, 3 parts of p-toluenesulfonic acid, and 5 parts of waste activated carbon adsorbent (25% microporous, 15% mesoporous, and 60% macroporous) soaked in distilled water for 15 h were added to an oxidation kettle, the activated carbon adsorbent was loaded with copper ions and iron ions and had adsorbed a large amount of organic waste gas, oxygen-enriched air (oxygen content was 45%) was introduced into the kettle under stirring at a speed of 100 r / min, the gas flow rate was 0.15 m 3 / kg / h, the oxidation temperature was 260°C, the oxidation time was 180 min, after the oxidation was completed, the temperature was raised to 360°C and N2 was introduced for condensation, the gas flow rate was 0.2 m 3 / kg / h, the condensation time was 240 min, and the stirring speed was 200 r / min, and the pitch core component was obtained.

[0061] (3) 100 parts of the pitch shell component heated to 200°C and having good fluidity were uniformly sprayed onto the surface of 50 parts of the pitch core component particles which were cold-frozen and crushed to 80-120 mesh, and the pitch composition was obtained.

[0062] (4) 100 g of the low-temperature cold-frozen drilling fluid modified pitch (low-temperature cold-frozen conditions: temperature -35°C, time 14 h) was added to a high-speed pulverizer, and was pulverized for 30 s to obtain drilling fluid modified pitch particles A3, and the average particle size was 95 μm.

[0063] Example 4

[0064] (1) 100 parts of Tahe reduced residue (properties are shown in Table 1) heated to a flow state and 50 parts of Inner Mongolia oil sand pitch (properties are shown in Table 2) were added into a high-pressure reaction kettle with a temperature of 130°C and stirred, 0.6 parts of polyphosphoric acid with a content of 135% (calculated as H3PO4) was slowly added into the reaction kettle (added within 3 min), and the temperature was programmed to rise to 160°C at a speed of 2°C / min under a stirring speed of 600 r / min, and the reaction time was 4 h; after the reaction was completed, the reaction kettle was placed for heat preservation, the heat preservation temperature was 120°C, and the heat preservation time was 10 h. After the heat preservation was completed, vacuum deep-cutting was carried out, and vacuum residue with a temperature greater than 455°C was obtained, that is, the pitch shell component was obtained.

[0065] (2) 100 parts of ethylene tar heavy component (same as in Example 1) heated to a flow state, 1 part of p-phenylenediamine, 3 parts of p-toluenesulfonic acid, and 7 parts of waste activated carbon adsorbent (25% microporous, 15% mesoporous, and 60% macroporous) soaked in distilled water for 16 h (the activated carbon adsorbent was loaded with copper ions and iron ions and had adsorbed a large amount of organic waste gas) were added into an oxidation kettle, and oxygen-enriched air (oxygen content was 45%) was introduced at a gas flow rate of 0.15 m 3 / kg / h under a stirring speed of 100 r / min, the oxidation temperature was 290°C, the oxidation time was 200 min, after the oxidation was completed, the temperature was raised to 360°C and N2 was introduced for condensation, the gas flow rate was 0.2 m 3 / kg / h, the condensation time was 240 min, and the stirring speed was 200 r / min, and the pitch core component was obtained.

[0066] (3) 100 parts of the pitch shell component heated to 195°C and having good fluidity were uniformly sprayed onto the surface of 50 parts of the pitch core component particles which were cold-frozen and crushed to 80-120 mesh, and the pitch composition was obtained.

[0067] (4) 100 g of the low-temperature cold-frozen modified pitch (low-temperature cold-frozen conditions: temperature -30°C, time 20 h) was added into a high-speed pulverizer, and was crushed for 30 s to obtain modified pitch particles A4 for drilling fluid, and the average particle size was 85 μm.

[0068] Comparative Example 1

[0069] The same as in Example 1, except that 100 parts of Tahe reduced residue (properties are shown in Table 1) heated to a flow state and 40 parts of Inner Mongolia oil sand pitch (properties are shown in Table 2) in step (1) were changed to 140 parts of Tahe reduced residue (properties are shown in Table 1) heated to a flow state which was added into a high-pressure reaction kettle with a temperature of 130°C and stirred. Finally, the pitch composition particles B1 were obtained.

[0070] Comparative Example 2

[0071] Other than Example 1, except that no pretreatment agent (p-xylylene dimalonate, p-toluene sulfonic acid) was added in step (2). The asphalt composition particles B2 were obtained finally.

[0072] Comparative Example 3

[0073] Other than Example 1, except that no component regulator (waste activated carbon adsorbent) was added in step (2). The asphalt composition particles B3 were obtained finally.

[0074] Comparative Example 4

[0075] Other than Example 1, except that the condensation process was omitted in step (2). The asphalt composition particles B4 were obtained finally.

[0076] Test Example

[0077] The asphalt materials obtained in the examples and comparative examples were tested for softening point and high temperature high pressure filtration loss. The asphalt composition particles obtained in the examples and comparative examples were added into the prepared base slurry, and the amount of the asphalt composition particles added was 2% by weight of the base slurry. The filtration loss after aging (16 h) at different temperatures was measured at a test pressure of 3.45 MPa. The specific results are shown in Table 5. The base slurry was prepared as follows: 2.75 g of anhydrous sodium carbonate was added into 1000 mL of water, and then 60 g of bentonite was added. The mixture was stirred at high speed for 20 minutes and cured at room temperature for 24 hours. Finally, 6% fresh water base slurry was obtained.

[0078] Table 1 Properties of Tahe residue used in the examples and comparative examples

[0079] Carbon residue value / wt% 27.8 Carbon content / wt% 89.13 Nitrogen content / wt% 0.14 Hydrogen content / wt% 7.44 Sulfur content / wt% 3.13 Total content of nickel, vanadium / ug / g 337 Saturates / % 30.17 Aromatics / % 28.11 Gel / % 17.73 Asphaltene / % 23.99 Condensation index CI 0.31 Colloidal instability index Ic 1.18 Penetration at 25°C / 0.1 mm 51 Penetration index (five points) 1.81 Elongation at 25°C / cm 62.4 Softening point / °C 57.8 Flash point / °C 253 Kinematic viscosity (60°C) / Pa.s 1680

[0080] Table 2 Properties of oil sand asphalt used in the examples and comparative examples

[0081]

[0082]

[0083] Table 3 Properties of ethylene tar used in the examples and comparative examples

[0084] Carbon content / wt% 91.9 Nitrogen content / wt% 0.05 Hydrogen content / wt% 6.9 Ash content / wt% 0.18 Total monoaromatics / wt% 14.6 Total diaromatics / wt% 25.1 Total triaromatics / wt% 14.9 Total tetraaromatics / wt% 11.1 Total pentaaromatics / wt% 6.4 Gel / wt% 10.8 Yield at more than 340°C / wt% 68.4

[0085] Table 4 Softening points of asphalt shell and core components obtained in the examples and comparative examples

[0086] Number Shell softening point / °C Core softening point / °C A1 107.8 198.5 A2 90.6 214.1 A3 105.5 207.4 A4 110.2 219.3 B1 76.4 198.6 B2 107.5 186.4 B3 108.1 180.2 B4 107.7 174.9

[0087] Table 5 Properties of asphalt composition obtained in the examples and comparative examples

[0088]

[0089] The scope of protection of the present application is not limited by the foregoing embodiments, but is defined by the claims. Those skilled in the art can make appropriate modifications to the embodiments without departing from the technical idea and the technical scope of the present application, and such modifications are also included in the scope of protection of the present application.

Claims

1. An asphalt composition for drilling fluids, characterized by, The asphalt shell component comprises the following raw material components by weight: inferior residual oil: 100 parts; asphalt core component: 20-60 parts; The asphalt shell component comprises the following raw material components by weight: inferior residual oil: 100 parts; Oil sand asphalt: 20-60 parts; Modifier: 0.1-2 parts; The asphalt core component comprises the following raw material components by weight: heavy component of ethylene tar: 100 parts; Pretreatment agent: 3-12 parts; performance adjusting agent: 0.5-8 parts; The modifier is polyphosphoric acid, and the mass content of phosphoric acid contained in the polyphosphoric acid is 125%-145% as H3PO4; The heavy component of ethylene tar is a heavy component of greater than 340°C obtained by vacuum distillation of ethylene tar; The pretreatment agent is one or more of p-benzene dicarboxaldehyde, p-toluene sulfonic acid, phosphoric acid, boric acid and sulfonic acid; The performance adjusting agent is a waste activated carbon adsorbent; and the waste activated carbon contains copper ions and / or iron ions.

2. The asphalt composition for a drilling fluid according to claim 1, characterized by, The softening point of the asphalt shell is 102-125°C, and the softening point of the asphalt core is 190-230°C.

3. The asphalt composition for a drilling fluid according to claim 1, characterized by, The inferior residual oil has the following properties: flash point of 241°C-256°C, sulfur content of 2.61wt%-3.65wt%, and, as a mass fraction, saturated fraction of 26.1%-37.7%, aromatic fraction of 20.2%-34.5%, resin of 18.3%-24.8%, and asphaltene of 21.3%-30.1%; and / or, The inferior residual oil also has the following properties: carbon residue value of 21wt%-29wt%, nitrogen content of 0.14wt%-0.61wt%, total content of nickel and vanadium of 320-365μg / g, and condensation index CI of 0.26-0.

35.

4. The asphalt composition for a drilling fluid according to claim 1, characterized by, The oil sand asphalt is one or more of Inner Mongolia oil sand asphalt, Qinghai oil sand asphalt, Indonesia oil sand asphalt and Kazakhstan oil sand asphalt.

5. The asphalt composition for a drilling fluid according to claim 4, characterized by The properties of the oil sand bitumen include: softening point not less than 50 DEG C, flash point not less than 232 DEG C, condensation point 25 DEG C~32 DEG C, 100 DEG C viscosity 1450~1600 mm 2 .S -1 Carbon residue 9.5wt%~15.1wt%, sulfur content 2.0wt%~6.1wt%, carbon content 84wt%~87wt%, hydrogen content 10wt%~12.4wt%, nitrogen content 0.2wt%~0.8wt%, in mass fraction, saturated fraction accounts for 10.1%~30.7%, aromatic fraction accounts for 15.6%~35.9%, gum accounts for 30.4%~45.8%, and asphaltene accounts for 10.7%~27.3%.

6. The asphalt composition for a drilling fluid according to claim 5, characterized by The oil sand asphalt has the following properties: softening point of 55°C-65°C, and flash point of 235°C-256°C.

7. The asphalt composition for a drilling fluid according to claim 1, characterized by In the waste activated carbon adsorbent, micropores of less than 2nm account for 20%-40% of the total pore volume, mesopores of 2nm-50nm account for 10%-25% of the total pore volume, and macropores of greater than 50nm account for 35%-70% of the total pore volume.

8. A preparation method of the asphalt composition for drilling fluid according to any one of claims 1-7, comprising: (1) adding inferior residual oil heated to a flow state, oil sand asphalt and modifier to a reaction kettle, stirring and heating to a reaction temperature, and carrying out heat preservation treatment after the reaction is completed; After the heat preservation is completed, vacuum deep drawing is carried out to obtain the asphalt shell component; (2) adding heavy component of ethylene tar heated to a flow state, pretreatment agent and performance adjusting agent to an oxidation kettle to carry out oxidation treatment, and carrying out condensation treatment after the oxidation treatment is completed to obtain the asphalt core component; (3) uniformly spraying the asphalt shell component heated to a flow state on the asphalt core component which is crushed into granules to obtain the asphalt composition for drilling fluid.

9. The method of claim 8, wherein, In step (1), the stirring speed is 600-800 r / min; the heating to the reaction temperature is heating to the reaction temperature by programmed temperature increase, the temperature increase rate is 1-3 ℃ / min, the reaction temperature is 140-180 ℃, and the reaction time is 3-6 h; and / or, The conditions of the heat preservation treatment are heat preservation at 120-135 ℃ for 10-16 h; and / or, The end temperature of the reduced pressure deep drawing is 453-460 ℃.

10. The method of claim 8, wherein, In step (2), when the oxidation treatment is performed, an oxidizing gas is introduced; the oxidizing gas is oxygen-enriched air, the oxygen volume content of the oxygen-enriched air is 30% to 55%, the gas flow rate is 0.06 to 0.4 m 3 / kg / h; the temperature of the oxidation treatment is 220°C to 320°C, the time of the oxidation treatment is 150 to 240 min, and the stirring speed during the oxidation treatment is 50 to 200 r / min.

11. The method of claim 8, wherein, In step (2), the condensation temperature is 320-380℃, the gas used in the condensation process is inert gas and / or N2, the gas flow rate is 0.10-0.25 m3 / kg / h, the condensation reaction time is 200-260 min, and the stirring speed during the condensation process is 100-240 r / min. 3 / kg / h, the condensation reaction time is 200-260 min, and the stirring speed during the condensation process is 100-240 r / min.

12. The method of claim 8, wherein, In step (3), the heating temperature of the pitch shell component is 180-210 ℃.

Images