Compound biological enzyme formula for reducing viscosity of thickened oil

Abstract

The invention relates to the field of petrochemical industry, and discloses a composite biological enzyme formula for reducing viscosity of thickened oil, which comprises the following components by mass: 20-30% of cellulase, 20-30% of cellulase, 10-30% of cellulase, 10-30% of cellulase, 10-30% of cellulase, and 10-30% of water. 15 to 25 percent of pectinase; 10 to 20% of lipase; 10-15% of protease; 5-10% of a stabilizer; 5-10% of a buffer agent; and the balance of deionized water. Cellulase, pectinase, lipase and protease are compounded and prepared according to a specific proportion, synergistic enzymolysis of carbohydrates, lipids and protein impurities in the thickened oil is achieved, the viscosity reduction rate reaches 40%-80%, compared with 50% of single cellulase treatment, higher efficiency is achieved, particularly, in the thickened oil with the initial viscosity of 10000 mPa.s, the viscosity is reduced to 2000 mPa.s after treatment, and the viscosity of the thickened oil with the initial viscosity of 1000 mPa.s is reduced to 300 mPa.s. The applicability of the composite formula under the high-viscosity condition is shown.

Description

Technical Field

[0001] The present invention relates to the field of petrochemical industry, and specifically to a composite bioenzyme formulation for reducing the viscosity of heavy oil. Background Art

[0002] In the prior art, the techniques for reducing the viscosity of heavy oil mainly include physical methods and chemical methods. Physical methods such as steam injection and thermal recovery techniques reduce the viscosity of heavy oil by increasing the temperature, and are applicable to medium and low viscosity heavy oil fields; chemical methods such as using diluents or surfactants improve the fluidity by changing the rheological properties of heavy oil and are widely used in pipeline transportation. In addition, in recent years, bioenzyme technology has gradually developed. A single enzyme such as cellulase is used to decompose high-molecular carbohydrates in heavy oil and is applied to some heavy oil exploitation projects to reduce energy consumption and environmental impact.

[0003] The above methods of the prior art have various limitations. Physical methods such as steam injection have high energy consumption, requiring 15 - 20 kWh per ton of heavy oil processed, are applicable to shallow heavy oil but have limited effect on deep high-viscosity heavy oil; chemical methods may cause environmental pollution due to diluent residues; single enzyme treatment such as cellulase is only applicable to a specific temperature range of 30 - 50 °C and pH 5.5 - 6.5, the viscosity reduction rate is generally 50%, and the treatment efficiency for high-viscosity heavy oil (exceeding 5000 mPa·s) is low, and the storage stability is poor, which limits its popularization and application under complex geological conditions. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the present invention provides a composite bioenzyme formulation for reducing the viscosity of heavy oil, and solves the problems that single enzyme treatment such as cellulase is only applicable to a specific temperature range of 30 - 50 °C and pH 5.5 - 6.5, the viscosity reduction rate is generally 50%, and the treatment efficiency for high-viscosity heavy oil (exceeding 5000 mPa·s) is low.

[0005] To achieve the above object, the present invention is realized through the following technical solutions: A composite bioenzyme formulation for reducing the viscosity of heavy oil, including a composite bioenzyme formulation, and the formulation includes the following components by mass percentage:

[0006] Cellulase 20 - 30%;

[0007] Pectinase 15 - 25%;

[0008] Lipase 10 - 20%;

[0009] Protease 10 - 15%;

[0010] Stabilizer 5 - 10%;

[0011] Buffer 5 - 10%;

[0012] Deionized water for the balance.

[0013] Preferably, the stabilizer is selected from glycerol or polyethylene glycol.

[0014] Preferably, the buffer is citrate buffer salt, which is used to adjust the pH of the formulation to 5.5 - 7.0.

[0015] Preferably, the preparation method of the composite bio - enzyme formulation comprises the following steps:

[0016] S1. Mix cellulase, pectinase, lipase, protease and deionized water according to the mass percentages, and stir evenly;

[0017] S2. Add a buffer to adjust the pH to 5.5 - 7.0;

[0018] S3. Add a stabilizer, stir evenly, and store at 4 - 10 °C for 24 hours;

[0019] S4. Perform ultraviolet or short - time high - temperature sterilization treatment and then subpackage.

[0020] Preferably, the temperature of the short - time high - temperature sterilization treatment in S4 is 80 - 100 °C, and the time is 10 - 15 minutes.

[0021] Preferably, the application method of the composite bio - enzyme formulation comprises the following steps:

[0022] S1. Dilute the formulation in deionized water or low - concentration brine at a volume ratio of 1:100 to 1:500;

[0023] S2. Inject the diluted enzyme solution into the heavy - oil layer or pipeline and mix it with the heavy oil;

[0024] S3. Let it stand or stir gently at 30 - 50 °C for 6 - 12 hours to complete the enzymatic hydrolysis reaction.

[0025] Preferably, the concentration of the low - concentration brine in S1 is 0.5 - 2%.

[0026] Preferably, the application method further comprises detecting the reduction of the viscosity of the heavy oil. If further reduction is required, repeat the injection of the diluted enzyme solution.

[0027] Preferably, the composite bio - enzyme formulation is applied to reduce the viscosity of heavy oil by 50 - 70%, and the applicable temperature range is 5 - 70 °C, and the applicable pH range is 5.5 - 7.5.

[0028] The present invention provides a composite bio - enzyme formulation for reducing the viscosity of heavy oil, which has the following beneficial effects:

[0029] 1. The present invention realizes the synergistic enzymatic hydrolysis of carbohydrates, lipids, and protein impurities in heavy oil by compounding cellulase, pectinase, lipase, and protease in a specific ratio. The viscosity reduction rate reaches 40%-80%, which is more efficient than the 50% achieved by treating with a single cellulase. Especially for heavy oil with an initial viscosity of 10,000 mPa·s, the viscosity is reduced to 2,000 mPa·s after treatment, indicating the applicability of the composite formulation under high-viscosity conditions.

[0030] 2. By adding stabilizers and buffers, the present invention enables the formulation to maintain enzyme activity in the temperature range of 5-70°C and the pH range of 5.5-7.5. Compared with the temperature range of 30-50°C and the pH range of 5.5-6.5 for treating with a single cellulase, the applicable conditions are wider. The enzymatic hydrolysis reaction can still proceed in a low-temperature environment of 5°C or a high-temperature environment of 70°C, indicating the ability of the formulation to adapt to different geological environments.

[0031] 3. The present invention uses biological enzyme viscosity reduction to replace the traditional heating method. The energy consumption is reduced to 10-14 kWh / ton, which is about 10-33% less than the 15 kWh / ton for treating with a single cellulase. The reaction products are biodegradable substances without chemical residues, reducing the environmental burden compared with the residues of single-enzyme treatment.

[0032] 4. By adjusting the enzyme dosage and dilution ratio (1:100 to 1:500), the cost of treating each ton of heavy oil ranges from 150 to 250 yuan. Compared with the 200 yuan for treating with a single cellulase, it has a lower cost under certain conditions. At the same time, it supports adjusting the dosage according to the viscosity of heavy oil, and the operation process is flexible.

[0033] 5. By adding glycerol or polyethylene glycol as a stabilizer, the storage period of the formulation reaches 30 days at 4-10°C. Compared with the short storage time of the single-enzyme formulation, the storage time is extended. And the enzyme activity retention rate is relatively high after sterilization at 80-100°C, supporting repeated use. Description of the Drawings

[0034] Figure 1 It is a flowchart of the preparation method of the composite biological enzyme formulation of the present invention;

[0035] Figure 2 It is a flowchart of the application method of the composite biological enzyme formulation of the present invention. Detailed Embodiments

[0036] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the drawings of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative work shall fall within the protection scope of the present invention.

[0037] Please refer to the attached Figure 1 - Attachment Figure 2 , the embodiment of the present invention provides a composite bio - enzyme formulation for reducing the viscosity of heavy oil, including a composite bio - enzyme formulation. The composite bio - enzyme formulation includes the following components by mass percentage:

[0038] Cellulase 20 - 30%;

[0039] Pectinase 15 - 25%;

[0040] Lipase 10 - 20%;

[0041] Protease 10 - 15%;

[0042] Stabilizer 5 - 10%;

[0043] Buffer 5 - 10%;

[0044] Deionized water for the balance.

[0045] Specifically, through the synergistic effect of cellulase, pectinase, lipase and protease, the formulation enzymatically decomposes high - molecular carbohydrates, lipids, pectin and protein impurities in heavy oil, thereby significantly reducing the viscosity of heavy oil. 20 - 30% of cellulase is mainly responsible for decomposing cellulose - like substances in heavy oil to enhance fluidity; 15 - 25% of pectinase hydrolyzes the pectin structure to reduce the gel characteristics of heavy oil; 10 - 20% of lipase decomposes lipid components to reduce viscosity; 10 - 15% of protease treats protein impurities to avoid pipeline blockage. 5 - 10% of stabilizer such as glycerol or polyethylene glycol is used to maintain enzyme activity and prevent inactivation caused by high temperature or pH changes; 5 - 10% of buffer such as citrate buffer salt adjusts the pH to 5.5 - 7.0 to ensure that the enzyme works in a suitable environment; deionized water is used as a solvent to fill the balance to ensure the uniformity of the formulation. This formulation is particularly suitable for heavy oil with a viscosity in the range of 3000 - 10000 mPa·s, and the viscosity - reducing effect can reach more than 60% in practical applications.

[0046] The stabilizer is selected from glycerol or polyethylene glycol.

[0047] Specifically, the stabilizer is selected from glycerol or polyethylene glycol. Among them, glycerol enhances the stability of the enzyme in low - temperature or high - salt environments through its moisturizing and permeating effects, and is particularly suitable for field storage and transportation conditions; polyethylene glycol forms a protective hydration layer to prevent enzyme molecule denaturation and is suitable for long - term storage or repeated use scenarios. In actual preparation, the dosage of glycerol can be adjusted according to environmental humidity, and the typical dosage is 6 - 8%, while the dosage of polyethylene glycol is 5 - 7%. Both can be used alone or mixed in a 1:1 ratio to optimize cost and effect. In a heavy - oil field environment with large temperature fluctuations, selecting polyethylene glycol can extend the shelf life of the formulation to more than 30 days, which is about 50% longer than the storage period of a single aqueous solution.

[0048] The buffer is a citrate buffer salt, which is used to adjust the pH of the formulation to 5.5 - 7.0.

[0049] Specifically, the buffer is a citrate buffer salt, which is used to adjust the pH of the formulation to 5.5 - 7.0. Specifically, a buffer system is formed by adding citric acid and its sodium salt to ensure the stability of enzyme activity during acid-base changes. The adjustment process within the pH range of 5.5 - 7.0 involves gradually dropping the citrate solution and monitoring it in real-time with a pH meter. The target pH value can be fine-tuned according to the composition of the target heavy oil. For example, pH 6.0 is suitable for heavy oil containing high protein, and pH 5.5 is suitable for heavy oil containing high pectin. The buffer system capacity is usually designed to resist the pH shift of 0.1 mol / L hydrochloric acid or sodium hydroxide and maintain the pH stability within 4 - 6 hours of the enzymatic hydrolysis reaction, significantly improving the enzyme efficiency, especially in the underground environment with drastic pH fluctuations.

[0050] Please refer to the attachment Figure 1 , and the preparation method of the composite bio-enzyme formulation includes the following steps:

[0051] S1. Mix cellulase, pectinase, lipase, protease and deionized water by mass percentage and stir evenly;

[0052] S2. Add a buffer to adjust the pH to 5.5 - 7.0;

[0053] S3. Add a stabilizer, stir evenly and store at 4 - 10 °C for 24 hours;

[0054] S4. Perform ultraviolet or short-term high-temperature sterilization treatment and then subpackage.

[0055] Specifically, the preparation method of the formulation achieves efficient mixing and stability through the following steps: In S1, cellulase, pectinase, lipase, protease and deionized water are added to the stirring tank in proportion, and the stirring speed is controlled at 100 - 150 rpm for 30 - 40 minutes until the mixture becomes a homogeneous emulsion; in S2, the citrate buffer salt is slowly added in the form of a 10% aqueous solution, and the pH is monitored with a pH meter while adding, and the time required to adjust to 5.5 - 7.0 is about 15 - 20 minutes; in S3, stabilizers such as glycerol or polyethylene glycol are added under constant temperature conditions, the stirring speed is reduced to 50 - 70 rpm, and it needs to be placed in a sealed container during storage to avoid oxidation; in S4, ultraviolet sterilization uses a light source with a wavelength of 254 nm for 20 - 30 minutes, or high-temperature sterilization uses a 90 °C water bath for 10 minutes and then is immediately cooled to room temperature and subpackaged into sterile containers. The temperature, pH and stirring time need to be recorded for each step to ensure batch consistency, and the preparation cycle is usually 24 - 48 hours.

[0056] The temperature for high-temperature short-time sterilization treatment in S4 is 80 - 100°C, and the time is 10 - 15 minutes.

[0057] Specifically, the temperature for high-temperature short-time sterilization treatment in S4 is 80 - 100°C, and the time is 10 - 15 minutes. In actual operation, 80°C is applicable to enzyme activity-sensitive formulations, and the treatment time is controlled within 15 minutes to avoid excessive heat denaturation; 100°C is applicable to heat-resistant formulations, and the treatment time is shortened to 10 minutes, which can effectively kill bacterial spores. During the sterilization process, a stainless steel reaction kettle is used, equipped with a temperature sensor and an automatic power-off device to ensure uniform temperature, with the error controlled within ±1°C. Immediately after sterilization, it is cooled to below 40°C through cold water circulation to prevent secondary loss of enzyme activity, and the cooling time is about 20 - 30 minutes. This step is particularly applicable to the heavy oil field site without ultraviolet equipment in the wild, and the sterilization rate can reach over 99.9%.

[0058] Please refer to the appendix Figure 2 , and the application method of the composite bio-enzyme formulation includes the following steps:

[0059] S1. Dilute the formulation in deionized water or low-concentration salt water at a volume ratio of 1:100 to 1:500;

[0060] S2. Inject the diluted enzyme solution into the heavy oil layer or pipeline and mix it with the heavy oil;

[0061] S3. Let it stand or stir slightly for 6 - 12 hours at 30 - 50°C to complete the enzymatic hydrolysis reaction.

[0062] Specifically, the application method of the formulation achieves efficient viscosity reduction through the following steps: In S1, the formulation is diluted at a volume ratio of 1:100 to 1:500. 1:100 is applicable to high-viscosity heavy oil, and 1:500 is applicable to medium-low viscosity heavy oil. The diluted solution is placed in a pressure tank and stirred for 5 - 10 minutes to ensure uniformity; in S2, the diluted enzyme solution is injected into the heavy oil layer through a water injection pump at a flow rate of 0.5 - 1 L / min, or evenly distributed through a pipeline injector, with the contact area with the heavy oil reaching over 90%; in S3, the reaction temperature of 30 - 50°C is controlled by geothermal energy or an auxiliary heater, the stirring speed is set at 20 - 30 rpm, and the enzymatic hydrolysis reaction is gradually completed within 6 - 12 hours to generate low-molecular-weight alcohols and organic acids, promoting the flow of heavy oil. In actual application, the reaction time can be extended to 24 hours according to the viscosity monitoring results to adapt to ultra-heavy oil conditions.

[0063] The concentration of the low-concentration salt water in S1 is 0.5 - 2%.

[0064] Specifically, the concentration of the low-concentration brine in S1 is 0.5-2%. During specific preparation, a 0.5% concentration is applicable to heavy oil with high minerals, and a 2% concentration is applicable to heavy oil with high chlorides. The brine is prepared by adding sodium chloride or potassium chloride to distilled water, stirring and dissolving it, and then filtering until there are no suspended substances. The selection of the brine concentration needs to consider the tolerance of the enzyme to ionic strength. Within the range of 0.5-2%, the loss of enzyme activity is less than 5%. When it is higher than 2%, the enzymatic hydrolysis efficiency decreases by about 20%. In heavy oil fields with high salt content, diluting with 1.5% brine can balance the osmotic pressure and enhance the penetration depth of the enzyme solution. The typical penetration distance reaches 5-10 meters.

[0065] The application method also includes detecting the reduction of heavy oil viscosity. If further reduction is needed, the diluted enzyme solution is injected repeatedly.

[0066] Specifically, the application method also includes detecting the reduction of heavy oil viscosity. If further reduction is needed, the diluted enzyme solution is injected repeatedly. The detection process uses a rotational viscometer, the measurement temperature is 40°C, the shear rate is 10 s^-1, the initial viscosity and the viscosity after the reaction are recorded. Injection can be stopped when the viscosity reduction rate reaches 50%. When it is lower than 50%, the diluted enzyme solution is injected repeatedly. The single injection volume is 1 / 2 to 1 / 3 of the previous time, and the interval is 4-6 hours. The repeated injection does not exceed 3 times at most to ensure economy. After the third injection, the viscosity reduction rate usually stabilizes at 65-70%. This step is particularly suitable for heavy oil layers with large viscosity fluctuations. The monitoring data can be uploaded in real time through an automated system for convenient on-site management.

[0067] The application of the composite bio-enzyme formula to heavy oil results in a viscosity reduction rate of 50-70%. The applicable temperature range is 5-70°C, and the applicable pH range is 5.5-7.5.

[0068] Specifically, the application of the formula to heavy oil results in a viscosity reduction rate of 50-70%. The applicable temperature range is 5-70°C, and the applicable pH range is 5.5-7.5. The viscosity reduction rate test uses a simulated well condition device. Heavy oil with an initial viscosity of 5000 mPa·s is reduced to 1500 mPa·s after 8 hours of treatment, and the viscosity reduction rate is 70%. When the temperature is 5°C, the reaction rate slows down and it needs to be extended to 12 hours. When the temperature is 70°C, the reaction rate speeds up and the viscosity reduction can reach 60% within 6 hours. Within the pH range of 5.5-7.5, the enzyme activity is the highest. When the pH is lower than 5.0 or higher than 8.0, the activity decreases by about 30%. Therefore, the formula is particularly suitable for neutral to weakly acidic heavy oil environments. In actual field tests, the temperature gradient of 5-70°C covers most of the heavy oil field conditions, and the application effect is stable. The annual oil production increase rate per well can be increased by 10-15%.

[0069] The following is an introduction in combination with specific embodiments:

[0070] Example 1: The lowest data example

[0071] Formulation composition

[0072] Cellulase 20%;

[0073] Pectinase 15%;

[0074] Lipase 10%;

[0075] Protease 10%;

[0076] Stabilizer 5% (glycerol);

[0077] Buffer 5% (citrate buffer salt);

[0078] Deionized water 45%.

[0079] Preparation process

[0080] S1 Place cellulase, pectinase, lipase, protease in the above proportions and deionized water in a stirring tank, stir at a speed of 100 rpm for 30 minutes to obtain a homogeneous mixture;

[0081] S2 Add citrate buffer saline solution and adjust the pH to 5.5, which takes 15 minutes;

[0082] S3 Add glycerol, stir at a speed of 50 rpm and store at 4°C for 24 hours;

[0083] S4 Sterilize in an 80°C water bath for 10 minutes, and after cooling to room temperature, dispense.

[0084] Application method

[0085] S1 Dilute the formula in 0.5% sodium chloride solution at a volume ratio of 1:500 and stir for 5 minutes;

[0086] S2 Inject into a heavy oil sample with an initial viscosity of 3000 mPa·s through a water injection pump at a flow rate of 0.5 L / min;

[0087] S3 Let it stand at 30°C for 6 hours.

[0088] Test results

[0089] Initial viscosity 3000 mPa·s, viscosity after treatment 1200 mPa·s, viscosity reduction rate 40%, applicable temperature 5°C, pH 5.5, treatment time 6 hours.

[0090] Description

[0091] This example uses the lowest formula ratio and application conditions, is applicable to low-viscosity heavy oil, has a relatively low viscosity reduction rate but can meet the basic flow requirements, and is especially suitable for on-site with limited resources.

[0092] Example 2: Intermediate value example

[0093] Formulation composition

[0094] Cellulase 25%;

[0095] Pectinase 20%;

[0096] Lipase 15%;

[0097] Protease 12%;

[0098] Stabilizer 7% (polyethylene glycol);

[0099] Buffer 6% (citrate buffer salt);

[0100] Deionized water 35%.

[0101] Preparation process

[0102] S1 Mix the enzyme components in the above proportions with deionized water at a stirring speed of 120 rpm for 35 minutes;

[0103] S2 Add the citrate buffer saline solution and adjust the pH to 6.0, which takes 18 minutes;

[0104] S3 Add polyethylene glycol, stir at a speed of 60 rpm, and store at 8°C for 24 hours;

[0105] S4 Sterilize in a 90°C water bath for 12 minutes, and then aliquot after cooling to room temperature.

[0106] Application method

[0107] S1 Dilute the formula in a 1% sodium chloride solution at a volume ratio of 1:300 and stir for 8 minutes;

[0108] S2 Inject into a heavy oil sample with an initial viscosity of 5000 mPa·s through a pipeline injector at a flow rate of 0.8 L / min;

[0109] S3 Stir gently at 20 rpm at 40°C for 8 hours.

[0110] Test results

[0111] Initial viscosity 5000 mPa·s, viscosity after treatment 1500 mPa·s, viscosity reduction rate 70%, applicable temperature 40°C, pH 6.0, treatment time 8 hours.

[0112] Description

[0113] This example adopts the median formula and conditions, is applicable to medium-viscosity heavy oil, has a relatively high viscosity reduction rate, takes into account both efficiency and cost, and is applicable to most heavy oil field conditions.

[0114] Example 3: Example with the highest data

[0115] Formulation composition

[0116] Cellulase 30%;

[0117] Pectinase 25%;

[0118] Lipase 20%;

[0119] Protease 15%;

[0120] Stabilizer 10% (glycerol and polyethylene glycol mixed in a ratio of 1:1);

[0121] Buffer 10% (citrate buffer salt);

[0122] Deionized water 20%.

[0123] Preparation process

[0124] S1 Mix the enzyme components in the above proportions with deionized water at a stirring speed of 150 rpm for 40 minutes;

[0125] S2 Add citrate buffer saline solution and adjust the pH to 7.0, which takes 20 minutes;

[0126] S3 Add the mixed stabilizer of glycerol and polyethylene glycol, stir at a speed of 70 rpm, and store at 10 °C for 24 hours;

[0127] S4 Sterilize in a 100 °C water bath for 15 minutes and then aliquot after cooling to room temperature.

[0128] Application method

[0129] S1 Dilute the formula in a 2% sodium chloride solution at a volume ratio of 1:100 and stir for 10 minutes;

[0130] S2 Inject into a heavy oil sample with an initial viscosity of 10000 mPa·s at a flow rate of 1 L / min through a water injection pump;

[0131] S3 Stir gently at 30 rpm at 50 °C for 12 hours.

[0132] Test results

[0133] Initial viscosity 10000 mPa·s, viscosity after treatment 2000 mPa·s, viscosity reduction rate 80%, applicable temperature 70 °C, pH 7.5, treatment time 12 hours.

[0134] Description

[0135] This example uses the highest formula ratio and application conditions, is applicable to high-viscosity ultra-heavy oil, has the highest viscosity reduction rate, is particularly suitable for the exploitation of deep heavy oil under complex geological conditions, and has remarkable effects but relatively high costs.

[0136] Table 1: Comparison of Different Embodiments with Single Cellulase

[0137]

[0138] Explanation of Table Characters:

[0139] Initial Viscosity of Heavy Oil (mPa·s)

[0140] Description: Represents the viscosity of heavy oil before treatment, with the unit of millipascal-second (mPa·s).

[0141] Meaning: Viscosity measures the fluidity of heavy oil. The higher the initial value, the greater the treatment difficulty.

[0142] Example: In the prior art, it is 5000 mPa·s, and in Embodiments 1-3, it is 3000-10000 mPa·s, covering a wider range.

[0143] Viscosity after Treatment (mPa·s)

[0144] Description: Represents the viscosity of heavy oil after treatment, with the unit of millipascal-second (mPa·s).

[0145] Meaning: Reflects the viscosity reduction effect. The lower the value, the better the fluidity.

[0146] Example: In the prior art, it is 2500 mPa·s, and in Embodiments 1-3, it is 1200-2000 mPa·s, with better effects.

[0147] Viscosity Reduction Rate (%)

[0148] Description: Represents the proportion of viscosity reduction, with the unit of percentage (%).

[0149] Meaning: Viscosity reduction rate = (initial viscosity - viscosity after treatment) / initial viscosity × 100%, measuring the technical efficiency.

[0150] Example: In the prior art, it is 50%, and in Embodiments 1-3, it is 40-80%, with stronger performance of the present invention.

[0151] Applicable Temperature Range (°C)

[0152] Description: Represents the temperature range applicable to the formulation, with the unit of degree Celsius (°C).

[0153] Meaning: Reflects the applicability of the technology at different ambient temperatures. The wider the range, the stronger the adaptability.

[0154] Example: In the prior art, it is 30-50 °C, and in Embodiments 1-3, it is 5-70 °C, covering more scenarios.

[0155] Applicable pH Range

[0156] Description: Represents the pH value range applicable to the formulation, without a unit.

[0157] Meaning: The pH range affects the enzyme stability. A wider range indicates a stronger ability to adapt to acid-base changes.

[0158] Example: The prior art is 5.5 - 6.5, and Examples 1 - 3 are 5.5 - 7.5, with a wider adaptability.

[0159] Energy consumption (kWh / ton)

[0160] Description: It represents the energy required to process each ton of viscous oil, with the unit of kilowatt-hour per ton (kWh / ton).

[0161] Meaning: It measures the energy consumption level of the process. The lower the value, the more energy-efficient.

[0162] Example: The prior art is 15 kWh / ton, and Examples 1 - 3 are 10 - 14 kWh / ton, with a significant energy-saving effect.

[0163] Environmental impact

[0164] Description: Qualitatively describes the impact on the environment, using words such as "low" and "medium".

[0165] Meaning: It reflects whether the process produces harmful residues or pollution, embodying environmental friendliness.

[0166] Example: The prior art is medium (including chemical residues), and Examples 1 - 3 are low (naturally degradable), which is more environmentally friendly.

[0167] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A composite bioenzyme formulation for reducing the viscosity of heavy oil, including the composite bioenzyme formulation, characterized in that, The composite bio-enzyme formulation comprises the following components by mass percentage: Cellulase 20 - 30%; Pectinase 15 - 25%; Lipase 10 - 20%; Protease 10 - 15%; Stabilizer 5 - 10%; Buffer 5 - 10%; Deionized water for the balance.

2. The compound bio-enzyme formulation for reducing the viscosity of heavy oil according to claim 1, wherein, The stabilizer is selected from glycerol or polyethylene glycol.

3. The composite bio - enzyme formulation for reducing the viscosity of heavy oil according to claim 1, wherein, The buffer is a citrate buffer salt, which is used to adjust the pH of the formulation to 5.5 - 7.

0.

4. The composite bio - enzyme formulation for reducing the viscosity of heavy oil according to claim 1, wherein, The preparation method of the composite bio-enzyme formulation comprises the following steps: S1. Mix cellulase, pectinase, lipase, protease and deionized water according to the said mass percentage, and stir evenly; S2. Add the buffer to adjust the pH to 5.5 - 7.0; S3. Add the stabilizer, stir evenly and store at 4 - 10°C for 24 hours; S4. Carry out ultraviolet or high-temperature short-time sterilization treatment and then subpackage.

5. The composite bio-enzyme formulation for reducing the viscosity of heavy oil according to claim 4, characterized in that, In the said S4, the temperature of the high-temperature short-time sterilization treatment is 80 - 100°C and the time is 10 - 15 minutes.

6. The composite bio - enzyme formulation for reducing the viscosity of heavy oil according to claim 1, characterized in that, The application method of the composite bio-enzyme formulation comprises the following steps: S1. Dilute the formulation in deionized water or low-concentration brine at a volume ratio of 1:100 to 1:500; S2. Inject the diluted enzyme solution into the heavy oil layer or pipeline and mix it with the heavy oil; S3. Let it stand or stir slightly at 30 - 50°C for 6 - 12 hours to complete the enzymatic hydrolysis reaction.

7. The composite bio - enzyme formulation for reducing the viscosity of heavy oil according to claim 6, wherein, In the said S1, the concentration of the low-concentration brine is 0.5 - 2%.

8. The composite bio - enzyme formulation for reducing the viscosity of heavy oil according to claim 6, wherein, The application method further comprises detecting the reduction of the heavy oil viscosity. If further reduction is needed, repeat injecting the diluted enzyme solution.

9. The composite bio - enzyme formulation for reducing the viscosity of heavy oil according to claim 6, wherein, The composite bio-enzyme formulation is applied to reduce the heavy oil viscosity by 50 - 70%, and the applicable temperature range is 5 - 70°C, and the applicable pH range is 5.5 - 7.5.

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