Resourceful treatment method for regeneration of oil-based drilling fluid

Abstract

The invention provides a regeneration and resourceful treatment method for oil-based drilling fluid. The method comprises the following steps: uniformly mixing the oil-based drilling fluid to be treated with a demulsifier and / or a catalyst to obtain a mixture; wherein the demulsifying agent comprises at least one of an ionic demulsifying agent and an organic non-ionic demulsifying agent, and the catalyst comprises at least one of salt-forming alkaline oxide, metal hydroxide and mixed metal salt; and carrying out thermal distillation on the mixture, and separating and recovering oil components. According to the technical scheme provided by the invention, the oil-based drilling fluid is treated in a demulsification / catalysis and thermal distillation synergistic manner, and the demulsification / catalysis and distillation technologies are synergistic, so that the demulsifier and / or the catalyst can fully play a role in reducing the interface stability of the oil-based drilling fluid, and the oil component can be separated out more easily in the distillation process. And the demulsifier and the catalyst do not influence the properties of the recovered oil. Therefore, the oil-based drilling fluid is regenerated and recycled with low energy consumption, high treatment efficiency and no influence on the property of the recycled oil.

Description

Technical Field

[0001] The present invention belongs to the field of oil and gas, especially the technical field of drilling waste treatment, and particularly relates to a method for recycling and resource treatment of oil-based drilling fluid. Background Art

[0002] Due to its strong inhibition, high temperature resistance, excellent lubricity and other characteristics, oil-based drilling fluid has become the preferred drilling fluid for deep wells, high temperature wells, extended reach wells, etc. In order to save drilling costs, oil-based drilling fluid is recycled and used multiple times while drilling. However, with the continuous intrusion of harmful solids such as formation soil, a large amount of oil and various hydrocarbons and other chemical substances in the drilling fluid are adsorbed by the harmful solids, resulting in an increase in the viscosity and shear force of the recovered oil-based drilling fluid system, a continuous increase in the content of low-density solids, and a gradual deterioration of the inherent properties, generating waste oil-based drilling fluid. Diluting the oil-based drilling fluid with fresh white oil in proportion temporarily solves the problem of recycling, but leads to a large volume of oil-based drilling fluid, difficult performance maintenance, increased storage costs, and increased treatment costs. The harmless treatment and recycling of oil-based drilling fluid after multiple cycles of use has become an urgent issue in the environmental protection and energy consumption reduction work of the drilling industry.

[0003] Currently, the treatment technologies for the recycling and resource treatment of oil-based drilling fluid mainly include solvent extraction method, thermal distillation method, supercritical fluid extraction method, etc. Among them, the thermal distillation method is widely used for the treatment of oil-based drilling fluid. The thermal distillation method heats the oil-based drilling fluid in a closed system, causing the liquid-phase components in the drilling fluid to volatilize at a higher temperature and be recovered after condensation. The recovered oil can be used for formulating oil-based drilling fluid. However, the thermal distillation method currently has problems such as high energy consumption, high cost, and low safety. Therefore, it is urgent to optimize the thermal distillation method for oil-based drilling fluid treatment technology to improve quality and efficiency, achieve energy conservation and consumption reduction or increase the treatment volume, separate, recover and purify the base oil in the drilling fluid at a lower energy consumption to meet the requirements for reuse in formulating drilling fluid, and realize the efficient recycling and utilization of oil-based drilling fluid. Summary of the Invention

[0004] Aiming at the problems of oil-based drilling fluid after multiple cycles of use (an oil-in-water type multiphase colloid mixture composed of oil, water, organic solid particles such as asphaltene, inorganic solid particles such as drill cuttings, high molecular compounds and other chemical substances), such as high emulsification degree, high viscosity, difficult resource recovery, high energy consumption, etc., the purpose of the present invention is to provide a recycling and resource treatment technology for oil-based drilling fluid with low energy consumption and without affecting the properties of the recovered oil.

[0005] To achieve the above purpose, the present invention provides a method for recycling and resource treatment of oil-based drilling fluid, wherein the method includes:

[0006] Mix the oil-based drilling fluid to be treated with a demulsifier and / or a catalyst to obtain a mixture; wherein, the demulsifier includes at least one of an ionic demulsifier and an organic non-ionic demulsifier, and the catalyst includes at least one of a salt-forming basic oxide, a metal hydroxide, and a mixed metal salt;

[0007] Perform thermal distillation on the mixture to separate and recover the oily components.

[0008] The technical solution provided by the present invention uses a demulsifier and / or a catalyst in combination with thermal distillation for treating the oil-based drilling fluid. The combination of the demulsifier and / or the catalyst with thermal distillation is more conducive to breaking the multiphase colloid stability system of the oil-based drilling fluid and changing its micro-interface properties; it can efficiently play the role of demulsification or catalysis, improve the utilization rate of the demulsifier and / or the catalyst; it can better achieve the desorption and separation of the oil phase and the solid phase, improve the separation efficiency of the base oil from the drilling fluid, and effectively recover the oil phase components. In short, the technical solution provided by the present invention performs thermal distillation under the condition of adding a demulsifier and / or a catalyst. During the thermal distillation process, the demulsifier and / or the catalyst can effectively reduce the oil-water interfacial tension, overcome the cohesive work between oil droplets, reduce the adhesion force between the solid and liquid phases, or reduce the desorption activation energy, making the oily components easier to be distilled out, thereby separating the base oil in the drilling fluid with low energy consumption. In addition, the demulsifier and the catalyst will not affect the properties of the recovered oil and avoid secondary pollution. Thus, the oil-based drilling fluid treatment is achieved with low energy consumption and without affecting the properties of the recovered oil.

[0009] In the above oil-based drilling fluid regeneration and resource utilization treatment method, preferably, based on the mass of the oil-based drilling fluid to be treated being 100%, the total amount of the demulsifier and the catalyst is 0.5-5%;

[0010] Preferably, based on the mass of the oil-based drilling fluid to be treated being 100%, the total amount of the demulsifier and the catalyst is 1-3%.

[0011] In the above oil-based drilling fluid regeneration and resource utilization treatment method, preferably, mix the oil-based drilling fluid to be treated with a demulsifier and a catalyst to obtain a mixture;

[0012] Further, based on the mass of the oil-based drilling fluid to be treated being 100%, the mass of the demulsifier is 0.5-4.5 wt%; furthermore, based on the mass of the oil-based drilling fluid to be treated being 100%, the mass of the demulsifier is 0.8-2.2%;

[0013] Further, based on the mass of the oil-based drilling fluid to be treated being 100%, the mass of the catalyst is 0.5-4.5 wt%; furthermore, based on the mass of the oil-based drilling fluid to be treated being 100%, the mass of the catalyst is 0.8-2.2%.

[0014] In the above oil-based drilling fluid regeneration and resource treatment method, preferably, the demulsifier can be prepared by a preparation method including the following steps: using at least one of organic amine, fatty alcohol, polyol and resin as an initiator, and carrying out block polymerization with at least one of ethylene oxide and propylene oxide to obtain the organic non-ionic demulsifier;

[0015] Furthermore, the preparation method further includes: modifying the product obtained by block polymerization by methods such as head modification, tail replacement, backbone addition, crosslinking, compounding and molecular weight increase;

[0016] Furthermore, the preparation method further includes: adding synergistic agents such as flocculants, defoamers and catalysts.

[0017] In the above oil-based drilling fluid regeneration and resource treatment method, preferably, the demulsifier includes at least one of sodium dodecyl sulfonate, sodium dodecyl benzene sulfonate, Tween 20, BASF-L64, Thg-9603, NP-9, etc.

[0018] In the above oil-based drilling fluid regeneration and resource treatment method, preferably, the salt-forming basic oxides include at least one of calcium oxide and iron oxide.

[0019] In the above oil-based drilling fluid regeneration and resource treatment method, preferably, the metal hydroxides include at least one of potassium hydroxide and sodium hydroxide.

[0020] In the above oil-based drilling fluid regeneration and resource treatment method, preferably, the metal salts include at least one of calcium chloride, ferric chloride, ferrous chloride and inorganic polyferric salts.

[0021] In the above oil-based drilling fluid regeneration and resource treatment method, preferably, the heating methods for thermal distillation include but are not limited to at least one of forms such as electromagnetic heating, microwave heating and fuel combustion heating.

[0022] In the above oil-based drilling fluid regeneration and resource treatment method, preferably, the temperature of the thermal distillation is 300 - 350 °C.

[0023] In the above oil-based drilling fluid regeneration and resource treatment method, preferably, the pressure of the thermal distillation is 0 - 0.09 MPa.

[0024] In the above oil-based drilling fluid regeneration and resource treatment method, preferably, the time of the thermal distillation is 0.1 - 0.6 h.

[0025] The technical solution provided by the present invention uses the synergistic method of demulsification / catalysis and thermal distillation for the treatment and resource utilization of oil-based drilling fluids, which is a green and low-consumption method for the treatment of oil-based drilling fluids by the synergistic action of chemical agents and distillation. The synergy between demulsification / catalysis and distillation technology enables the demulsifier and / or catalyst to more fully play the role of reducing the interfacial stability of oil-based drilling fluids, making it easier for the base oil fraction to be separated during the distillation process, thereby achieving the purpose of resource utilization and harmless disposal of oil-based drilling fluids, with green environmental protection, energy conservation and consumption reduction. Compared with the prior art, the technical solution provided by the present invention has the following advantages and beneficial effects:

[0026] 1. The technical solution provided by the present invention can improve the separation efficiency of base oil from drilling fluids and effectively reduce energy consumption compared with the technology of simply treating oil-based drilling fluids by thermal distillation.

[0027] 2. The technical solution provided by the present invention will not affect the properties of the recovered oil and avoid secondary pollution compared with the technology of simply treating oil-based drilling fluids by thermal distillation.

[0028] 3. The technical solution provided by the present invention has the advantages of simple process, convenient operation, scientific principle, high energy utilization rate, reduced pollution and environmental friendliness. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic flow chart of the method for the regeneration and resource utilization of oil-based drilling fluids in the embodiments of the present invention.

[0030] Figure 2 It is a comparison chart of energy consumption corresponding to parameters such as thermal distillation temperature, thermal distillation time, and power consumption recorded by an intelligent electricity meter in Embodiments 1-9 and Comparative Example 1 of the present invention.

[0031] Figure 3 It is a comparison chart of energy consumption corresponding to parameters such as thermal distillation temperature, thermal distillation time, and power consumption recorded by an intelligent electricity meter in Embodiments 10-18 and Comparative Example 2 of the present invention.

[0032] Figure 4 It is a comparison chart of liquid phase recovery rate and remaining solid oil content in Embodiments 1-9 and Comparative Example 1 of the present invention.

[0033] Figure 5 It is a comparison chart of liquid phase recovery rate and remaining solid oil content in Embodiments 10-18 and Comparative Example 2 of the present invention.

[0034] Figure 6 It is a comparison chart of energy consumption corresponding to parameters such as thermal distillation temperature, thermal distillation time, and power consumption recorded by an intelligent electricity meter in Embodiments 19-24 of the present invention.

[0035] Figure 7 It is a comparison chart of liquid phase recovery rate and remaining solid oil content in Embodiments 19-24 of the present invention.

[0036] Figure 8 This is the GC-MS comparison chart of the recycled oil in Example 1 and 4 and Comparative Example 1 of the present invention.

[0037] Figure 9 This is the SEM and EDX analysis comparison chart of the remaining solids in Example 9 and Comparative Example 1. Detailed implementation manners

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments 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. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0039] Example 1

[0040] This example provides a method for the regenerative resource treatment of oil-based drilling fluids. The process is as Figure 1 shown, and the method includes:

[0041] Add the demulsifier BASF-L64 to 100 mL of the oil-based drilling fluid to be treated and mix them on a magnetic stirrer for 15 minutes until they are fully mixed to obtain a mixture. Based on the mass of the oil-based drilling fluid to be treated being 100%, the dosage of BASF-L64 is 1.0 wt%.

[0042] Put the mixture into a thermal distillation device at -0.07 MPa for thermal distillation to obtain distillation gas and remaining solid residues. Condense and recover the liquid phase of the distillation gas, separate the oil and water of the liquid phase product to obtain recycled base oil, and discharge the remaining solid residues after treatment to meet the standards. Record the thermal distillation temperature, thermal distillation time, and the power consumption recorded by the intelligent electricity meter. The results are as Figure 2 shown.

[0043] Analyze and determine the liquid phase recovery rate, and analyze and determine the oil content rate of the remaining solid residues. The results are as Figure 4 shown.

[0044] Example 2

[0045] This example provides a method for the regenerative resource treatment of oil-based drilling fluids. The difference between this method and that of Example 1 is that the demulsifier used is Thg-9603 instead of the demulsifier BASF-L64.

[0046] The results of the thermal distillation temperature, thermal distillation time, and the power consumption recorded by the intelligent electricity meter are as Figure 2 shown.

[0047] The results of the liquid-phase recovery rate and the oil content rate of the remaining solid in the remaining solid residue are as Figure 4 shown below.

[0048] Example 3

[0049] This example provides a method for the regeneration and resource treatment of oil-based drilling fluid. Among them, the difference between this method and Example 1 is only that the demulsifier used is NP-9 instead of BASF-L64.

[0050] The results of the thermal distillation temperature, thermal distillation time, and the power consumption recorded by the smart electricity meter are as Figure 2 shown below.

[0051] The results of the liquid-phase recovery rate and the oil content rate of the remaining solid in the remaining solid residue are as Figure 4 shown below.

[0052] Example 4

[0053] This example provides a method for the regeneration and resource treatment of oil-based drilling fluid. Among them, the difference between this method and Example 1 is only that the catalyst used is KOH instead of BASF-L64.

[0054] The results of the thermal distillation temperature, thermal distillation time, and the power consumption recorded by the smart electricity meter are as Figure 2 shown below.

[0055] The results of the liquid-phase recovery rate and the oil content rate of the remaining solid in the remaining solid residue are as Figure 4 shown below.

[0056] Example 5

[0057] This example provides a method for the regeneration and resource treatment of oil-based drilling fluid. Among them, the difference between this method and Example 1 is only that the catalyst used is NaOH instead of BASF-L64.

[0058] The results of the thermal distillation temperature, thermal distillation time, and the power consumption recorded by the smart electricity meter are as Figure 2 shown below.

[0059] The results of the liquid-phase recovery rate and the oil content rate of the remaining solid in the remaining solid residue are as Figure 4 shown below.

[0060] Example 6

[0061] This example provides a method for the regeneration and resource treatment of oil-based drilling fluid. Among them, the difference between this method and Example 1 is only that the catalyst used is CaCl 2 instead of BASF-L64.

[0062] The results of the thermal distillation temperature, thermal distillation time, and the power consumption recorded by the smart electricity meter are asFigure 2 as shown

[0063] The results of the liquid-phase recovery rate and the oil content rate of the remaining solid in the remaining solid residue are as Figure 4 shown

[0064] Example 7

[0065] This example provides a method for the regenerative resource treatment of oil-based drilling fluid. The difference between this method and that of Example 1 is only that the catalyst used is FeCl 3 ·6H 2 O instead of the demulsifier BASF-L64

[0066] The results of the thermal distillation temperature, the thermal distillation time, and the power consumption recorded by the smart electric meter are as Figure 2 shown

[0067] The results of the liquid-phase recovery rate and the oil content rate of the remaining solid in the remaining solid residue are as Figure 4 shown

[0068] Example 8

[0069] This example provides a method for the regenerative resource treatment of oil-based drilling fluid. The difference between this method and that of Example 1 is only that the catalyst used is CaO instead of the demulsifier BASF-L64

[0070] The results of the thermal distillation temperature, the thermal distillation time, and the power consumption recorded by the smart electric meter are as Figure 2 shown

[0071] The results of the liquid-phase recovery rate and the oil content rate of the remaining solid in the remaining solid residue are as Figure 4 shown

[0072] Example 9

[0073] This example provides a method for the regenerative resource treatment of oil-based drilling fluid. The difference between this method and that of Example 1 is only that the catalyst used is Fe 2 O 3 instead of the demulsifier BASF-L64

[0074] The results of the thermal distillation temperature, the thermal distillation time, and the power consumption recorded by the smart electric meter are as Figure 2 shown

[0075] The results of the liquid-phase recovery rate and the oil content rate of the remaining solid in the remaining solid residue are as Figure 4 shown

[0076] Example 10

[0077] This embodiment provides a method for the regenerative resource treatment of oil-based drilling fluid. The difference between this method and that of Embodiment 1 is only that: the dosage of demulsifier BASF-L64 is 3.0 wt% instead of 1.0 wt%, the stirring time of the magnetic stirrer is 30 min instead of 15 min, and the pressure of the thermal distillation device is -0.09 MPa instead of -0.07 MPa.

[0078] The results of the thermal distillation temperature, thermal distillation time, and power consumption recorded by the smart electricity meter are as Figure 3 shown.

[0079] The results of the liquid phase recovery rate and the oil content rate of the remaining solid residue are as Figure 5 shown.

[0080] Embodiment 11

[0081] This embodiment provides a method for the regenerative resource treatment of oil-based drilling fluid. The difference between this method and that of Embodiment 10 is only that the demulsifier used is Thg-9603 instead of demulsifier BASF-L64.

[0082] The results of the thermal distillation temperature, thermal distillation time, and power consumption recorded by the smart electricity meter are as Figure 3 shown.

[0083] The results of the liquid phase recovery rate and the oil content rate of the remaining solid residue are as Figure 5 shown.

[0084] Embodiment 12

[0085] This embodiment provides a method for the regenerative resource treatment of oil-based drilling fluid. The difference between this method and that of Embodiment 10 is only that the demulsifier used is NP-9 instead of demulsifier BASF-L64.

[0086] The results of the thermal distillation temperature, thermal distillation time, and power consumption recorded by the smart electricity meter are as Figure 3 shown.

[0087] The results of the liquid phase recovery rate and the oil content rate of the remaining solid residue are as Figure 5 shown.

[0088] Embodiment 13

[0089] This embodiment provides a method for the regenerative resource treatment of oil-based drilling fluid. The difference between this method and that of Embodiment 10 is only that the catalyst used is KOH instead of demulsifier BASF-L64.

[0090] The results of the thermal distillation temperature, thermal distillation time, and power consumption recorded by the smart electricity meter are as Figure 3 shown.

[0091] The results of the liquid-phase recovery rate and the oil content rate of the remaining solid in the remaining solid residue are as follows Figure 5 shown

[0092] Example 14

[0093] This example provides a method for the regenerative resource treatment of oil-based drilling fluid. Among them, the difference between this method and that of Example 10 is only that the catalyst used is NaOH instead of the demulsifier BASF-L64

[0094] The results of the thermal distillation temperature, the thermal distillation time, and the power consumption recorded by the smart electricity meter are as follows Figure 3 shown

[0095] The results of the liquid-phase recovery rate and the oil content rate of the remaining solid in the remaining solid residue are as follows Figure 5 shown

[0096] Example 15

[0097] This example provides a method for the regenerative resource treatment of oil-based drilling fluid. Among them, the difference between this method and that of Example 10 is only that the catalyst used is CaCl 2 instead of the demulsifier BASF-L64

[0098] The results of the thermal distillation temperature, the thermal distillation time, and the power consumption recorded by the smart electricity meter are as follows Figure 3 shown

[0099] The results of the liquid-phase recovery rate and the oil content rate of the remaining solid in the remaining solid residue are as follows Figure 5 shown

[0100] Example 16

[0101] This example provides a method for the regenerative resource treatment of oil-based drilling fluid. Among them, the difference between this method and that of Example 10 is only that the catalyst used is FeCl 3 ·6H 2 O instead of the demulsifier BASF-L64

[0102] The results of the thermal distillation temperature, the thermal distillation time, and the power consumption recorded by the smart electricity meter are as follows Figure 3 shown

[0103] The results of the liquid-phase recovery rate and the oil content rate of the remaining solid in the remaining solid residue are as follows Figure 5 shown

[0104] Example 17

[0105] This example provides a method for the regenerative resource treatment of oil-based drilling fluid. Among them, the difference between this method and that of Example 10 is only that the catalyst used is CaO instead of the demulsifier BASF-L64

[0106] The results of the thermal distillation temperature, thermal distillation time, and power consumption recorded by the smart meter are as Figure 3 shown.

[0107] The results of the liquid-phase recovery rate and the oil content rate of the remaining solid in the remaining solid residue are as Figure 5 shown.

[0108] Example 18

[0109] This example provides a method for the regenerative resource treatment of oil-based drilling fluid. Among them, the difference between this method and that of Example 10 is only that the catalyst used is Fe 2 O 3 instead of the demulsifier BASF-L64.

[0110] The results of the thermal distillation temperature, thermal distillation time, and power consumption recorded by the smart meter are as Figure 3 shown.

[0111] The results of the liquid-phase recovery rate and the oil content rate of the remaining solid in the remaining solid residue are as Figure 5 shown.

[0112] Example 19

[0113] This example provides a method for the regenerative resource treatment of oil-based drilling fluid. Among them, the difference between this method and that of Example 1 is only that the catalyst used is CaO and the demulsifier BASF-L64 are used in cooperation. Based on the mass of the oil-based drilling fluid to be treated being 100%, the dosages of both the catalyst CaO and the demulsifier BASF-L64 are 1 wt%.

[0114] The results of the thermal distillation temperature, thermal distillation time, and power consumption recorded by the smart meter are as Figure 6 shown.

[0115] The results of the liquid-phase recovery rate and the oil content rate of the remaining solid in the remaining solid residue are as Figure 7 shown.

[0116] Example 20

[0117] This example provides a method for the regenerative resource treatment of oil-based drilling fluid. Among them, the difference between this method and that of Example 19 is only that the catalyst used is Fe 2 O 3 and the demulsifier BASF-L64 are used in cooperation, rather than the catalyst CaO.

[0118] The results of the thermal distillation temperature, thermal distillation time, and power consumption recorded by the smart meter are as Figure 6 shown.

[0119] The results of the liquid-phase recovery rate and the oil content rate of the remaining solid in the remaining solid residue are as Figure 7 shown.

[0120] Example 21

[0121] This example provides a method for the regenerative resource treatment of oil-based drilling fluids. The difference between this method and that of Example 19 is only that the catalyst used is CaCl 2 in synergy with the demulsifier BASF-L64, rather than CaO as the catalyst.

[0122] The results of the thermal distillation temperature, thermal distillation time, and power consumption recorded by the smart electricity meter are as Figure 6 shown.

[0123] The results of the liquid-phase recovery rate and the oil content rate of the remaining solids in the remaining solid residue are as Figure 7 shown.

[0124] Example 22

[0125] This example provides a method for the regenerative resource treatment of oil-based drilling fluids. The difference between this method and that of Example 19 is only that the catalyst used is FeCl 3 ·6H 2 O in synergy with the demulsifier BASF-L64, rather than CaO as the catalyst.

[0126] The results of the thermal distillation temperature, thermal distillation time, and power consumption recorded by the smart electricity meter are as Figure 6 shown.

[0127] The results of the liquid-phase recovery rate and the oil content rate of the remaining solids in the remaining solid residue are as Figure 7 shown.

[0128] Example 23

[0129] This example provides a method for the regenerative resource treatment of oil-based drilling fluids. The difference between this method and that of Example 19 is only that the catalyst used is NaOH in synergy with the demulsifier BASF-L64, rather than CaO as the catalyst.

[0130] The results of the thermal distillation temperature, thermal distillation time, and power consumption recorded by the smart electricity meter are as Figure 6 shown.

[0131] The results of the liquid-phase recovery rate and the oil content rate of the remaining solids in the remaining solid residue are as Figure 7 shown.

[0132] Example 24

[0133] This example provides a method for the regenerative resource treatment of oil-based drilling fluids. The difference between this method and that of Example 19 is only that the catalyst used is KOH in synergy with the demulsifier BASF-L64, rather than CaO as the catalyst.

[0134] The results of the thermal distillation temperature, thermal distillation time, and power consumption recorded by the smart electricity meter are as Figure 6 shown.

[0135] The results of the liquid phase recovery rate and the oil content rate of the remaining solid in the remaining solid residue are as Figure 7 shown.

[0136] Comparative Example 1

[0137] This comparative example provides a method for the regenerative resource treatment of oil-based drilling fluid. Among them, the difference between this method and Example 1 is only that the demulsifier BASF-L64 is not used, and the oil-based drilling fluid to be treated is directly subjected to thermal distillation.

[0138] The results of the thermal distillation temperature, thermal distillation time, and power consumption recorded by the smart electricity meter are as Figure 2 shown.

[0139] The results of the liquid phase recovery rate and the oil content rate of the remaining solid in the remaining solid residue are as Figure 4 shown.

[0140] Comparative Example 2

[0141] This comparative example provides a method for the regenerative resource treatment of oil-based drilling fluid. Among them, the difference between this method and Comparative Example 1 is only that: the pressure of the thermal distillation device is -0.09 MPa instead of -0.07 MPa.

[0142] The results of the thermal distillation temperature, thermal distillation time, and power consumption recorded by the smart electricity meter are as Figure 3 shown.

[0143] The results of the liquid phase recovery rate and the oil content rate of the remaining solid in the remaining solid residue are as Figure 5 shown.

[0144] By comparing each example with the comparative examples, it can be seen that the liquid phase recovery rate of thermal distillation after adding demulsifier / catalyst chemical agents is higher than that of direct thermal distillation without agents, the oil content rate of the remaining solid in the remaining solid residue of thermal distillation after adding demulsifier / catalyst chemical agents is lower than that of the remaining solid residue of direct thermal distillation without agents, and the power consumption of thermal distillation after adding demulsifier / catalyst chemical agents is lower than that of direct thermal distillation without agents. The oil content rate of the remaining solid in the remaining solid residue of thermal distillation after adding demulsifier / catalyst chemical agents is less than 1%. Therefore, the remaining solid residue can be used as building materials or for paving in oil fields, realizing the harmless treatment of oil-based drilling fluid. The reduction of energy consumption by the demulsification synergistic distillation treatment is more significant than that of the catalytic synergistic distillation treatment. This is because the catalyst can play a better catalytic role on the asphalt molecules in the asphaltene during the thermal distillation process, cracking the heavy oil components into light oil components, which can further promote the distillation of oil components and play a better promoting role in the thermal decomposition of oil-based drilling fluid.

[0145] The GC-MS analysis was performed on the liquid-phase recovered white oil in Examples 1 and 4 and Comparative Example 1, and the results are as Figure 8 shown. Through GC-MS analysis, it was found that adding demulsifiers and catalysts had no obvious effect on the microscopic substances of the liquid-phase recovered oil. Compared with the liquid-phase recovered oil without agents, the peak emergence of the liquid-phase recovered oil after adding agents was advanced by 2 min, but the basic substances remained unchanged, mainly alkene substances.

[0146] SEM and EDS analyses were performed on the remaining solid residues in Example 9 and Comparative Example 1, as Figure 9 shown. It was found that the microscopic structures of the remaining solid residues before and after adding agents were basically the same, with no obvious morphological differences; the basic elements contained were the same, no heavy metals and radioactive elements were detected, and the treated remaining solids met the requirements for laying oilfield well sites and well-flushing roads.

Claims

1. A method for recycling oil-based drilling fluid, wherein: The method includes: The oil-based drilling fluid to be treated is mixed with a demulsifier and / or a catalyst to obtain a mixture; wherein the demulsifier includes at least one of an ionic demulsifier and an organic non-ionic demulsifier, and the catalyst includes at least one of a salt-forming alkaline oxide, a metal hydroxide and a mixed metal salt; The mixture is subjected to thermal distillation to separate and recover the oily components.

2. The method according to claim 1, wherein: Based on the mass of the oil-based drilling fluid to be treated as 100%, the total amount of the demulsifier and the catalyst is 0.5-5%; Preferably, based on 100% of the mass of the oil-based drilling fluid to be treated, the total amount of the demulsifier and the catalyst is 1-3%.

3. The method according to claim 1, wherein: mixing the oil-based drilling fluid to be treated with a demulsifier and a catalyst to obtain a mixture; Preferably, based on the mass of the oil-based drilling fluid to be treated as 100%, the mass of the demulsifier is 0.5-4.5wt%, and the mass of the catalyst is 0.5-4.5wt%; More preferably, based on 100% of the mass of the oil-based drilling fluid to be treated, the mass of the demulsifier is 0.8-2.2 wt%, and the mass of the catalyst is 0.8-2.2 wt%.

4. The method according to claim 1, wherein: The demulsifier includes at least one of sodium dodecyl sulfonate, sodium dodecylbenzene sulfonate, Tween20, BASF-L64, Thg-9603, and NP-9.

5. The method according to claim 1, wherein: The demulsifier can be prepared by a preparation method comprising the following steps: using at least one of organic amine, fatty alcohol, polyol and resin as an initiator and performing block polymerization with at least one of ethylene oxide and propylene oxide to obtain the organic nonionic demulsifier.

6. The method according to claim 1, wherein: The salt-forming alkaline oxide includes at least one of calcium oxide and iron oxide.

7. The method according to claim 1, wherein: The metal hydroxide includes at least one of potassium hydroxide and sodium hydroxide.

8. The method according to claim 1, wherein: The metal salts include at least one of calcium chloride, ferric chloride, ferrous chloride and inorganic polyferric salts.

9. The method according to claim 1, wherein: The heating method of thermal distillation includes at least one of electromagnetic heating, microwave heating and fuel combustion heating; and / or The temperature of the thermal distillation is 300-350°C; and / or The time of the thermal distillation is 0.1-0.6h.

10. The method according to claim 1, wherein: The pressure of the thermal distillation is 0-0.09 MPa.

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