Harmless treatment method for drilling mud

Abstract

The invention provides a harmless treatment method for drilling mud, which comprises a cracking and dry distillation system, a condensation shunting system and a heat energy utilization system, the cracking and dry distillation system comprises a low-temperature distillation mixing screw, a medium-temperature distillation device, a high-temperature cracking furnace kiln and a hot blast stove, and the drilling mud passes through the low-temperature distillation mixing screw under the conditions of 0.1-0.5 pa and 150-200 DEG C; after water and oil are distilled, condensed and separated, materials are subjected to predistillation cracking in the environment of 250-300 DEG C through a medium-temperature distillation device and then subjected to the pyrolysis distillation process of 350-400 DEG C through a high-temperature cracking furnace kiln, formed pyrolysis tailings are fed into a hot blast stove to be subjected to high-temperature calcination of 800-1200 DEG C, and hot slag obtained after calcination is guided out and enters a heat energy utilization system. According to the method, the oil component of the oil-containing drilling mud is extracted as much as possible, meanwhile, the content of volatile matters in the tailings is lower than three thousandths, the leading-edge treatment concepts of energy utilization, productization circulating collection, high-temperature calcination of the solid tailings and the like are adopted and fused, and the method has good economical efficiency and environmental protection characteristics.

Description

Technical Field

[0001] The invention belongs to the technical field of drilling mud treatment, and in particular relates to a method for harmless disposal of drilling mud. Background Art

[0002] Hazardous wastes in environmental protection and governance are industrial wastes with hazardous characteristics. It does not exclude solid wastes with hazardous characteristics, which may have harmful effects on the environment or human health. Therefore, improper disposal of hazardous wastes will have a serious impact on the environment. Drilling mud is a solid waste of oil fields. Due to process requirements, a lot of chemical agents are added during the production process and it is listed as a hazardous waste.

[0003] At present, the domestic methods for treating drilling oil-based mud include oil pool storage, wet water washing, incineration, cracking, etc. The economic and environmental characteristics of the above methods are poor.

[0004] Based on this, a harmless disposal method for drilling mud is proposed. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a method for harmless disposal of drilling mud in view of the deficiencies of the above-mentioned prior art, so as to solve the problems raised in the above-mentioned background technology.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: a method for harmless disposal of drilling mud, comprising a cracking and distillation system, a condensation and diversion system and a heat energy utilization system;

[0007] The cracking and distillation system comprises a low-temperature distillation mixing screw, a medium-temperature distillation device, a high-temperature cracking furnace and a hot blast furnace, wherein the low-temperature distillation mixing screw, the medium-temperature distillation device and the high-temperature cracking furnace are sequentially connected in a sealed material delivery pipe;

[0008] The heat energy utilization system comprises a post-calcination hot slag diversion device and a cooling, conveying and heat exchanging device; the condensation diversion system comprises a condensation device and an oil collection system;

[0009] When the drilling mud passes through the low-temperature distillation mixing screw, it is low-temperature distilled at 0.1-0.5Pa and 150-200℃ to separate the low-temperature distillation gas and condensed water. The remaining materials are sent to the medium-temperature distillation device for primary distillation and cracking at 250℃-300℃ to separate the tail smoke and primary distillation gas. The tail smoke is processed and discharged through the collection and emission system. The remaining primary distillation materials are sent to the high-temperature cracking furnace for pyrolysis and distillation at 350℃-400℃ to obtain cracking distillation gas and pyrolysis tailings.

[0010] The pyrolysis tailings are sent to a hot blast furnace for high temperature calcination at 800°C-1200°C to obtain calcined hot slag;

[0011] The calcined hot slag enters the post-calcined hot slag diversion device of the heat energy utilization system and is divided into two parts. One part of the calcined hot slag is sent to the cooling conveying heat exchange device to obtain cold slag after cooling, and the other part of the calcined hot slag is sent to the low-temperature distillation mixing screw;

[0012] The low-temperature distillation gas, the primary distillation gas and the cracking distillation gas are sent to the condensation and diversion system to separate the cracking oil.

[0013] As a further illustration of the present invention, the uncondensed cracking non-condensable gas in the condensing device is connected to the hot blast furnace of the cracking and distillation system to provide energy for the hot blast furnace, and burns in the furnace to generate 800°C-1200°C heat energy.

[0014] As a further illustration of the present invention, the heat exchange air entering the cooling, conveying and heat exchange device is introduced into the hot blast furnace of the cracking and distillation system to provide hot combustion air for the hot blast furnace energy combustion. After passing through the calcined hot slag of the cooling, conveying and heat exchange device, the organic matter is converted and removed, the radioactivity of heavy metals is suppressed to form solid compounds, and the nutrient metals beneficial to plants form active calcined coke, which enters the cold slag for utilization and recovery.

[0015] As a further illustration of the present invention, the drilling mud and the diverted hot slag transported from the heat energy utilization system are mixed and contacted for heat exchange in a low-temperature distillation mixing spiral, raising the temperature of the drilling mud to 150°C-200°C, promoting the evaporation of free water in the drilling mud, and collecting and condensing the condensed water.

[0016] As a further illustration of the present invention, the low-temperature distillation mixing screw is connected to the condensate water collecting and discharging system, and the condensate water collection is respectively connected to the condensation device of the condensation diversion system and the tail smoke treatment system of the collection and discharging system, providing production water replenishment for the condensation device and the tail smoke treatment system.

[0017] As a further illustration of the present invention, the material dehydrated by spiral distillation from low-temperature distillation mixing enters the medium-temperature distillation device in a closed manner, undergoes initial distillation and cracking in a closed anaerobic environment at 250°C-300°C, and is connected to a condensation device through a sealed pipeline.

[0018] As a further illustration of the present invention, the material coming out of the medium-temperature distillation device enters the high-temperature cracking furnace in a sealed manner, undergoes high-temperature cracking and dry distillation, and causes the volatile oil and gas components above C6 in the material to be gasified, and is connected to the condensing device through a sealed pipeline.

[0019] As a further explanation of the present invention, the hot blast furnace supplies 800°C-1200°C thermal energy flue gas to the high-temperature cracking furnace at high temperature, so that the high-temperature cracking furnace obtains 350°C-400°C cracking and distillation thermal energy. The heat of the high-temperature tail smoke after the high-temperature cracking furnace heat is used is greater than 500°C, which is introduced into the medium-temperature distillation device of the cracking and distillation system, so that the medium-temperature distillation device obtains 250°C-300°C primary distillation thermal energy by waste heat utilization.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] The invention adopts the combination of low-temperature negative pressure distillation and medium- and high-temperature dry distillation and calcination processes. The front section distills and condenses water and oil under the conditions of negative pressure of 0.1-0.5 Pa and temperature of 150-200 DEG C., preliminarily cracks volatile components of organic matter under the conditions of temperature of 250-300 DEG C., and the rear section is subjected to high-temperature gasification and cracking at 350-400 DEG C, and then condenses and separates, collects cracking oil and cracking non-condensable gas, and calcines the remaining tailings in a hot blast furnace under the conditions of 800-1200 DEG C, so as to promote the complete gasification and combustion of a small amount of residual volatile organic matter in the tailings. The process extracts the oil component of the oil-containing drilling mud as much as possible, and makes the volatile matter content of the tailings less than 0.3%. The invention adopts and integrates the cutting-edge processing concepts such as energy utilization, product recycling collection, and high-temperature calcination of solid tailings, has good economic and environmental protection characteristics, consumes less operating energy, and can recover product pyrolysis oil, calcined slag, etc., and is economical and practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is the overall principle block diagram of the present invention.

[0023] Description of reference numerals:

[0024] 1-Condensation and diversion system; 2-Cracking and distillation system; 3-Heat energy utilization system. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] like Figure 1 As shown, the present invention provides a technical solution: a method for harmless disposal of drilling mud, comprising a cracking and distillation system 2, a condensation and diversion system 1 and a heat energy utilization system 3;

[0027] The cracking and distillation system 2 includes a low-temperature distillation mixing screw, a medium-temperature distillation device, a high-temperature cracking furnace and a hot blast furnace. The low-temperature distillation mixing screw, the medium-temperature distillation device and the high-temperature cracking furnace are sequentially connected in a sealed feed pipe;

[0028] The heat energy utilization system 3 includes a post-calcination hot slag diversion device and a cooling, conveying and heat exchange device; the condensation diversion system 1 includes a condensation device and an oil collection system;

[0029] When the drilling mud passes through the low-temperature distillation mixing screw, it is low-temperature distilled at 0.1-0.5Pa and 150-200℃ to separate the low-temperature distillation gas and condensed water. The remaining materials are sent to the medium-temperature distillation device for primary distillation and cracking at 250℃-300℃ to separate the tail smoke and primary distillation gas. The tail smoke is processed and discharged through the collection and emission system. The remaining primary distillation materials are sent to the high-temperature cracking furnace for pyrolysis and distillation at 350℃-400℃ to obtain cracking distillation gas and pyrolysis tailings.

[0030] The low-temperature distillation gas, the primary distillation gas and the cracking distillation gas are sent to the condensation and diversion system 1 to separate the cracking oil.

[0031] The pyrolysis tailings are sent to a hot blast furnace for high temperature calcination at 800°C-1200°C to obtain calcined hot slag;

[0032] The calcined hot slag enters the post-calcined hot slag diversion device of the heat energy utilization system 3 and is divided into two parts. One part of the calcined hot slag is sent to the cooling conveying heat exchange device to obtain cold slag after cooling, and the other part of the calcined hot slag is sent to the low-temperature distillation mixing screw;

[0033] Specifically, the heat energy utilization system 3 comprises a calcined hot slag diversion device and a cooling, conveying and heat exchanging device. The calcined hot slag is divided into half of the diverted hot slag in the calcined hot slag diversion device and transported to the low-temperature distillation mixing screw of the cracking and distillation system 2 to mix with the drilling mud for heat exchange. The drilling mud and the diverted hot slag transported by the heat energy utilization system 3 are mixed and contacted with the low-temperature distillation mixing screw for heat exchange, and the drilling mud is heated to 150°C-200°C, which promotes the evaporation of free water in the drilling mud, and the condensed water is collected and condensed;

[0034] The other half of the hot slag diverted by the hot slag diverting device after calcination enters the cooling, conveying and heat exchanging device. The heat exchange air entering the cooling, conveying and heat exchanging device is introduced into the hot blast furnace of the cracking and distillation system 2 to provide hot combustion air for the energy combustion of the hot blast furnace. After the hot slag after calcination passes through the cooling, conveying and heat exchanging device, organic matter is converted and removed, the radioactivity of heavy metals is suppressed to form solid compounds, and the nutrient metals beneficial to plants form active calcined coke, which enters the cold slag for utilization and recovery;

[0035] The condensation and diversion system 1 includes a condensing device and an oil collection system. The cracking and distillation gas cracked by the medium-temperature distillation device and the high-temperature cracking furnace of the cracking and distillation system 2 is introduced into the condensing device. The cracking and distillation gas is condensed into cracking oil through the condensing device. The cracking oil is collected and utilized by the oil collection system. The uncondensed cracking non-condensable gas in the condensing device is connected to the hot blast furnace of the cracking and distillation system 2 to provide energy for the hot blast furnace, and burns in the furnace to generate 800°C-1200°C heat energy;

[0036] The hot blast furnace supplies 800℃-1200℃ thermal energy flue gas to the high-temperature cracking furnace at high temperature, so that the high-temperature cracking furnace obtains 350℃-400℃ cracking and distillation thermal energy. The heat of the high-temperature tail smoke after the high-temperature cracking furnace is used is greater than 500℃, which is introduced into the medium-temperature distillation device of the cracking and distillation system 2, so that the medium-temperature distillation device obtains 250℃-300℃ primary distillation thermal energy by utilizing waste heat.

[0037] The cracking and distillation system 2, the condensation and diversion system 1 and the heat energy utilization system 3 are respectively connected to the collection and emission system, and the operations of tail smoke treatment and emission, condensed water collection and cold slag utilization are completed through the collection and emission system.

[0038] The low-temperature distillation mixing screw is connected to the condensate water of the collection and emission system. The condensate water collection is respectively connected to the condensation device of the condensation diversion system and the tail smoke treatment system of the collection and emission system to provide production water for the condensation device and the tail smoke treatment system, and can also be used as domestic water.

[0039] Embodiment, the collected drilling mud enters the low-temperature distillation mixing screw, is mixed with the calcined hot slag transported from the calcined hot slag diversion device, and is blended and creeps forward under the stirring of the low-temperature distillation mixing screw. The heat of more than 500°C in the calcined hot slag is transferred to the drilling mud during the blending process. During the movement of the low-temperature distillation mixing screw, the mixture gradually reaches a balance point of 150°C-200°C, and the free water contained in the drilling mud is evaporated and gasified, and is pumped to the condensed water collection system through a negative pressure of 0.1-0.5pa, which can be used as production and living sweeping and irrigation water;

[0040] The dry drilling mud material dehydrated by low-temperature distillation mixing spiral evaporation, i.e., drilling oil-containing dry material, is sealed and docked at the low-temperature distillation mixing spiral outlet, and introduced into the medium-temperature distillation device for primary distillation and cracking in a closed anaerobic environment of 250°C-300°C, and the volatile organic small and medium molecular chain substances in the drilling oil-containing dry material are decomposed and gasified, and then introduced into the condensation device of the condensation system through a pipeline;

[0041] The organic macromolecular chain substances that are not easy to volatilize continue to run into the 350℃-400℃ high-temperature cracking furnace. By raising the cracking temperature, the molecular chains are broken, decomposed and gasified, and then introduced into the condensation device of the condensation system through pipelines;

[0042] The cracked distillation gas introduced into the condensation device by the medium-temperature distillation device and the high-temperature cracking furnace is condensed into cracking oil in the condensation device and collected and utilized by the oil collection system. The cracked non-condensable gas that cannot be condensed is introduced into the hot blast furnace through a pipeline for combustion; the cracked non-condensable gas is burned in the hot blast furnace to generate 800℃-1200℃ high-temperature hot air, which is the thermal energy for cracking and dry distillation of the high-temperature cracking furnace. The tail gas temperature after heat extraction in the high-temperature cracking furnace is still greater than 500℃, and is introduced into the medium-temperature distillation device for waste heat reuse;

[0043] After the medium-temperature distillation device and the high-temperature cracking furnace, 90% of the volatile matter of the drilling oil-containing dry material is decomposed and removed, and the volume is reduced by 70%. The remaining 30% of the pyrolysis tailings still have a small amount of organic compounds, which are introduced into the hot blast furnace. After further high-temperature calcination at 800℃-1200℃, the organic compounds can be basically burned and removed, forming calcined hot slag with a heat content of more than 500℃. The calcined hot slag is introduced into the calcined hot slag diversion device and divided into two paths. One half is transported to the low-temperature distillation mixing screw to mix with the drilling mud, and the remaining other half is introduced into the cooling heat exchange conveying device, and the cooling conveying discharge is used as cold slag, and the heat exchange air is introduced into the hot blast furnace to supplement air and assist combustion;

[0044] The oilfield drilling mud can be effectively removed from the residual hydrocarbon organic components in the mud through the above-mentioned technical process, which has a good cost-effectiveness in terms of reduction, resource utilization and environmental protection. It is mainly aimed at drilling mud, but not limited to the treatment of drilling mud, and can be expanded to petroleum solid waste treatment and similar material treatment industries.

[0045] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0046] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for harmless disposal of drilling mud, characterized in that: It comprises a cracking and distillation system (2), a condensation and diversion system (1) and a heat energy utilization system (3); The cracking and distillation system (2) comprises a low-temperature distillation mixing screw, a medium-temperature distillation device, a high-temperature cracking furnace and a hot blast furnace. The high-temperature hot blast generated by the hot blast furnace is connected to the high-temperature cracking furnace through a pipeline; the low-temperature distillation mixing screw, the medium-temperature distillation device and the high-temperature cracking furnace are sequentially sealed and connected through a sealed feed pipe; The heat energy utilization system (3) comprises a calcined hot slag diversion device and a cooling, conveying and heat exchanging device; the condensation diversion system (1) comprises a condensation device and an oil collection system; When the drilling mud passes through the low-temperature distillation mixing screw, it is low-temperature distilled at 0.1-0.5Pa and 150-200℃. The distilled gas is discharged and cooled to form condensed water. The remaining materials are sent to the medium-temperature distillation device for primary distillation and cracking at 250℃-300℃. The primary distillation gas is introduced into the condensing device through a pipeline. The tail smoke is collected and discharged through the collection and emission system. The remaining primary distillation material is sent to the high-temperature cracking furnace for pyrolysis and distillation at 350℃-400℃ to obtain cracking distillation gas and pyrolysis tailings. The pyrolysis tailings are sent to a hot blast furnace for high temperature calcination at 800°C-1200°C to obtain calcined hot slag; The calcined hot slag enters the post-calcined hot slag diversion device of the heat energy utilization system (3) and is divided into two parts. One part of the calcined hot slag is sent to the cooling, conveying and heat exchanging device to obtain cold slag after cooling, and the other part of the calcined hot slag is sent to the low-temperature distillation mixing screw; The low-temperature distillation gas, the primary distillation gas and the cracking distillation gas are sent to a condensation and diversion system (1) to separate the cracking oil.

2. A method for harmless disposal of drilling mud according to claim 1, characterized in that: The hot blast furnace supplies 800°C-1200°C thermal energy flue gas to the high temperature cracking furnace, so that the high temperature cracking furnace obtains 350°C-400°C cracking and distillation thermal energy. The heat of the high temperature tail smoke after the high temperature cracking furnace uses the heat is greater than 500°C, which is introduced into the medium temperature distillation device of the cracking and distillation system (2), so that the medium temperature distillation device obtains waste heat.

3. The method for harmless disposal of drilling mud according to claim 1, characterized in that: The uncondensed cracking non-condensable gas in the condensing device is connected to the hot blast furnace of the cracking and distillation system (2) to provide energy for the hot blast furnace, and is burned in the furnace to generate heat energy of 800°C-1200°C. The heat exchange air entering the cooling, conveying and heat exchange device is introduced into the hot blast furnace of the cracking and distillation system (2) to provide hot combustion-supporting air for the hot blast furnace energy combustion. After the calcined hot slag passes through the cooling, conveying and heat exchange device, organic matter is converted and removed, the radioactivity of heavy metals is suppressed, and solid compounds are formed. Nutrient metals beneficial to plants form active calcined coke, which enters the cold slag for utilization and recovery.

4. The method for harmless disposal of drilling mud according to claim 1, characterized in that: The drilling mud and the diverted hot slag transported by the heat energy utilization system (3) are mixed and contacted with the low-temperature distillation mixing spiral for heat exchange, which heats the drilling mud to 150°C-200°C, promotes the evaporation of free water in the drilling mud, and collects and condenses the condensed water.

5. The method for harmless disposal of drilling mud according to claim 1, characterized in that: The low-temperature distillation mixing screw is connected to the condensate water of the collection and emission system, and the condensate water collection is respectively connected to the condensation device of the condensation diversion system and the tail smoke treatment system of the collection and emission system to provide production water for the condensation device and the tail smoke treatment system.

6. The method for harmless disposal of drilling mud according to claim 1, characterized in that: The materials dehydrated by spiral distillation from low-temperature distillation mixing enter the medium-temperature distillation device in a closed manner, undergo initial distillation and cracking in a closed anaerobic environment at 250℃-300℃, and are connected to the condensation device through a sealed pipeline.

7. The method for harmless disposal of drilling mud according to claim 1, characterized in that: The materials coming out of the medium-temperature distillation device enter the high-temperature cracking furnace in a sealed manner, and undergo high-temperature cracking and dry distillation to gasify the volatile oil and gas components above C6 in the materials, and are connected to the condensing device through a sealed pipeline.

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