A pollution-free high-temperature nitrogen cleaning operation method and device for pumping wells

Abstract

A pollution-free high-temperature nitrogen cleaning operation method and device for oil pumping wells, relating to a cleaning method, in which high-temperature nitrogen produced by a nitrogen generator is mixed with high-pressure water injection or steam produced by a steam machine in proportion to form a mixed gas of high-temperature nitrogen and steam After pressurization, the box-integrated pollution-free high-temperature nitrogen cleaning device for pumping wells, which integrates the sucker rod airtight cleaning device, the tubing inner wall cleaning device, the tubing outer wall cleaning device, the nitrogen making room, the operating room and the generator set, respectively The sucker rod, the inner wall of the oil pipe and the outer wall of the oil pipe are cleaned continuously without pollution, and the cleaning liquid can be completely recovered. Cleaning technology and cleaning fluid recovery technology are the core, and finally realize the closed cleaning of the sucker rod, the inner wall of the oil pipe and the outer wall of the oil pipe, the complete recovery of the cleaning liquid, and zero waste of crude oil.

Description

technical field [0001] The invention relates to a cleaning device, in particular to a pollution-free high-temperature nitrogen cleaning operation method and device for an oil pumping well. Background technique [0002] Minor workover of oil wells is the core means of maintaining production and taking measures to increase production in oil fields. The cleaning of the inner and outer walls of the tubing and the sucker rod is the most basic and critical part; in the oil field production, the waxing and scaling of the tubing and the sucker rod are very serious, which makes the oil flow channel gradually smaller or even blocked, resulting in The output of the oil well is reduced or even shut down. In the case of severe wax formation and scaling, the pressure in the oil pipe will increase, which will increase the load on the downhole oil pump, shorten the service life of the oil well, and affect the normal production of the oil well. Therefore, the oil pipe and pumping The cleani...

AI Technical Summary

Problems solved by technology

The disadvantages of this method are: (1) when heating, the fume and exhaust gas produced by oil and other sundries are large, causing serious pollution and affecting people and the environment; (2) fires are prone to occur; (3) the heating temperature is not easy to determine, the temperature If the temperature is too high, the metallographic structure of the oil pipe body will be damaged, and if the temperature is too low, the heating effect will not be achieved.

The disadvantages of this method are: (1) the pressure generated during cleaning is very high, which will cause great danger to the operators; (2) the nozzle is a vulnerable part, which needs to be replaced frequently, and the work efficiency is low; (3) the water consumption huge, resulting in huge energy consumption

The disadvantage of this cleaning method is: once the internal mechanical transmission part of the device fails, the maintenance time will be longer;

[0008] The above-mentioned conventional mechanical wax removal and scale removal methods are not only ineffective, but also affect the production of oil wells. The cost of chemical wax removal is high, the cost of heat carrier cleaning is too high, the thermal efficiency is low, the use of more cleaning fluid, and the drainage cycle of the well is more than three days , and will cause damage to sensitive oil layers. In short, the traditional cleaning methods have the disadvantages of many equipments, high energy consumption, low efficiency, large emission pollution, difficult operation, and heavy follow-up cleaning work.

[0009] In addition, during the process of wax removal, a large amount of crude oil is brought out of the wellhead with the sucker rod string. After the crude oil lands, it will pollute the natural environment and waste resources. Currently, when cleaning the oil pipe or sucker rod on the well site, it is usually laid on the ground Anti-seepage materials, construction of cofferdams to prevent oil and water spillage, and installation of oil guide trenches and recovery ponds in the construction area. These conventional protective measures cannot fundamentally solve the problem of oil and water not landing in the operation process. , plastic cloth and other pollution problems are very prominent, causing economic burdens and environmental risks to both parties in the construction

[0010] The patent application with the publication number CN103821470A discloses a process method for flushing wells by injecting hot nitrogen into the oil well, specifically disclosing that: after the continuous high-pressure nitrogen gas produced by the nitrogen production train unit is heated to the required temperature by the nitrogen heating device, the hot nitrogen gas passes through the connection Manifolds and wellhead devices are injected downhole for well flushing operations to achieve the purpose of wax removal, scale removal, plugging removal or heavy oil viscosity reduction, drainage assistance, and improvement of oil well production. However, the shortcomings of this application are: (1) only through injection High-temperature nitrogen can only melt dirt such as oil wax, but cannot wash away or carry out the melted dirt, and the dirt will slide down the pipe wall, resulting in incomplete decontamination; (2) The application injects nitrogen into the casing, only It can directly melt the oil on the outer wall of the oil pipe at high temperature, and the oil on the inner wall of the oil pipe and the sucker rod cannot be removed, especially the nitrogen in the inner wall of the oil pipe is running upwards, which is not conducive to the discharge of dirt; and nitrogen heating devices are arranged on the well site of the oil well. It is known that there are many tank components of the nitrogen generator group, which are large and heavy, and difficult to carry.

[0011] The patent application with the publication number CN107420068A discloses a high-temperature nitrogen wax removal device and a wax removal process. It specifically discloses that the nitrogen heating equipment is connected to the oil well casing inlet of the well washing operation through a high-temperature and high-pressure nitrogen pipeline, and the high-temperature nitrogen is self-continuous The oil pipe flows out and passes through the waxing point of the oil pipe. The wax melts and is taken out of the oil well by high-temperature nitrogen to complete the wax removal process of positive injection. If it is taken out of the oil well, it is impossible to guarantee the complete discharge of oil wax and other dirt, and the exhaust gas is mixed with oil wax and other substances to pollute the environment, and there is no waste gas recovery device; When the direct high temperature melts, the oil stains on the inner wall of the oil pipe and the sucker rod cannot be removed, especially the nitrogen in the inner wall of the oil pipe is running upwards, which is not conducive to the discharge of dirt; (3) The required nitrogen temperature is relatively high, and the high temperature nitrogen In the way of injection and return, the heat loss is large, and it needs to consume a lot of energy to ensure that the oil wax can be melted and the oil wax can be discharged. The thick oil wax cannot be completely removed, resulting in poor cleaning effect; (4) The application is made Nitrogen booster and nitrogen heating equipment have many components, are bulky and heavy, and are difficult to handle

[0012] The patent application with the publication number CN105114035B discloses an on-line cleaning process for oil pipes and sucker rods in well workover operations. It specifically discloses: first use 20 cubic meters of clean water to kill the well,...the steam heat source device heats the water to 80°C-90°C 1m per hour after °C 3 -2m 3 The flow of water is supplied to the sucker rod cleaner, and the wax and dirty oil on the outer wall of the sucker rod flow to the screen pipe with the water flow and return to the wellhead with the overflow in the well, and are pumped to the environmental protection box to complete the cleaning of the sucker rod In the same way, the outer wall of the oil pipe is cleaned by hot water. However, the disadvantages of this application are: (1) The application uses hot water to clean a large amount of water, which wastes resources and causes a large amount of water to be injected into the well during the cleaning process. , so that when the pumping unit is operating, it is necessary to pump out a large amount of water injected into the cleaning, resulting in a waste of useless work for the pumping unit; (2) The temperature is 80°C-90°C. The wax is melted and cleaned; (3) This application can only realize the cleaning of the sucker rod and the outer wall of the tubing, but cannot clean the inner wall of the tubing

[0014] 1. At present, the function of the device used in the cleaning process is single, and the cleaning effect is not good after cleaning with the current cleaning device. There is no equipment that can clean the sucker rod, the inner wall of the oil pipe, and the outer wall of the oil pipe. In order to effectively carry out oil production work , it is necessary to propose a new type of cleaning equipment in the workover process

[0015] 2. During the inspection and cleaning process of the pumping unit well, a large amount of crude oil is pulled out of the sucker rod and taken out of the wellhead with the sucker rod string, which will waste a lot of crude oil resources and damage economic benefits

[0016] 3. In the prior art, the oil well needs to be killed with clean water before repairing, which cannot be repaired in time, which reduces the work efficiency. At the same time, the killing fluid may pollute the oil layer and affect the normal oil production of the oil well after the repair

[0017] 4. Due to the fact that clean water is required for oil well repairing at present, after the repairing, when the oil well starts pumping, the first liquid pumped out is the water injected before, which takes a lot of time to pump out, and it is useless, resulting in waste of resources

[0018] 5. At present, when using a high-temperature wax removal vehicle to remove wax from sucker rods, the site after wax removal will be polluted. The existing prevention methods are: laying anti-seepage cloth on the surface or digging overflow trenches. This method not only has limited effects, It is also easy to cause secondary pollution. It takes a long time to remove the wax on the ground. At the same time, the wax removal vehicle needs to work for a long time, which consumes a lot of energy and is not conducive to environmental protection.

[0019] 6. In the prior art, when cleaning the sucker rods and oil pipes, the sucker rods need to be taken out from the ground, cleaned one by one, and then continue to work after cleaning, a large amount of heat energy is consumed in the process, and at the same time, the sucker rods cannot be cleaned during the cleaning process. work, so that the pumping work is not continuous

[0020] 7. At present, during the pumping well inspection and cleaning operation, the pumping well contains a large amount of hydrogen sulfide and other gases, and there are safety hazards such as fire and explosion during maintenance and cleaning. There are many problems in the construction process. At the same time, through the exposure of a large amount of hydrogen sulfide gas during the maintenance and cleaning process, it will pollute the environment, which is not in line with today's green environmental protection concept

[0021] 8. At present, in the wax removal process, the wax removal vehicles and various tools used, the anti-seepage cloth used in the cleaning process, the well site cleaning after the construction of conventional operation wells, oil and soil recovery and treatment, etc. all require economic expenditure, and the economic The investment is very large, which is not conducive to improving economic efficiency

[0022] To sum up, there are still many problems in the on-site construction process of oilfield workover operations, which lead to waste of resources. In order to solve the above problems and improve the work efficiency and economic benefits of oilfield workover operations, it is necessary to propose a new application Devices for oilfield workover operations

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