New technology for on-line pickling of oilfield heating furnace

Abstract

The patent of the present invention is a new process for online pickling of oilfield heating furnaces. The oilfield heating furnaces include crude oil input valves, cleaning input valves, differential pressure gauges, cleaning output valves, crude oil output valves, steam input valves, steam generators, heaters or burners, crude oil inlet pipes, water supply pipes, sewage outlet pipes, crude oil outlet pipes, heating coils, and heating bodies. The patent of the present invention realizes online pickling and descaling without stopping the furnace on site by adding cleaning components, thereby improving the equipment utilization efficiency and avoiding the impact of stopping the furnace on on-site production. The patent has the characteristics of low cost, flexible setting, safe and convenient operation, etc., which meets the needs of oilfields for online maintenance and overhaul of heating furnaces without stopping the furnace.

Description

Technical Field

[0001] The invention relates to a process method suitable for completing pickling and descaling to improve heating efficiency without stopping an oil field heating furnace. Background Art

[0002] In oil production projects, it is necessary to heat the produced fluid from oil wells. The heating equipment is various types of heating furnaces. The most widely used ones are oil field phase change heating furnaces and oil field water jacket heating furnaces. In the process of heating the heating medium required by oil fields such as oil, gas, and water, scaling will appear on the inner wall of the heat exchange coil, which seriously affects the heat transfer efficiency of the heating furnace. In order to restore the process performance of the heating furnace, the oil field needs to regularly shut down the heating furnace for maintenance and pickling and descaling, which increases the equipment operating cost and reduces the equipment utilization efficiency.

[0003] Existing methods for cleaning the oilfield heating furnace: (1) Shut down and disassemble the heating furnace: disassemble the equipment at the original site, return the tube bundle to the maintenance center for pickling and cleaning, and repair the damaged parts. (2) Shut down and operate the heating furnace at the original site: transport the pickling equipment and maintenance tools to the original site, and after the equipment stops running, pickle and clean the equipment on site.

[0004] The above two processes and methods will cause the heating furnace equipment to stop running, resulting in reduced equipment utilization efficiency and high maintenance costs.

[0005] The oilfield heating furnace online pickling process and method of the present invention changes the above disadvantages of the existing oilfield heating furnace, and can carry out pickling and descaling without stopping the furnace, and can complete the pressure test inspection after pickling and descaling. It has the characteristics of high safety and reliability, simple operation, convenient installation, low cost, etc.

[0006] At present, the pickling of oilfield heating furnaces is chemically cleaned. When preparing for cleaning, the heating furnace equipment must stop running, and the parts required for pickling must be drained and purged, and then the process technology of periodically adding descaling agents and scale inhibitors is adopted. The existing chemical cleaning methods have the disadvantages of generating a lot of waste liquid and high recycling and treatment costs. Since early equipment widely used carbon steel materials, the parts that are prone to scaling are also carbon steel materials. This material will be severely thinned and corroded during the periodic pickling process, resulting in a significant reduction in the service life of the equipment; at the same time, since the equipment must be stopped for each pickling and cleaning, the equipment usage time is greatly reduced, the equipment idle time is greatly increased, and the equipment utilization efficiency is seriously reduced.

[0007] Based on the above background, an online pickling and descaling process method suitable for oilfield heating furnaces is urgently needed to improve equipment efficiency and comprehensive utilization rate of oilfield heating furnaces. Summary of the invention

[0008] The patent of this invention relates to a new process method for online pickling of oilfield heating furnaces, which is achieved by adding pickling process components to ordinary heating furnaces. The process components used are acid-resistant stainless steel washing materials, and relevant online pickling process pipelines and shut-off systems are set in the system. The process and method have the characteristics of low cost, flexible setting, safe and convenient operation, etc., and meet the needs of online chemical pickling of oilfield heating furnaces without stopping the furnace.

[0009] A new process method for online pickling of an oilfield heating furnace, the oilfield heating furnace comprises a crude oil input valve, a cleaning input valve, a differential pressure gauge, a cleaning output valve, a crude oil output valve, a steam input valve, a steam generator, a heater or burner, a crude oil inlet pipeline, a water supply port pipeline, a sewage outlet pipeline, a crude oil outlet pipeline, a heating coil, a heating body, a heat exchanger A, and a heat exchanger B; the characteristics are: the heat exchanger A comprises a crude oil input valve, a cleaning input valve, a differential pressure gauge, a cleaning output valve, a crude oil output valve, and a steam input valve, the structure of the heat exchanger B is the same as that of the heat exchanger A, the crude oil input valve and the cleaning input valve and the heat exchanger The coil is connected, the cleaning input valve is connected to the heat exchange coil, the cleaning input valve and the crude oil input valve are connected to the differential pressure gauge, the differential pressure gauge is connected to the cleaning output valve, the cleaning output valve is connected to the crude oil output valve, and the crude oil output valve is connected to the crude oil output pipeline; the heat exchange coil is connected to the steam input valve, the crude oil inlet pipeline is connected to the crude oil input valve of heat exchanger A and heat exchanger B, the crude oil outlet pipeline is connected to the steam input valve of heat exchanger A and heat exchanger B, the water replenishment pipe is connected to the heating body, the heating body is connected to the heater or burner, the sewage outlet pipe is connected to the heating body, and the heating body includes steam, water, and a steam generator.

[0010] The oilfield heating furnace online pickling process and method are applicable to oilfield heating furnaces with two or more sets of heat exchange coils, and the required working state is determined by switching the pipelines and valves according to the heating effect and the working state of the heating furnace. When the heating furnace is in operation, one set of heat exchange coils connected to the heating furnace is pickled and descaled. The other set of heat exchange coils or multiple sets work normally.

[0011] Beneficial effects of the invention patent:

[0012] 1. By adding cleaning components, online pickling and descaling can be carried out without stopping the furnace, thereby improving the efficiency of equipment use and avoiding the impact of furnace shutdown on on-site production.

[0013] 2. The pickling injection quick connection port is used to quickly connect the pickling system through a hose, avoiding on-site disassembly of equipment and replacement of sealing gaskets, saving maintenance time and maintenance transportation and maintenance costs.

[0014] 3. A differential pressure meter (including differential pressure transmitter) is installed at the inlet and outlet of the heat exchange component. The differential pressure signal can be connected to the control system. The size of the differential pressure value is directly proportional to the degree of scaling in the pipeline. By measuring the differential pressure value, the pickling time and cycle of the heat exchange component can be determined intuitively. Grassroots operators organize online pickling and maintenance of the oilfield heating furnace according to the differential pressure value or the prompt of the control system.

[0015] 4. The patent of the present invention has the characteristics of low cost, flexible setting, safe and convenient operation, etc., which meets the needs of the oil field for online maintenance and overhaul of the heating furnace without stopping the furnace. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a new process structure diagram of online pickling of oil field heating furnaces in the present invention.

[0017] Figure 1 In the structure diagram: 1. Crude oil input valve; 2. Cleaning input valve; 3. Differential pressure gauge; 4. Cleaning output valve; 5. Crude oil output valve; 6. Steam input valve; 7. Steam generator; 8. Heating or burner; 9. Crude oil inlet pipeline; 10. Water replenishment pipeline; 11. Sewage outlet pipeline; 12. Crude oil outlet pipeline; 13. Heat exchange coil; 14. Heating body; 15. Heat exchanger A; 16. Heat exchanger B. DETAILED DESCRIPTION

[0018] The invention discloses a novel process for online pickling of an oilfield heating furnace, wherein the oilfield heating furnace comprises a crude oil input valve 1, a cleaning input valve 2, a differential pressure gauge 3, a cleaning output valve 4, a crude oil output valve 5, a steam input valve 6, a steam generator 7, a heating or burner 8, a crude oil inlet pipeline 9, a water supply pipeline 10, a sewage outlet pipeline 11, a crude oil outlet pipeline 12, a heat exchange coil 13, a heating body 14, a heat exchanger A, and a heat exchanger B; the characteristics are as follows: the crude oil input valve 1, the cleaning input valve 2 and the heat exchange coil 13 are connected, the cleaning output valve 4 is connected to the heat exchange coil 13, the cleaning output valve 4 and the crude oil The input valve 1 is connected to the differential pressure gauge 3, the differential pressure gauge 3 is connected to the cleaning output valve 4, the cleaning output valve 4 is connected to the crude oil output valve 5, and the crude oil output valve 5 is connected to the crude oil outlet pipeline 12; the heat exchange coil 13 is connected to the steam input valve 6, the crude oil inlet pipeline 9 is connected to the crude oil input valve 1 of the heat exchanger A and the heat exchanger B, the crude oil outlet pipeline 12 is connected to the steam input valve 6 of the heat exchanger A and the heat exchanger B, the water replenishment pipe 10 is connected to the heating body 14, the heating body 14 is connected to the heater or burner 8, the sewage outlet pipe 11 is connected to the heating body 14, and the heating body 14 includes steam, water, and a steam generator 7.

[0019] The patent of this invention is applicable to the oilfield heating furnace in the oilfield surface engineering. The heat exchanger of the heating furnace is pickled and descaled online without stopping the furnace. The specific features are:

[0020] like Figure 1 As shown, the oilfield heating furnace includes: a heating body 14 and heat exchangers A15 and B16. The heating body 14 is composed of a heater or burner 8, a steam generator 7, a heating medium (usually water), a steam transmission circulation pipeline and a working valve.

[0021] like Figure 1 As shown, the steam generator 7 of the furnace body is heated by a heater or burner 8. The steam generator 7 is a container containing a heating medium (usually water). The steam generated by the steam generator 7 is transported to the heat exchanger A15 and the heat exchanger B16 through a pipeline and undergoes a heat exchange cycle.

[0022] like Figure 1 As shown, the heat exchanger includes two or more sets of heat exchangers A and B, each of which includes a heat exchange coil 13. The online pickling process and method of the present invention is described with two sets of heat exchangers.

[0023] like Figure 1 As shown, the heat exchanger components are: heat exchanger A15 contains heat exchange coils, and heat exchanger B16 contains heat exchange coils.

[0024] like Figure 1 As shown, the heat exchanger tube is additionally provided with a differential pressure gauge 3, which may be a diaphragm-type differential pressure gauge or a differential pressure transmitter or a similar sensor or instrument capable of displaying and measuring differential pressure.

[0025] like Figure 1 As shown, the heat exchanger A15 and the heat exchanger B16 of the oilfield heating furnace contain at least two or more sets of heat exchangers, and each set of heat exchanger contains a set of heat exchange coils 13.

[0026] like Figure 1 As shown, the cleaning input valve 2 and the cleaning output valve 4 are installed on the scaling side, that is, the pipe side, with cleaning liquid input and output valves made of acid-resistant stainless steel materials, which can reduce the corrosion and thinning of heat exchange components during pickling, extend the life of heat exchange components, and improve heat exchange efficiency. Acid-resistant stainless steel materials or other acid-resistant and durable materials are used to facilitate the switching between the heater cleaning process operation state and the normal working state.

[0027] When steam is delivered to the heat exchanger through the pipeline, the working steam input valve 6, the heated medium crude oil input valve 1, and the heated medium crude oil output valve 5 in the heat exchanger A15 are opened, and the heating furnace works at full load. On the contrary, the above valves are closed, and the heating furnace works at a stopped state.

[0028] When steam is transported to the heat exchanger through the pipeline, the working steam input valve 6 in the heat exchanger A15 is opened and the steam input valve 6 in the heat exchanger B16 is closed, the heated medium crude oil input valve 1 is opened, and the heated medium crude oil output valve 5 is opened. The working state of the heating furnace is: the heat exchanger A15 is turned on and running, and the heat exchanger B16 is turned off and running.

[0029] When steam is transported to the heat exchanger by the pipeline, the working steam input valve 6 in the heat exchanger A15 is opened, the crude oil input valve 1 of the heated medium is opened and the crude oil input valve 1 in the heat exchanger B16 is closed, the crude oil output valve 5 of the heated medium in the heat exchanger A15 is opened and the crude oil output valve 5 in the heat exchanger B16 is closed, and the working state of the heating furnace is: the heat exchanger B16 is turned on and running, and the heat exchanger A15 is turned off and running.

[0030] When the heat exchanger A15 is turned on and running, and the heat exchanger B16 is turned off and running; the heat exchange coil cleaning input valve 2 and the heat exchange coil cleaning output valve 4 are opened to clean the heat exchanger B16.

[0031] When the heat exchanger B16 is turned on and the heat exchanger A15 is turned off, the heat exchange coil cleaning input valve 2 and the heat exchange coil cleaning output valve 4 are opened to clean the heat exchanger A15.

[0032] The process and method for online pickling of the oilfield heating furnace is that uniform heat transfer during the phase change of the medium in the pipeline will form uniform scaling, and as the inner diameter of the heating coil is scaled, it will decrease, resulting in an increase in the pressure difference between the inlet and outlet of the pipe. When the differential pressure gauge 3 installed on the heat exchange coil 13 and the heat exchange coil 13 is equipped with a differential pressure gauge 3, the pressure gauge value is greater than 0, indicating that the heat exchange coil 13 is blocked or scaled, and the larger the pressure gauge value, the greater the degree of blockage or scaling of the heat exchange coil 13. The user can arrange to clean the heat exchange coil 13 according to the actual production situation. It is also possible to set a pressure difference alarm value to prompt the oilfield heating furnace to enter the online pickling cycle.

[0033] Selection of the cleaning liquid: The heat exchange coil is cleaned with a general pickling liquid, generally a nitric acid solution of a certain concentration, and a special cleaning liquid can also be used according to actual conditions.

[0034] The heat exchange coil 13 in the heat exchanger is a target object that needs to be cleaned due to scaling.

[0035] The implementation of the oilfield heating furnace online pickling process and method is to clean the heat exchange coil 13 process flow:

[0036] 1. First, use compressed air to purge the cleaned heat exchange coil 13 to purge the particles attached to the inner wall of the pipeline. After the purge is completed, connect the pickling liquid circulation pipeline.

[0037] 2. After the connection of the pickling liquid circulation pipeline is completed, the cleaning input valve 2 and the cleaning output valve 4 are opened to fill the heat exchange coil 13 with the pickling liquid, and the scale in the heat exchange coil 13 is chemically passivated. According to the situation of the chemical passivation reaction, the input and output valves can be appropriately closed to allow the passivation to react fully, and the operation is repeated and the pickling liquid is circulated until the scale on the wall of the heat exchange coil 13 is removed.

[0038] 3. After the scale on the wall of the heat exchange coil 13 is removed, the cleaned heat exchange coil 13 is cleaned with clean water or a special detergent.

[0039] 4. After the wall of the heat exchange coil 13 is cleaned, compressed air is used again to purge the cleaned heat exchange coil 13. The heat exchange coil cleaning process is now completed.

[0040] The cleaning circulation pipeline can be composed of special cleaning equipment and machines, or acid-resistant and stain-resistant components: it consists of pipelines with quick-connect connectors, cleaning circulation pumps, and dirty liquid separation tanks.

[0041] The patent of the present invention is not limited to the above-mentioned optimal implementation mode. Anyone can derive other various forms of products under the inspiration of the present invention. However, no matter what changes are made in its shape or structure, any technical solution that is the same or similar to that of the present application falls within the protection scope of the present invention.

Claims

1. A new process for online pickling of an oilfield heating furnace, the oilfield heating furnace comprising a crude oil input valve (1), a cleaning input valve (2), a differential pressure gauge (3), a cleaning output valve (4), a crude oil output valve (5), a steam input valve (6), a steam generator (7), a heater or a burner (8), a crude oil inlet pipeline (9), a water supply pipeline (10), a sewage outlet pipeline (11), a crude oil outlet pipeline (12), a heat exchange coil (13), a heating body (14), a heat exchanger A (15), and a heat exchanger B (16); the characteristics are: The crude oil input valve (1), the cleaning input valve (2) and the heat exchange coil (13) are connected, the cleaning input valve (2) and the heat exchange coil (13) are connected, the cleaning input valve (2) and the crude oil input valve (1) are connected to a differential pressure gauge (3), the differential pressure gauge (3) is connected to a cleaning output valve (4), the cleaning output valve (4) is connected to a crude oil output valve (5), and the crude oil output valve (5) is connected to a crude oil outlet pipeline (12); the heat exchange coil (13) and the steam input valve (6) are connected ), the crude oil inlet pipe (9) is connected to the crude oil input valve (1) of the heat exchanger A (15) and the heat exchanger B (16), the crude oil outlet pipe (12) is connected to the steam input valve (6) of the heat exchanger A (15) and the heat exchanger B (16), the water replenishment pipe (10) is connected to the heating body (14), the heating body (14) is connected to the heater or burner (8), the sewage outlet pipe (11) is connected to the heating body (14), and the heating body (14) includes steam, water , a steam generator (7); the heating body (14) is composed of a heater or burner (8), a steam generator (7), a heating medium, a steam transmission circulation pipeline and a working valve; the steam generator (7) of the furnace body is heated by the heater or burner (8), the steam generator (7) is a container containing a heating medium, and the steam generated by the steam generator (7) is transmitted to the heat exchanger A (15) and the heat exchanger B (16) through a pipeline to perform a heat exchange cycle; when the heat exchanger A (15) is turned on and operated and the heat exchanger B (16) is turned off and operated, the heat exchange coil (13) cleaning input valve (2) and the heat exchange coil (13) equipped with a cleaning output valve (4) are opened to clean the heat exchanger B (16); when the heat exchanger B (16) is turned on and operated and the heat exchanger A (15) is turned off and operated, the heat exchange coil (13) cleaning input valve (2) and the heat exchange coil (13) cleaning output valve (4) are opened to clean the heat exchanger A (15).

2. The novel process for online pickling of oilfield heating furnaces as claimed in claim 1 is characterized in that: The additional differential pressure gauge (3) may be a diaphragm type differential pressure gauge or a differential pressure transmitter.

3. The novel process for online pickling of oilfield heating furnaces as claimed in claim 1 is characterized in that: First, compressed air is used to purge the cleaned heat exchange coil to purge the particles attached to the inner wall of the pipeline. After the purge is completed, the pickling liquid circulation pipeline is connected. After the connection of the pickling liquid circulation pipeline is completed, the cleaning input valve (2) and the cleaning output valve (4) are opened to fill the heat exchange coil with pickling liquid, and the scale in the heat exchange coil (13) is chemically passivated. According to the situation of the chemical passivation reaction, the input and output valves can be closed to allow the passivation to react fully. The operation is repeated and the pickling liquid is circulated until the scale on the wall of the heat exchange coil is removed. After the scale on the wall of the heat exchange coil is removed, the cleaned heat exchange coil (13) is cleaned with clean water or a special detergent. After the wall of the heat exchange coil (13) is cleaned, the cleaned heat exchange coil (13) is purged with compressed air again. At this point, the heat exchange coil cleaning process is completed. The cleaning circulation pipeline is composed of a pipeline with a quick-connect joint, a cleaning circulation pump, and a dirty liquid separation reservoir.

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