A mobile liquid nitrogen pump skid

Abstract

The mobile liquid nitrogen pump skid comprises a cryogenic liquid pump, an electric control cabinet, a high-pressure vaporizer, an oil tank, a high-pressure thermal oil electric heater and a generator set arranged in a carriage; the high-pressure thermal oil electric heater comprises an oil tank with a heating pipe inside; one side of the cryogenic liquid pump is first connected to the liquid nitrogen inlet pipe, and the other side is connected to the high-pressure vaporizer through the pump liquid outlet pipe, the high-pressure vaporizer is connected to the high-pressure thermal oil electric heater through a pipeline, the high-pressure thermal oil electric heater is also connected to the generator set, the electric control cabinet is electrically connected to the cryogenic liquid pump and the generator set respectively, a frequency converter is arranged in the electric control cabinet, and the cryogenic liquid pump is frequency-controlled; the high-pressure thermal oil electric heater is also connected to the nitrogen outlet pipe and the electric control cabinet line respectively; a smoke exhaust system heat recovery device is arranged in the oil tank, the generator set is provided with a smoke exhaust pipe, and the smoke exhaust pipe is connected to the smoke exhaust system heat recovery device. The system is easy to move and can better purge and pressure test the oil pipeline.

Description

Technical Field

[0001] The invention relates to the field of petroleum industry, and in particular to a mobile liquid nitrogen pump skid. Background Art

[0002] In the modern oil industry, the rapid development of nitrogen technology has made it widely used in many aspects of production. Compared with conventional methods, the use of nitrogen to treat oil wells and oil layers is safe, time-saving, fast, efficient, and has a high success rate. It is not only suitable for conventional oil reservoirs, but also has a unique role in special oil and gas reservoirs such as low pressure, low permeability, and clay cementation. Based on the characteristics of low density, good stability, and easy compression of nitrogen, it has a wide range of applications in improving recovery, drilling, perforating, production increase measures, and well repair.

[0003] In recent years, with the increasing demand for domestic oil and natural gas, the demand for gas pipeline purging equipment has become increasingly greater. Nitrogen is used to purge the pipeline within a certain pressure range or to test the pipeline pressure before use. Nitrogen at a certain pressure is injected into the pipeline to be purged to meet the needs of pipeline purging or pipeline pressure testing. In order to meet the special needs of the market, it is imperative to develop mobile liquid nitrogen pump skid equipment. Summary of the invention

[0004] In order to solve the above technical problems, we proposed a mobile liquid nitrogen pump skid to achieve the purpose of convenient mobility and better purge the oil pipeline.

[0005] To achieve the above object, the technical solution of the present invention is as follows:

[0006] A mobile liquid nitrogen pump skid, comprising a cryogenic liquid pump, an electric control cabinet, a high-pressure vaporizer, an oil tank, a high-pressure thermal oil type electric heater and a generator set arranged in a carriage; the cryogenic liquid pump is arranged near one side of the rear of the vehicle, the electric control cabinet is arranged on the other side of the rear of the vehicle, the high-pressure vaporizer is arranged in the middle of the carriage, the generator set is arranged near one side of the head of the carriage, the high-pressure thermal oil type electric heater is arranged on the other side of the head of the vehicle, and the high-pressure thermal oil type electric heater comprises an oil tank and a heating pipe arranged in the oil tank;

[0007] One side of the cryogenic liquid pump is first connected to the liquid nitrogen inlet pipe, and the other side is connected to the high-pressure gasifier through the pump liquid outlet pipe. The high-pressure gasifier is connected to the high-pressure thermal oil electric heater through a pipeline. The high-pressure thermal oil electric heater is also connected to the generator set. The electric control cabinet is electrically connected to the cryogenic liquid pump and the generator set respectively. The electric control cabinet is provided with a frequency converter, and the cryogenic liquid pump is frequency-controlled. The high-pressure thermal oil electric heater is also connected to a nitrogen outlet pipe and an electric control cabinet line respectively. The oil tank is provided with a smoke exhaust system heat recovery device, and the generator set is provided with a smoke exhaust pipe, which is connected to the smoke exhaust system heat recovery device. The cryogenic liquid pump is also connected to a liquid nitrogen vent pipe, and a vent valve is provided on the liquid nitrogen vent pipe. A damper is provided on the pump liquid outlet pipe. A liquid nitrogen fast inlet pipe is also connected to the pump liquid outlet pipe between the damper and the high-pressure gasifier. A safety valve, a pressure gauge and a temperature gauge are also provided on the liquid nitrogen delivery pipeline between the high-pressure vaporizer and the high-pressure thermal oil electric heater. The pressure gauge and the temperature gauge are both connected to the electrical control cabinet by electrical signals.

[0008] Preferably, an outlet flow meter is provided on the pipeline between the high-pressure thermal oil electric heater and the nitrogen outlet pipe, and the outlet flow meter is connected to a monitoring unit, the monitoring unit includes a thermometer, a pressure gauge and a temperature probe, and the monitoring unit is connected to the electrical control cabinet by electrical signals.

[0009] Preferably, a safety valve and an outlet pressure gauge are also provided on the liquid nitrogen delivery pipeline between the outlet flow meter and the high-pressure thermal oil electric heater.

[0010] Preferably, the liquid nitrogen inlet pipe and the nitrogen outlet pipe are two pipes connected in parallel, and both pipes are provided with stop valves.

[0011] Through the above technical scheme, when the present invention is put into use, nitrogen is input into the system from liquid nitrogen stored in a mobile tank truck, then pressurized to the required pressure by a low-temperature liquid nitrogen pump, and heated to the required temperature by a liquid nitrogen vaporizer, and then output and injected into a pipeline that needs to be purged or pressure tested. This system is used to inject nitrogen of a certain pressure into a pipeline that needs to be purged before using the oil pipeline, and perform purging work within a certain pressure range or pressure testing on the pipeline to meet the needs of pipeline purging or pipeline pressure testing. The adjustment of the nitrogen flow rate is achieved by adjusting the output frequency of the frequency converter, thereby adjusting the rotation speed of the low-temperature liquid nitrogen pump, so as to achieve the purpose of controlling the output flow rate of the pump. The nitrogen output flow rate of the whole set of equipment is nearly equivalent to the output flow rate of the pump. Thereby achieving the purpose of novel design, reasonable structure and good application effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0013] Figure 1 A process flow chart of a mobile liquid nitrogen pump skid disclosed in an embodiment of the present invention;

[0014] Figure 2 This is an installation layout diagram of a mobile liquid nitrogen pump skid disclosed in an embodiment of the present invention.

[0015] The numbers and letters in the figure represent the corresponding component names:

[0016] 1. Carriage 2. Cryogenic liquid pump 3. Electric control cabinet 5. High-pressure vaporizer 6. High-pressure thermal oil electric heater 61. Fuel tank 62. Heating pipe 7. Generator set 8. Liquid nitrogen inlet pipe 9. Nitrogen outlet pipe 10. Exhaust system heat recovery device 11. Exhaust pipe 12. Liquid nitrogen vent pipe 13. Damper 14. Liquid nitrogen fast inlet pipe 15. Outlet flow meter 16. Monitoring unit DETAILED DESCRIPTION

[0017] 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.

[0018] The present invention is further described in detail below with reference to examples and specific implementation modes.

[0019] Example

[0020] like Figure 1 and Figure 2 As shown, a mobile liquid nitrogen pump skid comprises a cryogenic liquid pump 2, an electric control cabinet 3, a high-pressure vaporizer 5, a high-pressure thermal oil type electric heater 6 and a generator set 7 arranged in a carriage 1; the cryogenic liquid pump 2 is arranged near one side of the rear of the vehicle, and the electric control cabinet 3 is arranged on the other side of the rear of the vehicle, the high-pressure vaporizer 5 is arranged in the middle of the carriage 1, the generator set 7 is arranged near one side of the head of the carriage 1, and the high-pressure thermal oil type electric heater 6 is arranged on the other side of the head of the vehicle, and the high-pressure thermal oil type electric heater 6 comprises an oil tank 61 and a heating pipe 62 arranged in the oil tank;

[0021] One side of the cryogenic liquid pump 2 is first connected to the liquid nitrogen inlet pipe 8, and the other side thereof is connected to the high-pressure vaporizer 5 through the pump liquid outlet pipe. The high-pressure vaporizer 5 is connected to the high-pressure thermal oil type electric heater 6 through a pipeline. The high-pressure thermal oil type electric heater 6 is also connected to the generator set 7. The electric control cabinet 3 is electrically connected to the cryogenic liquid pump 2 and the generator set 7 respectively. A frequency converter is provided in the electric control cabinet 3, and the cryogenic liquid pump 2 is frequency-controlled. The high-pressure thermal oil type electric heater 6 is also connected to the nitrogen outlet pipe 9 and the electric control cabinet circuit respectively, so that the internal nitrogen output pipeline is connected to the nitrogen outlet pipe 9 and the heating pipe 62 is electrically connected to the electric control circuit in the electric control cabinet 3. A smoke exhaust system heat recovery device 10 is provided in the oil tank 61, and the generator set 7 is provided with a smoke exhaust pipe 11, and the smoke exhaust pipe 11 is connected to the smoke exhaust system heat recovery device 10.

[0022] Wherein, the cryogenic liquid pump 2 is also connected to a liquid nitrogen vent pipe 12, and a vent valve is provided on the liquid nitrogen vent pipe 12. A damper 13 is provided on the pump liquid outlet pipe. A liquid nitrogen fast-inlet pipe 14 is also connected to the pump liquid outlet pipe between the damper 13 and the high-pressure vaporizer 5. A safety valve, a pressure gauge and a temperature gauge are also provided on the liquid nitrogen delivery pipeline between the high-pressure vaporizer 5 and the high-pressure thermal oil electric heater 6, and the pressure gauge and the temperature gauge are both connected to the electric control cabinet 3 by electrical signals. An outlet flowmeter 15 is provided on the pipeline between the high-pressure thermal oil electric heater 6 and the nitrogen outlet pipe 9, and the outlet flowmeter 15 is connected to a monitoring unit 16, and the monitoring unit 16 includes a temperature gauge, a pressure gauge and a temperature probe, and the monitoring unit 16 is connected to the electric control cabinet 3 by electrical signals. A safety valve and an outlet pressure gauge are also provided on the liquid nitrogen delivery pipeline between the outlet flowmeter 15 and the high-pressure thermal oil electric heater 6. The liquid nitrogen inlet pipe 8 and the nitrogen outlet pipe 9 are two parallel pipes, and both pipes are provided with stop valves.

[0023] In this example, when the present invention is put into use, nitrogen is input into the system by liquid nitrogen stored in a mobile tank truck, and then pressurized to the required pressure by a low-temperature liquid nitrogen pump, and heated to the required temperature by a liquid nitrogen gasifier. At the same time, the heat recovery device 10 of the exhaust system located in the oil tank 61 is designed to transport and utilize the heat generated by the generator set 7 when it is working through the exhaust pipe 11, thereby reducing heat loss. The gasified nitrogen is output and injected into the pipeline that needs to be purged or pressure tested, and is used to inject nitrogen of a certain pressure into the pipeline that needs to be purged before the use of the oil pipeline, and to perform purging work within a certain pressure range or pressure testing work on the pipeline to meet the needs of pipeline purging or pipeline pressure testing. The adjustment of the nitrogen flow rate is to adjust the output frequency of the frequency converter, thereby adjusting the speed of the low-temperature liquid nitrogen pump, so as to achieve the purpose of controlling the output flow of the pump. The nitrogen output flow rate of the whole set of equipment is nearly equivalent to the output flow rate of the pump. Thus, the purpose of novel design, reasonable structure and good application effect is achieved.

[0024] The output flow rate of the nitrogen system of this mobile liquid nitrogen pump skid can reach 6500-7000L / h. The user can adjust the speed of the low-temperature liquid nitrogen pump by adjusting the output frequency of the frequency converter according to work needs to adjust the pump flow rate. When the nitrogen flow rate exceeds the design flow rate (the flow rate exceeds the gasification capacity of the high-pressure gasifier) ​​or under certain other specific working conditions, when the outlet gas temperature is too low, the temperature probe on the nitrogen outlet pipe 9 will detect the outlet gas temperature at any time. When the temperature is lower than the design value, the temperature probe will transmit the signal to the electric control cabinet 3 to timely interlock the cryogenic liquid pump 2 and stop the continued injection of nitrogen.

[0025] In this system, full-lift safety valves are installed on both high-pressure liquid and gas pipelines, and the tripping pressure of the full-lift safety valves is set at 1.1 times the design pressure. A pressure transmitter is installed at the connection between the high-pressure vaporizer 5 and the high-pressure thermal oil electric heater 6. When the pressure exceeds the set pressure of the transmitter, the pressure transmitter will also interlock the cryogenic liquid pump 2 and stop the operation of the cryogenic liquid pump 2 to ensure that the pressure does not continue to rise rapidly. The set pressure of the pressure transmitter can be set according to the working requirements.

[0026] The above is only a preferred embodiment of the mobile liquid nitrogen pump skid of the present invention. It should be pointed out that, for ordinary technicians in this field, several modifications and improvements can be made without departing from the creative concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A mobile liquid nitrogen pump skid, characterized in that: It includes a low-temperature liquid pump, an electric control cabinet, a high-pressure vaporizer, an oil tank, a high-pressure thermal oil type electric heater and a generator set arranged in the car; the low-temperature liquid pump is arranged near the rear of the car, and the electric control cabinet and the electric control cabinet are arranged on the other side of the rear of the car, the high-pressure vaporizer is arranged in the middle of the car, the generator set is arranged near the head of the car, and the other side of the head of the car is provided with a high-pressure thermal oil type electric heater, and the high-pressure thermal oil type electric heater includes an oil tank and a heating pipe arranged in the oil tank; One side of the cryogenic liquid pump is first connected to the liquid nitrogen inlet pipe, and the other side thereof is connected to the high-pressure vaporizer through the pump liquid outlet pipe. The high-pressure vaporizer is connected to the high-pressure thermal oil type electric heater through a pipeline, and the high-pressure thermal oil type electric heater is also connected to the generator set. The electric control cabinet is electrically connected to the cryogenic liquid pump and the generator set respectively. A frequency converter is provided in the electric control cabinet, and frequency conversion speed regulation is performed on the cryogenic liquid pump; the high-pressure thermal oil type electric heater is also connected to the nitrogen outlet pipe and the electric control cabinet line respectively; a smoke exhaust system heat recovery device is provided in the oil tank, and the generator set is provided with a smoke exhaust pipe, and the smoke exhaust pipe is connected to the smoke exhaust system heat recovery device; The cryogenic liquid pump is also connected to a liquid nitrogen vent pipe, on which a vent valve is provided; a damper is provided on the pump liquid outlet pipe; a liquid nitrogen fast-inlet pipe is also connected to the pump liquid outlet pipe between the damper and the high-pressure vaporizer; A safety valve, a pressure gauge and a temperature gauge are also provided on the liquid nitrogen delivery pipeline between the high-pressure vaporizer and the high-pressure thermal oil electric heater, and the pressure gauge and the temperature gauge are both connected to the electrical signal of the electric control cabinet; An outlet flow meter is provided on the pipeline between the high-pressure thermal oil electric heater and the nitrogen outlet pipe, and the outlet flow meter is connected to a monitoring unit, which includes a temperature gauge, a pressure gauge and a temperature probe, and the monitoring unit is connected to the electric control cabinet by electrical signals; When the temperature is lower than the design value, the temperature probe will transmit the signal to the electric control cabinet to timely interlock the cryogenic liquid pump and stop the continued injection of nitrogen; a pressure transmitter is installed at the connection between the high-pressure vaporizer and the high-pressure thermal oil electric heater. When the pressure exceeds the set pressure of the transmitter, the pressure transmitter will interlock the cryogenic liquid pump and stop the operation of the cryogenic liquid pump.

2. A mobile liquid nitrogen pump skid according to claim 1, characterized in that: A safety valve and an outlet pressure gauge are also provided on the liquid nitrogen delivery pipeline between the outlet flow meter and the high-pressure thermal oil electric heater.

3. A mobile liquid nitrogen pump skid according to claim 2, characterized in that: The liquid nitrogen inlet pipe and the nitrogen outlet pipe are two parallel pipes, and both pipes are provided with stop valves.

Images