阅读说明：本技术 一种原油结蜡冷指自动测试装置及其测试方法 (Automatic testing device and testing method for crude oil wax precipitation cold finger ) 是由 付云 张铜耀 尹洪超 陈克 王传军 郑旭 李彪 黄雷 郭秩英 陈韵 辛伟明 来 于 2020-05-26 设计创作，主要内容包括：本发明提供一种原油结蜡冷指自动测试装置,样品筒为双层玻璃筒,外层用于存放加热介质,内层用于存放原油,在样品筒上端口配设盖合筒盖；内筒组件固定设置在筒盖上且悬空置于品筒内部上端,用于置放冷却介质以凝结原油中的蜡形成蜡指；冷却管组件置于内筒组件内,用于对冷却介质进行冷却或升温,从而调节内筒组件壁面温度；搅拌器置于桶盖上并悬空设于样品筒内层,用于搅拌石油；测温系统用于控制样品筒内原油温度和内筒组件结蜡温度；测蜡系统用于实时检测内筒组件外壁上蜡指厚度变化情况。本发明自动测试装置,结构简单且易于控制,自动化程度高,可模拟原油在一定剪切应力和油壁温差下结蜡情况,能够准确检测原油结蜡冷指过程。(The invention provides a crude oil wax precipitation cold finger automatic testing device, wherein a sample cylinder is a double-layer glass cylinder, the outer layer is used for storing a heating medium, the inner layer is used for storing crude oil, and a cylinder cover is matched with the upper port of the sample cylinder; the inner cylinder assembly is fixedly arranged on the cylinder cover and is suspended at the upper end in the product cylinder for placing a cooling medium to condense wax in crude oil to form a wax finger; the cooling pipe assembly is arranged in the inner cylinder assembly and used for cooling or heating a cooling medium so as to adjust the wall surface temperature of the inner cylinder assembly; the stirrer is arranged on the barrel cover and suspended in the inner layer of the sample barrel for stirring petroleum; the temperature measuring system is used for controlling the crude oil temperature in the sample cylinder and the wax precipitation temperature of the inner cylinder assembly; the wax measuring system is used for detecting the thickness change condition of the wax finger on the outer wall of the inner cylinder component in real time. The automatic testing device has the advantages of simple structure, easy control and high automation degree, can simulate the wax precipitation condition of crude oil under a certain shearing stress and oil wall temperature difference, and can accurately detect the wax precipitation cold finger process of the crude oil.)

1. The utility model provides a crude oil wax precipitation cold finger automatic testing arrangement which characterized in that: comprises a sample cylinder (10), an inner cylinder component, a cooling pipe component, a liquid circulator, a stirrer, a temperature measuring system, a wax measuring system, a human-computer interface and a controller; wherein:

the sample cylinder (10) is of a double-layer flat-bottom structure with an upward opening and comprises a sample cylinder outer layer (11), a sample cylinder inner layer (12) and a cylinder cover (15) arranged at an upper port of the sample cylinder (10); the sample cylinder outer layer (11) is used for containing a heating medium, and the sample cylinder inner layer (12) is used for containing a crude oil sample; the outer walls of the upper end part and the lower end part of the sample cylinder (10) are respectively provided with a liquid inlet (13) and a liquid outlet (14) which are respectively connected with an outlet and an inlet of a liquid circulator and are used for forming a circulating oil bath or a circulating water bath in the outer layer (11) of the sample cylinder and heating a crude oil sample in the inner layer (12) of the sample cylinder, so that the temperature of the crude oil sample in the inner layer (12) of the sample cylinder is controlled;

the inner cylinder assembly is arranged on the lower surface of the cylinder cover (15), is suspended at the upper part of the inner layer (12) of the sample cylinder and is used for containing cooling media so as to condense wax in a crude oil sample contained in the inner layer (12) of the sample cylinder on the wall surface of the outer wall of the inner cylinder assembly to form wax fingers;

the cooling pipe assembly is a U-shaped cooling pipe arranged in the inner cylinder assembly, and two ends of the U-shaped cooling pipe penetrate through the cylinder cover (15) and are respectively connected with the outlet and the inlet of the liquid circulator, so that a circulating oil bath or a water bath is formed in the cooling pipe assembly, the cooling medium in the inner cylinder assembly is cooled, and the wall surface temperature of the inner cylinder assembly is adjusted; wherein the temperature of the circulating oil bath or water bath formed in the cooling tube assembly is lower than the temperature of the circulating oil bath or water bath formed in the sample cylinder outer layer (11);

the stirrer is arranged on the cylinder cover (15), suspended in the sample cylinder inner layer (12) and used for stirring a crude oil sample contained in the sample cylinder inner layer (12) to generate a certain shearing stress;

the temperature measuring system comprises temperature sensors which are respectively arranged in the inner layer (12) of the sample cylinder and the inner cylinder component, and the upper ends of the temperature sensors are respectively arranged on the cylinder cover (15) and are used for monitoring the temperature of a crude oil sample contained in the inner layer (12) of the sample cylinder and the temperature of wax fingers on the wall surface of the inner cylinder component in real time;

the wax measuring system comprises a distance measuring sensor arranged on the outer wall of the inner barrel assembly and is used for monitoring the thickness of a wax finger on the outer wall of the inner barrel assembly in real time;

the human-computer interface and the controller are respectively connected with the liquid circulator, the stirrer, the temperature measuring system and the wax measuring system, are connected with the external terminal server, are used for enabling a user to control the working states of the liquid circulator and the stirrer, are used for receiving real-time monitoring data of the temperature measuring system and the wax measuring system, and are used for displaying the data to the user and transmitting the relevant data of the liquid circulator, the stirrer, the temperature measuring system and the wax measuring system to the external terminal server.

2. The automatic testing device for crude oil wax precipitation cold finger of claim 1, characterized in that: the inner cylinder component comprises a first inner cylinder (21) and a second inner cylinder (22) which are symmetrically arranged at two sides of the central axis of the cylinder cover (15); the cooling pipe assembly comprises a first cooling pipe (31) and a second cooling pipe (32) which are respectively arranged inside a first inner barrel (21) and a second inner barrel (22); the temperature sensors of the temperature measuring system are a first temperature sensor (61), a second temperature sensor (62) and a third temperature sensor (63) which are respectively arranged in the inner layer (12) of the sample cylinder, the first inner cylinder (21) and the second inner cylinder (22); the distance measuring sensor of the wax measuring system is a first distance measuring sensor (71) and a second distance measuring sensor (72) which are respectively arranged on the outer walls of the lower end parts of the first inner cylinder (21) and the second inner cylinder (22).

3. The automatic testing device for crude oil wax precipitation cold finger of claim 2, characterized in that: the length of the first inner cylinder (21) is not less than that of the second inner cylinder (22), and the diameters of the outer wall and the inner wall of the first inner cylinder (21) and the second inner cylinder (22) are the same; the sizes of the first cooling pipe (31) and the second cooling pipe (32) are respectively matched with the sizes of the first inner barrel (21) and the second inner barrel (22).

4. The automatic testing device for crude oil wax precipitation cold finger of claim 3, characterized in that: the length of the first inner cylinder (21) is greater than that of the second inner cylinder (22).

5. The automatic testing device for crude oil wax precipitation cold finger of claim 1, characterized in that: a sealing element is arranged between the upper port of the sample cylinder (10) and the cylinder cover (15) and used for ensuring the sealing property of the sample cylinder (10), and the sealing element is a silica gel plane sealing element.

6. The automatic testing device for wax precipitation and cold finger of crude oil according to any one of claims 1 to 5, characterized in that: the agitator includes agitator motor (41), rotation axis (42) and stirring rake (43) from the top down in proper order on the center axis of cover (15), rotation axis (42) run through cover (15), and the upper end of rotation axis (42) is connected with the output of agitator motor (41), and the lower extreme and the stirring rake (43) of rotation axis (42) are connected, stirring rake (43) lower extreme is provided with the paddle, agitator motor (41) are connected with human-computer interface and controller.

7. The automatic testing device for crude oil wax precipitation cold finger of claim 6, characterized in that: and a torque sensor and a speed regulator are arranged on the rotating shaft (42), and the torque sensor and the speed regulator are connected with a human-computer interface and a controller and are used for controlling the torque and the shearing force of the stirrer.

8. The automatic testing device for wax precipitation and cold finger of crude oil according to any one of claims 1 to 5 and 7, characterized in that: the automatic testing device for the crude oil wax precipitation cold finger also comprises a lifting system arranged outside the sample cylinder (10) and used for controlling the opening and closing of the cylinder cover (15); the lifting system comprises a servo motor (51), a rack (52), a transmission screw rod (53) and a connecting arm (54) from top to bottom in sequence, and the output end of the servo motor (51) is connected with the upper end of the transmission screw rod (53); the transmission screw rod (53) penetrates through the rack (52), and the lower end of the transmission screw rod (53) is fixed on the rack (52); the connecting arm (54) is perpendicular to the transmission screw rod (53), one end of the connecting arm (54) is in threaded transmission connection with the transmission screw rod (53) through a nut, and the other end of the connecting arm (54) is fixedly connected with the cylinder cover (15); the human-computer interface and the controller are connected with a servo motor (51) and used for controlling the working state of the lifting system.

9. The automatic testing device for crude oil wax precipitation cold finger of claim 8, characterized in that: the automatic testing device for the crude oil wax precipitation cold finger further comprises a base (80), wherein the sample cylinder (10) and the lifting system are arranged on the base (80) side by side; still be provided with fixed station (90) between lower terminal surface and base (80) of sample cylinder (10), fixed station (90) upper surface is provided with the recess, the shape of recess suits with the shape of sample cylinder (10) lower surface.

10. The testing method of the crude oil wax precipitation cold finger automatic testing device based on any one of claims 1 to 5, 7 and 9 is characterized by comprising the following processes: placing a crude oil sample in an inner layer (12) of a sample cylinder, placing a certain amount of heating medium in an outer layer (11) of the sample cylinder, then respectively connecting a liquid inlet (13) and a liquid outlet (14) with an outlet and an inlet of a liquid circulator, forming a circulating oil bath or a water bath with a certain temperature in the outer layer (11) of the sample cylinder, and controlling the temperature of the crude oil in the inner layer (12) of the sample cylinder through the circulating oil bath or the water bath; placing a certain amount of cooling medium in the inner cylinder assembly, connecting the cooling pipe assembly with an outlet and an inlet of the liquid circulator, forming a circulating oil bath or water bath with a certain temperature in the inner cylinder assembly, and cooling the cooling medium which does not flow in the inner cylinder assembly so as to adjust the temperature of the outer wall of the inner cylinder assembly; starting the stirrer to enable the crude oil sample in the sample cylinder (10) to rotate at a high speed, so that the crude oil sample is subjected to wax precipitation and cold finger under certain shear stress and oil wall temperature difference; in the wax precipitation and cold finger process, the temperature measuring system monitors the temperature of a crude oil sample contained in the inner layer (12) of the sample cylinder and the temperature of wax fingers on the wall surface of the inner cylinder component in real time, the wax measuring system monitors the thickness of the wax fingers on the outer wall of the inner cylinder component in real time, then relevant data are transmitted to the human-computer interface and the controller, and the relevant data of the liquid circulator, the stirrer, the temperature measuring system and the wax measuring system are displayed for a user through the human-computer interface and the controller and are transmitted to the external terminal server.

Technical Field

The invention belongs to the technical field of crude oil wax precipitation testing equipment, and particularly relates to a crude oil wax precipitation cold finger automatic testing device and a testing method thereof.

Background

In the process of crude oil exploitation and pipeline transportation, wax, asphaltene and colloid in the crude oil can be deposited on the pipe wall due to the change of pressure and temperature environmental conditions, so that the transportation resistance of the crude oil is increased. The on-way resistance in the process of pipeline crude oil transportation consists of the frictional resistance between crude oil and wall surfaces and between bulk particles of the crude oil. Under the condition that fluid wets the inner wall of the pipe, no matter the flow state is laminar flow or turbulent flow, a laminar flow boundary layer exists, the maximum flow velocity gradient is concentrated near the pipe wall, and larger shearing force is formed, which is a main source of resistance when crude oil flows in the pipeline. The magnitude of the wall shear force depends on the characteristics of the transported crude oil and the interaction force between the crude oil and the solid wall, and the stronger the attraction force between the pipe wall and the fluid molecules, the greater the frictional resistance loss caused by the wall.

The waxy crude oil is a complex mixed system, which is mainly composed of wax, colloid, aromatic hydrocarbon, asphaltene and light hydrocarbon components. When the temperature is higher, the wax component in the crude oil is in a dissolved state, the crude oil presents Newtonian fluid rheological property, the wax component is gradually crystallized and separated out along with the reduction of the temperature, the viscosity of the crude oil is increased, and the crude oil has the characteristic of non-Newtonian fluid. When the wax crystal precipitation amount reaches 2% -3%, a three-dimensional network structure can be formed to block the flow of crude oil, so that the crude oil loses the fluidity and is solidified.

The wax deposition process brings a series of problems to pipeline transportation of the crude oil containing wax, the effective inner diameter of the pipeline is reduced, the transportation pressure is increased, the pipeline transportation capacity is reduced, the pipeline cleaning frequency is increased, and even wax blockage accidents are caused. And the wax-bearing crude oil transported by the pipeline is easy to change the flow pattern and the flow state under the conditions of low oil outlet temperature and low transportation quantity operation, which can influence the pressure drop of the pipeline and increase the operation cost of the pipeline.

In conclusion, the problem of wax deposition is an important problem affecting the safe, economical and efficient operation of pipelines, so that the research on wax deposition has a significant practical significance for saving the operation cost of the pipelines and ensuring the safe transportation of the pipelines.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides an automatic testing device for crude oil wax precipitation cold fingers.

The invention also aims to provide a testing method based on the crude oil wax precipitation cold finger automatic testing device.

The technical purpose of the invention is realized by the following technical scheme.

An automatic testing device for crude oil wax precipitation cold fingers comprises a sample cylinder, an inner cylinder assembly, a cooling pipe assembly, a liquid circulator, a stirrer, a temperature measuring system, a wax measuring system, a human-computer interface and a controller.

The sample cylinder is of a double-layer flat-bottom structure with an upward opening and comprises a sample cylinder outer layer, a sample cylinder inner layer and a cylinder cover arranged at an upper port of the sample cylinder; the outer layer is used for containing a heating medium, wherein the heating medium can be heat conduction oil or water; the inner layer is used for containing a crude oil sample; the outer walls of the upper end part and the lower end part of the sample cylinder are respectively provided with a liquid inlet and a liquid outlet which are respectively connected with an outlet and an inlet of the liquid circulator and are used for forming a circulating oil bath or a water bath in the outer layer of the sample cylinder and heating the crude oil sample in the inner layer of the sample cylinder so as to control the temperature of the crude oil sample in the inner layer of the sample cylinder; the cylinder cover is made of stainless steel.

The inner cylinder assembly is arranged on the lower surface of the cylinder cover and is suspended above the inner layer of the sample cylinder, and is used for containing a cooling medium so that wax in a crude oil sample contained in the inner layer of the sample cylinder is condensed on the wall surface of the outer wall of the inner cylinder assembly to form a wax finger, and the cooling medium can be water or heat conducting oil.

The cooling pipe assembly is a U-shaped cooling pipe arranged in the inner cylinder assembly, two ends of the U-shaped cooling pipe penetrate through the cylinder cover and are respectively connected with an outlet and an inlet of the liquid circulator, and the cooling pipe assembly is used for forming a circulating oil bath or a water bath in the cooling pipe assembly and cooling a non-flowing cooling medium in the inner cylinder assembly, so that the wall surface temperature of the inner cylinder assembly is adjusted, and then wax emitted by the crude oil sample in the inner layer of the sample cylinder is condensed to form wax fingers. The temperature of the circulating oil bath or water bath formed in the cooling tube assembly is lower than the temperature of the circulating oil bath or water bath formed in the outer layer of the sample cartridge.

The stirrer is arranged on the cylinder cover and suspended in the inner layer of the sample cylinder, and is used for stirring the crude oil sample contained in the inner layer of the sample cylinder to generate certain shear stress.

The temperature measuring system comprises temperature sensors which are respectively arranged in the inner layer of the sample cylinder and the inner cylinder component, wherein the upper ends of the temperature sensors are respectively arranged on the cylinder cover and are used for monitoring the temperature of a crude oil sample contained in the inner layer of the sample cylinder and the wall wax finger temperature of the inner cylinder component in real time.

The wax measuring system comprises a distance measuring sensor arranged on the outer wall of the inner barrel assembly and is used for monitoring the wax finger thickness of the outer wall of the inner barrel assembly in real time.

The human-computer interface and the controller are respectively connected with the liquid circulator, the stirrer, the temperature measuring system and the wax measuring system, are connected with the external terminal server, are used for enabling a user to control the working states of the liquid circulator and the stirrer, are used for receiving real-time monitoring data of the temperature measuring system and the wax measuring system, and are used for displaying the data to the user and transmitting the relevant data of the liquid circulator, the stirrer, the temperature measuring system and the wax measuring system to the external terminal server.

The liquid circulator is a high-precision program-controlled circulating refrigerator and is used for controlling the temperature of crude oil and the temperature of a wax deposition environment so as to simulate the actual wax deposition environment on site, thereby achieving the purpose of controlling the temperature of the oil and the wall surface of the inner cylinder.

Furthermore, the inner cylinder assembly comprises a first inner cylinder and a second inner cylinder which are symmetrically arranged on two sides of the central axis of the cylinder cover, the first inner cylinder and the second inner cylinder are quartz spiral-buckled glass tubes, and can be fixedly placed in the inner layer of the sample cylinder through a special fixture flange to prevent a crude oil sample from being sprayed out in the experimental process; the cooling pipe assembly comprises a first cooling pipe and a second cooling pipe which are respectively arranged in the first inner cylinder and the second inner cylinder, and the first cooling pipe and the second cooling pipe are made of U-shaped seamless spiral pipe materials; the temperature sensors of the temperature measuring system are a first temperature sensor, a second temperature sensor and a third temperature sensor which are respectively arranged in the inner layer of the sample cylinder, the first inner cylinder and the second inner cylinder, and the first temperature sensor, the second temperature sensor and the third temperature sensor are all Pt platinum temperature sensors; the distance measuring sensor of the wax measuring system is a first distance measuring sensor and a second distance measuring sensor which are respectively arranged on the outer walls of the lower end parts of the first inner cylinder and the second inner cylinder.

Furthermore, the length of the first inner cylinder is not less than that of the second inner cylinder, and the diameters of the outer wall and the inner wall of the first inner cylinder and the second inner cylinder are the same; preferably, the length of the first inner cylinder is greater than that of the second inner cylinder; the sizes of the first cooling pipe and the second cooling pipe are respectively matched with the sizes of the first inner cylinder and the second inner cylinder. If only one inner cylinder is arranged, the wax finger is not uniformly solidified due to the limited area of the wall of the inner cylinder, and the device cannot be used once the inner cylinder is damaged and needs to be used after the inner cylinder is replaced again; and two first inner tubes and second inner tubes that the symmetry set up and different length not only can improve the wax and indicate the homogeneity that solidifies, more are favorable to guaranteeing the wax and indicate the stability that solidifies, and the inner tube of co-altitude can collect the wax of wider temperature range and indicate to solidify, is favorable to the research of crude oil wax precipitation. In addition, the first cooling pipe and the second cooling pipe can be set to different temperatures through the liquid circulator, so that the wax with different wax precipitation points in the crude oil sample can be completely precipitated as far as possible and solidified on the outer walls of the first inner cylinder and the second inner cylinder, and the accuracy of a test result is further ensured.

Further, a sealing element is arranged between the upper port of the sample cylinder and the cylinder cover and used for ensuring the sealing performance of the sample cylinder, and the sealing element is a silica gel plane sealing element.

Further, the agitator includes agitator motor, rotation axis and stirring rake from the top down in proper order on the center pin line of cover, the rotation axis runs through the cover, and the upper end of rotation axis is connected with agitator motor's output, and the lower extreme and the stirring rake of rotation axis are connected, the stirring rake lower extreme is provided with the paddle, agitator motor is connected with human-computer interface and controller.

Furthermore, a torque sensor and a speed regulator are arranged on the rotating shaft, and the torque sensor and the speed regulator are connected with the human-computer interface and the controller and used for controlling the torque and the shearing force of the stirrer. The stirrer is mainly used for enabling the stirring paddle to rotate at a high speed, so that the crude oil samples at the outer walls of the first inner cylinder and the second inner cylinder are under a certain shearing strength, and wax deposits are generated on the outer walls of the first inner cylinder and the second inner cylinder and a layer of wax fingers are gradually formed on the outer walls of the first inner cylinder and the second inner cylinder.

Furthermore, the automatic testing device for the wax precipitation cold finger of the crude oil further comprises a lifting system arranged outside the sample cylinder and used for controlling the opening and closing of the cylinder cover; the lifting system comprises a servo motor, a rack, a transmission screw rod and a connecting arm from top to bottom in sequence, and the output end of the servo motor is connected with the upper end of the transmission screw rod; the transmission screw rod penetrates through the rack, and the lower end of the transmission screw rod is fixed on the rack; the connecting arm is perpendicular to the transmission screw rod, one end of the connecting arm is in threaded transmission connection with the transmission screw rod through a nut, and the other end of the connecting arm is fixedly connected with the cylinder cover; the human-computer interface and the controller are connected with the servo motor and used for controlling the working state of the lifting system.

The lifting device comprises a frame, a lifting system, a lifting screw rod, a lifting system and a lifting system, wherein the frame comprises two guide rods which are vertically arranged; one end of the connecting arm is provided with a nut, the nut is sleeved on the outer diameter of the transmission screw rod and can drive the connecting arm to perform thread transmission movement on the transmission screw rod, and the other end of the connecting arm is fixedly connected with the outer edge of the cylinder cover in a welding manner; after the lifting system is powered on, the switch is turned on, the servo motor starts to work, the transmission screw rod is driven by the servo motor to rotate in the positive and negative directions, and the transmission screw rod drives the nut on the connecting arm to move up and down, so that the barrel cover is controlled to lift, and the opening and the closing of the sample barrel are automatically controlled.

Further, inlet and drain outlet dislocation set up on the lateral wall of sample section of thick bamboo and stagger the setting with operating system, and the purpose is when filling or discharge the heating medium in the sample section of thick bamboo skin, and operating space is big, mutually independent and each other do not influence the operation, also do not interfered by operating system's position simultaneously.

Further, the automatic testing device for the wax precipitation cold finger of the crude oil further comprises a base, wherein the sample cylinder and the lifting system are arranged on the base side by side; still be provided with the fixed station between the lower terminal surface of sample cylinder and the base, the fixed station upper surface is provided with the recess, the shape of recess suits with the shape of sample cylinder lower surface for fixed sample cylinder prevents its activity, influences the wax finger and solidifies.

The crude oil wax precipitation cold finger automatic testing device can obtain the following relevant parameters of a crude oil sample: in the testing process, the temperature of a crude oil sample, the temperature of the first inner cylinder (namely, the first cold finger temperature at which wax finger solidification occurs on the outer wall of the first inner cylinder), the temperature of the second inner cylinder (namely, the second cold finger temperature at which wax finger solidification occurs on the outer wall of the second inner cylinder), the wax finger thickness of the outer wall of the first inner cylinder (namely, the first wax finger thickness), the wax finger thickness of the outer wall of the second inner cylinder (namely, the second wax finger thickness), the torque data of a stirrer, the testing time (namely, the wax precipitation cold finger time) and the like are further calculated, and the data such as the wax precipitation rate and the like are further calculated, and then the wax deposition condition in the crude oil is comprehensively evaluated by combining with other subsequent testing processes.

The testing method based on the crude oil wax precipitation cold finger automatic testing device comprises the following steps of:

placing a crude oil sample in the inner layer of the sample cylinder, placing a certain amount of heating medium in the outer layer of the sample cylinder, then respectively connecting the liquid inlet and the liquid outlet with the outlet and the inlet of the liquid circulator, forming a circulating oil bath or a water bath with a certain temperature in the outer layer of the sample cylinder, and controlling the temperature of the crude oil in the inner layer of the sample cylinder through the circulating oil bath or the water bath; placing a certain amount of cooling medium in the inner cylinder assembly, connecting the cooling pipe assembly with an outlet and an inlet of the liquid circulator, forming a circulating oil bath or water bath with a certain temperature in the inner cylinder assembly, and cooling the cooling medium which does not flow in the inner cylinder assembly so as to adjust the temperature of the outer wall of the inner cylinder assembly; starting the stirrer to enable the crude oil sample in the sample cylinder to rotate at a high speed, and enabling the crude oil sample to carry out wax precipitation and cold finger under certain shearing stress and oil wall temperature difference; in the process of wax precipitation and cold finger, the temperature measuring system monitors the temperature of a crude oil sample contained in the inner layer of the sample cylinder and the temperature of wax fingers on the wall surface of the inner cylinder component in real time, the wax measuring system monitors the thickness of the wax fingers on the outer wall of the inner cylinder component in real time, then relevant data are transmitted to the human-computer interface and the controller, and the relevant data of the liquid circulator, the stirrer, the temperature measuring system and the wax measuring system are displayed for a user through the human-computer interface and the controller and are transmitted to the external terminal server.

Compared with the prior art, the automatic testing device for the crude oil wax precipitation cold finger has the advantages of simple structure, easy control and high automation degree, can simulate the wax precipitation condition of crude oil under a certain shearing stress and oil wall temperature difference, can automatically detect the crude oil wax precipitation cold finger process, can more accurately know the influence of the inner cylinder wax precipitation wall surface temperature on wax deposition, and has obvious practical significance in the field of pipeline safe transportation of wax-containing crude oil.

Drawings

FIG. 1 is a perspective view of an automatic testing device for wax precipitation and cold finger of crude oil according to the present invention;

FIG. 2 is a cross-sectional view of an automatic testing device for wax precipitation and cold finger of crude oil according to the present invention;

FIG. 3 is a top view of the automatic testing device for wax precipitation and cold finger of crude oil according to the present invention;

reference numerals:

10-a sample cylinder, 11-a sample cylinder outer layer, 12-a sample cylinder inner layer, 13-a liquid inlet, 14-a liquid outlet, 15-a cylinder cover, 21-a first inner cylinder, 22-a second inner cylinder, 31-a first cooling pipe, 32-a second cooling pipe, 41-a stirring motor, 42-a rotating shaft, 43-a stirring paddle, 51-a servo motor, 52-a rack, 53-a transmission screw rod, 54-a connecting arm, 61-a first temperature sensor, 62-a second temperature sensor, 63-a third temperature sensor, 71-a first distance measuring sensor, 72-a second distance measuring sensor, 80-a base, 90-a fixed table, 101-a first liquid circulator, 102-a second liquid circulator and 103-a third liquid circulator.

Detailed Description

The invention is described in further detail below with reference to the figures and specific examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Referring to fig. 1 to 3, the present invention provides an automatic testing apparatus for crude oil wax deposition cold finger, which comprises a sample cylinder 10, an inner cylinder assembly, a cooling tube assembly, a liquid circulator, a stirrer, a temperature measuring system, a wax measuring system, a human-computer interface and controller (not shown), and a base 80.

The human-computer interface and the controller are respectively connected with the liquid circulator, the stirrer, the temperature measuring system and the wax measuring system, are connected with the external terminal server, are used for enabling a user to control the working states of the liquid circulator and the stirrer, are used for receiving real-time monitoring data of the temperature measuring system and the wax measuring system, and are used for displaying the data to the user and transmitting the relevant data of the liquid circulator, the stirrer, the temperature measuring system and the wax measuring system to the external terminal server.

The liquid circulators are 3 high-precision program-controlled circulating refrigerators, namely a first liquid circulator 101, a second liquid circulator 102 and a third liquid circulator 103, and are used for controlling the crude oil temperature and the wax deposition environment temperature so as to simulate the actual wax deposition environment on site and further achieve the purpose of controlling the temperature of the oil temperature and the wall surface of the inner cylinder. Wherein, the temperature control range is as follows: 0-200 ℃, the heating rate is 3 ℃/min, the temperature control precision is +/-1 ℃, and the temperature display precision is as follows: . + -. 0.1 ℃. The temperature controller is controlled by a microcomputer PID, the overheating protection sensor is a K-type thermocouple, and the heater is a K-type thermocouple.

The sample cylinder 10 is of a double-layer flat-bottom structure with an upward opening and comprises a sample cylinder outer layer 11, a sample cylinder inner layer 12 liquid inlet 13, a liquid outlet 14 and a cylinder cover 15 arranged at an upper port of the sample cylinder 10; the outer layer 11 is used for containing a heating medium, wherein the heating medium is heat conduction oil; the inner layer 12 is used for containing a crude oil sample; the liquid inlet 13 and the liquid outlet 14 are respectively arranged on the outer walls of the upper end part and the lower end part of the sample cylinder 10, are respectively connected with the outlet and the inlet of the first liquid circulator 101, and are used for forming a circulating oil bath in the outer layer 11 of the sample cylinder and heating the crude oil sample in the inner layer 12 of the sample cylinder so as to control the temperature of the crude oil sample in the inner layer 12 of the sample cylinder; the cylinder cover 15 is made of stainless steel, and a silica gel plane sealing element is arranged between the cylinder cover 15 and the upper port of the sample cylinder 10 and used for ensuring the sealing performance of the sample cylinder 10. The liquid inlet 13 and the liquid outlet 14 are arranged on the outer side wall of the sample cylinder 10 in a staggered manner and are arranged in a staggered manner with the lifting system, so that when a heating medium is filled or discharged, the operation space is large, the operation is independent from each other and does not influence each other, and meanwhile, the position of the lifting system does not interfere with each other. The sample cartridge 10 may be sized as desired and is not particularly limited herein.

The inner cylinder assembly comprises a first inner cylinder 21 and a second inner cylinder 22 which are symmetrically arranged on two sides of the central axis of the cylinder cover 15 and are used for containing a cooling medium so that wax in a crude oil sample contained in the inner layer 12 of the sample cylinder is condensed on the wall surface of the outer wall of the inner cylinder assembly to form a wax finger, and the cooling medium is heat conduction oil; the first inner cylinder 21 and the second inner cylinder 22 both adopt quartz spiral-buckled glass tubes, and the upper ends of the quartz spiral-buckled glass tubes are both arranged on the lower surface of the cylinder cover 15 and are suspended on the upper part of the inner layer 12 of the sample cylinder; the first inner cylinder 21 and the second inner cylinder 22 are fixedly arranged in the sample cylinder inner layer 12 through special fixture flanges, so that the crude oil sample is prevented from being sprayed out in the experiment process, the fixture flanges can be set according to actual needs, and are not particularly limited and are not described in detail. The length of the first inner cylinder 21 is greater than that of the second inner cylinder 22, and the diameters of the outer wall and the inner wall of the first inner cylinder 21 and the second inner cylinder 22 are the same. If only one inner cylinder is arranged, the wax finger is not uniformly solidified due to the limited area of the wall of the inner cylinder, and the device cannot be used once the inner cylinder is damaged and needs to be used after the inner cylinder is replaced again; the two first inner cylinders 21 and the second inner cylinders 22 which are symmetrically arranged and have different lengths can improve the solidification uniformity of the wax fingers and be more favorable for ensuring the solidification stability of the wax fingers, and the inner cylinders with different heights can collect the wax fingers with wider temperature range to be solidified, so that the research on crude oil wax precipitation is facilitated.

The cooling pipe assembly comprises a first cooling pipe 31 and a second cooling pipe 32 which are respectively arranged in the first inner cylinder 21 and the second inner cylinder 22, the first cooling pipe 31 and the second cooling pipe 32 are both U-shaped seamless spiral pipes, and two ends of each U-shaped seamless spiral pipe penetrate through the cylinder cover 15; the two ends of the first cooling pipe 31 are respectively connected with the outlet and the inlet of the second liquid circulator 102, the two ends of the second cooling pipe 32 are respectively connected with the outlet and the inlet of the third liquid circulator 103, and the second cooling pipe is used for respectively forming a circulating oil bath in the first inner cylinder 21 and the second inner cylinder 22 and respectively cooling the non-flowing cooling medium in the first inner cylinder 21 and the second inner cylinder 22, so that the wall surface temperatures of the first inner cylinder 21 and the second inner cylinder 22 are respectively adjusted, and further, the wax emitted from the crude oil sample in the sample cylinder inner layer 12 is condensed and solidified to form a wax finger; wherein the temperatures of the first cooling pipe 31 and the second cooling pipe 32 are adjusted to 30 ℃ and 25 ℃ by the second liquid circulator 102 and the third liquid circulator 103, respectively. The sizes of the first cooling pipe 31 and the second cooling pipe 32 are matched with the sizes of the first inner barrel 21 and the second inner barrel 22 respectively. In this embodiment, the first cooling pipe 31 and the second cooling pipe 32 are both made of U-shaped seamless spiral pipe material; the first inner cylinder 21 has a dimension D35 x 150mm and a wall thickness of about 2 mm; the second inner barrel 22 has a dimension D35 x 100mm and a wall thickness of about 2 mm; accordingly, the first cooling tube 31 is sized D15 × 600mm, and the second cooling tube 32 is sized D15 × 400 mm.

The stirrer is arranged on the central axis of the cylinder cover 15 and is suspended in the sample cylinder inner layer 12, and is used for stirring the crude oil sample contained in the sample cylinder inner layer 12 to generate certain shearing stress. The agitator from the top down includes agitator motor 41, rotation axis 42 and stirring rake 43 in proper order, agitator motor 41 is connected with human-computer interface and controller, rotation axis 42 runs through cover 15, and the upper end of rotation axis 42 is connected with agitator motor 41's output, and rotation axis 42's lower extreme is connected with stirring rake 43, stirring rake 43 lower extreme is provided with the paddle, and the shearing force accessible human-computer interface and the controller of paddle carry out parameter setting to the wax crystallization. In this embodiment, the stirring motor 41 is a motor with power of AC220V, 2.2KW, 2880 r/min; the rotating shaft 42 is provided with a torque sensor (not shown in the figure) and a speed regulator (not shown in the figure), the torque sensor and the speed regulator are both connected with a human-computer interface and a controller and are used for controlling the torque and the shearing force of the stirrer, the measuring range of the torque sensor is +/-100 mNm, the measuring precision is +/-0.1 mNm, and the rotating speed regulating range of the speed regulator is 0-80r/min, so that the requirement can be met. The stirrer is mainly used for generating high-speed rotation of the stirring paddle 43, so that the crude oil sample at the outer walls of the first inner cylinder 21 and the second inner cylinder 22 is under a certain shearing strength, and wax deposition is generated on the outer walls of the first inner cylinder 21 and the second inner cylinder 22 and a layer of wax fingers are gradually formed on the outer walls.

The lifting system is arranged outside the sample cylinder 10 and used for controlling the opening and closing of the cylinder cover 15; the lifting system comprises a servo motor 51, a rack 52, a transmission screw rod 53 and a connecting arm 54 from top to bottom in sequence, wherein the output end of the servo motor 51 is connected with the upper end of the transmission screw rod 53; the transmission screw 53 penetrates through the frame 52, and the lower end of the transmission screw 53 is fixed on the frame 52. The machine frame 52 comprises two guide rods which are vertically arranged, a sleeve head is arranged at the upper end of each guide rod, the lower ends of the guide rods are fixed on a table top of a cuboid, the table top is used for supporting and fixing the whole lifting system, a reinforcing plate is further arranged between the sleeve head and the table top, the reinforcing plate is arranged at the lower end of each guide rod, and the lower end of the transmission screw rod 53 penetrates through the central positions of the sleeve head and the reinforcing plate and is fixedly and rotatably connected with the sleeve head and the reinforcing plate through threads. One end of the connecting arm 54 is provided with a nut which is sleeved on the outer diameter of the transmission screw rod 53 and can drive the connecting arm 54 to perform thread transmission movement on the transmission screw rod 53, the other end of the connecting arm 54 is fixedly connected with the outer edge of the cylinder cover 15 in a welding manner, and the connecting arm 54 is arranged perpendicular to the transmission screw rod 53. The human-machine interface and controller is connected with a servo motor 51 and is used for controlling the working state of the lifting system. After the lifting system is powered on, the switch is turned on, the servo motor 51 starts to work, the servo motor 51 drives the transmission screw rod 53 to rotate in the forward and reverse directions, and the transmission screw rod 53 drives the nut on the connecting arm 54 to move up and down, so that the barrel cover 15 is controlled to lift, and the opening and the closing of the sample barrel 10 are automatically controlled.

The temperature measurement system comprises temperature sensors which are respectively arranged in the inner layer 12 of the sample cylinder and the inner cylinder component, and the upper ends of the temperature sensors are respectively arranged on the cylinder cover 15 and are used for monitoring the temperature of a crude oil sample contained in the inner layer 12 of the sample cylinder and the temperature of the wax finger on the wall surface of the inner cylinder component in real time. The temperature measuring system comprises a first temperature sensor 61, a second temperature sensor 62 and a third temperature sensor 63 which are respectively arranged in the inner layer 12 of the sample cylinder, the first inner cylinder 21 and the second inner cylinder 22, the upper ends of the three temperature sensors are fixedly arranged on the cylinder cover 15 and are respectively used for controlling the temperature of a crude oil sample contained in the inner layer 12 of the sample cylinder and the wax finger temperature on the wall surfaces of the first inner cylinder group 21 and the second inner cylinder 22; the first temperature sensor 61, the second temperature sensor 62 and the third temperature sensor 63 are all Pt platinum temperature sensors.

The wax measuring system comprises a first distance measuring sensor 71 and a second distance measuring sensor 72 which are respectively arranged on the outer walls of the lower ends of the first inner cylinder 21 and the second inner cylinder 22 and are used for monitoring the wax finger thickness of the outer walls of the first inner cylinder group 21 and the second inner cylinder 22 in real time. In the present embodiment, the first distance measuring sensor 71 and the second distance measuring sensor 72 are both of model LJ-G200.

The base 80 is arranged below the sample cylinder 10, and the sample cylinder 10 and the lifting system are arranged on the base 80 side by side; still be provided with fixed station 90 between the lower terminal surface of sample cylinder 10 and the base 80, fixed station 90 upper surface is provided with the recess, the shape of recess suits with the shape of sample cylinder 10 lower surface for fixed sample cylinder 10 prevents its activity, influences the wax finger and solidifies.

The testing method based on the crude oil wax precipitation cold finger automatic testing device comprises the following steps of:

placing a crude oil sample in the inner layer 12 of the sample cylinder, placing a certain amount of heat conduction oil in the outer layer 11 of the sample cylinder, then respectively connecting the liquid inlet 13 and the liquid outlet 14 with the outlet and the inlet of the first liquid circulator 101, forming a circulating oil bath with a certain temperature on the outer layer 11 of the sample cylinder, and controlling the temperature of the crude oil in the inner layer 12 of the sample cylinder through the circulating oil bath; respectively placing a certain amount of heat conduction oil in the first inner cylinder 21 and the second inner cylinder 22, respectively connecting two ends of the first cooling pipe 31 with an outlet and an inlet of the second liquid circulator 102, respectively connecting two ends of the second cooling pipe 32 with an outlet and an inlet of the third liquid circulator 103, respectively forming a circulating oil bath with a certain temperature in the first inner cylinder 21 and the second inner cylinder 22 (wherein the temperature of the circulating oil bath formed in the second cooling pipe 32 is lower than that of the circulating oil bath formed in the first cooling pipe 31 and lower than that of the circulating oil bath formed in the sample cylinder outer layer 11), respectively cooling the heat conduction oil which does not flow in the first inner cylinder 21 and the second inner cylinder 22, and further adjusting the temperature of the outer walls of the first inner cylinder 21 and the second inner cylinder 22; starting the stirrer to enable the crude oil sample in the sample cylinder 10 to rotate at a high speed, and enabling the crude oil sample to carry out wax precipitation and cold finger under certain shearing stress and oil wall temperature difference; a user regulates and controls the temperature of the liquid circulator, the rotating speed and the torque of the stirrer and the like through a human-computer interface and a controller; the human-computer interface and the controller receive the temperature of a crude oil sample, the temperature of the first inner cylinder (namely, the first cold finger temperature at which wax fingers are solidified on the outer wall of the first inner cylinder) and the temperature of the second inner cylinder (namely, the second cold finger temperature at which wax fingers are solidified on the outer wall of the second inner cylinder) in the testing process, which are measured in real time by the temperature measuring system, and receive the wax finger thickness (namely, the first wax finger thickness) of the outer wall of the first inner cylinder and the wax finger thickness (namely, the second wax finger thickness) of the outer wall of the second inner cylinder, which are measured in real time by the wax measuring system; meanwhile, the human-computer interface and the controller display the data to a user and transmit the data, the torque data of the stirrer, the test time (namely wax deposition cold finger time) and the like to the external terminal server, and carry out real-time analysis through related detection software in the external terminal server, so that the influence of the actual shearing stress value on the wax deposition of the crude oil is accurately reflected, the influence of the wax deposition wall surface temperature on the wax deposition is more accurately known, the wax deposition rate and other data are calculated, and then the wax deposition condition in the crude oil is comprehensively evaluated in combination with other subsequent test processes; in addition, the wax precipitation rate and other data are calculated, and then the wax deposition condition in the crude oil is comprehensively evaluated by combining with other subsequent testing processes.

The device has the characteristics of simple structure, easy control and high automation degree, can simulate the wax precipitation condition of crude oil under certain shearing stress and oil wall temperature difference, can automatically detect the wax precipitation cold finger process of the crude oil, and can more accurately know the influence of the wax precipitation wall surface temperature of the inner cylinder on wax deposition.

Although the methods and techniques of the present invention have been described in terms of preferred embodiments, it will be apparent to those of ordinary skill in the art that variations and/or rearrangements of the methods and techniques described herein may be made without departing from the spirit and scope of the invention. It is expressly intended that all such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope and content of the invention.