Dosage control device for dosing pump at wellhead of oil well

Abstract

The invention discloses a dosing amount control device of an oil well mouth dosing pump. The system comprises a temperature and pressure integrated transmitter, an intelligent control device, a frequency converter, a wellhead dosing pump control cabinet and a wellhead dosing pump, the well mouth dosing pump control cabinet is electrically connected with the temperature and pressure integrated transmitter, the intelligent control device, the frequency converter and the well mouth dosing pump, and the temperature and pressure integrated transmitter is electrically connected with the well mouth dosing pump through the intelligent control device and the frequency converter. The device has the advantages that the pressure and the temperature of crude oil in the oil well gathering pipeline at the wellhead are collected by the temperature and pressure integrated transmitter, the dosage needed in the oil well gathering pipeline is calculated by combining the characteristics of the oil well, and then a signal is transmitted to the wellhead dosing pump through the frequency converter, so that the dosage of the wellhead dosing pump can be accurately controlled; waste of dosage is reduced, and oil well production cost is reduced to the maximum extent. The well mouth dosing pump can be automatically controlled to operate through frequency conversion signals of the frequency converter, manual control is not needed in the whole process, and therefore control accuracy can be improved.

Description

Technical Field

[0001] The invention belongs to the technical field of oil exploitation, and in particular relates to a dosing quantity control device for a dosing pump at an oil wellhead. Background Art

[0002] At present, the commonly used crude oil extraction method is to use a pumping unit to extract crude oil from the pumping well, i.e., the oil well, and then transport it to the metering room in the station through the oil well gathering pipeline. Since crude oil contains substances such as wax and asphalt, these substances will condense on the inner wall of the oil well gathering pipeline as the temperature decreases during the transportation process, which may cause the oil well gathering pipeline to be blocked over time. Therefore, in order to prevent blockage, the usual practice is to add chemicals into the oil well gathering pipeline to prevent these substances from condensing.

[0003] In the related art, a dosing pump installed at the wellhead is usually used to add a fixed frequency and a fixed amount of chemical agents into the oil gathering pipeline of the oil well for anticoagulation. However, although this dosing method can achieve the purpose of ensuring the normal operation of the oil gathering pipeline of the oil well, it does not comprehensively consider the characteristics of each pumping well, and may cause a large waste of chemicals. Summary of the invention

[0004] In order to solve the above problems, the object of the present invention is to provide a dosing quantity control device for a dosing pump at the wellhead of an oil well.

[0005] In order to achieve the above-mentioned purpose, the dosing amount control device of the oil well wellhead dosing pump provided by the present invention includes a temperature and pressure integrated transmitter, an intelligent control device, a frequency converter, a wellhead dosing pump control cabinet and a wellhead dosing pump; wherein, the probe on the temperature and pressure integrated transmitter is tilted and extended into the oil well gathering pipeline located at the wellhead, so as to detect the crude oil temperature and pressure in the oil well gathering pipeline; the wellhead dosing pump control cabinet is electrically connected to the temperature and pressure integrated transmitter, the intelligent control device, the frequency converter and the wellhead dosing pump respectively, and at the same time, the temperature and pressure integrated transmitter is electrically connected to the wellhead dosing pump through the intelligent control device and the frequency converter in turn; the liquid inlet of the wellhead dosing pump is connected to the chemical agent container, and the liquid discharge port is connected to the oil well gathering pipeline located at the wellhead.

[0006] The probe on the temperature and pressure integrated transmitter extends into the middle of the oil gathering pipeline of the oil well.

[0007] The intelligent control device and the frequency converter are installed in the wellhead dosing pump control cabinet.

[0008] The intelligent control device is provided with a data processing controller.

[0009] The wellhead dosing pump control cabinet is provided with a manual and automatic control system, and is also provided with a manual control button and an automatic control button for switching between the two control systems.

[0010] The drug dosage control device for a wellhead drug dosing pump of an oil well provided by the present invention has the following beneficial effects:

[0011] The temperature and pressure integrated transmitter is used to collect the crude oil pressure and temperature in the oil gathering pipeline at the wellhead of the pumping well, and the required dosage in the oil gathering pipeline is calculated in combination with the characteristics of the oil well. Then the frequency converter transmits the signal to the wellhead dosing pump, thereby accurately controlling the dosage of the wellhead dosing pump, reducing the waste of dosing and minimizing the production cost of the oil well. The operation of the wellhead dosing pump can be automatically controlled by using the frequency conversion signal of the frequency converter, and the whole process does not require manual control, thereby improving the accuracy of control. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a block diagram of the drug dosage control device for the oil wellhead drug dosing pump provided by the present invention. DETAILED DESCRIPTION

[0013] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0014] like Figure 1 As shown, the dosing amount control device for the oil well wellhead dosing pump provided by the present invention includes a temperature and pressure integrated transmitter 1, an intelligent control device 2, a frequency converter 3, a wellhead dosing pump control cabinet 4 and a wellhead dosing pump 5; wherein, the probe on the temperature and pressure integrated transmitter 1 is tilted and extended into the oil well gathering pipeline located at the wellhead, so as to detect the crude oil temperature and pressure in the oil well gathering pipeline; the wellhead dosing pump control cabinet 4 is electrically connected to the temperature and pressure integrated transmitter 1, the intelligent control device 2, the frequency converter 3 and the wellhead dosing pump 5 respectively, and at the same time, the temperature and pressure integrated transmitter 1 is electrically connected to the wellhead dosing pump 5 through the intelligent control device 2 and the frequency converter 3 in sequence; the liquid inlet of the wellhead dosing pump 5 is connected to the chemical agent container, and the liquid discharge port is connected to the oil well gathering pipeline located at the wellhead.

[0015] The probe on the temperature and pressure integrated transmitter 1 extends into the middle of the oil gathering pipeline of the oil well.

[0016] The intelligent control device 2 and the frequency converter 3 are installed in a wellhead dosing pump control cabinet 4 .

[0017] The intelligent control device 2 is provided with a data processing controller.

[0018] The wellhead dosing pump control cabinet 4 is provided with a manual and automatic control system, and is also provided with a manual control button and an automatic control button for switching between the two control systems.

[0019] The working principle of the drug dosage control device for the oil well wellhead drug dosing pump provided by the present invention is described as follows:

[0020] Under normal circumstances, an automatic control system is usually used to add chemicals to the oil well gathering pipeline. First, the staff turns on the device and presses the automatic button on the wellhead dosing pump control cabinet 4. Under the control of the automatic control system, the temperature and pressure integrated transmitter 1 is used to detect the temperature and pressure of the crude oil in the oil well gathering pipeline, and then the detection data is sent to the intelligent control device 2. After receiving the above detection data, the intelligent control device 2 uses the data processing controller on it to calculate the dosing amount of the oil well gathering pipeline in combination with the parameters such as the diameter and length of the oil well gathering pipeline pre-entered by the system, the ambient temperature, etc., and then converts the dosing amount into a frequency signal and sends it to the frequency converter 3. Finally, the frequency converter 3 controls the motor speed of the wellhead dosing pump 5, and the wellhead dosing pump 5 accurately adds the chemicals in the chemical container to the oil well gathering pipeline.

[0021] When the automatic control system fails and cannot automatically add chemicals, the staff can press the manual control button to switch to the manual control system and manually control the wellhead dosing pump 5 to add chemicals.

[0022] The method for calculating the dosage of the drug by the data processing controller in the intelligent control device 2 is described as follows:

[0023] First, the total heat transfer coefficient K of the oil well gathering pipeline is calculated according to the operating parameters of the pumping well under stable working conditions. The above operating parameters include: oil well liquid production, liquid specific heat capacity, oil well gathering pipeline outer diameter, oil well gathering pipeline length, wellhead temperature, oil well gathering pipeline end point temperature, oil well gathering pipeline surrounding medium temperature. The calculation formula of the total heat transfer coefficient K is as follows:

[0024]

[0025] Where: K—total heat transfer coefficient; W / (m 2 ℃)

[0026] G—oil well liquid production; kg / s,

[0027] c—Specific heat capacity of liquid; J / (kg·℃)

[0028] D—Outer diameter of oil well gathering pipeline; m

[0029] L—Length of oil well gathering pipeline; m

[0030] T R —Wellhead temperature; ℃

[0031] T Z —Temperature of the end point of the oil gathering pipeline of the oil well; ℃

[0032] T0—The medium temperature around the oil well gathering pipeline; ℃, which is detected by a temperature sensor buried 500-800mm below the ground.

[0033] The data processing controller calculates the precise daily dosage Q of the oil well gathering pipeline based on the above total heat transfer coefficient K. The calculation formula is as follows:

[0034]

[0035] Q—daily dosage; kg

[0036] T E —Ambient temperature; ℃

[0037] T O —The medium temperature around the oil well gathering pipeline; ℃

[0038] K—total heat transfer coefficient;

[0039] P—oil gathering pipeline pressure of oil well; MPa

[0040] e—constant, value is 2.71;

[0041] When the total length of the oil gathering pipeline for the pumping well exceeds 3 km, the daily dosage of the oil gathering pipeline increases by 5.5 kg for every additional km.

[0042] In addition, the outlet pressure value of the wellhead dosing pump 5 is higher than the maximum normal operating pressure value of the pumping well, and its upper limit is 110% of the maximum normal operating pressure value of the pumping well. When the upper limit of the outlet pressure value is reached, the data processing controller will stop the operation of the wellhead dosing pump 5 and alarm.

Claims

1. A dosing quantity control device for a dosing pump at an oil well head, characterized in that: The device for controlling the dosage of a wellhead dosing pump comprises a temperature and pressure integrated transmitter (1), an intelligent control device (2), a frequency converter (3), a wellhead dosing pump control cabinet (4) and a wellhead dosing pump (5); wherein the probe on the temperature and pressure integrated transmitter (1) is inclinedly extended into the oil well gathering pipeline located at the wellhead, and is used to detect the temperature and pressure of the crude oil in the oil well gathering pipeline; the wellhead dosing pump control cabinet (4) is electrically connected to the temperature and pressure integrated transmitter (1), the intelligent control device (2), the frequency converter (3) and the wellhead dosing pump (5) respectively, and the temperature and pressure integrated transmitter (1) is electrically connected to the wellhead dosing pump (5) through the intelligent control device (2) and the frequency converter (3) in sequence; the liquid inlet of the wellhead dosing pump (5) is connected to the chemical agent container, and the liquid outlet is connected to the oil well gathering pipeline located at the wellhead.

2. The device for controlling the amount of medicine added by a medicine-adding pump at the wellhead of an oil well according to claim 1, characterized in that: The probe on the temperature and pressure integrated transmitter (1) extends into the middle of the oil gathering pipeline of the oil well.

3. The device for controlling the amount of medicine added by a medicine-adding pump at the wellhead of an oil well according to claim 1, characterized in that: The intelligent control device (2) and the frequency converter (3) are installed in a wellhead dosing pump control cabinet (4).

4. The device for controlling the amount of medicine added by a medicine-adding pump at the wellhead of an oil well according to claim 1, characterized in that: The intelligent control device (2) is provided with a data processing controller.

5. The device for controlling the amount of medicine added by a medicine-adding pump at the wellhead of an oil well according to claim 1, characterized in that: The wellhead dosing pump control cabinet (4) is provided with a manual control system and an automatic control system, and is also provided with a manual control button and an automatic control button for switching between the two control systems.

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