Oil well heating cable energy consumption control method

Abstract

The invention relates to an oil well electric heating cable energy consumption control method which comprises the steps that relevant parameters of each oil well are collected, and the relevant parameters comprise the crude oil freezing point, the crude oil wax precipitation temperature, the ground temperature gradient, the wellhead output liquid temperature and the crude oil viscosity-temperature curve; and controlling the operation of the electric heating cable according to the relevant parameters of each oil well. The invention aims to provide the method for controlling the energy consumption of the electric heating cable of the oil well aiming at the practical problems in the production process of heating the oil well by virtue of the cable. The temperature of output liquid of a wellhead is determined; the operation time and parameters of the electric heating cable are determined; the heat efficiency of the electric heating cable is fully exerted; the normal lifting of crude oil in an oil pipe is ensured, the polished rod load of a pumping unit is reduced, the normal production of an oil well is ensured, and the energy consumption of the electric heating cable is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of oil production, and in particular to an energy consumption control method for an oil well heating cable. Background Art

[0002] During the production process of oil wells, high-freezing point crude oil has a high freezing point and high viscosity at low temperatures, which increases the load on the pumping unit suspension point and easily causes the pumping unit to get stuck. If the wellbore heating technology is not adopted in some wells, the oil wells cannot be produced normally. The problem of oil well lifting is solved by lowering electric heating hollow rods or heating cables into the oil wells to achieve normal production of the oil wells. However, in the actual production process, in order to ensure the normal production of the oil wells, the wellhead temperature, electric heating cable depth and heating time are usually set based on experience, which leads to excessive electric heating energy consumption, and the electric heating cable is prone to short circuit and short life. If the wellhead temperature is too low and the electric heating depth is too shallow, the oil well load is too large and cannot be produced normally. Summary of the invention

[0003] The object of the present invention is to provide an oil well heating cable energy consumption control method to improve the above-mentioned problem.

[0004] The present invention provides an energy consumption control method for an oil well electric heating cable, comprising:

[0005] Collect relevant parameters of each oil well, including crude oil solidification point, crude oil wax precipitation temperature, geothermal gradient, wellhead output fluid temperature and crude oil viscosity-temperature curve;

[0006] The operation of the electric heating cable is controlled according to the relevant parameters of each oil well.

[0007] Optionally, the method used for the electric heating cable is a constant power control method, and the power value of the electric heating cable is determined by the constant power control method.

[0008] Optionally, the electric heating cable comprises an electric heating hollow rod or a heating cable.

[0009] Optionally, the heating cable is cylindrical in shape with a diameter of 16 + 1mm.

[0010] Optionally, the formation temperature at the depth where the electric heating cable is lowered into the well is determined according to the geothermal gradient, and when the formation temperature at the depth where the electric heating cable is lowered into the well is greater than or equal to the wax precipitation temperature of the crude oil, high-temperature wax dissolution is performed through the electric heating cable.

[0011] Optionally, controlling the operation of the electric heating cable according to the relevant parameters of each oil well includes:

[0012] Obtain the wax content of each oil well;

[0013] For oil wells with wax content less than 12%, the wellhead temperature is raised to 10°C above the wax precipitation temperature of crude oil by relying on the electric heating cable every 20-30 days. For oil wells with wax content greater than 18%, the wellhead temperature is raised to 12°C above the wax precipitation temperature of crude oil by relying on the electric heating cable every 10-15 days. The wax melting time is 2 hours to achieve the purpose of dissolving wax.

[0014] Optionally, controlling the operation of the electric heating cable according to the relevant parameters of each oil well includes:

[0015] For each oil well, when the temperature of the produced liquid at the wellhead is 5°C lower than the freezing point of crude oil, the ground electric heating control cabinet is used to control the electric heating cable to start running; when the temperature of the produced liquid at the wellhead is more than 5°C higher than the freezing point of crude oil, the ground electric heating control cabinet is used to control the electric heating cable to stop running.

[0016] Optionally, controlling the operation of the electric heating cable according to the relevant parameters of each oil well includes:

[0017] For each oil well, based on the crude oil viscosity-temperature curve, when the crude oil viscosity corresponding to the wellhead output liquid temperature is less than or equal to 50 mPas, the electric heating control cabinet is used to control the electric heating cable to stop running.

[0018] The beneficial effects of the present invention are:

[0019] 1. The purpose of the present invention is to provide a method for controlling energy consumption of electric heating cables in oil wells in response to the practical problems in the production process of oil wells that rely on cable heating. Determine the length of the electric heating cable in the well, determine the temperature of the wellhead output liquid, determine the operating time and parameters of the electric heating cable, give full play to the thermal efficiency of the electric heating cable, ensure the normal lifting of crude oil in the oil pipe, reduce the load on the suspension point of the pumping unit, ensure the normal production of the oil well, and reduce the energy consumption of the electric heating cable.

[0020] 2. The purpose of the present invention is to provide a method for controlling energy consumption of electric heating cables in oil wells for heating crude oil with high freezing point and high wax content during production, using electric heating hollow rods or heating cables (hereinafter referred to as heating cables) to produce crude oil. First, relevant parameters such as the freezing point, wax precipitation point, and geothermal gradient of crude oil are collected; the outlet temperature of the wellhead is collected, and the wellhead heating temperature, heating time, and periodic wax dissolution temperature are controlled by a ground electric heating control cabinet; the depth of the electric heating cable is designed according to the freezing point and wax precipitation point of the crude oil. By optimizing the electric heating power, heating time, and wellhead temperature, the ground system adopts a heating furnace or a water mixing system to reduce the power consumption of the wellbore heating cable, solve the problem of excessive electric heating energy consumption and wax deposition in the oil well during crude oil production, and realize a production method without hot washing and adding chemicals, thereby reducing the labor intensity of employees.

[0021] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or be understood by implementing the embodiments of the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 This is the viscosity-temperature curve of crude oil from a well in Xinghua Block 1. DETAILED DESCRIPTION

[0024] Example 1

[0025] A method for controlling energy consumption of an oil well electric heating cable, comprising:

[0026] Collect relevant parameters of each oil well, including crude oil solidification point, crude oil wax precipitation temperature, geothermal gradient, wellhead output fluid temperature and crude oil viscosity-temperature curve;

[0027] The operation of the electric heating cable is controlled according to the relevant parameters of each oil well. The method used for the heating cable is a constant power control method, and the power value of the electric heating cable is determined by the constant power control method, that is, the power value of the heating cable of the well is determined according to the liquid production and water content. The electric heating cable is an electric heating hollow rod.

[0028] The formation temperature at the depth of the well where the electric heating cable is lowered is determined according to the geothermal gradient. When the formation temperature at the depth of the well where the electric heating cable is lowered is greater than or equal to the wax precipitation temperature of the crude oil, high-temperature wax dissolution is performed through the electric heating cable.

[0029] Obtain the wax content of each oil well; for oil wells with a wax content of less than 12%, every 20 days, the wellhead temperature is increased to 10°C above the wax precipitation temperature of crude oil by relying on the electric heating cable; for oil wells with a wax content of more than 18%, every 10 days, the wellhead temperature is increased to 12°C above the wax precipitation temperature of crude oil by relying on the electric heating cable, and the wax melting time is 2 hours to achieve the purpose of dissolving wax.

[0030] For each oil well, when the temperature of the produced liquid at the wellhead is 5°C lower than the freezing point of crude oil, the ground electric heating control cabinet is used to control the electric heating cable to start running; when the temperature of the produced liquid at the wellhead is more than 5°C higher than the freezing point of crude oil, the ground electric heating control cabinet is used to control the electric heating cable to stop running.

[0031] For each oil well, based on the crude oil viscosity-temperature curve, when the crude oil viscosity corresponding to the wellhead output liquid temperature is less than or equal to 50 mPas, the electric heating control cabinet is used to control the electric heating cable to stop running.

[0032] Example 2

[0033] A method for controlling energy consumption of an oil well electric heating cable, comprising:

[0034] Collect relevant parameters of each oil well, including crude oil solidification point, crude oil wax precipitation temperature, geothermal gradient, wellhead output fluid temperature and crude oil viscosity-temperature curve;

[0035] The operation of the electric heating cable is controlled according to the relevant parameters of each oil well. The method used for the heating cable is the constant power control method, and the power value of the electric heating cable is determined by the constant power control method, that is, the power value of the heating cable of the well is determined according to the liquid production and water content. The electric heating cable is a heating cable, and the heating cable is cylindrical with a diameter of 16mm, so that it can be put into the electric heating rod after the oil well stops spraying.

[0036] The formation temperature at the depth of the well where the electric heating cable is lowered is determined according to the geothermal gradient. When the formation temperature at the depth of the well where the electric heating cable is lowered is greater than or equal to the wax precipitation temperature of the crude oil, high-temperature wax dissolution is performed through the electric heating cable.

[0037] Obtain the wax content of each oil well; for oil wells with a wax content of less than 12%, every 20 days, the wellhead temperature is increased to 10°C above the wax precipitation temperature of crude oil by relying on the electric heating cable; for oil wells with a wax content of more than 18%, every 10 days, the wellhead temperature is increased to 12°C above the wax precipitation temperature of crude oil by relying on the electric heating cable, and the wax melting time is 2 hours to achieve the purpose of dissolving wax.

[0038] For each oil well, when the temperature of the produced liquid at the wellhead is 5°C lower than the freezing point of crude oil, the ground electric heating control cabinet is used to control the electric heating cable to start running; when the temperature of the produced liquid at the wellhead is more than 5°C higher than the freezing point of crude oil, the ground electric heating control cabinet is used to control the electric heating cable to stop running.

[0039] For each oil well, based on the crude oil viscosity-temperature curve, when the crude oil viscosity corresponding to the wellhead output liquid temperature is less than or equal to 50 mPas, the electric heating control cabinet is used to control the electric heating cable to stop running.

[0040] Example 3

[0041] A method for controlling energy consumption of an oil well electric heating cable, comprising:

[0042] Collect relevant parameters of each oil well, including crude oil solidification point, crude oil wax precipitation temperature, geothermal gradient, wellhead output fluid temperature and crude oil viscosity-temperature curve;

[0043] The operation of the electric heating cable is controlled according to the relevant parameters of each oil well. The method used for the heating cable is the constant power control method, and the power value of the electric heating cable is determined by the constant power control method, that is, the power value of the heating cable of the well is determined according to the liquid production and water content. The electric heating cable is a heating cable, and the heating cable is cylindrical with a diameter of 17mm, which is convenient for lowering into the electric heating rod after the oil well stops spraying.

[0044] The formation temperature at the depth of the well where the electric heating cable is lowered is determined according to the geothermal gradient. When the formation temperature at the depth of the well where the electric heating cable is lowered is greater than or equal to the wax precipitation temperature of the crude oil, high-temperature wax dissolution is performed through the electric heating cable.

[0045] Obtain the wax content of each oil well; for oil wells with a wax content of less than 12%, every 25 days, the wellhead temperature is increased to 10°C above the wax precipitation temperature of crude oil by relying on the electric heating cable; for oil wells with a wax content of more than 18%, every 13 days, the wellhead temperature is increased to 12°C above the wax precipitation temperature of crude oil by relying on the electric heating cable, and the wax melting time is 2 hours to achieve the purpose of dissolving wax.

[0046] For each oil well, when the temperature of the produced liquid at the wellhead is 5°C lower than the freezing point of crude oil, the ground electric heating control cabinet is used to control the electric heating cable to start running; when the temperature of the produced liquid at the wellhead is more than 5°C higher than the freezing point of crude oil, the ground electric heating control cabinet is used to control the electric heating cable to stop running.

[0047] For each oil well, based on the crude oil viscosity-temperature curve, when the crude oil viscosity corresponding to the wellhead output liquid temperature is less than or equal to 50 mPas, the electric heating control cabinet is used to control the electric heating cable to stop running.

[0048] Example 4

[0049] A method for controlling energy consumption of an oil well electric heating cable, comprising:

[0050] Collect relevant parameters of each oil well, including crude oil solidification point, crude oil wax precipitation temperature, geothermal gradient, wellhead output fluid temperature and crude oil viscosity-temperature curve;

[0051] The operation of the electric heating cable is controlled according to the relevant parameters of each oil well. The method used for the heating cable is the constant power control method, and the power value of the electric heating cable is determined by the constant power control method, that is, the power value of the heating cable of the well is determined according to the liquid production and water content. The electric heating cable is a heating cable, and the heating cable is cylindrical with a diameter of 15mm, so that it can be put into the electric heating rod after the oil well stops spraying.

[0052] The formation temperature at the depth of the well where the electric heating cable is lowered is determined according to the geothermal gradient. When the formation temperature at the depth of the well where the electric heating cable is lowered is greater than or equal to the wax precipitation temperature of the crude oil, high-temperature wax dissolution is performed through the electric heating cable.

[0053] Obtain the wax content of each oil well; for oil wells with a wax content of less than 12%, the wellhead temperature is increased to 10°C above the wax precipitation temperature of crude oil by relying on the electric heating cable every 20-30 days; for oil wells with a wax content of more than 18%, the wellhead temperature is increased to 12°C above the wax precipitation temperature of crude oil by relying on the electric heating cable every 10-15 days, and the wax melting time is 2 hours to achieve the purpose of dissolving wax.

[0054] For each oil well, when the temperature of the produced liquid at the wellhead is 5°C lower than the freezing point of crude oil, the ground electric heating control cabinet is used to control the electric heating cable to start running; when the temperature of the produced liquid at the wellhead is more than 5°C higher than the freezing point of crude oil, the ground electric heating control cabinet is used to control the electric heating cable to stop running.

[0055] For each oil well, based on the crude oil viscosity-temperature curve, when the crude oil viscosity corresponding to the wellhead output liquid temperature is less than or equal to 50 mPas, the electric heating control cabinet is used to control the electric heating cable to stop running.

[0056] Example 5

[0057] A method for controlling energy consumption of an oil well electric heating cable, comprising:

[0058] Collect relevant parameters of each oil well, including crude oil solidification point, crude oil wax precipitation temperature, geothermal gradient, wellhead output fluid temperature and crude oil viscosity-temperature curve;

[0059] The operation of the electric heating cable is controlled according to the relevant parameters of each oil well. The method used for the heating cable is the constant power control method, and the power value of the electric heating cable is determined by the constant power control method, that is, the power value of the heating cable of the well is determined according to the liquid production and water content. The electric heating cable is a heating cable, and the heating cable is cylindrical with a diameter of 15mm, so that it can be put into the electric heating rod after the oil well stops spraying.

[0060] The formation temperature at the depth of the well where the electric heating cable is lowered is determined according to the geothermal gradient. When the formation temperature at the depth of the well where the electric heating cable is lowered is greater than or equal to the wax precipitation temperature of the crude oil, high-temperature wax dissolution is performed through the electric heating cable.

[0061] Obtain the wax content of each oil well; for oil wells with a wax content of less than 12%, every 27 days, the wellhead temperature is increased to 10°C above the wax precipitation temperature of crude oil by relying on the electric heating cable; for oil wells with a wax content of more than 18%, every 11 days, the wellhead temperature is increased to 12°C above the wax precipitation temperature of crude oil by relying on the electric heating cable, and the wax melting time is 2 hours to achieve the purpose of dissolving wax.

[0062] For each oil well, when the temperature of the produced liquid at the wellhead is 5°C lower than the freezing point of crude oil, the ground electric heating control cabinet is used to control the electric heating cable to start running; when the temperature of the produced liquid at the wellhead is more than 5°C higher than the freezing point of crude oil, the ground electric heating control cabinet is used to control the electric heating cable to stop running.

[0063] For each oil well, based on the crude oil viscosity-temperature curve, when the crude oil viscosity corresponding to the wellhead output liquid temperature is less than or equal to 50 mPas, the electric heating control cabinet is used to control the electric heating cable to stop running.

[0064] Example 6

[0065] A method for controlling energy consumption of an oil well electric heating cable, comprising:

[0066] The relevant parameters of the oil well are collected, including the crude oil solidification point, crude oil wax precipitation temperature, geothermal gradient, wellhead output liquid temperature and crude oil viscosity-temperature curve; the well is a well in Xinghua 1 block, the crude oil solidification point of the well is 50°C, the crude oil wax precipitation temperature is 51°C, and the geothermal gradient is 2.2°C / 100m, that is, the formation temperature at 1500 meters is 50°C, corresponding to the crude oil viscosity of 50 mPas at 55°C. The crude oil viscosity-temperature curve is as follows: Figure 1 As shown;

[0067] During normal production, the temperature of the output liquid at the wellhead is controlled within 5°C of the crude oil freezing point, and the gathering and transportation pipelines are heated by a heating furnace or water-mixing heating to ensure normal crude oil gathering and transportation;

[0068] To ensure the normal production of the oil well, 1500 meters of electric heating cable was installed in the well. During normal production, the constant power method was adopted to keep the wellhead temperature and the output fluid temperature at 45-55℃. The wellhead temperature was raised to 63℃ every 10 days to achieve the purpose of completely removing wax. Figure 1As shown in the figure, when the wellhead temperature of the produced fluid is 55°C, the crude oil viscosity drops to 50 mPas, the oil well can be lifted normally, and the heating cable stops running. When the wellhead produced fluid crude oil is 45°C, the crude oil viscosity is close to 1500 mPas, but as the depth increases, the crude oil temperature continues to increase and the viscosity continues to decrease. At this time, it is necessary to start the heating cable to heat the crude oil to reduce the viscosity, thereby reducing the suspension point load of the pumping unit.

[0069] The purpose of the present invention is to provide a method for controlling energy consumption of electric heating cables in oil wells in response to the practical problems in the production process of oil wells that rely on cable heating. Determine the length of the electric heating cable lowered into the well, determine the temperature of the wellhead produced liquid, determine the operating time and parameters of the electric heating cable, give full play to the thermal efficiency of the electric heating cable, ensure the normal lifting of crude oil in the oil pipe, reduce the load on the suspension point of the pumping unit, ensure the normal production of the oil well, and reduce the energy consumption of the electric heating cable.

[0070] The foregoing is merely a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for controlling energy consumption of an oil well electric heating cable, characterized in that: include: Collect relevant parameters of each oil well, including crude oil solidification point, crude oil wax precipitation temperature, geothermal gradient, wellhead output fluid temperature and crude oil viscosity-temperature curve; The operation of the electric heating cable is controlled according to the relevant parameters of each oil well.

2. The oil well electric heating cable energy consumption control method according to claim 1 is characterized in that: The method used for the electric heating cable is a constant power control method, and the power value of the electric heating cable is determined by the constant power control method.

3. The oil well electric heating cable energy consumption control method according to claim 1, characterized in that: The electric heating cable comprises an electric heating hollow rod or a heating cable.

4. The oil well electric heating cable energy consumption control method according to claim 3 is characterized in that: The heating cable is cylindrical in shape with a diameter of 16 + 1mm.

5. The oil well electric heating cable energy consumption control method according to claim 1, characterized in that: The formation temperature at the depth of the well where the electric heating cable is lowered is determined according to the geothermal gradient. When the formation temperature at the depth of the well where the electric heating cable is lowered is greater than or equal to the wax precipitation temperature of the crude oil, high-temperature wax dissolution is performed through the electric heating cable.

6. The oil well electric heating cable energy consumption control method according to claim 1, characterized in that: Controlling the operation of the electric heating cable according to the relevant parameters of each oil well, including: Obtain the wax content of each oil well; For oil wells with wax content less than 12%, the wellhead temperature is raised to 10°C above the wax precipitation temperature of crude oil by relying on the electric heating cable every 20-30 days. For oil wells with wax content greater than 18%, the wellhead temperature is raised to 12°C above the wax precipitation temperature of crude oil by relying on the electric heating cable every 10-15 days. The wax melting time is 2 hours to achieve the purpose of dissolving wax.

7. The oil well electric heating cable energy consumption control method according to claim 1, characterized in that: Controlling the operation of the electric heating cable according to the relevant parameters of each oil well, including: For each oil well, when the temperature of the produced liquid at the wellhead is 5°C lower than the freezing point of crude oil, the ground electric heating control cabinet is used to control the electric heating cable to start running; when the temperature of the produced liquid at the wellhead is more than 5°C higher than the freezing point of crude oil, the ground electric heating control cabinet is used to control the electric heating cable to stop running.

8. The oil well electric heating cable energy consumption control method according to claim 1, characterized in that: Controlling the operation of the electric heating cable according to the relevant parameters of each oil well, including: For each oil well, based on the crude oil viscosity-temperature curve, when the crude oil viscosity corresponding to the wellhead output liquid temperature is less than or equal to 50 mPas, the electric heating control cabinet is used to control the electric heating cable to stop running.

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