Oil field well head heating and deicing system and using method

Abstract

The invention belongs to the technical field of stepped efficient functions, and discloses an oil field well head heating and deicing system and a using method.The oil field well head heating and deicing system comprises a solar heat collector and a well head heating cover, the well head heating cover is provided with a heat preservation shell, and well head equipment and fused salt heat storage equipment are arranged in the heat preservation shell; the fused salt heat storage equipment is provided with an inlet pipeline and an outlet pipeline; the solar heat collector is respectively connected with the inlet pipeline and the outlet pipeline through pipelines; the fused salt heat storage equipment is provided with a heat preservation layer. Heat storage fused salt is arranged in the heat preservation layer, and gaps are reserved between the heat storage fused salt and the top and the bottom of the heat preservation layer; a heat exchange pipeline is inserted into the heat storage fused salt, and the two ends of the heat exchange pipeline extend out of the top and the bottom of the heat storage fused salt correspondingly; the inlet pipeline extends into the top of the insulating layer, and the outlet pipeline extends into the bottom of the insulating layer. Fused salt energy storage equipment is used for being coupled with the solar heat collector, heat storage and heat dissipation are integrated, and long-term uninterrupted efficient heat exchange of the system without manual operation is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of cascade high-efficiency functions, and in particular relates to an oilfield wellhead heating and deicing system and a use method thereof. Background Art

[0002] In cold climates, the oil in the wellhead and pipeline of an oil field may solidify or freeze, causing production interruption. Wellhead heating and deicing technology can effectively solve this problem. By heating the wellhead and pipeline, the viscosity of the oil can be reduced, the flow resistance can be reduced, the normal flow of oil can be ensured, and the production of the oil field can be guaranteed, thereby increasing the oil output and production efficiency. The existing oil field wellhead heating equipment uses electric heating heaters to solve the problem of winter antifreeze and thawing, but the electric heating is unstable on-site and requires regular maintenance by personnel, which increases personnel costs and is not economical.

[0003] The Chinese patent publication number is CN110068155A, and the name is a patent application for a molten salt linear Fresnel collector field anti-condensation system and method thereof, which includes a high-position molten salt expansion tank, a linear Fresnel collector field, a low-temperature molten salt tank, a high-temperature molten salt tank, and a molten salt heating unit; the molten salt outlet of the molten salt expansion tank is connected to the molten salt inlet of the molten salt heating unit through the expansion tank outlet pipe, and the molten salt outlet of the molten salt heating unit is connected to the molten salt inlet of the linear Fresnel collector field through the heater outlet pipe. Although this patent application uses molten salt for energy storage, it cannot achieve long-term continuous and efficient heat exchange. Summary of the invention

[0004] In order to overcome the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide an oilfield wellhead heating and deicing system and a method of use, which uses a molten salt energy storage device to couple a solar collector to integrate heat storage and heat dissipation, thereby realizing uninterrupted and efficient heat exchange without human operation for a long time.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] An oilfield wellhead heating and deicing system comprises: a solar collector and a wellhead heating cover, wherein the wellhead heating cover has a heat-insulating shell, wherein the heat-insulating shell has a wellhead device and a molten salt heat storage device; the molten salt heat storage device has an inlet pipe and an outlet pipe; the solar collector is connected to the inlet pipe and the outlet pipe respectively through pipes; the molten salt heat storage device has a heat-insulating layer; the heat-insulating layer has heat-storage molten salt, and gaps are left between the heat-storage molten salt and the top and bottom of the heat-storage layer; a heat-exchange pipe is inserted into the heat-storage molten salt, and the two ends of the heat-exchange pipe extend from the top and bottom of the heat-storage molten salt respectively; the inlet pipe extends into the top of the heat-insulating layer, and the outlet pipe extends into the bottom of the heat-insulating layer.

[0007] Optionally, a delivery pump is provided on the pipeline connecting the solar collector and the molten salt heat storage device.

[0008] Optionally, a partition is provided at the bottom of the heat storage molten salt.

[0009] Optionally, an electric heater is provided in the gap between the bottom of the heat storage molten salt and the bottom of the insulation layer.

[0010] Optionally, a temperature sensor is provided on a side of the top of the heat-insulating shell away from the molten salt heat storage device, and the temperature sensor is electrically connected to the electric heater.

[0011] Optionally, a detection port is provided on a side of the thermal insulation shell away from the molten salt heat storage device.

[0012] Optionally, a base is provided at the inner bottom of the thermal insulation shell, and the molten salt heat storage equipment and the wellhead equipment are both arranged on the top of the base; the base is made of insulating material.

[0013] Optionally, the solar collector has a cleaning device, which includes a surface dirt detection device, a cleaning motor and a cleaning brush. The solar collector has multiple solar heating tubes, a sliding rod is provided at the middle part of the outer side of the solar collector, and the cleaning brush is slidably installed on the sliding rod. The cleaning brush is connected to the cleaning motor through a transmission mechanism; the surface dirt detection device is arranged at the end of the solar collector and is electrically connected to the cleaning motor.

[0014] Optionally, the thickness of the insulation layer on the equipment surface facing the wellhead in the molten salt heat storage device is smaller than the thickness of the insulation layer on other surfaces.

[0015] The method for using the oilfield wellhead heating and deicing system comprises the following steps:

[0016] Filling the intermediate heat exchange medium into the solar collector for heating;

[0017] The intermediate heat exchange medium heated in the solar collector is sent into the insulation layer through the inlet pipe through the pipeline, and the heat is stored in the heat storage molten salt through the heat exchange pipe, and the wellhead equipment is heated by the heat storage molten salt;

[0018] The intermediate heat exchange medium flows back to the solar collector through the outlet pipe.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] An oilfield wellhead heating and deicing system of the present invention is connected with a solar collector based on molten salt energy storage to realize a closed cycle of the system and reduce the waste of intermediate heat exchange medium. The molten salt heat storage equipment and the wellhead equipment are arranged in the wellhead heating cover, and heat is conducted inside the wellhead heating cover to reduce heat loss. An insulation layer is arranged outside the wellhead heating cover of the present invention to prevent heat conduction into the atmosphere. The present invention adopts a heat exchange pipe to enhance the heat exchange coefficient between the intermediate heat exchange medium and the heat storage molten salt, and can realize the integration of heat storage and heat dissipation.

[0021] Furthermore, the present invention uses an electric heater to prevent the freezing of the wellhead equipment caused by continuous extreme weather. The angle of the solar collector is automatically adjusted to ensure the maximum efficient absorption of sunlight.

[0022] Furthermore, the surface of the solar collector of the present invention is arranged with a cleaning device, which detects adverse factors on the surface of the solar collector that affect the efficiency of the solar collector through the dirt detection device, and cleans the surface of the solar collector by driving the cleaning brush through the cleaning motor to ensure that the efficiency of the solar collector is not affected.

[0023] Further, a temperature sensor is arranged on the top of the wellhead equipment side of the wellhead heating cover of the present invention and is controlled and connected with the electric heater. The temperature is lowest here in the whole wellhead heating cover as a measuring point to ensure that the temperature of the whole wellhead equipment is within the required range.

[0024] Furthermore, a detection port is arranged on the wellhead equipment side of the wellhead heating cover of the present invention, so that the wellhead equipment can be detected and switched on and off without removing the wellhead heating cover.

[0025] Furthermore, the wellhead heating cover of the present invention is installed on a base with a heat-insulating function, which can prevent heat from being introduced into the formation.

[0026] Furthermore, the thickness of the insulation material around the molten salt heat storage device of the present invention is set to be different, so that more heat is introduced into the wellhead equipment side, ensuring that the wellhead equipment is not frozen. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings described herein are for explanation purposes only and are not intended to limit the scope of the present invention in any way. In addition, the shapes and proportional dimensions of the components in the drawings are only for illustration purposes to help understand the present invention, and are not intended to specifically limit the shapes and proportional dimensions of the components of the present invention. In the drawings:

[0028] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0029] Figure 2 This is a schematic diagram of the molten salt heat storage device of the present invention;

[0030] Among them, 1. solar collector; 2. cleaning device; 201. surface dirt detection device; 202. cleaning motor; 203. cleaning brush; 3. molten salt heat storage equipment; 301. inlet pipe; 302. heat exchange pipe; 303. heat storage molten salt; 304. electric heater; 305. outlet pipe; 306. insulation layer; 4. wellhead equipment; 5. wellhead heating cover; 501. detection port; 502. insulation shell; 6. delivery pump; 7. base; 8. temperature sensor. DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0032] It should be noted that when an element is referred to as being "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only embodiment.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0034] The present invention is described in detail below with reference to the accompanying drawings.

[0035] like Figure 1 As shown, an oilfield wellhead heating and deicing system of the present invention comprises: a solar collector 1 and a wellhead heating cover 5 , wherein the wellhead heating cover 5 has a heat-insulating shell 502 .

[0036] The insulation shell 502 contains a wellhead device 4 and a molten salt heat storage device 3; the molten salt heat storage device 3 has an inlet pipe 301 and an outlet pipe 305; the solar collector 1 is connected to the inlet pipe 301 and the outlet pipe 305 respectively through pipes; the molten salt heat storage device 3 has an insulation layer 306.

[0037] The thermal insulation layer 306 contains a heat storage molten salt 303, and gaps are left between the heat storage molten salt 303 and the top and bottom of the thermal insulation layer 306; a heat exchange pipe 302 is inserted into the heat storage molten salt 303, and both ends of the heat exchange pipe 302 extend from the top and bottom of the heat storage molten salt 303 respectively; the inlet pipe 301 extends into the top of the thermal insulation layer 306, and the outlet pipe 305 extends into the bottom of the thermal insulation layer 306.

[0038] A partition is provided at the bottom of the heat storage molten salt 303. An electric heater 304 is provided in the gap between the bottom of the heat storage molten salt 303 and the bottom of the insulation layer 306.

[0039] The solar thermal collector 1 has a cleaning device 2 .

[0040] A detection port 501 is provided on the side of the heat-insulating shell 502 away from the molten salt heat storage device 3 .

[0041] A base 7 is provided at the inner bottom of the heat-insulating shell 502 , and the molten salt heat storage device 3 and the wellhead device 4 are both provided on the top of the base 7 .

[0042] Example 1

[0043] An oilfield wellhead heating and deicing system comprises: a solar collector 1 and a wellhead heating cover 5, wherein the wellhead heating cover 5 has a heat-insulating shell 502, and the heat-insulating shell 502 has a wellhead device 4 and a molten salt heat storage device 3. The solar collector 1 has a cleaning device 2, and the cleaning device 2 comprises a surface dirt detection device 201, a cleaning motor 202 and a cleaning brush 203.

[0044] The solar thermal collector 1 has a plurality of solar heating tubes therein.

[0045] Optionally, a slide bar is provided at the middle of the outer side of the solar collector 1, the cleaning brush 203 is slidably mounted on the slide bar, the surface dirt detection device 201 is provided at the end of the solar collector 1, and is electrically connected to the cleaning motor 202. The cleaning brush 203 is connected to the cleaning motor 202 via a chain.

[0046] Optionally, the cleaning motor 202 is a linear motor with a slider, and the cleaning brush 203 is mounted on the slider.

[0047] The thermal insulation layer 306 is made of heat-insulating material. Optionally, the thermal insulation layer 306 is made of aluminum silicate fiber wool.

[0048] The heat-insulating shell 502 is made of a material with low thermal conductivity. Optionally, the heat-insulating shell 502 is made of glass fiber reinforced plastic.

[0049] The solar collector 1 has a plurality of solar heating tubes inside, and the solar heating tubes are connected to the molten salt heat storage device 3 through pipelines. The solar heating tubes have an intermediate heat exchange medium inside, and the intermediate heat exchange medium uses a low-temperature resistant intermediate heat exchange medium. Specifically, the intermediate heat exchange medium uses a low-temperature resistant medium. Optionally, the intermediate heat exchange medium uses ethylene glycol or brine or dichloromethane, which can prevent the intermediate heat exchange medium from freezing in extreme weather with sudden cold.

[0050] A slide bar is provided at the middle of the outer side of the solar collector 1, and the solar heating tube is provided on both sides of the slide bar. The cleaning brush 203 is slidably mounted on the slide bar, and the cleaning brush 203 is connected to the cleaning motor 202 via a chain; the surface dirt detection device 201 is provided at the end of the solar collector 1, and is electrically connected to the cleaning motor 202. The dirt detection device can detect dust, snow, and rain on the surface of the solar collector 1, so as to avoid affecting the heat collection efficiency of the solar collector 1.

[0051] When the surface dirt detection device 201 detects that dust, snow and rainwater have accumulated on the surface of the solar collector 1 to a certain extent, the cleaning motor 202 starts to drive the cleaning brush 203 to move up and down to clean the dust, snow and rainwater accumulated on the surface.

[0052] The solar collector 1 is equipped with sensors and control systems. The sensors can detect the position and light intensity of the sun in real time and transmit this information to the control system of the solar collector 1. The control system calculates the angle and direction that the solar collector 1 needs to be adjusted based on this information, and realizes the automatic rotation of the photovoltaic panel through the internal driving mechanism to ensure that the solar collector 1 always faces the sun.

[0053] The molten salt heat storage device 3 has an inlet pipe 301 and an outlet pipe 305; the solar collector 1 is connected to the inlet pipe 301 and the outlet pipe 305 through pipes respectively.

[0054] Preferably, the outlet pipe 305 is a curved pipe on the inner side of the insulation layer 306, and the end thereof is directed toward the bottom of the insulation layer 306, so as to make full use of the intermediate heat exchange medium and avoid the intermediate heat exchange medium being unable to be extracted.

[0055] Specifically, a delivery pump 6 is provided on the pipeline connecting the solar collector 1 and the molten salt heat storage device 3 .

[0056] Specifically, the top of the solar thermal collector 1 is provided with an outflow pipe on both sides respectively, the bottom of the solar thermal collector 1 is provided with an inflow pipe, and the delivery pump 6 is arranged on the pipe connecting the inflow pipe and the molten salt heat storage device 3.

[0057] The molten salt heat storage device 3 has a heat-insulating layer 306; the heat-insulating layer 306 contains a heat-storage molten salt 303, and gaps are left between the top and bottom of the heat-storage molten salt 303 and the heat-insulating layer 306. A heat-exchange pipe 302 is inserted into the heat-storage molten salt 303, and both ends of the heat-exchange pipe 302 extend from the top and bottom of the heat-storage molten salt 303 respectively; the inlet pipe 301 extends into the top of the heat-insulating layer 306, and the outlet pipe 305 extends into the bottom of the heat-insulating layer 306. By adopting a heat-exchange pipe 302 with a strong heat-exchange efficiency, the heat-exchange coefficient between the intermediate heat-exchange medium and the heat-storage molten salt 303 can be enhanced.

[0058] Furthermore, the heat exchange pipe 302 has finned tubes with increased heat exchange area, which can enhance its heat exchange efficiency.

[0059] Preferably, the thickness of the insulation layer 306 on the side facing the wellhead device 4 is smaller than that on the side facing away from the wellhead device 4, so that more heat is introduced into the wellhead device 4 to ensure that the wellhead device is not frozen. Testing at the lowest temperature point in the entire wellhead heating cover 5 can ensure that the temperature of the entire wellhead device 4 is within the required range.

[0060] Specifically, the thickness of the insulation layer 306 on the surface facing the wellhead device 4 in the molten salt heat storage device 3 is smaller than the thickness of the insulation layer 306 on other surfaces.

[0061] Specifically, the heat exchange pipes 302 are two in number and are arranged in parallel.

[0062] Specifically, a partition is provided at the bottom of the heat storage molten salt 303. Optionally, a partition is provided at the top of the heat storage molten salt 303. The partition is fixedly connected to the inner wall of the insulation layer 306, and both ends of the heat exchange pipe 302 pass through the partition.

[0063] An electric heater 304 is provided in the gap between the bottom of the heat storage molten salt 303 and the bottom of the insulation layer 306. A temperature sensor 8 is provided on the top of the insulation shell 502 away from the molten salt heat storage device 3, and the temperature sensor 8 is electrically connected to the electric heater 304. The electric heater 304 can prevent the freezing of the wellhead equipment 4 caused by continuous extreme weather.

[0064] The side of the heat-insulating shell 502 away from the molten salt heat storage device 3 is provided with a detection port 501, so that the wellhead device 4 can be detected and switched without removing the wellhead heating cover 5.

[0065] Specifically, the detection port 501 is a manhole door.

[0066] The inner bottom of the heat-insulating shell 502 is provided with a base 7, and the molten salt heat storage device 3 and the wellhead device 4 are both arranged on the top of the base 7. The base 7 can prevent heat from being introduced into the formation.

[0067] Example 2

[0068] The oilfield wellhead heating and deicing system of the present invention, when used, comprises the following steps:

[0069] The intermediate heat exchange medium is charged into the solar thermal collector 1 for heating.

[0070] The heated intermediate heat exchange medium in the solar collector 1 is passed into the inlet pipe 301 from both ends through the outflow pipe, and sent into the insulation layer 306, and the heat is stored in the heat storage molten salt 303 through the heat exchange pipe 302, and the wellhead equipment 4 is heated by the heat storage molten salt 303 storing heat.

[0071] The intermediate heat exchange medium is pumped into the inflow pipe of the solar collector 1 through the outlet pipe 305 by the delivery pump 6, so as to realize the closed circulation of the system and reduce the waste of the intermediate heat exchange medium.

[0072] When the temperature sensor 8 detects that the temperature is too low, the electric heater 304 is started to prevent the intermediate heat exchange medium from freezing. When the surface dirt detection device 201 detects that there is dirt on the surface of the solar collector 1, the cleaning motor 202 is started to remove the dirt through the cleaning brush 203.

[0073] Unless otherwise specified, the device elements involved in the above embodiments are all conventional device elements, and the structural settings, working modes or control modes involved are all conventional settings, working modes or control modes in the art unless otherwise specified.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Other modifications or equivalent substitutions made to the technical solution of the present invention by ordinary technicians in the field should be included in the scope of the claims of the present invention as long as they do not depart from the spirit and scope of the technical solution of the present invention.

Claims

1. An oilfield wellhead heating and deicing system, characterized in that: include: A solar thermal collector (1) and a wellhead heating cover (5), wherein the wellhead heating cover (5) has a heat-insulating shell (502), wherein the wellhead equipment (4) and a molten salt heat storage device (3) are arranged in the heat-insulating shell (502); the molten salt heat storage device (3) has an inlet pipe (301) and an outlet pipe (305); the solar thermal collector (1) is connected to the inlet pipe (301) and the outlet pipe (305) respectively through pipes; the molten salt heat storage device (3) has a heat-insulating layer (306 ); the thermal insulation layer (306) contains a heat storage molten salt (303), and gaps are left between the top and bottom of the heat storage molten salt (303) and the thermal insulation layer (306); a heat exchange pipe (302) is inserted into the heat storage molten salt (303), and the two ends of the heat exchange pipe (302) extend from the top and bottom of the heat storage molten salt (303) respectively; the inlet pipe (301) extends into the top of the thermal insulation layer (306), and the outlet pipe (305) extends into the bottom of the thermal insulation layer (306).

2. The oilfield wellhead heating and deicing system according to claim 1, characterized in that: A delivery pump (6) is provided on the pipeline connecting the solar thermal collector (1) and the molten salt heat storage device (3).

3. The oilfield wellhead heating and deicing system according to claim 1, characterized in that: A partition is provided at the bottom of the heat storage molten salt (303).

4. The oilfield wellhead heating and deicing system according to claim 1, characterized in that: An electric heater (304) is provided in the gap between the bottom of the heat storage molten salt (303) and the bottom of the thermal insulation layer (306).

5. The oilfield wellhead heating and deicing system according to claim 4, characterized in that: A temperature sensor (8) is provided on a side of the top of the heat-insulating shell (502) away from the molten salt heat storage device (3), and the temperature sensor (8) is electrically connected to the electric heater (304).

6. The oilfield wellhead heating and deicing system according to claim 1, characterized in that: A detection port (501) is provided on the side of the heat-insulating shell (502) away from the molten salt heat storage device (3).

7. The oilfield wellhead heating and deicing system according to claim 1, characterized in that: A base (7) is provided at the inner bottom of the heat-insulating shell (502), and the molten salt heat storage device (3) and the wellhead device (4) are both arranged on the top of the base (7); the base (7) is made of a heat-insulating material.

8. The oilfield wellhead heating and deicing system according to claim 1, characterized in that: The solar thermal collector (1) has a cleaning device (2), the cleaning device (2) comprising a surface dirt detection device (201), a cleaning motor (202) and a cleaning brush (203); a plurality of solar heating tubes are provided in the solar thermal collector (1); a sliding rod is provided in the middle of the outer side of the solar thermal collector (1); the cleaning brush (203) is slidably mounted on the sliding rod; the cleaning brush (203) and the cleaning motor (202) are connected via a transmission mechanism; the surface dirt detection device (201) is provided at the end of the solar thermal collector (1) and is electrically connected to the cleaning motor (202).

9. The oilfield wellhead heating and deicing system according to claim 1, characterized in that: The thickness of the thermal insulation layer (306) on the surface of the molten salt heat storage device (3) facing the wellhead device (4) is smaller than the thickness of the thermal insulation layer (306) on other surfaces.

10. A method for using an oilfield wellhead heating and deicing system according to any one of claims 1 to 9, characterized in that: The following steps are involved: Filling the intermediate heat exchange medium into the solar collector (1) for heating; The intermediate heat exchange medium heated in the solar collector (1) is sent into the insulation layer (306) through the inlet pipe (301) through the pipe, and the heat is stored in the heat storage molten salt (303) through the heat exchange pipe (302), and the wellhead equipment (4) is heated by the heat storage molten salt (303); The intermediate heat exchange medium flows back to the solar collector (1) through the outlet pipe (305).

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