Oilfield downhole camera system and oilfield downhole camera method

Abstract

This invention provides an oilfield downhole camera system and method. The system includes: a hollow protective tube installed inside the tubing string and connected to the tubing string via a connector; an imaging device installed at the bottom inside the hollow protective tube for capturing images of the oil well interior; a signal transmitting device installed at the top inside the hollow protective tube and connected to the imaging device for transmitting the acquired images of the oil well interior; a signal receiving device connected to a tubing valve installed at the top of the tubing string for receiving the images of the oil well interior; a fluid injection device with its outlet connected to the tubing valve for injecting water into the hollow protective tube; and a return fluid treatment device with its inlet connected to an annular valve installed at the top of the oil well casing for treating the return water from the oil well. The oilfield downhole camera system of this invention has the advantages of simple structure, ease of use, high imaging quality, and the ability to display images in real time.

Description

Technical Field

[0001] This invention relates to the field of oilfield downhole camera technology, specifically to an oilfield downhole camera system and an oilfield downhole camera method. Background Technology

[0002] As oilfield development progresses, the number of wells with casing damage or defects continues to increase. Therefore, visible light imaging wellbore inspection technology is often used to intuitively understand the downhole conditions, formulate targeted and reasonable casing damage prevention and control measures, thereby improving the timeliness of well workover operations and reducing well workover costs.

[0003] Currently, downhole visible light imaging technology can be divided into two types based on whether images can be acquired in real time: storage-type and direct-reading-type. Storage-type instruments are battery-powered and lowered into the well with a wireline. Their advantage is that the wireline easily achieves wellhead sealing, making them suitable for testing high-pressure wells. Furthermore, images acquired by storage-type instruments are stored in an internal memory, allowing data playback after the instrument is brought to the surface. Storage-type instruments are relatively simple to develop and have lower costs. However, the images acquired by storage-type instruments cannot be viewed in real time, preventing timely understanding of downhole conditions and targeted adjustments during testing. Direct-reading downhole imaging technology is more widely used than storage-type, but its high technical difficulty, development, and operating costs result in high prices for single-well technical services. Additionally, the harsh downhole environment in oilfields (high temperature, high pressure, oil contamination) and complex imaging conditions, coupled with the significant impact of suspended oil and particulate matter in the well fluid on obtaining clear images, lead to less than ideal testing results. Existing visible light imaging technology, due to its high cost and unsatisfactory testing results, cannot meet the increasing demand for wellbore integrity inspections in oilfields. Summary of the Invention

[0004] The purpose of this invention is to provide an oilfield downhole camera system and method to solve the problems mentioned above, which are that the system is expensive, the testing results are not ideal, and it cannot meet the increasing demand for wellbore integrity inspection in oilfields.

[0005] To achieve the above objectives, embodiments of the present invention provide an oilfield downhole camera system. An oil well in the oilfield has a casing, and a tubing string capable of vertical movement within the casing is mounted on the casing. The system includes:

[0006] A hollow protective tube is vertically installed inside the tubing string. The hollow protective tube is connected to the tubing string via a connector and can move vertically with the tubing string inside the well casing.

[0007] The imaging device is installed at the bottom of the hollow protective tube and is used to capture images of the inside of the oil well.

[0008] A signal transmitting device is installed at the top of the hollow protective tube and connected to the imaging device for transmitting acquired images of the inside of the oil well.

[0009] A signal receiving device is connected to a tubing valve located at the top of the tubing string to receive images of the inside of the well.

[0010] The liquid injection device has its outlet connected to the oil pipe valve and is used to inject liquid into the hollow protective pipe.

[0011] A return fluid treatment device, wherein the inlet of the return fluid treatment device is connected to an annular valve located at the top of the oil well casing, for treating the return fluid from the oil well.

[0012] Optionally, the system further includes:

[0013] A hollow and sealed protective shell is installed inside the hollow protective tube by a shock-absorbing device. The imaging device is located inside the protective shell. A transparent window is provided at the bottom end of the protective shell. The imaging device captures images of the inside of the oil well through the transparent window.

[0014] Optionally, the shock absorption device includes:

[0015] Multiple shock-absorbing springs are spaced apart on the outer wall of the protective shell. One end of each shock-absorbing spring is fixed to the outer wall of the protective shell, and the other end is fixed to the inner wall of the hollow protective tube.

[0016] Optionally, the shock-absorbing spring is a conical spring, with the small end of each conical spring fixed to the outer wall of the protective shell and the large end fixed to the inner wall of the hollow protective tube.

[0017] Optionally, the system further includes:

[0018] An illumination device is located at the bottom of the protective housing and is used to provide supplemental lighting when the shooting device is taking pictures.

[0019] Optionally, the lighting device includes:

[0020] An annular bracket is connected to the bottom of the protective housing via a support rod;

[0021] A lighting fixture is mounted on the annular bracket.

[0022] Optionally, the system further includes:

[0023] A power supply device is disposed inside the protective housing and connected to the shooting device and the signal transmitting device, for supplying power to the shooting device and the signal transmitting device.

[0024] Optionally, the system further includes:

[0025] A power generation device is installed inside the top of the hollow protective tube and connected to the power supply device. The power generation device generates electricity based on the injected liquid and charges the power supply device.

[0026] Optionally, a retaining ring is provided inside the bottom end of the hollow protective tube to prevent the protective shell from detaching from the hollow protective tube.

[0027] Optionally, the system further includes:

[0028] A ranging device is installed inside the bottom of the protective housing and is used to obtain the distance between the protective housing and the object inside the oil well through the transparent window.

[0029] Optionally, the system further includes:

[0030] A pressure detection device is installed on the protective housing to obtain the pressure value inside the oil well.

[0031] Optionally, the system further includes:

[0032] A temperature detection device is installed on the protective casing to obtain the temperature value inside the oil well.

[0033] Optionally, the signal transmitting device is a pressure pulse generator, and the signal receiving device is a pressure pulse receiver, wherein the pressure pulse generator uses the liquid injected into the hollow protective tube as the signal transmission medium.

[0034] Optionally, the injection device includes:

[0035] A liquid storage tank is connected to the oil pipe valve via a first pipe, and a water pump, flow meter and pressure gauge are installed on the first pipe.

[0036] Optionally, the liquid return treatment device includes:

[0037] The liquid purification tank is connected to the annular valve of the oil well casing via a second pipe. The liquid purification tank is equipped with a turbidity meter. The liquid purification tank's drain outlet is connected to the storage tank via a third pipe. The liquid purification tank's sewage outlet is connected to a sewage tank via a fourth pipe.

[0038] Optionally, the connector is a hollow frustum-shaped connector, with the large end of the connector connected to the oil pipe string and the small end connected to the top of the hollow protective tube.

[0039] A second aspect of the present invention provides a method for oilfield downhole imaging, implemented using the aforementioned oilfield downhole imaging system, the method comprising:

[0040] As the hollow protective tube inside the tubing string descends with the tubing string, an imaging device captures real-time images of the inside of the well. Simultaneously, a pressure detection device obtains the pressure value at the location of the imaging device, and a temperature detection device obtains the temperature value at the location of the imaging device.

[0041] When the pressure value is within a first preset pressure range and the temperature value is within a preset temperature range, the shooting device is controlled to stop working; and when the pressure value is within a second preset pressure range, the shooting device is controlled to stop working.

[0042] The first preset pressure range is greater than the second preset pressure range.

[0043] Optionally, the method further includes:

[0044] If the temperature value is greater than the preset temperature threshold, the liquid injection device is controlled to inject water into the hollow protective tube.

[0045] The preset temperature threshold is greater than any temperature value in the preset temperature range.

[0046] Optionally, the method further includes:

[0047] Based on real-time acquired images of the interior of the oil well, the clarity of the images is determined.

[0048] The injection speed of the injection device into the hollow protective pipe is adjusted based on the clarity of the image inside the oil well.

[0049] Optionally, the method further includes:

[0050] The distance between the protective shell and the object inside the oil well is obtained in real time;

[0051] If the spacing is less than or equal to the preset spacing, the hollow protective tube is controlled to descend at a preset speed;

[0052] If the spacing is greater than the preset spacing, the hollow protective tube is controlled to stop descending.

[0053] This technical solution features a simple structure and ease of use. It acquires real-time images of the oil well's interior via an imaging device and transmits the image information via a signal transmitter. A signal receiver on the ground receives and displays the image information in real time, allowing for continuous monitoring of the well's underground status. Additionally, an injection device injects liquid into the hollow protective tube to cool and protect the imaging device, improving image quality. A return fluid treatment device processes the returned fluid, enabling its recycling and reducing environmental pollution.

[0054] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0055] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings:

[0056] Figure 1 This is a schematic diagram of the structure of the oilfield downhole camera system provided by the present invention;

[0057] Figure 2 This is a schematic diagram of the structure of the lighting device provided by the present invention;

[0058] Figure 3 This is a schematic diagram of the control circuit provided by the present invention.

[0059] Explanation of reference numerals in the attached figures

[0060] 1-Hollow protective tube; 2-Shooting device; 3-Signal transmitting device;

[0061] 4-Signal receiving device; 5-Liquid injection device; 6-Liquid return treatment device;

[0062] 7-Protective housing; 8-Shock absorption device; 11-Connector;

[0063] 12-Tubing string; 13-Well casing; 14-Retaining ring;

[0064] 21-Lighting fixture; 22-Power supply device; 23-Power generation device;

[0065] 24-Distance measuring device; 25-Pressure detection device; 26-Temperature detection device;

[0066] 51-Storage tank; 52-First pipeline; 53-Water pump;

[0067] 54-Flow meter; 55-Pressure gauge; 61-Liquid purification tank;

[0068] 62-Second pipe; 63-Turbidimeter; 64-Third pipe;

[0069] 65-Fourth pipe; 66-Sewage tank; 71-Transparent viewing window;

[0070] 121-Tubing valve; 131-Oil jacket annulus valve; 211-Annular bracket;

[0071] 212-Support rod; 213-Lighting lamp. Detailed Implementation

[0072] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of the present invention.

[0073] In the embodiments of the present invention, unless otherwise stated, directional terms such as "up," "down," "left," and "right" generally refer to the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use.

[0074] The terms “first,” “second,” “third,” etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0075] The terms "parallel" and "perpendicular" do not mean that the components must be absolutely parallel or perpendicular, but rather that they can be slightly tilted. For example, "parallel" simply means that its direction is more parallel than "perpendicular," not that the structure must be completely parallel, but that it can be slightly tilted.

[0076] The terms "horizontal," "vertical," and "sag" do not imply that a component must be absolutely horizontal, vertical, or sagging, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," not that the structure must be completely horizontal, but can be slightly tilted.

[0077] Furthermore, terms like "roughly" and "basically" are used to indicate that the content does not require absolute precision, but rather allows for a certain degree of deviation. For example, "roughly equal" does not simply mean absolute equality; in actual production and operation, achieving absolute "equality" is difficult, and a certain degree of deviation is generally present. Therefore, besides absolute equality, "roughly equal to" also includes the aforementioned situation where a certain degree of deviation exists. Using this as an example, in other cases, unless otherwise specified, terms like "roughly" and "basically" have similar meanings.

[0078] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0079] Figure 1 This is a schematic diagram of the structure of the oilfield downhole camera system provided by the present invention; Figure 2 This is a schematic diagram of the lighting device provided by the present invention.

[0080] like Figure 1-2 As shown, this embodiment provides an oilfield downhole camera system. An oil well in the oilfield has an oil well casing 13, and a tubing string 12 capable of vertically moving within the oil well casing 13 is installed on the casing 13. The system includes:

[0081] A hollow protective tube 1 is vertically installed inside the tubing string 12. The hollow protective tube 1 is connected to the tubing string 12 via a connector 11 and can move vertically inside the well casing 13 along with the tubing string 12.

[0082] The imaging device 2 is installed at the bottom of the hollow protective tube 1 and is used to capture images of the inside of the oil well.

[0083] The signal transmitting device 3 is located at the top of the hollow protective tube 1 and is connected to the imaging device 2 for transmitting acquired images of the inside of the oil well.

[0084] The signal receiving device 4 is connected to the tubing valve 121 located at the top of the tubing string 12, and is used to receive images inside the oil well;

[0085] The liquid injection device 5 has its outlet connected to the oil pipe valve 121 and is used to inject water into the hollow protective pipe 1.

[0086] The return fluid treatment device 6 has its inlet connected to the annular valve 131 located at the top of the oil well casing 13, and is used to treat the return water from the oil well.

[0087] Specifically, the well casing 13 is hollow inside, and a tubing string 12 is installed inside it. The top of the tubing string 12 is located outside the well casing 13, and the tubing string 12 can move up and down inside the well casing 13. In order to obtain the image inside the well casing 13, a hollow protective tube 1 is installed inside the tubing string 12. The hollow protective tube 1 and the tubing string 12 are detachably connected by a connector 11, which facilitates installation, disassembly, and maintenance. A camera 2 is fixed inside the hollow protective tube 1. As the tubing string 12 moves up and down inside the well casing 13, the camera 2 moves accordingly, thus moving up and down inside the well casing 13 to capture the internal image of the well casing 13. Furthermore, in order to ensure the shooting angle and shooting quality, the camera 2 is set at the bottom end of the hollow protective tube 1. At the same time, in order to achieve real-time signal transmission, a signal is transmitted through a connection to the camera 2. The signal transmitting device 3 transmits captured images in real time, and a corresponding signal receiving device 4 is set on the ground to receive the signals, thereby achieving real-time signal acquisition. To ensure the strength of signal reception and transmission, the signal transmitting device 3 is set at the top of the hollow protective tube 1, and the signal receiving device 4 is set at the tubing valve 121 at the top of the tubing string 12. At the same time, during the image capturing process, water is injected into the hollow protective tube 1 through the tubing string 12 via the injection device 5 to reduce the temperature of the capturing device 2. Simultaneously, it mixes with the precipitated fluid in the oil well to reduce the concentration of the precipitate, ensuring that the images can be captured after cleaning and improving the image quality. During the continuous injection of liquid into the oil well, the liquid will overflow from the annulus valve 131 at the top of the oil well casing 13. Therefore, a return fluid treatment device 6 is set up to treat the return fluid from the oil well to avoid environmental pollution caused by oil pollution in the return fluid.

[0088] More specifically, the liquid injected into the hollow protective tube 1 can be clean water. The imaging device 2 can be a CCD, camera, etc.

[0089] Furthermore, the system also includes:

[0090] A hollow and sealed protective shell 7 is installed inside the hollow protective tube 1 via a shock-absorbing device 8. The imaging device 2 is located inside the protective shell 7. A transparent window 71 is provided at the bottom end of the protective shell 7. The imaging device 2 captures images of the inside of the oil well through the transparent window 71.

[0091] Specifically, due to the harsh environment inside the oil well, the imaging device 2 is easily damaged due to prolonged exposure to such conditions. Therefore, to extend the service life of the imaging device 2, a protective outer shell 7 is installed inside the hollow protective tube 1. This shell is a sealed housing with a hollow interior, providing storage space. A shock-absorbing device 8 connects the protective outer shell 7 to the hollow protective tube 1, reducing axial and radial vibrations experienced by the protective shell 7 as the hollow protective tube 1 moves with the tubing string 12, thus preventing vibration from affecting the imaging quality. To ensure that the imaging device 2 can capture images, a transparent window 71 is provided at the lowest end of the protective shell 7. This allows the imaging device 2 to capture images of the inside of the oil well through the transparent window 71. Furthermore, the transparent window 71 is made of high-temperature and high-pressure resistant glass and is sealed to the protective shell 7.

[0092] In another embodiment, a heat insulation layer is provided on the innermost layer of the protective shell 7 to prevent heat from the oil well from being transferred into the hollow protective pipe 1, which would cause the imaging device 2 to overheat and be damaged.

[0093] Furthermore, the shock absorption device 8 includes:

[0094] Multiple shock-absorbing springs are spaced apart on the outer wall of the protective housing 7. One end of each shock-absorbing spring is fixed to the outer wall of the protective housing, and the other end is fixed to the inner wall of the hollow protective tube 1.

[0095] Specifically, using a spring as the shock absorber 8 reduces structural complexity and facilitates replacement. Multiple springs can be used, with multiple springs spaced apart on the outer walls of the top and bottom of the protective housing 7. One end of each spring is fixed to the outer wall of the protective housing 7, and the other end is fixed to the corresponding inner wall of the hollow protective tube 1.

[0096] Furthermore, the shock-absorbing spring is a conical spring, with the small end of each conical spring fixed to the outer wall of the protective shell 7 and the large end fixed to the inner wall of the hollow protective tube 1.

[0097] Specifically, conical springs are used, with the small end of each conical spring fixed to the outer wall of the protective shell 7 and the large end fixed to the inner wall of the hollow protective tube 1, which can better achieve shock absorption and improve the shock absorption effect.

[0098] Furthermore, the system also includes:

[0099] The lighting device 21 is located at the bottom of the protective housing 7 and is used to provide supplementary lighting when the shooting device 2 takes pictures.

[0100] Specifically, since the oil well is in a dark environment, it is impossible to guarantee the image capture command through the shooting device 2. Therefore, a lighting device 21 is installed at the bottom of the protective shell 7 to provide supplementary lighting. When shooting, the lighting device 21 works to emit light and illuminate the bottom area of ​​the hollow protective tube 1 to ensure the shooting quality.

[0101] Furthermore, the lighting device 21 includes:

[0102] The annular bracket 211 is connected to the bottom of the protective housing 7 via a support rod 212;

[0103] Lighting lamp 213 is mounted on the annular bracket 211.

[0104] Specifically, the shooting device 2 is independently configured as a detachable module, facilitating replacement in case of damage. In this embodiment, the lighting device 21 includes a ring bracket 211 and a lighting lamp 213. The ring bracket 211 is used to fix the lighting lamp 213, and the ring bracket 211 is connected to the bottom of the protective housing 7 via a support rod 212. More specifically, the end of the support rod 212 that contacts the protective housing 7 is provided with a threaded hole, allowing the support rod 212 to be fixed to the protective housing 7 with screws. The lighting lamp 213 can be embedded in the ring bracket 211, and the ring bracket 211 is waterproofed. The lighting lamp 213 can be an LED lamp.

[0105] In another embodiment, if the protective housing 7 is cylindrical, an annular connecting piece can be provided on the annular bracket 211. The inner wall of the annular connecting piece contacts the outer wall of the protective housing 7 and is rotatedly connected by threads.

[0106] In another embodiment, in order to protect the lighting device 21, the lighting device 21 is placed at the bottom inside the protective housing 7, so that the light emitted by the lighting lamp 213 passes through the transparent window 71 to achieve supplemental lighting.

[0107] Furthermore, the system also includes:

[0108] The power supply device 22 is disposed inside the protective housing 7 and is connected to the shooting device 2 and the signal transmitting device 3, and is used to supply power to the shooting device 2 and the signal transmitting device 3.

[0109] Specifically, to ensure that the shooting device 2 can maintain shooting for a longer period of time, a power supply device 22 is provided inside the protective housing 7 to supply power to the shooting device 2 and the signal transmitting device 3. More specifically, the power supply device 22 can be configured as a rechargeable lithium battery, a rechargeable lead-acid battery, etc., to achieve recycling.

[0110] Furthermore, the system also includes:

[0111] The power generation device 23 is located inside the top of the hollow protective tube 1 and is connected to the power supply device 22. The power generation device 23 generates electricity based on the injected liquid and charges the power supply device 22.

[0112] Specifically, the power supply device 22 can be configured as a rechargeable lithium battery or a rechargeable lead-acid battery. Therefore, a power generation device 23 is installed inside the top of the hollow protective tube 1. The power generation device 23 is located below the signal transmitting device 3, and the power supply device 22 is charged based on the injected liquid power generation.

[0113] More specifically, the power generation device 23 can be configured to include rotating blades, a generator set, and a voltage regulator. Under the impact of the injected liquid, the rotating blades rotate, driving the rotor in the generator set to rotate, cutting the magnetic field lines generated by the stator, thereby generating current. After being regulated by the voltage regulator, the current is used to charge the rechargeable lithium battery or rechargeable lead-acid battery. The voltage regulation technology of this voltage regulator has been maturely applied in various wind power generation scenarios, and will not be elaborated here.

[0114] Furthermore, a retaining ring 14 is provided inside the bottom end of the hollow protective tube 1 to prevent the protective outer shell 7 from detaching from the hollow protective tube 1.

[0115] Specifically, since the protective shell 7 has a certain weight and is only fixed by the shock-absorbing device 8, there is a possibility of it falling off. Therefore, in order to prevent the shock-absorbing device 8 from failing and causing the protective shell 7 to directly detach from the hollow protective pipe 1 and fall into the oil well, a retaining ring 14 is set at the bottom of the protective shell 7 to prevent the protective shell 7 from detaching from the hollow protective pipe 1.

[0116] Furthermore, the system also includes:

[0117] The ranging device 24 is disposed inside the bottom end of the protective housing 7 and is used to obtain the distance between the protective housing 7 and the object inside the oil well through the transparent window 71.

[0118] Specifically, since there may be foreign objects inside the oil well, a ranging device 24 is installed inside the bottom of the protective shell 7 to obtain the distance between the protective shell 7 and the object inside the oil well, so as to avoid collision and damage to the device.

[0119] More specifically, the ranging device 24 may be a laser ranging device, a radar ranging device, etc.

[0120] Furthermore, the system also includes:

[0121] A pressure detection device 25 is installed on the protective housing 7 and is used to obtain the pressure value inside the oil well.

[0122] Specifically, as the depth of the imaging device 2 increases, the external pressure it experiences also gradually increases. To prevent damage to the equipment under high pressure, a pressure detection device 25 is installed on the protective housing 7 to acquire pressure values ​​in real time. The pressure detection device 25 can be configured as a pressure sensor.

[0123] Furthermore, the system also includes:

[0124] Temperature detection device 26 is installed on the protective housing 7 and is used to obtain the temperature value inside the oil well.

[0125] Specifically, as the depth of the imaging device 2 increases, the temperature of its external environment will gradually increase. To prevent damage to the equipment due to high temperatures, a temperature detection device 26 is installed on the protective casing 7 to obtain the temperature value in real time. The temperature detection device 26 can be a thermocouple.

[0126] Furthermore, the signal transmitting device 3 is a pressure pulse generator, and the signal receiving device 4 is a pressure pulse receiver. The pressure pulse generator uses the liquid injected into the hollow protective tube 1 as the signal transmission medium.

[0127] Specifically, in this embodiment, the signal transmitting device 3 is a pressure pulse generator, the signal receiving device 4 is a pressure pulse receiver, and the transmission medium based on the injected liquid group can ensure the stability of data transmission.

[0128] In another implementation, a wireless communication module can be used for real-time, wireless signal transmission.

[0129] Furthermore, the injection device 5 includes:

[0130] The liquid storage tank 51 is connected to the oil pipe valve 121 through the first pipe 52. The first pipe 52 is equipped with a water pump 53, a flow meter 54 and a pressure gauge 55.

[0131] Specifically, the water pump 53 is configured as a frequency-adjustable motor, enabling adjustment of its operating power. The water pump 53 is connected to a water pump controller, which, according to instructions, controls the operating frequency of the water pump 53, thereby adjusting the liquid injection volume and injection speed. The flow meter 54 displays the flow rate of the injected liquid, and the pressure gauge 55 displays the pressure of the injected liquid in real time.

[0132] In another embodiment, the signal receiving device 4 may be disposed in the first pipe 52.

[0133] Furthermore, the liquid return treatment device 6 includes:

[0134] The liquid purification tank 61 is connected to the annular valve 131 of the oil well casing 13 via a second pipe 62. The liquid purification tank 61 is equipped with a turbidity meter 63. The drain port of the liquid purification tank 61 is connected to the storage tank 51 via a third pipe 64. The sewage outlet of the liquid purification tank 61 is connected to the sewage tank 66 via a fourth pipe 65.

[0135] Specifically, after a certain amount of liquid is injected into the oil well, the liquid in the oil well will be released outward through the annular valve 131. At this time, the returned liquid contains crude oil, and direct discharge will cause environmental pollution. Therefore, the liquid purification tank 61 collects and purifies the returned liquid through the second pipeline 62 and the annular valve 131 of the oil well casing 13. The turbidity of the returned liquid is detected by a turbidity meter 63 installed on the liquid purification tank 61. If the test meets the usage standards, it is discharged to the storage tank 51 through the third pipeline 64 for recycling. Some turbid liquid that cannot be treated is directly discharged to the sewage tank 66 through the fourth pipeline 65 for storage, so as to carry out subsequent harmless treatment.

[0136] Specifically, taking clean water as an example, the movement path of clean water is as follows: the clean water in the storage tank 51 passes through the water injection pump 53 through the tubing valve 121 → the inner cavity of the tubing string 12 (or the inner cavity of the continuous pipe) → the inner annulus (the gap between the hollow protective pipe 1 and the protective shell 7) → the annulus (the gap between the tubing string 12 and the well casing 13) → the annulus valve 131 → and returns to the sewage liquid purification tank 61 to purify the downhole sewage. After the turbidity meter 63 detects that it meets the requirements, it enters the storage tank 51 to form a circulating water utilization.

[0137] Furthermore, the connector 11 is a hollow frustum-shaped connector 11, with the large end of the connector 11 connected to the oil pipe string 12 and the small end connected to the top of the hollow protective pipe 1.

[0138] Specifically, the connector 11 is configured as a hollow frustum-shaped connector 11 to increase the flow rate of the liquid passing through the connector 11 and improve power generation efficiency. The small end of the connector 11 is fixed to the hollow protective tube 1. This can be achieved by providing an external thread at the small end of the connector 11 and an internal thread inside the top of the hollow protective tube 1, thus enabling a detachable connection. A limiting block is provided at the corresponding position on the tubing column 12 to limit the large end of the connector 11 and fix the hollow protective tube 1 inside the tubing column 12.

[0139] In another embodiment, a bolted connection can be used to fix the large end of the connector 11 to the tubing string 12.

[0140] A second aspect of the present invention also provides a method for oilfield downhole imaging, implemented using the aforementioned oilfield downhole imaging system, the method comprising:

[0141] As the hollow protective tube inside the tubing string descends with the tubing string, an imaging device captures real-time images of the inside of the well. Simultaneously, a pressure detection device obtains the pressure value at the location of the imaging device, and a temperature detection device obtains the temperature value at the location of the imaging device.

[0142] When the pressure value is within a first preset pressure range and the temperature value is within a preset temperature range, the shooting device is controlled to stop working; and when the pressure value is within a second preset pressure range, the shooting device is controlled to stop working.

[0143] The first preset pressure range is greater than the second preset pressure range.

[0144] Furthermore, the method also includes:

[0145] If the temperature value is greater than the preset temperature threshold, the liquid injection device is controlled to inject water into the hollow protective tube.

[0146] The preset temperature threshold is greater than any temperature value in the preset temperature range.

[0147] Furthermore, the method also includes:

[0148] Based on real-time acquired images of the interior of the oil well, the clarity of the images is determined.

[0149] The injection speed of the injection device into the hollow protective pipe is adjusted based on the clarity of the image inside the oil well.

[0150] Furthermore, the method also includes:

[0151] The distance between the protective shell and the object inside the oil well is obtained in real time;

[0152] If the spacing is less than or equal to the preset spacing, the hollow protective tube is controlled to descend at a preset speed;

[0153] If the spacing is greater than the preset spacing, the hollow protective tube is controlled to stop descending.

[0154] Figure 3 This is a schematic diagram of the control circuit provided by the present invention, as shown below. Figure 3 As shown, in another embodiment, a control circuit or controller is provided inside the protective housing 7 to achieve autonomous image capture. Specifically, it includes: a charging controller, an intelligent power supply system, a power supply module for the camera remote transmission system, a power supply module for the temperature and pressure acquisition system, a temperature and pressure acquisition module, a distance acquisition module, a CMOS camera module, a video acquisition circuit, an AI image recognition system, an encoder, and an LED light driving circuit.

[0155] The intelligent power supply system controls the switching of the power supply module of the remote camera transmission system by setting pressure and temperature values. The logic relationship is shown in Table 1 below:

[0156] Table 1. Control Logic Relationships under Different Pressures and Temperatures

[0157]

[0158] P- represents the downhole pressure, which can be set according to the downhole conditions and requirements of the well.

[0159] T- represents the downhole temperature. The temperature values ​​T1, T2, and T3 can be set according to the downhole working conditions and requirements of the well, and T1 < T2 < T3.

[0160] Based on the logic relationship between pressure and temperature, the power supply module of the camera remote transmission system is switched on and off to reduce the ineffective working time of the camera system, increase the number of battery cycles available, reduce circuit heat generation, avoid circuit overheating, and extend the service life of the camera.

[0161] When the temperature exceeds T3, its status is encoded and transmitted to the surface via a pressure pulse transmitter. The well-washing control system then activates a water pump to circulate and cool the downhole camera. For example... Figure 3 As shown.

[0162] The instrument has three working states: power on, power on, and power off.

[0163] There are five scenarios for downhole image recognition: clear, gray, black, abnormal pipe wall, and fallen object.

[0164] There are two types of rangefinders: those with a range greater than 1m and those with a range less than 1m.

[0165] The above three states, totaling ten conditions, are coded and prioritized according to a pre-set priority setting. The corresponding codes are then transmitted via a pulse generator, using circulating water as the transmission medium, to the surface. On the surface, the signals are decoded and transmitted to the well-washing control system. Depending on whether the operation is manual or automatic, the system displays the downhole status and provides corresponding operational control. Figure 3 As shown.

[0166] The following table shows the status codes and their corresponding actions:

[0167] Table 2. Relationship between Status Codes and Corresponding Actions

[0168]

[0169] The optional embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details in the above embodiments. Within the scope of the technical concept of the embodiments of the present invention, various simple modifications can be made to the technical solutions of the embodiments of the present invention, and these simple modifications all fall within the protection scope of the embodiments of the present invention.

[0170] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the embodiments of the present invention will not describe the various possible combinations separately.

[0171] Those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware. This program is stored in a storage medium and includes several instructions to cause a microcontroller, chip, or processor to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0172] Furthermore, various different implementations of the present invention can be combined arbitrarily, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed in the present invention.

Claims

1. An oilfield downhole camera system, wherein an oil well casing (13) is installed inside the oil well in the oilfield, and a tubing string (12) capable of vertically moving inside the oil well casing (13) is installed on the oil well casing (13), characterized in that, The system includes: A hollow protective tube (1) is vertically installed inside the tubing string (12). The hollow protective tube (1) is connected to the tubing string (12) through a connector (11) and can move vertically inside the well casing (13) along with the tubing string (12). The imaging device (2) is installed at the bottom of the hollow protective tube (1) and is used to capture images of the inside of the oil well. The signal transmitting device (3) is located at the top of the hollow protective tube (1) and connected to the shooting device (2) for transmitting the acquired images inside the oil well; The signal receiving device (4) is connected to the tubing valve (121) located at the top of the tubing string (12) and is used to receive images inside the well. The liquid injection device (5) is connected to the oil pipe valve (121) at its outlet and is used to inject liquid into the hollow protective pipe (1). The return fluid treatment device (6) is connected to the annular valve (131) at the top of the oil well casing (13) for treating the return fluid from the oil well. The system also includes: A hollow and sealed protective shell (7) is installed inside the hollow protective tube (1) by a shock-absorbing device (8). The imaging device (2) is located inside the protective shell (7). A transparent window (71) is provided at the bottom end of the protective shell (7). The imaging device (2) takes pictures of the inside of the oil well through the transparent window (71). A retaining ring (14) is provided inside the bottom end of the hollow protective tube (1) to prevent the protective shell (7) from detaching from the hollow protective tube (1). A ranging device (24) is installed inside the bottom of the protective shell (7) to obtain the distance between the protective shell (7) and the object in the oil well through the transparent window (71); A pressure detection device (25) is installed on the protective housing (7) to obtain the pressure value inside the oil well; A temperature detection device (26) is installed on the protective housing (7) to obtain the temperature value inside the oil well.

2. The oilfield downhole camera system according to claim 1, characterized in that, The shock absorption device (8) includes: Multiple shock-absorbing springs are spaced apart on the outer wall of the protective shell (7). One end of each shock-absorbing spring is fixed to the outer wall of the protective shell (7), and the other end is fixed to the inner wall of the hollow protective tube (1).

3. The oilfield downhole camera system according to claim 2, characterized in that, The shock-absorbing spring is a conical spring, with the small end of each conical spring fixed on the outer wall of the protective shell (7) and the large end fixed on the inner wall of the hollow protective tube (1).

4. The oilfield downhole camera system according to claim 1, characterized in that, The system also includes: An illumination device (21) is provided at the bottom of the protective housing (7) to provide supplementary lighting when the shooting device (2) takes pictures.

5. The oilfield downhole camera system according to claim 4, characterized in that, The lighting device (21) includes: The annular bracket (211) is connected to the bottom of the protective shell (7) via a support rod (212); A lighting lamp (213) is mounted on the annular bracket (211).

6. The oilfield downhole camera system according to claim 1, characterized in that, The system also includes: A power supply device (22) is installed inside the protective housing (7) and connected to the shooting device (2) and the signal transmitting device (3) for supplying power to the shooting device (2) and the signal transmitting device (3).

7. The oilfield downhole camera system according to claim 6, characterized in that, The system also includes: A power generation device (23) is installed inside the top of the hollow protective tube (1) and connected to the power supply device (22). The power generation device (23) generates electricity based on the injected liquid and charges the power supply device (22).

8. The oilfield downhole camera system according to claim 1, characterized in that, The signal transmitting device (3) is a pressure pulse generator, and the signal receiving device (4) is a pressure pulse receiver. The pressure pulse generator uses the liquid injected into the hollow protective tube (1) as the signal transmission medium.

9. The oilfield downhole camera system according to claim 1, characterized in that, The liquid injection device (5) includes: The liquid storage tank (51) is connected to the oil pipe valve (121) through the first pipe (52). The first pipe (52) is equipped with a water pump (53), a flow meter (54) and a pressure gauge (55).

10. The oilfield downhole camera system according to claim 9, characterized in that, The liquid return treatment device (6) includes: A liquid purification tank (61) is connected to the annular valve (131) of the oil well casing (13) via a second pipe (62). A turbidity meter (63) is installed on the liquid purification tank (61). The drain port of the liquid purification tank (61) is connected to the storage tank (51) via a third pipe (64). The sewage outlet of the liquid purification tank (61) is connected to the sewage tank (66) via a fourth pipe (65).

11. The oilfield downhole camera system according to claim 1, characterized in that, The connector (11) is a hollow frustum-shaped connector (11). The large end of the connector (11) is connected to the oil pipe string (12), and the small end is connected to the top of the hollow protective pipe (1).

12. A method for oilfield downhole imaging, implemented using the oilfield downhole imaging system according to any one of claims 1-11, characterized in that, The method includes: As the hollow protective tube inside the tubing string descends with the tubing string, an imaging device captures real-time images of the inside of the well. Simultaneously, a pressure detection device obtains the pressure value at the location of the imaging device, and a temperature detection device obtains the temperature value at the location of the imaging device. When the pressure value is within a first preset pressure range and the temperature value is within a preset temperature range, the shooting device is controlled to stop working; and when the pressure value is within a second preset pressure range, the shooting device is controlled to stop working. The first preset pressure range is greater than the second preset pressure range.

13. The oilfield downhole camera method according to claim 12, characterized in that, The method further includes: If the temperature value is greater than the preset temperature threshold, the liquid injection device is controlled to inject water into the hollow protective tube. The preset temperature threshold is greater than any temperature value in the preset temperature range.

14. The oilfield downhole camera method according to claim 12, characterized in that, The method further includes: Based on real-time acquired images of the interior of the oil well, the clarity of the images is determined. The injection speed of the injection device into the hollow protective pipe is adjusted based on the clarity of the image inside the oil well.

15. The oilfield downhole camera method according to claim 12, characterized in that, The method further includes: The distance between the protective shell and the object inside the oil well is obtained in real time; If the spacing is less than or equal to the preset spacing, the hollow protective tube is controlled to descend at a preset speed; If the spacing is greater than the preset spacing, the hollow protective tube is controlled to stop descending.

Images