System for testing heat insulation of inner coating of drill rod

Abstract

The invention provides a system for a heat insulation test of an inner coating of a drill rod, which comprises a heater which is internally provided with a medium and can heat the medium, a heat preservation box, a drill rod to be tested and a step-by-step drilling fluid cooling assembly which is connected with the drill rod to be tested and internally provided with drilling fluid, and the drill rod to be tested is arranged in the heat preservation box. A medium in the heater can enter the heat preservation box and heat the drill rod to be detected, and drilling fluid in the step-by-step drilling fluid cooling assembly can flow through the interior of the drill rod to be detected, then leaves the drill rod to be detected and returns to the interior of the step-by-step drilling fluid cooling assembly again so as to be cooled and stored step by step in the step-by-step drilling fluid cooling assembly. According to the invention, the drilling fluid can be fully cooled and recycled through grading while a heat insulation test is completed indoors.

Description

Technical Field

[0001] The invention relates to the technical field of drill pipe coating thermal insulation testing, in particular to a system for drill pipe inner coating thermal insulation testing. Background Art

[0002] In drilling operations, it is crucial to control the temperature of the drilling fluid to avoid its rapid temperature rise, which directly affects the drilling efficiency. Therefore, it is necessary to control the wellbore circulation temperature.

[0003] At present, the main temperature control method for cooling the drilling fluid in the well is to set a thermal insulation coating on the inner or outer wall of the drill pipe to achieve cooling. The principle is to apply a layer of thermal insulation coating on the inner or outer wall of the drill pipe to reduce the overall thermal conductivity of the drill pipe. Since the drill pipe will contact the well wall during drilling, the coating on the outer wall of the drill pipe is easy to fall off. Therefore, in actual construction, the inner wall coating of the drill pipe is often used for thermal insulation. Since the thermal insulation of the inner wall coating of the drill pipe is in the research and development and preliminary testing stage, there are few systems suitable for indoor testing of the thermal insulation of the inner wall coating of the drill pipe. In some test systems, the drilling fluid has the disadvantages of not being cooled in time and cannot be recycled, which affects the accuracy of the test results. Summary of the invention

[0004] One object of the present invention is to provide a system for thermal insulation testing of coatings inside drill pipes, so that while the thermal insulation test is completed indoors, the drilling fluid can be fully cooled and recycled through grading.

[0005] According to the present invention, a system for thermal insulation testing of coatings inside drill pipes is provided, comprising a heater having a medium inside and capable of heating the medium, a heat preservation box, a drill pipe to be tested, and a step-by-step drilling fluid cooling assembly connected to the drill pipe to be tested and having drilling fluid inside. The drill pipe to be tested is arranged in the heat preservation box, the medium inside the heater can enter the heat preservation box and heat the drill pipe to be tested, the drilling fluid inside the step-by-step drilling fluid cooling assembly can flow through the inside of the drill pipe to be tested, and then leave the drill pipe to be tested and return to the inside of the step-by-step drilling fluid cooling assembly to be cooled and stored step by step therein, so as to realize the recycling of drilling fluid.

[0006] In a preferred embodiment, the drilling fluid step-by-step cooling component includes a first-level drilling fluid cooling storage device connected to the outlet end of the drill pipe to be tested, and a second-level drilling fluid cooling storage device connected to the first-level drilling fluid cooling storage device through a first pipeline, a first solenoid valve is arranged on the first pipeline, and a first liquid level sensor is arranged inside the second-level drilling fluid cooling storage device and is communicatively connected to the first solenoid valve, and the first liquid level sensor is configured to control the opening and closing of the first solenoid valve according to the liquid level inside the second-level drilling fluid cooling storage device.

[0007] In a preferred embodiment, the drilling fluid step-by-step cooling component also includes a tertiary drilling fluid cooling storage device connected to the secondary drilling fluid cooling storage device via a second pipeline, a second solenoid valve is arranged on the second pipeline, and a second liquid level sensor communicatively connected to the second solenoid valve is arranged inside the tertiary drilling fluid cooling storage device, and the second liquid level sensor is configured to control the opening and closing of the second solenoid valve according to the liquid level inside the tertiary drilling fluid cooling storage device.

[0008] In a preferred embodiment, a first temperature sensor is also provided inside the secondary drilling fluid cooling storage device and is communicatively connected to the second solenoid valve. The first temperature sensor is configured to control the opening and closing of the second solenoid valve according to the temperature of the drilling fluid inside the secondary drilling fluid cooling storage device.

[0009] In a preferred embodiment, it also includes a second temperature sensor for detecting the temperature of the medium and a PLC control system that is respectively communicated with the second temperature sensor and the heater. When the second temperature sensor measures that the temperature of the medium in the insulation box is higher than a set temperature range, the PLC control system controls the heater to reduce power. When the second temperature sensor measures that the temperature of the medium in the insulation box is lower than a set temperature range, the PLC control system controls the heater to increase power.

[0010] In a preferred embodiment, it also includes a pressure sensor disposed on the inner wall of the drill pipe to be tested, for detecting the pressure of the drilling fluid.

[0011] In a preferred embodiment, it further comprises a centrifugal pump, which is arranged on a pipeline close to the inlet end of the drill pipe to be tested and is used to pump the drilling fluid in the tertiary drilling fluid cooling storage into the drill pipe to be tested for testing.

[0012] In a preferred embodiment, the centrifugal pump and the pressure sensor are communicatively connected.

[0013] In a preferred embodiment, the primary drilling fluid cooling storage, the secondary drilling fluid cooling storage and the tertiary drilling fluid cooling storage are respectively communicatively connected to the PLC control system.

[0014] In a preferred embodiment, the insulated box is provided with an inlet at the top for injecting the medium, and an outlet at the bottom for discharging the medium, and a valve is provided at the outlet.

[0015] In a preferred embodiment, the primary drilling fluid cooling storage, the secondary drilling fluid cooling storage and the tertiary drilling fluid cooling storage are respectively communicatively connected to the PLC control system.

[0016] The present invention comprises a heater having a medium inside and capable of heating the medium, a heat preservation box, a drill pipe to be tested, and a step-by-step drilling fluid cooling assembly connected to the drill pipe to be tested and having drilling fluid inside. The drill pipe to be tested is arranged in the heat preservation box, the medium inside the heater can enter the heat preservation box and heat the drill pipe to be tested, the drilling fluid inside the step-by-step drilling fluid cooling assembly can flow through the inside of the drill pipe to be tested and then leave the drill pipe to be tested and return to the inside of the step-by-step drilling fluid cooling assembly to be cooled and stored step by step therein. On the one hand, a heat insulation test can be completed indoors, and on the other hand, the drilling fluid can be fully cooled and recycled through graded cooling and storage. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The overall structural diagram of the system for thermal insulation testing of inner coating of drill pipe according to the present invention is schematically shown;

[0018] Figure 2 Another structural schematic diagram of the system for thermal insulation testing of coating inside a drill pipe according to the present invention is schematically shown.

[0019] In the present application, all drawings are schematic drawings, which are only used to illustrate the principles of the present invention and are not drawn according to the actual scale. DETAILED DESCRIPTION

[0020] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention. It should be noted that, in the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other arbitrarily.

[0021] In the description of the present invention, it is necessary to understand that the terms "inside", "outside", "axial" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0022] In the description of the present invention, “plurality” means two or more than two, unless otherwise clearly and specifically defined.

[0023] In the present invention, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] like Figure 1 As shown, the system 100 for thermal insulation testing of inner coating of drill pipe according to the present invention comprises a heater 1 having a medium inside and capable of heating the medium, an insulation box 13, a drill pipe 15 to be tested, and a step-by-step drilling fluid cooling assembly s connected to the drill pipe 15 to be tested and having drilling fluid inside. The drill pipe 15 to be tested is arranged in the insulation box 13, and the medium inside the heater 1 can enter the insulation box 13 and heat the drill pipe 15 to be tested. Optionally, the insulation box 13 is formed into a rectangular parallelepiped, and the drill pipe 15 to be tested is parallel to the axis of the insulation box 13. The inner wall of the drill pipe 15 to be tested is provided with a thermal insulation coating (not shown in the figure), and drilling fluid is passed into the space formed by the inner wall of the drill pipe 15 to be tested. Since the heater 1 can heat the medium inside, so that the temperature of the medium is increased, and the heater 1 is connected to the insulation box 13 through a pipeline, the medium heated by the heater 1 can enter the insulation box 13, so that part of the drill pipe 15 to be tested is immersed in the medium, so that the medium can heat the drill pipe 15 to be tested. The medium described in the present invention is a heating medium, for example, oil.

[0025] The drilling fluid inside the step-by-step cooling assembly s can flow through the inside of the drill pipe to be tested 15. During the process of flowing through the inside of the drill pipe to be tested 15, the drilling fluid can be heated up, and then leave the drill pipe to be tested 15 and return to the inside of the step-by-step cooling assembly s to be cooled and stored step by step. On the one hand, the thermal insulation test can be completed indoors, and on the other hand, the drilling fluid can be fully cooled and recycled through graded cooling and storage.

[0026] In one or more embodiments, the drilling fluid step-by-step cooling component s includes a first-level drilling fluid cooling storage 3 connected to the outlet end of the drill pipe 15 to be tested, and a second-level drilling fluid cooling storage 7 connected to the first-level drilling fluid cooling storage 3 through a first pipeline. The drilling fluid can flow through the first-level drilling fluid cooling storage 3 and the second-level drilling fluid cooling storage 7 in sequence. A first solenoid valve 4 is provided on the first pipeline. A first liquid level sensor 8 is provided inside the second-level drilling fluid cooling storage 7 that is communicatively connected to the first solenoid valve 4. The drilling fluid first enters the first-level drilling fluid cooling storage 3 and is cooled and stored therein. The first liquid level sensor 8 is configured to control the opening and closing of the first solenoid valve 4 according to the internal liquid level of the second-level drilling fluid cooling storage 7.

[0027] In this embodiment, during the test start-up phase, there is no drilling fluid in the primary drilling fluid cooling storage 3, and the cooled drilling fluid in the secondary drilling fluid cooling storage 7 flows into the interior of the drill pipe to be tested 15 through the inlet end of the drill pipe to be tested 15, and leaves from the outlet end of the drill pipe to be tested 15, and enters the primary drilling fluid cooling storage 3 for cooling and storage. At this time, the first solenoid valve 4 is in a closed state. As the cooled drilling fluid in the secondary drilling fluid cooling storage 7 continues to flow out, when the first liquid level sensor 8 in the secondary drilling fluid cooling storage 7 detects that the liquid level in the secondary drilling fluid cooling storage 7 is lower than the set value, a control signal can be sent to the first solenoid valve 4, and the first solenoid valve 4 is controlled to open, so that the drilling fluid in the primary drilling fluid cooling storage 3 that has undergone primary cooling and temperature reduction flows into the secondary drilling fluid cooling storage 7, and undergoes secondary cooling and temperature reduction in the secondary drilling fluid cooling storage 7. When the first liquid level sensor 8 in the secondary drilling fluid cooling storage 7 detects that the liquid level in the secondary drilling fluid cooling storage 7 is higher than the set value, it can send a control signal to the first solenoid valve 4 and control the first solenoid valve 4 to close. After the drilling fluid in the secondary drilling fluid cooling storage 7 is fully cooled, it continues to flow into the drill pipe 15 to be tested.

[0028] In one or more embodiments, the drilling fluid step-by-step cooling component s also includes a tertiary drilling fluid cooling storage 10 connected to the secondary drilling fluid cooling storage 7 through a second pipeline, a second solenoid valve 9 is arranged on the second pipeline, and a second liquid level sensor 11 is arranged inside the tertiary drilling fluid cooling storage 10 and is communicatively connected to the second solenoid valve 9. The second liquid level sensor 11 is configured to control the opening and closing of the second solenoid valve 9 according to the internal liquid level of the tertiary drilling fluid cooling storage 10.

[0029] In this embodiment, during the test start-up phase, there is no drilling fluid in the first-stage drilling fluid cooling storage 3 and the second-stage drilling fluid cooling storage 7, and the cooling drilling fluid in the third-stage drilling fluid cooling storage 10 flows through the three drill pipes to be tested 15, the first-stage drilling fluid cooling storage 3, and the second-stage drilling fluid cooling storage 7 in sequence, and is cooled step by step in the first-stage drilling fluid cooling storage 3 and the second-stage drilling fluid cooling storage 7, and the second solenoid valve 9 is in a closed state. As the cooling drilling fluid in the third-stage drilling fluid cooling storage 10 continues to flow out, when the second liquid level sensor 11 in the third-stage drilling fluid cooling storage 10 detects that the internal liquid level of the third-stage drilling fluid cooling storage 10 is lower than the set value, the second liquid level sensor 11 can send a liquid level sensor to the third-stage drilling fluid cooling storage 10. The second solenoid valve 9 sends a control signal and controls the second solenoid valve 9 to open, so that the drilling fluid in the secondary drilling fluid cooling storage 7 that has undergone secondary cooling and temperature reduction flows into the tertiary drilling fluid cooling storage 10, and undergoes tertiary cooling and temperature reduction in the tertiary drilling fluid cooling storage 7. As the drilling fluid in the secondary drilling fluid cooling storage 7 flows into the tertiary drilling fluid cooling storage 10, when the second liquid level sensor 11 in the tertiary drilling fluid cooling storage 10 detects that the drilling fluid level is higher than the set value, the second liquid level sensor 11 can send a control signal to the second solenoid valve 9 and control the second solenoid valve 9 to close, and the drilling fluid continues to accumulate in the primary drilling fluid cooling storage 3 and the secondary drilling fluid cooling storage 7.

[0030] In one or more embodiments, a first temperature sensor 6 is also provided inside the secondary drilling fluid cooling storage 7 and is communicatively connected to the second solenoid valve 9. The first temperature sensor 6 is configured to control the opening and closing of the second solenoid valve 9 according to the temperature of the drilling fluid inside the secondary drilling fluid cooling storage 7.

[0031] When the first temperature sensor 6 inside the secondary drilling fluid cooling storage 7 detects that the drilling fluid in the secondary drilling fluid cooling storage 7 reaches the set temperature (the set lower temperature) and the liquid level inside the tertiary drilling fluid cooling storage 10 is lower than the set value, the second liquid level sensor 11 can send a control signal to the second solenoid valve 9 and control the second solenoid valve 9 to open, so that the drilling fluid in the secondary drilling fluid cooling storage 7 that has undergone secondary cooling flows into the tertiary drilling fluid cooling storage 10.

[0032] In one or more embodiments, the system 100 for thermal insulation testing of inner coating of drill pipe described in the present invention also includes a second temperature sensor 20 for detecting the temperature of the medium and a PLC control system respectively communicatively connected to the second temperature sensor 20 and the heater 1. When the second temperature sensor 20 measures that the temperature of the medium in the insulation box 13 is higher than the set temperature range, the PLC control system controls the heater 1 to reduce the power. When the second temperature sensor 20 measures that the temperature of the medium in the insulation box 13 is lower than the set temperature range, the PLC control system controls the heater 1 to increase the power, so that the temperature of the medium can be kept within the set range, thereby improving the accuracy of the test, wherein the set temperature range can be set according to the test needs.

[0033] In one or more embodiments, a third temperature sensor 22 is provided inside the drill pipe 15 to be tested, and the difference between the drilling fluid temperature inside the drill pipe 15 to be tested measured by the third temperature sensor 22 and the temperature of the medium in the insulation box 13 measured by the second temperature sensor 20 can be used to analyze and determine the thermal insulation effect of the coating inside the drill pipe.

[0034] In one or more embodiments, the system 100 for testing the thermal insulation of the inner coating of a drill pipe according to the present invention further includes a sealing ring 16, which is sleeved on the outer periphery of the drill pipe 15 to be tested and seals the contact between the drill pipe 15 to be tested and the insulation box 13, thereby preventing leakage of the medium. Specifically, the system 100 for testing the thermal insulation of the inner coating of a drill pipe according to the present invention includes two sealing rings 16 located in the insulation box 13, which are respectively arranged at the contact position between the drill pipe 15 to be tested and the insulation box 13. It should be noted that when performing the test work, the air tightness of the system 100 for testing the thermal insulation of the inner coating of a drill pipe is first checked.

[0035] In one or more embodiments, the insulation box 13 is provided with an inlet 19 for injecting the medium on the side, a valve 2 is provided on the pipe connecting the inlet 19 and the heater 1, and an outlet 17 for discharging the medium is provided on the top, and the outlet 17 is connected to the heater 1 through a pipe, so that the medium can be recycled. On the premise of ensuring good air tightness of the test device, the valve 2 is opened, and then the heated medium is introduced into the insulation box 13, and then the drilling fluid is introduced into the drill pipe 15 to be tested.

[0036] In one or more embodiments, a support 14 is provided at the bottom of the heat preservation box 13. The support 14 includes an arc-shaped support portion and a bottom plate connected to the bottom end of the arc-shaped support portion.

[0037] In the present invention, a bracket 14 is provided at the bottom of the heat preservation box 13, so as to keep the heat preservation box 13 stable and facilitate the smooth conduct of the test.

[0038] In one or more embodiments, the system 100 for thermal insulation testing of inner coating of drill pipes of the present invention further comprises a pressure sensor 21 disposed on the inner wall of the drill pipe 15 to be tested, for detecting the pressure of drilling fluid inside the drill pipe 15 to be tested.

[0039] In one or more embodiments, the system 100 for thermal insulation testing of inner coating of drill pipe described in the present invention also includes a centrifugal pump 12, which is arranged on a pipeline near the inlet end of the drill pipe 15 to be tested, and is used to extract the drilling fluid in the tertiary drilling fluid cooling storage 10 to the drill pipe 15 to be tested for testing.

[0040] In one or more embodiments, the centrifugal pump 12 is in communication with the pressure sensor 21 .

[0041] The centrifugal pump 12 pumps the drilling fluid in the tertiary drilling fluid cooling storage 10 into the drill pipe 15 to be tested. When the pressure sensor 21 inside the drill pipe 15 to be tested detects that the pressure inside the drill pipe 15 to be tested is less than the set range, a control signal can be sent to the centrifugal pump 12 to control it to increase power. When the pressure sensor 21 inside the drill pipe 15 to be tested detects that the pressure in the coated drill pipe 15 to be tested is greater than the set range, a control signal can be sent to the centrifugal pump 12 to control it to reduce power, thereby effectively controlling the pressure inside the coated drill pipe 15, which is beneficial to improving the test accuracy.

[0042] In one or more embodiments, the primary drilling fluid cooling storage 3, the secondary drilling fluid cooling storage 7 and the tertiary drilling fluid cooling storage 10 are respectively connected to the PLC control system for communication, and the PLC control system can remotely adjust the power of the primary drilling fluid cooling storage 3, the secondary drilling fluid cooling storage 7 and the tertiary drilling fluid cooling storage 10.

[0043] In one or more embodiments, a valve 5 is provided at the outlet end of the drill pipe 15 to be tested.

[0044] Although the present invention has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced by equivalents without departing from the scope of the present invention. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A system for thermal insulation testing of coatings inside drill pipes, comprising a heater having a medium inside and capable of heating the medium, an insulation box, a drill pipe to be tested, and a step-by-step drilling fluid cooling assembly connected to the drill pipe to be tested and having drilling fluid inside. The drill pipe to be tested is arranged in the insulation box, the medium inside the heater can enter the insulation box and heat the drill pipe to be tested, and the drilling fluid inside the step-by-step drilling fluid cooling assembly can flow through the inside of the drill pipe to be tested, and then leave the drill pipe to be tested and return to the inside of the step-by-step drilling fluid cooling assembly to be cooled step by step and stored therein.

2. The system for thermal insulation testing of inner coating of drill pipe according to claim 1, It is characterized in that The drilling fluid step-by-step cooling component includes a first-level drilling fluid cooling storage device connected to the outlet end of the drill pipe to be tested, and a second-level drilling fluid cooling storage device connected to the first-level drilling fluid cooling storage device through a first pipeline, a first solenoid valve is arranged on the first pipeline, and a first liquid level sensor is arranged inside the second-level drilling fluid cooling storage device and is communicatively connected to the first solenoid valve, and the first liquid level sensor is configured to control the opening and closing of the first solenoid valve according to the liquid level inside the second-level drilling fluid cooling storage device.

3. The system for thermal insulation testing of inner coating of drill pipe according to claim 2, It is characterized in that The drilling fluid step-by-step cooling component also includes a tertiary drilling fluid cooling storage device connected to the secondary drilling fluid cooling storage device via a second pipeline, a second solenoid valve is arranged on the second pipeline, a second liquid level sensor communicatively connected to the second solenoid valve is arranged inside the tertiary drilling fluid cooling storage device, and the second liquid level sensor is configured to control the opening and closing of the second solenoid valve according to the liquid level inside the tertiary drilling fluid cooling storage device.

4. The system for thermal insulation testing of inner coating of drill pipe according to claim 3, It is characterized in that A first temperature sensor in communication with the second solenoid valve is also provided inside the secondary drilling fluid cooling storage device. The first temperature sensor is configured to control the opening and closing of the second solenoid valve according to the temperature of the drilling fluid inside the secondary drilling fluid cooling storage device.

5. The system for thermal insulation testing of inner coating of drill pipe according to claim 4, It is characterized in that It also includes a second temperature sensor for detecting the temperature of the medium and a PLC control system which is respectively connected to the second temperature sensor and the heater for communication. When the second temperature sensor measures that the temperature of the medium in the insulation box is higher than the set temperature range, the PLC control system controls the heater to reduce power. When the second temperature sensor measures that the temperature of the medium in the insulation box is lower than the set temperature range, the PLC control system controls the heater to increase power.

6. The system for thermal insulation testing of inner coating of drill pipe according to claim 5, It is characterized in that It also includes a pressure sensor arranged on the inner wall of the drill pipe to be tested, which is used to detect the pressure of the drilling fluid.

7. The system for thermal insulation testing of inner coating of drill pipe according to claim 6, It is characterized in that It also includes a centrifugal pump, which is arranged on a pipeline close to the inlet end of the drill pipe to be tested and is used to pump the drilling fluid in the three-stage drilling fluid cooling storage into the drill pipe to be tested for testing.

8. The system for thermal insulation testing of inner coating of drill pipe according to claim 7, It is characterized in that The centrifugal pump is communicatively connected to the pressure sensor.

9. The system for thermal insulation testing of inner coating of drill pipe according to claim 5, It is characterized in that The first-level drilling fluid cooling storage, the second-level drilling fluid cooling storage and the third-level drilling fluid cooling storage are respectively connected to the PLC control system for communication.

10. The system for thermal insulation testing of inner coating of drill pipe according to claim 1, It is characterized in that It also includes a sealing ring, which is sleeved on the outer periphery of the drill rod to be tested and seals the contact between the drill rod to be tested and the heat preservation box.

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