A heating device for well logging instrument

Abstract

The present invention discloses a heating device for a well logging instrument. The constant temperature chamber has a temperature sensing probe, a non-metallic outer protective shell and a non-metallic inner shell. The non-metallic inner shell is placed inside the non-metallic outer protective shell. An instrument placement bracket is arranged inside the non-metallic inner shell for placing the instrument to be tested. The temperature sensing probe is arranged inside the non-metallic inner shell. The air outlet of the air pressure and temperature control cabinet is connected with the air inlet of the constant temperature chamber, and the air outlet of the constant temperature chamber is connected with the air inlet of the air pressure and temperature control cabinet to form a hot air circulation loop. The air pressure and temperature control cabinet heats the instrument to be tested in the constant temperature chamber through the circulating hot air in the hot air circulation loop. The temperature sensing probe is electrically connected to the air pressure and temperature control cabinet. The device heats the well logging instrument and can maintain a constant temperature in different temperature ranges as needed, which can meet the special requirements of non-magnetic heating test of oil exploration well logging equipment instruments.

Description

Technical Field

[0001] The present invention relates to the field of well logging instrument manufacturing for exploration and development of the petroleum industry, and in particular to a well logging instrument heating device. Background Art

[0002] Well logging instruments are currently commonly used equipment for oil exploration and logging. Usually, temperature changes have a great impact on the measurement results of well logging instruments. The influencing factors include the temperature drift of the electronic circuit and the temperature deformation of the coil system. When calculating the temperature correction coefficient of the instrument, the instrument needs to be heated, and the heating process requires a non-magnetic environment around it.

[0003] At present, the common practices at home and abroad are: first, a heating wire is wound on the outer wall of the non-metallic inner tank, and an insulation layer and a protective shell are arranged outside the heating wire. The instrument is placed in the inner tank, and the inner tank is heated by the heating wire to heat the instrument. Second, the instrument is placed in the non-metallic inner tank, and the inner tank has a circulating heat transfer oil, and the instrument is heated by heating the heat transfer oil.

[0004] The above method has the defects of low heating range, poor heating efficiency, uneven temperature, easy leakage of heat transfer oil, and pollution of environment and instruments. Summary of the invention

[0005] In order to solve the problems of poor heating efficiency and uneven temperature of logging instruments in the prior art, the purpose of the present invention is to provide a logging instrument heating device, which is a heating device that heats the logging instrument under non-magnetic conditions and can maintain a constant temperature in different temperature ranges as needed. It can meet the special requirements of non-magnetic heating tests for oil exploration logging equipment and has the advantages of a wide heating range, uniform temperature, no pollution to the environment or the instrument during the heating process, simple operation and easy maintenance.

[0006] The technical solution of the present invention is:

[0007] A well logging instrument heating device, comprising:

[0008] A constant temperature chamber, wherein the constant temperature chamber has a temperature sensing probe, a non-metallic outer protective shell and a non-metallic inner liner, wherein the non-metallic inner liner is placed inside the non-metallic outer protective shell; an instrument placement bracket is arranged inside the non-metallic inner liner for placing the instrument to be tested; and the temperature sensing probe is arranged inside the non-metallic inner liner;

[0009] and an air pressure and temperature control cabinet, the air outlet of the air pressure and temperature control cabinet is communicated with the air inlet of the constant temperature chamber, the air outlet of the constant temperature chamber is communicated with the air inlet of the air pressure and temperature control cabinet, so as to form a hot air circulation loop; the air pressure and temperature control cabinet heats the tested instrument in the constant temperature chamber through the circulating hot air in the hot air circulation loop; the temperature sensing probe is electrically connected to the air pressure and temperature control cabinet.

[0010] As a further improvement of the present invention, the non-metallic inner liner includes a non-metallic fixing ring and a non-metallic inner liner body, and the non-metallic fixing ring is sleeved on the outside of the non-metallic inner liner body and fixed; the non-metallic fixing ring has multiple air flow channels, and the peripheral surface of the non-metallic inner liner body has mesh holes.

[0011] As a further improvement of the present invention, the materials of the non-metallic inner liner, the non-metallic fixing ring and the non-metallic protective shell are high-temperature resistant fiberglass, ceramics or high-temperature resistant polytetrafluoroethylene; and the non-metallic outer protective shell has an insulation layer.

[0012] As a further improvement of the present invention, the temperature sensing probe includes a first temperature probe, a second temperature probe and a third temperature probe, and the first temperature probe, the second temperature probe and the third temperature probe are respectively arranged at one end, the middle and the other end of the non-metallic inner liner.

[0013] As a further improvement of the present invention, it also includes a first air return pipe, a second air return pipe, an air intake pipe, a flow distribution component and a total air return pipe;

[0014] The air pressure and temperature control cabinet is connected to the middle part of the constant temperature chamber through an air inlet pipe, and the two ends of the constant temperature chamber are respectively connected to a first air return pipe and a second air return pipe, the first air return pipe and the second air return pipe are connected to the flow distribution component, the flow distribution component is connected to the main air return pipe, and the main air return pipe is connected to the air pressure and temperature control cabinet;

[0015] The flow distribution component is connected to an air pressure and temperature control cabinet through a wire; the air pressure and temperature control cabinet controls the flow distribution component according to the test temperature of the temperature sensing probe.

[0016] As a further improvement of the present invention, the diameter of the first air return pipe is larger than that of the second air return pipe.

[0017] As a further improvement of the present invention, the first air return pipe, the second air return pipe and the air inlet pipe are respectively provided with a first telescopic joint, a second telescopic joint and a third telescopic joint in the middle thereof.

[0018] As a further improvement of the present invention, the air pressure and temperature control cabinet includes an air heating box, an air evaporator, a fan, and an air condenser; the air is heated by a heating wire in the air heating box, and heat exchange and cooling are performed through the air evaporator, so the air condenser is placed outside the air pressure and temperature control cabinet, the fan is respectively connected to the air evaporator and the air heating box, and the air evaporator is connected to the air condenser; the outlet of the air heating box is connected to the air condenser.

[0019] As a further improvement of the present invention, a pressure relief assembly is provided at the end of the constant temperature chamber, and the pressure relief assembly includes a pressure relief cover, a rubber belt and a counterweight. The pressure relief cover is in flexible contact with the pressure relief outlet of the constant temperature chamber, and the counterweight is connected to the lower end of the pressure relief cover through the rubber belt; under the gravity of the counterweight, the pressure relief cover closes and seals the pressure relief outlet; when the pressure inside the constant temperature chamber increases, the pressure pushes the pressure relief cover to lift the pressure relief outlet.

[0020] As a further improvement of the present invention, a flexible cable outlet is provided at the end of the constant temperature chamber; the flexible cable outlet is made of high temperature resistant rubber, and the central cable hole of the flexible cable outlet has a pleated contraction structure;

[0021] The constant temperature chamber is arranged on an instrument guide bracket, and a rolling cylindrical structure is arranged on the instrument guide bracket.

[0022] Compared with the prior art, the present invention has the following technical effects:

[0023] The device of the present invention is connected with the air inlet of the air pressure and temperature control cabinet through the air outlet of the constant temperature chamber to form a hot air circulation loop; the air pressure and temperature control cabinet heats the instrument under test in the constant temperature chamber through the circulating hot air in the hot air circulation loop; the temperature sensing probe is electrically connected to the air pressure and temperature control cabinet. The device heats the well logging instrument and can maintain a constant temperature in different temperature ranges as needed, which can meet the special requirements of non-magnetic heating test of oil exploration well logging equipment.

[0024] Furthermore, the air pressure and temperature control cabinet controls the flow distribution component through the set temperature parameters and according to the signal transmitted by the temperature probe through the wire, thereby reducing or increasing the air flow in the first return air duct and the second return air duct, thereby balancing the temperature field in the constant temperature cabin. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is an appearance diagram of a heating device for a well logging instrument in an embodiment of the present invention;

[0026] Figure 2 for Figure 1 The top view after removing the electrical cabinet housing;

[0027] Figure 3 for Figure 1 Partial side view after removing the electrical cabinet housing;

[0028] Figure 4 It is a partial side sectional view;

[0029] Figure 5 A partial schematic diagram for testing a non-metallic liner;

[0030] Figure 6This is a schematic diagram of the pressure relief cover and counterweight;

[0031] Figure 7 It is a cross-sectional view of the pressure relief cover and the counterweight;

[0032] Wherein: the first temperature probe 1, the first telescopic joint 2, the constant temperature chamber 3, the first return air pipe 4, the second temperature probe 5, the air inlet pipe 6, the third temperature probe 7, the second telescopic joint 8, the second return air pipe 9, the third telescopic joint 10, the flow distribution assembly 11, the main return air pipe 12, the air pressure and temperature control cabinet 13, the air heating box 13-1, the air evaporator 13-2, the high temperature resistant fan 13-3, the air condenser 13-4, the first internal return air pipe 3-1, the second internal return air pipe 3-2, the cable flexible outlet 3-4, the non-metallic liner 3-5, the pressure relief assembly 14, the instrument under test 15, the instrument guide bracket 16, the non-metallic fixing ring 3-5-1, the non-metallic liner body 3-5-2, the pressure relief cover 14-1, the rubber belt 14-2, and the counterweight 14-3. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the present invention more clear, the embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other arbitrarily without conflict.

[0034] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0035] The following describes a high-temperature non-sensing heating device for a well logging instrument according to some embodiments of the present invention in conjunction with the accompanying drawings.

[0036] The well logging instrument heating device provided by the present invention is as follows: Figures 1 to 7 As shown, it includes: a constant temperature chamber 3, and an air pressure and temperature control cabinet 13, the constant temperature chamber 3 includes a non-metallic inner liner 3-5, a non-metallic fixing ring 3-5-1 arranged outside the non-metallic inner liner, a non-metallic outer protective shell arranged outside the non-metallic fixing ring, an instrument inlet and outlet end cover, and an instrument guide bracket 16, and the air pressure and temperature control cabinet 13 includes: a heating pipe box, a refrigeration unit, a cold air box, a high temperature resistant fan, a circulation pipeline, and a control cabinet.

[0037] The constant temperature chamber 3 has a temperature sensing probe, a non-metallic outer protective shell and a non-metallic inner liner 3-5, wherein the non-metallic inner liner 3-5 is placed inside the non-metallic outer protective shell; an instrument placement bracket is provided inside the non-metallic inner liner 3-5 for placing the instrument 15 to be tested; the temperature sensing probe is provided inside the non-metallic inner liner 3-5;

[0038] The air outlet of the air pressure and temperature control cabinet 13 is connected to the air inlet of the constant temperature chamber 3, and the air outlet of the constant temperature chamber 3 is connected to the air inlet of the air pressure and temperature control cabinet 13 to form a hot air circulation loop; the air pressure and temperature control cabinet 13 heats the tested instrument 15 in the constant temperature chamber 3 through the circulating hot air in the hot air circulation loop; the temperature sensing probe is electrically connected to the air pressure and temperature control cabinet 13.

[0039] The non-metallic inner liner 3-5 is cylindrical, and is provided with an instrument placement bracket. The temperature sensing probe is provided inside the non-metallic inner liner 3-5, and is used to measure the internal temperature of the non-metallic inner liner, and is connected to the temperature automatic control cabinet. The non-metallic fixing ring 3-5-1 is used to connect the non-metallic inner liner and the non-metallic outer protective shell and is provided with a plurality of ventilation holes. The non-metallic outer protective shell includes an insulation layer.

[0040] The materials of the non-metallic liner, the non-metallic fixing ring and the non-metallic protective shell can be high-temperature resistant glass fiber reinforced plastics, ceramics or high-temperature resistant polytetrafluoroethylene.

[0041] The temperature sensing device and the temperature automatic control device adopt the existing technology and can maintain constant temperature at different temperature points as needed.

[0042] The air pressure and temperature control cabinet 13 is connected to the air inlet pipe 6; Figure 2 The other end of the air inlet pipe 6 is connected to the constant temperature chamber 3, which plays the role of conveying high-pressure, low-temperature or high-temperature air into the constant temperature chamber 3 from the middle; Figure 4 The far end and the proximal end of the constant temperature chamber 3 are respectively connected to the first return air pipe 4 and the second return air pipe 9. Due to the different air transmission distances, the diameter of the first return air pipe 4 is larger than that of the second return air pipe 9 to balance the air transmission flow; the first return air pipe 4 and the second return air pipe 9 are connected to the flow distribution component 11, and the flow distribution component 11 is connected to the air pressure and temperature control cabinet 13 through a wire. The air pressure and temperature control cabinet 13 controls the flow distribution component 11 through the set temperature parameters and according to the signals transmitted by the first temperature probe 1, the second temperature probe 5 and the third temperature probe 7 through the wire, so as to reduce or increase the air flow in the first return air pipe 4 and the second return air pipe 9 respectively, thereby balancing the temperature field in the constant temperature chamber 3.

[0043] In addition, the well logging instrument heating device provided in the above embodiment of the present invention may also have the following additional technical features:

[0044] The heating device of the logging instrument starts with the core structure constant temperature cabin 3, and all parts within a range of 3 meters extending outward are made of non-magnetic materials.

[0045] Optionally, the logging instrument heating device also includes: a first expansion joint 2, a second expansion joint 8 and a third expansion joint 10 are respectively provided in the middle of the first return air pipe 4, the second return air pipe 9 and the air inlet pipe 6, so as to ensure that the sealing of the system remains unchanged and the structure remains stable when the length of the pipeline changes at different working temperatures.

[0046] Optionally, a rolling cylinder structure is added between the constant temperature chamber 3 and its bracket to reduce friction, so that the sealing of the system remains unchanged and the structure remains stable when the pipe length changes at different working temperatures of the constant temperature chamber 3.

[0047] Alternatively, if Figure 3 As shown, the air pressure and temperature control cabinet 13 includes an air heating box 13-1, an air evaporator 13-2, and a fan 13-3. An air condenser 13-4 is arranged outside the air pressure and temperature control cabinet 13. The air is heated by the heating wire in the air heating box 13-1, and heat exchange and refrigeration are performed through the air evaporator 13-2. Since heat needs to be removed to the outside during the refrigeration process, the air condenser 13-4 is placed outside the air pressure and temperature control cabinet 13. The fan 13-3 is a power device for the operation of the system, which inhales air from the main return air pipe 12 and inputs it into the system after pressurization. The fan 13-3 is connected to the air evaporator 13-2 and the air heating box 13-1 respectively, and the air evaporator 13-2 is connected to the air condenser 13-4; the air heating box 13-1 is connected to the outlet of the air condenser 13-4.

[0048] Alternatively, if Figure 4 As shown, the constant temperature chamber 3 includes a non-metallic inner liner 3-5, a first internal return air pipe 3-1, a second internal return air pipe 3-2, and a cable flexible outlet 3-4. The first internal return air pipe 3-1 and the second internal return air pipe 3-2 extend into the constant temperature chamber 3 and are close to the non-metallic inner liner 3-5, which improves the efficiency of collecting return air; the cable flexible outlet 3-4 is made of high temperature resistant rubber, and the central cable hole is designed with a pleated contraction structure, which allows the cable to pass through during instrument testing and prevents operating temperature loss; the instrument 15 being tested is kept in the center of the constant temperature chamber 3 by the centralizer installed on it.

[0049] Alternatively, if Figure 5 As shown, the non-metallic liner 3-5 includes a non-metallic fixing ring 3-5-1 and a non-metallic liner body 3-5-2. The non-metallic fixing ring 3-5-1 and the non-metallic liner body 3-5-2 are rigidly connected by bolts and keys. The non-metallic fixing ring 3-5-1 has multiple air flow channels to reduce air blockage caused by contact with the non-metallic liner body 3-5-2. The non-metallic liner body 3-5-2 has holes on the periphery to form a mesh structure, which not only ensures strength but also helps air circulation.

[0050] Preferably, the outer circumference of the non-metallic fixing ring 3-5-1 is petal-shaped, and a plurality of air flow channels are radially arranged inside, and the non-metallic liner body 3-5-2 is installed on the center hole of the non-metallic fixing ring 3-5-1.

[0051] Alternatively, if Figure 5 , 6 As shown, there is a pressure relief assembly 14 at the far end of the constant temperature chamber 3, and the pressure relief assembly 14 includes a pressure relief cover 14-1, a rubber belt 14-2 and a counterweight 14-3. During the system heating process, the pressure of the gas in the constant temperature chamber 3 will increase. The structure of the pressure relief cover 14-1 is as follows Figure 6 and Figure 7 As shown, a part of the pressure relief cover 14-1 is in flexible contact with the pressure relief outlet of the constant temperature chamber 3. Under the gravity of the counterweight 14-3, the pressure relief cover 14-1 plays a closing role. When the pressure inside the constant temperature chamber 3 increases, the pressure pushes the pressure relief cover 14-1 to lift up, and the hot air is discharged. The pressure relief cover 14-1 keeps the pressure inside the constant temperature chamber 3 within a safe range. The counterweight can be processed from natural non-magnetic stone or cast using silicate cement.

[0052] The first installation and use process of the heating device for the assembled logging instrument of the present invention is as follows:

[0053] First, open the instrument access cover, and place the instrument 15 to be tested on the instrument placement bracket therein;

[0054] Install the constant temperature chamber 3 on the instrument guide bracket 16, connect the first return air pipe 4, the second return air pipe 9, the intake pipe 6, the flow distribution component 11 and the main return air pipe 12; after the pipelines are connected, start the air pressure and temperature control cabinet 13 for preheating;

[0055] As the heating progresses, hot air enters the non-metallic inner liner 3-5, and heats the instrument 15 under test in the constant temperature chamber 3. The non-metallic inner liner body 3-5-2 has holes on its periphery to form a mesh structure, which not only ensures strength but also facilitates air circulation.

[0056] During the heating process, the air pressure and temperature control cabinet 13 controls the flow distribution component 11 according to the test temperature of the temperature sensing probe. The flow distribution component 11 reduces or increases the air flow in the first return air pipe 4 and the second return air pipe 9 respectively, playing a role in balancing the temperature field in the constant temperature chamber 3;

[0057] Under the gravity of the counterweight 14-3, the pressure relief cover 14-1 plays a closing role. When the pressure inside the constant temperature chamber 3 increases, the pressure pushes the pressure relief cover 14-1 up, and the hot air is discharged. The pressure relief cover 14-1 keeps the pressure inside the constant temperature chamber 3 within a safe range.

[0058] In the subsequent use process, it is only necessary to place the instrument 15 to be tested on the instrument placement bracket and heat it.

[0059] All articles and references disclosed above, including patent applications and publications, are incorporated herein by reference for all purposes. The term "consisting essentially of..." describing a combination should include the identified elements, ingredients, parts or steps and other elements, ingredients, parts or steps that do not substantially affect the basic novel features of the combination. The use of the terms "comprising" or "including" to describe the combination of elements, ingredients, parts or steps herein also contemplates embodiments that are essentially composed of these elements, ingredients, parts or steps. By using the term "may", it is intended to illustrate that any attribute described that "may" include is optional.

[0060] Multiple elements, ingredients, parts or steps can be provided by a single integrated element, ingredient, part or step. Alternatively, a single integrated element, ingredient, part or step can be divided into separate multiple elements, ingredients, parts or steps. The disclosure "one" or "an" used to describe an element, ingredient, part or step is not intended to exclude other elements, ingredients, parts or steps.

[0061] It should be understood that the above description is for illustration and not for limitation. Many embodiments and many applications beyond the examples provided will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of the present teachings should not be determined with reference to the above description, but rather with reference to the foregoing claims and the full scope of equivalents to which such claims are entitled. For the purpose of comprehensiveness, all articles and references, including disclosures of patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the foregoing claims is not intended to be a waiver of such subject matter, nor should it be considered that the applicant has not considered such subject matter to be part of the disclosed inventive subject matter.

Claims

1. A well logging instrument heating device, characterized in that: include: A constant temperature chamber (3), the constant temperature chamber (3) comprising a temperature sensing probe, a non-metallic outer protective shell and a non-metallic inner liner (3-5), the non-metallic inner liner (3-5) being arranged inside the non-metallic outer protective shell; an instrument placement bracket is arranged inside the non-metallic inner liner (3-5) for placing an instrument (15) to be tested; the temperature sensing probe is arranged inside the non-metallic inner liner (3-5); and an air pressure and temperature control cabinet (13); the air outlet of the air pressure and temperature control cabinet (13) is connected to the air inlet of the constant temperature chamber (3); the air outlet of the constant temperature chamber (3) is connected to the air inlet of the air pressure and temperature control cabinet (13), so as to form a hot air circulation loop; the air pressure and temperature control cabinet (13) heats the instrument (15) under test in the constant temperature chamber (3) by circulating hot air in the hot air circulation loop; and the temperature sensing probe is electrically connected to the air pressure and temperature control cabinet (13).

2. A well logging instrument heating device according to claim 1, characterized in that: The non-metallic inner liner (3-5) comprises a non-metallic fixing ring (3-5-1) and a non-metallic inner liner body (3-5-2); the non-metallic fixing ring (3-5-1) is sleeved on the outside of the non-metallic inner liner body (3-5-2) and fixed; the non-metallic fixing ring (3-5-1) has a plurality of air flow channels, and the non-metallic inner liner body (3-5-2) has mesh holes on its circumferential surface.

3. A well logging instrument heating device according to claim 2, characterized in that: The materials of the non-metallic inner liner (3-5), the non-metallic fixing ring (3-5-1) and the non-metallic protective shell are high-temperature resistant glass fiber reinforced plastics, ceramics or high-temperature resistant polytetrafluoroethylene; and the non-metallic outer protective shell has a heat-insulating layer.

4. A well logging instrument heating device according to claim 1, characterized in that: The temperature sensing probe comprises a first temperature probe (1), a second temperature probe (5) and a third temperature probe (7); the first temperature probe (1), the second temperature probe (5) and the third temperature probe (7) are respectively arranged at one end, the middle and the other end of the non-metallic inner liner (3-5).

5. A well logging instrument heating device according to claim 1, characterized in that: It also includes a first air return pipe (4), a second air return pipe (9), an air intake pipe (6), a flow distribution component (11) and a main air return pipe (12); The air pressure and temperature control cabinet (13) is connected to the middle part of the constant temperature chamber (3) through an air inlet pipe (6); the two ends of the constant temperature chamber (3) are respectively connected to a first return air pipe (4) and a second return air pipe (9); the first return air pipe (4) and the second return air pipe (9) are connected to the flow distribution component (11); the flow distribution component (11) is connected to a main return air pipe (12); and the main return air pipe (12) is connected to the air pressure and temperature control cabinet (13); The flow distribution component (11) is connected to an air pressure and temperature control cabinet (13) via a wire; the air pressure and temperature control cabinet (13) controls the flow distribution component (11) according to the test temperature of the temperature sensing probe.

6. A well logging instrument heating device according to claim 5, characterized in that: The first air return pipe (4) has a larger diameter than the second air return pipe (9).

7. A well logging instrument heating device according to claim 5, characterized in that: A first telescopic joint (2), a second telescopic joint (8) and a third telescopic joint (10) are respectively provided in the middle of the first air return pipe (4), the second air return pipe (9) and the air inlet pipe (6).

8. A well logging instrument heating device according to claim 1, characterized in that: The air pressure and temperature control cabinet (13) comprises an air heating box (13-1), an air evaporator (13-2), a fan (13-3), and an air condenser (13-4); the air is heated by a heating wire in the air heating box (13-1), and heat exchange and cooling are performed by the air evaporator (13-2), so the air condenser (13-4) is placed outside the air pressure and temperature control cabinet (13); the fan (13-3) is respectively connected to the air evaporator (13-2) and the air heating box (13-1); the air evaporator (13-2) is connected to the air condenser (13-4); the outlets of the air heating box (13-1) and the air condenser (13-4) are in communication.

9. A well logging instrument heating device according to claim 1, characterized in that: A pressure relief assembly (14) is provided at the end of the constant temperature chamber (3), and the pressure relief assembly (14) comprises a pressure relief cover (14-1), a rubber belt (14-2) and a counterweight (14-3); the pressure relief cover (14-1) is in flexible contact with the pressure relief outlet of the constant temperature chamber (3), and the counterweight (14-3) is connected to the lower end of the pressure relief cover (14-1) via the rubber belt (14-2); under the action of the gravity of the counterweight (14-3), the pressure relief cover (14-1) closes and seals the pressure relief outlet; when the internal pressure of the constant temperature chamber (3) increases, the pressure pushes the pressure relief cover (14-1) to lift the pressure relief outlet.

10. A well logging instrument heating device according to claim 1, characterized in that: The end of the constant temperature chamber (3) is provided with a flexible cable outlet (3-4); the flexible cable outlet (3-4) is made of high temperature resistant rubber, and the central cable hole of the flexible cable outlet (3-4) has a pleated contraction structure; The constant temperature chamber (3) is arranged on an instrument guide bracket (16), and a rolling cylindrical structure is arranged on the instrument guide bracket (16).

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