A new sealing device for mid-deep non-interference geothermal bore casing

Abstract

The present invention belongs to the field of geothermal bore casing technology, and discloses a new sealing device for medium-deep non-interference geothermal bore casing, which is provided with a set outer tube and inner tube; a heat collector is installed in the middle position of the sealer at the bottom of the outer tube; a first sealing ball and a second sealing ball are respectively arranged at the upper and lower ends of the new sealing device for non-interference geothermal bore casing of the outer tube; a voltage divider is installed at the bottom of the new sealing device for non-interference geothermal bore casing of the outer tube; and a nozzle is arranged at the bottom of the voltage divider. The effect of preventing the casing from landslides during the lowering operation can be improved. The outer tube is tightly fitted with the sealing thread by expanding the thread after heating, and the expansion has the best sealing effect, which can improve the sealing effect of the bottom of the casing.

Description

Technical Field

[0001] The invention belongs to the technical field of geothermal bore casing, and in particular relates to a new sealing device for mid-deep layer non-interference geothermal bore casing. Background Art

[0002] At present, the casing of medium and deep geothermal holes is high-pressure and corrosion-resistant petroleum casing, so that the hole wall can be treated to prevent collapse during the drilling process and when the hole is completed and the pipe is lowered, ensuring the drilling process and the safe construction of the geothermal hole after completion.

[0003] Through the above analysis, the problems and defects of the existing technology are: the existing casing bottom directly adopts a pipe thread plug device, so the sealing effect is poor under high pressure underground, the construction is difficult, and geothermal hole collapse is easy to occur.

[0004] The difficulty in solving the above problems and defects is: low impact toughness, easy to occur (tolerance out of the ordinary); cannot be reused.

[0005] The significance of solving the above problems and defects is:

[0006] 1. Control the occurrence of (tolerance out of specification) phenomenon;

[0007] 2. Use the method of rapid cooling after tempering to avoid high temperature brittleness and obtain toughness;

[0008] 3. Use the sub-temperature quenching method to effectively improve harmful elements and impurities and improve toughness through incomplete austenitization of steel;

[0009] 4. Reusable. Summary of the invention

[0010] In order to solve the problems existing in the prior art, the present invention provides a new sealing device for mid-deep non-interference geothermal hole casing.

[0011] The present invention is achieved by providing a new sealing device for a mid-deep non-interference geothermal bore casing, which is provided with a set outer tube and an inner tube;

[0012] A new sealing device for geothermal holes without interference is installed in the middle of the sealer at the bottom of the outer pipe;

[0013] A first sealing ball and a second sealing ball are respectively arranged at the upper and lower ends of the non-interference new sealing device;

[0014] A voltage divider mounted on the bottom of the non-interfering new seal;

[0015] The nozzle is arranged at the bottom of the voltage divider.

[0016] Furthermore, a thread is arranged on the outer wall of the outer tube.

[0017] Furthermore, a guide is provided at the top of the bottom of the outer tube, and the guide guides the sleeve downward to be connected with the metal nozzle.

[0018] Furthermore, the inner tube between the first sealing ball and the second sealing ball is provided with a solidifying liquid layer, a slow-setting liquid layer and a displacement liquid layer in sequence from top to bottom.

[0019] Combining all the above technical solutions, the advantages and positive effects of the present invention are as follows:

[0020]

[0021] First, it can improve the effect of preventing the casing from collapsing during the lowering operation. When the casing is in the lowering operation, first install the new sealing device for the non-interference geothermal hole at the bottom of the first lower hole casing, tighten it with the casing thread with a hydraulic pliers, and then start lowering each casing into the hole by threaded connection. The lowering connection should not be too fast, otherwise the hole collapse is most likely to occur.

[0022] There are two reasons for the hole collapse:

[0023] 1. When drilling, the hole has a large inclination, which causes the casing to bend along with the hole during the lowering operation. The inclination is generally controlled at 2-5 degrees.

[0024] 2. The casing becomes heavier as it goes down, and gravity will slowly damage the hole wall, causing the artificial mud hole wall to break and form a landslide.

[0025] Second, the outer tube is tightly fitted with the sealing thread by means of the heated thread expansion, and the expansion achieves the best sealing effect, which can improve the sealing effect of the bottom of the casing.

[0026] BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 It is a structural schematic diagram of a new sealing device for a mid-deep layer non-interference geothermal hole casing provided by an embodiment of the present invention.

[0029] In the figure: 1, thread; 2, first sealing ball; 3, solidifying liquid; 4, retarding liquid; 5, displacement liquid; 6, second sealing ball; 7, voltage divider; 8, metal nozzle. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0031] In view of the problems existing in the prior art, the present invention provides a new sealing device for mid-deep non-interference geothermal bore casing to solve the technical problems in the prior art of poor sealing effect at the bottom of the casing, easy collapse and obstruction, and difficult pipe laying construction. The present invention is described in detail below in conjunction with the accompanying drawings.

[0032] A thread 1 is arranged on the outer wall of the outer pipe. The geothermal hole is affected by underground geological factors and casing operation factors. When the geothermal hole collapses, the solution is: inject the displacement fluid 5 into the casing, start to pressurize 1.0MPA-2.0MPA, so that the displacement fluid 5 reaches the pressure divider 7 after being pressurized, and then the heavy metal nozzle 8 sprays the displacement fluid 5 to flush out the collapsed sand and stone obstacles, and then the collapsed point or obstruction point that is flushed away becomes thin mud and flows back out of the ground. The obstruction point is solved and the casing operation is continued until the designed depth is reached to complete the hole. After the hole is completed, clean water is injected into the casing to pressurize the displacement fluid 5 to completely squeeze out the first sealing ball 2, and then the first sealing ball 2 is dropped into the new sealing device without interference, and then a certain proportion of retarding liquid 4 and solidifying liquid 3 are injected to make it solidify quickly within a certain period of time, and finally the second sealing ball 6 is put into the casing to strengthen the sealing effect and the pipe is lowered to end.

[0033] The guide at the bottom top of the metal outer tube guides the casing downward and is connected to the metal nozzle 8. When the metal nozzle 8 encounters a hole collapse during the casing operation, a displacement fluid 5 is injected into the casing, and the high-pressure displacement fluid 5 is ejected through the nozzle to flush the collapsed sand and stone at the obstructed point, and then flows out of the ground from the bottom to the top through the gap between the casing and the hole; then the casing is continued to be lowered downward to achieve a smooth casing lowering operation, so that the upper end of the new non-interference geothermal new sealing device is installed at the bottom pipe mouth of the casing to exchange heat with the medium, and the gravity presses the sealing new non-interference geothermal new sealing device downward, so that it is tightly combined with the bottom pipe fitting of the casing, and the new non-interference geothermal new sealing device is sealed to conduct heat with the hot rock and soil in the deep geothermal layer through the medium in the metal casing, and the heat on the new non-interference geothermal new sealing device is conducted to the inside of the casing, thereby improving the casing heat exchange effect; the component located at the bottom is made of solid steel, so it has a certain weighting effect on the sinking pipe.

[0034] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A new sealing device for mid-deep non-interference geothermal bore casing, characterized in that: The new sealing device for the mid-deep non-interference geothermal hole casing is provided with a set of outer tube and inner tube; Heat collector, installed in the middle of the sealer at the bottom of the outer tube; The first sealing ball and the second sealing ball are respectively arranged at the upper and lower ends of the new sealing device for the non-interfering geothermal hole casing of the outer tube; A voltage divider mounted at the bottom of the new sealing device for the non-interfering geothermal bore casing of the outer pipe; A nozzle is arranged at the bottom of the voltage divider; The outer wall of the outer tube is provided with a thread; A solidifying liquid layer, a slow-setting liquid layer and a displacement liquid layer are sequentially arranged in the new outer tube sealing device between the first sealing ball and the second sealing ball from top to bottom.

2. The new sealing device for mid-deep non-interference geothermal bore casing according to claim 1 is characterized in that: A guide is arranged on the top of the bottom of the outer tube, and the guide guides the sleeve downward to be connected with the metal nozzle.

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