Novel casing running device sealing structure

Abstract

The utility model discloses a novel sealing structure of a casing running device, which belongs to the technical field of drilling and production equipment, solves the problems that the sealing structure of the casing running device is inconvenient to use and easy to damage, and comprises the casing running device, the casing running device comprises a core shaft at the top end, the bottom end of the core shaft is connected with a bearing sleeve, and the bearing sleeve is connected with the bearing sleeve. A top drive center pipe is installed in the lower casing pipe device and connected with a mandrel and a force bearing sleeve through threads, a sealed containing groove is formed in the force bearing sleeve and is in a cylinder shape, and a sealing structure is installed in the sealed containing groove in the shape of being attached to the inner wall. And a pipe mounting cavity is formed in the sealing structure. The sealing structure is used in the casing running device for drilling and production, sealing is carried out by fitting the inner diameter size, the sealing effect is better, and the specification is more uniform.

Description

Technical Field

[0001] The utility model belongs to the technical field of drilling and mining operation equipment, and specifically relates to a novel sealing structure of a casing lowering device. Background Art

[0002] The casing lowering device is a tool used for casing lowering based on top drive during drilling operations. The sealing structure adopted by the casing lowering device usually consists of a cone guard, a mud sealing sleeve, and a guide cone head. The cone guard is installed at the tail of the lower mandrel, and the guide cone head presses the mud sealing sleeve onto the cone guard. The guide cone head and the cone guard are fastened by a hexagonal cone-end set screw.

[0003] The existing casing running devices at home and abroad all have inner diameter sealing structures for casing circulation mud sealing. Due to the serial differences in casing wall thickness, the seals can only be used in a one-to-one matching manner, which increases the difficulty of matching and makes on-site maintenance and replacement operations more difficult. Moreover, when the wellhead position is offset, the lower core shaft sealing method of the existing casing running device is easily scratched by the internal thread of the coupling when it is introduced into the coupling of the casing, resulting in an extremely short service life of the seal and difficulty in inserting the guide cone. Utility Model Content

[0004] The purpose of the utility model is to:

[0005] In order to solve the problems that the sealing structure of a casing running device in the prior art is inconvenient to use and easy to be damaged, a novel sealing structure of a casing running device is provided.

[0006] The technical solution adopted by the utility model is as follows:

[0007] A novel sealing structure for a casing lowering device comprises a casing lowering device, wherein the casing lowering device comprises a core shaft at the top end, the bottom end of the core shaft is connected to a bearing sleeve, a top drive center pipe is installed in the casing lowering device, the top drive center pipe is connected to the core shaft and the bearing sleeve through threads, a sealing accommodating groove is provided inside the bearing sleeve, the sealing accommodating groove is in a cylindrical shape, a sealing structure is installed in the sealing accommodating groove in a shape that fits the inner wall, and a pipe installation cavity is provided in the sealing structure.

[0008] Furthermore, the sealing structure is connected to the inner wall of the load-bearing sleeve via a thread, the sealing accommodating groove is configured as a stepped groove, and the sealing structure includes a sealing spacer installed at the step of the sealing accommodating groove, and the sealing spacer is connected to a threaded clamping member.

[0009] Furthermore, a layer of mud sealing sleeve is installed on the upper and lower sides of the sealing spacer respectively, and the threaded clamping part is an auxiliary guide sleeve. The cross-section of the auxiliary guide sleeve is convex, and the outer surface of the auxiliary guide sleeve is provided with a guide thread that cooperates with the inner wall of the sealing accommodating groove.

[0010] In summary, due to the adoption of the above technical solution, the beneficial effects of the utility model are:

[0011] The sealing mechanism of the utility model is designed to seal based on the outer diameter of the pipe used in the casing lowering operation. When the casing is inserted into the casing lowering device, the sealing is achieved through the multi-stage limit guide correction and the double-layer layout design of the circulating sealing mechanism. The advantage of this structure is that the outer diameter of the pipe used for casing lowering is consistent, which can reduce the specifications and models of the seals. The existing technology uses sealing based on the inner diameter of the casing pipe. Since the inner wall thickness of the pipe produced by different manufacturers has a variety of specifications, there are many specifications of seals, and the installation and maintenance workload is large. The circulating sealing mechanism of the utility model can achieve effective sealing of the high-pressure mud in the casing lowering operation. Its structure is designed as a double-layer seal, and a spacer ring is designed between the seals to ensure that the double-layer seal does not deform when the circulating mud is working under high pressure, thereby preventing leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a structural diagram of the sealing structure of the utility model in a casing lowering device;

[0013] Figure 2 for Figure 1 A partial enlarged view of the sealing structure at Z in the middle.

[0014] Markings in the figure: 1-mud sealing sleeve, 2-sealing spacer, 3-auxiliary guide sleeve, 4-load-bearing sleeve, 5-core shaft, 6-sealing receiving groove. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail in combination with the embodiments below. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not used to limit the utility model.

[0016] The utility model discloses a novel sealing structure of a casing lowering device, comprising a casing lowering device, wherein the casing lowering device comprises a core shaft 5 at the top end, the bottom end of the core shaft 5 is connected with a bearing sleeve 4, a top drive center pipe is installed in the casing lowering device, the top drive center pipe is connected with the core shaft 5 and the bearing sleeve 4 through threads, a sealing accommodating groove 6 is provided inside the bearing sleeve 4, the sealing accommodating groove 6 is in a cylindrical shape, a sealing structure is installed in the sealing accommodating groove 6 in a shape that fits the inner wall, and a pipe installation cavity is provided in the sealing structure.

[0017] The sealing structure is connected to the inner wall of the load-bearing sleeve 4 through threads, the sealing accommodating groove 6 is set as a stepped groove, and the sealing structure includes a sealing spacer 2 installed at the step of the sealing accommodating groove 6, and the sealing spacer is connected with a threaded clamping piece.

[0018] A layer of mud sealing sleeve 1 is installed on the upper and lower sides of the sealing spacer 2 respectively. The threaded clamping part is an auxiliary guide sleeve 3. The cross-section of the auxiliary guide sleeve 3 is convex. The outer surface of the auxiliary guide sleeve 3 is provided with a guide thread that cooperates with the inner wall of the sealing accommodating groove 6.

[0019] The casing lowering device is installed below the top drive equipment. The main shaft of the bearing sleeve 4 of the casing lowering device is connected to the top drive center pipe in a threaded manner to bear the weight of the cementing casing transmitted by the slip clamping mechanism.

[0020] The sealing structure of the top drive casing device of the utility model adopts a circulating sealing mechanism, which can effectively solve the problem of insufficient strength of the old sealing structure. The sealing mechanism is composed of a mud sealing sleeve 1, a sealing spacer 2 and an auxiliary guide sleeve 3. Among them, the two mud sealing sleeves 1 are separated by the sealing spacer 2, and are installed inside the bearing sleeve 4 through the threaded connection between the auxiliary guide sleeve 3 and the bearing sleeve 4.

[0021] The sealing mechanism of the utility model is designed to seal the outer diameter of the pipe used in the casing lowering operation (i.e., the sealing spacer 2 is sleeved on the outer surface of the pipe, and the pipe passes through the interior of the sealing spacer 2 and is clamped by the clamping mechanism below). When the casing is inserted into the casing lowering device, the sealing is achieved through the multi-stage limit guide correction and the double-layer layout design of the circulating sealing mechanism. The advantage is that the outer diameters of the pipes used in the casing lowering are consistent, which can reduce the specifications and models of the sealing members. The circulating sealing mechanism can achieve effective sealing of the high-pressure mud in the casing lowering operation. The structure is designed as a double-layer seal, and spacer rings are designed between the seals to ensure that the double-layer seal does not deform when the circulating mud is working under high pressure, thereby preventing leakage.

[0022] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A new type of sealing structure for casing running device, characterized in that: The invention comprises a casing lowering device, wherein the casing lowering device comprises a core shaft (5) at the top end, the bottom end of the core shaft (5) is connected to a bearing sleeve (4), a top drive center pipe is installed in the casing lowering device, the top drive center pipe is connected to the core shaft (5) and the bearing sleeve (4) through threads, a sealing receiving groove (6) is provided inside the bearing sleeve (4), the sealing receiving groove (6) is in the shape of a cylinder, a sealing structure is installed in the sealing receiving groove (6) in a shape that fits the inner wall, and a pipe installation cavity is provided in the sealing structure.

2. A new type of casing running device sealing structure according to claim 1, characterized in that: The sealing structure is connected to the inner wall of the load-bearing sleeve (4) via a thread, the sealing accommodating groove (6) is arranged as a stepped groove, and the sealing structure comprises a sealing spacer (2) installed at the step of the sealing accommodating groove (6), and the sealing spacer is connected to a threaded clamping member.

3. A new type of casing running device sealing structure according to claim 2, characterized in that: A layer of mud sealing sleeve (1) is respectively installed on the upper and lower sides of the sealing spacer (2); the threaded pressing member is an auxiliary guide sleeve (3); the cross section of the auxiliary guide sleeve (3) is convex; the outer surface of the auxiliary guide sleeve (3) is provided with a guide thread that matches the inner wall of the sealing receiving groove (6).

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