Front suspension

Abstract

The present invention relates to well completion, and provides a front hanger, including a first body that can be connected and fixed to a drill pipe and a second body that can be connected and fixed to a casing built into the drill pipe, the first body and the second body are connected by at least two release screws, each of which is arranged radially, the second body includes a one-way valve that can slide along the axial direction of the first body to cut off each of the release screws, the one-way valve includes a valve body and a plug located in the valve body, the valve body has a channel connecting the outside and the casing, and the plug movably blocks the channel. When the front hanger of the present invention is pressurized, the staff only needs to continuously introduce the pressurized medium into the valve body, which is very simple, and on the other hand, the front hanger is installed in a front manner, and it is located at the front end of the casing and the drill pipe. When the drill pipe and the first body are taken out for well completion, the casing is located at the outermost side of the well completion. At this time, when it needs to be salvaged, the casing can be directly salvaged, which is more convenient.

Description

Technical Field

[0001] The invention relates to well completion, in particular to a front hanger. Background Art

[0002] Whether conventional or unconventional oil and gas horizontal wells, the horizontal section length is generally short, mainly due to the limitations of drilling technology and completion technology. The hanger mainly adopts a post-mounted structure, which is installed at the end of the casing. When necessary, the casing cannot be directly salvaged, and salvage is more troublesome. In addition, when the hanger is pressurized, a small ball needs to be placed in the hanger to form a one-way valve structure. When the hanger is pressurized, the small ball needs to be dissolved, which is more troublesome. Summary of the invention

[0003] The object of the present invention is to provide a front hanger, which is intended to solve the problem that the existing hanger adopts a rear-mounted structure, which affects the casing fishing and is troublesome to hold the pressure.

[0004] The present invention is achieved in that:

[0005] An embodiment of the present invention provides a front hanger, comprising a first body that can be connected and fixed to a drill pipe and a second body that can be connected and fixed to a casing built into the drill pipe, the first body and the second body are connected by at least two release screws, each of the release screws is arranged radially, the second body comprises a one-way valve that can slide along the axial direction of the first body to shear off each of the release screws, the one-way valve comprises a valve body and a plug located in the valve body, the valve body has a channel connecting the outside and the casing, the plug movably blocks the channel.

[0006] Furthermore, the channel has a first flow path that can be connected to the sleeve and a second flow path that can be connected to the outside, the plug is located in the second flow path, and the size of the plug is larger than the caliber of the first flow path, and the caliber of the second flow path is larger than the size of the plug.

[0007] Furthermore, the second body also includes a jacket, the one-way valve is located in the jacket, the bottom of the valve body is provided with a plurality of first water holes connected to the inner side of the jacket, and the jacket is provided with a plurality of second water holes connected to the inner side of the jacket and the outside.

[0008] Furthermore, the valve body has a sliding portion that fits with the inner wall of the outer sleeve, and the sliding portion is provided with a flow channel that radially penetrates and connects to the second flow path. The inner wall of the outer sleeve is provided with a circulation flow path that can be connected to the sleeve, and the circulation flow path is located on the moving path of the flow channel.

[0009] Furthermore, at least one circle of sealing rubber ring is sleeved on the outer surface of the sliding part, and the sealing rubber rings are sequentially spaced apart along the axial direction.

[0010] Furthermore, the second body also includes an inner sleeve that can be connected and fixed to the sleeve, the inner sleeve and the outer sleeve are connected by a bearing, and a safety pin is connected between the inner sleeve and the bearing.

[0011] Furthermore, the outer sleeve is embedded with at least one radially expandable cava on the moving path of the one-way valve, and the cava has a guide surface extending into the outer sleeve and extending axially, the guide surface is inclined inwardly along the moving direction of the valve body, and the valve body has a sliding surface that fits with the guide surface.

[0012] Furthermore, at least one scraper extending outward is provided on the outer surface of the outer sleeve, and the scraper is located at an end of the second body away from the first body.

[0013] Furthermore, there are three scrapers, each of which is evenly distributed around the end of the outer sleeve, and each of the scrapers has a plurality of cutting teeth connected in sequence.

[0014] Furthermore, the connection between the first body and the second body has a correspondingly engaged step structure, and the release screw is provided on the step structure.

[0015] The present invention has the following beneficial effects:

[0016] In the front hanger of the present invention, the first body can be connected to the drill pipe, and the second body can be connected to the casing. When the pressure is suppressed in the one-way valve, it is only necessary to introduce the pressure-suppressing medium into the valve body, and the plug is pushed by the pressure-suppressing medium to block the channel. At this time, after the pressure-suppressing medium is continuously introduced into the valve body, the pressure in the valve body begins to increase to form a pressure-suppressing effect, and when the pressure reaches the zero limit value, the one-way valve can cut off the release screw, thereby separating the first body from the second body. In the above-mentioned pressure-suppressing process, the staff only needs to continue to introduce the pressure-suppressing medium into the valve body, which is very simple. On the other hand, the front hanger is installed in a front manner, and it is located at the front end of the casing and the drill pipe. After the drill pipe and the first body are taken out of the well, the casing is located at the outermost side of the well completion. At this time, when it needs to be salvaged, the casing can be directly salvaged, which is more convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 A schematic diagram of the structure of a front hanger provided in an embodiment of the present invention;

[0019] Figure 2 for Figure 1 A sectional view of a front hanger;

[0020] Figure 3 for Figure 1 The schematic diagram of the structure of the front hanger when the pressure drops suddenly after the front hanger is set and released;

[0021] Figure 4 for Figure 1 Schematic diagram of the structure of the one-way valve of the front suspension. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] See also Figure 1 as well as Figure 2The embodiment of the present invention provides a front hanger 1, comprising a first body 11 and a second body 12, wherein the first body 11 is mainly used to connect and fix with the drill rod 2, and the second body 12 is mainly used to connect and fix with the casing 3, and in this structural form, the casing 3 is located in the drill rod 2, the first body 11 and the second body 12 are located at the same end of the drill rod 2 and the casing 3, and the first body 11 and the second body 12 are connected by at least two release screws 13, and each release screw 13 is arranged in the radial direction, so that The first body 11 and the second body 12 can be connected as a whole through the front hanger 1, wherein the second body 12 includes a one-way valve 14, which can slide along the axial direction of the first body 11 under the action of external force, and then can cut off each release screw 13, so that the first body 11 and the second body 12 are separated, and the one-way valve 14 includes a valve body 141 and a plug 142 located in the valve body 141, and the valve body 141 has a channel connecting the outside and the sleeve 3, and the plug 142 can movably block the channel. In the present invention, when the front hanger 1 is used in well completion, the front hanger 1 is located at the end position in the same direction of the drill pipe 2 and the casing 3, specifically at the front end of the drill pipe 2 and the casing 3. When the pressure is held, the pressure holding medium can be introduced into the valve body 141 of the one-way valve 14, and the pressure starts to be held in the second body 12. The plug 142 is pushed by the pressure holding medium to move in the valve body 141 until the plug 142 blocks the channel, and the channel is blocked. When the pressure continues to be held, the one-way valve 14 is pushed by the pressure holding medium to move along the axial direction of the first body 11 until each release screw 13 is sheared off. At this time, the first body 11 of the front hanger 1 is disconnected from the second body 12, and the drill pipe 2 is separated from the casing 3, and the pressure holding process ends. At this time, due to the release of pressure, the plug 142 automatically falls back to its original position and the channel automatically opens. In the above process, the staff only needs to continuously introduce the pressure-holding medium into the valve body 141. The built-in plug 142 of the one-way valve 14 replaces the traditional ball, and the operation is very simple. On the other hand, since the front hanger 1 is located at the front end of the drill pipe 2 and the casing 3, the drill pipe 2 and the main body of the front hanger 1 can be lifted after the pressure holding is over. At this time, the casing 3 is located at the outermost side of the completion, and the second body 12 of the front hanger 1 is located on the inner side of the completion. When the casing 3 needs to be salvaged, the salvage tool can be directly used to salvage the casing 3 out of the completion, which is more convenient.

[0024] See also Figure 2-Figure 4, optimizing the above embodiment, the channel has a first flow path 143 that can be connected to the sleeve 3 and a second flow path 144 that can be connected to the outside. Of course, the first flow path 143 and the second flow path 144 are in a connected state, and the caliber size of the second flow path 144 is larger than the caliber size of the first flow path 144. The above-mentioned plug 142 is built into the second flow path 144, and the size of the plug 142 is smaller than the caliber of the second flow path 144 and larger than the caliber of the first flow path 143. In this embodiment, the plug 142 also generally adopts a spherical structure. When the pressure-holding medium is introduced into the second flow path 144, the pressure-holding medium can push the plug 142 to move along the second flow path 144 to the first flow path 143. Since the diameter of the first flow path 143 is smaller than the size of the plug 142, the plug 142 can block the first flow path 143, and a pressure-holding effect is formed in the second body 12 of the front suspension 1. When the pressure of the pressure-holding medium is released, the plug 142 can return to the original position of the second flow path 144 through the positive circulation, and the first flow path 143 and the second flow path 144 continue to remain connected. In this structural form, the front suspension 1 adopts a reverse pressure-holding structural form, specifically, the second body 12 includes an outer sleeve 121, the one-way valve 14 is located in the outer sleeve 121, and the bottom of the valve body 141 is provided with a plurality of first water holes 145 connected to the inner side of the outer sleeve 121, and the outer sleeve 121 is provided with a plurality of second water holes 122 connecting the inner side of the outer sleeve 121 with the outside, wherein the first water hole 145 is connected to the second flow path 144, and the first flow path 143, the second flow path 144, the first water hole 145 and the second water hole 122 are arranged in sequence along the axial direction, and the pressure-holding medium enters the outer sleeve 121 from the outside and through the second water hole 122, and then enters the second flow path 144 from the outer sleeve 121 through the first water hole 145, and then pushes the plug 142 in the second flow path 144 to block the first flow path 143. The whole process is just the opposite of the traditional positive pressure holding method, which is from outside to inside. After the pressure holding is completed in this form, the plug 142 can be moved to the end of the second flow path 144 through the positive cycle. At this time, in order to avoid the plug 142 blocking the first water hole 145, a plurality of first water holes 145 are provided. When the plug 142 is located at the bottom of the second flow path 144, at least one or more first water holes 145 remain connected with the inside of the jacket 121. The second water holes 122 are provided with a plurality of them to ensure that the pressure holding medium can smoothly enter the inside of the jacket 121 from the outside. Of course, another structural form can also be adopted, in which the second flow path 144 of the one-way valve 14 is formed by the inner wall of the outer sleeve 121, that is, part of the structure of the one-way valve 14 is an integral whole with the outer sleeve 121, and the first flow path 143 and the second flow path 144 can be separated. When the pressure is built up, the plug 142 continues to block the first flow path 143, and at the same time, the part of the one-way valve 14 corresponding to the first flow path 143 moves axially. In this structure, only the second water hole 122 needs to be provided on the outer sleeve 121, and the first water hole 145 structure is not required.

[0025] See also Figure 2 as well as Figure 3 Furthermore, the valve body 141 has a sliding portion 146 that fits with the inner wall of the outer sleeve 121, and a flow channel 147 that radially penetrates and connects to the second flow path 144 is opened on the sliding portion 146, and a circulating flow path 123 that can be connected to the sleeve 3 is provided on the inner wall of the outer sleeve 121, and the circulating flow path 123 is located on the moving path of the flow channel 147. In this embodiment, after the pressure-holding medium pushes the plug 142 to block the first flow path 143, the pressure-holding medium begins to push the valve body 141 to move vertically upward along the axial direction, and because the sliding portion 146 is in contact with the inner wall of the outer sleeve 121, the inner wall of the outer sleeve 121 forms a blockage for the flow passage 147. When the valve body 141 moves to the circulation flow path 123, the circulation flow path 123, the flow passage 147 and the second flow path 144 are connected in sequence, and the pressure-holding medium in the second flow path 144 enters the sleeve 3 through the flow passage 147 and the circulation flow passage in sequence, and the pressure in the valve body 141 drops suddenly, and the pressure-holding process ends. At this time, the staff does not need to continue to introduce the pressure-holding medium. Of course, before the pressure in the valve body 141 drops suddenly, the movement of the one-way valve 14 has cut off the radially arranged release screws 13, and the first body 11 and the second body 12 of the front suspension 1 have been separated. In addition, at least one circle of sealing rubber ring 148 should be sleeved on the outer surface of the sliding part 146. The sealing rubber rings 148 are distributed in sequence along the axial direction, and usually there are multiple sealing rubber rings 148. Sealing rubber rings 148 are arranged above and below the flow channel 147, so as to ensure the sealing performance around the flow channel 147, so that before the flow channel 147 corresponds to the circulation channel, no pressurized medium in the second flow path 144 will flow out of the flow channel 147, affecting the pressure holding effect in the valve body 141.

[0026] See again Figure 1 as well as Figure 2Further, the second body 12 also includes an inner sleeve 124, which is fixedly connected to the sleeve 3, usually by threaded connection, and the inner sleeve 124 is connected to the outer sleeve 121 by a bearing 125, and a safety pin 126 is connected between the inner sleeve 124 and the bearing 125. In this embodiment, the outer sleeve 121 is connected and fixed to the first body 11 by a release screw 13, and the outer sleeve 121 is connected to the inner sleeve 124 by a bearing 125. Therefore, when the drill rod 2 drives the first body 11 and the outer sleeve 121 to rotate, it will not drive the sleeve 3 to rotate. Of course, when the sleeve 3 rotates, it will not drive the drill rod 2 to rotate, which can reduce the torque load of the release screw 13 before shearing. Usually, at least one scraper 127 extending outward is provided on the outer surface of the outer sleeve 121, and the scraper 127 is located at the end of the second body 12 away from the first body 11. In the process of lowering the drill pipe 2 and the casing 3 to the completion well, if there is a phenomenon of resistance or jamming, the drill pipe 2 can drive the scraper 127 of the outer sleeve 121 to rotate, so as to facilitate the drill pipe 2 and the casing 3 to re-enter the completion well. Since the outer sleeve 121 and the inner sleeve 124 are connected by the bearing 125, the scraper 127 will not drive the casing 3 to rotate when rotating, thereby reducing the torque of the connection structure between the first body 11 and the outer sleeve 121. For the scraper 127, three are usually provided, and each scraper 127 is evenly distributed around the end of the outer sleeve 121, that is, the angle between adjacent scrapers 127 is 120 degrees, and each scraper 127 has a plurality of cutting teeth connected in sequence, and each cutting tooth is a circular arc shallow cone structure with evenly distributed force. The inner wall of the completion well is processed by the rotation of each cutting tooth. Of course, each scraper 127 will not affect the distribution of each second water hole 122. Specifically, the connection between the first body 11 and the second body 12 adopts a corresponding meshing step structure, and the above-mentioned release screw 13 can be inserted into the step structure. Through this mutually meshing step structure, it can enhance the transmission torque between the first body 11 and the second body 12, and improve the rotation function of the front suspension 1. The step structure on the second body 12 is located on the outer sleeve 121.

[0027] See also Figure 1-Figure 3Furthermore, the outer sleeve 121 is embedded with at least one radially expandable slip 15 on the moving path of the one-way valve 14, and each slip 15 has a guide surface 151 extending into the outer sleeve 121 and extending axially, the guide surface 151 is inclined inwardly along the moving direction of the valve body 141, and the valve body 141 has a sliding surface 149 that fits with the guide surface 151. In this embodiment, before the release screw 13 is sheared off, the one-way valve 14 moves axially after the pressure is held. Since the guide surface 151 of the slip 15 is inclined, the diameter of the inner sleeve 121 gradually becomes smaller. When the sliding surface 149 of the valve body 141 moves to the guide surface 151, the valve body 141 can generate an extrusion force on each slip 15 after continuing to move, which can force each slip 15 to move radially toward the outside of the sleeve 121, and make the outer side of each slip 15 protrude from the outer surface of the sleeve 121 and get stuck in the inner wall of the completion, so as to realize the setting of the front hanger 1. This structure can prevent the casing 3 and the second body 12 of the front hanger 1 from being synchronously brought out or displaced when the drill pipe 2 and the first body 11 of the front hanger 1 are lifted out.

[0028] See also Figure 1 as well as Figure 3 For the above structure, after setting, the slip 15 is clamped on the inner wall of the completed well. When the casing 3 needs to be salvaged, the connection structure formed between the slip 15 and the casing 3 should be released first. Since the bearing 125 and the inner sleeve 124 are connected by safety screws, when the casing 3 is salvaged after the pressure is held, the salvage tool can be pressurized by 10t to engage the salvage tool with the outer casing 3. At this time, the salvage tool is lifted up and the hanging weight is detected by the pressure gauge. If the hanging weight increases, the salvage tool is continued to be used. The tool increases the pressure in each casing 3, and then the safety pin 126 used for connecting the innermost inner sleeve 124 and the bearing 125 can be cut off, and the inner sleeve 124 is separated from the innermost outer sleeve 121, thereby removing the obstruction of the slip 15 to the lifting process of the fishing tool. After the stable hanging weight is measured, all the casings 3 can be fished out and completed. Of course, after continuing to pressurize, if the measured hanging weight does not increase, it means that the fishing tool and the outer casing 3 are poorly engaged, and then continue to pressurize 10t to make the two closely contact. When all the casings 3 are pulled out, the outer sleeve 121 of the second body 12 can be left in the completion. Its own length is only 1m and it is located at the bottom of the completion, which will not affect the subsequent operations. Of course, when it needs to be pulled out, the fishing tool can be changed, the outer sleeve 121 of the second body 12 of the front hanger 1 can be washed and fished out of the completion.

[0029] 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, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A front hanger, comprising a first body that can be connected and fixed to a drill pipe and a second body that can be connected and fixed to a casing built into the drill pipe, characterized in that: The first body and the second body are connected by at least two release screws, each of which is arranged radially, and the second body includes a one-way valve that can slide along the axial direction of the first body to cut off each of the release screws, and the one-way valve includes a valve body and a plug located in the valve body, and the valve body has a channel connecting the outside and the sleeve, and the plug movably blocks the channel; The channel has a first flow path that can communicate with the sleeve and a second flow path that can communicate with the outside, the plug is located in the second flow path, and the size of the plug is larger than the caliber of the first flow path, and the caliber of the second flow path is larger than the size of the plug; The second body also includes a jacket, the one-way valve is located in the jacket, the bottom of the valve body is provided with a plurality of first water holes connected to the inner side of the jacket, and the jacket is provided with a plurality of second water holes connected to the inner side of the jacket and the outside; The outer sleeve is fitted with at least one radially expandable slip on the moving path of the one-way valve; The connection between the first body and the second body has a correspondingly engaged step structure, and the release screw is passed through the step structure.

2. The front suspension according to claim 1, characterized in that: The valve body has a sliding portion that fits with the inner wall of the outer sleeve, and the sliding portion is provided with a flow channel that penetrates radially and connects to the second flow path. The inner wall of the outer sleeve is provided with a circulation flow path that can be connected to the sleeve, and the circulation flow path is located on the moving path of the flow channel.

3. The front suspension according to claim 2, characterized in that: At least one circle of sealing rubber ring is sleeved on the outer surface of the sliding part, and the sealing rubber rings are distributed in sequence and at intervals along the axial direction.

4. The front suspension according to claim 1, characterized in that: The second body also includes an inner sleeve that can be connected and fixed to the sleeve, the inner sleeve and the outer sleeve are connected by a bearing, and a safety pin is connected between the inner sleeve and the bearing.

5. The front suspension according to claim 1, characterized in that: The slip has a guide surface extending into the outer sleeve and extending axially, the guide surface is inclined inwardly along the moving direction of the valve body, and the valve body has a sliding surface in contact with the guide surface.

6. The front suspension according to claim 1, characterized in that: At least one scraper extending outward is arranged on the outer surface of the outer sleeve, and the scraper is located at the end of the second body away from the first body.

7. The front suspension according to claim 6, characterized in that: There are three scrapers, each of which is evenly distributed around the end of the outer sleeve, and each of the scrapers has a plurality of cutting teeth connected in sequence.

Images