open hole compartment packer

Abstract

The open-hole compartmentalized packer has a sealing assembly on the outer wall of the outer tube. The inner part of the outer tube includes a central tube, and an axial bypass channel runs through the entire body between the outer wall of the central tube and the inner wall of the outer tube. The bypass channel has an upper bypass hole and a lower bypass hole at its upper and lower ends, respectively, located above and below the sealing assembly. By providing a bypass channel running through the entire body on the packer, after the packer is seated in the bypassed open hole, a single packing operation can be performed on the entire open-hole horizontal wellbore. This is suitable for wells with long open-hole sections requiring stratified water control and development, offering a short construction cycle and high efficiency.

Description

Technical Field

[0001] This utility model relates to the field of oilfield well completion sand control tools, specifically a naked-hole compartment packer. Background Technology

[0002] Over the past decade, the development and production of open-hole horizontal wells have shown a year-on-year increasing trend, with an average of 300 well operations per year. Open-hole horizontal wells fully expose oil and gas reservoirs, resulting in low flow resistance. Under the same formation conditions, open-hole completions (including branch wells) correspond to higher unobstructed flow rates of oil and gas. For fractured oil and gas reservoirs, open-hole wells can fully expose fractures, significantly reducing development and production costs. In recent years, with the increasing difficulty of extraction, open-hole completion sand control methods have become more complex and diversified, such as segmented filling in open-hole horizontal wells and filling in open-hole branch wells.

[0003] Open-hole wells, lacking casing support, face higher risks of sand production and collapse. Current solutions involve gravel packing, employing bypass screen packing technology for single-pass sand control. Multiple open-hole packers are used to segment different reservoirs, facilitating stratified water control or stratified production in different sections. However, long / ultra-long horizontal wells often face significant leakage and high packing pressure during the packing stage, posing challenges to conventional packing methods. The key to solving this problem lies in achieving precise segmented well completion for sand control and providing support for subsequent segmented oil production. The crucial element of segmented packing is the segmented packer, which must effectively isolate the formation and integrate with the relatively mature horizontal well bypass screen packing system, enabling the completion of the entire horizontal well section packing in a single pass. Summary of the Invention

[0004] This invention aims to solve existing problems by providing a naked-eye compartmentalized packer.

[0005] To achieve the above objectives, the technical solution adopted by this utility model includes an outer tube, the outer wall of which is provided with a sealing component, and the interior of the outer tube also includes a central tube. A plurality of bypass channels are provided between the outer wall of the central tube and the inner wall of the outer tube, which are arranged axially. The bypass channels penetrate the entire body axially, and the upper and lower ends of the bypass channels are respectively provided with an upper bypass hole and a lower bypass hole. The upper bypass hole and the lower bypass hole both penetrate the side wall of the outer tube and are located above and below the sealing component, respectively.

[0006] In some embodiments, the total area of ​​the lower bypass holes is not less than the total area of ​​the upper bypass holes.

[0007] In some embodiments, the total area of ​​the upper bypass hole should not be less than the area at the minimum cross-section of the packer's built-in bypass channel.

[0008] In some embodiments, the outer tube includes a connecting tube I, a setting head, and a rubber sleeve support tube connected sequentially from top to bottom; wherein the outer wall of the rubber sleeve support tube is provided with an expandable rubber sleeve, the side wall of the setting head is provided with a setting pressure transmission hole, the upper end of the setting pressure transmission hole is connected to the interior of the central tube, and the lower end of the setting pressure transmission hole is connected to the upper end of the expandable rubber sleeve.

[0009] In some embodiments, a rubber sleeve valve body assembly, including a valve body ball and a spring, is provided between the lower end of the setting pressure transmission hole and the upper end of the expansion rubber sleeve; the valve body ball presses against the lower end of the setting pressure transmission hole under the elastic force of the upper end of the spring, and the lower end of the spring is fixed on the inner wall of the setting head.

[0010] In some embodiments, the lower end of the setting pressure transmission hole is provided with an internal conical surface that contacts the valve body ball seal.

[0011] In some embodiments, a self-expanding rubber sleeve is also provided on the outer wall of the outer tube below the expandable rubber sleeve.

[0012] In some embodiments, the outer tube further includes a switch connector, and the corresponding position of the central tube is provided with an axially movable switch sleeve, which divides the central tube into two independent parts: an upper section and a lower section.

[0013] A sealing sliding structure is formed between the upper outer wall of the switch sleeve and the lower inner wall of the upper section of the central tube. Several sealing sliding structures are formed between the lower outer wall of the switch sleeve and the upper inner wall of the lower section of the central tube. The lower outer wall of the switch sleeve is also provided with an outwardly protruding switch sleeve boss, and the inner wall of the switch connector is provided with a radially inwardly protruding connector boss corresponding to its diameter.

[0014] The inner wall of the switch sleeve is provided with a structure that is adapted to the shape of the switch tool; when the switch tool lifts the switch sleeve, the switch sleeve boss moves upward with it until the outer wall of the switch sleeve boss contacts the inner wall of the connector boss, forming a sealing sliding structure, thus completing the closure of the bypass channel.

[0015] In some embodiments, the sealing sliding structure is an O-ring.

[0016] Compared with the prior art, this utility model sets a bypass channel through the entire body on the packer. After the packer of the bypass open hole is set, the entire open hole horizontal well can be filled in one filling operation. It is suitable for wells with long open hole sections that require layered water control and layered development. It solves the technical difficulties of not only filling in sections, but also controlling water and developing in layers according to different sections in the filling of open hole horizontal wells. Moreover, it has a short construction cycle and high efficiency.

[0017] The rubber sleeve valve body assembly can control the pressure direction and has a simple and reliable structure; the sealing assembly is made up of an expansion rubber sleeve and a self-expanding rubber sleeve, and has a simple structure and high sealing reliability, which solves the problem of unreliable sealing of conventional rubber sleeves in open hole sections due to irregular well diameter; the switching assembly can control the opening and closing of the bypass channel. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of an embodiment of the present utility model;

[0019] Figure 2 A schematic diagram of the sealing assembly ( Figure 1 (in box A);

[0020] Figure 3 A schematic diagram of the bypass switch assembly ( Figure 1 (B box in the middle);

[0021] Figure 4 This is a schematic diagram of the structure of the rubber sleeve valve body assembly. Figure 1 (in the C box);

[0022] Referring to the attached diagram, the components are: upper connector-1, center tube-2, center tube pressure transmission hole-21, setting boss-22, connecting tube I-3, setting head-4, setting pressure transmission hole-41, expanding rubber sleeve-5, rubber sleeve support tube-6, self-expanding rubber sleeve-7, external connector-8, connecting tube II-9, switch connector-10, connector boss-101, switch sleeve-11, switch sleeve boss-111, connecting tube III-12, lower bypass hole-13, upper bypass hole-14, lower connector-15, valve body ball-16, and spring-17. Detailed Implementation

[0023] The invention will be further described in detail below with reference to embodiments. For ease of description, the direction of the upper connector will be referred to as "upper" and the direction of the lower connector as "lower".

[0024] See Figure 1 , Figure 1 This invention demonstrates an embodiment of the naked-eye compartment filling packer. The packer body includes an upper connector, the lower outer wall of which is connected to an outer tube. The outer tube is composed of, from top to bottom, a connecting tube I, a seat head, a rubber sleeve support tube, an outer connector, a connecting tube II, a switch connector, a connecting tube III, and a lower connector.

[0025] The outer wall of the rubber sleeve support tube in the outer tube is provided with a radially expandable sealing component. In this embodiment, the sealing component includes an expandable rubber sleeve and a self-expanding rubber sleeve from top to bottom.

[0026] The inner wall of the upper connector is also connected to a central tube, which is located inside the outer tube. Several axially arranged bypass channels are formed in the space between the outer wall of the central tube and the inner wall of the outer tube. The upper and lower ends of each bypass channel are respectively provided with an upper bypass hole and a lower bypass hole. The upper bypass hole is located on the side wall of the upper connector, and the lower bypass hole is located on the side wall of connecting pipe III; both are through holes. The upper and lower bypass holes are located above and below the sealing assembly, respectively. The bypass channel starts from the upper bypass hole on the side wall of the upper connector, passes sequentially along the outer wall of the central tube through the internal spaces of connecting pipe I, the setting head, the rubber sleeve support tube, the outer connector, connecting pipe II, the switch connector, and connecting pipe III, and finally terminates at the lower bypass hole; its length almost runs through the entire packer body.

[0027] Preferably, in this embodiment, there are six upper bypass holes and six lower bypass holes. Furthermore, the total area of ​​the lower bypass holes is not less than the total area of ​​the upper bypass holes, and the total area of ​​the upper bypass holes should not be less than the area at the minimum cross-section of the packer's built-in bypass channel to ensure normal operation.

[0028] See Figure 2 Furthermore, the outer wall of the rubber sleeve support tube is provided with an expanding rubber sleeve, preferably a long vulcanized expanding rubber sleeve. The lower inner wall of the setting head is connected to the upper end of the rubber sleeve support tube, the lower end of the setting head contacts the upper end of the expanding rubber sleeve, and the lower end of the expanding rubber sleeve contacts the lower rubber sleeve seat fixed to the rubber sleeve support tube. The side wall of the setting head is provided with a setting pressure transmission hole, and the outer wall of the central tube is provided with a radially outward protruding setting boss. The outer wall of the setting boss fits against the inner wall of the setting head, and the setting boss is provided with a central tube pressure transmission hole that penetrates its side wall. The upper end of the setting pressure transmission hole is laterally connected to the central tube pressure transmission hole of the setting boss to achieve connection to the interior of the central tube. The lower end of the setting pressure transmission hole is downward connected to the upper end of the expanding rubber sleeve.

[0029] See Figure 4 Furthermore, a valve body assembly, including a valve ball and a spring, is provided between the lower end of the setting pressure transmission orifice and the upper end of the expanding rubber sleeve. The lower end of the spring is fixed to the inner wall of the setting head, and the upper end of the spring is connected to the valve ball. Under the action of the spring force, the valve ball pushes upward against the lower end of the setting pressure transmission orifice, which can realize the unidirectional transmission of control pressure. That is, the pressure in the central tube can be transmitted to the inside of the expanding rubber sleeve. The pressure inside the expanding rubber sleeve cannot be leaked under the control of the valve body assembly, keeping the expanding rubber sleeve in the setting state at all times.

[0030] Preferably, the lower end of the setting pressure transmission hole is provided with an internal conical surface that can contact the metal valve body ball seal to improve sealing performance.

[0031] See Figure 2Furthermore, the outer wall of the outer tube below the expandable rubber sleeve is also equipped with a self-expanding rubber sleeve (existing technology), which has the function of self-expanding in the presence of oil / water. When used together, they can achieve a double rubber sleeve structure seal, adding an extra layer of protection to the pressure-bearing seal of the packer and improving the reliability of sealing the open-eye annulus.

[0032] See Figure 3 Furthermore, it also includes a switch assembly. An axially movable switch sleeve is provided at the position of the central tube corresponding to the switch connector, and the switch sleeve divides the central tube into two independent parts: an upper section and a lower section. The switch sleeve includes an upper section with a smaller diameter and a lower section with a larger diameter (switch sleeve boss).

[0033] A sealing sliding structure is provided between the outer wall of the upper section of the switch sleeve and the inner wall of the lower opening of the upper section of the (central tube); due to its small diameter, there is a distance between the outer wall of the upper section of the switch sleeve and the inner wall of the connector boss.

[0034] The lower outer wall of the switch sleeve has a radially outward protruding switch sleeve boss, and correspondingly, the inner wall of the switch connector has a radially inward protruding connector boss. Furthermore, the inner diameter of the connector boss matches / adapts to the outer diameter of the switch sleeve boss, allowing them to form a seal when they come into contact after sliding.

[0035] See Figure 3 The outer wall of the switch sleeve boss and the inner wall of the upper opening of the lower section of the (central tube) are provided with two sealing sliding structures along the axial direction. The above-mentioned multiple sealing sliding structures can ensure that the outer walls of the upper and lower sections of the switch sleeve remain sealed with the upper and lower sections of the (central tube) when the switch sleeve slides axially, thus isolating the internal space of the central tube from the bypass channel.

[0036] Further, see Figure 3 The upper inner wall of the switch sleeve is also provided with a structure that is compatible with the shape of the switch tool, so that the switch tool can apply force in conjunction.

[0037] As a preferred option, see Figure 3 Each sealing sliding structure uses O-rings, preferably two in number, and the O-rings are all located in the annular sealing groove on the outer wall of the switch sleeve.

[0038] Initially, the switch sleeve is located on the limiting step on the inner wall of the upper opening of the lower section of the (central tube). The upper and lower sections of the switch sleeve (two sealing sliding structures) are sealed to the upper and lower sections of the (central tube) respectively. There is a channel space between the outer wall of the upper section of the switch sleeve and the inner wall of the connector boss, so the bypass channel is open at this time.

[0039] When the switch sleeve is lifted using a switching tool, the switch sleeve boss rises accordingly. When the outer wall of the switch sleeve boss contacts the inner wall of the connector boss, a sealing sliding structure is formed (through the first sealing sliding structure); simultaneously, the second sealing sliding structure below remains sealed to the lower section of the (central tube), isolating the internal space of the central tube from the bypass channel. At this point, due to the contact between the sealing surfaces of the outer wall of the switch sleeve boss and the inner wall of the connector boss, the upper and lower sections of the (central tube) are blocked, and the bypass channel is closed.

[0040] In this embodiment, when using it, first... Figure 1 The cylinder is lowered into the well in the initial state shown. Then, the center is sealed using a setting tool. The internal pressure of the central tube is transmitted to the top of the rubber sleeve valve assembly through the pressure transmission hole of the central tube and the setting pressure transmission hole of the setting head. When the pressure reaches the rubber sleeve valve assembly, it first overcomes the spring force to move the valve ball downward, thus opening the pressurization channel. Then, the pressure enters the interior of the expansion rubber sleeve.

[0041] When the pressure reaches the set value, the pressure in the central tube is released from the wellhead, at which point the expanding rubber sleeve begins to work. Simultaneously, under the combined action of the spring force and the internal pressure of the expanding rubber sleeve, the valve body ball moves upward and re-contacts the internal conical surface at the lower end of the setting pressure transmission hole of the setting head, re-sealing and locking the internal pressure of the expanding rubber sleeve, thus maintaining the expanding rubber sleeve in the setting state. At this time, the annulus at the packer's open hole is sealed, and the oil- and water-sensitive self-expanding rubber sleeve at the bottom of the expanding rubber sleeve begins to gradually expand. Because the expansion cycle of the water-sensitive self-expanding rubber sleeve is inaccurate, the construction time needs to be controlled.

[0042] At this point, the bypass channel running through the entire packer body is open. Filling fluid can enter through the upper bypass hole, pass through the entire packer, and then exit through the lower bypass hole, enabling functions such as segmented filling in open-hole horizontal wells and filling in open-hole branch wells. If the bypass channel needs to be closed, a matching switching tool must be lowered in. Using the switching tool, the switching sleeve is moved upwards, causing the sleeve boss to contact the connector boss. The bypass channel is then closed using an O-ring seal.

[0043] In addition, a locking ring is provided at the lower end of the switch sleeve, which can be used in conjunction with the locking groove on the inner wall of the switch connector to ensure the reliability of the bypass channel switch.

[0044] The embodiments of this utility model have been described above with reference to the accompanying drawings and examples. The structures given in the embodiments do not constitute a limitation on this utility model. Those skilled in the art can make adjustments as needed, and various modifications or variations within the scope of the appended claims are all within the scope of protection.

Claims

1. A naked-eye compartmentalized packer, the main body comprising an outer tube, the outer wall of which is provided with a sealing assembly, characterized in that: The outer tube also includes a central tube. Several bypass channels are provided between the outer wall of the central tube and the inner wall of the outer tube along the axis. The bypass channels penetrate the entire body along the axis. The upper and lower ends of the bypass channels are respectively provided with upper bypass holes and lower bypass holes. The upper bypass holes and lower bypass holes both penetrate the side wall of the outer tube and are located above and below the sealing assembly, respectively.

2. The naked-eye compartment packer according to claim 1, characterized in that: The total area of ​​the lower bypass hole shall not be less than the total area of ​​the upper bypass hole; and / or, the total area of ​​the upper bypass hole shall not be less than the area at the minimum cross-section of the packer's built-in bypass channel.

3. The naked-eye compartment packer according to claim 1, characterized in that: The outer tube includes a connecting pipe I, a seat head, and a rubber sleeve support pipe connected in sequence from top to bottom; The outer wall of the rubber sleeve support tube is provided with an expansion rubber sleeve, and the side wall of the setting head is provided with a setting pressure transmission hole. The upper end of the setting pressure transmission hole is connected to the inside of the central tube, and the lower end of the setting pressure transmission hole is connected to the upper end of the expansion rubber sleeve.

4. The naked-eye compartment packer according to claim 3, characterized in that: A rubber sleeve valve body assembly, including a valve body ball and a spring, is provided between the lower end of the setting seal pressure transmission hole and the upper end of the expansion rubber sleeve. The valve body ball is pressed against the lower end of the setting seal pressure transmission hole by the elastic force of the upper end of the spring, and the lower end of the spring is fixed on the inner wall of the setting head.

5. The naked-eye compartment packer according to claim 4, characterized in that: The lower end of the seat pressure transmission hole is provided with an internal conical surface that contacts the ball seal of the valve body.

6. The naked-eye compartment packer according to any one of claims 3-5, characterized in that: A self-expanding rubber cylinder is also provided on the outer wall of the outer tube below the expansion rubber cylinder.

7. The naked-eye compartment packer according to any one of claims 1-5, characterized in that: The outer tube also includes a switch connector, and the corresponding position of the central tube is provided with an axially movable switch sleeve, which divides the central tube into two independent parts: an upper section and a lower section. A sealing sliding structure is formed between the upper outer wall of the switch sleeve and the lower inner wall of the opening of the upper section of the central tube, and several sealing sliding structures are formed between the lower outer wall of the switch sleeve and the upper inner wall of the opening of the lower section of the central tube. The lower outer wall of the switch sleeve is also provided with an outwardly protruding switch sleeve boss, and the inner wall of the switch connector is provided with a radially inwardly protruding connector boss corresponding to its diameter. The inner wall of the switch sleeve is provided with a structure that is adapted to the shape of the switch tool; when the switch tool lifts the switch sleeve, the switch sleeve boss moves upward with it until the outer wall of the switch sleeve boss contacts the inner wall of the connector boss, forming a sealed sliding structure.

8. The naked-eye compartment packer according to claim 7, characterized in that: The sealing sliding structure is an O-ring.

Images