UNDERWATER PACKER

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The present disclosure claims the priority of Chinese Invention Application No. CN202411134033.5, filed on Aug. 19, 2024, the entire contents of which are hereby incorporated by reference.

FIELD

The present disclosure relates to an underwater packer.

BACKGROUND

Fixed offshore platforms generally include upper modules and a lower jacket. The jacket provides support for the upper module. A fixing structure of the jacket on the seabed is: a casing is fixed at a bottom of a main jacket leg, and the casing is fixed by steel piles driven into the seabed, and the casing and the steel piles are fixed by injecting cement slurry between the casing and the steel piles. The underwater packer for offshore water has two main functions: 1) to block and seal an annular space between an inner diameter surface of the casing and an outer diameter surface of the steel pile at the bottom of the casing during grouting after the pile driving, preventing the cement slurry from flowing out of the annular space; 2) for the soft soil seabed surface, the packer or a matching device is required to prevent soft soil mud from entering the annular space between the outer diameter surface of the steel pile and the inner diameter surface of the casing during the pile driving, ensuring that the cement slurry is not contaminated.

In the existing technology, many structures of underwater packers are disclosed to solve the above technical problems. For example, the patent with authorization number CN216892418U discloses an improved underwater packer, the patent with authorization number CN216892419U discloses a lotus-shaped underwater packer, and the patent with authorization number CN216892420U discloses an underwater packer having high sealing reliability. These underwater packers have new technical problems: an annular sealing bag is used to pack cement, which prevents the outer pile and the casing from directly contacting the cement slurry, and the connection between the outer pile and the casing is thus not firm enough. How to omit the annular sealing bag and allow the outer pile and the casing to directly contact the cement are newly-researched ideas. At the same time, the inventor considered the need to choose a flap with a suitable length to reduce the cost.

SUMMARY

The purpose of the present disclosure is to disclose an underwater packer. Firstly, the sealing bag is omitted in the present disclosure, and the resin flap has both a load-bearing function and a sealing function, the outer wall of the outer pile and the inner wall of the sleeve are in direct contact with the grouting material, and the connection between the outer pile and the sleeve is thus stronger and more secured. Secondly, the back of the resin flap includes the protrusion, and the inclined surface formed in the top end of the resin flap and the pressing surface of the protrusion abut the inner wall of the outer pile to provide the double-layer sealing with a good sealing effect and the leakage of the grouting material can be avoided. In addition, the present disclosure further includes the sealing cloth and the annular sealing membrane to further improve the sealing effect. When the length of the resin flap is e=(a−0.5c−0.5b)/cos (90°−g), a good sealing of the resin flap can be ensured by inserting the sleeve into the outer pile from any position, and the cost of the resin flap is the lowest.

To achieve the above objectives, the underwater packer provided in the present disclosure includes:

• • an outer pile;
  • a sleeve arranged inside the outer pile;
  • a plug arranged at a bottom end of the sleeve;
  • a grouting pipeline arranged on the sleeve;
  • several resin flaps arranged between the outer pile and the sleeve, and
  • a sealing cloth connected between two adjacent resin flaps through thermal fusion;
  • a bottom end of the resin flap is hinged on a plug, and a top end of the resin flap abuts an inner wall of the outer pile; an annular sealing membrane is connected to a hinge joint of the resin flap through thermal fusion, and a sealing strip is connected to a top end of the sealing cloth through thermal fusion and abuts the inner wall of the outer pile.

In some embodiments, a protrusion is arranged on a back of the resin flap, an inclined surface is formed in a top portion of the resin flap, and a pressing surface of the protrusion is located on an extension surface of the inclined surface.

In some embodiments, a length e of the resin flap is: e≥(a−0.5c−0.5b)/cos (90°−g), wherein a is an inner diameter of the outer pile, b is an outer diameter of the sleeve, c is an outer diameter of the plug, g is an angle between the inclined surface and an extension line of the resin flap within a range of 45°<g<60°.

In some embodiments, an angle between a main body of the resin flap and the protrusion is greater than 90°−g.

In some embodiments, a width of the sealing cloth is ⅕-⅛ of a width of the resin flap.

In some embodiments, a fixing ring is connected to the sleeve, and a hole seat passing through the fixing ring is formed in the bottom end of the resin flap.

In some embodiments, two ends of the annular sealing membrane are respectively connected to the resin flap and the sleeve through thermal fusion.

In some embodiments, the annular sealing membrane is a PVDF membrane or a PTFE membrane.

In some embodiments, both the resin flap and the sleeve are provided with mounting rings, and the two mounting rings are connected by an elastic rope.

In some embodiments, the sealing cloth is polyurethane cloth or polyester cloth.

Compared with the existing technology, the beneficial effects of underwater packer of the present disclosure are as follows.

Firstly, the sealing bag is omitted, and the resin flap has both the load-bearing function and the sealing function. The outer wall of the outer pile and the inner wall of the sleeve are in direct contact with the grouting material, allowing the connection between the outer pile and the sleeve to be more secured.

Secondly, the back of the resin flap includes the protrusion, and the inclined surface formed in the top portion of the resin flap and the pressing surface of the protrusion abut the inner wall of the outer pile to provide the double-layer sealing with a good sealing effect and the leakage of the grouting material can be avoided. In addition, the sealing cloth and the annular sealing membrane can further improve the sealing effect.

Thirdly, when the length e of the resin flap is e=(a−0.5c−0.5b)/cos(90°−g), a good sealing of the resin flap can be ensured by inserting the sleeve into the outer pile from any position, and the cost of the resin flap is the lowest.

BRIEF DESCRIPTION OF THE DRAWINGS

To describe the technical solutions in the embodiments of the present disclosure more clearly, the following briefly introduces the accompanying drawings required for describing the embodiments or the prior art. Apparently, the accompanying drawings in the following description show merely some embodiments of the present disclosure, and persons of ordinary skill in the art may still derive other drawings from these accompanying drawings without creative efforts.

FIG. 1 is a schematic view of an underwater packer according to an embodiment of the present disclosure;

FIG. 2 is a schematic view of a sleeve and a resin flap shown in FIG. 1;

FIG. 3 is an enlarged view of a part A shown in FIG. 2; and

FIG. 4 is a schematic view of the the resin flap shown in FIG. 1.

DETAILED DESCRIPTION

The present disclosure will be described in detail below with reference to the various embodiments shown in the accompanying drawings. However, it should be noted that these embodiments do not limit the present disclosure, and any functional, methodological, or structural equivalent transformations or substitutions made by those skilled in the art based on these embodiments are within the scope of protection of the present disclosure.

An underwater packer shown in FIGS. 1 to 4 includes an outer pile 1, a sleeve 2 arranged inside the outer pile 1, and a plug 4 arranged at a bottom end of the sleeve 2. A bottom end of the outer pile 1 is inserted into the seabed line x, and top ends of both the outer pile 1 and the sleeve 2 exceed the sea surface line y. An annular gap 12 is formed between the outer pile 1 and the sleeve 2, and the sleeve 2 can be inserted into the outer pile 1 from any position, that is, a centerline of the outer pile 1 and a centerline of the sleeve 2 can coincide with each other or not coincide with each other.

The underwater packer further includes several resin flaps 5 arranged between the outer pile 1 and the sleeve 2. The resin flap 5 is an arc plate made of resin material, which is elastic and can be compressed. A bottom end of the resin flap 5 is hinged at the junction of the plug 4 and the sleeve 2. In an embodiment, the sleeve 2 is connected to a fixing ring 9, and a hole seat 91 is formed in the bottom end of the resin flap 5, passing through the fixing ring 9, such that the resin flap 5 can freely rotate around the fixing ring 9.

The resin flap 5 is connected to a hinge joint of an annular sealing membrane 6 through thermal fusion, and two ends of the annular sealing membrane 6 are respectively connected to the resin flap 5 and the sleeve 2 through thermal fusion, providing a sealing effect on the hinge joint of the resin flap 5 and preventing leakage of the grouting material. The annular sealing membrane 6 is a PVDF membrane or a PTFE membrane, which has good elasticity and does not affect the rotation of the resin flap 5.

Two mounting rings 71 are respectively arranged on an inner surface of the resin flap 5 and an outer wall of the sleeve 2. The two mounting rings 71 are connected by an elastic rope 7, such that each resin flap 5 remains in a closed state before the sleeve 2 is inserted into the outer pile 1, which is easy for operation. After the grouting, the elastic rope 7 is stretched, and the resin flap 5 is in an open state.

A top end of the resin flap 5 abuts an inner wall of the outer pile 1, and a protrusion 52 is formed on a back of the resin flap 5. The protrusion 52 is integrally formed with the resin flap 5. An inclined surface 51 is formed in a top portion of the resin flap 5, and a pressing surface 53 of the protrusion 52 is located on an extension surface of the inclined surface 51. The inclined surface 51 in the top portion of the resin flap 5 and the pressing surface 53 of the protrusion 52 both abut the inner wall of the outer pile 1, forming a double-layer sealing having a good sealing effect and avoiding the leakage of the grouting material.

A length e of the resin flap 5 is very important. If the length is too small, the sealing effect may be poor and thus result in the leakage of the grouting material. If the length is too large, the cost may be high. As shown in FIG. 1, by sliding one end of the plug 4 down against the inner wall of the outer pile 1, a minimum length of the resin flap 5 can be calculated with a maximum width of the annular gap 12.

An angle between the resin flap 5 and the horizontal line is f. When f is equal to 90°−g, the inclined surface 51 and the pressing surface 53 are completely pressed against and attached to the inner wall of the outer pile 1, resulting in a good double-layer sealing effect. When f is greater than 90°−g, the inclined surface 51 is partly pressed against and attached to the inner wall of the outer pile 1, and the pressing surface 53 is completely pressed by the inner wall of the outer pile 1, resulting in a good double-layer sealing effect. When f is less than 90°−g, the inclined surface 51 is partly pressed against and attached to the inner wall of the outer pile 1, and the pressing surface 53 is completely separated from the inner wall of the outer pile 1, resulting in a slightly-poor sealing effect.

In summary, in order to achieve a double-layer sealing effect, f≥90°−g is required to be satisfied, then cosf≤cos (90°−g), d/e≤cos (90°−g), and e≥d/cos (90°−g), and thus the length e of the resin flap 5 is: e≥(a−0.5c−0.5b)/cos (90°−g), wherein a is an inner diameter of the outer pile 1, b is an outer diameter of the sleeve 2, c is an outer diameter of the plug 4, g is an angle formed between the inclined surface 51 and an extension line of the resin flap 5 within a range of 45°<g<60°, d is the maximum width of the annular gap 12, and d=□a−□c+□c−□b/2=a−0.5c−0.5b.

The length e of the resin flap 5 is e=(a−0.5c−0.5b)/cos (90°−g), which is the minimum length of the resin flap 5 corresponding to the maximum width of the annular gap 12. The resin flap 5 of this length is also suitable for the annular gap 12 having other widths which meet the condition f>90°−g. Therefore, a good sealing of the resin flap 5 can be ensured by inserting the sleeve 2 into the outer pile 1 from any position, and the cost of the resin flap 5 is the lowest.

An angle between a main body of the resin flap 5 and the protrusion 52 is greater than 90°−g, maintaining a certain distance between the main body of the resin flap 5 and the protrusion 52 and thus providing a space for the deformation of the resin flap 5 and the protrusion 52.

A sealing cloth 8 is connected between two adjacent resin flaps 5 through thermal fusion to avoid affecting the rotation of the resin flap 5. A width of the sealing cloth 8 is 1/7 of a width of the resin flap 5, and the proportion of the sealing cloth 8 is small, which does not affect the overall load-bearing capacity of the underwater packer. The sealing cloth 8 is made of polyurethane cloth or polyester cloth. A top end of the sealing cloth 8 is connected to a sealing strip 81 through thermal fusion. After the grouting, the sealing strip 81 contacts the inner wall of the outer pile 1, ensuring overall sealing and preventing the leakage of the grouting material.

The underwater packer further includes a grouting pipeline 3, which is arranged on an inner wall of the sleeve 2. An outlet of the grouting pipeline 3 is opposite to the inner surface of the resin flap 5, allowing for grouting into the resin flap 5. After the grouting, the grouting material presses the resin flap 5 to flip and seal the annular gap 12.

The resin flap 5 has both a load-bearing function and a sealing function, and the sealing bag can be omitted. The inner wall of the outer pile 1 and the outer wall of the sleeve 2 are directly in contact with the grouting material, and thus the connection between the inner wall of the outer pile 1 and the outer wall of the sleeve 2 is stronger and more secured. After the resin flap 5 is fully opened, a laser rangefinder can be used to detect whether the resin flap 5 is in close contact with the inner wall of the outer pile 1, which improves the success rate of the grouting

The series of detailed explanations listed above are only specific descriptions of the feasible embodiments of the present disclosure, and they are not intended to limit the scope of protection of the present disclosure. Any equivalent embodiments or modifications that do not depart from the spirit of the present disclosure should be included within the scope of protection of the present disclosure.

It is understandable that the above-mentioned technical features may be used in any combination without limitation. The above descriptions are only the embodiments of the present disclosure, which do not limit the scope of the present disclosure. Any equivalent structure or equivalent process transformation made by using the content of the description and drawings of the present disclosure, or directly or indirectly applied to other related technologies in the same way, all fields are included in the scope of patent protection of the present disclosure.