Variable diameter ball seat multi-cluster opening device and method of use thereof

Abstract

The application discloses a variable-diameter ball seat multi-cluster opening device, which comprises an outer cylinder, a sliding sleeve connected to the inner wall of the outer cylinder through a first shear pin, wherein the sliding sleeve is coaxially arranged with the outer cylinder, a variable-diameter ball seat connected to the inner wall of the sliding sleeve through a second shear pin, a soluble ball arranged on one side of the variable-diameter ball seat, a limiting device arranged on the inner wall of the outer cylinder, wherein the limiting device is arranged close to the variable-diameter ball seat, and the limiting device and the soluble ball are arranged on the two sides of the variable-diameter ball seat respectively. The application can complete multi-section sliding sleeve opening by only throwing one soluble ball, can realize the requirement of volume fracturing multi-cluster perforation, does not need to lower a special sliding sleeve opening tool, and has simple opening process, low wellhead risk and simple structure.

Description

Technical Field

[0001] This invention belongs to the technical field of fracturing equipment in the oil and gas development process, specifically relating to a variable diameter ball seat multi-cluster opening device, and also to a method of using the variable diameter ball seat multi-cluster opening device. Background Technology

[0002] Horizontal well volumetric fracturing technology has become the core of breakthroughs in shale oil single-well production. As shale oil horizontal well stimulation has shifted from early staged fracturing to staged multi-cluster fracturing, and further innovated into long horizontal section subdivided volumetric fracturing technology, the fracture density has increased significantly. Multi-cluster perforations with dense fractures and precise control of multi-cluster fractures have become requirements for horizontal well volumetric fracturing stimulation. Existing sliding sleeve technology can perform multi-stage opening, but under multi-cluster perforation requirements, specialized opening tools are needed for step-by-step sliding sleeve opening. Inaccurate sliding sleeve positioning, complex opening procedures, and high wellhead risks prevent the widespread application of sliding sleeve technology in multi-cluster perforation fracturing. Summary of the Invention

[0003] The purpose of this invention is to provide a variable diameter ball seat multi-cluster opening device, which enables multi-cluster fracturing by launching a ball into the opening device.

[0004] Another object of the present invention is to provide a method of using the variable diameter ball seat multi-cluster opening device.

[0005] The first technical solution adopted in this invention is a variable diameter ball seat multi-cluster opening device, including an outer cylinder, a sliding sleeve connected to the inner wall of the outer cylinder by a first shear pin, the sliding sleeve being coaxially arranged with the outer cylinder, a variable diameter ball seat connected to the inner wall of the sliding sleeve by a second shear pin, a soluble ball being arranged on one side of the variable diameter ball seat, and a limiting device being provided on the inner wall of the outer cylinder, the limiting device being arranged close to the variable diameter ball seat.

[0006] The invention is further characterized in that,

[0007] The limiting device and the soluble ball are respectively located on both sides of the variable diameter ball seat.

[0008] The limiting device includes a first stepped surface and a second stepped surface sequentially formed on the inner wall of the outer cylinder. The first stepped surface is located near the variable diameter ball seat, and a large diameter surface is formed on the inner wall of the outer cylinder, which is located between the first stepped surface and the second stepped surface.

[0009] The variable diameter ball seat includes a retaining ring. The outer wall of the retaining ring is connected to the sliding sleeve by a second shear pin. The inner wall of the retaining ring is connected with several bosses along its circumference. Each boss is connected to a support block, and each support block is interlocked with the others.

[0010] The support block includes a connecting block, a connecting groove is provided in the middle of the connecting block, a boss is engaged in the connecting groove, and an insert is fixed to one side of the connecting block, with each insert interlocking with the others.

[0011] The number of support blocks is set to 8, and the 8 support blocks interlock to form a ring.

[0012] Another technical solution adopted in this invention is a method of using the variable diameter ball seat multi-cluster opening device, which is implemented according to the following steps:

[0013] Step 1: Connect the outer cylinder of the variable diameter ball seat multi-cluster opening device to the sleeve and lower it to the designated position;

[0014] Step 2: Pump the soluble ball into the horizontal section of the liquid pump until it reaches the inclined surface of the variable diameter ball seat. Pressurize the wellhead, and the first shear pin is broken. The variable diameter ball seat and the sliding sleeve move as a whole, exposing the communication channel between the fluid flow and the formation at the fracturing port.

[0015] Step 3: Continue to apply pressure. When the sliding sleeve moves to the first step surface of the outer cylinder, it stops moving due to the limit. The second shear pin is cut off, and the soluble ball drives the variable diameter ball seat to continue moving.

[0016] Step 4: After passing the large diameter surface, the variable diameter ball seat reaches the second step surface of the outer cylinder. The variable diameter ball seat stops moving and the soluble ball is continuously compressed. The support block in the variable diameter ball seat starts to climb from the protrusion of the retaining ring and completes the overall expansion. When the inner diameter of the ring formed by multiple support blocks is larger than the outer diameter of the soluble ball, the soluble ball passes through the entire multi-cluster opening device and enters the next stage of the variable diameter ball seat multi-cluster opening device.

[0017] Step 5: Repeat steps 2 to 4 to activate the next stage of the variable diameter ball joint multi-cluster device, thus completing the activation of the variable diameter ball joint multi-cluster device.

[0018] The beneficial effects of this invention are that the variable diameter ball seat multi-cluster opening device can complete the opening of multiple sliding sleeves by simply dropping a soluble ball, which can meet the needs of multi-cluster perforation in volumetric fracturing. It does not require the insertion of a special sliding sleeve opening tool, the opening process is simple to operate, the wellhead risk is low, and the structure is simple. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the variable diameter ball seat multi-cluster opening device (before opening) of the present invention;

[0020] Figure 2 This is a schematic diagram of the structure of the variable diameter ball seat multi-cluster opening device (after opening) of the present invention;

[0021] Figure 3 This is a schematic diagram of the structure of the variable diameter ball seat (before opening) in the multi-cluster opening device of the variable diameter ball seat of the present invention;

[0022] Figure 4 This is a schematic diagram of the structure of the variable diameter ball seat (after opening) in the multi-cluster opening device for variable diameter ball seats of the present invention;

[0023] Figure 5 This is a schematic diagram of the retaining ring structure in the multi-cluster opening device for the variable diameter ball seat of the present invention;

[0024] Figure 6 This is a schematic diagram of the support block in the multi-cluster opening device for variable diameter ball seats of the present invention.

[0025] In the figure, 1. Outer cylinder; 2. Sliding sleeve; 3. First shear pin; 4. Variable diameter ball seat; 5. Second shear pin; 6. Snap ring; 7. First stepped surface; 8. Large diameter surface; 9. Second stepped surface; 10. Fracturing port; 11. Soluble ball; 12. Support block; 12-1. Connecting block; 12-2. Connecting groove; 12-3. Insert; 13. Boss. Detailed Implementation

[0026] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0027] Example 1

[0028] The present invention provides a variable diameter ball seat multi-cluster opening device, such as... Figure 1-2 As shown, the device includes an outer cylinder 1. A sliding sleeve 2 is connected to the inner wall of the outer cylinder 1 via a first shear pin 3. The sliding sleeve 2 is coaxially arranged with the outer cylinder 1. A variable diameter ball seat 4 is connected to the inner wall of the sliding sleeve 2 via a second shear pin 5. A soluble ball 11 is disposed on one side of the variable diameter ball seat 4. A limiting device is provided on the inner wall of the outer cylinder 1, located near the variable diameter ball seat 4. The limiting device and the soluble ball 11 are respectively disposed on both sides of the variable diameter ball seat 4. The variable diameter ball seat 4 is trumpet-shaped, and the soluble ball 11 can push the variable diameter ball seat 4 under pressure.

[0029] Example 2

[0030] This invention relates to a multi-cluster opening device for a variable-diameter ball seat, comprising an outer cylinder 1. A sliding sleeve 2 is connected to the inner wall of the outer cylinder 1 via a first shear pin 3. The sliding sleeve 2 is coaxially arranged with the outer cylinder 1. A variable-diameter ball seat 4 is connected to the inner wall of the sliding sleeve 2 via a second shear pin 5. A soluble ball 11 is disposed on one side of the variable-diameter ball seat 4. A limiting device is provided on the inner wall of the outer cylinder 1, located close to the variable-diameter ball seat 4. The limiting device and the soluble ball 11 are respectively disposed on opposite sides of the variable-diameter ball seat 4. The variable-diameter ball seat 4 is trumpet-shaped, and the soluble ball 11 can push the variable-diameter ball seat 4 under pressure. The limiting device limits the movement of the variable-diameter ball seat 4 and the sliding sleeve 2.

[0031] The limiting device includes a first stepped surface 7 and a second stepped surface 9 sequentially formed on the inner wall of the outer cylinder 1. The first stepped surface 7 is located near the variable diameter ball seat 4. A large-diameter surface 8 is formed on the inner wall of the outer cylinder 1, positioned between the first stepped surface 7 and the second stepped surface 9. The first stepped surface 7 is a stepped surface on the inner wall of the outer cylinder 1, with an inner diameter smaller than that of the outer cylinder 1, thus limiting the sliding sleeve 2. The inner diameter of the first stepped surface 7 is larger than that of the variable diameter ball seat 4. Similarly, the large-diameter surface 8 is a stepped surface on the inner wall of the outer cylinder 1, with an inner diameter larger than that of the outer cylinder 1, facilitating the passage of the soluble ball 11 through which the variable diameter ball seat 4 passes. The second stepped surface 9 is a stepped surface on the inner wall of the outer cylinder 1, with an inner diameter smaller than that of the variable diameter ball seat 4 but larger than that of the soluble ball 11, thus limiting the variable diameter ball seat 4 while allowing the soluble ball 11 to pass through.

[0032] Example 3

[0033] This invention relates to a multi-cluster opening device for a variable-diameter ball seat, comprising an outer cylinder 1. A sliding sleeve 2 is connected to the inner wall of the outer cylinder 1 via a first shear pin 3. The sliding sleeve 2 is coaxially arranged with the outer cylinder 1. A variable-diameter ball seat 4 is connected to the inner wall of the sliding sleeve 2 via a second shear pin 5. A soluble ball 11 is disposed on one side of the variable-diameter ball seat 4. A limiting device is provided on the inner wall of the outer cylinder 1, located close to the variable-diameter ball seat 4. The limiting device and the soluble ball 11 are respectively disposed on opposite sides of the variable-diameter ball seat 4. The variable-diameter ball seat 4 is trumpet-shaped, and the soluble ball 11 can push the variable-diameter ball seat 4 under pressure. The limiting device limits the movement of the variable-diameter ball seat 4 and the sliding sleeve 2.

[0034] The limiting device includes a first stepped surface 7 and a second stepped surface 9 sequentially formed on the inner wall of the outer cylinder 1. The first stepped surface 7 is located near the variable diameter ball seat 4. A large-diameter surface 8 is formed on the inner wall of the outer cylinder 1, positioned between the first stepped surface 7 and the second stepped surface 9. The first stepped surface 7 is a stepped surface on the inner wall of the outer cylinder 1, with an inner diameter smaller than that of the outer cylinder 1, thus limiting the sliding sleeve 2. The inner diameter of the first stepped surface 7 is larger than the outer diameter of the variable diameter ball seat 4. Similarly, the large-diameter surface 8 is a stepped surface on the inner wall of the outer cylinder 1, with an inner diameter larger than that of the outer cylinder 1, facilitating the passage of the soluble ball 11 through which the variable diameter ball seat 4 passes. The second stepped surface 9 is a stepped surface on the inner wall of the outer cylinder 1, with an inner diameter smaller than that of the variable diameter ball seat 4 but larger than the diameter of the soluble ball 11, thus limiting the variable diameter ball seat 4 while allowing the soluble ball 11 to pass through. Figure 3-5 As shown, the variable diameter ball seat 4 includes a retaining ring 6. The outer wall of the retaining ring 6 is connected to the sliding sleeve 2 through a second shear pin 5. The inner wall of the retaining ring 6 is connected with a number of bosses 13 along its circumference. Each boss 13 is connected to a support block 12, and each support block 12 is interlocked with each other.

[0035] The number of support blocks 12 is set to 8, and the 8 support blocks 12 are interlocked to form a ring. The ring limits the position of the soluble ball 11.

[0036] Example 4

[0037] This invention relates to a multi-cluster opening device for a variable-diameter ball seat, comprising an outer cylinder 1. A sliding sleeve 2 is connected to the inner wall of the outer cylinder 1 via a first shear pin 3. The sliding sleeve 2 is coaxially arranged with the outer cylinder 1. A variable-diameter ball seat 4 is connected to the inner wall of the sliding sleeve 2 via a second shear pin 5. A soluble ball 11 is disposed on one side of the variable-diameter ball seat 4. A limiting device is provided on the inner wall of the outer cylinder 1, located close to the variable-diameter ball seat 4. The limiting device and the soluble ball 11 are respectively disposed on opposite sides of the variable-diameter ball seat 4. The variable-diameter ball seat 4 is trumpet-shaped, and the soluble ball 11 can push the variable-diameter ball seat 4 under pressure. The limiting device limits the movement of the variable-diameter ball seat 4 and the sliding sleeve 2.

[0038] The limiting device includes a first stepped surface 7 and a second stepped surface 9 sequentially formed on the inner wall of the outer cylinder 1. The first stepped surface 7 is located near the variable diameter ball seat 4. A large-diameter surface 8 is formed on the inner wall of the outer cylinder 1, positioned between the first stepped surface 7 and the second stepped surface 9. The first stepped surface 7 is a stepped surface on the inner wall of the outer cylinder 1, with an inner diameter smaller than that of the outer cylinder 1, thus limiting the sliding sleeve 2. The inner diameter of the first stepped surface 7 is larger than the outer diameter of the variable diameter ball seat 4. Similarly, the large-diameter surface 8 is a stepped surface on the inner wall of the outer cylinder 1, with an inner diameter larger than that of the outer cylinder 1, facilitating the passage of the soluble ball 11 through which the variable diameter ball seat 4 passes. The second stepped surface 9 is a stepped surface on the inner wall of the outer cylinder 1, with an inner diameter smaller than that of the variable diameter ball seat 4 but larger than the diameter of the soluble ball 11, thus limiting the variable diameter ball seat 4 while allowing the soluble ball 11 to pass through. Figure 3-5 As shown, the variable diameter ball seat 4 includes a retaining ring 6. The outer wall of the retaining ring 6 is connected to the sliding sleeve 2 through a second shear pin 5. The inner wall of the retaining ring 6 is connected with a number of bosses 13 along its circumference. Each boss 13 is connected to a support block 12, and each support block 12 is interlocked with each other.

[0039] The number of support blocks 12 is set to 8, and the 8 support blocks 12 are interlocked to form a ring. The ring limits the position of the soluble ball 11.

[0040] like Figure 6 As shown, the support block 12 includes a connecting block 12-1, with a connecting groove 12-2 in the middle of the connecting block 12-1. A boss 13 is engaged in the connecting groove 12-2, and an insert 12-3 is fixedly connected to one side of the connecting block 12-1. Each insert 12-3 is interlocked with the others. Under pressure, the soluble ball 11 presses against the insert 12-3, forcing the insert 12-3 to drive the connecting block 12-1 out of the boss 13, thus completing the expansion of the diameter of the variable diameter ball seat 4.

[0041] The method of using the variable diameter ball seat multi-cluster opening device of the present invention is specifically implemented according to the following steps:

[0042] Step 1: Connect the outer cylinder 1 of the variable diameter ball seat multi-cluster opening device to the sleeve and lower it to the designated position;

[0043] Step 2: In the horizontal section, the soluble ball 11 is pumped into the inclined position of the variable diameter ball seat 4. The wellhead is pressurized, the first shear pin 3 is broken, the variable diameter ball seat 4 and the sliding sleeve 2 move as a whole, and the fracturing port 10, the communication channel between the fluid flow and the formation, is exposed.

[0044] Step 3: Continue to apply pressure. When the sliding sleeve 2 moves to the first step surface 7 of the outer cylinder 1, it stops moving due to the limit. The second shear pin 5 is cut off, and the soluble ball 11 drives the variable diameter ball seat 4 to continue moving.

[0045] Step 4: The variable diameter ball seat 4 passes through the large diameter surface 8 and reaches the second step surface 9 of the outer cylinder 1. The variable diameter ball seat 4 stops moving and the soluble ball 11 is continuously compressed. The support block 12 in the variable diameter ball seat 4 starts to climb from the boss 13 of the retaining ring 6 and completes the overall expansion. When the inner diameter of the ring formed by multiple support blocks 12 is larger than the outer diameter of the soluble ball 11, the soluble ball 11 passes through the entire multi-cluster opening device and enters the next stage of the variable diameter ball seat multi-cluster opening device.

[0046] Step 5: Repeat steps 2 to 4 to start the next stage of the variable diameter ball seat multi-cluster device, and finally complete the start-up of the variable diameter ball seat multi-cluster device.

[0047] The present invention relates to a variable diameter ball seat multi-cluster opening device, which can complete the opening of multiple sliding sleeves by simply dropping a soluble ball. It can meet the needs of multi-cluster perforation in volumetric fracturing, without the need to lower a special sliding sleeve opening tool. The opening process is simple to operate, has low wellhead risk, and has a simple structure.

Claims

1. A multi-cluster opening device for a variable-diameter ball seat, characterized in that, Includes an outer cylinder (1), the inner wall of the outer cylinder (1) is connected to a sliding sleeve (2) by a first shear pin (3), the sliding sleeve (2) is coaxially arranged with the outer cylinder (1), the inner wall of the sliding sleeve (2) is connected to a variable diameter ball seat (4) by a second shear pin (5), a soluble ball (11) is provided on one side of the variable diameter ball seat (4), and a limiting device is provided on the inner wall of the outer cylinder (1), the limiting device is located near the variable diameter ball seat (4); The limiting device includes a first step surface (7) and a second step surface (9) sequentially opened on the inner wall of the outer cylinder (1). The first step surface (7) is located near the variable diameter ball seat (4). The inner wall of the outer cylinder (1) is provided with a large diameter surface (8), which is located between the first step surface (7) and the second step surface (9). The variable diameter ball seat (4) includes a retaining ring (6), the outer wall of the retaining ring (6) is connected to the sliding sleeve (2) by a second shear pin (5), and the inner wall of the retaining ring (6) is connected with a number of bosses (13) along its circumference. Each boss (13) is connected to a support block (12), and each support block (12) is interlocked with each other. The support block (12) includes a connecting block (12-1), a connecting groove (12-2) is provided in the middle of the connecting block (12-1), the boss (13) is snapped into the connecting groove (12-2), and an insert (12-3) is fixedly connected to one side of the connecting block (12-1), and each insert (12-3) is interlocked with each other; The number of the support blocks (12) is set to 8, and the 8 support blocks (12) are interlocked to form a ring.

2. The variable diameter ball seat multi-cluster opening device according to claim 1, characterized in that, The limiting device and the soluble ball (11) are respectively disposed on both sides of the variable diameter ball seat (4).

3. The method of using the variable diameter ball seat multi-cluster opening device according to claim 1, characterized in that, The specific steps are as follows: Step 1: Connect the outer cylinder (1) of the variable diameter ball seat multi-cluster opening device to the sleeve and lower it to the designated position; Step 2: Pump the soluble ball (11) in the horizontal section to the inclined position of the variable diameter ball seat (4), pressurize the wellhead, break the first shear pin (3), and move the variable diameter ball seat (4) and the sliding sleeve (2) as a whole, exposing the communication channel between the fluid flow and the formation, fracturing port (10). Step 3: Continue to pressurize. When the sliding sleeve (2) moves to the first step surface (7) of the outer cylinder (1), it is stopped by the limit and the second shear pin (5) is cut off. The soluble ball (11) drives the variable diameter ball seat (4) to continue to move. Step 4: The variable diameter ball seat (4) passes through the large diameter surface (8) and reaches the second step surface (9) of the outer cylinder (1). The variable diameter ball seat (4) stops moving and the soluble ball (11) continues to be compressed. The support block (12) in the variable diameter ball seat (4) starts to climb from the boss (13) of the retaining ring (6) and completes the overall expansion. When the inner diameter of the ring formed by multiple support blocks (12) is larger than the outer diameter of the soluble ball (11), the soluble ball (11) passes through the entire multi-cluster opening device and enters the next stage variable diameter ball seat multi-cluster opening device. Step 5: Repeat steps 2 to 4 to start the next stage of the variable diameter ball seat multi-cluster device, and finally complete the start-up of the variable diameter ball seat multi-cluster device.

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