Multi-layer gas reservoir layered mining shaft device capable of achieving equivalent gas lift function

Abstract

The utility model relates to a multi-layer gas reservoir layered mining shaft device capable of achieving an equivalent gas lift function. The multi-layer gas reservoir layered mining shaft device comprises an upper cavity and a lower cavity. The upper cavity is provided with an upper screwed joint, and the lower cavity is provided with a lower screwed joint; a circular tube channel is arranged in the center of the upper cavity and the center of the lower cavity, the part, located between the upper cavity and the lower cavity, of the circular tube channel is open, and hollow meshes penetrating through the side wall are formed in the part, located below the upper cavity, of the circular tube channel; an annular weighting block is clamped in the upper cavity, a connecting rod is arranged between the upper cavity and the lower cavity, the top end of the connecting rod extends into the upper cavity to be connected with the annular weighting block, and the part, clamped in the upper cavity, of the top end of the connecting rod is sleeved with a spring buckle; the bottom end of the extension rod is contacted with the top end of the lower cavity; an annular lifting platform is arranged in the lower cavity, and the annular lifting platform is in sliding connection with the part, below the upper cavity, of the circular pipe channel; a through hole is further formed in the inner side wall of the annular lifting platform; and the part, above the lower cavity, of the circular tube channel is not communicated with the part below the lower cavity. The utility model has a simple structure.

Description

TECHNICAL FIELD

[0001] The utility model relates to the oil and gas field development field, especially a kind of multi-layer gas reservoir separate layer exploitation wellbore device for gas well with the equivalent gas lift function can be realized. BACKGROUND

[0002] In the gas reservoir reservoir reconstruction process, considering operation cost and construction difficulty, multiple gas-bearing intervals are fractured in the gas well fracturing process. Therefore, for multi-layer gas reservoir, when formulating gas reservoir development plan, according to the difference of geological conditions such as formation pressure of each layer, interlayer distance, heterogeneity, it is determined whether to use separate layer exploitation or multi-layer commingling production development mode.

[0003] Multi-layer commingling production is to equivalent multiple gas reservoir layers developed longitudinally through gas well as one layer for combined exploitation. The advantage of this development mode is that it can greatly improve single well production and realize rapid and efficient development of gas field. However, correspondingly, for gas reservoirs not suitable for multi-layer commingling production: (1) multi-layer commingling production can only be developed generally, and the pertinence of each gas layer production allocation design is poor. Under the same work system, some gas layers are in full load or even overload production, and some gas layers have not fully developed production capacity, so the overall development potential of multi-layer gas reservoir is restricted; (2) in the middle and late stages of development, the formation energy and gas flow liquid carrying capacity decrease, and the wellbore starts to accumulate liquid. The wellbore liquid accumulation rate under this development mode is faster than that of separate layer exploitation, the liquid accumulation height is higher, and the wellbore liquid accumulation is more likely to occur, resulting in production decline or water flooding and other production problems. Considering the above two adverse factors, multi-layer commingling production may face the problem of high production but short stable production time.

[0004] Separate layer exploitation means using downhole tools such as packers and bridge plugs to isolate different layers, and using tubing production or oil casing production to develop respectively. Compared with the general development of multi-layer commingling production, separate layer exploitation can design and implement different production systems according to the characteristics of different gas layers, which is beneficial to ensure that each gas layer has reasonable production capacity and longer stable production period. The disadvantage is that this mode requires higher completion mode and quality of gas well, and often needs multiple packers to seat at the same time, which divides the oil casing annulus into multiple spaces. If the annulus area is not unobstructed, the important drainage gas recovery technology of gas lift cannot be implemented smoothly, which affects the normal production of the current production layer.

[0005] In order to overcome the above prior art deficiencies, while considering that fine development is the future development direction of gas field development field, gas reservoir layered production conforms to this development direction, the utility model provides a kind of multi-layer gas reservoir layered production wellbore device for gas well with the function of equivalent gas lift, by introducing other gas layer gas source to reduce the density of liquid column in the tubing above the device, equivalent gas lift effect is realized, the liquid carrying capacity of target gas layer output gas is improved, to solve the problem that packer seat sealing affects gas lift process normal implementation under the current mainstream multi-layer gas reservoir layered production implementation mode, which may cause wellbore fluid accumulation, and ensure gas well stable production. SUMMARY

[0006] The utility model aims at the above problem, and proposes a kind of multi-layer gas reservoir layered production wellbore device with the function of equivalent gas lift.

[0007] The technical scheme of the utility model is as follows:

[0008] A kind of multi-layer gas reservoir layered production wellbore device with the function of equivalent gas lift, including the upper cavity and lower cavity of common center axis;The upper cavity is equipped with upper threaded joint, and lower cavity is equipped with lower threaded joint;The center of the upper cavity and lower cavity is provided with a circular tube passage, the part between the upper cavity and lower cavity of circular tube passage is open section, and the part below the upper cavity of circular tube passage is provided with the hollow mesh of penetrating lateral wall;

[0009] A ring-shaped weight block is clamped in the upper cavity, an interface rod is arranged between the upper cavity and the lower cavity, the top end of the interface rod extends into the upper cavity and is connected with the ring-shaped weight block, and the part of the top end of the interface rod clamped in the upper cavity is sleeved with a spring buckle;The bottom end of the interface rod is in contact with the top end of the lower cavity;

[0010] A ring-shaped lifting platform is arranged in the lower cavity, and the ring-shaped lifting platform is slidably connected with the part below the upper cavity of the circular tube passage;The inner side wall of the ring-shaped lifting platform is also provided with a through hole;The part above the lower cavity of the circular tube passage is not communicated with the part below the lower cavity.

[0011] A passage is arranged on the upper cavity for the interface rod to pass through, the cross section of the passage is inverted trapezoidal, the maximum width of the passage is less than the width of the ring-shaped weight block, and the minimum width is greater than the width of the spring buckle.

[0012] The ring-shaped lifting platform includes two ring-shaped metal plates of the same size and parallel arrangement, a circular ring is arranged between the two ring-shaped metal plates, and a sealing ring is arranged between the circular ring and the two ring-shaped metal plates;The inner side wall of the circular ring is provided with a guide rail groove, and the inner side wall of the circular ring is also provided with a through hole.

[0013] A guide rail is arranged on the outer side wall of the circular tube passage below the upper cavity, and the guide rail is matched with the guide rail groove.

[0014] The circular pipe channel is an equal-diameter circular pipe channel.

[0015] The moving distance of the ring-shaped weight block in the upper cavity is equal to the length of the open section.

[0016] The outer walls of the upper cavity and the lower cavity are cylindrical.

[0017] The circular pipe channel is an equal-diameter circular pipe channel.

[0018] The cross section of the ring-shaped weight block is rectangular.

[0019] The upper threaded joint and the lower threaded joint are both circular pipes with external threads on the surface, and the upper threaded joint is welded with the upper cavity and the lower threaded joint is welded with the lower cavity.

[0020] The technical effect of the utility model lies in:

[0021] (1) The utility model does not involve electrical control system, reduces production cost and reduces fault probability, and guarantees that operation stability and reliability can be maintained in different downhole environments;

[0022] (2) According to the position of the target pay zone, a fluid migration channel connecting a single pay zone and a wellhead can be constructed by using different numbers of packers, and the application effect of multi-layer pressure opening single-layer production is realized;

[0023] (3) The production pipe column is connected in a threaded connection mode, and the connection is reliable and convenient to assemble and disassemble. The device depth can be adjusted by lifting / lowering the production pipe column + supplementing the oil pipe nipple. Under the condition that the packer clamping distance is reasonable, the production layer position can be adjusted without pulling out the pipe column, which greatly reduces the operation cost of the production layer adjustment and enhances the production flexibility and pertinence;

[0024] (4) The utility model controls the upward movement, downward falling or keeping in place of the ring-shaped lifting platform through the mutual relationship between the downward pressure on the ring-shaped lifting platform generated by the accumulated liquid itself above the ring-shaped lifting platform, the upward thrust on the ring-shaped lifting platform generated by the buoyancy of the other gas produced by the gas layer entering the lower cavity through the oil pipe below the ring-shaped lifting platform and the critical pressure of the spring buckle contraction on the connecting rod, and spontaneously realizes the opening and closing of the space communication path above and below the baffle based on the actual state of the downhole environment;

[0025] (5) when the target gas layer produces water seriously and the tubing above the device has obvious liquid accumulation, the pressure on the ring-shaped lifting platform is greater than the thrust, the ring-shaped lifting platform moves downward, and the metal plate on the originally flush ring-shaped lifting platform forms a height difference with the partition plate; in this height difference range, the hollow mesh on the lower cavity corresponding to the circular tube channel no longer communicates the inside of the circular tube with the ring-shaped lifting platform, but communicates the circular tube channel with the wellbore liquid of the target gas layer; since the gas flow rate is greater than the liquid flow rate, the gas accumulated in the lower cavity corresponding to the circular tube channel rapidly overflows into the target gas layer wellbore environment in the production state through the hollow mesh, is mixed with the liquid accumulation, reduces the density of the liquid accumulation, and equivalently improves the liquid carrying capacity of the produced gas of the target gas layer, which is equivalent to taking gas lift measures on the target production layer and realizes spontaneous treatment of the wellbore liquid accumulation problem of the target production layer. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is an initial state isometric view of the utility model.

[0027] Figure 2 It is an initial state front view of the utility model.

[0028] Figure 3 It is an initial state side view of the utility model.

[0029] Figure 4 It is an initial state schematic view of the utility model.

[0030] Figure 5 It is a schematic view of the ring-shaped lifting platform being pushed upward by gas.

[0031] Figure 6 It is a schematic view of the ring-shaped lifting platform descending under the action of liquid gravity.

[0032] The drawings show that: 1, the upper threaded joint; 2, the upper cavity; 3, the circular tube channel; 4, the ring-shaped weight block; 5, the spring buckle; 6, the hollow mesh; 7, the connecting rod; 8, the partition plate; 9, the ring-shaped lifting platform; 10, the guide rail; 11, the lower cavity; 12, the lower threaded joint. DETAILED DESCRIPTION

[0033] Example 1

[0034] A multi-layer gas reservoir separate layer production wellbore device capable of realizing equivalent gas lift function comprises a common center shaft upper cavity 2 and lower cavity 11; the upper cavity 2 is provided with an upper threaded joint 1, and the lower cavity 11 is provided with a lower threaded joint 12; a circular tube channel 3 is arranged at the center of the upper cavity 2 and the lower cavity 11, the part of the circular tube channel 3 between the upper cavity 2 and the lower cavity 11 is an open section, the part of the circular tube channel 3 below the upper cavity 2 is provided with a hollow mesh 6 penetrating through the side wall, as a fluid inlet and outlet channel;

[0035] The upper cavity 2 is provided with a ring-shaped weight 4, an interface rod 7 is arranged between the upper cavity 2 and the lower cavity 11, the top end of the interface rod 7 is connected to the upper cavity 2 and the ring-shaped weight 4, the top end of the interface rod 7 is clamped in the upper cavity 2, and the part of the interface rod 7 clamped in the upper cavity 2 is provided with a spring buckle 5; the bottom end of the interface rod 7 is in contact with the top end of the lower cavity 11;

[0036] The lower cavity 11 is provided with a ring-shaped lifting platform 9, the ring-shaped lifting platform 9 is in sliding connection with the part of the circular pipe channel 3 below the upper cavity 2; the inner side wall of the ring-shaped lifting platform 9 is further provided with a through hole; and the part of the circular pipe channel 3 above the lower cavity 11 is not in communication with the part of the circular pipe channel 3 below the lower cavity 11.

[0037] The specific implementation process of the embodiment is as follows:

[0038] The premise of the self-implementation of the equivalent gas lifting function of the utility model is that at least one layer of the shot reservoir with gas production capacity exists below the target gas layer during use;

[0039] The utility model is lowered to the designed depth; in the initial state, the ring-shaped lifting platform 9 stays in the lower cavity 11, the top end of the ring-shaped lifting platform 9 is kept at the same height as the top surface of the lower cavity 11, the inner side of the ring-shaped lifting platform 9 is in close contact with the circular pipe channel 3, the outer side of the ring-shaped lifting platform 9 is in close contact with the lower cavity 11, and the space above and below the circular pipe channel 3 is not in communication;

[0040] In the initial production stage, the target gas layer has sufficient energy, the high-speed fluid produced by the target gas layer enters the utility model through the oil jacket annulus, the gas carries the high-speed liquid to move upward and reaches the ground; as the production time becomes longer, the energy of the target gas layer decays, the flow speed of the high-speed fluid produced by the target gas layer slows down, the gas liquid carrying capacity decreases, and gradually, liquid drops fall downward to the ring-shaped lifting platform 9 during the upward migration process, and the circular pipe channel 3 and the production pipe column above the circular pipe channel 3 begin to produce liquid accumulation. The liquid accumulation above the ring-shaped lifting platform 9 generates a downward pressure on the ring-shaped lifting platform 9 due to its own gravity;

[0041] Other shot gas layers below the target gas layer also have fluid production capacity, the gas produced by the other shot gas layers moves upward, enters the utility model through the oil pipe, and then enters the lower cavity 11 through the hollow mesh 6 of the circular pipe channel 3. The buoyancy of the gas produced by other gas layers below the ring-shaped lifting platform 9 into the lower cavity 11 generates an upward thrust on the ring-shaped lifting platform 9. The ring-shaped lifting platform 9 is in the initial state at this time, and the top end of the ring-shaped lifting platform 9 is kept at the same height as the top surface of the lower cavity 11, like Figure 4 ;

[0042] When the liquid accumulation of the target gas layer is serious, the downward pressure is greater than the thrust on the ring-shaped lifting platform and reaches the sliding starting pressure of the ring-shaped lifting platform, the ring-shaped lifting platform moves downward, and the top end of the ring-shaped lifting platform 9 and the top surface of the lower cavity 11 begin to have a height difference, like Figure 6; in this height difference range, the hollow mesh 6 corresponding to the lower cavity 11 on the circular tube channel 3 cannot communicate the circular tube channel 3 with the annular lifting platform 9, but communicates the circular tube channel 3 with the accumulated liquid of the target gas layer; since the gas flow rate is greater than the liquid flow rate, the gas accumulated in the lower cavity 11 corresponding to the circular tube channel 3 quickly overflows into the target gas layer wellbore environment in the production state through the hollow mesh 6, mixes with the accumulated liquid, and reduces the density of the accumulated liquid, which is equivalent to taking gas lift measures on the target production layer, and realizes spontaneous management of the accumulated liquid problem of the target production layer wellbore;

[0043] When a large amount of gas is accumulated in the lower cavity 11 so that the pushing force of the gas on the annular lifting platform 9 is greater than the gravity of the accumulated liquid above the annular lifting platform 9 and the critical contraction pressure of the spring buckle 5 on the annular weight block connecting rod 7, the annular lifting platform is pushed to move upward, as shown in Figure 5 The through hole of the annular lifting platform communicates the hollow mesh 6 of the circular tube channel 3 above and below the partition plate 8, and the gas in the lower cavity 11 enters the upper cavity 2 through the annular lifting platform 9, and then enters the production string to reach the ground; at this time, the pushing force on the annular lifting platform 9 is reduced, and the annular lifting platform 9 is pushed back to the initial position under the gravity of the annular weight block 4 and the accumulated liquid.

[0044] The annular lifting platform 9 repeatedly moves upward and falls, and the wellbore environment of the target gas layer is relatively stable, and the accumulated liquid above the annular lifting platform 9 and the gas produced by other gas layers below will not be accumulated too much to affect the normal production of the target gas layer.

[0045] Embodiment 2

[0046] On the basis of embodiment 1, further comprising that the upper cavity 2 is provided with a passage for the connecting rod 7 to pass through, and the cross section of the passage is an inverted trapezoid, the maximum width of the passage is less than the width of the annular weight block, and the minimum width is greater than the width of the spring buckle 5. The purpose of setting the passage is to support the annular weight block 4, so that the annular weight block 4 cannot fall out of the upper cavity 2, and the annular weight block 4 can only move up and down in the upper cavity 2, and to clamp the spring buckle 5.

[0047] When the force acting on the spring buckle 5 is concentrated on the lower part of the spring buckle 5, the spring buckle 5 is not easy to retract, and the connecting rod 7 needs to be subjected to a large enough upward force to push the spring buckle 5 to retract; when the force acting on the spring buckle 5 is concentrated on the upper part of the spring buckle 5, the spring buckle 5 is easy to retract, and the radial component force generated at the contact point by the self-gravity of the annular weight block 4 is enough to push the spring buckle 5 to retract. The application effect finally achieved by applying this spring buckle 5 is that the connecting rod 7 is easy to fall but not easy to lift.

[0048] Embodiment 3

[0049] On the basis of embodiment 2, further comprising, the annular lifting platform 9 comprises two annular metal plates of same size and parallel arrangement, a circular ring is arranged between the two annular metal plates, and sealing rings are arranged between the circular ring and the two annular metal plates; a guide rail 10 groove is arranged on the inner side wall of the circular ring, and a through hole is further arranged on the inner side wall of the circular ring to provide a path for fluid in the circular pipe channel 3 to enter the annular lifting platform 9. A guide rail 10 is arranged on the outer side wall of the circular pipe channel 3 below the upper cavity 2, and the guide rail 10 is matched with the guide rail 10 groove. A partition plate 8 is arranged in the circular pipe channel 3 at a position with the same height as the top end of the lower cavity 11.

[0050] Embodiment 4

[0051] On the basis of embodiment 3, further comprising, the moving distance of the annular weight block 4 in the upper cavity 2 is equal to the length of the open section. The outer side walls of the upper cavity 2 and the lower cavity 11 are in a cylindrical shape. The circular pipe channel 3 is an equal-diameter circular pipe channel 3. The cross section of the annular weight block 4 is rectangular. The upper threaded joint 1 and the lower threaded joint 12 are both circular pipes with external threads on the surface, and the upper threaded joint 1 and the upper cavity 2, and the lower threaded joint 12 and the lower cavity 11 are all welded.

[0052] In use, the utility model needs to be connected with a gas well production pipe column to become a component part thereof, the connection with the upper oil pipe column is completed through the oil pipe coupling added by the upper threaded joint 1, the connection with the lower oil pipe column is completed through the oil pipe coupling directly connected by the lower threaded joint 12, and finally the utility model is connected with the upper oil pipe column and the lower oil pipe column to become a continuous oil pipe column.

Claims

1. A wellbore device for layered production of multi-layered gas reservoirs capable of achieving equivalent gas lift function, comprising an upper cavity (2) and a lower cavity (11) sharing a central axis; the upper cavity (2) is provided with an upper threaded joint (1), and the lower cavity (11) is provided with a lower threaded joint (12); characterized in that: The center of the upper cavity (2) and the lower cavity (11) is provided with a circular pipe channel (3), the part of the circular pipe channel (3) between the upper cavity (2) and the lower cavity (11) is an open section, and the part of the circular pipe channel (3) below the upper cavity (2) is provided with a hollow mesh (6) penetrating the side wall; A ring-shaped weight block (4) is clamped in the upper cavity (2), an interface rod (7) is arranged between the upper cavity (2) and the lower cavity (11), the top end of the interface rod (7) extends into the upper cavity (2) and is connected with the ring-shaped weight block (4), the part of the top end of the interface rod (7) clamped in the upper cavity (2) is sleeved with a spring buckle (5); the bottom end of the interface rod (7) is in contact with the top end of the lower cavity (11). A ring-shaped lifting platform (9) is arranged in the lower cavity (11), the ring-shaped lifting platform (9) is in sliding connection with the part of the circular pipe channel (3) below the upper cavity (2); the inner side wall of the ring-shaped lifting platform (9) is further provided with a through hole; the part of the circular pipe channel (3) above the lower cavity (11) is not communicated with the part of the circular pipe channel (3) below the lower cavity (11).

2. The apparatus according to claim 1, wherein the apparatus is characterized in that: A channel is arranged on the upper cavity (2) for the interface rod (7) to pass through, the cross section of the channel is an inverted trapezoid, the maximum width of the channel is smaller than the width of the ring-shaped weight block, and the minimum width of the channel is greater than the width of the spring buckle (5).

3. The apparatus according to claim 2, wherein the apparatus is characterized in that: The ring-shaped lifting platform (9) comprises two ring-shaped metal plates which are parallel to each other and have the same size, a circular ring is arranged between the two ring-shaped metal plates, and sealing rings are arranged between the circular ring and the two ring-shaped metal plates; a guide rail (10) groove is arranged on the inner side wall of the circular ring, and a through hole is further arranged on the inner side wall of the circular ring.

4. The apparatus according to claim 3, wherein the apparatus is characterized in that: A guide rail (10) is arranged on the outer side wall of the circular pipe channel (3) below the upper cavity (2), and the guide rail (10) is matched with the guide rail (10) groove.

5. The apparatus of claim 4, wherein the apparatus is configured to perform the equivalent gas lift function. A partition plate (8) is arranged in the circular pipe channel (3) at the same height as the top end of the lower cavity (11).

6. The apparatus of claim 1, wherein: The moving distance of the ring-shaped weight block (4) in the upper cavity (2) is equal to the length of the open section.

7. The apparatus of claim 1, wherein: The outer side walls of the upper cavity (2) and the lower cavity (11) are in a cylindrical shape.

8. The apparatus of claim 1, wherein: The circular pipe channel (3) is a constant-diameter circular pipe channel (3).

9. The apparatus of claim 1, wherein: The cross section of the ring-shaped weight block (4) is rectangular.

10. The apparatus of claim 1, wherein the apparatus is configured to perform the equivalent gas lift function. The upper threaded joint (1) and the lower threaded joint (12) are both circular pipes with external threads on the surfaces, the upper threaded joint (1) is welded with the upper cavity (2), and the lower threaded joint (12) is welded with the lower cavity (11).

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