Uniflow acid fracturing flow control and profile control integrated device and well completion pipe string

Abstract

The invention provides a uniflow acid fracturing flow control and profile control integrated device and a well completion pipe string, and belongs to the technical field of well completion and yield increase of oil and gas wells. The well completion pipe string comprises at least one pitching type uniflow acid fracturing flow control and profile control integrated device and a differential pressure type uniflow acid fracturing flow control and profile control integrated device arranged at the lower end of the pitching type uniflow acid fracturing flow control and profile control integrated device. Flow control and profile control devices and large-displacement one-way acid fracturing valves are arranged on the cylinder walls of the outer cylinders of the ball injection type uniflow acid fracturing flow control and profile control integrated device and the differential pressure type uniflow acid fracturing flow control and profile control integrated device, so that a well completion pipe string can achieve the two functions of segmented acid fracturing and later-stage production fluid profile adjustment at the same time; profile control and water control can be achieved in the whole oil well life cycle, the low-water-content oil production period and the gas production period are prolonged, and yield increase and efficiency increase of the oil well are promoted.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas well completion and production increase, and in particular relates to a single-flow acid pressure flow control and profile adjustment integrated device and a completion string. Background Art

[0002] At present, for oil and gas reservoirs with poor reservoir properties or low-pressure and low-permeability, long horizontal wells are mostly used for staged acid fracturing or staged acidizing to increase production and completion. Generally speaking, most of the oil and gas fields developed in China have entered the middle and late stages. Blocks with good physical properties have basically been developed with wells. The remaining areas where wells can be laid generally require acid fracturing or staged acid fracturing before commercial production. For old oil fields that have entered the middle and late stages of development, as the development deepens and the formation energy is exhausted, edge and bottom water gradually invade, and some newly drilled wells face the problem of rapid high water content after production. Therefore, adjusting the production profile, controlling the water production rate, and extending the low-water-content oil production period and the low-water-content gas production period have become urgent needs for the efficient development of oil and gas reservoirs in the middle and late stages of development. At present, staged acid fracturing is mainly achieved by multi-stage acid fracturing sliding sleeves + staged packers; and adjusting the production profile usually requires segmentation and the insertion of a separate production profile adjustment tool, or the insertion of a separate injection tool to inject a profile adjustment plugging agent to achieve it. Currently, conventional acid fracturing wells do not have the function of adjusting the production profile. In addition, for horizontal wells with multi-stage acid fracturing sleeves, since only the opening of the sleeve is the channel connecting the wellbore to the reservoir, there are few points for chemical injection into the reservoir, and the desire to accurately adjust the profile, plug the water and control the production of formation water is limited.

[0003] In view of the fact that the edge wells or infill wells of oil and gas reservoirs in the middle and late stages of development currently need acid fracturing to increase oil and gas production, and the oil and gas reservoir wells in the middle and late stages of development face the risk of rapid high water content or violent flooding after acid fracturing, in view of the need for acid fracturing and control of the production profile of new oil and gas wells in the middle and late stages of development, and considering the limitations of the acid fracturing string that the production profile cannot be adjusted mechanically to control water, and the acid fracturing string uses chemical agents to implement profile adjustment and water plugging, it is an urgent problem to design a tool system based on a completion operation string that can simultaneously achieve segmented acid fracturing and later adjustment of the production profile. Summary of the invention

[0004] The purpose of the present invention is to solve the problems existing in the above-mentioned prior art and to provide a single-flow acid fracturing flow control and profile adjustment integrated device and completion string, which can realize the functions of segmented acid fracturing and adjusting the production liquid profile to control water through one process string operation.

[0005] One of the purposes of the present invention is to provide a ball-throwing single-flow acid pressure flow control and profile adjustment integrated device.

[0006] The second purpose of the present invention is to provide a differential pressure single-flow acid pressure flow control and profile adjustment integrated device.

[0007] A third object of the present invention is to provide a completion string.

[0008] The present invention is achieved through the following technical solutions:

[0009] The first aspect of the present invention provides a ball-throwing single-flow acid pressure flow control and profile control integrated device, comprising an outer cylinder, wherein an upper connecting joint, an outer sliding sleeve and a lower connecting joint are sequentially arranged from top to bottom in the outer cylinder, an inner sliding sleeve is arranged in the outer sliding sleeve, and a ball seat is arranged at the bottom of the inner sliding sleeve;

[0010] The outer cylinder wall is provided with a flow control and profile adjustment device and a large-displacement one-way acid pressure valve.

[0011] A further improvement of the present invention is:

[0012] The flow control and profile adjustment device includes a device body, and the device body is provided with an inlet, an inlet channel and a flow control and profile adjustment oil and gas mixture diversion channel connected in sequence from one end face to the other end face. The inlet is arranged on one side of the inner wall of the outer tube, and the flow control and profile adjustment oil and gas mixture diversion channel is arranged on one side outside the outer tube.

[0013] A further improvement of the present invention is:

[0014] The large-displacement one-way acid pressure valve comprises a valve body, on which an acid pressure injection port and an acid pressure outflow port which are interconnected are arranged, an acid pressure closing plate is arranged on the end surface of the valve body located at one end of the acid pressure outflow port, a spring is connected to the inner side of the acid pressure closing plate, and the other end of the spring is fixed to the inner wall of the acid pressure outflow port;

[0015] The acid pressure injection port is arranged at one side of the inner wall of the outer tube, and the acid pressure outflow port is arranged at one side of the outer wall of the outer tube.

[0016] A further improvement of the present invention is:

[0017] An upper joint is provided at the upper part of the outer tube, the upper joint is connected to the upper connecting joint through an upper joint male buckle joint, and an upper joint sealing ring is provided between the upper joint and the inner wall of the outer tube;

[0018] A lower joint is provided at the lower part of the outer tube, the lower joint is connected to the lower connecting joint through a lower joint male buckle joint, and a lower joint sealing ring is provided between the lower joint and the inner wall of the outer tube.

[0019] A further improvement of the present invention is:

[0020] There is a certain gap between the upper connecting joint, the outer sleeve, the lower connecting joint and the outer cylinder to form an internal flow cavity;

[0021] The outer sleeve is provided with an acid injection hole, the inner sleeve is arranged inside the outer sleeve and fixedly connected by a pin, and the inner sleeve blocks the acid injection hole.

[0022] A second aspect of the present invention provides a differential pressure single-flow acid pressure flow control and profile control integrated device, comprising an outer cylinder, wherein an upper connector, an outer sleeve and a lower connector are sequentially arranged from the upper right to the bottom in the outer cylinder, an inner sleeve is arranged in the outer sleeve, and an inner sleeve is provided with a large inner sleeve cross section at the upper part of the inner sleeve and a small inner sleeve cross section at the lower part;

[0023] The outer cylinder wall is provided with a flow control and profile adjustment device and a large-displacement one-way acid pressure valve.

[0024] A further improvement of the present invention is:

[0025] The flow control and profile adjustment device includes a device body, and the device body is provided with an inlet, an inlet channel and a flow control and profile adjustment oil and gas mixture diversion channel connected in sequence from one end face to the other end face. The inlet is arranged on one side of the inner wall of the outer tube, and the flow control and profile adjustment oil and gas mixture diversion channel is arranged on one side outside the outer tube.

[0026] A further improvement of the present invention is:

[0027] The large-displacement one-way acid pressure valve comprises a valve body, on which an acid pressure injection port and an acid pressure outflow port which are interconnected are arranged, an acid pressure closing plate is arranged on the end surface of the valve body located at one end of the acid pressure outflow port, a spring is connected to the inner side of the acid pressure closing plate, and the other end of the spring is fixed to the inner wall of the acid pressure outflow port;

[0028] The acid pressure injection port is arranged at one side of the inner wall of the outer tube, and the acid pressure outflow port is arranged at one side of the outer wall of the outer tube.

[0029] A further improvement of the present invention is:

[0030] An upper joint is provided at the upper part of the outer tube, the upper joint is connected to the upper connecting joint through an upper joint male buckle joint, and an upper joint sealing ring is provided between the upper joint and the inner wall of the outer tube;

[0031] A lower joint is provided at the lower part of the outer tube, the lower joint is connected to the lower connecting joint through a lower joint male buckle joint, and a lower joint sealing ring is provided between the lower joint and the inner wall of the outer tube.

[0032] A further improvement of the present invention is:

[0033] There is a certain gap between the upper connecting joint, the outer sleeve, the lower connecting joint and the outer cylinder to form an internal flow cavity;

[0034] The outer sleeve is provided with an acid injection hole, the inner sleeve is arranged inside the outer sleeve and fixedly connected by a pin, and the inner sleeve blocks the acid injection hole.

[0035] The third aspect of the present invention provides a completion tubing string, comprising at least one ball-dropping single-flow acid pressure flow control and profile control integrated device and a differential pressure single-flow acid pressure flow control and profile control integrated device arranged at the lower end of the ball-dropping single-flow acid pressure flow control and profile control integrated device.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] The completion string of the present invention can meet the requirements of edge wells or infill wells of oil and gas reservoirs with poor reservoir properties or in the middle and late stages of development. On the one hand, segmented acid fracturing is required to achieve commercial production. On the other hand, due to the rising water line and the complex oil-water relationship, it is necessary to consider the need to adjust the production profile caused by rapid high water content or violent flooding after acid fracturing.

[0038] Considering that conventional chemical injection for profile control and water plugging cannot be accurately sealed and injected due to the limitation of the inner diameter of the segmented acid fracturing sleeve, and the effective period is relatively short; and the conventional segmented acid fracturing tubing cannot be lowered into a segmented water control tubing system to adjust the production profile. At the same time, the mechanical water control tool tubing generally achieves water control through special flow channels or special mechanical structures. Because it has a structure that identifies different fluids to produce throttling effects, the flow channels are relatively small, which is contrary to the principle that acid fracturing requires a large amount of injection into the formation in a short period of time to form an effective positive pressure to fracture the rock. The completion tubing of the present invention can simultaneously realize the two functions of segmented acid fracturing and subsequent adjustment of the production profile, which can increase the oil and gas production of a single well, control the profile and control water throughout the life cycle of the oil well, extend the low water content oil production period and gas production period, and help increase the production and efficiency of oil wells. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a structural diagram of a ball-throwing single-flow acid fracturing flow control and profile adjustment integrated device;

[0040] Figure 2 This is a structural diagram of a differential pressure single-flow acid pressure flow control and profile control integrated device;

[0041] Figure 3 This is the structural diagram of the flow control and profile adjustment device;

[0042] Figure 4 This is the structural diagram of a large-displacement one-way acid pressure valve.

[0043] In the figure, 1, outer cylinder, 2, upper connecting joint, 3, outer sliding sleeve, 4, lower connecting joint, 5, inner sliding sleeve, 6, ball seat, 7, flow control and profile control device, 7-1, flow control and profile control oil-gas-water mixture diversion flow channel, 7-2, inlet flow channel, 7-3, inlet, 8, large-displacement one-way acid pressure valve, 8-1, acid pressure injection port, 8-2, acid pressure closing plate, 8-3, acid pressure flow outlet, 8-4, spring, 9, upper joint, 10, upper joint male joint, 11, upper joint sealing ring, 12, lower joint, 13, lower joint male joint, 14, internal flow cavity, 15, acid pressure injection hole, 16, pin, 17, inner sleeve with large cross section, 18, inner sleeve with small cross section. DETAILED DESCRIPTION

[0044] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0045] At present, wells at the edge of oil and gas reservoirs with poor reservoir properties or in the middle and late stages of development or infill wells need staged acid fracturing to achieve commercial production. For oil and gas reservoirs or edge wells in the middle and late stages of development, due to the rising waterline and complex oil-water relationship, they often face the risk of rapid high water content or violent flooding, resulting in acid fracturing and adjusting the production profile to control water. Conventional chemical injection profile control and water plugging cannot be accurately sealed and injected due to the limitation of the inner diameter of the staged acid fracturing sleeve, and the effective period is relatively short; and the conventional staged acid fracturing string cannot be put into the staged water control to adjust the production profile. The tubing system, and the mechanical water control tool tubing generally achieves water control through special flow channels or special mechanical structures. Because it has special flow channels or special structures that identify different fluids to produce throttling effects, the flow channels are generally relatively small, which is contrary to the principle that acid fracturing requires a large amount of injection into the formation in a short period of time to form an effective positive pressure to fracture the rock. Therefore, it is necessary to design a tool system based on a completion operation tubing that can simultaneously achieve segmented acid fracturing and later adjustment of the production profile. The functions of segmented acid fracturing and adjustment of the production profile to control water can be achieved through a single process tubing operation.

[0046] [Example 1]

[0047] like Figure 1 As shown, this embodiment provides a ball-throwing single-flow acid fracturing integrated flow control and profile adjustment device, comprising an outer tube 1, in which an upper connecting joint 2, an outer sleeve 3 and a lower connecting joint 4 connected in sequence are arranged from top to bottom, an inner sleeve 5 is arranged in the outer sleeve 3, and a ball seat 6 is arranged at the bottom of the inner sleeve 5; a flow control and profile adjustment device 7 and a large-displacement one-way acid fracturing valve 8 are arranged on the wall of the outer tube 1.

[0048] The number of flow control and profile control devices 7 and large-displacement one-way acid pressure control valves 8 is set according to needs. The flow control and profile control devices 7 and large-displacement one-way acid pressure control valves 8 are respectively arranged on the outer tube 1 at intervals and evenly distributed in a ring. Among them, the flow control and profile control devices 7 are arranged in 1 to 2 circles, 2 are arranged in each circle, and a total of 2 to 4 are arranged. The large-displacement one-way acid pressure control valves 8 are arranged in 3 to 4 circles, 3 are arranged in each circle, and a total of 9 to 12 are arranged.

[0049] The main function of the outer tube 1 is to construct a sealed space. The flow control and profile control device 7 and the large-displacement one-way acid pressure valve 8 are installed on the wall of the outer tube 1, so that the fluid outside or inside the outer tube can only flow through the flow control and profile control device 7 and the large-displacement one-way acid pressure valve 8.

[0050] Furthermore, an upper joint 9 is provided at the upper part of the outer tube 1, which is normally connected to the oil pipe or other upper completion string tools. The upper joint 9 is connected to the upper connecting joint 2 through an upper joint male buckle joint 10, and an upper joint sealing ring 11 is provided between the upper joint 9 and the inner wall of the outer tube 1 to prevent external fluid from entering the interior of the device through the gap between the upper joint 9 and the outer tube 1; a lower joint 12 is provided at the lower part of the outer tube 1, which is normally connected to the oil pipe or other lower completion string tools. The lower joint 12 is connected to the lower connecting joint 4 through a lower joint male buckle joint 13, and a lower joint sealing ring is provided between the lower joint 12 and the inner wall of the outer tube 1 to prevent external fluid from entering the interior of the device through the gap between the lower upper joint 12 and the outer tube 1.

[0051] Furthermore, there is a certain gap between the upper connection joint 2, the outer sleeve 3, the lower connection joint 4 and the outer tube 1 to form an internal flow chamber 14. The upper part of the outer sleeve 3 is connected to the upper connection joint 2, blocking the inner sleeve 5, facilitating the installation and sealing of the inner sleeve 5 and the outer sleeve 3; the lower part of the outer sleeve 3 is connected to the lower connection joint 4, cooperates with the upper connection joint 2, and is installed in the upper joint 9, the lower joint 12 and the outer tube, thereby forming a sliding opening structure, forming a seal and a travel space for the inner sleeve.

[0052] Furthermore, an acid injection hole 15 is provided on the outer sleeve 3 , and the inner sleeve 5 is disposed inside the outer sleeve 3 and fixedly connected via a pin 16 , so that the inner sleeve 5 blocks the acid injection hole 15 .

[0053] A ball seat 6 is installed at the bottom of the inner sleeve 5. When a ball is dropped from the wellhead onto the ball seat 6 and pressure is applied, the ball blocks the ball seat 6 to form a pressure build-up. The pressure pushes the ball seat 6 to drive the inner sleeve 5 to move downward. When the pressure is greater than the shear value of the pin 16, the pin 16 is sheared off, the inner sleeve 5 moves downward, and the acid pressure injection hole 15 sealed by the inner sleeve 5 leaks out. At this time, the acid pressure injected into the completion string can enter the internal flow cavity 14 through the acid pressure injection hole 15, and then enter the wellbore and the reservoir through the flow control and profile adjustment device 7 and the large-displacement one-way acid pressure valve 8, thereby completing the acid pressure. After the inner sleeve 5 slides open, it will remain in the open state.

[0054] [Example 2]

[0055] like Figure 2 As shown, this embodiment provides a pressure differential single-flow acid pressure flow control and profile control integrated device, including an outer tube 1, in which an upper connector 2, an outer sleeve 3 and a lower connector 4 are arranged from the upper right to the bottom, an inner sleeve 5 is arranged in the outer sleeve 3, and the upper part of the inner sleeve 5 is provided with an inner sleeve large cross-section 17, and the lower part is provided with an inner sleeve small cross-section 18; a flow control and profile control device 7 and a large-displacement one-way acid pressure valve 8 are arranged on the wall of the outer tube 1.

[0056] The number of flow control and profile control devices 7 and large-displacement one-way acid pressure control valves 8 is set according to needs. The flow control and profile control devices 7 and large-displacement one-way acid pressure control valves 8 are respectively arranged on the outer tube 1 at intervals and evenly distributed in a ring. Among them, the flow control and profile control devices 7 are arranged in 1 to 2 circles, 2 are arranged in each circle, and a total of 2 to 4 are arranged. The large-displacement one-way acid pressure control valves 8 are arranged in 3 to 4 circles, 3 are arranged in each circle, and a total of 9 to 12 are arranged.

[0057] The main function of the outer tube 1 is to construct a sealed space. The flow control and profile control device 7 and the large-displacement one-way acid pressure valve 8 are installed on the wall of the outer tube 1, so that the fluid outside or inside the outer tube can only flow through the flow control and profile control device 7 and the large-displacement one-way acid pressure valve 8.

[0058] Furthermore, an upper joint 9 is provided at the upper part of the outer tube 1, which is normally connected to the oil pipe or other upper completion string tools. The upper joint 9 is connected to the upper connecting joint 2 through an upper joint male buckle joint 10, and an upper joint sealing ring 11 is provided between the upper joint 9 and the inner wall of the outer tube 1 to prevent external fluid from entering the interior of the device through the gap between the upper joint 9 and the outer tube 1; a lower joint 12 is provided at the lower part of the outer tube 1, which is normally connected to the oil pipe or other lower completion string tools. The lower joint 12 is connected to the lower connecting joint 4 through a lower joint male buckle joint 13, and a lower joint sealing ring is provided between the lower joint 12 and the inner wall of the outer tube 1 to prevent external fluid from entering the interior of the device through the gap between the lower upper joint 12 and the outer tube 1.

[0059] Furthermore, there is a certain gap between the upper connection joint 2, the outer sleeve 3, the lower connection joint 4 and the outer tube 1 to form an internal flow chamber 14. The upper part of the outer sleeve 3 is connected to the upper connection joint 2, blocking the inner sleeve 5, facilitating the installation and sealing of the inner sleeve 5 and the outer sleeve 3; the lower part of the outer sleeve 3 is connected to the lower connection joint 4, cooperates with the upper connection joint 2, and is installed in the upper joint 9, the lower joint 12 and the outer tube, thereby forming a sliding opening structure, forming a seal and a travel space for the inner sleeve.

[0060] Furthermore, an acid injection hole 15 is provided on the outer sleeve 3 , and the inner sleeve 5 is disposed inside the outer sleeve 3 and fixedly connected via a pin 16 , so that the inner sleeve 5 blocks the acid injection hole 15 .

[0061] The inner sleeve 5 is provided with an inner sleeve large cross section 17 at the upper part and an inner sleeve small cross section 18 at the lower part, that is to say, the cross section of the upper end face of the inner sleeve 5 is larger than the cross section of the lower end face, and the orthographic projection area of ​​the cross section perpendicular to the flow direction of the fluid in the device and the size of the projection area of ​​this cross section determine the size of the force, and the difference in the orthographic projection area of ​​the cross section determines the difference in force.

[0062] After the wellhead is pressurized, different pressure values ​​are generated between the inner sleeve large section 17 and the inner sleeve small section 18 due to the cross-sectional area difference, thereby pushing the inner sleeve 5 to slide from the inner sleeve large section 17 to the inner sleeve small section 18. When the pressure difference generated by the cross-sectional area difference is greater than the shear value of the pin 16, the pin 16 is sheared off, the inner sleeve 5 retreats and opens, and the acid injection hole 15 sealed by the inner sleeve 5 leaks out. At this time, the acid injected into the completion string can enter the internal flow cavity 14 through the acid injection hole 15, and then enter the wellbore and the reservoir through the flow control and profile adjustment device 7 and the large-displacement one-way acid pressure valve 8, thereby completing the acid pressure. After the inner sleeve slides open, it will remain in the open state.

[0063] [Example 3]

[0064] like Figure 3 As shown, the flow control and profile adjustment device 7 includes a device body, and the device body is provided with an inlet 7-3, an inlet channel 7-2 and a flow control and profile adjustment oil-gas mixture diversion flow channel 7-1 which are connected in sequence from one end face to the other end face, wherein the inlet 7-3 is arranged on one side of the inner wall of the outer tube, and the flow control and profile adjustment oil-gas mixture diversion flow channel 7-1 is arranged on one side of the outer tube.

[0065] The flow control and profile adjustment oil-gas mixture diversion flow channel 7-1 is a multi-section internal spiral flow channel with a symmetrical structure. The flow direction of the incoming mixed fluid is changed through the multi-section internal spiral flow channel. Under the joint operation of gravity, viscosity and centrifugal force, the oil phase, water phase or gas phase with different viscosities and gravities in the mixed liquid with different water saturations will enter different flow channels, and then the flow channel lengths of different phases and the time of entering the inlet channel 7-2 are different, thereby realizing the function of adding different inlet resistances to different phases of oil, gas and water, and achieving the purpose of controlling the inlet profile.

[0066] During large-scale acid fracturing, the acid in the completion string passes through the inlet 7-3, then enters the inlet channel 7-2, and enters the formation through the flow control and profile control oil and gas mixture diversion channel 7-1. The acid in the acid fracturing process can enter the formation in small amounts through the flow control and profile control device.

[0067] During production, after the fluid in the reservoir enters the wellbore, different viscosities and additional resistances are added to different phase substances in the fluid mixture with different water saturations through the flow control and profile control oil-gas mixture diversion flow channel 7-1, and then the fluid enters the outer tube 1 through the inlet channel 7-2 and the inlet 7-3, and is thus produced. The well is segmented by inserting a packer when the completion string is lowered. The flow control and profile control devices in different segments will generate different viscosities and additional resistances for fluids with different water saturations, thereby playing a flow control and profile control role on the entire wellbore inlet profile.

[0068] [Example 4]

[0069] like Figure 4 As shown, the large-displacement one-way acid pressure valve 8 includes a valve body, on which are provided an acid pressure injection port 8-1 and an acid pressure outlet port 8-3 which are interconnected, and on the end face of the valve body at one end of the acid pressure outlet port 8-3, an acid pressure closing plate 8-2 is provided, and the inner side of the acid pressure closing plate 8-2 is connected to a spring 8-4, and the other end of the spring 8-4 is fixed to the inner wall of the acid pressure outlet port 8-3.

[0070] The acid pressure injection port 8 - 1 is disposed on one side of the inner wall of the outer tube 1 , and the acid pressure outlet port 8 - 3 is disposed on one side of the outer wall of the outer tube 1 .

[0071] Since the outflow volume during acid fracturing is relatively large, in order to meet the demand for acid fracturing volume, it is necessary to consider the inlet and outlet apertures that meet the acid fracturing volume and the number of large-displacement one-way acid fracturing valves to be installed. The flow control and profile control device needs to control the flow, so the inlet and outlet apertures are relatively small. In order to meet the acid fracturing and flow control and profile control functions in one trip, it is necessary to inject acid into the reservoir in a large volume. During production, the flow control and profile control device can only be the only inlet and outlet. Therefore, a large-displacement one-way acid fracturing valve is required. During the acid fracturing process, the completion string The acid enters the valve body through the acid fracturing injection port 8-1, squeezes open the acid fracturing closing plate 8-2, and then enters the wellbore and the reservoir through the acid fracturing outlet 8-3. When the acid fracturing is completed, during normal production, due to the production pressure difference inside and outside the completion string and the rebound effect of the spring 8-4, the large-displacement one-way acid fracturing valve is closed. During the entire production process, the large-displacement one-way acid fracturing valve is in a closed state, and the oil, gas and water produced in the reservoir can only enter the completion string through the flow and profile control device, thereby realizing the flow control and profile control function.

[0072] [Example 5]

[0073] This embodiment provides a completion string, including at least one ball-dropping single-flow acid pressure flow control and profile control integrated device and a differential pressure single-flow acid pressure flow control and profile control integrated device arranged at the lower end of the ball-dropping single-flow acid pressure flow control and profile control integrated device.

[0074] Among them, the topmost ball-throwing single-flow acid pressure flow control and profile control integrated device is connected to the upper completion string at the upper end, and the lower end of the pressure differential single-flow acid pressure flow control and profile control integrated device is connected to the downhole safety isolation valve (ball valve); and a packer is arranged between two adjacent ball-throwing single-flow acid pressure flow control and profile control integrated devices, and a packer is arranged between the ball-throwing single-flow acid pressure flow control and profile control integrated device and the pressure differential single-flow acid pressure flow control and profile control integrated device.

[0075] When installing and lowering, first connect the downhole safety isolation valve (ball valve), then connect the differential pressure single-flow acid pressure flow control and profile control integrated device ( Figure 2 )+packer, and then connect multiple ball-throwing single-flow acid fracturing flow control and profile control integrated devices according to the needs of staged fracturing ( Figure 1 )+packer combination, and then connect the upper completion string, etc. During acid fracturing, first throw the corresponding soluble ball of the downhole safety isolation valve, hold the pressure to seal the segmented packer and the hanging packer, and then pump in acid fracturing. Hold the pressure to a relatively larger level to open the differential single-flow acid fracturing flow control and profile adjustment integrated device for acid fracturing. After this section of acid fracturing is completed, throw different segments into Figure 1 Soluble balls of corresponding sizes are used to open the ball-throwing single-flow acid fracturing flow control and profile control integrated device for acid fracturing. After the acid fracturing of different sections is completed, the ball is released to lift out the upper completion string and then put into the oil pipe for production. During production, the fluid in the reservoir can only enter the bottom completion string through the flow control and profile control device and then be produced. The flow control and profile control device acts on different phases of the gas-liquid, oil-water or oil-gas-water three-phase fluid produced by the reservoir with different throttling pressure differences, thereby achieving almost no throttling pressure difference for gas, low throttling pressure difference for oil, and high throttling pressure difference for water, thereby achieving water control for the fluids produced in different sections and realizing the function of adjusting the liquid production profile of the entire well section.

[0076] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0077] In the description of the present invention, unless otherwise specified, the terms "upper", "lower", "left", "right", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0078] The above technical solution is only one implementation mode of the present invention. For those skilled in the art, it is easy to make various types of improvements or modifications based on the principles disclosed in the present invention, and it is not limited to the technical solution described in the above specific embodiments of the present invention. Therefore, the above description is only preferred and does not have a restrictive meaning.

Claims

1. A ball-throwing single-flow acid fracturing flow control and profile control integrated device, characterized in that: It comprises an outer cylinder, wherein an upper connecting joint, an outer sliding sleeve and a lower connecting joint are sequentially arranged from top to bottom in the outer cylinder, an inner sliding sleeve is arranged in the outer sliding sleeve, and a ball seat is arranged at the bottom of the inner sliding sleeve; The outer cylinder wall is provided with a flow control and profile adjustment device and a large-displacement one-way acid pressure valve.

2. The ball-throwing single-flow acid pressure flow control and profile adjustment integrated device according to claim 1 is characterized in that: The flow control and profile adjustment device includes a device body, and the device body is provided with an inlet, an inlet channel and a flow control and profile adjustment oil and gas mixture diversion channel connected in sequence from one end face to the other end face. The inlet is arranged on one side of the inner wall of the outer tube, and the flow control and profile adjustment oil and gas mixture diversion channel is arranged on one side outside the outer tube.

3. The ball-throwing single-flow acid pressure flow control and profile adjustment integrated device according to claim 1 is characterized in that: The large-displacement one-way acid pressure valve comprises a valve body, on which an acid pressure injection port and an acid pressure outflow port which are interconnected are arranged, an acid pressure closing plate is arranged on the end surface of the valve body located at one end of the acid pressure outflow port, a spring is connected to the inner side of the acid pressure closing plate, and the other end of the spring is fixed to the inner wall of the acid pressure outflow port; The acid pressure injection port is arranged at one side of the inner wall of the outer tube, and the acid pressure outflow port is arranged at one side of the outer wall of the outer tube.

4. The ball-throwing single-flow acid pressure flow control and profile adjustment integrated device according to claim 1 is characterized in that: An upper joint is provided at the upper part of the outer tube, the upper joint is connected to the upper connecting joint through an upper joint male buckle joint, and an upper joint sealing ring is provided between the upper joint and the inner wall of the outer tube; A lower joint is provided at the lower part of the outer tube, the lower joint is connected to the lower connecting joint through a lower joint male buckle joint, and a lower joint sealing ring is provided between the lower joint and the inner wall of the outer tube.

5. The ball-throwing single-flow acid pressure flow control and profile adjustment integrated device according to claim 1 is characterized in that: There is a certain gap between the upper connecting joint, the outer sleeve, the lower connecting joint and the outer cylinder to form an internal flow cavity; The outer sleeve is provided with an acid injection hole, the inner sleeve is arranged inside the outer sleeve and fixedly connected by a pin, and the inner sleeve blocks the acid injection hole.

6. A differential pressure single-flow acid pressure flow control and profile control integrated device, characterized in that: It comprises an outer cylinder, wherein an upper connector, an outer sleeve and a lower connector are sequentially arranged from the upper right to the lower right of the outer cylinder, an inner sleeve is arranged inside the outer sleeve, and an inner sleeve has a large inner sleeve section at the upper part and a small inner sleeve section at the lower part; The outer cylinder wall is provided with a flow control and profile adjustment device and a large-displacement one-way acid pressure valve.

7. The differential pressure single-flow acid pressure flow control and profile control integrated device according to claim 6, characterized in that: The flow control and profile adjustment device includes a device body, and the device body is provided with an inlet, an inlet channel and a flow control and profile adjustment oil and gas mixture diversion channel connected in sequence from one end face to the other end face. The inlet is arranged on one side of the inner wall of the outer tube, and the flow control and profile adjustment oil and gas mixture diversion channel is arranged on one side outside the outer tube.

8. The differential pressure single-flow acid pressure flow control and profile control integrated device according to claim 6, characterized in that: The large-displacement one-way acid pressure valve comprises a valve body, on which an acid pressure injection port and an acid pressure outflow port which are interconnected are arranged, an acid pressure closing plate is arranged on the end surface of the valve body located at one end of the acid pressure outflow port, a spring is connected to the inner side of the acid pressure closing plate, and the other end of the spring is fixed to the inner wall of the acid pressure outflow port; The acid pressure injection port is arranged at one side of the inner wall of the outer tube, and the acid pressure outflow port is arranged at one side of the outer wall of the outer tube.

9. The differential pressure single-flow acid pressure flow control and profile control integrated device according to claim 6, characterized in that: An upper joint is provided at the upper part of the outer tube, the upper joint is connected to the upper connecting joint through an upper joint male buckle joint, and an upper joint sealing ring is provided between the upper joint and the inner wall of the outer tube; A lower joint is provided at the lower part of the outer tube, the lower joint is connected to the lower connecting joint through a lower joint male buckle joint, and a lower joint sealing ring is provided between the lower joint and the inner wall of the outer tube.

10. The differential pressure single-flow acid pressure flow control and profile control integrated device according to claim 6, characterized in that: There is a certain gap between the upper connecting joint, the outer sleeve, the lower connecting joint and the outer cylinder to form an internal flow cavity; The outer sleeve is provided with an acid injection hole, the inner sleeve is arranged inside the outer sleeve and fixedly connected by a pin, and the inner sleeve blocks the acid injection hole.

11. A completion string, characterized in that: It comprises at least one ball-throwing single-flow acid pressure flow control and profile adjustment integrated device as described in any one of claims 1 to 5 and a differential pressure single-flow acid pressure flow control and profile adjustment integrated device as described in any one of claims 6 to 10 arranged at the lower end of the ball-throwing single-flow acid pressure flow control and profile adjustment integrated device.

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