Sand prevention and water control integrated well completion pipe string and well completion process method

Abstract

The invention discloses a sand prevention and water control integrated well completion pipe string and a well completion process method. The technical problem that an existing well completion pipe string cannot achieve sand prevention and water control at the same time is solved. The sand prevention and water control integrated well completion pipe string comprises a shaft isolation hanger, a filling sliding sleeve, a sand prevention and water control assembly and a float shoe which are connected in sequence, a plurality of open hole segmented packers are arranged on the sand prevention and water control assembly, and the sand prevention and water control assembly comprises a plurality of screen pipe assemblies which are connected with one another; each screen pipe assembly comprises a screen pipe base pipe, a screen pipe coupling, a flow control coupling, a connector, a screen sleeve assembly, an outer sleeve, a self-adaptive flow control device and the like. Self-adaptive sand control and water control can be achieved, sand control is guaranteed, meanwhile, the requirement for water control in the production stage is met, and sand control and water control integrated treatment is achieved in the well completion stage.

Description

Technical Field

[0001] This invention belongs to the field of well completion engineering technology, specifically relating to an integrated sand control and water control well completion string and well completion process. Background Technology

[0002] The development of marine oil and gas resources is a current hot topic and focus of the world's marine economy. Marine oil and gas resources are not only abundant, but modern science and technology have also given us the ability to develop them. The marine oil and gas industry has developed into a new and high-value leading industry in the marine economy.

[0003] Currently, offshore oilfield reservoirs are characterized by high porosity, high permeability, and weak cementation strength. Meanwhile, water-driven reservoirs account for over 95% of proven reserves in producing oilfields, with sand production and high water cut being particularly prominent issues. Current water control technologies mainly focus on post-high water cut conditions, well workover stages, and passive water shut-off. This results in low success rates, short effective periods, and insufficient exploitation of remaining oil. Less than 5% of wells implement water control measures during the well completion stage, severely limiting single-well productivity.

[0004] Therefore, given the unique characteristics of offshore oilfield development, there is an urgent need to design an integrated sand control and water control well completion string and completion process to achieve integrated sand control and water control in oil wells. Summary of the Invention

[0005] In order to solve all or part of the above problems, the purpose of this invention is to provide an integrated sand control and water control well completion string and well completion process method, which can achieve adaptive sand control and water control, ensuring sand control while taking into account the water control needs of the production stage, and realizing integrated sand control and water control in the well completion stage.

[0006] In a first aspect, the present invention provides an integrated sand control and water control completion string, comprising a wellbore isolation hanger, a filling sleeve, a sand control and water control assembly, and a float shoe connected in sequence. The sand control and water control assembly is connected in sequence with a plurality of open-hole segment packers to achieve formation separation.

[0007] The sand control and water control assembly includes multiple screen pipe assemblies connected in sequence, each of the screen pipe assemblies comprising:

[0008] Screen tube base tube;

[0009] A screen pipe coupling is connected to the end of the screen pipe base pipe;

[0010] A flow control coupling is connected to the end of the screen tube base pipe away from the screen tube coupling.

[0011] A connector is located at the end of the flow control coupling away from the screen tube base tube, and the connector mates with the screen tube coupling;

[0012] A screen sleeve assembly is connected to the screen tube base tube, and a first filter ring cavity is formed between the screen sleeve assembly and the screen tube base tube;

[0013] The outer sleeve is connected at one end to the screen sleeve assembly and at the other end to the flow control coupling, and a second filter ring cavity is formed between the outer sleeve and the flow control coupling;

[0014] A connecting hole is provided on the screen sleeve assembly and connects the first filter ring cavity and the second filter ring cavity;

[0015] The mounting hole is provided on the flow control coupling and connects the second filter ring cavity with the inside of the screen tube base tube;

[0016] An adaptive flow control device is disposed within the mounting hole.

[0017] Optionally, multiple mounting holes are provided, and the multiple mounting holes are arranged at equal intervals along the circumference of the flow control coupling, and each mounting hole is provided with the adaptive flow control device.

[0018] Optionally, the outer sleeve, the screen sleeve assembly, and the flow control coupling are sealed by sealing rings.

[0019] Optionally, the screen sleeve assembly includes:

[0020] The outer end ring is fixed to the screen tube base tube;

[0021] The inner end ring is fixed to the screen tube base tube;

[0022] A filter sleeve is fitted onto the screen tube base tube, with one end of the filter sleeve connected to the outer end ring and the other end connected to the inner end ring;

[0023] The outer sleeve is connected to the inner end ring, and the connecting hole is disposed through the inner end ring.

[0024] Optionally, the naked-eye segmented packer is an oil- or water-swellable packer, an extrusion-expandable packer, or a compression-expandable packer.

[0025] Secondly, the present invention provides a well completion process method, which uses a well completion string and includes the following steps:

[0026] S1, based on the geological structure of the target well, well logging interpretation data, drilling conditions, formation fluid characteristics, production well history, and adjacent well data, analyzes and understands the oil well's production capacity, produced fluid ratio, and oil-water distribution.

[0027] S2, based on the reservoir properties of the target well, open-hole segmented packers are deployed at the property difference boundary, mudstone interlayer, and water-flooded section to isolate the formation, resolve interlayer conflicts, and prevent large-scale water channeling.

[0028] S3. Based on the analysis of formation sand particle size, select the sand-blocking accuracy and the size and type of filling medium of the sand-control and water-control assembly according to the sand control parameters of adjacent wells in the same sand body and the same layer.

[0029] S4. Based on the target well's production capacity, crude oil viscosity, permeability distribution, oil / water saturation, and formation pressure parameters, select the arrangement method, number, and specifications of tubing strings for each production zone.

[0030] S5. Based on the data results from S1-S4, assemble the various components of the completion string.

[0031] S6, Run in the completion string, and set the wellbore isolation hanger and multiple open hole segment packers according to the construction design, and perform the hanger test, sealing test and release operation;

[0032] S7. Connect and pressure test the external filling equipment according to the construction design, and conduct squeezing test, forward circulation test and reverse circulation test.

[0033] S8. Based on the test results in S7, check the formation pressure failure, open the filling sleeve, and fill with gravel through external filling equipment until the set sand removal pressure is reached, and then end the filling operation.

[0034] S9 adopts a method of slow frequency increase, frequent tracking, and frequent observation in the early stage of oil well production.

[0035] Optionally, in S3, the filling medium uses an organic polymer as aggregate, coated with multiple layers of resin film, with the outermost resin film having a contact angle with water >160° and an apparent density <1.05 g / cm³. 3 .

[0036] Optionally, S8 includes the following steps:

[0037] S81, calculate the wellbore flow friction based on reverse circulation test, and calculate the formation fracture pressure through injection test. Determine 85% of the formation fracture pressure as the safe pressure limit based on the wellbore flow friction and the formation fracture pressure.

[0038] S82, calculate formation leakage based on positive circulation test, and back-calculate construction discharge volume by combining formation leakage and wellbore safety discharge volume;

[0039] S83, Select the filling pumping procedure for external filling equipment based on safety pressure limit and construction discharge capacity;

[0040] S84, filling operations are carried out using external filling equipment.

[0041] Optionally, in S84, a stepped reduction in discharge rate is adopted for the filling operation, which limits pressure but not discharge rate, to fill the gap between the reservoir and the completion string and the reservoir void zone densely.

[0042] Optionally, S84 includes the following steps:

[0043] S841, start pumping at a filling displacement of 8-12 bpm and monitor the filling pressure in real time;

[0044] S842, if the formation pressure is less than 85% of the pressure breaking point, continue pumping; if the formation pressure is greater than 85% of the pressure breaking point, reduce the discharge rate by 1 bpm and observe the pressure. Repeat this step-by-step reduction in discharge rate during filling, and continue to observe the pressure changes until sand begins to break down, at which point the filling operation is complete.

[0045] As can be seen from the above technical solution, the integrated sand control and water control completion string and completion process provided by the present invention have the following advantages:

[0046] This integrated sand control and water control completion string and process can ensure sand control while also meeting the water control needs during the production stage, achieving integrated sand control and water control during the completion phase. Simultaneously, during sand control filling in the completion phase, corresponding adaptive water control measures are implemented. In the early stages of development, this can balance production, increase the swept area, and extend the waterless production period. In the mid-stages of development, it can mitigate the problems of localized water inrush and premature high water cut caused by heterogeneity differences and root-toe effects in horizontal wells. In the later stages of development, it can slow down the rate of water cut increase, limit high water cut, and extend the development life of single wells.

[0047] Other features and advantages of the present invention will be set forth in the following description. Attached Figure Description

[0048] The accompanying drawings are provided to further understand the technical solutions of the present invention and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the technical solutions of the present invention, and do not constitute a limitation on the technical solutions of the present invention.

[0049] Figure 1 This is a schematic diagram of the integrated sand control and water control completion string in Embodiment 1 of the present invention;

[0050] Figure 2 This is a schematic diagram of the screen tube assembly in Embodiment 1 of the present invention;

[0051] Figure 3 This is a schematic diagram of the flow control coupling in Embodiment 1 of the present invention;

[0052] Figure 4 This is a process flow diagram of the well completion method in Embodiment 2 of the present invention;

[0053] Figure 5 This is a flowchart of step S8 in Embodiment 2 of the present invention;

[0054] Figure 6 This is a flowchart illustrating the design decision-making process for the well completion method in Embodiment 2 of the present invention.

[0055] Explanation of reference numerals in the attached figures:

[0056] 1. Wellbore isolation hanger; 2. Filling sleeve; 3. Sand control and water control assembly; 31. Screen pipe assembly; 32. Screen pipe base pipe; 33. Screen pipe coupling; 34. Flow control coupling; 35. Connector; 36. Screen sleeve assembly; 361. Outer end ring; 362. Inner end ring; 363. Filter sleeve; 37. Outer sleeve; 38. Adaptive flow control device; 4. Float shoe; 5. Open hole segmented packer; 6. First filter ring cavity; 7. Second filter ring cavity; 8. Connecting hole; 9. Mounting hole; 10. Sealing ring. Detailed Implementation

[0057] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present invention can be arbitrarily combined with each other.

[0058] Example 1

[0059] like Figure 1 , Figure 2 , Figure 3 The illustration shows Embodiment 1 of the present invention, which discloses an integrated sand control and water control completion string, comprising a wellbore isolation hanger 1, a filling sleeve 2, a sand control and water control assembly 3, and a float shoe 4 connected in sequence. In this embodiment, the wellbore isolation hanger 1 is located on the far left and is used to connect to the wellbore. Multiple open-hole segmented packers 5 are connected in sequence to the sand control and water control assembly 3. The open-hole segmented packers 5 are used to set on the formation to achieve formation isolation.

[0060] In one embodiment, such as Figure 1 , Figure 2 As shown, the sand control and water control assembly 3 includes multiple screen pipe assemblies 31 connected in sequence. Each screen pipe assembly 31 includes a screen pipe base pipe 32. The left end of each screen pipe base pipe 32 is threadedly connected to a screen pipe coupling 33, and the right end is threadedly connected to a flow control coupling 34. The right end of each flow control coupling 34 is integrally formed with a connector 35, and the connector 35 cooperates with the screen pipe coupling 33, that is, the connector 35 and the screen pipe coupling 33 on two screen pipe assemblies 31 can be threadedly connected.

[0061] In one embodiment, such as Figure 2 , Figure 3As shown, each screen tube base tube 32 is fitted with a screen sleeve assembly 36, and a first filter ring cavity 6 is formed between the screen sleeve assembly 36 and the screen tube base tube 32. An outer sleeve 37 is fitted at the connection position between each screen sleeve assembly 36 and the corresponding control coupling. The left end of the outer sleeve 37 is threaded to the corresponding screen sleeve assembly 36, and the right end is threaded to the corresponding flow control coupling 34, and a second filter ring cavity 7 is formed between the outer sleeve 37 and the corresponding flow control coupling 34.

[0062] In one embodiment, such as Figure 2 , Figure 3 As shown, each screen sleeve assembly 36 has a connecting hole 8 at its right end, which connects the first filter ring cavity 6 and the second filter ring cavity 7. Each flow control coupling 34 has multiple mounting holes 9, which are evenly spaced along the circumference of the coupling. Each mounting hole 9 connects the second filter ring cavity 7 to the inside of the screen tube base tube 32. Simultaneously, each mounting hole 9 is equipped with an adaptive flow control device 38 to adjust the flow rate.

[0063] When sand control is carried out, the filling medium and sand-carrying fluid enter the space between the completion string and the formation through the filling sliding sleeve 2. The filling medium is screened by the screen sleeve assembly 36, and the sand-carrying fluid enters the first filter ring cavity 6 through the screen sleeve assembly 36, then enters the second filter ring cavity 7 through the connecting hole 8, and enters the flow control coupling 34 through the adaptive flow control device 38, and finally exits through the screen pipe base pipe 32.

[0064] During production, the output liquid is filtered for the first time through the filling medium, then filtered for the second time through the screen sleeve assembly 36 and enters the first filter ring cavity 6. It then enters the second filter ring cavity 7 through the connecting hole 8, and enters the flow control coupling 34 through the adaptive flow control device 38. Finally, it is returned through the screen tube base tube 32.

[0065] In this embodiment, the adaptive flow control device 38 can automatically adjust the flow resistance coefficient and pressure drop according to the actual working conditions of the wellbore. During the filling process, it provides a return channel for the sand-carrying fluid and a flow channel for the produced fluid during the production process. It also increases the corresponding additional friction based on the water content of the produced fluid to control the production in the high water content section. This is the prior art and will not be described in detail here.

[0066] In one embodiment, such as Figure 2 , Figure 3 As shown, the outer sleeve 37, the screen sleeve assembly 36, and the flow control coupling 34 are sealed by sealing rings 10, thereby improving the sealing stability of the completion string. In this embodiment, the sealing ring 10 is preferably a temperature- and pressure-resistant sealing O-ring to ensure sealing stability.

[0067] In one embodiment, such as Figure 2 , Figure 3As shown, the screen sleeve assembly 36 includes an outer end ring 361, an inner end ring 362, and a filter sleeve 363. The outer end ring 361 and the inner end ring 362 are respectively fixedly sleeved on the screen tube base tube 32. The filter sleeve 363 is located between the outer end ring 361 and the inner end ring 362, with its left end connected to the outer end ring 361 and its right end connected to the inner end ring 362. Meanwhile, the left end of the outer sleeve 37 is threadedly connected to the inner end ring 362. Multiple connecting holes 8 are provided and are respectively provided through the inner end ring 362, thereby achieving communication between the first filter ring cavity 6 and the second filter ring cavity 7.

[0068] In this embodiment, the filter sleeve 363 includes a multi-layer mesh structure such as a support mesh, a drainage mesh, and a filter mesh, which is used to block formation sand and fill the medium to ensure the filtration effect.

[0069] In one embodiment, such as Figure 1 As shown, the open-hole segment packer 5 employs an oil- or water-swellable packer, an extrusion-expandable packer, or a compression-expandable packer to achieve independence of each producing layer within the open-hole segment and resolve interlayer conflicts. Of course, in other embodiments, the open-hole segment packer 5 can also employ other types of packers, which will not be listed in detail here.

[0070] Example 2

[0071] like Figure 4 , Figure 5 , Figure 6 The following is an embodiment 2 of the present invention, which discloses a well completion process method. This method uses the well completion string from embodiment 1 and includes the following steps:

[0072] S1, based on information such as the geological structure of the target well, well logging interpretation data, drilling conditions, formation fluid characteristics, production well history, and adjacent well data, analyzes and understands the oil well's production capacity, produced fluid ratio, and oil-water distribution.

[0073] S2, based on the reservoir properties distribution of the target well, open hole segment packers 5 are deployed at the property difference boundary, mudstone interlayer, and water-flooded section to isolate the formation, resolve interlayer conflicts, and prevent large-scale water flow.

[0074] S3. Based on the analysis of formation sand particle size, and the sand control parameters of adjacent wells in the same sand body and layer, select the sand-blocking accuracy and the size and type of filling medium of the sand control and water control assembly 3.

[0075] S4. Based on parameters such as the target well's production capacity, crude oil viscosity, permeability distribution, oil / water saturation, and formation pressure, select the arrangement method, number, and specifications of tubing strings for each production zone.

[0076] S5. Based on the data results from S1-S4, assemble the various components of the completion string.

[0077] S6, Run in the completion string, and set the wellbore isolation hanger 1 and multiple open hole segment packers 5 according to the construction design, and perform the hanging, sealing and release operations.

[0078] S7. Connect and pressure test the external filling equipment according to the construction design, and conduct squeezing test, forward circulation test and reverse circulation test.

[0079] S8. Based on the test results in S7, check the formation pressure failure, open the filling sleeve 2, and fill with gravel through external filling equipment until the set sand removal pressure is reached, and end the filling operation.

[0080] S9 adopts a method of slow frequency increase, frequent tracking, and frequent observation in the early stage of oil well production.

[0081] In S5, based on the data results from S1-S4, the length of the screen base pipe 32 in each layer is determined, as well as the number and installation position of the open-hole segment packers 5. This ensures that after the completion string is run, the open-hole segment packers 5 are located at the physical property difference boundary, mudstone interlayer, water-flooded section, and other corresponding locations. Simultaneously, based on the formation sand particle size, the screen aperture size of the filter sleeve 363 is selected, along with the particle size of the packing medium, ensuring that both the formation sand particle size and the packing medium particle size are larger than the screen aperture size of the filter sleeve 363.

[0082] In S3, the filling medium uses an organic polymer as aggregate, coated with a multi-layer resin film to improve the strength and smoothness of the particles. Simultaneously, the outermost resin film has a water contact angle >160° and an apparent density <1.05 g / cm³. 3 It exhibits good suspension properties in sand-carrying fluid, resulting in a large operating window and low operational risk.

[0083] like Figure 5 As shown, S8 includes the following steps:

[0084] S81, calculate the wellbore flow friction based on reverse circulation test, and calculate the formation fracture pressure through injection test. Determine 85% of the formation fracture pressure as the safe pressure limit based on the wellbore flow friction and the formation fracture pressure.

[0085] S82, calculate formation leakage based on positive circulation test, and back-calculate construction discharge volume by combining formation leakage and wellbore safety discharge volume;

[0086] S83, Select the filling pumping procedure for external filling equipment based on safety pressure limit and construction discharge capacity;

[0087] S84, filling operations are carried out using external filling equipment.

[0088] In S84, a stepped-down filling operation method is used, with pressure limited but not flow limited, to fill and compact the space between the reservoir and the completion string, as well as the reservoir void zone. S84 includes the following steps:

[0089] S841, start pumping at a filling displacement of 8-12 bpm and monitor the filling pressure in real time;

[0090] S842, if the formation pressure is less than 85% of the pressure breaking point, continue pumping; if the formation pressure is greater than 85% of the pressure breaking point, reduce the discharge rate by 1 bpm and observe the pressure. Repeat this step-by-step reduction in discharge rate during filling, and continue to observe the pressure changes until sand begins to break down, at which point the filling operation is complete.

[0091] like Figure 6 As shown, based on the existing sand control and water control designs, the formation data is analyzed, and the sand control method and filling medium size are optimized to ensure that the completion string can have both sand control and water control capabilities, thus deriving an adaptive integrated sand control and water control completion process scheme.

[0092] As described above, this integrated sand control and water control completion string, in locations with significant fluctuations in reservoir properties, mudstone interlayers, and water-flooded sections, rationally arranges open-hole segmented packers 5 to resolve interlayer conflicts. Simultaneously, the open-hole segmented packers 5 are equipped with sealing cylinders, providing wellbore conditions for segmented treatment of the central tubing. Furthermore, in the radial direction, this integrated sand control and water control completion string, through the combination of the flow-blocking layer of the filling medium and the adaptive screen arrangement, increases the flow friction of the produced fluid, controls high-water-cut and high-production sections within the formation, balances the impact, and achieves overall potential tapping. In the axial direction, through the cooperation of the blind end of the screen and the gravel filling layer, the capillary resistance and the seepage resistance of the porous medium are superimposed, mitigating water channeling.

[0093] This completion process allows for both gravel packing and water control in horizontal wells during the completion phase. It automatically adjusts the flow friction of the produced fluid based on the water cut, achieving balanced sweep and delaying water breakthrough in the early and mid-stages, while controlling water cut and slowing the rate of water cut increase in the later stages. Furthermore, this completion process employs a stepped reduction-flow packing method, filling the sand control and water control media at high velocity and pressure between the reservoir and the completion string, and into the formation void zone, thus meeting the development requirements of integrated water control and sand control completion for horizontal wells.

[0094] Therefore, the integrated sand control and water control completion string and completion process method in this embodiment have the following advantages:

[0095] (1) It can be carried out during the well completion stage or the secondary well completion (workover) stage. Compared with the conventional gravel packing well completion method, it does not increase the complexity of construction, the tubing structure is reliable, and no additional construction steps are added.

[0096] (2) By combining sand-proof and water-controlling filling medium with adaptive screen pipe, two-stage water blocking and two-stage sand blocking can be achieved, ensuring sand prevention while taking into account the water control needs of the production stage. The integrated management of sand prevention and water control can be achieved in the well completion stage.

[0097] (3) Compared with conventional cyclic filling, the step-down filling method has a higher pumping pressure and a denser particle arrangement in the filling layer, which can reduce the risk of hot spot erosion of the sand-blocking pipe, extend the service life of the tubing, and reduce the risk of sand discharge.

[0098] (4) The screen assembly 31 has a single length of 8-12m. The formation produced fluid production channel is single. In combination with the filling medium layer and the near-wellbore reservoir, it can slow down the flow of produced fluid around the wellbore and improve the effect of the second water barrier.

[0099] (5) The adaptive flow control device 38 has the ability to intelligently identify formation produced fluids with different viscosities, densities, compositions, and temperatures, which can improve the production efficiency and recovery rate of a single well.

[0100] It should be noted that, unless otherwise stated, the technical or scientific terms used in this invention should have the ordinary meaning as understood by one of ordinary skill in the art.

[0101] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly defined.

[0102] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A well completion string integrating sand control and water control, characterized in that, It includes a wellbore isolation hanger (1), a filling sleeve (2), a sand and water control assembly (3), and a float shoe (4) connected in sequence. Multiple open-hole segment packers (5) are connected in sequence on the sand and water control assembly (3) to achieve formation separation. The sand control and water control assembly (3) includes a plurality of screen pipe assemblies (31) connected in sequence, each of the screen pipe assemblies (31) comprising: Screen tube base tube (32); A screen pipe coupling (33) is connected to the end of the screen pipe base pipe (32); A flow control coupling (34) is connected to the end of the screen tube base pipe (32) away from the screen tube coupling (33); A connector (35) is provided at one end of the flow control coupling (34) away from the screen tube base tube (32), and the connector (35) cooperates with the screen tube coupling (33); The sieve sleeve assembly (36) is connected to the sieve tube base tube (32), and a first filter ring cavity (6) is formed between the sieve sleeve assembly (36) and the sieve tube base tube (32); The outer sleeve (37) is connected at one end to the screen sleeve assembly (36) and at the other end to the flow control coupling (34), and a second filter ring cavity (7) is formed between the outer sleeve (37) and the flow control coupling (34); A connecting hole (8) is provided on the sieve sleeve assembly (36) and connects the first filter ring cavity (6) and the second filter ring cavity (7); The mounting hole (9) is provided on the flow control coupling (34) and connects the second filter ring cavity (7) with the inside of the screen tube base tube (32); An adaptive flow control device (38) is disposed within the mounting hole (9).

2. The completion string according to claim 1, characterized in that, The mounting holes (9) are provided in a plurality of manner, and the plurality of mounting holes (9) are arranged at equal intervals along the circumference of the flow control coupling (34), and each mounting hole (9) is provided with an adaptive flow control device (38).

3. The completion string according to claim 1, characterized in that, The outer sleeve (37) is sealed to the screen sleeve assembly (36) and the flow control coupling (34) by sealing rings (10).

4. The completion string according to claim 1, characterized in that, The screen sleeve assembly (36) includes: The outer end ring (361) is fixed to the screen tube base tube (32); The inner end ring (362) is fixed to the screen tube base tube (32); A filter sleeve (363) is fitted onto the screen tube base tube (32). One end of the filter sleeve (363) is connected to the outer end ring (361), and the other end is connected to the inner end ring (362). The outer sleeve (37) is connected to the inner end ring (362), and the connecting hole (8) is disposed through the inner end ring (362).

5. The completion string according to claim 1, characterized in that, The naked-eye segmented packer (5) is an oil- or water-swellable packer, an extrusion-expandable packer, or a compression-expandable packer.

6. A well completion process method, using the well completion string according to any one of claims 1-5, characterized in that, The steps include: S1, based on the geological structure of the target well, well logging interpretation data, drilling conditions, formation fluid characteristics, production well history, and adjacent well data, analyzes and understands the oil well's production capacity, produced fluid ratio, and oil-water distribution. S2, combined with the reservoir properties distribution of the target well, open hole segment packers (5) are arranged at the property difference boundary, mudstone interlayer, and water-flooded section to isolate the formation, resolve interlayer contradictions, and prevent large-scale water flow. S3. Based on the analysis of formation sand particle size, the sand control parameters of adjacent wells in the same sand body and the same layer are selected to determine the sand control accuracy and the size and type of filling medium of the sand control and water control assembly (3). S4. Based on the target well's production capacity, crude oil viscosity, permeability distribution, oil / water saturation, and formation pressure parameters, select the arrangement method, number, and specifications of tubing strings for each production zone. S5. Based on the data results from S1-S4, assemble the various components of the completion string. S6, Run in the completion string, and set the wellbore isolation hanger (1) and multiple open hole segment packers (5) according to the construction design, and perform the hanging, sealing and release operations. S7. Connect and pressure test the external filling equipment according to the construction design, and conduct squeezing test, forward circulation test and reverse circulation test. S8. Based on the test results in S7, check the formation pressure failure, open the filling sleeve (2), and fill with gravel through external filling equipment until the set sand removal pressure is reached, and end the filling operation. S9 adopts a method of slow frequency increase, frequent tracking, and frequent observation in the early stage of oil well production.

7. The well completion process according to claim 6, characterized in that, In S3, the filling medium uses organic polymers as aggregates, coated with multiple layers of resin film, with the outermost resin film having a contact angle with water >160° and an apparent density <1.05 g / cm³. 3 .

8. The well completion process according to claim 6, characterized in that, S8 includes the following steps: S81, calculate the wellbore flow friction based on reverse circulation test, and calculate the formation fracture pressure through injection test. Determine 85% of the formation fracture pressure as the safe pressure limit based on the wellbore flow friction and the formation fracture pressure. S82, calculate formation leakage based on positive circulation test, and back-calculate construction discharge volume by combining formation leakage and wellbore safety discharge volume; S83, Select the filling pumping procedure for external filling equipment based on safety pressure limit and construction discharge capacity; S84, filling operations are carried out using external filling equipment.

9. The well completion process according to claim 8, characterized in that, In S84, a stepped reduction in discharge rate is adopted for the filling operation, which limits the pressure but not the discharge rate, to fill the gap between the reservoir and the completion string and the reservoir void zone densely.

10. The well completion process according to claim 9, characterized in that, S84 includes the following steps: S841, start pumping at a filling displacement of 8-12 bpm and monitor the filling pressure in real time; S842, if the formation pressure is less than 85% of the pressure breaking point, continue pumping; if the formation pressure is greater than 85% of the pressure breaking point, reduce the discharge rate by 1 bpm and observe the pressure. Repeat this step-by-step reduction in discharge rate during filling, and continue to observe the pressure changes until sand begins to break down, at which point the filling operation is complete.

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