Underground filling form detection method for filling sand prevention and experimental device thereof

Abstract

The invention discloses an underground filling form detection method for filling sand prevention and an experimental device thereof. The method comprises the following steps: S1, establishing a contrast database; s2, underground filling construction is carried out; s3, a detection instrument is put down to detect the underground filling form; s4, result analysis is carried out; and S5, a test result is corrected. According to the method, the underground filling form of filling sand prevention can be accurately detected, and the technical problem that the underground filling sand prevention form cannot be detected is innovatively solved. According to the method, a contrast database is innovatively established, the explanation accuracy of a detection result is further improved, and the method has important significance on sand prevention effect analysis and sand prevention design optimization in the next step. The filling form detection experiment device is innovatively designed, the design of the mold in the cavity of the device can be flexibly adjusted, filling forms of different filling parameters can be measured, and support is provided for forming an accurate underground filling form measurement method.

Description

Technical Field

[0001] The invention relates to the technical field of oil well sand control, in particular to a method for detecting the filling form of a filling sand control well and an experimental device thereof. Background Art

[0002] Currently, for long horizontal wells, a cyclic filling method is often used for sand control completion. For loose sandstone reservoirs, squeeze filling is often used to compensate for formation deficiencies, improve the strength of the sand barrier and the density of the sand packing, and extend the effective life of sand control. For low-permeability reservoirs, large-scale fracturing and filling sand control methods are often used to achieve a certain degree of formation transformation and improve the seepage capacity of the seepage channel. However, due to the lack of means to identify the filling status of the downhole oil layer, it is impossible to describe the downhole filling morphology of the filling sand control, and it is impossible to understand the whereabouts of specific proppants downhole. Therefore, it is impossible to accurately measure the true factors affecting the effectiveness of sand control. As a result, sometimes only theoretical speculation can be made, and the true root cause of poor results cannot be found, the excellent experience of good construction results cannot be effectively summarized, and accurate guidance for future improvements and optimization cannot be provided.

[0003] In response to these problems, the present invention provides a method for detecting the downhole filling morphology of filling and sand control and an experimental device thereof. The method first determines the detection results under different sand filling parameters through an experimental device, obtains the detection results through a large number of experiments, compares the detection results with the actual sand filling parameters, and analyzes the detection errors. On the one hand, the accuracy of the detection method is tested, and on the other hand, a reference database of the detection results corresponding to different filling parameters is formed through correction; then, filling and sand control operations are performed, and proppants with special functions are filled into the formation during the actual filling and sand control operations; then, detection is performed through downhole detection instruments, and the detection results are compared and analyzed with the reference database to obtain the downhole filling morphology.

[0004] Currently, tracer methods are commonly used for downhole monitoring of oil wells, primarily for monitoring residual oil saturation, interwell connectivity of water injection wells, and stratified injection conditions. However, this technology analyzes downhole conditions using tracers contained in surface produced fluids and is unable to quantitatively describe the filling morphology of sand control packing.

[0005] Publication (Announcement) No.: CN112177570A discloses a gravel-packed sand control well squeeze filling morphology simulation experimental device, including a simulated wellbore system, a filling simulation system, a waste liquid recovery system and a pressure testing system. The simulated wellbore system includes a simulated formation boundary, a simulated wellbore, a simulated casing, a simulated oil pipe and a simulated core; the filling simulation system includes a water tank, a sand mixing tank, a filling pump and a simulated filling pipe string installed in the simulated wellbore. The invention also discloses an experimental method for the experimental device. The invention can highly simulate the downhole squeeze filling construction conditions, study the gravel layer squeeze filling morphology of various types of loose sandstone reservoirs under different well conditions and construction parameters, and the influence of the longitudinal heterogeneity of loose sandstone reservoirs on the gravel layer squeeze filling morphology, and provide a basis for the construction plan and process parameter optimization of sand control well gravel filling operations under different conditions based on the experimental results.

[0006] This prior art cannot achieve morphological simulation of different working conditions and cannot detect the underground filling morphology.

[0007] Publication (Announcement) No.: CN114878304A, discloses a new type of on-site strength detection device for filling bodies and its detection method, including a penetrometer, a penetration depth measuring instrument and a new type of on-site strength detection method for filling bodies, which only requires penetration force detection on the surface of the filling body, and the pressure range that the underground filling body can withstand can be inferred through a special strength measurement curve, without excavating the filling body and making another experimental filling body, thereby ensuring the integrity of the filling body to the greatest extent, and since the detection base is directly detected on the plane of the filling body, the detection accuracy is improved, and the deviation in the production process of the experimental filling body is avoided; and no instrument needs to be installed underground, only the instrument detection relies on its internal pressurized spring to load the measuring nail into the filling body, and the depth of the measuring nail penetration is measured. No additional power such as wind, water, and electricity is required during the detection process, and no waste gas, dust or sewage will be generated, which has a positive impact on the environment and also protects the health of the detection personnel.

[0008] This technology cannot detect the filling morphology of sand control filling wells.

[0009] Publication (Announcement) No. CN219061599U discloses a multifunctional downhole formation sand control performance evaluation device. Formation and completion characteristics are simulated using a formation simulator. An inner tube support frame, an outer tube support frame, and a kettle are sequentially arranged on the outside of the sand control tube. Artificial formations are filled between the inner and outer tube supports, and experimental media are filled between the kettle and outer tube supports. The experimental media enters the kettle through the medium inlet, passes through the outer tube support frame, the artificial formation, the inner tube support frame, and the sand control tube, and is discharged from the medium outlet of the bottom seal. A condenser and separator condense and separate the experimental media and sand discharged from the medium outlet, and an injection pump provides the experimental media driving pressure. A measuring device measures the internal pressure of the formation simulator, as well as the weight and flow rate of the experimental media flowing in and out. A data acquisition and processing device collects and displays the data measured by each device, thereby simulating different completion methods and sand control parameters and effectively evaluating the performance of each sand control component.

[0010] This prior art is unable to simulate and detect different filling forms.

[0011] In short, the technical solutions, technical problems to be solved and beneficial effects produced by the above-mentioned disclosed technologies are all different from the present invention. Regarding more technical features, technical problems to be solved and beneficial effects of the present invention, the above-mentioned disclosed technical documents do not provide any technical inspiration. Summary of the Invention

[0012] To address the aforementioned shortcomings of the prior art, the present invention provides a method and experimental device for detecting downhole filling morphology for sand filling control. This method first utilizes an experimental device to measure the test results under different sand filling parameters, and through extensive testing, a reference database is generated. Sand filling operations are then performed, along with the use of a proppant with specialized properties. Downhole testing instruments are then used to perform testing, and the test results are compared and analyzed with the reference database to determine the downhole filling morphology. This technology can accurately detect the filling morphology of downhole sand filling control, which is of great significance for analyzing the effectiveness of filling sand control and subsequently designing and optimizing sand filling parameters.

[0013] In order to achieve the above object, the present invention adopts the following technical solutions:

[0014] A method for detecting the filling morphology of a filling sand control well comprises the following steps:

[0015] S1. Establish a control database; first, make a filling mold according to the filling sand control filling form, and the material of the filling mold does not affect the detection signal. Fill the filling mold with a specific proppant according to the required filling parameters, and fill it with simulated formation sand around it. The particle size and porosity of the simulated formation sand are simulated according to the formation parameters, and the sand is compacted with a binder to ensure that it is not loose.

[0016] After the test, the filling material is broken up and taken out with a debonding agent, and the filling shape detection experimental device can be reused;

[0017] Since the filling part inside the cavity is adjustable, different filling forms can be flexibly simulated according to different filling methods and filling parameters. By testing the filling layers of various filling forms and comparing the test results with the actual filling forms, a more complete and accurate comparison database can be obtained.

[0018] S2, carry out underground filling construction;

[0019] S3. Run the detection instrument to detect the filling shape in the well;

[0020] S4. Analyze the results: Analyze the test results obtained by the instrument to obtain preliminary test results;

[0021] S5. Test result correction: Compare the test results with the reference database to more accurately determine the filling form of the sand control well and obtain the corrected final test results.

[0022] Furthermore, when establishing a control database, the filling radius and filling thickness of the theoretical model of filling morphology will have many variations due to different filling parameters;

[0023] Specifically, in the in-pipe circulating filling, the filling radius is the distance from the outer wall of the screen to the inner wall of the casing, and the filling thickness is the length of the screen. However, along the entire length of the screen, the filling radius of the filling layer varies because the actual filling may not be dense.

[0024] Specifically, in the outer-tube circulation filling, the filling radius is the distance between the outer wall of the casing in the oil layer perforation section and the open hole wall, and the filling thickness is the length of the oil layer perforation section;

[0025] Specifically, in squeeze filling, the filling radius of a casing perforated well is the distance between the outer wall of the casing in the perforated section of the oil layer and the outer edge of the filling layer squeezed into the oil layer, and its filling thickness is the length of the perforated section of the oil layer;

[0026] Specifically, in an open hole well, the circulating filling radius is the distance between the outer edge of the oil layer wellbore and the open hole wall, and the filling thickness is the length of the oil layer section.

[0027] Furthermore, when establishing a reference database, the filling method of the filling morphology theoretical model includes one or at least two of segmented filling, layered filling, cyclic extrusion filling, cyclic filling, and extrusion filling.

[0028] Furthermore, during underground filling construction:

[0029] A1. Wellbore pretreatment: clean the wellbore;

[0030] A2. Backwash well: If acid washing, acidizing or other acid-related construction has been carried out before filling and sand control, the well must be fully backwashed during filling and sand control, and the return fluid at the outlet must be neutral;

[0031] A3. Filling with specific proppant;

[0032] Specifically, when different detection technologies are used to detect downhole filling morphology, specific proppants are designed and matched accordingly based on the detection principles.

[0033] Furthermore, when using a detection instrument using magnetic measurement technology to detect downhole filling morphology, the specific proppant is designed as a crown proppant;

[0034] Specifically, the crown proppant includes a proppant body, which is designed as a spherical structure; at least two crown support ribs are provided on the surface of the proppant body, and an induction enhancement layer is provided on the surface of the crown support ribs, and the end of each crown support rib is larger than the area of ​​the support rib gap formed between the crown support ribs;

[0035] Specifically, the crown proppant can generate an induced magnetic field due to the external induction enhancement layer, and the induced magnetic field signal can be collected to determine the downhole position of the specific proppant;

[0036] Specifically, the induction enhancement layer is a spherical shell formed by bonding metal powder and a binder to the outer layer of the proppant body and uniformly filling the gaps between the crown-shaped support ribs.

[0037] Specifically, the induction enhancement layer of the crown proppant can be removed by reacting with acid. After removal, it does not affect the strength of the specific proppant, does not cause the proppant packing layer to collapse, and increases the porosity of the proppant interstices, thereby enhancing the seepage capacity of underground fluids.

[0038] Specifically, after the filling morphology test is completed, acidification is performed. According to the filling amount of the crown proppant, a certain amount of acid is squeezed into the formation and soaked to clean and remove the induction enhancement layer wrapped around the outside of the crown proppant, and then the well is fully backwashed.

[0039] In order to achieve the above object, the present invention adopts the following technical solutions:

[0040] An experimental device for a method for detecting filling morphology of filled sand-control wells consists of an upper unit and a lower unit with identical and symmetrical structures; the upper unit or the lower unit includes a filling chamber, which is a rectangular shell with an open bottom and a filling chamber cavity inside, and a filling chamber cover is provided at the bottom of the filling chamber; the filling chamber cover is provided with a filling chamber cover cavity in the filling chamber projection area, and the filling chamber cavity is connected with the filling chamber cover cavity to form a cavity; the upper unit and the lower unit are spliced ​​together, and the spliced ​​filling chamber cover is provided with a test through hole passing through the spliced ​​surface, and the test through hole is used for inserting a test instrument for detection, or for simulating hanging filtration cycle filling by first inserting a sand control screen pipe and then inserting a test instrument for detection; the inner diameter of the test through hole is greater than the outer diameter of the wellbore size.

[0041] Furthermore, the filling chamber and the filling chamber cover are integrated and made of non-metallic material.

[0042] Furthermore, the filling chamber cover is provided with filling chamber fastening bolts, and the filling chamber fastening bolts are provided on the four corners of the filling chamber cover.

[0043] Furthermore, the left and right ends of the filling chamber cover are both provided with fastening bosses, and each fastening boss is provided with a boss fastening bolt.

[0044] Furthermore, the filling chamber cavity height + the filling chamber cover cavity height > the filling radius; the filling chamber cavity width > the filling thickness.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] 1. The present invention can accurately detect the filling shape of underground filling and sand control, and innovatively solves the technical problem that the underground filling and sand control shape cannot be detected.

[0047] 2. The present invention innovatively designs a filling morphology detection experimental device. The design of the fillable part of the mold inside the cavity of the device adopts a flexibly adjustable design, which can be used to measure the filling morphology of different filling parameters, providing support for the formation of an accurate downhole filling morphology measurement method.

[0048] 3. The present invention proposes a proppant with special functions, designs different sensing layers for different testing technologies, improves the response level, and provides a basis for downhole filling morphology detection.

[0049] 4. The present invention innovatively establishes a control database, which further improves the accuracy of the interpretation of the test results and is of great significance for the subsequent analysis of sand control effects and optimization of sand control design. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is a structural schematic diagram of an experimental device for detecting the filling morphology of a filling sand control downhole according to the present invention;

[0051] Figure 2 This is a front view of a full cross-section of an experimental device for detecting the filling form of a filling sand control downhole according to the present invention;

[0052] Figure 3 It is a side view of a full cross-section of an experimental device for detecting the filling form of a filling sand control downhole according to the present invention;

[0053] Figure 4 It is a schematic diagram of the theoretical model of extrusion filling morphology;

[0054] Figure 5 It is a schematic diagram of the theoretical model of the circulating filling morphology in the tube;

[0055] Figure 6 This is a schematic diagram of the theoretical model of the outer tube circulation filling morphology;

[0056] Figure 7 This is a schematic diagram of the theoretical model of extrusion filling morphology Figure 1 ;

[0057] Figure 8 This is a schematic diagram of the theoretical model of extrusion filling morphology Figure 2 ;

[0058] Figure 9 It is a schematic diagram of the theoretical model of extrusion cycle filling morphology;

[0059] Figure 10 This is a schematic diagram of the structure of the crown proppant in Example 2 of the present invention. Figure 1 ;

[0060] Figure 11 This is a schematic diagram of the structure of the crown proppant in Example 2 of the present invention. Figure 2 ;

[0061] In the figure: 1. Filling chamber; 2. Filling chamber cover; 3. Filling chamber fastening bolt; 4. Test through hole; 5. Fastening boss; 6. Boss fastening bolt; 7. Cavity; 8. Filling mold; 9. Screen or casing perforation section; 10. Filling layer; 11. Proppant body; 12. Crown support ribs; 13. Induction enhancement layer; 14. Support rib gap; L1, Filling chamber cavity width; L2, Filling chamber cover cavity width; R, Filling radius; R1, Test through hole inner diameter; R2, Distance from casing outer wall to outer edge of filling layer squeezed into oil layer; H1, Filling chamber cavity height; H2, Filling chamber cover cavity height; D, Filling thickness. DETAILED DESCRIPTION

[0062] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0063] Example 1:

[0064] See also Figures 1 to 4 The present invention provides an experimental device for detecting the filling morphology of a filled sand control well, which consists of an upper unit and a lower unit with identical and symmetrical structures. The upper unit or the lower unit includes a filling chamber 1, which is a rectangular shell with an open bottom and a filling chamber cavity inside. A filling chamber cover 2 is provided at the bottom of the filling chamber 1, and a filling chamber cover cavity is provided on the projection area of ​​the filling chamber 1. The filling chamber cavity is connected to the filling chamber cover cavity to form a cavity 7.

[0065] The filling chamber 1 and the filling chamber cover 2 are integrated and made of non-metallic material.

[0066] The filling chamber cover 2 is provided with at least two filling chamber fastening bolts 3. Specifically, the filling chamber fastening bolts 3 are provided on the four corners of the filling chamber cover 2, with a total of four bolts, for fixing the symmetrical two-part filling morphology detection experimental device together.

[0067] The upper unit and the lower unit are assembled together, and the assembled filling chamber cover 2 is provided with a test hole 4 which passes through the assembled surface. The test hole 4 is used for inserting a test instrument for detection, and can also be used for simulating the hanging filter cycle filling by first inserting a sand control screen pipe and then inserting a test instrument for detection. The inner diameter of the test hole 4 is greater than the outer diameter of the 7-inch wellbore size.

[0068] The left and right ends of the filling chamber cover 2 are both provided with fastening bosses 5 , and each fastening boss 5 is provided with a boss fastening bolt 6 for further fastening the two parts of the filling form detection experimental device.

[0069] The cavity 7 can be filled with corresponding fillers as needed and can withstand a certain pressure, wherein the filling chamber cavity height H1 + the filling chamber cover cavity height H2 > the filling radius R, and the filling chamber cavity width L1 > the filling thickness D.

[0070] The interior of the cavity 7 can be filled with a filling mold 8. Before testing, Figures 5 to 9 But not limited to Figures 5 to 9The filling mold 8 is made of the filling sand-proof filling form shown, and the material of the filling mold 8 does not affect the detection signal. The specific proppant is filled in the filling mold 8 according to the required filling parameters (such as filling amount, particle size ratio, etc.); and simulated formation sand is filled around it, wherein the particle size of the simulated formation sand, the porosity after cementation and other parameters are simulated according to the formation parameters, and the cementing agent is used to cement and compact it to ensure that it is not loose; after the test is completed, the filler can be broken up and taken out with a debonding agent, and the filling form detection experimental device can be reused.

[0071] Since the filling part inside the cavity is adjustable, different filling forms can be flexibly simulated according to different filling methods and filling parameters. There are many filling forms, and different filling forms can be referred to Figures 5 to 9 , but not limited to Figures 5 to 9 By testing filling layers with different filling forms, the test results are compared with the actual filling forms to obtain a more complete and accurate comparison database.

[0072] Example 2:

[0073] Based on Example 1, this embodiment provides a method for detecting the filling morphology of a filling sand control well, comprising the following steps:

[0074] S1. Establish a control database; Figure 1 、 Figure 2 、 Figure 3 ,The filling radius R and filling thickness D of the filling morphology theoretical model will have many changes due to different filling parameters;

[0075] Generally speaking, for in-pipe circulating filling, the filling radius R is the distance from the outer wall of the screen to the inner wall of the casing, and the filling thickness D is approximately the length of the screen. However, along the entire length of the screen, the filling layer may not be densely packed, so the filling radius R varies.

[0076] Similarly, for external circulation filling, the filling radius R is the distance between the outer wall of the casing in the oil layer perforation section and the open hole wall, and the filling thickness D is approximately the length of the oil layer perforation section;

[0077] Similarly, for squeeze filling, the filling radius R of the cased perforated well is the distance R2 between the outer wall of the casing in the perforated section of the oil layer and the outer edge of the filling layer squeezed into the oil layer, and the filling thickness D is approximately the length of the perforated section of the oil layer;

[0078] The circulating filling radius of an open hole well is the distance between the outer edge of the oil layer wellbore and the open hole wall. The filling radius of squeeze filling can reach about 4m, and its filling thickness D is approximately the length of the oil layer section.

[0079] In the actual sand control implementation process, due to the different physical properties of the reservoir, or when the oil layer of the reservoir is far away, the segmented filling method will be adopted. Therefore, there will be two layers of squeeze filling (such as Figure 8 e) Three-layer extrusion filling form (such as Figure 8 f, 9h) of the layered filling situation, similarly, the cycle extrusion filling is a combination of the cycle filling and extrusion filling processes;

[0080] According to the different filling parameters of the above filling processes, the underground filling morphology is ever-changing. In order to better simulate the underground filling morphology under different parameters, when establishing a large-scale physical model test, it is necessary to set up more experimental devices with different filling thicknesses and corresponding filling radii to obtain more test data to establish a control database;

[0081] This is of great significance for more accurate analysis and test results;

[0082] When establishing a control database, before testing, Figure 3 The filling mold 8 is made of the filling sand control filling form shown, and the material of the filling mold 8 does not affect the detection signal. The specific proppant is filled in the filling mold 8 according to the required filling parameters (such as filling amount, particle size ratio, etc.);

[0083] The surrounding area is filled with simulated formation sand, where the particle size of the simulated formation sand, the porosity after cementation and other parameters are simulated according to the formation parameters, and the sand is compacted with a cementing agent to ensure that it is not loose. After the test is completed, the filling material can be broken up and removed with a debonding agent, and the filling morphology detection experimental device can be reused;

[0084] Since the filling portion inside the cavity 7 is adjustable, different filling forms can be flexibly simulated according to different filling parameters;

[0085] There are many filling forms, and you can refer to different filling forms. Figures 5 to 9 , but not limited to Figures 5 to 9 ;

[0086] By testing filling layers with various filling forms, the test results are compared with the actual filling forms to obtain a more complete and accurate comparison database;

[0087] S2, carry out underground filling construction;

[0088] A1. Wellbore pretreatment: clean the wellbore;

[0089] A2. Backwash well: If acid washing, acidizing or other acid-related construction has been carried out before filling and sand control, the well must be fully backwashed during filling and sand control, and the return fluid at the outlet must be neutral;

[0090] A3. Filling with specific proppant. Specific proppant refers to proppant with special functions.

[0091] When using different detection technologies to detect downhole filling morphology, specific proppants can be designed and matched accordingly based on the detection principles;

[0092] S3. Run the detection instrument to detect the filling shape in the well;

[0093] S4. Analyze the results: Analyze the test results obtained by the instrument to obtain preliminary test results;

[0094] S5. Test result correction: Compare the test results with the reference database to more accurately determine the filling form of the sand control well and obtain the corrected final test results.

[0095] This method enables accurate detection of downhole filling morphology for sand filling control. It first conducts large-scale ground model tests, using detection instruments to measure the test results at different sand filling strengths. Through numerous tests, a control database is formed. Then, filling sand control operations are performed, and specific proppants with special functions are added to the formation during the actual filling sand control operation. Downhole detection instruments are then used to conduct tests, and the test results are compared and analyzed with the control database to obtain the downhole filling morphology, including proppant distribution and quantitative detection of specific morphology. This technology provides strong technical support for accurately grasping the specific implementation of filling sand control, analyzing the implementation effects and influencing factors, and achieves a new breakthrough in the detection of filling morphology for downhole sand filling control.

[0096] Example 3:

[0097] In Example 2, when different detection technologies are used to detect downhole filling morphology, specific proppants can be designed and matched accordingly based on the detection principle;

[0098] For example, magnetic detection technology can be used to detect the filling shape of the downhole, and the specific proppant can be designed as a crown proppant, such as Figure 10 、 11 As shown, the crown proppant includes a proppant body 11, which is designed as a spherical structure; at least two crown support ribs 12 are provided on the surface of the proppant body 11, and an induction enhancement layer 13 is provided on the surface of the crown support rib 12. Due to the external induction enhancement layer 13, the crown proppant can generate a strong induced magnetic field. The induced magnetic field signal can be collected to determine the downhole position of the specific proppant;

[0099] The end of each crown-shaped rib 12 is larger than the area of ​​the rib gap 14 formed between the ribs 12. This means that the end of each crown-shaped rib cannot be inserted into the rib gap formed between the crown-shaped ribs of other proppant particles. This ensures that when the induction enhancement layer wrapped around the outer layer is removed, it will not cause the proppant pack to collapse, thereby maintaining the permeability of the proppant pack.

[0100] The induction enhancement layer 13 is made of metal powder (which can be aluminum) bonded to the outer layer of the proppant body with a binder, and is evenly filled in the gaps between the crown-shaped support ribs to form a spherical shell.

[0101] The induction enhancement layer can generate a stronger induction signal that is different from the rock layer in the formation when performing magnetic detection in the well;

[0102] Moreover, the induction enhancement layer 1 of the crown proppant can be removed by reacting with acid without affecting the strength of the specific proppant. At the same time, due to the design of the crown support rib structure, after the induction enhancement layer is removed, the proppant filling layer will not collapse, and the porosity of the support rib gap 14 can be increased to a certain extent, thereby enhancing the seepage capacity of the underground fluid.

[0103] After completing the filling morphology test, acidification is performed. According to the filling amount of the crown proppant, a certain amount of acid is squeezed into the formation and soaked for 8 hours. The induction enhancement layer wrapped around the outside of the crown proppant is cleaned and removed, and then the well is fully backwashed.

[0104] Similarly, different detection methods can design corresponding sensing enhancement layers.

[0105] All components not discussed in detail in this application and the connection methods of the components in this application are well-known technologies in the technical field and can be directly applied without further explanation.

[0106] In the present invention, the term "plurality" refers to two or more, unless otherwise specified. Terms such as "installed," "connected," "connected," and "fixed" should be interpreted broadly. For example, "connected" can mean fixed, removable, or integral; and "connected" can mean directly or indirectly through an intermediary. Those skilled in the art will understand the specific meanings of these terms in the present invention based on specific circumstances.

[0107] In the description of the present invention, it should be understood that the directions or positional relationships indicated by terms such as "up", "down", "left", "right", "front" and "back" are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limiting the present invention.

[0108] Throughout this specification, terms such as "one embodiment," "some embodiments," and "specific embodiments" mean that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0109] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A method for detecting the filling morphology of a filling sand control well, characterized in that: The following steps are included: S1. Establish a control database; first, make a filling mold according to the filling sand control filling form, and the material of the filling mold does not affect the detection signal. Fill the filling mold with a specific proppant according to the required filling parameters, and fill it with simulated formation sand around it. The particle size and porosity of the simulated formation sand are simulated according to the formation parameters, and the sand is compacted with a binder to ensure that it is not loose. After the test, the filling material is broken up and taken out with a debonding agent, and the filling shape detection experimental device can be reused; Since the filling part inside the cavity is adjustable, different filling forms can be flexibly simulated according to different filling methods and filling parameters. By testing the filling layers of various filling forms and comparing the test results with the actual filling forms, a more complete and accurate comparison database can be obtained. S2, carry out underground filling construction; S3. Run the detection instrument to detect the filling shape in the well; S4. Analyze the results: Analyze the test results obtained by the instrument to obtain preliminary test results; S5. Test result correction: Compare the test results with the reference database to more accurately determine the filling form of the sand control well and obtain the corrected final test results.

2. A method for detecting underground filling morphology for filling and sand control according to claim 1, characterized in that: When establishing a control database, the filling radius and filling thickness of the filling morphology theoretical model will vary greatly due to different filling parameters; In the in-pipe circulation filling, the filling radius is the distance from the outer wall of the screen to the inner wall of the casing, and the filling thickness is the length of the screen. However, along the entire length of the screen, the filling radius of the filling layer varies because the actual filling may not be dense. In the external circulation filling, the filling radius is the distance between the outer wall of the casing in the oil layer perforation section and the open hole wall, and the filling thickness is the length of the oil layer perforation section; In squeeze filling, the filling radius of a casing perforated well is the distance between the outer wall of the casing in the perforated section of the oil layer and the outer edge of the filling layer squeezed into the oil layer, and the filling thickness is the length of the perforated section of the oil layer; In an open hole well, the circulating filling radius is the distance between the outer edge of the oil layer wellbore and the open hole wall, and the filling thickness is the length of the oil layer section.

3. A method for detecting underground filling morphology for filling and sand control according to claim 1, characterized in that: When establishing a reference database, the filling methods of the filling morphology theoretical model include one or at least two of segmented filling, layered filling, cyclic extrusion filling, cyclic filling, and extrusion filling.

4. A method for detecting underground filling morphology for filling and sand control according to claim 1, characterized in that: During underground filling construction: A1. Wellbore pretreatment: clean the wellbore; A2. Backwash well: If acid washing, acidizing or other acid-related construction has been carried out before filling and sand control, the well must be fully backwashed during filling and sand control, and the return fluid at the outlet must be neutral; A3. Filling with specific proppant; When using different detection technologies to detect downhole filling morphology, specific proppants are designed and matched accordingly based on the detection principles.

5. A method for detecting underground filling morphology for filling and sand control according to claim 1, characterized in that: When using a magnetic measurement technology detection instrument to detect downhole filling morphology, the specific proppant is designed as a crown proppant; The crown proppant comprises a proppant body, which is designed as a spherical structure; at least two crown support ribs are provided on the surface of the proppant body, and an induction enhancement layer is provided on the surface of the crown support ribs, and the end of each crown support rib is larger than the area of ​​the support rib gap formed between the crown support ribs; The crown proppant can generate an induced magnetic field due to the external induction enhancement layer, and the induced magnetic field signal can be collected to determine the downhole position of the specific proppant; The induction enhancement layer is a spherical shell formed by bonding metal powder and a binder to the outer layer of the proppant body and uniformly filling the gaps between the crown-shaped support ribs. The induction enhancement layer of the crown proppant can be removed by reacting with acid. After removal, the strength of the specific proppant will not be affected, and the proppant filling layer will not collapse. In addition, the porosity of the support rib gaps will be increased, thereby enhancing the seepage capacity of underground fluids. After completing the filling morphology test, acidification is performed. According to the filling amount of the crown proppant, a certain amount of acid is squeezed into the formation and soaked. The induction enhancement layer wrapped around the outside of the crown proppant is cleaned and removed, and then the well is fully backwashed.

6. An experimental device for detecting the filling morphology of a filling sand control well, characterized in that: It consists of two parts, the upper unit and the lower unit, which are identical and symmetrical in structure; The upper unit or the lower unit includes a filling chamber, which is a rectangular shell with an open bottom and a filling chamber cavity inside. A filling chamber cover is provided at the bottom of the filling chamber; The filling chamber cover is provided with a filling chamber cover cavity in the filling chamber projection area, and the filling chamber cavity is connected with the filling chamber cover cavity to form a cavity; The upper unit and the lower unit are assembled together, and a test hole is set on the assembled filling chamber cover, which passes through the assembled surface. The test hole is used to insert a test instrument for testing, or to insert a sand control screen first and then insert a test instrument for testing when simulating the hanging filter cycle filling; The inner diameter of the test through hole is greater than the outer diameter of the wellbore size.

7. The experimental device for detecting the filling morphology of a filling sand control well according to claim 6, characterized in that: The filling chamber and the filling chamber cover are integrated and are made of non-metallic material.

8. The experimental device for detecting the filling morphology of a filling sand control well according to claim 6, characterized in that: The filling chamber cover is provided with filling chamber fastening bolts, and the filling chamber fastening bolts are arranged on the four corners of the filling chamber cover.

9. The experimental device for detecting the filling morphology of a filling sand control well according to claim 6, characterized in that: The left end and the right end of the filling chamber cover are both provided with fastening bosses, and each fastening boss is provided with a boss fastening bolt.

10. The experimental device for detecting the filling morphology of a filling sand control well according to claim 6, characterized in that: Filling chamber cavity height + filling chamber cover cavity height > filling radius; filling chamber cavity width > filling thickness.

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