A horizontal well completion method integrating segmented reconstruction and production profile testing

Abstract

The present application belongs to the field of oil and gas field exploration and development, and relates to a horizontal well completion method integrating segmented reconstruction and production profile testing. The method of the present application adopts solid chemical tracers which are easily placed into a casing sliding sleeve. Before the casing sliding sleeve is opened, the built-in solid chemical tracers are not in contact with injection fluid and formation fluid, and are in a sealed state. After the casing sliding sleeve is opened, when the fracturing fluid flows through the casing sliding sleeve, the solid chemical tracers are released by contacting the fluid, and directly enter the reservoir together with the fracturing fluid. This method avoids the situation that, when tracers are added at the wellhead, each type of tracer needs to flow through the entire horizontal wellbore, and various types of tracers are left in the horizontal section, thereby ensuring the accuracy of the later testing.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas field exploration and development. Specifically, it relates to hydraulic fracturing technology, which is a horizontal well completion method that integrates staged stimulation and production profile testing. Background Technology

[0002] Horizontal well staged fracturing is a crucial technique for increasing single-well production in low-permeability to tight oil and gas reservoirs, both domestically and internationally. Due to reservoir heterogeneity, the fluid production of each stage in a horizontal well varies considerably, sometimes significantly. In some stages, the fluid contribution can exceed 40% of the total well production, while others may contribute nothing. Analyzing the reservoir characteristics of these anomalous stages is essential for sweet spot classification and personalized parameter optimization design in the subsequent development of stimulation plans for horizontal wells in this block. Rapid, low-cost, and accurate production profile testing is fundamental for identifying various reservoir types and analyzing production patterns.

[0003] Currently, the chemical tracer production profile testing method used both domestically and internationally involves manually adding tracers from the surface into the wellbore during fracturing using specialized equipment. This method involves two separate systems: the fracturing injection system and the tracer addition system. The addition process is complex, requires numerous supporting equipment, and incurs high manpower, material resources, and costs. Furthermore, each stage of tracer addition involves flowing through the wellbore, resulting in various types of tracers remaining in the horizontal sections. This leads to reduced accuracy and reliability of results during flowback and sampling analysis during production.

[0004] The invention, with publication number CN113027430A, is titled "A Horizontal Well Production Profile Testing String and Process Based on Tracer Labeling." It employs an intelligent switch to automatically control its opening and closing, enabling multi-segment horizontal well profile testing, thus improving interpretation accuracy. However, it suffers from drawbacks: a complex testing process, numerous supporting equipment, and the need to run a specialized testing string when testing horizontal well production profiles. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a horizontal well completion method that integrates segmented fracturing and production profile testing. This method solves the problems of complex chemical tracer testing and injection processes, numerous supporting equipment, high manpower and material resources, high costs, and low accuracy in current methods. It truly integrates fracturing and production profile testing, significantly simplifying the operation process, improving operational efficiency and testing accuracy, and reducing overall costs.

[0006] The technical solution of the present invention is as follows:

[0007] A horizontal well completion method integrating staged stimulation and production profile testing includes the following steps:

[0008] Step 1: The horizontal well is modified using staged fracturing technology. During the casing running process after the horizontal well drilling is completed, multiple casing sleeves are spaced apart on the well casing and run into the horizontal well together with the well casing. Each casing sleeve contains a solid chemical tracer. The types of solid chemical tracers in each casing sleeve are different.

[0009] Step 2: During each fracturing stimulation of a horizontal well, a ball is dropped from the surface into the wellbore to open the casing sleeve. Then, fracturing fluid and proppant are injected. As the fracturing fluid flows through the casing sleeve, the solid chemical tracer dissolves into the fracturing fluid and enters the reservoir along with the fracturing fluid.

[0010] Step 3: Repeat step 2 to complete the fracturing of all sections of the horizontal well, shut in the well, wait for the injected soluble balls to completely dissolve and restore the wellbore channel, and then open the well to enter flowback and production;

[0011] Step 4: Continuously collect produced fluid samples from different fracturing sections at the wellhead for analysis. Identify the types of solid chemical tracers contained in each sample and quantify the proportion of each solid chemical tracer to obtain the production profile of the entire horizontal well.

[0012] Furthermore, the number of casing sleeves is the same as the number of sections in the horizontal well fracturing, and each section in the horizontal well corresponds to one casing sleeve.

[0013] Furthermore, the types of solid chemical tracers in all the casing sleeves of the horizontal well are different, and the types of solid chemical tracers are the same as the number of fracturing sections of the horizontal well.

[0014] Furthermore, the volume ratio of the fracturing fluid to the proppant is 5 to 7:1.

[0015] Furthermore, before the casing sleeve is opened, its built-in solid chemical tracer does not come into contact with the injected fluid or the formation fluid, and is in a sealed state.

[0016] Furthermore, after all sections of the horizontal well have been fracturing, during the flowback and production processes, the solid chemical tracers from each section are brought to the surface along with the produced fluid after entering the wellbore.

[0017] Furthermore, the solid chemical tracer is a halogenated aromatic compound.

[0018] Furthermore, the location of each modified section was obtained by using well logging methods.

[0019] The beneficial effects of this invention are: it integrates fracturing and production profile testing, significantly simplifies the operation process, improves operation efficiency and testing accuracy, and reduces overall costs.

[0020] This invention employs a casing sliding sleeve that corresponds to the fracturing section. When the casing sliding sleeve of each section is opened, it provides a fluid flow channel for the fracturing transformation of that section. At the same time, the solid chemical tracer built into each casing sliding sleeve enters the reservoir with the fracturing fluid of that section and becomes a marker of the fluid returned from that section.

[0021] This invention utilizes a solid chemical tracer that is easily placed inside the casing sleeve. Before the casing sleeve is opened, the built-in solid chemical tracer remains sealed, not coming into contact with the injected fluid or formation fluid. After the casing sleeve is opened, as the fracturing fluid flows through the sleeve, the solid chemical tracer comes into contact with the fluid and is released, entering the reservoir directly with the fracturing fluid. This method avoids the problem of various types of tracers remaining in the horizontal section during conventional wellhead injection, where each tracer must flow through the entire horizontal wellbore, thus ensuring the accuracy of subsequent testing.

[0022] This invention can effectively solve the problems of complex chemical tracer testing and injection processes, numerous supporting equipment, high manpower and material resources, high costs, and low accuracy in existing chemical tracer testing. It truly realizes the integration of fracturing and production profile testing, significantly simplifies the operation process, improves operation efficiency and testing accuracy, and reduces overall costs. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of an embodiment of a horizontal well completion method that integrates segmented modification and production profile testing according to the present invention;

[0024] Figure 2 This is a schematic diagram of the sleeve sliding sleeve.

[0025] In the diagram, 1. Well casing; 2. Casing sleeve; 3. Solid chemical tracer; 4. Artificial fracture; 5. Upper connector; 6. Outer cylinder; 7. Ball seat; 8. Groove; 9. Inner cylinder; 10. Fluid flow channel; 11. Pin; 12. Lower connector. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings, but this is not intended to limit the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Example 1

[0028] like Figure 1 As shown, this invention provides a horizontal well completion method that integrates staged modification and production profile testing, comprising the following steps:

[0029] Step 1: The horizontal well is modified using staged fracturing technology. During the process of running the casing 1 after the horizontal well is drilled, multiple casing sleeves 2 are set at intervals on the casing and run into the horizontal well together with the casing 1. Each casing sleeve contains a solid chemical tracer 3. The types of solid chemical tracers 3 in each casing sleeve are different.

[0030] Step 2: During each fracturing stimulation of a horizontal well, a ball is dropped from the surface into the wellbore to open the casing sleeve 2. Then, fracturing fluid and proppant are injected. As the fracturing fluid flows through the casing sleeve 2, the solid chemical tracer 3 dissolves into the fracturing fluid and enters the reservoir along with the fracturing fluid.

[0031] Step 3: Repeat step 2 to complete the fracturing of all sections of the horizontal well, shut in the well, wait for the injected soluble balls to completely dissolve and restore the wellbore channel, and then open the well to enter flowback and production;

[0032] Step 4: Continuously collect produced fluid samples from different fracturing sections at the wellhead for analysis. Identify the types of solid chemical tracer 3 contained in each sample and quantify the proportion of each solid chemical tracer 3 to obtain the production profile of the entire horizontal well.

[0033] Furthermore, the number of casing sleeves is the same as the number of sections in the horizontal well fracturing, and each section in the horizontal well corresponds to one casing sleeve.

[0034] Furthermore, the types of solid chemical tracers in all the casing sleeves of the horizontal well are different, and the types of solid chemical tracers are the same as the number of fracturing sections of the horizontal well.

[0035] Furthermore, after all sections of the horizontal well have been fracturing, during the flowback and production processes, the solid chemical tracer from each section is brought to the surface along with the produced fluid after entering the wellbore. Preferably, the volume ratio of the fracturing fluid to the proppant is 5–7:1.

[0036] Furthermore, the solid chemical tracer is a halogenated aromatic compound. This is existing technology. The solid chemical tracer for each fracturing stage only needs to be of a different type.

[0037] Furthermore, the location of each fracturing section is obtained through well logging. Specifically, the oil content and physical properties of the entire horizontal section of the horizontal well are obtained through well logging, and the location with relatively good oil content and physical properties is selected as the fracturing section. A casing sleeve is deployed at the wellbore location corresponding to each fracturing section. The casing sleeve is connected in series with the wellbore casing inside the wellbore. Artificial fractures 4 can be formed in the fracturing section through fracturing.

[0038] Furthermore, such as Figure 2As shown, the sleeve includes: an upper connector 5, an outer cylinder 6, a ball seat 7, a groove 8, an inner cylinder 9, a liquid flow channel 10, a pin 11, and a lower connector 12; the upper and lower ends of the outer cylinder 6 are respectively provided with the upper connector 5 and the lower connector 12, the inner cylinder 9 is tightly attached to the inner cylinder 6, the upper end face of the inner cylinder 9 is provided with the ball seat 7, the lower end of the inner cylinder 9 is connected to the outer cylinder 6 by the pin 11, the inner wall of the outer cylinder 6 is provided with the groove 8, and the groove 8 is sealed by the cylinder wall at the upper end of the inner cylinder 9; a liquid flow channel 10 is provided on the wall of the outer cylinder 6 located near the lower connector 12, and the liquid flow channel 10 is sealed by the cylinder wall at the lower end of the inner cylinder 9, and a solid chemical tracer is provided in the groove 8.

[0039] The groove 8 described in this invention can be an annular groove, a single groove, or multiple grooves spaced apart, used to place the solid chemical tracer 3. Through the shielding of the inner cylinder 9 wall, this invention ensures that the solid chemical tracer 3 inside the sleeve 2 does not come into contact with the injected fluid and the formation fluid before the sleeve 2 is opened, and is in a sealed state.

[0040] The specific working process of the casing sliding sleeve of the present invention is as follows: After the ball is dropped in the initial stage of fracturing, the ball falls into the ball seat 7. Then, after pressure is applied, the pin 11 is sheared. After that, the ball pushes the ball seat 7 and the inner cylinder 9 to move down. Then, the built-in solid chemical tracer 3 is exposed. At the same time, the liquid flow channel 10 is opened. After the fracturing fluid passes through the solid chemical tracer 3, it enters the reservoir through the liquid flow channel 10.

[0041] It should be noted that the ball seat size of each stage of the casing sliding sleeve applied to horizontal wells is different. The ball seat size changes from small to large from the toe to the heel. The diameter of the ball thrown in each stage is different. Each stage of the casing sliding sleeve corresponds to a certain size of ball. Small balls are thrown in first from the toe to the heel, and then larger balls are thrown in stage by stage.

[0042] The innovation compared to existing technologies lies in the following: In conventional technologies, the tracer is added from the wellhead, flows through the entire wellbore, and then enters the reservoir through the perforation holes. While some well fracturing also utilizes casing sleeves, conventional casing sleeves only facilitate fluid flow and do not incorporate solid chemical tracers. This invention integrates the tracer into the casing sleeve, achieving a unified process for fracturing stimulation and tracer-based production profile testing. This simplifies the process, improves operational efficiency, and enhances testing accuracy by avoiding tracer residue in the wellbore.

[0043] Compared with the invention disclosed in CN113027430A, entitled "A Horizontal Well Production Profile Testing String and Process Based on Tracer Labeling", this invention integrates horizontal well segmentation and production profile testing into a single process, with a simple process flow and fewer supporting equipment.

[0044] Example 2

[0045] Unlike Example 1, this example is a manifestation of a horizontal well completion method integrating staged modification and production profile testing according to the present invention:

[0046] Step 1: The reservoir in a certain block is a low-permeability oil layer. It is transformed using horizontal well segmented fracturing technology. The horizontal section is 1000 meters long, and 12 sections are fracturing in a single well. 12 casing sleeves of the present invention are inserted into the casing of each horizontal well. Each casing sleeve contains a solid chemical tracer, and the type of solid chemical tracer in each casing sleeve is different.

[0047] Step 2: Equip one fracturing unit, 50 cubic meters of 20 / 40 mesh quartz sand proppant, and 300 cubic meters of fracturing fluid.

[0048] Step 3: During each fracturing stimulation of a horizontal well, a ball is dropped from the surface into the wellbore to open the casing sleeve. Then, fracturing fluid and proppant are injected. As the fracturing fluid flows through the casing sleeve, the solid chemical tracer comes into contact with the fluid and is released and dissolved into the fracturing fluid, entering the reservoir along with the fracturing fluid.

[0049] Step 4: Repeat step 3 to completely fracture all sections of the horizontal well. After shutting in the well for 10 days, the soluble balls will completely dissolve and restore the wellbore channel. Then, the well will be opened to enter the drainage and production stage.

[0050] Step 5: Surface technicians continuously collect produced fluid samples at the wellhead. Through laboratory analysis, they identify the types of solid chemical tracers contained in each sample and quantify the proportion of each solid chemical tracer. This tracer proportion can be considered as the proportion of the fluid produced in that section to the total fluid volume, i.e., the production contribution rate, thus obtaining the production profile of the entire horizontal well. Quantifying the proportion of each solid chemical tracer involves analyzing the produced fluid samples to determine the volume percentage of each tracer in the total volume.

[0051] Step 6: Based on the production profile, it was found that five sections of this horizontal well had a very small contribution rate to fluid production due to tight lithology, accounting for less than 20% of the total fluid volume. In future horizontal well fracturing design optimization in this block, the scale and intensity of stimulation for this type of tight reservoir need to be further increased.

[0052] This invention integrates fracturing and production profile testing. Compared with existing conventional horizontal well production profile testing methods (see Table 1), this invention improves testing accuracy by approximately 10%, increases operational efficiency by approximately 30%, and reduces costs by approximately 25%.

[0053] The existing conventional technology involves manually adding tracers from the surface into the wellbore using specialized equipment during the fracturing process.

[0054] Table 1: Comparison of the present invention with existing conventional technologies

[0055]

[0056] The method of this invention solves the problems of complex chemical tracer testing and injection processes, numerous supporting equipment, high manpower and material resources, high costs, and low accuracy in existing chemical tracer testing. It truly realizes the integration of fracturing and production profile testing, significantly simplifies the operation process, improves operation efficiency and testing accuracy, and reduces overall costs.

[0057] The above description is merely an illustrative embodiment of the present invention and is not intended to limit the scope of the invention. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principles of the present invention should fall within the scope of protection of the present invention. Components and structures not described in detail in this embodiment are well-known components, common structures, or common means in the industry and will not be described in detail here.

Claims

1. A horizontal well completion method integrating staged modification and production profile testing, characterized in that: Includes the following steps: Step 1: The horizontal well is modified using staged fracturing technology. During the casing running process after the horizontal well drilling is completed, multiple casing sleeves are spaced apart on the well casing and run into the horizontal well together with the well casing. Each casing sleeve contains a solid chemical tracer. The types of solid chemical tracers in each casing sleeve are different. Step 2: During each fracturing stimulation of a horizontal well, a ball is dropped from the surface into the wellbore to open the casing sleeve. Then, fracturing fluid and proppant are injected. As the fracturing fluid flows through the casing sleeve, the solid chemical tracer dissolves into the fracturing fluid and enters the reservoir along with the fracturing fluid. Step 3: Repeat step 2 to complete the fracturing of all sections of the horizontal well, shut in the well, wait for the injected soluble balls to completely dissolve and restore the wellbore channel, and then open the well to enter flowback and production; Step 4: Continuously collect produced fluid samples from different fracturing sections at the wellhead for analysis, identify the types of solid chemical tracers contained in each sample, and quantify the proportion of each solid chemical tracer to obtain the production profile of the entire horizontal well. The number of casing sleeves is the same as the number of sections in the horizontal well fracturing and modification, and each modified section in the horizontal well corresponds to one casing sleeve. The types of solid chemical tracers in all the casing sleeves of the horizontal well are different, and the types of solid chemical tracers are the same as the number of fracturing sections of the horizontal well. The sleeve includes: an upper connector, an outer cylinder, a ball seat, a groove, an inner cylinder, a fluid flow channel, a pin, and a lower connector; the upper and lower ends of the outer cylinder are respectively provided with an upper connector and a lower connector, the inner cylinder is tightly attached to the inner cylinder, the upper end face of the inner cylinder is provided with a ball seat, the lower end of the inner cylinder is connected to the outer cylinder by a pin, the inner wall of the outer cylinder is provided with a groove, and the groove is sealed by the upper end of the inner cylinder wall; a fluid flow channel is provided on the outer cylinder wall near the lower connector end, and the fluid flow channel is sealed by the lower end of the inner cylinder wall; a solid chemical tracer is provided in the groove; In the initial stage of fracturing, after the ball is dropped, it falls onto the ball seat. Then, after pressure is applied, the pin is sheared off. The ball then pushes the ball seat and inner cylinder downwards, exposing the built-in solid chemical tracer. At the same time, the fluid flow channel opens, and the fracturing fluid flows through the solid chemical tracer and enters the reservoir through the fluid flow channel.

2. The horizontal well completion method integrating segmented modification and production profile testing as described in claim 1, characterized in that: The volume ratio of the fracturing fluid to the proppant is 5 to 7:

1.

3. The horizontal well completion method integrating segmented modification and production profile testing as described in claim 1, characterized in that: Before the casing sleeve is opened, its built-in solid chemical tracer does not come into contact with the injected fluid or formation fluid and is in a sealed state.

4. The horizontal well completion method integrating segmented modification and production profile testing as described in claim 1, characterized in that: After all sections of the horizontal well have been fracturing, during the flowback and production processes, the solid chemical tracer of each section is brought to the surface along with the produced fluid after entering the wellbore.

5. The horizontal well completion method integrating segmented modification and production profile testing as described in claim 1, characterized in that: The solid chemical tracer is a halogenated aromatic compound.

6. The horizontal well completion method integrating segmented modification and production profile testing as described in claim 1, characterized in that: The location of each modified section was obtained by well logging.

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