Horizontal well injection-production integrated method

Abstract

In the field of oil and gas field development, a horizontal well injection-production integrated method is disclosed. This method includes determining the injection end and production end based on the main oil and gas enrichment areas in the reservoir or a comparison of injection and production volumes; forming an artificial seepage channel in the oil and gas reservoir between the injection end and production end of an inclined well section and / or horizontal well section; running tubing with an upper and lower packer into the casing of the inclined well section and / or horizontal well section where the artificial seepage channel has been formed; injecting a medium from the injection end; and extracting oil and gas from the reservoir from the production end. This invention utilizes the ultra-long distance of horizontal wells to establish seepage channels and applies injection-production integrated technology, enabling the large-scale extraction of oil and gas from horizontal wells and surrounding reservoirs, thus improving the reservoir recoverability coefficient; furthermore, by injecting gas and liquid, it increases formation pressure, prolonging the self-flowing time of oil and gas and improving economic efficiency.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas field development, and particularly relates to an integrated injection and production method for horizontal wells. Background Technology

[0002] The permeability of the overburden matrix in conventional oil and gas reservoirs is generally greater than 0.1 × 10⁻⁶. -3 μm 2 Oil and gas generally flow freely within reservoirs, and oil, gas, and water are clearly stratified under Earth's gravity. Conventional oil and gas reservoirs can serve as overall seepage channels. The permeability of the overburden matrix in unconventional oil and gas reservoirs is generally no greater than 0.1 × 10⁻⁶. -3 μm 2 Oil and gas generally have difficulty flowing within reservoirs, with indistinct oil, gas, and water stratification. Unconventional oil and gas reservoirs often lack clear seepage channels, and these channels are few and indistinct. Overburden matrix permeability refers to the formation permeability under specific conditions, such as the absence of fractures. Seepage channels are the pathways through which oil and gas can flow freely. Higher formation pressure provides greater impetus for oil and gas to flow from the formation into the wellbore, resulting in longer self-flowing times and higher economic benefits. If oil and gas cannot flow spontaneously or their flow weakens, pumping units are needed to extract them from the well, leading to lower production and lower efficiency. The formation pressure coefficient is less than 0.9 for low-pressure reservoirs, between 0.9 and 1.2 for atmospheric-pressure reservoirs, and greater than 1.2 for high-pressure reservoirs. The formation pressure coefficient is the ratio of formation pressure to hydrostatic pressure.

[0003] Unconventional oil and gas reservoirs are characterized by extremely low porosity and permeability, resulting in highly heterogeneous tight reservoirs. Furthermore, the development of unconventional oil and gas reservoirs requires artificial fractures, such as volumetric fracturing, to increase permeability for efficient production. However, the well control radius is relatively small, making it impossible to utilize pressure drop funnels for multi-well injection-production development. Currently, injection-production enhancement measures are mainly applied to conventional or fractured oil and gas reservoirs. Conventional reservoirs have higher porosity and permeability, allowing the injection of gaseous or liquid substances such as carbon dioxide, nitrogen, natural gas, and water into one or more wells to create a relatively high-pressure reservoir area. This drives the remaining oil and gas to flow into a low-pressure area, where oil and gas can be extracted in another well or several surrounding wells in an adjacent low-pressure area. These extraction wells are typically vertical wells and are primarily used for secondary oil recovery.

[0004] Unconventional oil and gas reservoirs are highly heterogeneous and have small well control radii, especially in low-pressure or normal-pressure oil and gas reservoir areas. It is difficult to achieve industrial production capacity, resulting in low cumulative production, large remaining oil and gas reserves, low recovery rates, and a lack of secondary oil recovery measures.

[0005] Therefore, it is necessary to provide a horizontal well injection-production integrated technology to implement injection and production enhancement measures in unconventional oil and gas reservoirs. Summary of the Invention

[0006] To overcome the shortcomings of the existing technology, the present invention aims to provide an integrated injection and production method for horizontal wells. By utilizing the ultra-long distance of the horizontal well, a seepage channel is artificially established to extract as much oil and gas as possible from the horizontal well and surrounding oil and gas reservoirs, thereby reducing the amount of remaining or difficult-to-recover oil and gas in the reservoirs, increasing the recoverability coefficient of the oil and gas reservoirs, and increasing formation pressure by injecting gas or liquid, extending the self-flowing time of oil and gas, and improving economic benefits.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A horizontal well injection and production integrated method includes:

[0009] The injection end and production end are determined by comparing the main oil and gas enrichment areas in the oil and gas reservoir or the injection volume with the production volume.

[0010] Artificial seepage channels are formed in oil and gas reservoirs between the injection end and the production end of the inclined and / or horizontal well sections that pass through the reservoir.

[0011] Run tubing with an upper packer and a lower packer into the tubing of the inclined well section and / or horizontal well section where artificial seepage channels have been formed;

[0012] The medium is injected from the injection end, and the oil and gas in the reservoir are extracted from the extraction end.

[0013] Furthermore, based on the main oil and gas enrichment areas in the reservoir or the comparison between injection and production volumes, the injection and production ends are determined, including:

[0014] When the injection volume of oil and gas reservoir is less than the production volume, or when oil and gas are mainly concentrated in the deviated section and / or the front end of the horizontal well, the tail end of the deviated section and / or the horizontal well is used as the injection end, and the front end of the deviated section and / or the horizontal well is used as the production end, and oil and gas are extracted from the annulus of the casing and tubing at the front end of the deviated section and / or the horizontal well.

[0015] When the injected oil and gas reservoir volume is greater than the produced volume, or when the oil and gas are mainly concentrated at the tail end of the inclined section and / or horizontal section, the front end of the inclined section and / or horizontal section is used as the injection end, and injection is carried out through the annulus of the casing at the front end of the inclined section and / or horizontal section. The tail end of the inclined section and / or horizontal section is used as the production end.

[0016] Furthermore, artificial seepage channels are formed in the oil and gas reservoir between the injection end and the production end of the deviated and / or horizontal well sections, including:

[0017] Artificial seepage channels are created in oil and gas reservoirs in deviated and / or horizontal sections through perforation and staged sand fracturing operations.

[0018] Furthermore, artificial seepage channels are formed in the oil and gas reservoir between the injection end and the production end of the deviated and / or horizontal well sections that traverse the reservoir, including:

[0019] Perforation and segmented sand fracturing operations are carried out from the injection end to the mining end.

[0020] Furthermore, artificial seepage channels are formed in the oil and gas reservoir between the injection end and the production end of the deviated and / or horizontal well sections that traverse the reservoir, including:

[0021] Perforation and segmented sand fracturing operations are carried out towards the oil and gas reservoir around the wellbore at the production end.

[0022] Furthermore, artificial seepage channels are formed in the oil and gas reservoir between the injection end and the production end of the deviated and / or horizontal well sections that traverse the reservoir, including:

[0023] Perforation and segmented sand fracturing operations were carried out around the wellbore in the direction of the oil and gas reservoir between the upper and lower packers.

[0024] Furthermore, artificial seepage channels are formed in the oil and gas reservoir between the injection end and the production end of the deviated and / or horizontal well sections that traverse the reservoir, including:

[0025] The perforation and segmented sand fracturing construction direction and personnel flow channels are designed according to the wellbore trajectory of different horizontal and inclined well sections.

[0026] Furthermore, wellbore trajectories include flume-shaped trajectories, horizontal trajectories, and wave-shaped trajectories.

[0027] Furthermore, horizontal well injection and production includes single-well horizontal well injection and production and multi-well horizontal well injection and production;

[0028] When performing injection and production in horizontal wells across multiple wells, the injection wells and production wells are determined based on the main oil and gas enrichment areas in the oil and gas reservoir or the comparison between the injection volume and the production volume.

[0029] Artificial seepage channels are formed in the oil and gas reservoir between the injection well and the production well through perforation and fracturing operations;

[0030] Injecting medium from injection wells and extracting oil and gas from production wells.

[0031] Furthermore, multiple wells include multiple horizontal wells and zero to multiple vertical wells.

[0032] The technical effects and advantages of this invention are as follows:

[0033] This invention utilizes the ultra-long distance of horizontal wells to artificially create seepage channels and applies integrated injection and production technology to extract large quantities of oil and gas from horizontal wells and surrounding oil and gas reservoirs, reduce the amount of remaining or difficult-to-recover oil and gas in the reservoirs, and improve the recoverability coefficient of the oil and gas reservoirs; moreover, by injecting gas and liquid to increase formation pressure, the self-flowing time of oil and gas can be extended, thereby improving economic benefits.

[0034] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description, claims and drawings. Attached Figure Description

[0035] Figure 1 This is a flowchart of an integrated injection and production method for horizontal wells according to the present invention;

[0036] Figure 2 This is a schematic diagram of perforation construction using a water-trough-shaped wellbore trajectory according to the present invention.

[0037] Figure 3 This is a schematic diagram of fracturing construction where the wellbore trajectory is a water-trough type according to the present invention;

[0038] Figure 4 This is a schematic diagram of the oil and gas enrichment area in an oil and gas reservoir with a wellbore trajectory of a water trough-shaped trajectory according to the present invention.

[0039] Figure 5 This is a schematic diagram of the tail injection pre-production construction of the wellbore trajectory with a water-trough-shaped trajectory according to the present invention;

[0040] Figure 6 This is a schematic diagram of perforation construction with a horizontal wellbore trajectory according to the present invention;

[0041] Figure 7 This is a schematic diagram of fracturing operation using a horizontal wellbore trajectory according to the present invention.

[0042] Figure 8 This is a schematic diagram of an oil and gas enrichment region in an oil and gas reservoir with a horizontal wellbore trajectory, as described in this invention.

[0043] Figure 9 This is a schematic diagram of the tail injection pre-production construction of the wellbore trajectory of the present invention, which is a horizontal trajectory.

[0044] Figure 10 This is a schematic diagram of perforation construction with a wave-shaped wellbore trajectory according to the present invention.

[0045] Figure 11 This is a schematic diagram of fracturing operation with a wave-shaped wellbore trajectory according to the present invention.

[0046] Figure 12This is a schematic diagram of an oil and gas enrichment area in an oil and gas reservoir where the wellbore trajectory is a wave-shaped trajectory, according to the present invention.

[0047] Figure 13 This is a schematic diagram of the tail injection pre-production construction of the wellbore trajectory with a wave-shaped trajectory according to the present invention;

[0048] Figure 14 This is a schematic diagram of the injection and production construction of multiple horizontal wells in combination with vertical wells according to the present invention, including horizontal, flume and wave types.

[0049] Figure 15 This is a schematic diagram of the injection and production construction of multi-well horizontal wells using a combination of several horizontal well trajectories (including horizontal type, water channel type and wave type) according to the present invention. Detailed Implementation

[0050] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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.

[0051] like Figure 1 As shown, the present invention provides an integrated injection and production method for horizontal wells, comprising:

[0052] Based on the main oil and gas enrichment areas in the oil and gas reservoir, or the comparison between the injection volume and the production volume, or the technological measures to solve sand and wax deposition, the injection end and the production end are determined.

[0053] Artificial seepage channels are formed in oil and gas reservoirs between the injection end and the production end of the inclined and / or horizontal well sections that pass through the reservoir.

[0054] Run tubing with an upper packer and a lower packer into the tubing of the inclined well section and / or horizontal well section where artificial seepage channels have been formed;

[0055] The medium is injected from the injection end, and the oil and gas in the reservoir is extracted from the production end. The medium enters the oil and gas reservoir near the injection end and is driven to move towards the production end through the artificial seepage channel formed in the oil and gas reservoir between the injection end and the production end, where it is extracted.

[0056] It should be noted that the casing is a cylindrical pipeline whose main function is to prevent formation collapse and can also be used to extract oil and gas from the formation to the wellhead. The tubing is also a cylindrical pipeline, but its diameter is smaller than that of the casing. The tubing is generally located inside the casing, so the inside of the tubing is a gas-liquid flow channel, and the annulus between the tubing and the casing is another gas-liquid flow channel. The packer closer to the wellhead is the upper packer, and the packer closer to the bottom of the well is the lower packer. The section of the oil and gas reservoir between the upper packer and the wellhead is the front end, and the section of the oil and gas reservoir between the lower packer and the bottom of the well is the back end.

[0057] In some embodiments of the present invention, the injection end and the production end are determined based on the main oil and gas enrichment areas in the oil and gas reservoir or a comparison between the injection volume and the production volume, including:

[0058] When the injection rate of an oil and gas reservoir is less than the production rate, or when the oil and gas are mainly concentrated in the deviated section and / or the front end of a horizontal well, the tail end of the deviated section and / or the horizontal well is used as the injection end, and the front end of the deviated section and / or the horizontal well is used as the production end. Under the action of high pressure and the lower packer, the medium enters the oil and gas reservoir near the tail end of the deviated section and / or the horizontal well. Through the artificial seepage channel in the oil and gas reservoir, the oil and gas in the oil and gas reservoir near the tail end of the deviated section and / or the horizontal well is driven to move towards the front end of the deviated section and / or the horizontal well. Under the action of the upper packer, the oil and gas are extracted from the annulus of the casing at the front end of the deviated section and / or the horizontal well.

[0059] When the injected oil and gas reservoir volume exceeds the extracted volume, or when the oil and gas are mainly concentrated at the tail end of the inclined and / or horizontal well sections, the front end of the inclined and / or horizontal well sections is used as the injection end, and the tail end of the inclined and / or horizontal well sections is used as the extraction end. Injection is carried out through the annulus of the casing at the front end of the inclined and / or horizontal well sections. Under the action of high pressure and the upper packer, the medium enters the oil and gas reservoir near the front end of the inclined and / or horizontal well sections. Through the artificial seepage channels in the oil and gas reservoir, the oil and gas in the reservoir near the front end of the inclined and / or horizontal well sections are driven to migrate towards the tail end of the inclined and / or horizontal well sections. Under the action of the lower packer, the oil and gas are extracted from the tubing at the tail end of the inclined and / or horizontal well sections.

[0060] In some embodiments of the present invention, an artificial seepage channel is formed in the oil and gas reservoir between the injection end and the production end of an inclined well section and / or a horizontal well section passing through the reservoir, including:

[0061] Artificial seepage channels are created in oil and gas reservoirs in deviated and / or horizontal sections through perforation and staged sand fracturing operations.

[0062] In some embodiments of the present invention, an artificial seepage channel is formed in the oil and gas reservoir between the injection end and the production end of an inclined well section and / or a horizontal well section passing through the reservoir, including:

[0063] Perforation and segmented sand fracturing operations are carried out from the injection end to the mining end.

[0064] In some embodiments of the present invention, an artificial seepage channel is formed in the oil and gas reservoir between the injection end and the production end of an inclined well section and / or a horizontal well section passing through the reservoir, including:

[0065] Perforation and segmented sand fracturing operations are carried out towards the oil and gas reservoir around the wellbore at the production end.

[0066] In some embodiments of the present invention, an artificial seepage channel is formed in the oil and gas reservoir between the injection end and the production end of an inclined well section and / or a horizontal well section passing through the reservoir, including:

[0067] Perforation and segmented sand fracturing operations were carried out around the wellbore in the direction of the oil and gas reservoir between the upper and lower packers.

[0068] In some embodiments of the present invention, an artificial seepage channel is formed in the oil and gas reservoir between the injection end and the production end of an inclined well section and / or a horizontal well section passing through the reservoir, including:

[0069] The perforation and segmented sand fracturing construction direction and personnel flow channels are designed according to the wellbore trajectory of different horizontal and inclined well sections.

[0070] In some embodiments of the present invention, the wellbore trajectory includes a flume-shaped trajectory, a horizontal trajectory, and a wave trajectory.

[0071] In some embodiments of the present invention, horizontal well injection and production includes single-well horizontal well injection and production and multi-well horizontal well injection and production.

[0072] When performing injection and production in horizontal wells across multiple wells, the injection wells and production wells are determined based on the main oil and gas enrichment areas in the oil and gas reservoir or the comparison between the injection volume and the production volume.

[0073] Artificial seepage channels are formed in the oil and gas reservoir between the injection well and the production well through perforation and fracturing operations;

[0074] Injecting medium from injection wells and extracting oil and gas from production wells.

[0075] In some embodiments of the present invention, multiple wells include multiple horizontal wells and zero to multiple vertical wells.

[0076] To better illustrate this solution, the following embodiments are also provided.

[0077] Example 1

[0078] The injection-production integrated method in this embodiment adopts the tail injection-before-production approach to carry out integrated injection-production construction on inclined well sections and horizontal well sections with a wellbore trajectory of a water trough shape.

[0079] S1. Determine the injection end and production end based on the main oil and gas enrichment areas in the oil and gas reservoir or the comparison between the injection volume and the production volume.

[0080] When the injection volume of oil and gas reservoir is less than the production volume, or when oil and gas are mainly concentrated in the deviated section and / or the front end of the horizontal well, the tail end of the deviated section and / or the horizontal well is used as the injection end, and the front end of the deviated section and / or the horizontal well is used as the production end, and oil and gas are extracted from the annulus of the casing and tubing at the front end of the deviated section and / or the horizontal well.

[0081] When the injected oil and gas reservoir volume is greater than the produced volume, or when the oil and gas are mainly concentrated at the tail end of the inclined section and / or horizontal section, the front end of the inclined section and / or horizontal section is used as the injection end, and injection is carried out through the annulus of the casing at the front end of the inclined section and / or horizontal section. The tail end of the inclined section and / or horizontal section is used as the production end.

[0082] S2, such as Figure 1 As shown, in the inclined sections 602 and 604, perforations penetrate into the soft formation, while in the horizontal section 603, a perforation penetrates the hard formation and enters the soft formation; as... Figure 2 As shown, in combination with the construction conditions, a segmented sand fracturing construction process is adopted to divide the wellbore into several segments. Each segment is subjected to sand fracturing to form a complex fracture network. The well is then connected and extended to form a fracture network channel.

[0083] S3, such as Figure 3 As shown, tubing with upper and lower packers is lowered into the wellbore. The wellhead tubing is closed, and the wellbore and tubing annulus are open. Because the upper and lower packers isolate the tubing from the wellbore annulus, oil and gas and fracturing fluid in the soft formation can only enter the tubing and wellbore annulus at the front end of the wellbore through the complex fracture network, eventually flowing to the surface and forming a relatively low-pressure zone at the front end of the wellbore.

[0084] S4, such as Figure 4 As shown, when the pressure of the oil and gas reservoir is low, the oil and gas cannot flow to the surface and need to be injected for oil production. The injected fluid flows through the tubing in the wellbore to the tail end of the wellbore. Due to the action of the packer, the injected fluid can only enter the oil and gas-bearing soft formation (such as shale oil layer) through the complex fracture network at the tail end of the wellbore. Because the pressure at the front end of the wellbore is low, the injected fluid pushes the oil and gas in the soft formation to flow towards the front end of the wellbore and enter the wellbore, eventually flowing to the surface.

[0085] Example 2

[0086] The injection-production integrated method in this embodiment adopts the tail injection-before-production approach to carry out integrated injection-production construction on inclined well sections and horizontal well sections with horizontal well trajectories.

[0087] S1. Determine the injection end and production end based on the main oil and gas enrichment areas in the oil and gas reservoir or the comparison between the injection volume and the production volume.

[0088] When the injection volume of oil and gas reservoir is less than the production volume, or when oil and gas are mainly concentrated in the deviated section and / or the front end of the horizontal well, the tail end of the deviated section and / or the horizontal well is used as the injection end, and the front end of the deviated section and / or the horizontal well is used as the production end, and oil and gas are extracted from the annulus of the casing and tubing at the front end of the deviated section and / or the horizontal well.

[0089] When the injected oil and gas reservoir volume is greater than the produced volume, or when the oil and gas are mainly concentrated at the tail end of the inclined section and / or horizontal section, the front end of the inclined section and / or horizontal section is used as the injection end, and injection is carried out through the annulus of the casing at the front end of the inclined section and / or horizontal section. The tail end of the inclined section and / or horizontal section is used as the production end.

[0090] S2, such as Figure 5 As shown, in the inclined section 702, perforations penetrate into the soft formation, while in the horizontal section 703, perforations penetrate the hard formation and enter the soft formation. (See diagram.) Figure 6 As shown, based on the construction conditions, a segmented sand fracturing construction process can be adopted, dividing the wellbore into several segments, each segment undergoing sand fracturing to form a complex fracture network, which is then connected and extended to form fracture network channels.

[0091] S3, such as Figure 7 As shown, tubing with upper and lower packers is lowered into the wellbore. The wellhead tubing is closed, and the wellbore and tubing annulus are open. Because the upper and lower packers isolate the tubing from the wellbore annulus, oil and gas and fracturing fluid in the soft formation can only enter the tubing and wellbore annulus at the front end of the wellbore through the complex fracture network, eventually flowing to the surface and forming a relatively low-pressure zone at the front end of the wellbore.

[0092] S4, such as Figure 8 As shown, when the pressure of the oil and gas reservoir is low, the oil and gas cannot flow to the surface and need to be injected for oil production. The injected fluid flows through the tubing in the wellbore to the tail end of the wellbore. Due to the action of the packer, the injected fluid can only enter the oil and gas-bearing soft formation (such as shale oil layer) through the complex fracture network at the tail end of the wellbore. Because the pressure at the front end of the wellbore is low, the injected fluid pushes the oil and gas in the soft formation to flow towards the front end of the wellbore and enter the wellbore, eventually flowing to the surface.

[0093] Example 3

[0094] The injection-production integrated method in this embodiment adopts the tail injection-before-production approach to carry out injection-production integrated construction on the inclined well section with a wave-shaped well trajectory.

[0095] S1. Determine the injection end and production end based on the main oil and gas enrichment areas in the oil and gas reservoir or the comparison between the injection volume and the production volume.

[0096] When the injection volume of oil and gas reservoir is less than the production volume, or when oil and gas are mainly concentrated in the deviated section and / or the front end of the horizontal well, the tail end of the deviated section and / or the horizontal well is used as the injection end, and the front end of the deviated section and / or the horizontal well is used as the production end, and oil and gas are extracted from the annulus of the casing and tubing at the front end of the deviated section and / or the horizontal well.

[0097] When the injected oil and gas reservoir volume is greater than the produced volume, or when the oil and gas are mainly concentrated at the tail end of the inclined section and / or horizontal section, the front end of the inclined section and / or horizontal section is used as the injection end, and injection is carried out through the annulus of the casing at the front end of the inclined section and / or horizontal section. The tail end of the inclined section and / or horizontal section is used as the production end.

[0098] S2, such as Figure 9 As shown, perforations were made in inclined sections 802 and 803 into the soft formation. Figure 10 As shown, based on the construction conditions, a segmented sand fracturing construction process can be adopted, dividing the wellbore into several segments, each segment undergoing sand fracturing to form a complex fracture network, which is then connected and extended to form fracture network channels.

[0099] S3, such as Figure 11 As shown, tubing with upper and lower packers is lowered into the wellbore. The wellhead tubing is closed, and the wellbore and tubing annulus are open. Because the upper and lower packers isolate the tubing from the wellbore annulus, oil and gas and fracturing fluid in the soft formation can only enter the tubing and wellbore annulus at the front end of the wellbore through the complex fracture network, eventually flowing to the surface and forming a relatively low-pressure zone at the front end of the wellbore.

[0100] S4, such as Figure 12 As shown, when the pressure of the oil and gas reservoir is low, the oil and gas cannot flow to the surface and need to be injected for oil production. The injected fluid flows through the tubing in the wellbore to the tail end of the wellbore. Due to the action of the packer, the injected fluid can only enter the oil and gas-bearing soft formation (such as shale oil layer) through the complex fracture network at the tail end of the wellbore. Because the pressure at the front end of the wellbore is low, the injected fluid pushes the oil and gas in the soft formation to flow towards the front end of the wellbore and enter the wellbore, eventually flowing to the surface.

[0101] Example 4

[0102] The injection-production integrated method in this embodiment uses horizontal well groups as injection wells and vertical well groups as production wells to carry out integrated injection-production construction of horizontal well groups and vertical well combinations.

[0103] like Figure 13 As shown, the spacing and number of horizontal and vertical well groups are designed based on the distribution of oil and gas reservoir enrichment, fracture development degree, and fracturing width, according to... Figures 1-12 As shown, based on the construction conditions, a segmented sand fracturing construction process can be adopted to fracture horizontal and vertical well groups with sand, forming a complex fracture network. The complex fracture network can be connected and extended to form inter-well fracture network channels.

[0104] When the formation pressure is high, both horizontal and vertical well groups can be used as production wells to extract oil and gas from the reservoir.

[0105] When formation pressure is low, oil and gas cannot flow to the surface or the production to the surface is low, requiring fluid injection for oil recovery. Based on the location of oil and gas accumulation, horizontal and vertical well groups are determined as injection or production wells. Depending on the injection end location, packers can be installed, and fluid is injected into the injection well. Due to high pressure, the injected fluid enters the complex fracture network of the oil and gas reservoir and propels the oil and gas into the production wellbore, eventually flowing to the surface.

[0106] Example 5

[0107] This embodiment, based on embodiment 4, changes the vertical well group into another set of horizontal wells, resulting in two sets of horizontal wells, such as... Figure 14 As shown, one set of horizontal wells is the injection well group, and the other set of horizontal wells is the production well group.

[0108] In summary, this invention utilizes the ultra-long distance of horizontal wells to artificially create seepage channels and applies integrated injection and production technology to extract large quantities of oil and gas from horizontal wells and surrounding oil and gas reservoirs, reduce the amount of remaining or difficult-to-recover oil and gas in the reservoirs, and improve the recoverability coefficient of the oil and gas reservoirs. Furthermore, by injecting gas and liquid to increase formation pressure, the self-flowing time of oil and gas can be extended, thereby improving economic benefits.

[0109] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A horizontal well injection and production integrated method, characterized in that, include: Based on the main oil and gas enrichment areas in the oil and gas reservoir or the comparison between the injection volume and the production volume, the injection end and the production end are determined. When the oil and gas reservoir injection volume is less than the production volume or the oil and gas are mainly enriched in the inclined section and / or the front end of the horizontal well, the tail end of the inclined section and / or the horizontal well is taken as the injection end, and the front end of the inclined section and / or the horizontal well is taken as the production end. Oil and gas are extracted from the annulus of the casing and tubing at the front end of the inclined section and / or the horizontal well. When the oil and gas reservoir injection volume is greater than the production volume or the oil and gas are mainly enriched in the tail end of the inclined section and / or the horizontal well, the front end of the inclined section and / or the horizontal well is taken as the injection end. Injection is carried out through the annulus of the casing and tubing at the front end of the inclined section and / or the horizontal well, and the tail end of the inclined section and / or the horizontal well is taken as the production end. Artificial seepage channels are formed in oil and gas reservoirs between the injection end and the production end of the inclined and / or horizontal well sections that pass through the reservoir. Run tubing with an upper packer and a lower packer into the casing of the inclined well section and / or horizontal well section where an artificial seepage channel has been formed; When the medium is injected from the injection end and the oil and gas reservoir is extracted from the production end, and the front end of the inclined section and / or horizontal section is used as the production end, the oil and gas and fracturing fluid can only enter the tubing and wellbore annulus at the front end of the wellbore through the complex fracture network, and eventually flow to the surface, forming a relatively low-pressure area at the front end of the wellbore. The injected medium can only enter the oil and gas-bearing soft formation through the complex fracture network at the tail end of the wellbore.

2. The horizontal well injection and production integrated method according to claim 1, characterized in that, The aforementioned creation of artificial seepage channels in the oil and gas reservoir between the injection end and the production end of the deviated and / or horizontal well sections passing through the reservoir includes: Artificial seepage channels are created in oil and gas reservoirs in deviated and / or horizontal sections through perforation and staged sand fracturing operations.

3. The horizontal well injection and production integrated method according to claim 2, characterized in that, The aforementioned creation of artificial seepage channels in the oil and gas reservoir between the injection end and the production end of the deviated and / or horizontal well sections passing through the reservoir includes: Perforation and segmented sand fracturing operations are carried out from the injection end to the mining end.

4. The horizontal well injection and production integrated method according to claim 2, characterized in that, The aforementioned creation of artificial seepage channels in the oil and gas reservoir between the injection end and the production end of the deviated and / or horizontal well sections passing through the reservoir includes: Perforation and segmented sand fracturing operations are carried out towards the oil and gas reservoir around the wellbore at the production end.

5. The horizontal well injection and production integrated method according to claim 2, characterized in that, The aforementioned creation of artificial seepage channels in the oil and gas reservoir between the injection end and the production end of the deviated and / or horizontal well sections passing through the reservoir includes: Perforation and segmented sand fracturing operations were carried out around the wellbore in the direction of the oil and gas reservoir between the upper and lower packers.

6. The horizontal well injection and production integrated method according to claim 2, characterized in that, The aforementioned creation of artificial seepage channels in the oil and gas reservoir between the injection end and the production end of the deviated and / or horizontal well sections passing through the reservoir includes: The perforation and segmented sand fracturing construction direction and personnel flow channels are designed according to the wellbore trajectory of different horizontal and inclined well sections.

7. The horizontal well injection and production integrated method according to claim 6, characterized in that, The wellbore trajectory includes a flume-shaped trajectory, a horizontal trajectory, and a wave-shaped trajectory.

8. The horizontal well injection and production integrated method according to claim 1, characterized in that, The horizontal well injection and production includes single-well horizontal well injection and production and multi-well horizontal well injection and production. When performing injection and production in horizontal wells across multiple wells, the injection wells and production wells are determined based on the main oil and gas enrichment areas in the oil and gas reservoir or the comparison between the injection volume and the production volume. Artificial seepage channels are formed in the oil and gas reservoir between the injection well and the production well through perforation and fracturing operations. Injecting medium from injection wells and extracting oil and gas from production wells.

9. The horizontal well injection and production integrated method according to claim 8, characterized in that, The multiple wells include multiple horizontal wells and zero to multiple vertical wells.

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