Injection-production integrated method for horizontal well

Abstract

The invention relates to the field of oil-gas field development, and discloses a horizontal well injection-production integrated method which comprises the following steps: determining an injection end and a production end according to a main oil-gas enrichment area in an oil-gas reservoir or the comparison between the injection amount and the production amount; an artificial seepage channel is formed in the oil and gas reservoir between the injection end and the exploitation end of the inclined shaft section and / or the horizontal well section penetrating through the oil and gas reservoir; an oil pipe with an upper packer and a lower packer is arranged in the oil casing of the inclined shaft section and / or the horizontal well section where the artificial seepage channel is formed; injecting a medium from the injection end, and exploiting oil and gas of the oil-gas reservoir from the exploiting end. By utilizing the ultra-long distance of the horizontal well, establishing a seepage channel and applying an injection-production integrated technology, a large amount of oil and gas in the horizontal well and surrounding oil and gas reservoirs can be exploited, and the exploitable coefficient of the oil and gas reservoirs is improved; and by injecting gas and liquid, the formation pressure is improved, the oil and gas self-spraying time can be prolonged, and the economic benefits are improved.

Description

Technical Field

[0001] The invention belongs to the field of oil and gas field development, and in particular relates to a horizontal well injection-production integrated method. Background Art

[0002] The matrix permeability of conventional oil and gas reservoirs is generally greater than 0.1×10 -3 μm 2 , oil and gas can generally flow freely in the reservoir, oil, gas and water are clearly stratified under the gravity of the earth, and conventional oil and gas reservoirs can be used as integral seepage channels. The reservoir matrix permeability of unconventional oil and gas reservoirs is generally not more than 0.1×10 -3 μm 2 , oil and gas are generally difficult to flow in the reservoir, the oil, gas and water stratification is not obvious, the seepage channels of unconventional oil and gas reservoirs are not obvious, and there are few seepage channels. Among them, the overburden matrix permeability is the formation permeability under special conditions such as no cracks in the formation state; the seepage channel is the channel through which oil and gas can flow freely. The higher the formation pressure, the greater the power to push oil and gas from the formation into the wellbore, the longer the oil and gas self-flow time, and the higher the economic benefit. If the oil and gas cannot flow or the self-flow is weakened, it is necessary to use a pumping unit to extract the oil and gas from the well. The oil and gas production is small and the efficiency is poor. The low-pressure formation pressure coefficient is less than 0.9, the normal pressure formation pressure coefficient is between 0.9 and 1.2, and the high-pressure formation pressure coefficient is greater than 1.2. The formation pressure coefficient is the ratio of the formation pressure to the hydrostatic column pressure;

[0003] Unconventional oil and gas reservoirs have extremely low porosity and permeability, and their tight reservoirs are highly heterogeneous. In addition, the exploitation of unconventional oil and gas reservoirs requires volume fracturing and other artificial fractures to increase permeability for efficient exploitation. However, the well control radius is small, and it is impossible to use a pressure drop funnel to achieve multi-well injection and production development. At present, injection and production and other production-increasing measures are mainly used in conventional oil and gas reservoirs or fractured oil and gas reservoirs. Because conventional oil and gas reservoirs have high porosity and permeability, carbon dioxide, nitrogen, natural gas, water and other gas liquids can be injected into the oil and gas reservoir in one or more wells to form a relatively high-pressure oil and gas reservoir area, driving the remaining oil and gas to flow to the low-pressure area, and then producing oil and gas in another well or multiple wells in the adjacent low-pressure area. The wells for producing oil and gas are generally vertical wells, which are mostly used for secondary oil recovery.

[0004] Unconventional oil and gas reservoirs are difficult to reach industrial production capacity due to their strong heterogeneity and small well control radius, especially in low-pressure or normal-pressure oil and gas reservoir areas. They have low cumulative production, large remaining oil and gas volumes, low recovery rates, and rarely take secondary oil recovery measures.

[0005] Therefore, it is necessary to provide an integrated injection-production technology for horizontal wells to implement injection-production and other production-enhancing measures in unconventional oil and gas reservoirs. Summary of the invention

[0006] In order to overcome the defects of the above-mentioned prior art, the purpose of the present invention is to provide an integrated injection and production method for horizontal wells, which utilizes the ultra-long distance of the horizontal well to artificially establish a seepage channel, and exploits the oil and gas in the horizontal well and the surrounding oil and gas reservoirs as much as possible, reduces the storage volume of residual oil and gas or difficult-to-recover oil and gas in the oil and gas reservoirs, improves the recoverable coefficient of the oil and gas reservoirs, increases the formation pressure by injecting gas or liquid, prolongs the oil and gas self-flowing time, and improves the economic benefits.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A horizontal well injection-production integrated method, comprising:

[0009] Determine the injection end and production end based on the main oil and gas enrichment area in the oil and gas reservoir or the comparison between the injection volume and the production volume;

[0010] forming an artificial seepage channel in the oil and gas reservoir between the injection end and the production end of the inclined well section and / or the horizontal well section passing through the oil and gas reservoir;

[0011] An oil pipe with an upper packer and a lower packer is run into the oil casing in the inclined well section and / or the horizontal well section where an artificial seepage channel has been formed;

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

[0013] Furthermore, the injection end and the production end are determined according to the comparison between the main oil and gas enrichment areas in the oil and gas reservoir or the injection volume and the production volume, including:

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

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

[0016] Furthermore, an artificial seepage channel is formed in the oil and gas reservoir between the injection end and the production end of the inclined well section and / or the horizontal well section of the oil and gas reservoir, comprising:

[0017] Artificial seepage channels are formed in the oil and gas reservoirs in the inclined well section and / or horizontal well section through perforation and staged sand fracturing construction.

[0018] Furthermore, an artificial seepage channel is formed in the oil and gas reservoir between the injection end and the production end of the inclined well section and / or the horizontal well section passing through the oil and gas reservoir, comprising:

[0019] Perforation and staged sand fracturing are carried out from the injection end to the production end.

[0020] Furthermore, an artificial seepage channel is formed in the oil and gas reservoir between the injection end and the production end of the inclined well section and / or the horizontal well section passing through the oil and gas reservoir, comprising:

[0021] Perforation and staged sand fracturing are carried out in the direction of the oil and gas reservoirs around the wellbore at the production end.

[0022] Furthermore, an artificial seepage channel is formed in the oil and gas reservoir between the injection end and the production end of the inclined well section and / or the horizontal well section passing through the oil and gas reservoir, comprising:

[0023] Perforation and staged sand fracturing are carried out in the direction of the oil and gas reservoir around the wellbore between the upper packer and the lower packer.

[0024] Furthermore, an artificial seepage channel is formed in the oil and gas reservoir between the injection end and the production end of the inclined well section and / or the horizontal well section passing through the oil and gas reservoir, comprising:

[0025] The perforation and staged sand fracturing construction directions and human flow channels are designed according to the wellbore trajectories of different horizontal and inclined sections.

[0026] Furthermore, the wellbore trajectory includes a flume-type trajectory, a horizontal trajectory and a wave trajectory.

[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 injecting and producing horizontal wells between 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] Through perforation and fracturing operations, artificial seepage channels are formed in the oil and gas reservoir between the injection well and the production well;

[0030] The medium is injected from the injection well, and the oil and gas in the oil and gas reservoir are produced from the production well.

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

[0032] Technical effects and advantages of the present invention:

[0033] The present invention utilizes the ultra-long distance of the horizontal well to artificially establish a seepage channel, and applies the injection-production integrated technology, so as to exploit a large amount of oil and gas in the horizontal well and the surrounding oil and gas reservoirs, reduce the storage volume of the remaining oil and gas or the difficult-to-recover oil and gas in the oil and gas reservoirs, and improve the recoverable coefficient of the oil and gas reservoirs; and by injecting gas liquid to increase the formation pressure, the oil and gas self-flowing time can be extended, and the economic benefits can be improved.

[0034] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A flow chart of a horizontal well injection-production integrated method of the present invention;

[0036] Figure 2 It is a schematic diagram of perforation construction in which the wellbore trajectory of the present invention is a water trough-type trajectory;

[0037] Figure 3 It is a schematic diagram of the fracturing construction of the present invention in which the wellbore trajectory is a water tank-type trajectory;

[0038] Figure 4 A schematic diagram of an oil and gas enrichment area in an oil and gas reservoir in which the wellbore trajectory of the present invention is a water trough-type trajectory;

[0039] Figure 5 It is a schematic diagram of the tail injection front mining construction in which the wellbore trajectory of the present invention is a water tank type trajectory;

[0040] Figure 6 It is a schematic diagram of perforation construction in which the wellbore trajectory of the present invention is a horizontal trajectory;

[0041] Figure 7 It is a schematic diagram of the fracturing construction of the present invention in which the wellbore trajectory is a horizontal trajectory;

[0042] Figure 8 A schematic diagram of an oil and gas enrichment area in an oil and gas reservoir in which the wellbore trajectory of the present invention is a horizontal trajectory;

[0043] Fig. 9 It is a schematic diagram of the tail injection and pre-production construction in which the wellbore trajectory of the present invention is a horizontal trajectory;

[0044] Fig.10 A schematic diagram of perforation construction in which the wellbore trajectory of the present invention is a wave-shaped trajectory;

[0045] Fig.11 A schematic diagram of a fracturing operation in which the wellbore trajectory of the present invention is a wavy trajectory;

[0046] Fig.12A schematic diagram of an oil and gas enrichment area in an oil and gas reservoir in which the wellbore trajectory of the present invention is a wavy trajectory;

[0047] Fig.13 It is a schematic diagram of the tail injection front production construction in which the wellbore trajectory of the present invention is a wavy trajectory;

[0048] Fig.14 It is a schematic diagram of the multi-well horizontal well injection and production construction of several horizontal well trajectories (including horizontal, flume and wave types) and vertical well combinations of the present invention;

[0049] Fig.15 It is a schematic diagram of multi-well horizontal well injection and production construction combining several horizontal well trajectories (including horizontal type, trough type and wave type) of the present invention. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work are within the scope of protection of the present invention.

[0051] like Figure 1 As shown, the present invention provides a horizontal well injection-production integrated method, comprising:

[0052] Determine the injection end and production end based on the comparison of the main oil and gas enrichment areas in the oil and gas reservoir or the injection volume and production volume, or the process measures to solve the sand and wax deposition problems;

[0053] forming an artificial seepage channel in the oil and gas reservoir between the injection end and the production end of the inclined well section and / or the horizontal well section passing through the oil and gas reservoir;

[0054] An oil pipe with an upper packer and a lower packer is run into the oil casing in the inclined well section and / or the horizontal well section where an artificial seepage channel has been formed;

[0055] The medium is injected from the injection end, and the oil and gas in the oil and gas reservoir are extracted from the production end. The medium enters the oil and gas reservoir near the injection end, and through the artificial seepage channel formed in the oil and gas reservoir between the injection end and the production end, the oil and gas in the oil and gas reservoir near the injection end are pushed to migrate to the production end, and then produced by the production end.

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

[0057] In some embodiments of the present invention, the injection end and the production end are determined according to the comparison between the main oil and gas enrichment area in the oil and gas reservoir or the injection amount and the production amount, including:

[0058] When the injection volume of the oil and gas reservoir is less than the production volume or the oil and gas are mainly concentrated in the inclined well section and / or the front end of the horizontal well, the tail end of the inclined well section and / or the horizontal well section is used as the injection end, and the front end of the inclined well section and / or the horizontal well section 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 inclined well section and / or the horizontal well section, and 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 inclined well section and / or the horizontal well section is pushed to migrate to the front end of the inclined well section and / or the horizontal well section. Under the action of the upper packer, oil and gas are produced from the oil casing annulus at the front end of the inclined well section and / or the horizontal well section.

[0059] When the injection volume of the oil and gas reservoir is greater than the production volume or the oil and gas are mainly enriched at the tail end of the inclined well section and / or the horizontal well section, the front end of the inclined well section and / or the horizontal well section is used as the injection end, and the tail end of the inclined well section and / or the horizontal well section is used as the production end. Injection is performed through the oil casing annulus at the front end of the inclined well section and / or the horizontal well section. 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 well section and / or the horizontal well section, and through the artificial seepage channel in the oil and gas reservoir, the oil and gas in the oil and gas reservoir near the front end of the inclined well section and / or the horizontal well section are pushed to migrate to the tail end of the inclined well section and / or the horizontal well section. Under the action of the lower packer, oil and gas are produced from the oil pipe at the tail end of the inclined well section and / or the horizontal well section.

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

[0061] Artificial seepage channels are formed in the oil and gas reservoirs in the inclined well section and / or horizontal well section through perforation and staged sand fracturing construction.

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

[0063] Perforation and staged sand fracturing are carried out from the injection end to the production end.

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

[0065] Perforation and staged sand fracturing are carried out in the direction of the oil and gas reservoirs around the wellbore at the production end.

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

[0067] Perforation and staged sand fracturing are carried out in the direction of the oil and gas reservoir around the wellbore between the upper packer and the lower packer.

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

[0069] The perforation and staged sand fracturing construction directions and human flow channels are designed according to the wellbore trajectories of different horizontal and inclined sections.

[0070] In some embodiments of the present invention, the wellbore trajectory includes a flume-type 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 injecting and producing horizontal wells between 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] Through perforation and fracturing operations, artificial seepage channels are formed in the oil and gas reservoir between the injection well and the production well;

[0074] The medium is injected from the injection well, and the oil and gas in the oil and gas reservoir are produced from the production well.

[0075] In some embodiments of the present invention, the plurality of wells includes a plurality of horizontal wells and zero to a plurality of vertical wells.

[0076] In order to better illustrate the present solution, the following embodiments are also provided.

[0077] Example 1

[0078] The injection-production integration method of this embodiment adopts the method of tail injection before production to perform injection-production integration construction on the inclined well section and the horizontal well section whose well trajectory is a trough-type trajectory.

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

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

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

[0082] S2, such as Figure 1 As shown, the inclined well sections 602 and 604 perforate into the soft formation, and the horizontal well section 603 perforates through the hard formation into the soft formation; Figure 2 As shown, combined with the construction conditions, the segmented sand fracturing construction technology is adopted to divide the wellbore into several sections, and sand fracturing is carried out in each section to form a complex fracture network, which is then connected and extended to form a fracture network channel.

[0083] S3, such as Figure 3 As shown, the oil pipe with upper and lower packers is lowered into the wellbore, the oil casing is closed (the wellhead oil pipe is closed, and the wellbore and the oil pipe annulus are opened). Since the upper and lower packers isolate the oil pipe and the wellbore annulus, the oil, gas and fracturing fluid in the soft formation can only enter the oil pipe and the wellbore annulus at the front end of the wellbore through the complex seam network, and finally flow to the ground, and form a relatively low-pressure area at the front end of the wellbore.

[0084] S4, such as Figure 4 As shown in the figure, when the pressure of the oil and gas layer is low, the oil and gas cannot flow to the ground, and fluid injection is required to produce oil. The injection fluid flows to the tail end of the wellbore through the oil pipe in the wellbore. Due to the action of the lower packer, the injection fluid can only enter the soft formation containing oil and gas (such as shale oil layer) through the complex seam network at the tail end of the wellbore. Since the pressure at the front end of the wellbore is low, the injection fluid pushes the oil and gas in the soft formation to flow to the front end of the wellbore and enter the wellbore, and finally flow to the ground.

[0085] Example 2

[0086] The injection-production integration method of this embodiment adopts the method of tail injection before production to perform injection-production integration construction on the inclined well section and the horizontal well section with a horizontal well trajectory.

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

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

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

[0090] S2, such as Figure 5 As shown, the inclined well section 702 perforates into the soft formation, and the horizontal well section 703 perforates up and down through the hard formation into the soft formation. Figure 6 As shown, combined with the construction conditions, the segmented sand fracturing construction technology can be adopted to divide the wellbore into several sections, and each section is subjected to sand fracturing to form a complex fracture network, which can then be connected and extended to form a fracture network channel.

[0091] S3, such as Figure 7 As shown, the oil pipe with upper and lower packers is lowered into the wellbore, the oil casing is closed (the wellhead oil pipe is closed, and the wellbore and the oil pipe annulus are opened). Since the upper and lower packers isolate the oil pipe and the wellbore annulus, the oil, gas and fracturing fluid in the soft formation can only enter the oil pipe and the wellbore annulus at the front end of the wellbore through the complex seam network, and finally flow to the ground, and form a relatively low-pressure area at the front end of the wellbore.

[0092] S4, such as Figure 8 As shown in the figure, when the pressure of the oil and gas layer is low, the oil and gas cannot flow to the ground, and fluid injection is required to produce oil. The injection fluid flows to the tail end of the wellbore through the oil pipe in the wellbore. Due to the action of the lower packer, the injection fluid can only enter the soft formation containing oil and gas (such as shale oil layer) through the complex seam network at the tail end of the wellbore. Since the pressure at the front end of the wellbore is low, the injection fluid pushes the oil and gas in the soft formation to flow to the front end of the wellbore and enter the wellbore, and finally flow to the ground.

[0093] Example 3

[0094] The injection-production integration method of this embodiment adopts the method of tail injection before production to perform injection-production integration construction on the inclined well section with a wavy well trajectory.

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

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

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

[0098] S2, such as Fig. 9 As shown, the inclined well sections 802 and 803 perforate the soft formation. Fig.10 As shown, combined with the construction conditions, the segmented sand fracturing construction technology can be adopted to divide the wellbore into several sections, and each section is subjected to sand fracturing to form a complex fracture network, which can then be connected and extended to form a fracture network channel.

[0099] S3, such as Fig.11 As shown, the oil pipe with upper and lower packers is lowered into the wellbore, the oil casing is closed (the wellhead oil pipe is closed, and the wellbore and the oil pipe annulus are opened). Since the upper and lower packers isolate the oil pipe and the wellbore annulus, the oil, gas and fracturing fluid in the soft formation can only enter the oil pipe and the wellbore annulus at the front end of the wellbore through the complex seam network, and finally flow to the ground, and form a relatively low-pressure area at the front end of the wellbore.

[0100] S4, such as Fig.12 As shown in the figure, when the pressure of the oil and gas layer is low, the oil and gas cannot flow to the ground, and fluid injection is required to produce oil. The injection fluid flows to the tail end of the wellbore through the oil pipe in the wellbore. Due to the action of the lower packer, the injection fluid can only enter the soft formation containing oil and gas (such as shale oil layer) through the complex seam network at the tail end of the wellbore. Since the pressure at the front end of the wellbore is low, the injection fluid pushes the oil and gas in the soft formation to flow to the front end of the wellbore and enter the wellbore, and finally flow to the ground.

[0101] Example 4

[0102] The injection-production integration method of this embodiment adopts a horizontal well group as an injection well and a vertical well group as a production well, and performs injection-production integration construction on the horizontal well group and the vertical well combination.

[0103] like Fig.13 As shown in the figure, the spacing and number of horizontal well groups and vertical well groups are designed according to the distribution of oil and gas reservoirs, the degree of fracture development, and the width of the fracturing. Figure 1-Figure 12 As shown, combined with the construction conditions, the staged sand fracturing construction technology can be used to perform sand fracturing on the horizontal well group and the vertical well group to form a complex fracture network, connect the wells, extend the complex fracture network, and form an inter-well fracture network channel.

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

[0105] When the formation pressure is low, oil and gas cannot flow to the ground or the yield flowing to the ground is low, and liquid injection is required for oil recovery. According to the location of oil and gas enrichment, the horizontal well group and the vertical well group are determined as injection wells or production wells. According to the location of the injection end, the packer can be lowered and liquid can be injected into the injection well. The injection liquid enters the complex fracture network in the oil and gas reservoir due to high pressure, and pushes the oil and gas in the oil and gas reservoir into the wellbore of the production well, and finally flows to the ground.

[0106] Example 5

[0107] In this embodiment, on the basis of embodiment 4, the vertical well group is changed into another group of horizontal wells, that is, two groups of horizontal wells, such as Fig.14 As shown, one group of horizontal wells is an injection well group, and the other group of horizontal wells is a production well group.

[0108] In summary, the present invention utilizes the ultra-long distance of the horizontal well, artificially establishes a seepage channel, and applies the injection-production integrated technology, so as to exploit a large amount of oil and gas in the horizontal well and the surrounding oil and gas reservoirs, reduce the storage volume of the remaining oil and gas or the difficult-to-recover oil and gas in the oil and gas reservoirs, and improve the recoverable coefficient of the oil and gas reservoirs; and by injecting gas liquid to increase the formation pressure, the oil and gas self-flowing time can be extended, and the economic benefits can be improved.

[0109] Finally, it should be noted that the above 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 aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A horizontal well injection-production integrated method, characterized in that: include: Determine the injection end and production end based on the main oil and gas enrichment area in the oil and gas reservoir or the comparison between the injection volume and the production volume; forming an artificial seepage channel in the oil and gas reservoir between the injection end and the production end of the inclined well section and / or the horizontal well section passing through the oil and gas reservoir; An oil pipe with an upper packer and a lower packer is run into the oil casing of the inclined well section and / or the horizontal well section where the artificial seepage channel has been formed; The medium is injected from the injection end, and the oil and gas in the oil and gas reservoir are extracted from the production end.

2. A horizontal well injection-production integrated method according to claim 1, characterized in that: The method of determining the injection end and the production end according to the comparison between the main oil and gas enrichment area in the oil and gas reservoir or the injection volume and the production volume includes: When the injection volume of the oil and gas reservoir is less than the production volume or the oil and gas are mainly concentrated in the inclined well section and / or the front end of the horizontal well, the tail end of the inclined well section and / or the horizontal well section is used as the injection end, and the front end of the inclined well section and / or the horizontal well section is used as the production end, and the oil and gas are produced from the oil casing annulus at the front end of the inclined well section and / or the horizontal well section; When the injection volume of the oil and gas reservoir is greater than the production volume or the oil and gas are mainly enriched at the tail end of the inclined well section and / or the horizontal well section, the front end of the inclined well section and / or the horizontal well section is used as the injection end, and injection is carried out through the oil casing annulus at the front end of the inclined well section and / or the horizontal well section, and the tail end of the inclined well section and / or the horizontal well section is used as the production end.

3. A horizontal well injection-production integrated method according to claim 1, characterized in that: The method of forming an artificial seepage channel in the oil and gas reservoir between the injection end and the production end of the inclined well section and / or the horizontal well section passing through the oil and gas reservoir comprises: Artificial seepage channels are formed in the oil and gas reservoirs in the inclined well section and / or horizontal well section through perforation and staged sand fracturing construction.

4. A horizontal well injection-production integrated method according to claim 3, characterized in that: The method of forming an artificial seepage channel in the oil and gas reservoir between the injection end and the production end of the inclined well section and / or the horizontal well section passing through the oil and gas reservoir comprises: Perforation and staged sand fracturing are carried out from the injection end to the production end.

5. The horizontal well injection-production integrated method according to claim 3, characterized in that: The method of forming an artificial seepage channel in the oil and gas reservoir between the injection end and the production end of the inclined well section and / or the horizontal well section passing through the oil and gas reservoir comprises: Perforation and staged sand fracturing are carried out in the direction of the oil and gas reservoirs around the wellbore at the production end.

6. A horizontal well injection-production integrated method according to claim 3, characterized in that: The method of forming an artificial seepage channel in the oil and gas reservoir between the injection end and the production end of the inclined well section and / or the horizontal well section passing through the oil and gas reservoir comprises: Perforation and staged sand fracturing are carried out in the direction of the oil and gas reservoir around the wellbore between the upper packer and the lower packer.

7. The horizontal well injection-production integrated method according to claim 3, characterized in that: The method of forming an artificial seepage channel in the oil and gas reservoir between the injection end and the production end of the inclined well section and / or the horizontal well section passing through the oil and gas reservoir comprises: The perforation and staged sand fracturing construction directions and human flow channels are designed according to the wellbore trajectories of different horizontal and inclined sections.

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

9. The horizontal well injection-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 injecting and producing horizontal wells between 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; By perforating and fracturing operations, an artificial seepage channel is formed in the oil and gas reservoir between the injection well and the production well; The medium is injected from the injection well, and the oil and gas in the oil and gas reservoir are produced from the production well.

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

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