Horizontal well subsection plugging and mining water-reducing and oil-increasing flow field structure

Abstract

The utility model discloses a horizontal well subsection plugging and mining water-reducing and oil-increasing flow field structure which comprises a pipe string combination arranged in a horizontal well open hole section, and the pipe string combination comprises a liquid adjusting pipe string and at least one first packer arranged on the periphery of the liquid adjusting pipe string. The liquid adjusting pipe string is divided into at least two pipe string sections by the first packer; a liquid adjusting hole is formed in each pipe string subsection; in the open hole section of the horizontal well, the space between the liquid adjusting pipe string and the open hole section of the horizontal well is divided into at least two separation cavities by the first packer; and the liquid adjusting holes are communicated with the corresponding pipe string sections and the separation cavities. The liquid adjusting pipe string and the packers are arranged in the horizontal well, the inner cavity of the horizontal well is divided into the separation cavities, the water content of produced liquid of all the separation cavities can be conveniently obtained, plugging and water control can be conveniently conducted on stratums outside the separation cavities, and integration of water control, water plugging and oil extraction is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of oilfield development, in particular to a horizontal well sectional plugging production reduction, water production reduction and oil production increase flow field structure. Background Technique

[0002] During the oilfield development process of horizontal wells, due to reasons such as flow friction, reservoir heterogeneity and physical property time-variation, especially the characteristics of high-speed development of offshore oilfields, there will be relatively serious heel effects and unbalanced liquid supply in horizontal wells, resulting in a certain degree of edge-bottom water breakthrough problem in horizontal wells, and there is a risk of unbalanced utilization in the horizontal well section and too fast water influx in local well sections. For strongly water-driven marine sandstone oil reservoirs, this problem is even more serious. Because the strongly water-driven development mode has a strong transformation effect on the physical properties of the reservoir, after long-term high-intensity scouring of the reservoir, the physical properties change very significantly. Experimental data show that the reservoir permeability increases significantly with the continuous increase of water influx. Affected by the time-variation of physical properties, the reservoir heterogeneity will be further aggravated. This dynamically formed heterogeneity may even exceed the original heterogeneity of the reservoir, forming local preferential channels, and exacerbating the unbalanced liquid supply in the horizontal well section and the local breakthrough problem of edge-bottom water.

[0003] Currently, the commonly used horizontal well water control technologies all focus on wellbore water control, which can be divided into passive water control technologies and active water control technologies. Passive water control technologies include common water control process technologies such as central pipes, ICDs, ACIDs and C-ACIDs. Such water control technologies need to set water control parameters in advance and cannot be changed after being put into the formation, and cannot cope with the heterogeneity caused by physical property time-variation and other unexpected situations. For example, when setting water control parameters, only the physical property characteristics near the wellbore are considered, and formation characteristics such as interlayers, fractures or other heterogeneities inside the formation cannot be considered. Therefore, such water control technologies often have the problem of ineffective water control. The current active water control technology is mainly the sectional water control technology. This technology performs double segmentation on the horizontal well, segmenting between the formation and the horizontal well and synchronously segmenting inside the horizontal well, realizing measurable and adjustable liquid volume for each segment, and can adjust the liquid volume in a timely manner according to the water cut of each segment to achieve maximum water control. It is a relatively effective water control technology at present. However, as a wellbore water control technology, it can only adjust the fluid passing capacity of the wellbore and cannot control the flow around the formation. Therefore, the wellbore water control technology has a short effective period and cannot fundamentally solve the problem of too fast water production in horizontal wells. Content of the Utility Model

[0004] The technical problem to be solved by the utility model is to provide a horizontal well sectional plugging production reduction, water production reduction and oil production increase flow field structure.

[0005] The technical solution adopted by the present utility model to solve its technical problems is: to provide a horizontal well sectional plugging production reduction and water production increase and oil production increase flow field structure, including a pipe string assembly placed in the open hole section of the horizontal well and a plugging area formed by the penetration and plugging of a plugging agent in the formation; the pipe string assembly includes a liquid regulating pipe string and at least one first packer arranged on the outer periphery of the liquid regulating pipe string;

[0006] The first packer divides the liquid regulating pipe string into at least two pipe string segments; each pipe string segment is provided with a liquid regulating hole; in the open hole section of the horizontal well, the first packer divides the space between the liquid regulating pipe string and the open hole section of the horizontal well into at least two separated cavities; the liquid regulating hole communicates with the corresponding pipe string segment and the separated cavity; the plugging area is located outside at least one of the separated cavities.

[0007] In some embodiments, the horizontal well sectional plugging production reduction and water production increase and oil production increase flow field structure further includes at least a measuring instrument for monitoring the produced liquid volume and water cut in the separated cavity; the measuring instrument is arranged in each separated cavity and / or at the wellhead.

[0008] In some embodiments, the pipe string assembly further includes a water control pipe string sleeved outside the liquid regulating pipe string and at least one second packer; the first packer is arranged in the cavity between the liquid regulating pipe string and the water control pipe string, and the second packer is correspondingly arranged on the outer periphery of the water control pipe string;

[0009] In the open hole section of the horizontal well, at least one first packer divides the cavity between the liquid regulating pipe string and the water control pipe string into at least two flow cavities, and at least one second packer divides the space between the outer periphery of the water control pipe string and the inner wall of the open hole section of the horizontal well into at least two independent cavities; each flow cavity communicates with a corresponding independent cavity to form the separated cavity.

[0010] In some embodiments, the water control pipe string includes a pipe string main body and a fluid control valve arranged on the pipe string main body.

[0011] In some embodiments, the water control pipe string includes a particulate filling layer.

[0012] In some embodiments, the pipe string assembly further includes a mud and sand prevention pipe string sleeved outside the water control pipe string.

[0013] In some embodiments, the mud and sand prevention pipe string is a mechanical screen pipe, a perforated pipe or formed by gravel packing.

[0014] In some embodiments, the pipe string assembly further includes a mud and sand prevention pipe string sleeved outside the liquid regulating pipe string.

[0015] In some embodiments, the anti-silt and sand pipe string is a mechanical screen pipe, a perforated pipe, or formed by gravel packing.

[0016] The beneficial effects of the present utility model are as follows: By arranging the liquid adjusting pipe string and the packer in the horizontal well, the internal chamber of the horizontal well is divided into separated chambers, which is convenient for obtaining the water cut of the produced liquid in each separated chamber and plugging and controlling water in the formation outside the separated chamber, realizing the integration of water control, water plugging, and oil production; It can transform the flow field in the deep formation, artificially change the original physical property distribution of the formation, plug water in the deep formation, solve the problem of edge and bottom water breakthrough from the source, achieve the maximum water control effect, and is generally applicable to the horizontal well production method. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present utility model will be further described below in conjunction with the drawings and embodiments. In the drawings:

[0018] Figure 1 is a schematic structural diagram of the horizontal well sectional plugging, water production reduction, and oil production increase flow field structure according to an embodiment of the present utility model;

[0019] Figure 2 is a schematic structural diagram of the horizontal well sectional plugging, water production reduction, and oil production increase flow field structure according to another embodiment of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] In order to have a clearer understanding of the technical features, objectives, and effects of the present utility model, the specific embodiments of the present utility model will now be described in detail with reference to the drawings.

[0021] As Figure 1 shown, the horizontal well sectional plugging, water production reduction, and oil production increase flow field structure according to an embodiment of the present utility model may include a horizontal well and a pipe string combination. The pipe string combination is lowered into the horizontal wellbore open hole section 100 of the horizontal well.

[0022] Among them, the pipe string combination includes a liquid adjusting pipe string 10 and at least one first packer 11 arranged on the outer periphery of the liquid adjusting pipe string 10.

[0023] The liquid adjusting pipe string 10 may include a pipe string main body and a plurality of liquid adjusting holes 12 arranged on the pipe string main body. When the pipe string combination has two or more first packers 11, all the first packers 11 are arranged at intervals along the axial direction of the liquid adjusting pipe string 10. At least one first packer 11 divides the liquid adjusting pipe string 10 into at least two pipe string segments; one or more liquid adjusting holes 12 are provided on each pipe string segment, and each liquid adjusting hole 12 penetrates the pipe wall of the liquid adjusting pipe string 10 to communicate the inner and outer space of the corresponding pipe string segment.

[0024] The liquid regulating hole 12 is provided with an opening and closing mechanism such as a valve for controlling the opening and closing and the opening degree of the liquid regulating hole 12. The flow rate can be adjusted by controlling the opening degree. The opening and closing mechanism is connected to the control system on the ground, so that the opening and closing of the liquid regulating hole 12 can be remotely controlled on the ground.

[0025] In the open hole section 100 of the horizontal well, the first packer 11 abuts between the outer peripheral surface of the liquid regulating pipe string 10 and the inner wall surface of the open hole section 100 of the horizontal well, thereby dividing the space between the liquid regulating pipe string 10 and the open hole section 100 of the horizontal well into at least two separation chambers 110 arranged along the length direction of the open hole section 100 of the horizontal well. The pipe wall of each pipe string segment of the liquid regulating pipe string 10 forms the inner boundary of the corresponding separation chamber 110. The liquid regulating hole 12 on the pipe string segment is used to communicate the separation chamber 110 and the internal channel of the liquid regulating pipe string 10. The liquid regulating hole 12 is used for the produced liquid to enter the liquid regulating pipe string 10 and then be transported to the ground along the liquid regulating pipe string 10.

[0026] Furthermore, in order to detect and obtain the produced liquid volume and water cut of the separation chamber 110, the measuring instrument may include a detector arranged at the wellhead. By switching the liquid regulating valves of each separation chamber 110, the liquid production volume and water cut of the corresponding well section of each separation chamber 110 are detected; or, instruments such as detectors, tracers, and optical fibers are installed in each separation chamber 110 of the horizontal well to directly detect and interpret the liquid production volume and water cut of each separation chamber 110. Or, a measuring instrument is provided in each separation chamber 110. The measuring instrument may include, but is not limited to, one or more of a pressure gauge, a flow meter, and a thermometer. The measuring instrument is connected to the control system on the ground, and the detection signal is sent to the control system; the staff can monitor on the ground.

[0027] The horizontal well sectional plugging production reduction and water injection enhancement oil flow field structure of this embodiment further includes a plugging area 120, which is formed by the penetration and plugging of a plugging agent in the formation. The plugging area 120 is located outside at least one separation chamber 110.

[0028] The method for determining the position of the plugging zone 120 is as follows: In the production of horizontal wells, the water cut of the produced fluid passing through each separation chamber 110 is detected respectively. The separation chamber 110 with the water cut of the produced fluid reaching the relatively high water cut preset value (water cut ≥ 60%) is taken as the relatively high water cut well section. After determining the separation chamber 110 with the water cut of the produced fluid reaching the relatively high water cut preset value, taking this separation chamber 110 as the relatively high water cut well section, the liquid regulating hole 12 in this separation chamber 110 is opened or kept open, so that the relatively high water cut well section is in communication with the internal channel of the liquid regulating pipe string 10. The liquid regulating hole 12 corresponding to the separation chamber 110 with the water cut of the produced fluid not reaching the relatively high water cut preset value is closed, so that the separation chamber 110 is not in communication with the internal channel of the liquid regulating pipe string 10 and is in a cut-off state. Plugging agent is injected into the liquid regulating pipe string 10, so that the plugging agent enters the formation outside the relatively high water cut well section through the opened liquid regulating hole 12 and the relatively high water cut well section; the plugging agent diffuses in the formation outside the relatively high water cut well section and forms the plugging zone 120.

[0029] The water cut of the relatively high water cut well section is ≥ 60%. According to the heterogeneity of the formation and the distribution of physical properties, the plugging zone 120 formed by the diffusion of the plugging agent in the formation can be a regular polygon, an ellipse, etc., or an irregular shape. According to the formation characteristics and the water production situation of the horizontal well, through deep plugging with the plugging agent, only the high permeability zone with relatively large pore throats can be plugged, or all large and small pores can be directly plugged. The plugging agent is selected from chemical plugging agents, solid particle plugging agents or microbial plugging agents.

[0030] It can be understood that according to the actual situation, among all the separation chambers 110, there will be one separation chamber 110 with the water cut of the produced fluid reaching the relatively high water cut preset value, and there will also be two or more separation chambers 110 with the water cut of the produced fluid reaching the relatively high water cut preset value. Therefore, the plugging zone 120 formed by the plugging agent can be outside one separation chamber 110, or outside two or more separation chambers 110.

[0031] As Figure 2 shown, the horizontal well sectional plugging and water production reduction and oil production increase flow field structure of another embodiment of the present invention may include a horizontal well and a pipe string combination. The pipe string combination is lowered into the horizontal wellbore section 100 of the horizontal well.

[0032] In this embodiment, the pipe string combination includes a liquid regulating pipe string 10, a water control pipe string 20 sleeved outside the liquid regulating pipe string 10, a mud and sand prevention pipe string 30 sleeved outside the water control pipe string 20, at least one first packer 11 and at least one second packer 21.

[0033] The liquid regulating pipe string 10 is spaced from the water control pipe string 20, and a chamber is formed therebetween; the first packer 11 is disposed in the chamber between the liquid regulating pipe string 10 and the water control pipe string 20, dividing the liquid regulating pipe string 10 into at least two pipe string segments, and at the same time dividing the chamber between the liquid regulating pipe string 10 and the water control pipe string 20 into at least two flow chambers 101 distributed along the axial direction of the liquid regulating pipe string 10. The flow chambers 101 are relatively independent and not connected to each other.

[0034] The liquid regulating pipe string 10 may include a pipe string body and a plurality of liquid regulating holes 12 provided on the pipe string body; one or more liquid regulating holes 12 are provided on each pipe string segment, and each liquid regulating hole 12 penetrates the pipe wall of the liquid regulating pipe string 10, communicating the inner and outer spaces of the corresponding pipe string segment. Therefore, one or more liquid regulating holes 12 are also provided in each flow chamber 101, and are communicated with the internal channel of the liquid regulating pipe string 10 through the liquid regulating holes 12.

[0035] The liquid regulating hole 12 is provided with an opening and closing mechanism such as a valve for controlling the opening and closing and the opening degree of the liquid regulating hole 12, and the flow rate can be adjusted by controlling the opening degree. The opening and closing mechanism is connected to the control system on the ground, so that the opening and closing of the liquid regulating hole 12 can be remotely controlled on the ground.

[0036] The second packer 21 is disposed on the outer periphery of the water control pipe string 20, and can divide the external space of the water control pipe string 20 into sub-chambers distributed along the axial direction of the water control pipe string 20.

[0037] In the horizontal well open hole section 100, the second packer 21 abuts between the outer periphery of the water control pipe string 20 and the inner wall of the horizontal well open hole section 100, thereby dividing the space between the outer periphery of the water control pipe string 20 and the inner wall of the horizontal well open hole section 100 into at least two independent chambers 102. Each second packer 21 corresponds to the outside of a first packer 11, that is: in the radial direction of the horizontal well open hole section 100, the first packer 11 and the second packer 21 are in a straight line. In this way, each independent chamber 102 is annularly arranged outside a flow chamber 101, and an independent chamber 102 communicates with a corresponding flow chamber 101 in the radial direction to form a separation chamber 110.

[0038] It can be understood that when there are two flow chambers 101 and two independent chambers 102, two separation chambers 110 can be formed outside the liquid regulating pipe string 10; when there are three or more flow chambers 101 and independent chambers 102 respectively, the formed separation chambers 110 are also three or more.

[0039] To detect the produced fluid volume and water cut of the separated chamber 110, the measuring instrument may include a detector installed at the wellhead. By switching the fluid regulating valves of each separated chamber 110, the produced fluid volume and water cut of the corresponding well section of each separated chamber 110 can be detected; or, in the horizontal well, detectors, tracers, optical fibers and other instruments are installed in each separated chamber 110 to directly detect and interpret the produced fluid volume and water cut of each separated chamber 110. Or, a measuring instrument is provided in each separated chamber 110, and the measuring instrument may include one or more of a pressure gauge, a flowmeter, and a thermometer. The measuring instrument is connected to the control system on the ground, and the detection signal is sent to the control system; the staff can monitor on the ground.

[0040] The water control pipe string 20 may further include a pipe string body and fluid control valves (ICD\AICD\C-AICD) provided on the pipe string body; or, the water control pipe string includes a particulate filling layer.

[0041] The anti-silt and sand pipe string 30 is a mechanical screen pipe, a perforated pipe or formed by gravel packing.

[0042] The water control pipe string 20 and the anti-silt and sand pipe string 30 of the pipe string combination can be specifically set according to the formation characteristics as required. For example, in some embodiments, the pipe string combination includes a fluid regulating pipe string 10 and a water control pipe string 20, and is divided into chambers through the first packer 11 and the second separated chamber to form the separated chamber 110. Or, the pipe string combination includes a fluid regulating pipe string 10 and an anti-silt and sand pipe string 30, and is divided into chambers through the first packer 11 to form the separated chamber 110.

[0043] According to the formation type and wellbore completion requirements, the water control pipe string 20 and the anti-silt and sand pipe string 30 are combined differently to meet different application scenarios. The anti-silt and sand pipe string 30 has an anti-silt function or an anti-sand function, or an anti-silt and anti-sand function according to the actual situation, and has different pore sizes according to the requirements of different functions.

[0044] During the production of the horizontal well, the reservoir fluid (i.e., the produced fluid) of the formation sequentially passes through the independent chamber 102, the flow chamber 101 and the fluid regulating hole 12 into the fluid regulating pipe string 10, and then is transported to the ground along the fluid regulating pipe string 10.

[0045] The horizontal well sectional plugging production and water reduction and oil increase flow field structure of this embodiment further includes a plugging area 120, which is formed by the penetration and plugging of the plugging agent in the formation. The plugging area 120 is located outside at least one separated chamber 110.

[0046] The method for determining the position of the plugging zone 120 is as follows: During the production of a horizontal well, the water cut of the produced fluid passing through each separation chamber 110 is detected respectively. The separation chamber 110 with the water cut of the produced fluid reaching the predetermined value of relatively high water cut is taken as the relatively high water cut well section. After determining the separation chamber 110 with the water cut of the produced fluid reaching the predetermined value of relatively high water cut, taking this separation chamber 110 as the relatively high water cut well section, the liquid regulating hole 12 in this separation chamber 110 is opened or kept open, so that this relatively high water cut well section is in communication with the internal channel of the liquid regulating pipe string 10. The liquid regulating hole 12 corresponding to the separation chamber 110 with the water cut of the produced fluid not reaching the predetermined value of relatively high water cut is closed, so that the separation chamber 110 is not in communication with the internal channel of the liquid regulating pipe string 10 and is in a cut-off state. Plugging agent is injected into the liquid regulating pipe string 10, so that the plugging agent enters the formation outside the relatively high water cut well section through the opened liquid regulating hole 12 and the relatively high water cut well section; the plugging agent diffuses in the formation outside the relatively high water cut well section and forms a plugging zone 120.

[0047] The water cut of the relatively high water cut well section ≥ 60%. According to the heterogeneity of the formation and the distribution of physical properties, the plugging zone 120 formed by the diffusion of the plugging agent in the formation can be a regular polygon, an ellipse, etc., or an irregular shape. According to the formation characteristics and the water production situation of the horizontal well, by using the plugging agent for deep plugging, only the high permeability zone with relatively large pore throats can be plugged, or all the large and small pores can be directly plugged. The plugging agent is selected from chemical plugging agents, solid phase particle plugging agents or microbial plugging agents.

[0048] It can be understood that according to the actual situation, among all the separation chambers 110, the water cut of the produced fluid in one separation chamber 110 will reach the predetermined value of high water cut, and the water cut of the produced fluid in two or more separation chambers 110 will also reach the predetermined value of high water cut. Therefore, the plugging zone 120 formed by the plugging agent can be outside one separation chamber 110, or outside two or more separation chambers 110.

[0049] In Figure 1 、 Figure 2 In the flow field structure of sectional plugging for water production reduction and oil production increase of the horizontal well shown, three separation chambers 110 are taken as an example. When the water cut of the produced fluid in the separation chamber 110 located in the middle position reaches the predetermined value of relatively high water cut, plugging agent is injected to plug the formation outside this separation chamber 110, and the plugging agent expands in the formation to form a certain area (plugging zone 120). The formation storage liquid can still enter the remaining separation chambers 110, and the storage liquid near the plugging zone 120 can flow along the periphery of the plugging zone 120 into the adjacent separation chamber 110. The flow direction of the fluid is as shown by the streamlines in Figure 1 、 Figure 2 to achieve the control of the bypass flow in the formation.

[0050] The above are only embodiments of the present utility model, and thus do not limit the patent scope of the present utility model. Any equivalent structural or equivalent process transformations made by using the content of the specification and drawings of the present utility model, or directly or indirectly applied in other related technical fields, shall similarly be included within the patent protection scope of the present utility model.

Claims

1. A flow field structure for reducing water and increasing oil production by staged plugging and production in a horizontal well, characterized in that: It includes a pipe string assembly lowered into the open hole section of the horizontal well, and a plugging area formed by the plugging agent penetrating and plugging in the formation; the pipe string assembly includes a liquid regulating pipe string and at least one first packer arranged on the periphery of the liquid regulating pipe string; The first packer divides the fluid regulating pipe string into at least two pipe string segments; each of the pipe string segments is provided with a fluid regulating hole; in the open hole section of the horizontal well, the first packer divides the space between the fluid regulating pipe string and the open hole section of the horizontal well into at least two separation chambers; the fluid regulating holes connect the corresponding pipe string segments and the separation chambers; the plugging area is located outside at least one of the separation chambers.

2. The horizontal well segmented plugging and production flow field structure for reducing water and increasing oil production according to claim 1 is characterized in that: The horizontal well segmented plugging and production water reduction and oil increase flow field structure also includes at least a measuring instrument for monitoring the produced fluid volume and water content in the partition chamber; the measuring instrument is arranged in each of the partition chambers and / or at the wellhead.

3. The horizontal well segmented plugging and production flow field structure for reducing water and increasing oil production according to any one of claims 1 to 2, characterized in that: The pipe string assembly also includes a water control pipe string sleeved outside the liquid regulating pipe string and at least one second packer; the first packer is arranged in a chamber between the liquid regulating pipe string and the water control pipe string, and the second packer is arranged on the outer periphery of the water control pipe string corresponding to the first packer; In the open hole section of the horizontal well, at least one of the first packers divides the chamber between the liquid regulating pipe string and the water control pipe string into at least two flow chambers, and at least one of the second packers divides the space between the outer periphery of the water control pipe string and the inner wall of the open hole section of the horizontal well into at least two independent chambers; each of the flow chambers is connected to a corresponding independent chamber to form the separation chamber.

4. The horizontal well segmented plugging and production flow field structure for reducing water and increasing oil production according to claim 3 is characterized in that: The water control pipe string comprises a pipe string body and a fluid control valve arranged on the pipe string body.

5. The horizontal well segmented plugging and production flow field structure for reducing water and increasing oil production according to claim 3 is characterized in that: The water control pipe string includes a particle filling layer.

6. The horizontal well segmented plugging and production flow field structure for reducing water and increasing oil production according to claim 3 is characterized in that: The pipe string assembly also includes a mud and sand prevention pipe string sleeved on the outer periphery of the water control pipe string.

7. The horizontal well segmented plugging and production flow field structure for reducing water and increasing oil production according to claim 6 is characterized in that: The mud and sand prevention pipe string is a mechanical screen pipe, a perforated pipe or is formed by gravel filling.

8. The horizontal well segmented plugging and production flow field structure for reducing water and increasing oil production according to any one of claims 1-2, characterized in that: The pipe string assembly also includes a mud and sand prevention pipe string sleeved outside the liquid regulating pipe string.

9. The horizontal well segmented plugging and production flow field structure for reducing water and increasing oil production according to claim 8, characterized in that: The mud and sand prevention pipe string is a mechanical screen pipe, a perforated pipe or is formed by gravel filling.

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