A horizontal well water control and sand drainage system

Abstract

The present invention discloses a horizontal well water control and sand discharging system. This system includes: a screen pipe, and the fluid passing through the screen pipe enters a sedimentator which is used for sedimenting the sediment in the fluid; a water control and sand discharging mechanism which includes a cation aggregation plate. When the cation aggregation plate is electrified, it is used to adsorb the sediment flowing through the sedimentator. By utilizing the density and charge property differences between water and clay, after discharging, the anions are dissipated to the ground, while the cations aggregate on the cation aggregation plate. At this time, for the water and sediment passing through this area, the sediment generally carries anions and will be adsorbed by the water control and sand discharging mechanism and gradually aggregate, so that the water flow channel will gradually decrease and the water volume will decrease accordingly. When the cation aggregation plate no longer releases cations, the sediment loses its adhesion and is uniformly discharged from the wellbore, thereby achieving the purpose of water control and sand discharging.

Description

Technical Field

[0001] The present invention relates to hydrate and high-silt gas well exploitation technologies, and particularly to a horizontal well water control and sand discharging system. Background Art

[0002] In China's sea areas, hydrates generally occur in shallow soft and unconsolidated formations with high water saturation, even close to high aquifers. Therefore, during pressure reduction exploitation, it is extremely easy for formation sand production to occur due to pore water migration, and even communicate with the aquifer, resulting in a huge amount of water and sand production in the wellbore in a short period, burying the wellbore. At the same time, formation collapse causes wellbore deformation and even instability, triggering more serious downhole complex situations, seriously affecting the long-term stable production and high-efficiency production increase of hydrates. It can be seen that during the hydrate exploitation process, reasonably blocking - dredging - discharging the formation water and sand around the wellbore will become one of the keys to commercial hydrate exploitation.

[0003] Currently, there is no relevant water control and sand discharging mechanism or device for hydrate exploitation and high-silt sand layer gas resource exploitation. The existing water control technologies in the fields of oil and gas reservoirs and coalbed methane are mostly used to solve complex situations such as water flooding and water gushing faced during oil well exploitation, developing oil drainage and water control devices, or using the method of directly lowering sectional packers for cement injection to block water in the fields of coalbed methane, etc. For example, common water control and sand discharging devices in the oil and gas industry are: ① Passive flow control device (inflow control device, ICD), which is segmented by means of an external packer. However, the mechanical sectional tool used in this water control technology increases the difficulty of gravel packing, and the water control process cannot take into account the sand control requirements of gravel packing. After the water control tool is lowered into the well, it cannot be adjusted in real time according to the dynamic changes of oil and water; ② Oil-water viscosity difference flow control and self-adaptive flow control device (autonomous inflow control device, AICD). However, due to the small resistance to the crude oil flowing into the wellbore, the role of AICD in initially balancing the production profile is limited, and it is easy to cause the bottom water to quickly approach the wellbore to form a "water flooding area"; ③ The new composite water control device (composite autonomous inflow control device, C-AICD) realizes balancing the production profile in the initial production stage (low water cut), and automatically suppressing water according to the changes in fluid characteristics in the middle and later stages (medium and high water cut). With the concept of full-life water control, it realizes water control and oil stabilization in production wells. For details, see the literature "Pan Hao, Guo Yi, Cao Yanfeng, etc. Design and application effect evaluation of C-AICD water control for a horizontal well in the sea [J]. Applied Petrochemical Technology, 2021, 40(10): 34 - 38."

[0004] The above water control devices either use methods such as cement injection to seal off water or utilize the differences in the properties of oil and water to control water production and produce oil. They all share a common feature, that is, water control designs are carried out for specific oil extraction fields. However, the exploitation of natural gas hydrates or other muddy water-bearing gas reservoirs does not involve oil layers. The substances entering the wellbore include formation mud and sand, formation water, and decomposed gas of natural gas hydrates. In addition, there are also a small amount of construction residues, etc. Therefore, it is impossible to design a water control mechanism using the viscosity coefficient difference between oil and water. The existing oil reservoir water control devices are not applicable in the above resource development, and it is necessary to redesign a water control and sand removal system for the problem of bottom water coning in horizontal wells of hydrates and high muddy water-bearing gas reservoirs.

[0005] Currently, for the development of high muddy water-bearing gas reservoirs and hydrate reservoirs, in order to achieve the goal of long-term stable production, in the field of bottom water ridge advance, the key technical problems to be solved mainly include:

[0006] 1. In the horizontal extension direction of the horizontal well, since the water decomposed from hydrates, gas, etc. will carry formation sand into the near-wellbore area, restricted by the pore structure and sand removal capacity, after the mud and sand bridge and accumulate in the micropores, it will cause a composite blockage of water blockage and sand blockage, resulting in a significant reduction in the gas-phase permeability of the original channel and a decrease in production capacity.

[0007] 2. During the decomposition process of hydrates, the main substances entering the wellbore include methane gas, decomposed water, original pore water, and formation mud and sand particles, mainly these three substances. Among them, the gas migration resistance is small and the requirement for permeability is low. However, as the exploitation progresses, the water production rates faced by different horizontal sections show differences. If water control is not carried out, the pore structure around the wellbore will be flooded in a short period, and the water lock effect of the microscopic pore structure is obvious, which will affect the gas production. Therefore, during different exploitation periods, water control and sand removal operations should be carried out in combination with the problem of bottom water ridge advance to adjust the liquid production profile balance and extend the stable production period. Summary of the Invention

[0008] The purpose of the present invention is to overcome the above-mentioned deficiencies of the prior art and provide a horizontal well water control and sand removal system to achieve full-life water production and sand production control of restricting flow in the medium term and removing sand in the later stage, ensure the smoothness of the gas production channel in the near-well zone, maximize the excavation of production capacity, and ensure the stable production period.

[0009] To achieve the above purpose, the technical solution of the present invention is:

[0010] A horizontal well water control and sand removal system includes:

[0011] A screen pipe, and the fluid after passing through the screen pipe enters a sedimentator, and the sedimentator is used to precipitate the sediment in the fluid;

[0012] A water control and sand removal mechanism, including a cation aggregation plate, which is used to adsorb the sediment flowing through the sedimentator when the cation aggregation plate is electrified.

[0013] Since the clay contained in the mud and sand is mainly composed of silicates, carbonate rocks, etc., and its particles are negatively charged as a whole, the present invention controls water and discharges sand by utilizing the density and charge differences between water and clay. When the battery is discharged, the anions are grounded and dissipated, and the cations are gathered on the cation aggregation plate. At this time, the water and mud and sand passing through the area generally carry anions, which will be adsorbed by the water control and sand discharge mechanism and gradually gather. Then the water flow channel will gradually decrease, and the water volume will decrease accordingly. When the cation aggregation plate does not release cations, the mud and sand lose their adhesion and are uniformly discharged from the wellbore, thereby achieving the purpose of controlling water and discharge sand.

[0014] Furthermore, the precipitator is spiral-shaped to separate the water and mud and sand entering the precipitator. The water and sand entering the area are separated by a spiral method. Since the density of mud and sand is greater than that of water, when the flow rate is low, after the mud and water pass through this section, sand will be deposited in the area with a larger curvature, and water will be produced. When the cation aggregation plate does not release cations, the mud and sand lose their adhesion and are uniformly discharged from the wellbore. The flow rate in the spiral precipitator will also increase, so that the sedimented mud and sand inside it can be discharged, achieving the purpose of slow or full discharge of mud and sand.

[0015] Furthermore, the screen pipe includes an outer base pipe and an inner base pipe arranged inside the outer base pipe, and an annular channel is formed between the inner base pipe and the outer base pipe; a sand retaining medium is arranged in a part of the outer base pipe; the annular channel is divided into two sections, namely a first annular channel section opposite to the sand retaining medium and a second annular channel section for installing the precipitator and the water control and sand discharge mechanism; a convergence port is formed at the junction of the first annular channel section and the second annular channel section, and the starting end of the precipitator is connected to the convergence port. In this way, the fluid that has been initially sand-proofed by the screen pipe can be converged into the spiral precipitator, and because the spiral precipitator and the water control and sand discharge mechanism are installed inside the screen pipe, the structure is more compact.

[0016] Furthermore, the cation aggregation plates are made of metal, and are provided in two pieces and are arranged opposite to each other;

[0017] The water control and sand discharge mechanism also includes two batteries, one battery is connected to a cation gathering plate to provide cations for the cation gathering plate.

[0018] Furthermore, the water drainage, water control and sand discharge mechanisms are distributed at intervals in the flow direction of the sedimentator.

[0019] Furthermore, signal receivers are arranged at intervals in the length direction of the screen pipe, and the signal receivers are used to receive control signals. After receiving the signals, the signal receivers are uniformly processed by the screen pipe signal controller to control the operation of batteries in different areas and different water control and sand discharge mechanisms.

[0020] Further, the screen pipe is sleeved inside the casing pipe; the system further includes a control capsule for carrying a control signal into the interval where the screen pipe is located.

[0021] Further, the horizontal well water control and sand discharging system further includes a control capsule storage chamber, an injection liquid storage chamber, a mixing skid, an injection pump, an injection pipeline, a coiled tubing, and a derrick;

[0022] The control capsule storage chamber is used for storing control capsules;

[0023] The injection liquid storage chamber is used for storing liquid;

[0024] The mixing skid is used for putting the control capsule into the injection liquid so that it can be carried by the injection liquid and then pumped into the coiled tubing through the injection pump via the injection pipeline. The coiled tubing is placed into the casing pipe through the derrick, and the control capsule enters the screen pipe through the inner annulus of the coiled tubing and emits a control signal.

[0025] Further, the control capsule includes a signal releaser, a signal controller, a battery, and a capsule layer; the capsule layer is used for encapsulating the signal releaser, the signal controller, and the battery; the signal releaser releases the control signal in the form of an electromagnetic signal or an acoustic signal; the signal controller writes control information in a coded manner.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] First, the prior art mainly develops oil and water control mechanisms based on the property differences between oil and water. The present invention innovatively uses the methods of swirl sand settling and cation aggregation to control water and sand in different time periods and layers, achieving the control of gas, water, and sand in different production cycles, reasonably adjusting the height of edge and bottom water, real-time adjusting the liquid production profile of the horizontal well, realizing the whole-life production water and sand control of restricting production in the medium term and discharging sand in the later stage, ensuring the smoothness of the gas production channel in the near-well zone, maximizing the tapping of production capacity, and ensuring the stable production period.

[0028] Second, the prior art is mainly applied to conventional oilfields and cannot play a role in emerging resources, especially natural gas hydrate resources and muddy water natural gas resources. The structural innovation of the present invention will be mainly applied to the horizontal well exploitation process of natural gas hydrate resources and muddy sand natural gas resources, and can achieve multiple effects of gas production, water control, and sand discharging, maximizing the extension of the high-efficiency stable production period. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the applicable process of the horizontal well water control and sand discharging system provided by the embodiment of the present invention;

[0030] Figure 2Schematic diagram of the internal structure of the screen pipe;

[0031] Figure 3 Schematic diagram of the water control and sand drainage mechanism inside the screen pipe;

[0032] Figure 4 Schematic diagram of the structure of the control capsule;

[0033] In the figure: 1. Control capsule storage chamber; 2. Injection liquid storage chamber; 3. Formation; 4. Signal receiver; 5. Screen pipe; 6. Control capsule; 7. Coiled tubing; 8. Casing; 9. Derrick; 10. Injection pipeline; 11. Injection pump; 12. Mixing skid; 13. Formation produced water and sediment; 14. Lower joint of the screen pipe; 15. Production port; 16. Outer base pipe; 17. Sand control medium; 18. Inner base pipe; 19. Upper joint of the screen pipe; 20. Annular channel; 21. Water control and sand drainage mechanism; 22. Storage battery; 23. Cation aggregation plate; 24. Transmission line; 25. Screen pipe signal controller; 26. Precipitator; 61. Signal release device; 62. Signal controller; 63. Battery; 64. Capsule layer. Detailed implementation manners

[0034] Embodiment:

[0035] The technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0036] When developing high-silt gas reservoirs and hydrate reservoirs, the casing 8 in the formation 3 provides a stable wellbore structure. Under normal circumstances, the wellbore structure extends horizontally as a horizontal well. Since the water decomposed from hydrates, gases, etc. will carry the formation produced water and sand into the near-wellbore zone, due to the limitations of the pore structure and sand drainage capacity, after the sediment bridges and accumulates in the micropores, a composite blockage of water blockage - sand blockage is caused, resulting in a significant reduction in the gas-phase permeability of the original channel and a decrease in productivity. In addition, during the decomposition process of hydrates, the main substances entering the wellbore include: methane gas, decomposed water and original pore water, and formation sediment particles, mainly these three substances. Among them, the gas migration resistance is small and the requirement for permeability is low. However, as the exploitation progresses, the produced water rates faced by different horizontal sections are different. If water control is not carried out, the pore structure around the wellbore will be flooded in a short period, and the water lock effect of the microscopic pore structure is obvious, which will affect the gas production.

[0037] Therefore, during different exploitation periods, water control and sand drainage operations should be carried out in combination with the problem of edge-bottom water ridge advancement, so as to adjust the liquid production profile balance and extend the stable production period.

[0038] Based on this, the present invention innovatively utilizes the methods of swirl sand settling and cation aggregation to control water and sand with greater difficulty in a time - segmented and layer - positioned manner, achieving the control of gas, water, and sand in different production cycles, reasonably adjusting the height of edge and bottom water, real - time adjusting the liquid production profile of horizontal wells, realizing the whole - life control of liquid and sand production with restricted flow in the middle period and sand discharge in the later period, ensuring the smoothness of the gas - producing channel near the wellbore, maximizing the excavation of production capacity, and ensuring the stable production period.

[0039] Specifically, referring to Figure 1 As shown, this embodiment shows a schematic diagram of the overall effect of the horizontal well water control and sand discharge system and surface supporting facilities during construction. The surface supporting mainly includes a control capsule storage room 1, an injection liquid storage room 2, a mixing skid 12, an injection pump 11, an injection pipeline 10, and a derrick 9, etc. The control capsule storage room 1 is a reservoir for the control capsule 6, used to store the control capsule 6. The storage room has special requirements for humidity and temperature to ensure the stability of the control capsule in the storage room. The injection liquid storage room 2 carries the liquid for the control capsule 6 to enter the wellbore, which can be completion fluid, sand control fluid, etc. The mixing skid 12 puts the control capsule 6 into the injection liquid so that it can be carried by the injection liquid and then pumped into the coiled tubing 7 through the injection pump 11. The coiled tubing 7 is a flexible - tube - like structure and is placed into the well through the derrick 9. The control capsule 6 enters the wellbore through the inner annulus of the coiled tubing 7 and emits a control signal.

[0040] During the exploitation of resources such as natural gas, shale gas, and hydrates, formation - produced water and sediment 13 often appear, causing blockage of the production channel and water flooding, etc., seriously affecting production. Therefore, different methods need to be adopted in different stages. For this reason, in this embodiment, a screen pipe 5 is provided in the casing. The screen pipe 5 includes an outer base pipe 16 and an inner base pipe 18. An annulus channel 20 is formed between the outer base pipe 16 and the inner base pipe 18. The outer base pipe 16 and the inner base pipe 18 are generally made of steel structure to improve the overall structural strength of the screen pipe 5. A sand - retaining medium 17 is also provided in the outer base pipe 16, which is generally of types such as gravel packing, wire - wound, slotted, metal wool, foam pores, etc., playing a partial sand - control role. The two ends of each section of the screen pipe 5 are respectively thread - connected with a screen pipe lower joint 14 and a screen pipe upper joint 19. The screen pipe lower joint 14 is generally a male thread, and the screen pipe upper joint 19 corresponds to the screen pipe lower joint 14 and is generally a female thread to facilitate the splicing of multiple sections of the screen pipe 5. A production port 15 is provided at the end of the annulus channel 20. The gas, liquid, and sediment entering the inside of the screen pipe 5 all enter the inside of the wellbore through the production port 15 and are then transported to the surface for gathering and utilization. Figure 2It can be seen that the annulus channel 20 is divided into two sections, namely the first annulus channel section opposite to the sand control medium and the second annulus channel section for installing the sedimentation device 26 and the water control and sand discharge mechanism 21; a convergence port is formed at the junction of the first annulus channel section and the second annulus channel section, and the starting end of the sedimentation device 26 is connected to the convergence port. The sedimentation device 26 is a spiral sedimentation device, which sorts the water and sediment entering this area in a spiral manner. Since the sediment contains clay and the density of clay is 2.2~2.4 g / cm 3 , and the density of water is 1.0 g / cm 3 . Under the condition of a relatively low flow rate, under the action of gravity, the clay and sediment will settle slowly. However, due to the relatively fine particle size of the clay particles, generally the particle size of the clay particles after entering the screen tube is generally <40μm. Therefore, once the water flow speeds up, the clay particles are easily carried by the water. Therefore, when the flow rate is relatively low, after the muddy water passes through this section, sand will be deposited in the area with a larger curvature, and the produced water will be obtained.

[0041] In addition, since clay is mainly composed of silicates, carbonate rocks, etc., its particles are negatively charged as a whole, mainly due to: ① isomorphous substitution in the clay lattice, where Si (tetravalent) is replaced by aluminum (trivalent) in some silicon-oxygen tetrahedra, and aluminum (trivalent) is replaced by magnesium and iron (divalent) in some aluminum-oxygen octahedra, thereby generating residual negative charges. ② It can also be generated by the dissociation of carboxyl groups contained in some humus on the seabed, dissociating H+ to generate negative charges. After the H+ on the carboxyl group is dissociated, the carboxyl group becomes a negatively charged ion group. ③ As the pH value changes, an alkaline environment is conducive to the dissociation of H+ to generate more negative charges. The pH value of the pore water in the South China Sea hydrate reservoir known to date is generally between 7 and 9, which is weakly alkaline, which is conducive to the clay showing a strong negative charge, that is, anionic charge. Clay is easily attracted and aggregated by positive charges under the action of an external electric field, while reservoir water does not exhibit positive and negative charge adsorption characteristics. Therefore, the present invention will utilize the density and charge differences between water and clay to achieve the purpose of controlling water and draining sand. In this embodiment, the following scheme is specifically adopted. The water control and sand discharge mechanism 21 is distributed in the sedimentation tank 26 at intervals along the direction of fluid flow. The water control and sand discharge mechanism 21 includes two storage batteries 22 and two cation gathering plates 23. The two cation gathering plates 23 are arranged opposite to each other, and one storage battery 22 is connected to one cation gathering plate 23; the cation gathering plate 23 is a metal structure that can gather cations released by the storage battery 22, and the anions are evenly dispersed into the screen tube 5 by grounding. In this way, when the storage battery 22 is discharged, the anions are grounded and dissipated, and the cations are gathered on the water control and sand discharge mechanism 21 to form the cation gathering plates 23. At this time, the water and mud and sand passing through the area generally carry anions, which will be adsorbed by the water control and sand discharge mechanism 21 and gradually gathered, so the water flow channel will gradually decrease, and the water volume will decrease accordingly. When the cation aggregation plate 23 stops releasing cations, the mud and sand lose their adhesion and are uniformly discharged from the wellbore. The flow rate in the spiral sedimentator 26 will also increase, thereby discharging the sedimented mud and sand inside, achieving the purpose of slow or full discharge of mud and sand, and further achieving the purpose of controlling water and discharging sand.

[0042] Specifically, signal receivers 4 are arranged at intervals in the length direction of the screen tube 5, and the signal receivers 4 are connected together through a transmission line 24. After the signal receivers 4 receive the signal, the screen tube signal controller 5 processes it uniformly to control the operation of the storage batteries of different water control and sand discharge mechanisms 21 in different regions.

[0043] like Figure 4As shown in the figure, the control capsule 6 includes a signal releaser 62, a signal controller 61, a battery 63, and a capsule layer 64. The capsule layer 64 is used to encapsulate the signal releaser 61, the signal controller 62, and the battery 63 to prevent damage during the process of being carried into the wellbore by the fluid. The capsule layer 64 can be made of materials that do not shield electromagnetic signals, acoustic signals, etc., and do not react with the carrying fluid. For example, it can be made of polymer, rubber, resin materials, etc. The signal releaser 61 releases control signals in the form of electromagnetic signals or acoustic signals, including information such as whether to discharge the storage battery 22 of the water control and sand discharge mechanism 21 in different regions, the discharge duration, and the discharge power. The signal controller 62 writes control information in an encoded manner. After entering the wellbore, it continuously controls the signal releaser to release signals.

[0044] The following further illustrates the horizontal well water control and sand discharge system with an example of an application scenario:

[0045] Taking the exploitation of a natural gas hydrate horizontal well as an example, different degrees of control over water production and sand production are required in different production cycles, which specifically include the following steps:

[0046] First, the water control and sand discharge screen pipe 5 is connected into a sand control section through the lower screen pipe joint 14 and the upper screen pipe joint 19, and is placed inside the casing 8 by using the derrick 9 and stopped after entering the production formation. It plays a preliminary role in sand control.

[0047] Second, in the initial stage of exploitation, the bottom hole pressure is relatively high, and the flow forces of gas, water, sand, etc. are strong. To promote the release of the production capacity channel, appropriate discharge is generally selected. At this time, the injection of the control capsule is not required, and the water control and sand discharge mechanism is in an inoperative state. The gas, water, and sand entering the screen pipe then enter the wellbore through the production port 15 and are produced to the ground for collection.

[0048] III. During the middle stage of production, the water production generally decreases. Based on the production data parameters in the well, the water production and sand production conditions of different intervals can be judged. The edge-bottom water encroachment is severe in some intervals, and there is a risk of water flooding. The amount of sediment transported to the vicinity of the wellbore begins to increase. Therefore, in order to ensure the continuous gas production, water control and sand removal operations are required. Through computer processing technology on the ground, control signals are input into the control capsule 6. The control signals include information such as the opening of the water control and sand removal mechanism 21 in the bottom water encroachment section, the discharge duration of the storage battery 22, and the discharge power, etc.; the control capsule 6 and the injection liquid are mixed by the mixing skid 12 and enter the injection pump 11. The injection pump 11 provides pumping hydraulic force and is pumped into the bottom of the well through the injection pipeline 10, the derrick 9, and the coiled tubing 7. During the process of the control capsule 6 moving from the root end to the toe end of the wellbore, the signal receivers 4 at different positions will receive the control signals sent by the control capsule 6 and transmit them to the screen pipe signal controller 25. The screen pipe signal controller 25 controls the storage battery 22 to start discharging. After the storage battery 22 discharges, the anions are dissipated through grounding, and the cations accumulate on the water control and sand removal mechanism 21 to form a cation accumulation plate 23. At this time, for the water and sediment passing through this area, the sediment generally carries anions and will be adsorbed by the water control and sand removal mechanism 21 and gradually accumulates, then the water flow channel will gradually decrease and the water volume will decrease accordingly.

[0049] After the water volume decreases, the flow rate of the sediment-containing liquid in the spiral settler 26 decreases, and the sediment has sufficient time to undergo a precipitation reaction. The precipitated sediment will also reduce the flow space of the spiral settler 26, increasing the flowing pressure of the produced water and reducing the water production volume, achieving the purpose of water control. The edge-bottom water encroachment in this area is alleviated, and the water layers in other production intervals will follow up in due course, and the entire produced water profile tends to be balanced. During the whole process, gas production can proceed normally.

[0050] IV. In the late stage of production, the gas release decreases and the production capacity declines. The overall edge-bottom water encroachment in the horizontal section reaches a position relatively close to the wellbore. In order to fully exploit the production capacity, the last part of the gas needs to be discharged from the wellbore. Therefore, the working duration and working power of the water control and sand removal mechanism 21 need to be reduced or shut down. Then, the control capsule 6 carrying control information is pumped into the bottom of the well through the coiled tubing 7. After repeating step II, the water control and sand removal mechanism 21 starts to respond, and the cation accumulation plate stops power supply or reduces the power supply power. Then the sediment loses its adsorption force, starts to decompose and is transported with the water flow. The production capacity channel is gradually released, the water flow increases, the flow rate of the liquid in the spiral settler 26 increases, and the sediment is also carried into the wellbore. The water-containing profile displaces the gas reservoir around the wellbore to the wellbore, completing the gas production in the last stage.

[0051] V. At the end of production, the minerals in the formation are exhausted. The derrick 9 is used to fill the casing 8 with abandonment well cement, and the entire production well is abandoned, ending the production. The derrick 9 is moved to the next production well and the production is repeated.

[0052] In summary, compared with the prior art, the present invention has the following technical advantages:

[0053] 1. The prior art mainly developed oil and water control mechanisms based on the property differences between oil and water. The present invention innovatively uses the methods of cyclone sand settling and cation aggregation to control water and sand in different time periods and stratigraphic positions with greater difficulty, achieving the control of gas, water, and sand in different production cycles, reasonably adjusting the height of edge and bottom water, real-time adjusting the liquid production profile of horizontal wells, realizing the full-life production and sand control of restricting production in the medium term and discharging sand in the later stage, ensuring the smoothness of the gas production channel in the near-well zone, maximizing the tapping of production capacity, and ensuring the stable production period.

[0054] 2. The prior art is mainly applied to conventional oil fields and cannot play a role in emerging resources, especially natural gas hydrate resources and muddy water-containing natural gas resources. The structural innovation of the present invention will be mainly applied to the horizontal well exploitation process of natural gas hydrate resources and muddy sand-containing natural gas resources, and can achieve multiple effects of gas production, water control, and sand discharge, maximizing the extension of the high-efficiency stable production period.

[0055] The above embodiments are only used to illustrate the technical concept and characteristics of the present invention, and the purpose is to enable those of ordinary skill in the art to understand the content of the present invention and implement it accordingly, and cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the essence of the content of the present invention should be covered within the protection scope of the present invention.

Claims

1. A horizontal well water control and sand discharging system, characterized in that Comprising: A screen pipe, the fluid after passing through the screen pipe enters a sedimentation tank, and the sedimentation tank is used for sedimenting the sediment in the fluid; A water control and sand discharge mechanism, including a cation aggregation plate, when the cation aggregation plate is electrified, it is used to adsorb the sediment flowing through the sedimentation tank; The cation aggregation plate is made of metal, there are two pieces and they are arranged opposite to each other; the sedimentation tank is spiral, used for sorting the water and sediment entering the sedimentation tank; The water control and sand discharge mechanism further includes two batteries, one battery is correspondingly connected to one cation aggregation plate, used to provide cations for the cation aggregation plate; The water control and sand discharge mechanism is distributed at intervals in the flow direction of the sedimentation tank; Signal receivers are arranged at intervals in the length direction of the screen pipe, the signal receivers are used to receive control signals, and after the signal receivers receive the signals, they are uniformly processed by the screen pipe signal controller to control the operation of the batteries of different water control and sand discharge mechanisms in different areas; 2. The horizontal well water control and sand discharging system according to claim 1, wherein The screen pipe includes an outer base pipe and an inner base pipe arranged inside the outer base pipe, and an annulus channel is formed between the inner base pipe and the outer base pipe; a sand blocking medium is arranged in a partial area of the outer base pipe; the annulus channel is divided into two sections, namely a first annulus channel section opposite to the sand blocking medium and a second annulus channel section for installing the sedimentation tank and the water control and sand discharge mechanism; a converging port is formed at the junction of the first annulus channel section and the second annulus channel section, and the starting end of the sedimentation tank is communicated with the converging port.

3. The horizontal well water control and sand drainage system according to claim 1, characterized in that The screen pipe is sleeved inside a casing; The system further includes a control capsule, used to carry a control signal into the interval where the screen pipe is located.

4. The horizontal well water control and sand drainage system according to claim 3, wherein The system further includes a control capsule storage room, an injection liquid storage room, a mixing skid, an injection pump, an injection pipeline, a coiled tubing and a derrick; The control capsule storage room is used to store control capsules; The injection liquid storage room is used to store liquids; The mixing skid is used to put the control capsule into the injection liquid so that it can be carried by the injection liquid and then pumped into the coiled tubing through the injection pump via the injection pipeline. The coiled tubing is placed into the casing through the derrick, and the control capsule enters the screen pipe through the annulus inside the coiled tubing and emits a control signal.

5. The horizontal well water control and sand drainage system according to claim 3 or 4, characterized in that The control capsule includes a signal release device, a signal controller, a battery and a capsule layer; the capsule layer is used to encapsulate the signal release device, the signal controller and the battery; the signal release device releases the control signal in the form of an electromagnetic signal or an acoustic signal; the signal controller writes control information in a coded manner.

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