Hydrate mining method and device for artificially inducing regional sedimentation to transform reservoir

Abstract

The present invention discloses a method and device for hydrate extraction by artificially inducing regional settlement to transform a reservoir. The method includes drilling a production-increasing well in the lower disturbance zone, constructing several horizontal branch wells in the lower zone of a production well, drilling a production well in the well construction and production zone, and constructing a production well in the middle of a hydrate reservoir. After completing the engineering construction phase, a production tubing is lowered into the production well to extract hydrates. The gas-liquid-solid mixture obtained by extraction is lifted to an offshore extraction platform, and after separation and treatment in a gas-liquid-solid separation and storage device, pure natural gas is extracted for storage and transport to a utilization site. This extraction method utilizes the creep and settlement phenomenon of the formation in the extraction process of a weakly consolidated hydrate reservoir through well location design. Through rationally designed engineering implementation and settlement control, complex formation communication fractures are formed, achieving large-scale storage-transformation communication of the hydrate reservoir, and forming an effective, economical, and high-yield hydrate extraction method.

Description

Technical Field

[0001] The present invention relates to the technical field of natural gas hydrate production equipment, and in particular to a hydrate production method and device for artificially inducing regional sedimentation to transform a reservoir. Background Art

[0002] my country has completed two rounds of natural gas hydrate pilot production projects, validating the feasibility of these projects. The country is currently in the process of transitioning to productive development, accelerating industrialization, increasing production capacity, reducing production costs, and truly realizing the industrial application of natural gas hydrates. The pressure reduction method employed in the first two rounds of pilot production still faces key challenges, including high production costs, rapid production decline, and difficulty maintaining stable and high production, in response to the demands of industrial application. Most natural gas hydrate reservoirs are low-permeability, unconsolidated muddy silt sand natural gas hydrate reservoirs, characterized by low permeability and prone to creep deformation. While hydraulic fracturing methods commonly used in the oil and gas industry are feasible for reservoir reconstruction, the resulting channels are difficult to maintain. Furthermore, the depth and breadth of the reconstruction are limited by the level of engineering technology, making it difficult to establish effective high-permeability reservoir diversion channels. Summary of the Invention

[0003] The purpose of the present invention is to overcome the deficiencies of the prior art and to provide a method and apparatus for hydrate production by artificially inducing regional sedimentation to transform a reservoir.

[0004] The present invention is achieved through the following technical solution: a hydrate production method for artificially inducing regional sedimentation to transform a reservoir, comprising the following steps:

[0005] Step 1: Select a suitable natural gas hydrate reservoir as the mining target, build an offshore mining platform in the offshore area, place the drilling equipment and casing required for drilling and well construction on the offshore mining platform, and place the gas storage tanks, gas-liquid-solid separation storage equipment, pumping material storage equipment and liquid storage heating equipment required for mining the hydrate reservoir; the hydrate reservoir includes the upper overburden, the upper reservoir area, the well construction and production area, the lower disturbance area and the lower overburden from top to bottom; build a production well for hydrate mining, the production well passes through the seawater area, the upper overburden, the upper reservoir area and the well construction and production area from top to bottom, and the production well includes a production vertical section and a production horizontal section connected to it; build a production stimulation well below the production well in the well construction and production area;

[0006] Step 2: Drilling of stimulation wells in the lower disturbance zone and construction of several horizontal branch wells in the lower zone of the production well;

[0007] Step 3: Drilling a production well in the well construction and production area. Build a horizontal production section in the middle of the hydrate reservoir. Connect the horizontal section to the vertical production section and extend it upward to the offshore production platform. After drilling the production well, run a production well cementing casing. A production well cement sheath is built on the outside of the casing. During production, run a production string inside the production well cementing casing.

[0008] Step 4: Perform reservoir stimulation in the production well construction area. Run a coiled tubing equipped with hydraulic perforating and pumping equipment, extract hot seawater from the liquid storage and heating equipment, and perform hydraulic jetting. This forms penetrating hydraulic jet holes in the production well cementing casing and cement sheath. Ethylene glycol and curing resin are then injected into the hydraulic jet holes using a pumping material storage device. The liquid ejected from the hydraulic jet holes forms a high-conductivity channel, which connects the production well to the stimulation well.

[0009] Step 5: After completing the construction phase, a production tubing string is lowered into the production well to extract hydrates. The gas-liquid-solid mixture obtained from the extraction is lifted to the offshore production platform. After separation and treatment by the gas-liquid-solid separation and storage equipment, pure natural gas is extracted for storage and transportation to the application site.

[0010] A hydrate production device for artificially inducing regional sedimentation to transform a reservoir, comprising an offshore production platform, a gas storage tank, a gas-liquid-solid separation storage device connected to the gas storage tank, a pumping material storage device, a storage liquid heating device, a production well and a production-increasing well; the offshore production platform is built in an offshore area where a natural gas hydrate reservoir has been explored; the hydrate reservoir comprises, from top to bottom, an upper covering layer, an upper reservoir area, a well construction and production area, a lower disturbance area and a lower covering layer; the production-increasing well is built in the lower disturbance area, the production-increasing well comprises a vertical section and a horizontal section connected thereto, the horizontal section is provided with a number of horizontal branch wells, the horizontal branch wells are built in the lower disturbance area; a production well for hydrate production is built, the production well passes through four areas, namely, a seawater area, an upper covering layer, an upper reservoir area and a well construction and production area, from top to bottom, the production well comprises A production vertical section and a production horizontal section connected thereto; the production horizontal section is constructed in the middle of the hydrate reservoir and is located above the production stimulation well, and the production vertical section extends upward to the offshore mining platform; the production well includes, from the outside to the inside, a production well cement sheath, a production well cementing casing and a production well production string; in the reservoir transformation process, a continuous oil pipe equipped with a hydraulic perforating and pumping device is lowered, and hot seawater in the liquid storage and heating device is extracted for hydraulic injection, forming penetrating hydraulic jet holes on the production well cementing casing and the production well cement sheath; the pumping material storage device injects ethylene glycol and curing resin into the hydraulic jet holes, and the liquid ejected from the hydraulic jet holes forms a high-conductivity channel, which connects the production well with the production stimulation well; the production well is respectively connected to the gas-liquid-solid separation storage device, the pumping material storage device and the liquid storage and heating device.

[0011] The stimulation well is filled with sand particles, the diameter of which is not less than 10 to 20 times the particle diameter of the reservoir sand particles in the hydrate reservoir.

[0012] Several of the horizontal branch wells are located on the same layer parallel to the production horizontal section and are distributed in a comb-tooth shape; or, several of the horizontal branch wells are distributed in a fishbone shape at intervals and extend in multiple directions.

[0013] Several of the horizontal branch wells are located in different layers; or, among the several horizontal branch wells, some of the horizontal branch wells are located in the same layer, and the other part of the horizontal branch wells are located in different layers.

[0014] The production string of the production well is equipped with a sand control screen, which is located at the production horizontal section after being installed and lowered; the sand control screen is filled with gravel.

[0015] The particle size of the gravel is 6 to 10 times the particle size of the reservoir particles in the well production area or the lower disturbance area.

[0016] Compared with the existing technology, the advantages of the present invention are: this mining method and device adopts a double-layer multi-branch horizontal well construction method, in which the upper horizontal well serves as a natural gas hydrate production well for hydrate mining; the lower multi-branch horizontal well serves as a stimulation well for natural gas hydrate reservoir transformation, and is used to transform the hydrate reservoir. This mining method aims to achieve large-scale regional reservoir disturbance of the natural gas hydrate reservoir through the construction of multiple multi-directional stimulation wells, inducing regional formation subsidence, thereby changing the original stability conditions of the reservoir, generating complex microcracks, and increasing the seepage capacity of the formation. Moreover, as the depressurization mining time of natural gas hydrate increases, the formation hydrates continue to decompose, resulting in a decrease in the mechanical strength of the formation around the wellbore, the sediments continue to sink and compact, and formation voids gradually form around the production wellbore. The stability of the hydrate-containing formation above the reservoir changes, and formation subsidence also occurs, forming new communication channels to expand the mining range. This mining method uses reasonable theoretical analysis and well location design, takes advantage of the formation creep and settlement phenomenon that occurs during the mining process of weakly consolidated hydrate reservoirs, and through well-designed engineering implementation and settlement control, forms complex formation communication fractures, achieves large-scale storage-transformation communication in the hydrate reservoir, and forms an effective, economical and high-yield hydrate mining method. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the structure of an embodiment of the present invention;

[0018] Figure 2 for Figure 1 A magnified view of the local structure on the middle left;

[0019] Figure 3 Schematic diagram of the structural details of the hydraulic jet according to an embodiment of the present invention;

[0020] Figure 4 This is a structural schematic diagram of a comb-shaped distribution of horizontal branch wells according to an embodiment of the present invention;

[0021] Figure 5 This is a schematic diagram of the structure of the horizontal branch wells in a fishbone-shaped distribution according to an embodiment of the present invention;

[0022] Figure 6 This is a structural schematic diagram of an irregularly distributed horizontal branch well in an embodiment of the present invention.

[0023] The meanings of the reference numerals in the figure are: 1. Offshore mining platform; 2. Gas storage tank; 3. Gas-liquid-solid separation storage equipment; 4. Pumping material storage equipment; 5. Liquid storage heating equipment; 6. Production tubing for production wells; 7. Cementing casing for production wells; 8. Cement ring for production wells; 9. Stimulation wells; 10. Hydraulic jet holes; 11. High conductivity channel; 12. Gravel; a. Seawater area; b. Upper overburden; c. Upper reservoir area; d. Well construction and production area; e. Lower disturbance area; f. Lower overburden. DETAILED DESCRIPTION

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] Example

[0026] See Figures 1 to 6 , is a hydrate production method for artificially inducing regional sedimentation to transform the reservoir, comprising the following steps:

[0027] Step 1: Select a suitable natural gas hydrate reservoir as the mining target, build an offshore mining platform 1 in the offshore area, place drilling equipment and casing required for drilling and well construction on the offshore mining platform 1, and place gas storage tanks 2, gas-liquid-solid separation storage equipment 3, pumping material storage equipment 4 and liquid storage heating equipment 5 required for mining the hydrate reservoir; the hydrate reservoir includes, from top to bottom, the upper cover layer b, the upper reservoir area c, the well construction and production area d, the lower disturbance area e and the lower cover layer f; build a production well for hydrate mining in the seawater area a, and the production well passes through the seawater area a, the upper cover layer b, the upper reservoir area c and the well construction and production area d from top to bottom. The production well includes a production vertical section and a production horizontal section connected to it; build a production stimulation well 9 below the production well in the well construction and production area d;

[0028] Step 2: Drilling a stimulation well 9 in the lower disturbance zone e, and constructing several horizontal branch wells in the lower zone of the production well. The construction of several horizontal branch wells is to first disturb the original stable formation of the hydrate reservoir, disturb the mechanical properties of the formation, weaken the reservoir strength, form reconstructed reservoir communication fractures, promote hydrate decomposition, and connect the reservoir.

[0029] Step 3: Drilling a production well in the well construction production area d. A production horizontal section is constructed in the middle of the hydrate reservoir. A production vertical section connected to the production horizontal section extends upward to the offshore production platform 1. After the production well is drilled, a production well cementing casing 7 is lowered into the production well. A production well cement sheath 8 is built on the outside of the casing. During production, a production string 6 is inserted into the production well cementing casing 7. The installation of the production well cementing casing 7 can strengthen the wellbore strength of the production well and ensure that the wellbore will not deform and affect the production channel during formation settlement.

[0030] Step 4: Performing a reservoir stimulation process for the production well in the well construction production area d, running a coiled tubing equipped with a hydraulic perforating pumping device 4, extracting hot seawater from the liquid storage and heating device 5 for hydraulic injection, and forming penetrating hydraulic jet holes 10 in the production well cementing casing 7 and the production well cement sheath 8. Ethylene glycol and curing resin are then injected into the hydraulic jet holes 10 by the pumping material storage device 4. The liquid ejected from the hydraulic jet holes 10 forms a high-conductivity channel 11, which connects the production well to the stimulation well 9.

[0031] Step 5: After completing the construction phase, a production string 6 is lowered into the production well to extract hydrates. The gas-liquid-solid mixture obtained from the extraction is lifted to the offshore production platform 1. After separation treatment in the gas-liquid-solid separation and storage equipment 3, pure natural gas is extracted for storage and transportation to the application site.

[0032] A hydrate production device for artificially inducing regional sedimentation to transform a reservoir comprises an offshore production platform 1, a gas storage tank 2, a gas-liquid-solid separation storage device 3 connected to the gas storage tank 2, a pumping material storage device 4, a storage liquid heating device 5, a production well and a production stimulation well 9; the offshore production platform 1 is constructed in an offshore area where a natural gas hydrate reservoir has been explored; the hydrate reservoir comprises, from top to bottom, an upper cover layer b, an upper reservoir area c, a well construction and production area d, a lower disturbance area e and a lower cover layer f; the production stimulation well 9 is constructed in the lower disturbance area e, and the production stimulation well 9 comprises a vertical section and a horizontal section connected thereto, the horizontal section is provided with a number of horizontal branch wells, and the horizontal branch wells are constructed in the lower disturbance area e; a production well for hydrate production is constructed, and the production well passes through four areas, namely, a seawater area a, an upper cover layer b, an upper reservoir area c and a well construction and production area d, from top to bottom. It includes a production vertical section and a production horizontal section connected to it; the production horizontal section is built in the middle of the hydrate reservoir and is located above the production stimulation well 9, and the production vertical section extends upward to the offshore production platform 1; the production well includes a production well cement ring 8, a production well cementing casing 7 and a production well production string 6 from the outside to the inside. During the reservoir transformation process, a continuous oil pipe equipped with a hydraulic perforating and pumping device is lowered, and hot seawater in the liquid storage and heating device 5 is extracted for hydraulic injection, forming a penetrating hydraulic jet hole 10 on the production well cementing casing 7 and the production well cement ring 8; the pumping material storage device 4 injects ethylene glycol and curing resin into the hydraulic jet hole 10, and the liquid ejected from the hydraulic jet hole 10 forms a high-conductivity channel 11, which connects the production well with the production stimulation well 9; the production well is connected to the gas-liquid-solid separation storage device 3, the pumping material storage device 4, and the liquid storage and heating device 5 respectively. In this embodiment, the hydraulic perforation and pumping equipment is existing equipment, and its specific structure is not shown (nor in the accompanying drawings). The hydraulic perforation and pumping equipment is installed during the reservoir transformation process. The hydraulic perforation and pumping equipment is lowered into the production well via continuous tubing and is installed to perform hydraulic perforation and pumping measures during the reservoir transformation process. After the reservoir transformation process is completed, the hydraulic perforation and pumping equipment needs to be removed. In this embodiment, the liquid separation outlet of the gas-liquid-solid separation storage device 3, as well as the outlets of the pumped material storage device 4 and the liquid storage and heating device 5 are all connected to the inlet of the production well. The outlet of the production well is connected to the inlet of the gas-liquid-solid separation storage device 3. The gas separation outlet of the gas-liquid-solid separation storage device 3 is connected to the gas storage tank 2. The bottom of the gas-liquid-solid separation storage device 3 also has a solid separation outlet (not shown). The solid separation outlet only discharges reservoir sand, which can be recycled or discharged back to the seabed mud surface. The inlet of the liquid storage and heating device 5 is connected to seawater via a pipeline and a water pump. Figure 1 and Figure 2 In the figure, the arrow points to the direction of migration.

[0033] Stimulation well 9 is filled with sand particles, the diameter of which is no less than 10 to 20 times the particle size of the reservoir sand particles in the hydrate reservoir. In this embodiment, the large-diameter sand particles are filled in stimulation well 9 after well construction. On the one hand, this increases the permeability of the formation and establishes a rapid channel for hydrate decomposition and circulation. On the other hand, it regulates the path of formation subsidence. It can be seen that formation subsidence has occurred around the wellbore. The complex connecting fractures formed after subsidence achieve large-scale reservoir communication and promote circulation through the high-permeability rapid channel. In this embodiment, the upper reservoir area c, the well construction and production area d, and the lower disturbance area e are all hydrate reservoirs. The size of the reservoir sand particles in the hydrate reservoir is basically the same. Therefore, the diameter of the sand particles filled in stimulation well 9 is selected to be no less than 10 to 20 times the particle size of the reservoir sand particles in the hydrate reservoir.

[0034] In this embodiment, the drilling process of the production-increasing well 9 is carried out first. After the horizontal branch well is built in the horizontal section of the production-increasing well 9, the production-increasing well 9 is filled with sand. After the vertical section of the production-increasing well 9 that does not overlap with the production well is filled with sand, a production well is constructed on the basis of the vertical section of the production-increasing well 9. There is partial overlap between the production vertical section of the production well and the vertical section of the production-increasing well 9 (the overlapping part is the part shared by the two).

[0035] Several horizontal branch wells are located in the same layer parallel to the production horizontal section and arranged in a comb-tooth pattern; alternatively, several horizontal branch wells are spaced apart and extend in multiple directions in a fishbone pattern. In this embodiment, the structure of the stimulation wells 9 of the horizontal branch wells can be designed according to actual project requirements. The specific structure can be a comb-tooth pattern, a fishbone pattern, an irregular pattern based on the distribution of reservoir hydrates, or other stimulation well 9 distribution patterns that meet construction safety and project design requirements.

[0036] Several horizontal branch wells are located in different layers; or, among several horizontal branch wells, some are located in the same layer and others are located in different layers. The multiple horizontal branch wells of the stimulation well 9 can be designed to be located in the same layer or in multiple layers according to the actual project requirements.

[0037] The production string 6 of the production well is equipped with a sand screen, which is located in the production horizontal section after installation and is filled with gravel 12. The setting of the sand screen takes production efficiency into consideration and performs reasonable and appropriate sand control according to the designed sand control mesh size.

[0038] The particle size of the gravel 12 is 6 to 10 times that of the reservoir particles in the well production area d or the lower disturbance area e. The sand control effect of the gravel 12 hinders and slows down the time and amount of reservoir particles entering the production well.

[0039] In this embodiment, the spacing between the production well and the stimulation well 9 is determined based on the actual engineering design. It is necessary to ensure that the reservoir-renovation measures can communicate with the stimulation well 9 while ensuring the safety of well construction. During the hydraulic jetting process of the hydraulic perforating and pumping equipment to break up the hydrates, chemical materials such as ethylene glycol and curing resin can be injected simultaneously to accelerate the decomposition of some hydrates and inhibit their secondary formation, thus forming a stable, highly conductive channel 11 connecting the production well and the stimulation well 9, further replenishing formation heat.

[0040] This embodiment adopts a double-layer multi-branch horizontal well construction method, in which the upper layer is the upper production horizontal well, and the lower layer is the lower horizontal branch well of the production-increasing well 9; the upper production horizontal well serves as a production well for natural gas hydrates, and is used for hydrate exploitation; the lower multi-branch horizontal well of the production-increasing well 9 serves as a production-increasing well 9 for the transformation of the natural gas hydrate reservoir, and is used for the transformation of the hydrate reservoir. This mining method aims to achieve large-scale regional reservoir disturbance of the natural gas hydrate reservoir by constructing a large number of multi-directional production-increasing wells 9 and using hydraulic jets to create a large number of irregular caves in the production-increasing wells 9, thereby inducing changes in the original stable conditions of the reservoir. When using the depressurization method to mine hydrates, as the pressure in the production well decreases and is transmitted to the production-increasing well 9, the formation in the area near the wellbore of the production-increasing well 9 is induced to sink and deform, the unconsolidated rock in the formation is destroyed, and complex microcracks are generated. As the time of depressurization mining of natural gas hydrates increases, the formation hydrates continue to decompose, resulting in a decrease in the mechanical strength of the formation around the wellbore, the sediments continue to sink and compact, and formation voids are gradually formed around the production wellbore. The stability of the hydrate-containing formation above the reservoir changes, and the formation also sinks, forming a new communication channel to expand the mining range, thereby achieving the purpose of deep transformation of the reservoir.

[0041] The above detailed description is a specific description of a feasible embodiment of the present invention. The embodiment is not intended to limit the patent scope of the present invention. Any equivalent implementation or modification that does not depart from the present invention should be included in the patent scope of this case.

Claims

1. A method for hydrate production by artificially inducing regional sedimentation to transform a reservoir, characterized in that: The steps include: Step 1: Select a suitable natural gas hydrate reservoir as the mining target, build an offshore mining platform in the offshore area, place the drilling equipment and casing required for drilling and well construction on the offshore mining platform, and place the gas storage tanks, gas-liquid-solid separation storage equipment, pumping material storage equipment and liquid storage heating equipment required for mining the hydrate reservoir; the hydrate reservoir includes the upper overburden, the upper reservoir area, the well construction and production area, the lower disturbance area and the lower overburden from top to bottom; build a production well for hydrate mining, the production well passes through the seawater area, the upper overburden, the upper reservoir area and the well construction and production area from top to bottom, and the production well includes a production vertical section and a production horizontal section connected to it; build a production stimulation well in the lower disturbance area below the production well in the well construction and production area; Step 2: Drilling of stimulation wells in the lower disturbance zone and construction of several horizontal branch wells in the lower zone of the production well; Step 3: Drilling a production well in the well construction and production area. Build a horizontal production section in the middle of the hydrate reservoir. Connect the horizontal section to the vertical production section and extend it upward to the offshore production platform. After drilling the production well, run a production well cementing casing. A production well cement sheath is built on the outside of the casing. During production, run a production string inside the production well cementing casing. Step 4: Perform reservoir stimulation in the production well construction area. Run a coiled tubing equipped with hydraulic perforating and pumping equipment, extract hot seawater from the liquid storage and heating equipment for hydraulic injection, and form penetrating hydraulic jet holes in the production well cementing casing and the production well cement sheath. Then, pump the material storage equipment into the hydraulic jet holes to inject ethylene glycol and curing resin. The liquid ejected from the hydraulic jet holes forms a high-conductivity channel, which connects the production well and the stimulation well. Step 5: After completing the construction phase, a production tubing string is lowered into the production well to extract hydrates. The gas-liquid-solid mixture obtained from the extraction is lifted to the offshore production platform. After separation and treatment by the gas-liquid-solid separation and storage equipment, pure natural gas is extracted for storage and transportation to the application site.

2. A hydrate production device for artificially inducing regional sedimentation to transform a reservoir, characterized by: The invention comprises an offshore mining platform, a gas storage tank, a gas-liquid-solid separation storage device connected to the gas storage tank, a pumping material storage device, a storage liquid heating device, a production well and a production-increasing well; the offshore mining platform is built in an offshore area where a natural gas hydrate reservoir is explored; the hydrate reservoir comprises, from top to bottom, an upper covering layer, an upper reservoir area, a well construction and production area, a lower disturbance area and a lower covering layer; the production-increasing well is built in the lower disturbance area, and the production-increasing well comprises a vertical section and a horizontal section connected thereto, and the horizontal section is provided with several horizontal branch wells, and the horizontal branch wells are built in the lower disturbance area; a production well for hydrate mining is built, and the production well passes through four areas from top to bottom: the seawater area, the upper covering layer, the upper reservoir area and the well construction and production area, and the production well comprises a production vertical section and a production section connected thereto The horizontal production section is constructed in the middle of the hydrate reservoir and is located above the production stimulation well, and the vertical production section extends upward to the offshore mining platform; the production well includes a production well cement sheath, a production well cementing casing and a production well production string from the outside to the inside; a continuous oil pipe equipped with a hydraulic perforating and pumping device is lowered into the reservoir transformation process, and hot seawater in the liquid storage and heating device is extracted for hydraulic injection, thereby forming penetrating hydraulic jet holes on the production well cementing casing and the production well cement sheath; the pumping material storage device injects ethylene glycol and curing resin into the hydraulic jet holes, and the liquid ejected from the hydraulic jet holes forms a high-conductivity channel, which connects the production well with the production stimulation well; the production well is respectively connected to the gas-liquid-solid separation storage device, the pumping material storage device and the liquid storage and heating device.

3. The hydrate production device for artificially inducing regional sedimentation to transform a reservoir according to claim 2 is characterized in that: The stimulation well is filled with sand particles, the diameter of which is not less than 10 to 20 times the particle diameter of the reservoir sand particles in the hydrate reservoir.

4. The hydrate production device for artificially inducing regional sedimentation to transform a reservoir according to claim 2 is characterized in that: Several of the horizontal branch wells are located on the same layer parallel to the production horizontal section and are distributed in a comb-tooth shape; or, several of the horizontal branch wells are distributed in a fishbone shape at intervals and extend in multiple directions.

5. The hydrate production device for artificially inducing regional sedimentation to transform a reservoir according to claim 2 is characterized in that: Several of the horizontal branch wells are located in different layers; or, among the several horizontal branch wells, some of the horizontal branch wells are located in the same layer, and the other part of the horizontal branch wells are located in different layers.

6. The hydrate production device for artificially inducing regional sedimentation to transform a reservoir according to claim 2 is characterized by: The production string of the production well is equipped with a sand control screen, which is located at the production horizontal section after being installed and lowered; the sand control screen is filled with gravel.

7. The hydrate production device for artificially inducing regional sedimentation to transform a reservoir according to claim 6 is characterized in that: The particle size of the gravel is 6 to 10 times the particle size of the reservoir particles in the well production area or the lower disturbance area.

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