Medium-and-long-term monitoring device for marine scientific drilling well and laying method

Abstract

The invention belongs to the technical field of well logging monitoring, and discloses a long-term monitoring device in a marine scientific drilling well and a laying method.The device comprises a wellhead reentry cone sleeve system and a monitoring system, the wellhead reentry cone sleeve system abuts against the seabed mud surface, and the monitoring system is arranged on the wellhead reentry cone sleeve system in a penetrating mode and extends into a drilling well; the in-well monitoring unit comprises a casing pipe, a packing pipeline, a stratum monitoring structure and a geological monitoring structure, the casing pipe is arranged in a drilling well in a penetrating mode, the packing pipeline is arranged on the outer side of the casing pipe in a sleeving mode, a plurality of packers are arranged on the packing pipeline at intervals in the vertical direction in a sleeving mode, and the packers have an expanded packing state and an unexpanded contraction state. In the packing state, the packers abut against the inner wall of a drilling well, and a packing space is defined by every two adjacent packers and the inner wall of the drilling well; a monitoring assembly is arranged in each packing space, the monitoring assemblies can monitor the temperature and pressure in the corresponding packing space and sample fluid in the corresponding packing space, and long-term in-situ monitoring of multiple stratums is achieved.

Description

Technical Field

[0001] The present invention relates to the field of well logging monitoring technology, and in particular to a medium- and long-term monitoring device for marine scientific drilling wells and a deployment method thereof. Background Art

[0002] Marine drilling is a scientific project that is mainly aimed at obtaining core samples, and based on this, studies in the fields of solid earth and geodynamics, climate and environmental evolution, and deep biosphere. After the core samples are collected, various observation data can be collected by sending long-term observation devices into the sampled boreholes to obtain in-situ observation data of the formations with more dimensions and larger time and space scales.

[0003] There are currently two ways of underground detection: geophysical logging and long-term underground observation. Geophysical logging is the process of exploring and exploiting oil, coal and metal ore bodies. It uses various instruments to measure the physical parameters of underground rock formations and the technical conditions of the wells, analyze the recorded data, and conduct geological and engineering research. In the existing technology, the sensors of geophysical logging are generally integrated on a probe, which is lowered to the bottom of the well through a drill pipe or cable, and then recovered to complete data collection. It mainly collects current formation status data, lacks dynamic change trends on a long time scale, and cannot monitor biological and material changes in the well, and does not have comprehensive observation capabilities. Summary of the invention

[0004] The purpose of the present invention is to provide a medium- and long-term monitoring device for marine scientific drilling wells and a deployment method, which can realize dynamic change monitoring on a long time scale and has comprehensive observation capabilities.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] On the one hand, a medium- and long-term monitoring device for marine scientific drilling wells is provided, comprising:

[0007] The wellhead re-entry cone casing system is in contact with the seabed mud surface and connected to the drilling well;

[0008] The monitoring system is arranged in the wellhead re-entry cone casing system, and includes a wellhead monitoring unit and a well monitoring unit. The wellhead monitoring unit is used to collect monitoring results and sample fluids. The well monitoring unit includes:

[0009] A casing extending vertically and passing through the well;

[0010] An isolation pipeline is sleeved on the outside of the casing, and a plurality of packers are sleeved on the isolation pipeline along the vertical intervals. The packers are annular and have an inflated isolation state and an uninflated contracted state. In the isolation state, the packers abut against the inner wall of the well, and two adjacent packers and the inner wall of the well enclose an isolation space;

[0011] A formation monitoring structure, comprising a plurality of monitoring components arranged at intervals along a vertical direction on the outer wall of the casing, wherein one monitoring component is arranged in each of the isolation spaces, each of the monitoring components is connected to the wellhead monitoring unit, and the monitoring components can monitor the temperature and pressure in the isolation space and sample the fluid in the isolation space;

[0012] The geological monitoring structure is arranged in the open hole at the bottom side of the casing, coupled with the stratum, and connected to the wellhead monitoring unit, and is used to monitor natural seismic waves and stratum slippage.

[0013] As an optional solution for the long-term monitoring device of marine scientific drilling wells, the formation monitoring structure also includes a plurality of screens, which are arranged vertically at intervals outside the isolation pipeline and are correspondingly mounted on the outside of the plurality of monitoring components.

[0014] As an optional solution for the long-term monitoring device of marine scientific drilling wells, the monitoring component includes a temperature monitor, a pressure detection tube and a fluid sampling tube. The temperature monitor is arranged on the casing and passes through the isolation pipeline; the pressure detection tube and the fluid sampling tube are both arranged on the casing and are connected to the fluid in the corresponding isolation space.

[0015] As an optional solution for the long-term monitoring device of marine scientific drilling wells, the wellhead monitoring unit includes:

[0016] A fixed pipe is abutted against the wellhead re-entry cone casing system, the fixed pipe is surrounded by a fixed cavity, a fixed frame is arranged in the fixed cavity, and an installation channel for allowing the geological monitoring structure to pass through is opened on the fixed frame; a plurality of fluid sampling ports are opened on the fixed frame, and the plurality of fluid sampling ports are connected to the plurality of fluid sampling pipes in a one-to-one correspondence;

[0017] A top plug rotatably disposed on the upper end of the fixed tube;

[0018] A plurality of microorganism sampling components are disposed on the fixing frame and are connected to the plurality of fluid sampling ports in a one-to-one correspondence;

[0019] A plurality of dissolved gas detection components are arranged on the fixing frame and are connected to a plurality of the fluid sampling ports in a one-to-one correspondence.

[0020] As an optional solution for the medium- and long-term monitoring device for marine scientific drilling wells, the wellhead monitoring unit also includes a power supply component, which is connected to the monitoring component and the geological monitoring structure.

[0021] As an optional solution for the long-term monitoring device of marine scientific drilling wells, the wellhead re-entry cone casing system includes:

[0022] A fixing plate is in contact with the mud surface and is provided with a fixing hole for allowing the monitoring system to pass through;

[0023] The guide structure is conical, arranged on the fixing plate, and connected to the fixing hole.

[0024] As an optional solution for the long-term monitoring device of marine scientific drilling wells, the monitoring system also includes an operating platform, which is arranged between the wellhead monitoring unit and the in-well monitoring unit and abuts against the guide structure.

[0025] As an optional solution for the medium- and long-term monitoring device of marine scientific drilling wells, the geological monitoring structure includes a broadband seismograph, a volume strain gauge and a grouting side pipe. The broadband seismograph and the volume strain gauge are vertically arranged in the open hole. The grouting side pipe is connected to the gap between the broadband seismograph and the inner wall of the open hole, and is connected to the gap between the volume strain gauge and the inner wall of the open hole.

[0026] On the other hand, a method for deploying a medium- and long-term monitoring device for a marine scientific drilling well is provided, which is applied to any of the medium- and long-term monitoring devices for a marine scientific drilling well described above, and comprises the following steps:

[0027] S1: A drill pipe structure is connected to the mother ship, and the wellhead re-entry cone casing system is sleeved on the drill pipe structure. The drill pipe structure drills downward to form a shallow borehole and sends the wellhead re-entry cone casing system to the seabed mud surface;

[0028] S2: Assemble the monitoring system on the mother ship, pass the inner drilling tool structure through the monitoring system, extend the inner drilling tool structure into the shallow borehole and continue to drill downward to form a wellbore and an open hole, and send the in-well monitoring unit into the wellbore; after the monitoring system is sent to the preset monitoring position, release the connection between the inner drilling tool structure and the monitoring system, hang the in-well monitoring unit on the wellhead re-entry cone casing system, and retract the inner drilling tool structure;

[0029] S3: sending the geological monitoring structure into the open hole at the bottom of the well and coupling it with the formation;

[0030] S4: Pressurizing the plurality of packers to adjust them to a sealing state to form a plurality of sealing spaces, and draining the disturbed fluid in the sealing spaces;

[0031] S5: Use the formation monitoring structure and the geological monitoring structure to perform long-term monitoring.

[0032] As an optional solution for the deployment method of the long-term monitoring device in the marine scientific drilling well, the inner drilling tool structure includes:

[0033] A drill pipe connected to the mother ship, wherein a casing delivery connector is provided on the drill pipe, and the casing delivery connector has a locked state connected to the well monitoring unit and an unlocked state separated from the well monitoring unit;

[0034] A reamer while drilling is arranged on the drill rod, and is provided with an reaming surface with adjustable size, and has an expanded state in which the reaming surface is larger than the cross-sectional area of ​​the casing, and a evasive state in which the reaming surface is not larger than the cross-sectional area of ​​the casing;

[0035] A drill bit is connected to the bottom end of the drill rod.

[0036] Beneficial effects of the present invention:

[0037] The present invention provides a medium- and long-term monitoring device for marine scientific drilling wells, including a wellhead re-entry cone casing system and a monitoring system. The wellhead re-entry cone casing system is abutted against the seabed mud surface and connected to the drilling well. The monitoring system is arranged on the wellhead re-entry cone casing system. The monitoring unit in the well includes a casing, a sealing pipeline, a formation monitoring structure and a geological monitoring structure. The casing extends vertically and is arranged in the drilling well. The sealing pipeline is sleeved on the outside of the casing. A plurality of packers are sleeved vertically at intervals along the sealing pipeline. The packers are annular and have an expanded sealing state and an unexpanded contracted state. When the packer is in the sealing state, the packer abuts against the inner wall of the drilling well, and two adjacent packers and the inner wall of the drilling well enclose an isolation space; each isolation space is provided with a monitoring component, and each monitoring component is connected to the wellhead monitoring unit. The monitoring component can monitor the temperature and pressure in the corresponding isolation space and sample the fluid in the corresponding isolation space to realize in-situ monitoring of multiple formations. The geological monitoring structure is set in the open hole at the bottom of the casing, coupled with the formation, and connected to the wellhead monitoring unit to monitor natural seismic waves and formation slip. The device can achieve long-term monitoring of multiple formations and multiple observation parameters, can reflect the trend of changes on a long time scale, and has the ability to carry out long-term seabed geophysical observations. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic diagram of the overall structure of a medium- and long-term monitoring device for marine scientific drilling wells provided in a specific embodiment of the present invention;

[0039] Figure 2It is a schematic diagram of the first process of the method for deploying a long-term monitoring device for a marine scientific drilling well provided in an embodiment of the specific implementation of the present invention;

[0040] Figure 3 It is an overall schematic diagram of a monitoring system provided by an embodiment of a specific implementation mode of the present invention;

[0041] Figure 4 It is an overall schematic diagram of the inner drilling tool structure provided by a specific embodiment of the present invention;

[0042] Figure 5 It is a schematic diagram of the second process of the method for deploying a medium- and long-term monitoring device for a marine scientific drilling well provided in an embodiment of the present invention;

[0043] Figure 6 It is a schematic diagram of the third process of the method for deploying a long-term monitoring device for a marine scientific drilling well provided in an embodiment of the specific implementation manner of the present invention;

[0044] Figure 7 It is a schematic diagram of the fourth process of the method for deploying a medium- and long-term monitoring device for a marine scientific drilling well provided in an embodiment of the present invention;

[0045] Figure 8 It is a schematic diagram of the fifth process of the method for deploying a long-term monitoring device for marine scientific drilling wells provided in an embodiment of the specific implementation of the present invention.

[0046] In the figure:

[0047] 100. drilling; 101. open hole; 102. shallow borehole;

[0048] 1. Wellhead re-entry cone casing system; 11. Fixed plate; 12. Guide structure;

[0049] 2. Monitoring system;

[0050] 21. Wellhead monitoring unit; 211. Fixing frame; 2111. Fluid sampling port; 212. Top plug; 213. Microbial sampling assembly; 214. Dissolved gas detection assembly; 215. Power supply assembly; 216. Pressure sensor array; 217. Packer pressure port; 218. Data acquisition module;

[0051] 22. Well monitoring unit;

[0052] 221, casing; 222, packer pipeline; 2221, packer;

[0053] 223, formation monitoring structure; 2231, screen tube; 2232, temperature monitor; 2233, pressure detection tube; 2234, fluid sampling tube;

[0054] 224. Geological monitoring structure; 2241. Broadband seismograph; 2242. Volumetric strain gauge; 2243. Umbilical cable;

[0055] 23. Working platform;

[0056] 3. Drill pipe structure;

[0057] 4. Internal drilling tool structure; 41. Drill rod; 411. Casing delivery connector; 42. Drilling reamer; 43. Drill bit; 44. Drill collar; 45. Screw motor; 46. Stabilizer;

[0058] 5. ROV. DETAILED DESCRIPTION

[0059] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0060] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0061] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0062] In the description of this embodiment, the terms "upper", "lower", "right" and other directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplified operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0063] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0064] like Figure 1 As shown, this embodiment provides a medium- and long-term monitoring device for marine scientific drilling wells, including a wellhead re-entry cone casing system 1 and a monitoring system 2. The wellhead re-entry cone casing system 1 is abutted against the seabed mud surface and is connected to the drilling well 100. The monitoring system 2 is penetrated through the wellhead re-entry cone casing system 1. The monitoring system 2 includes a wellhead monitoring unit 21 and a well monitoring unit 22. The wellhead monitoring unit 21 is used to collect monitoring results and sample fluids. The well monitoring unit 22 includes a casing 221, an isolation pipeline 222, a formation monitoring structure 223 and a geological monitoring structure 224. The casing 221 extends vertically and is penetrated through the drilling well 100. The isolation pipeline 222 is sleeved on the outside of the casing 221. A plurality of packers 2221 are sleeved along the vertical intervals on the isolation pipeline 222. The packers 2221 are annular and have an expanded isolation state and a non-expanded contracted state. When the packer 2221 is in the isolation state, the packer 2221 abuts against the inner wall of the well 100, and two adjacent packers 2221 and the inner wall of the well 100 enclose an isolation space; the formation monitoring structure 223 includes a plurality of monitoring components arranged at vertical intervals on the outer wall of the casing 221, each isolation space is provided with a monitoring component, each monitoring component is connected to the wellhead monitoring unit 21, and the monitoring component can monitor the temperature and pressure in the corresponding isolation space and sample the fluid in the corresponding isolation space to achieve in-situ monitoring of multiple formations. The geological monitoring structure 224 is arranged in the open hole 101 at the bottom side of the casing 221, coupled with the formation, and connected to the wellhead monitoring unit 21, for monitoring natural seismic waves and formation slip. The device can achieve long-term monitoring of multiple formations and multiple observation parameters, and can reflect the changing trend on a long time scale.

[0065] Specifically, the packer 2221 is a conventional setting in the art, and its specific structure and working principle are not described in detail here.

[0066] Optionally, the wellhead re-entry cone casing system 1 includes a fixed plate 11 and a guide structure 12. The fixed plate 11 is in contact with the mud surface and is provided with a fixed hole that allows the monitoring system 2 to be installed, so as to increase the contact area between the wellhead re-entry cone casing system 1 and the mud surface and slow down its sinking rate below the mud surface. The guide structure 12 is conical, arranged on the fixed plate 11, and connected to the fixed hole. The conical setting can facilitate the installation of the monitoring unit 22 in the well, which is beneficial to improving the deployment efficiency.

[0067] Furthermore, the monitoring system 2 further includes an operating platform 23, which is disposed between the wellhead monitoring unit 21 and the in-well monitoring unit 22 and abuts against the guide structure 12. The operating platform 23 is configured to carry a remotely operated vehicle (ROV5), which is used to regularly collect monitoring results collected by the wellhead monitoring unit 21.

[0068] Optionally, the formation monitoring structure 223 further includes a plurality of screen tubes 2231, which are arranged at intervals along the vertical direction outside the isolation pipeline 222, and are sleeved one by one outside the plurality of monitoring components. The arrangement of the screen tubes 2231 can filter fluid impurities in the isolation space and prevent impurities from entering the monitoring components. Specifically, the screen tubes 2231 are porous screen-like structures.

[0069] Furthermore, the monitoring component includes a temperature monitor 2232, a pressure detection tube 2233 and a fluid sampling tube 2234. The temperature monitor 2232 is arranged on the casing 221 and passes through the isolation pipeline 222 to monitor the temperature of the fluid in the isolation space; the pressure monitoring tube and the fluid sampling tube 2234 are both arranged on the casing 221 and are both connected to the fluid in the corresponding isolation space to monitor the fluid pressure and sample the fluid to achieve multi-parameter monitoring.

[0070] Specifically, the temperature monitor 2232, the pressure detection tube 2233 and the fluid sampling tube 2234 are all existing devices that have been disclosed in the prior art. Their specific structures and principles refer to the prior art and are not described in detail here.

[0071] Optionally, the geological monitoring structure 224 includes a broadband seismograph 2241, a volume strain gauge 2242 and a grouting side pipe. The broadband seismograph 2241 and the volume strain gauge 2242 are vertically arranged in the open hole 101. The grouting side pipe is connected to the gap between the broadband seismograph 2241 and the inner wall of the open hole 101, and is connected to the gap between the volume strain gauge 2242 and the inner wall of the open hole 101. Slurry is injected into the grouting side pipe to couple with the stratum to ensure the accuracy of monitoring the natural seismic waves and stratum slip of the stratum. Specifically, in this embodiment, the slurry injected into the grouting side pipe is concrete; the broadband seismograph 2241 and the volume strain gauge 2242 are both conventional devices in the field, and their specific structures and working principles are not repeated here.

[0072] Optionally, the wellhead monitoring unit 21 includes a fixed tube (not shown in the figure), a top plug 212, multiple microbial sampling components 213 and multiple dissolved gas detection components 214, wherein the fixed tube is abutted against the wellhead re-entry cone casing system 1, and the fixed tube is surrounded by a fixed cavity, and a fixed frame 211 is arranged in the fixed cavity, and an installation channel allowing a geological monitoring structure 224 to pass through is opened on the fixed frame 211 to facilitate the installation of the geological monitoring structure 224; a plurality of fluid sampling ports 2111 are opened on the fixed frame 211, and the plurality of fluid sampling ports 2111 are connected to a plurality of fluid sampling tubes 2234 one by one to realize in-situ fluid sampling of multiple formations; the top plug 212 is rotatably arranged at the upper end of the fixed tube to close the pipe mouth of the fixed tube to prevent the external fluid of the device from entering the interior of the device. A plurality of microbial sampling components 213 are arranged on the fixed frame 211, and are connected to the plurality of fluid sampling ports 2111 one by one, and the microbial sampling components 213 use a slow-release microbial culture nutrient source to ensure that the nutrient source is slowly released within a set time, maintain the persistent activity of the microorganisms, and realize microbial sampling and colonization culture; a plurality of dissolved gas detection components 214 are arranged on the fixed frame 211, and are connected to the plurality of fluid sampling ports 2111 one by one, and the dissolved gas detection components 214 use fluid decompression gas release and Raman spectroscopy in-situ detection methods to detect dissolved gas components in the fluid, and realize in-situ monitoring of key gases (such as methane, carbon dioxide, hydrogen, etc.).

[0073] That is to say, the fluid sampled through each fluid sampling tube 2234 can enter the corresponding fluid sampling port 2111, and each fluid sampling port 2111 is connected to a microbial sampling component 213 and a dissolved gas detection component 214 to achieve microbial sampling and dissolved gas detection in each formation.

[0074] Specifically, the microorganism sampling component 213 and the dissolved gas detection component 214 are both existing technologies and are not described in detail here.

[0075] Furthermore, the wellhead monitoring unit 21 also includes a power supply component 215, which is connected to the monitoring component and the geological monitoring structure 224 to provide power for long-term monitoring and ensure the smooth progress of long-term monitoring. Specifically, the power supply component 215 includes a fast-charging battery and a replaceable battery. The fast-charging battery can complete energy storage in a short time, and the replaceable battery can be replaced regularly to ensure energy supply for long-term monitoring. The fast-charging battery and the replaceable battery are both devices disclosed in the prior art and will not be described in detail here.

[0076] Specifically, a pressure sensor array 216 is also provided on the fixed frame 211, and the pressure detection tube 2233 of each monitoring component is connected to the pressure sensor array 216 to collect the pressure values ​​of multiple formations; a packer pressure port 217 is also provided on the fixed frame 211, and the packer pressure port 217 is connected to the isolation pipeline 222, and is configured to be connected to the injection pump on the ROV5, so as to pressurize and expand multiple packers 2221; a data acquisition module 218 is also provided on the fixed frame 211, and the pressure sensor array 216 and each temperature monitor 2232 are connected to the data acquisition module 218, which is used to collect and collect formation monitoring data. ROV5 is directly connected to the data acquisition module 218, and various monitoring data of each formation can be obtained. Exemplarily, the pressure sensor array 216 and the data acquisition module 218 are both prior art and are not described here.

[0077] In addition, this embodiment also provides a method for deploying a medium- and long-term monitoring device for a marine scientific drilling well, which is applied to the above-mentioned medium- and long-term monitoring device for a marine scientific drilling well, and includes the following steps:

[0078] S1: A drill pipe structure 3 is connected to the mother ship, and a wellhead re-entry cone casing system 1 is sleeved on the drill pipe structure 3. The drill pipe structure 3 drills downward to form a shallow borehole 102 and delivers the wellhead re-entry cone casing system 1 to the seabed mud surface.

[0079] The above steps are specific to this embodiment. Figure 2 As shown, the drill pipe structure 3 is connected to the mother ship, the wellhead re-entry cone casing system 1 is sleeved on the drill pipe structure 3, and the bottom end of the drill pipe structure 3 is connected to a jet drill bit 43, close to the seabed mud surface, and then mud is pumped into the drill pipe structure 3, and the loose sediments on the surface of the seabed mud surface are washed away by the mud ejected by the jet drill bit 43, so that the wellhead re-entry cone system smoothly reaches and abuts on the mud surface, and forms a shallow borehole 102; then the connection between the drill pipe structure 3 and the wellhead re-entry cone casing system 1 is released, and the drill pipe structure 3 is recovered. Specifically, the jet drill bit 43 is also a conventional device in the art, and its specific structure and distance are not repeated here.

[0080] S2: Assemble the monitoring system 2 on the mother ship, pass the inner drill tool structure 4 through the monitoring system 2, extend the inner drill tool structure 4 into the shallow borehole 102 and continue to drill downward to form a well 100 and a naked hole 101, and send the in-well monitoring unit 22 into the well 100; after the monitoring system 2 is sent to the preset monitoring position, release the connection between the inner drill tool structure 4 and the monitoring system 2, and hang the in-well monitoring unit 22 on the wellhead re-entry cone casing system 1, and retract the inner drill tool structure 4.

[0081] The above steps are specifically for this embodiment. According to the layer and depth to be observed, the following are assembled on the mother ship: Figure 3The monitoring system 2 shown in the figure is connected in sequence to the casing 221, the isolation pipeline 222, the screen 2231 and the wellhead monitoring unit 21; Figure 4 The inner drilling tool structure 4 shown passes through the monitoring system 2. Figure 5 As shown, the inner drilling tool structure 4 is connected to the mother ship, and the inner drilling tool structure 4 extends into the shallow borehole 102. Figure 6 As shown, the inner drilling tool structure 4 continues to drill downward to form a well 100 and an open hole 101. At the same time, the well monitoring unit 22 is sent into the well 100, and drilling, hole expansion, device deployment and installation are completed in one trip. After the monitoring system 2 is sent to the preset position, the connection between the inner drilling tool structure 4 and the monitoring system 2 is released, and the well monitoring unit 22 is hung on the wellhead re-entry cone casing system 1, and the inner drilling tool structure 4 is retracted.

[0082] Optionally, continue to refer to Figure 4 The inner drilling tool structure 4 includes a drill pipe 41, a borehole reamer 42 and a drill bit 43. The drill pipe 41 is connected to the mother ship. The drill pipe 41 is provided with a casing delivery connector 411. The casing delivery connector 411 has a locking state connected to the well monitoring unit 22 and an unlocking state separated from the well monitoring unit 22. When the inner drilling tool structure 4 is drilling downward, the casing delivery connector 411 is in a locking state connected to the well monitoring unit 22 to ensure the synchronous downward movement of the monitoring system 2 and the inner drilling tool structure 4; when the well monitoring unit 22 reaches the preset monitoring position, the casing delivery connector 411 is in an unlocking state separated from the well monitoring unit 22 to ensure the smooth recovery of the inner drilling tool structure 4. The borehole reamer 42 is provided on the drill pipe 41. The borehole reamer 42 is provided with an adjustable reaming surface, and has an expansion state in which the reaming surface is larger than the cross-sectional area of ​​the casing 221 and an avoidance state in which the reaming surface is not larger than the cross-sectional area of ​​the casing 221. When the inner drilling tool structure 4 is drilling downward, the reamer 42 is in an expanded state so as to form a well 100 with a diameter larger than the casing 221; when the inner drilling tool structure 4 carries the monitoring system 2 through the wellhead and reenters the cone casing system 1, the reamer 42 is adjusted to a evasive state; when the inner drilling tool structure 4 needs to be recovered to the mother ship, the reamer 42 is also adjusted to a evasive state to facilitate its recovery from the casing 221 of the monitoring system 2. The drill bit 43 is connected to the bottom end of the drill pipe 41 and is used to break rocks and drill downward.

[0083] Specifically, in the present embodiment, the reamer while drilling 42 is a conventional device in the art, and its specific structure and principle are not described in detail herein.

[0084] In addition, in this embodiment, a drill collar 44 is provided at the bottom of the drill rod 41, which is used to apply drilling pressure to the drill bit 43, reduce the vibration, swing, and jump of the drill bit 43, and make the drill bit 43 work smoothly. A screw motor 45 is also connected to the drill rod 41. When the inner drill tool is drilling downward, the mud pump is turned on, and the mud flow pumped out by the mud pump enters the screw motor 45, forming a certain pressure difference at the inlet and outlet of the motor, driving the rotor to rotate around the stator, and transmitting the speed and torque to the drill bit 43 through the universal shaft and the transmission shaft, thereby realizing the downward drilling of the inner drill tool structure 4. A stabilizer 46 is also provided between the screw motor 45 and the drill bit 43 to prevent the drill bit 43 from tilting and ensure that the overall downward movement direction of the inner drill tool structure 4 is accurate. Specifically, in this embodiment, the drill collar 44, the screw motor 45 and the stabilizer 46 are all conventional devices in the field, and their specific structures and principles are not repeated here.

[0085] S3: Send the geological monitoring structure 224 into the open hole 101 at the bottom of the well 100 and couple it with the stratum.

[0086] The above steps are specific to this embodiment. Figure 7 As shown, the volume strain gauge 2242 and the broadband seismometer 2241 are installed in sequence and connected to the umbilical cable 2243 respectively. The connected geological monitoring structure 224 is passed through the casing 221 and sent into the open hole 101 at the bottom of the well 100. Then, slurry is injected into the grouting side pipe to gradually fill the gap between the broadband seismometer 2241 and the inner wall of the open hole 101 and the gap between the volume strain gauge 2242 and the inner wall of the open hole 101. After the slurry solidifies, the coupling between the broadband seismometer 2241 and the formation and the coupling between the volume strain gauge 2242 and the formation can be realized. Specifically, in this embodiment, the umbilical cable 2243 is a conventional device in the art, and its specific structure and principle are not repeated here.

[0087] S4: Pressurize the multiple packers 2221 to a sealing state to form multiple sealing spaces, and then drain the disturbed fluid in each sealing space.

[0088] In the above steps, specifically in this embodiment, an injection pump is provided on the ROV5, and the injection pump is connected to the isolation pipeline 222. The multiple packers 2221 are pressurized by the injection pump, so that each packer 2221 is in an isolation state, forming multiple isolation spaces. Then, the suction pump on the ROV5 is used to drain the disturbed fluid in each isolation space to ensure the subsequent monitoring and sampling of the in-situ fluid. It should be noted that during the lowering process of the entire device, the fluid in each formation will be disturbed, causing the fluid in each formation to be disturbed and form a disturbed fluid.

[0089] Specifically, the injection pump can inject gas into the packer 2221 to achieve pressurization and expansion of the packer 2221; or, fluid, such as water, mud, etc., can be injected into the packer 2221 to achieve pressurization and expansion of the packer 2221.

[0090] S5: Use the formation monitoring structure 223 and the geological monitoring structure 224 to conduct long-term monitoring.

[0091] The above steps, specifically in this embodiment, use the formation monitoring structure 223 and the geological monitoring structure 224 to perform long-term monitoring, and the ROV5 regularly collects the monitoring data collected by the wellhead monitoring unit 21.

[0092] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A medium- and long-term monitoring device for marine scientific drilling wells, characterized in that: include: A wellhead re-entry cone casing system (1) is abutted against the seabed mud surface and connected to the drilling well (100); The monitoring system (2) is arranged in the wellhead re-entry cone casing system (1), and comprises a wellhead monitoring unit (21) and a well monitoring unit (22). The wellhead monitoring unit (21) is used to collect monitoring results and sample fluids. The well monitoring unit (22) comprises: A casing (221) extending vertically and penetrating the well (100); An isolation pipeline (222) is sleeved on the outside of the casing (221), and a plurality of packers (2221) are sleeved on the isolation pipeline (222) along vertical intervals. The packers (2221) are annular and have an expanded isolation state and a non-expanded contracted state. In the isolation state, the packers (2221) abut against the inner wall of the well (100), and two adjacent packers (2221) and the inner wall of the well (100) enclose an isolation space; A formation monitoring structure (223), comprising a plurality of monitoring components arranged at intervals along a vertical direction on the outer wall of the casing (221), wherein each of the isolation spaces is provided with a monitoring component, each of the monitoring components is connected to the wellhead monitoring unit (21), and the monitoring components are capable of monitoring the temperature and pressure in the isolation space and sampling the fluid in the isolation space; The geological monitoring structure (224) is arranged in the open hole (101) at the bottom side of the casing (221), coupled with the stratum, and connected to the wellhead monitoring unit (21), and is used to monitor natural seismic waves and stratum slippage.

2. The medium- and long-term monitoring device for marine scientific drilling wells according to claim 1 is characterized in that: The formation monitoring structure (223) further comprises a plurality of screen tubes (2231), wherein the plurality of screen tubes (2231) are arranged at intervals along the vertical direction on the outside of the isolation pipeline (222), and are sleeved one by one on the outside of the plurality of monitoring components.

3. The medium- and long-term monitoring device for marine scientific drilling wells according to claim 2 is characterized in that: The monitoring component includes a temperature monitor (2232), a pressure detection tube (2233) and a fluid sampling tube (2234); the temperature monitor (2232) is arranged on the casing (221) and passes through the isolation pipeline (222); the pressure detection tube (2233) and the fluid sampling tube (2234) are both arranged on the casing (221) and are both connected to the fluid in the corresponding isolation space.

4. The medium- and long-term monitoring device for marine scientific drilling wells according to claim 3 is characterized in that: The wellhead monitoring unit (21) comprises: A fixed pipe is abutted against the wellhead re-entry cone casing system (1), the fixed pipe is surrounded by a fixed cavity, a fixed frame (211) is arranged in the fixed cavity, and a mounting channel for allowing the geological monitoring structure (224) to pass through is provided on the fixed frame (211); a plurality of fluid sampling ports (2111) are provided on the fixed frame (211), and the plurality of fluid sampling ports (2111) are connected to the plurality of fluid sampling pipes (2234) in a one-to-one correspondence; A top plug (212) rotatably disposed on the upper end of the fixed tube; A plurality of microorganism sampling components (213) are disposed on the fixing frame (211) and are connected to the plurality of fluid sampling ports (2111) in a one-to-one correspondence; A plurality of dissolved gas detection components (214) are disposed on the fixing frame (211) and are connected to the plurality of fluid sampling ports (2111) in a one-to-one correspondence.

5. The medium- and long-term monitoring device for marine scientific drilling wells according to claim 4 is characterized in that: The wellhead monitoring unit (21) further comprises a power supply component (215), wherein the power supply component (215) is connected to the monitoring component and the geological monitoring structure (224).

6. The medium- and long-term monitoring device for marine scientific drilling wells according to claim 1 is characterized in that: The wellhead re-entry cone casing system (1) comprises: A fixing plate (11) is in contact with the mud surface and is provided with a fixing hole for allowing the monitoring system (2) to pass through; The guide structure (12) is conical, arranged on the fixing plate (11), and connected to the fixing hole.

7. The medium- and long-term monitoring device for marine scientific drilling wells according to claim 6 is characterized in that: The monitoring system (2) further comprises an operating platform (23), wherein the operating platform (23) is arranged between the wellhead monitoring unit (21) and the in-well monitoring unit (22), and is in contact with the guide structure (12).

8. The medium- and long-term monitoring device for marine scientific drilling wells according to claim 1 is characterized in that: The geological monitoring structure (224) comprises a broadband seismometer (2241), a volume strain gauge (2242) and a grouting side pipe. The broadband seismometer (2241) and the volume strain gauge (2242) are vertically arranged in the open hole (101). The grouting side pipe is connected to the gap between the broadband seismometer (2241) and the inner wall of the open hole (101), and is connected to the gap between the volume strain gauge (2242) and the inner wall of the open hole (101).

9. A method for deploying a medium- and long-term monitoring device for a marine scientific drilling well, characterized in that: The medium- and long-term monitoring device for marine scientific drilling wells as described in any one of claims 1 to 8 above comprises the following steps: S1: A drill pipe structure (3) is connected to the mother ship, and the wellhead re-entry cone casing system (1) is sleeved on the drill pipe structure (3). The drill pipe structure (3) drills downward to form a shallow borehole (102) and delivers the wellhead re-entry cone casing system (1) to the seabed mud surface; S2: Assembling the monitoring system (2) on the mother ship, passing the inner drilling tool structure (4) through the monitoring system (2), extending the inner drilling tool structure (4) into the shallow borehole (102) and continuing to drill downward to form a wellbore (100) and an open hole (101), and sending the in-hole monitoring unit (22) into the wellbore (100); after the monitoring system (2) is sent to a preset monitoring position, releasing the connection between the inner drilling tool structure (4) and the monitoring system (2), and hanging the in-hole monitoring unit (22) on the wellhead re-entry cone casing system (1), and retracting the inner drilling tool structure (4); S3: sending the geological monitoring structure (224) into the open hole (101) at the bottom of the well (100) and coupling it with the stratum; S4: Pressurizing the plurality of packers (2221) to a packed state to form a plurality of packed spaces, and draining the disturbed fluid in the packed spaces; S5: Use the stratum monitoring structure (223) and the geological monitoring structure (224) to carry out long-term monitoring.

10. The method for deploying a medium- and long-term monitoring device for a marine scientific drilling well according to claim 9, characterized in that: The inner drilling tool structure (4) comprises: A drill pipe (41) is connected to the mother ship, and a casing delivery connector (411) is provided on the drill pipe (41), and the casing delivery connector (411) has a locked state connected to the well monitoring unit (22) and an unlocked state separated from the well monitoring unit (22); A drilling reamer (42) is arranged on the drill rod (41), and is provided with an reaming surface with an adjustable size, and has an expanded state in which the reaming surface is larger than the cross-sectional area of ​​the casing (221) and a evasive state in which the reaming surface is not larger than the cross-sectional area of ​​the casing (221); The drill bit (43) is connected to the bottom end of the drill rod (41).

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