63results about "Underwater drilling" patented technology

Underwater drilling assemblies and systems are disclosed. The underwater drilling assemblies and systems include drill assemblies, frames for drill assemblies, and connection flange assemblies to be fastened to a ship skin. The underwater drilling assemblies and systems further include waste cartridges and automatic air-bleed valve assemblies.

The invention belongs to the technical field of deepwater drilling, and discloses a deepwater drilling system and a deepwater drilling method. The deepwater drilling system comprises a drilling ship, a waterproof unit, a regulation and control device, a blowout prevention device and a drilling device. The upper end of the waterproof unit is connected with a drilling ship and provided with a first penetrating channel. The regulation and control device is arranged at the lower end of the waterproof unit and provided with a plurality of connecting channels. The connecting channel has an open state and a closed state, and in the open state, the first penetrating channel communicates with the outside through the connecting channel. And the blowout preventer is arranged at the wellhead and is connected with the waterproof unit. And the first penetrating channel can be communicated with a second penetrating channel of the blowout preventer. The drilling device is arranged on the drilling ship and penetrates through the first penetrating channel, the second penetrating channel and the well mouth. The well drilling device is provided with a conveying channel, and drilling fluid can be conveyed to the lower end of the well drilling device through the conveying channel. When the system is used for drilling operation, the pressure borne by a stratum at a wellhead can be effectively reduced, and stratum fracturing is avoided.

The invention discloses a marine natural gas hydrate in-situ drilling and production robot which comprises a drilling group base body, the drilling group base body is of a cylindrical structure, the drilling group base body is sequentially connected with a large motor box and a data acquisition instrument box, the data acquisition instrument box is connected with a front small motor box, and a large motor is arranged in the large motor box and connected with a planetary gear assembly; the front small motor box is connected with a central shaft, the central shaft is sequentially sleeved with a front movement mechanism and a rear movement mechanism, the end part of the central shaft is connected with a rear small motor box, the front small motor box controls the front movement mechanism, the rear small motor box controls the rear movement mechanism, and the rear small motor box is connected with a post-processing container; a center pipe is arranged on the planetary gear assembly, a flow channel is arranged in the center of the center pipe, flow channel teeth are arranged on the periphery of the end of the center pipe, and a plurality of roller bits are arranged on the outer edge of the drill group base body towards the well bottom face. The problem that in the existing marine natural gas hydrate exploitation process, the integrity and stability of a shaft are damaged is solved.

This invention discloses an underwater drilling assembly and system. The underwater drilling assembly and system includes a drilling assembly, a frame for the drilling assembly, and a connecting flange assembly to be secured to a hull. The underwater drilling assembly and system also includes a waste bin and an automatic vent valve assembly.

The application belongs to the technical field of static rock breaking, and discloses an underwater static rock breaking device and method, which are used for breaking rock. The rock is provided with a containing hole, and the underwater static rock breaking device is arranged in the containing hole. The underwater static rock breaking device comprises a fixed pipe assembly, a first flexible pipe, a water injection pipe and a freezing pipe line. The first flexible pipe is connected with one end of the fixed pipe assembly and surrounds the fixed pipe assembly to form a freezing cavity. The water injection pipe can extend into the freezing cavity and inject liquid water into the freezing cavity. When the liquid water is injected into the freezing cavity through the water injection pipe, the first flexible pipe can expand and tightly adhere to the hole wall of the containing hole, and the fixed pipe assembly can be clamped with the hole wall to lock the first flexible pipe. The freezing pipe line can extend into the freezing cavity and freeze the liquid water in the freezing cavity. When the liquid water in the freezing cavity is frozen into solid water, the volume of the solid water is increased, which can make the first flexible pipe further expand and press the hole wall until the rock is broken, and no vibration, explosion or toxic substance is generated, which is safe and environmentally friendly.

The invention discloses a drilling and fixing integrated drilling device and method for a deep sea natural gas hydrate exploitation system. The drilling device comprises a hollow drill rod, a plurality of continuous pipe separation units and a hollow drill bit which are fixedly connected from top to bottom in the axial direction, and according to the method, the multi-well guiding suction anchor, the rope soil taking equipment, the drilling device and the seabed drilling machine are lowered to a seabed to be positioned and leveled through a small and medium-sized workboat and are fixedly connected with the multi-well guiding suction anchor; the seabed drilling machine controls the drilling device to drill along the multi-well guide suction anchor, and the rope soil taking equipment takes soil; and the pipe is replaced until the target depth is drilled, the drilling device conducts self well cementation and well completion through the self-expansion packer and the pre-filled gravel screen pipe, and the drilling device is completed after equipment is recycled. The device has continuous and integrated operation capacity of well drilling, soil taking, well cementation and well completion, the cost is effectively reduced, the efficiency is remarkably improved, rapid construction, convenient well cementation and economic well completion of a deep sea hydrate mining system are achieved, and a new thought and method are provided for safe and efficient mining of deep sea hydrates.

The present invention relates to a civil engineering apparatus for excavation, comprising multiple device modules, the civil engineering apparatus having an excavation mechanism constructed from at least two device modules and a load-bearing structure for suspending the excavation mechanism and moving it vertically to form a pit in the ground, wherein a personnel passage is constructed in or at the at least two device modules, the personnel passage allowing personnel to pass horizontally along the at least two device modules.

The invention discloses an underwater pebble covering layer drilling method which comprises the following steps that S1, a variable-diameter casing pipe is pressed into water in a hydraulic pressing-in mode, the bottom of the variable-diameter casing pipe penetrates through a pebble layer and abuts against underwater rock, and the variable-diameter casing pipe comprises a large casing pipe body and a small casing pipe body which are connected with each other; s2, a drill rod is inserted into the variable-diameter casing pipe, and the drill rod is started; and S3, firstly crushing the cobblestones by the drill rod, and then drilling holes in the underwater rock. The variable-diameter casing pipe can penetrate through a cobblestone layer through hydraulic pressing, and the problem that a traditional casing pipe is difficult to penetrate through the cobblestone layer is solved. The large sleeve and the small sleeve form the variable-diameter sleeve, when the variable-diameter sleeve is lowered, the influence of water flow on the large sleeve is small, when the small sleeve penetrates through the cobblestone layer, the diameter of the small sleeve is smaller, the small sleeve can be inserted into the cobblestone layer more easily, the junction of the small sleeve and the large sleeve is in smooth transition, and the large sleeve can be inserted into the cobblestone layer along with the small sleeve conveniently. The small casing pipe is more attached to the drill rod, accurate guiding is conveniently provided for the drill rod, and work of the drill rod is facilitated.

The present application belongs to the technical field of submarine pipeline laying, and particularly relates to a high-precision butt joint method, system and equipment for submarine pipeline laying under rocks, aiming to solve the problem that the accurate butt joint construction of the existing submarine directional drilling crossing technology can only be carried out in the horizontal direction of land or the crossing drilling between land and land. The present application comprises the following steps: through a sea drilling ship, a positioning drill bit carrying a magnetic source beacon is made to drill down through a drill rod in the butt joint sea area, a guide source is set, the first butt joint drilling tool is guided to drill to a preset butt joint area and the through position is recorded through the guide source, the first butt joint drilling tool is retracted, the second butt joint drilling tool is guided to the through position through the guide source, and directional drilling is completed. The present application enables the horizontal directional drilling construction based on magnetic source positioning to carry out rock butt joint operation in any sea area where offshore drilling operation can be carried out, and solves the problem that the butt joint in rocks between the ocean and islands can only be carried out in one-way operation.

The invention discloses a suction anchor wellhead device for a deep sea natural gas hydrate radial well cluster exploitation system and an operation method. The deep sea suction anchor comprises a top cover and a peripheral barrel, the top cover is fixed to an upper port of the peripheral barrel, a top cover rail is arranged on the top cover, and the drilling machine is installed on the top cover rail through a drilling machine moving platform; the deep-sea suction anchor is provided with a vertical pipeline used for a vertical well on the central axis of a barrel shell structure, a guide supporting plate is arranged in the barrel shell structure of the deep-sea suction anchor, a mining well guide pipeline used for an inclined well is embedded in the barrel shell structure of the deep-sea suction anchor, and the mining well guide pipeline vertically penetrates through the guide supporting plate in the inclined direction and extends. The stability of a multi-well structure is guaranteed through multi-plate staggered supporting and guiding combination, the drilling machine moving platform and the top cover rail cooperate to achieve inter-well movement of the drilling machine, efficient and automatic construction operation of a deep-sea radial well cluster exploitation system is integrally achieved, and novel seabed fixing equipment and an operation method are provided for a deep-sea natural gas hydrate exploitation system.

This utility model provides a multi-stage correction system for offshore wind power exploration guide casings. The guide casing includes a connecting casing section, a correction casing, a drill collar, and a cutting edge casing. Adjacent connecting casing sections are connected by correction casings. The lower end of the lowest connecting casing section is sequentially connected to the drill collar and the cutting edge casing. M winches are evenly distributed circumferentially at the upper end of the guide casing. M correction latches are evenly distributed circumferentially on the drill collar. Each correction latch is connected to the corresponding winch via a steel wire rope. The upper end of the guide casing has multiple casing correction winch groups, the same number as the correction casings in the guide casing. Each casing correction winch group includes N winches evenly distributed circumferentially at the upper end of the guide casing. N correction latches are evenly distributed circumferentially on the correction casing. Each correction latch is connected to the corresponding winch via a steel wire rope. The multi-stage correction mechanism of this invention ensures that each section of the guide sleeve is in a vertical position.

The application relates to a deep-water drilling chamber indoor vibration experiment device and an experiment method. The device comprises a derrick, a flexible drill string, a rigid drill string, a rock sample clamping mechanism, an air wave generator, a torque dynamometer and a sensor group. The actual marine environment is simulated through the air wave generator, and the dynamic characteristic parameters of the drill string system are collected through the torque dynamometer and the sensor, so that the problem that the actual marine environment load cannot be simulated, and the dynamic characteristic parameters of the drill string system cannot be accurately and comprehensively obtained in the prior art is solved.

The application discloses an underwater rock mass drilling device, which comprises a drilling assembly, a height adjusting assembly and a supporting assembly, the drilling assembly comprises a drill rod and a drill bit, the height adjusting assembly is provided with a sleeve, the supporting assembly comprises a rectangular frame body which is surrounded by four telescopic members connected in a head-to-tail mode, and a plurality of telescopic rods are connected between the rectangular frame body and the sleeve. The application further discloses a drilling method based on the underwater rock mass drilling device, which can adjust the position of the drill bit through the plurality of telescopic rods, improve the accuracy of the drilling position, and can successively complete a plurality of drilling tasks within the range surrounded by the plurality of telescopic members, thereby improving the work efficiency.

The invention belongs to the technical field of carbon dioxide sequestration, and particularly relates to a method for rapidly synthesizing hydrate and stably burying CO2 in a shallow-middle sea area sedimentary layer, which comprises the following steps: S1, mounting a rotatable jet drill bit at the front end of a CO2 injection pipe; s2, a drill bit at the front end of the CO2 injection pipe is drilled into a certain area below a seabed sedimentary layer of the shallow-middle sea area; s3, a liquid CO2 storage tank is connected with a CO2 injection pipe to inject high-pressure liquid CO2; s4, stirring along with blades; s5, the length of the CO2 injection pipe is gradually extended, the rotatable drill bit is installed at the end of the CO2 injection pipe, the spiral blades are welded to the rotatable drill bit, the liquid CO2 is injected to drive the rotatable drill bit to rotate, the stirring effect is achieved, the liquid CO2 is promoted to be rapidly dissolved into seawater, hydrate is further rapidly generated and does not move to the seabed to float, and therefore the CO2 injection pipe can be recycled. The CO2 can be prevented from being dissolved in the ocean after being in direct contact with seawater subsequently, stable storage of CO2 in the sea area of 500-2650 meters can be met, and the method can also promote rapid generation of hydrates even in the sea area exceeding 2650 meters.

An underwater drilling assembly and system is disclosed. The underwater drilling assembly and system includes a drilling assembly, a frame for the drilling assembly, and a connection flange assembly to be secured to a hull of a vessel. The underwater drilling assembly and system also includes a waste box and an automatic vent valve assembly.

The invention relates to the field of ocean engineering, in particular to a telescopic drill rod supporting device and an offshore directional drilling system, and aims to relieve the technical problem of low construction efficiency of offshore directional drilling in related technologies. The telescopic drill rod supporting device comprises a supporting ship. The multiple sections of supporting boxes are distributed in a straight line and connected to form a supporting unit, and one end of the supporting unit is hinged to the stern of the supporting ship; the buoyancy tanks are arranged at the ends, away from the supporting ship, of the supporting tanks; and the driving mechanism is arranged between the two adjacent supporting boxes and used for driving one section of supporting box, away from the supporting ship, in the two adjacent supporting boxes to retract into or extend out of the other section of supporting box. The offshore directional drilling system includes a retractable drill rod support device. According to the telescopic drill rod supporting device, rapid building and withdrawing of an offshore directional drilling system can be achieved, the efficiency of offshore directional drilling operation is improved, and meanwhile safety and reliability during offshore directional drilling operation can be guaranteed.

The application discloses underwater rock-soil drilling equipment and an underwater rock-soil exploration method, and relates to the technical field of sampling equipment.The application comprises a supporting cylinder, a moving disc is slidably connected in the supporting cylinder, a sampling cylinder is arranged in the moving disc, a drill rod is arranged in the sampling cylinder, and a conveying auger is fixedly connected to the surface of the drill rod; and a driving assembly is arranged in the supporting cylinder.The application realizes the all-around sampling capacity of the underwater rock-soil drilling equipment through the design of the driving assembly, the driving system composed of a first hydraulic rod, a supporting disc, a circular ring and a first motor cooperates with the synergetic effect of a guide rail ring and a positioning rod, so that the sampling cylinder can be adjusted in multiple angles, the structure enables the drill rod to be adjusted at any drilling position within the coverage range of the supporting cylinder, the sampling efficiency is significantly improved, and multiple-position sampling can be completed at one time, and reliable data support is provided for the spatial heterogeneity research of underwater geological conditions.

The application discloses a rotary drilling process in pile foundation construction, which is used for underwater drilling and comprises the following steps: according to a drilling torque, a drilling cylinder corresponding to the drilling torque is assembled, and specifically, the length and the inner diameter of the drilling cylinder are adjusted to correspond to the drilling torque; along the bottom of the drilling cylinder, the rolling cutters arranged in an inclined mode or a vertical mode are assembled in units to form a rolling cutter surface; a drill rod is connected to the upper part of the drilling cylinder through a drill rod connecting sleeve; on the outer side of the drilling cylinder, a flow guide assembly is assembled with the rolling cutters as the starting position; the drill rod is started, the rolling cutters drill a core column along the wall of the drilling cylinder while the drill rod rotates, water on the outer side of the drilling cylinder moves upwards along the flow guide assembly, and a vortex is formed at the top, and water at the top flows downwards along the inner wall of the drilling cylinder under the action of gravity to form a water circulation path; when the water moves upwards, the water carries away the broken stones generated when the rolling cutters are broken under the action of the vortex, and a moving channel is formed at the vortex for the flow of the broken stones. The application realizes the drilling of the whole core column.

The invention relates to the technical field of oceanographic engineering geological exploration equipment, in particular to an offshore down-the-hole while-drilling CPT tool which comprises a multi-channel drill rod assembly which comprises a multi-channel drill rod, a cable pipeline, a slurry pipeline, an air pipeline and a standby channel are integrated in the multi-channel drill rod, and the multi-channel drill rod assembly is used for synchronously transmitting electric signals, slurry media and compressed air. The static sounding penetration mechanism and the underground rock breaking and hole sweeping mechanism are integrated, synchronous transmission of power and media is achieved through the multi-channel drill rod, a continuous operation mode of seamless connection of sounding while drilling is constructed, and after a section of stratum penetration test is completed by the tool, the tool does not need to be lifted out of a hole, and the construction efficiency is improved. The pneumatic motor can be immediately started to drive the drill bit to conduct next-section hole sweeping, the traditional intermittent circulation technology of testing, drill lifting, hole sweeping, recycling and descending is changed, and offshore CPT operation is converted into a continuous process from frequent starting and stopping.

The application discloses a deep-sea while-drilling casing well completion equipment system and a working method thereof, and relates to the technical field of drilling equipment. The system comprises a casing connecting nipple, a feeding tool, a steel cable fisher, a heavy hammer, a sitting nipple, a winged drill bit and a guide drill bit. The casing feeding tool is simple in structure, and only needs to be rotated, without the need of complex actions such as mechanical ball throwing, pressure holding, downward pressure shearing and the like. The winged drill bit assembly is used to complete the rotary drilling construction of the casing well section, and can guarantee that the well hole meets the design depth and the well hole shape is more regular than the jet hole forming rule. After the casing is placed, the next well hole drilling work can be directly performed without the need of tripping out. The technology is controllable, and the cost is lower. The heavy hammer is thrown, the blades of the winged drill bit are opened, the heavy hammer is fished and recovered after the winged drill bit completes the predetermined work, the blades are retracted, the expansion and recovery of the blades are circular, the drilling work of more than two well holes can be completed without tripping out and replacing the drill bit, and the production efficiency can be greatly improved.

The invention discloses a precise positioning and depth control method for underwater drilling blasting, relates to the technical field of underwater blasting, and aims to effectively control blast hole positioning deviation through data real-time linkage calibration, collect water level data through double-source cooperation of an automatic moisture indicator and a water level pressure sensor, eliminate interference and ensure data precision. An intelligent ultra-deep value decision-making model based on machine learning is constructed, historical engineering data and current actual measurement parameters are combined, an optimal ultra-deep value is automatically output, and in the trial explosion optimization stage, an optimal parameter combination is formed by monitoring the vibration speed and observing the explosion effect and optimizing the explosion parameters; a layered charging structure and a hole-by-hole delay detonating network are adopted, the maximum single-section detonating explosive amount is hierarchically controlled according to the distance of a protected object, vibration and shock wave data are continuously monitored in the blasting process, and parameters are adjusted immediately when the data exceed the standard; and the data is fed back to the intelligent model to complete iterative optimization, so that more accurate parameter support is provided for subsequent blasting.

Underwater drilling assemblies and systems are disclosed. The underwater drilling assemblies and systems include drill assemblies, frames for drill assemblies, and connection flange assemblies to be fastened to a ship skin. The underwater drilling assemblies and systems further include waste cartridges and automatic air-bleed valve assemblies.

The invention discloses an underground coring system which can provide bit pressure in a hydraulic mode, does not need additional balance weight and can ensure accurate adjustment of the bit pressure. The underground coring device comprises an underground coring device body and an operation carrier, the underground coring device body comprises a hydraulic feeding assembly and a rotary sampling assembly, the hydraulic feeding assembly comprises a power assembly and a hydraulic oil cylinder assembly, the hydraulic oil cylinder assembly comprises a first cavity and a second cavity, and the power assembly is connected with the first cavity through a first oil way; the power assembly is connected with the second cavity through a second oil way. When the power assembly extracts oil from the first cavity and conveys the oil to the second cavity, the hydraulic oil cylinder assembly drives the rotary sampling assembly to drill into hard rock; when the power assembly extracts oil from the second cavity and conveys the oil to the first cavity, the hydraulic oil cylinder assembly drives the rotary sampling assembly to be separated from the hard rock; the operation carrier is provided with winding and unwinding equipment and a cable connected with the hydraulic feeding assembly, and the winding and unwinding equipment can drive the underground coring device to dive or float upwards by unwinding or winding the cable.

The invention relates to the technical field of oceanographic engineering geological exploration equipment, in particular to an offshore down-the-hole while-drilling CPT tool which comprises a multi-channel drill rod assembly which comprises a multi-channel drill rod, a cable pipeline, a slurry pipeline, an air pipeline and a standby channel are integrated in the multi-channel drill rod, and the multi-channel drill rod assembly is used for synchronously transmitting electric signals, slurry media and compressed air. The static sounding penetration mechanism and the underground rock breaking and hole sweeping mechanism are integrated, synchronous transmission of power and media is achieved through the multi-channel drill rod, a continuous operation mode of seamless connection of sounding while drilling is constructed, and after a section of stratum penetration test is completed by the tool, the tool does not need to be lifted out of a hole, and the construction efficiency is improved. The pneumatic motor can be immediately started to drive the drill bit to conduct next-section hole sweeping, the traditional intermittent circulation technology of testing, drill lifting, hole sweeping, recycling and descending is changed, and offshore CPT operation is converted into a continuous process from frequent starting and stopping.

The invention provides a deep sea drilling machine bottoming process calculation method considering rheological sediment effect, which comprises the following steps of: dividing the whole bottoming process of a drilling machine into three stages of free falling, first bottoming of two groups of supporting legs and simultaneous bottoming of three groups of supporting legs, and establishing a coordinate transformation matrix between a world coordinate system and a drilling machine follow-up coordinate system, forming a multi-degree-of-freedom kinetic equation; seawater additional mass force, fluid Coriolis force, linear fluid damping force, sediment supporting force and sediment friction force are introduced into the multi-degree-of-freedom kinetic equation, and nonlinear environmental force changing along with speed, subsidence depth and time is obtained; taking a seabed slope angle, an initial pitch angle, a sediment rigidity coefficient and an internal friction angle as independent variables, performing iterative solution on the multi-degree-of-freedom kinetic equation by adopting a genetic algorithm, and outputting an extreme working condition parameter combination enabling a drilling machine to have a maximum acceleration extreme value, a maximum supporting force extreme value or a maximum sinking depth extreme value; accurate calculation and safety evaluation of the drilling machine bottoming dynamic behavior are achieved.

The invention relates to a method for creating access (2) to an earth cavity (3) arranged below a body of water (1) from a water surface (5) of the body of water (1), wherein a) a protective tube (7) is inserted from the water surface (5) above the earth cavity (3) into a watercourse bed (9) of the water body (1), such that the protective tube (7) extends from the watercourse bed (9) to above a water surface (5) of the water body (1), wherein b) a drill string (11) having a tool (13) arranged at its end is lowered through the protective tube (7) to the bottom of the water body (9), wherein c) using the tool (13) an opening (15) is made in a ceiling (17) of the earth cavity (3).

The application provides a kind of anti-inclination seabed rock and polymetallic sulfide exploration drilling machine and method, it is related to deep sea environment monitoring field.The self-moving and multi-station fixed-point monitoring deep sea autonomous environmental monitoring platform, including diving shell, the diving shell is provided with sonar detection equipment, environmental monitoring equipment, water control equipment and six drive mechanisms, the diving shell inside is fixedly connected with two isolation plates.The self-moving and multi-station fixed-point monitoring deep sea autonomous environmental monitoring platform, guarantees that diving shell, environmental monitoring equipment, signal transceiver, water control equipment, sonar detection equipment, sampling tube, drive mechanism, electric push rod, rotary motor, hydraulic cylinder and other components of deep sea autonomous environmental monitoring platform monitor the ocean environment quickly, improve the present situation that monitoring platform needs to use ocean research vessel to drive, reduce the degree of participation of staff, reduce the error that may be caused by manual control, guarantee the efficiency of ocean environment monitoring.

This invention relates to the field of underwater rock drilling and excavation technology, specifically to a rock drilling control method based on a drop hammer rock drill. The control method includes: S1: controlling the rock drill to travel along the track to a preset rock drilling point; S2: bottom probing method: controlling the drum to reverse, releasing the traction rope to control the rock hammer to descend, maintaining the traction rope on the rock hammer during descent until the rock hammer touches the bottom, and recording the position of the rock hammer head after touching the bottom as the bottom probing reference point; S3: hammer lifting method: controlling the drum to rotate forward, lifting the rock hammer to a preset rock drilling starting elevation; S4: hammer dropping method: at the rock drilling starting elevation, controlling the transmission connection between the rock hammer and the drum to disconnect, allowing the rock hammer to undergo free fall motion and impact the rock surface. The entire rock drilling process can be automated through the control system, enabling unmanned operation and intervention, improving operational accuracy and efficiency.

The invention discloses a double-gradient well drilling device which comprises a marine riser, a drill pipe and a pressure adjusting mechanism. The drill pipe comprises an inner pipe, an outer pipe and a marine riser, the outer pipe and the inner pipe are coaxially sleeved in sequence, a first annular area is formed between the inner pipe and the outer pipe, and a second annular area is formed between the outer pipe and the marine riser; the pressure adjusting mechanism comprises at least one of a first pressure adjusting part and a second pressure adjusting part, and at least part of the first pressure adjusting part is arranged in the first annular space area so as to divide the first annular space area into a first upper area and a first lower area; the first pressure adjusting part is used for adjusting the opening degree of a first communication channel between the first upper area and the first lower area; the second pressure adjusting part is used for adjusting the opening degree of the second communication channel between the first annular space area and the second annular space area. According to the scheme, the problem that a double-gradient drilling device involved in the related technology cannot quickly and accurately adjust the pressure when facing the emergency situation of pressure sudden change can be solved.

The invention relates to the technical field of rotary drilling rigs, in particular to a rotary drilling rig for underwater pile foundation pore-forming, which comprises a vehicle body, a movable arm, a drilling rod and a drilling bucket, a main bucket door plate capable of being opened and closed is arranged at the lower end of the drilling bucket, and a plurality of expansion plates are hinged to the lower opening of the drilling bucket through a plurality of groups of connecting mechanisms; a cylindrical structure can be defined by the multiple expansion plates; an unfolding driving mechanism is arranged in the drilling bucket, and when the drilling bucket rotates, centrifugal force generated by rotation of the drilling bucket can be converted into mechanical force for driving the multiple expansion plates to be unfolded outwards synchronously. An openable and closable mechanism is formed below the drilling bucket through the hinged expansion plates, the expansion plates are folded into a cylindrical shape to increase the soil loading capacity during excavation, and the expansion plates are unfolded outwards to form a trumpet-shaped frustum-shaped opening during soil discharging, so that the contact area and friction force between soil and an outlet are greatly reduced, the whole clay can slide out more easily, and the construction efficiency is improved. The problem of clogging of the soil discharge port is solved.