CN116006161B - Visual rock debris migration simulation device and method for drilling mud circulation pipeline without marine riser - Google Patents

Abstract

The invention relates to a visual rock debris migration simulation device and method for a drilling mud circulation pipeline without a riser, belonging to the field of ocean deep water oil and gas exploration and development, and comprising a mud circulation pipeline simulation part, an auxiliary circulation part, a sand adding part and a data detection and processing part; the mud circulation pipeline simulation part is used for simulating a rock debris migration and deposition process in the deep water non-riser drilling mud circulation pipeline; the auxiliary circulation part is used for providing drilling fluid for the visual circulation pipeline; the sand adding part is used for providing rock fragments with different throwing rates; the data detection and processing part comprises a high-speed camera and a computer. Under the visual condition, the invention can simulate the influence of different drilling fluid flows, rock chip generation amounts, pipeline inclination angles, rock chip particle sizes, rock chip types and rock chip shapes on the rock chip migration rule of the drilling mud without the marine riser, has the advantages of rich functions, simple and compact structure, small occupied area, light and flexible operation, easy reconstruction and disassembly, safe use and lower construction and operation cost.

Description

A visual cuttings migration simulation device and method for drilling mud circulation pipeline without riser

Technical Field

The invention relates to a device and method for simulating the visualized rock cuttings migration of a riser-free drilling mud circulation pipeline, belonging to the technical field of deep-water marine oil and gas exploration and development.

Background technique

Riserless drilling is a drilling technology that achieves sealing between the wellbore and seawater by installing a suction module at the wellhead on the seabed. It does not use a riser during the drilling process. It can return cuttings and mud to the drilling platform through the return pipeline. In the pump suction pipeline module, since the mud circulation pipeline system connecting the suction module and the lift pump module is a hose connected to the mud return pipeline hard pipe, the hose is affected by the seabed environment, and there are pipeline bends and small corners, which have an adverse effect on the movement of cuttings in the pipe. In addition, due to the long transportation distance of the horizontal section pipeline, cuttings are easily deposited and become a cuttings bed, thereby blocking the pipeline and causing drilling accidents. Therefore, studying the law of cuttings movement in the mud circulation pipeline of riserless drilling is of great significance to the design optimization of the parameters of the mud lift pump group.

The migration and deposition of returned cuttings during riserless drilling is affected by many factors, such as drilling fluid return flow rate, well inclination, cuttings type, cuttings particle size, and cuttings volume fraction. The process of cuttings migration and deposition is not easy to observe during drilling. The previous cuttings migration simulation equipment was used to study the annulus experimental conditions of directional wells with drill pipes, or because of the limitations of the simulation research equipment design, only a small range of simulation can be performed for some research variables such as well inclination, which has limitations. Therefore, there is an urgent need for an experimental device that can simulate and visualize the law of cuttings migration in the mud circulation pipeline of riserless drilling. The device includes a mud circulation pipeline simulation part, an auxiliary circulation part, a sand adding part, and a data detection and processing part. The experimental device can be used to conduct cuttings transport experiments without a drill pipe. It can visualize the cuttings transport in the pipeline and obtain results such as the pressure loss in the pipeline, cuttings transport characteristics, and cuttings concentration. It can simulate the cuttings transport under a variety of different working conditions including different pipeline shapes. Through the solid-liquid separation part of the device, the cuttings from the simulated experiment can be reused repeatedly. At the same time, the experiment is a low-cost experiment conducted under low-pressure safety conditions, which will provide a reliable way to design and optimize the parameters of the riser-free mud lift pump group.

Summary of the invention

In view of the deficiencies in the prior art, the present invention provides a visual cuttings migration simulation device and method for a riser-less drilling mud circulation pipeline. Under visualization conditions, the device and method can simulate the effects of different drilling fluid flow rates, cuttings generation amounts, pipeline inclination angles, cuttings particle sizes, cuttings types and cuttings shapes on the cuttings migration law of the return pump suction pipeline in the riser-less drilling mud cuttings migration. The device has rich functions, a simple and compact structure, a small footprint, is light and flexible to operate, is easy to modify and disassemble, is safe to use, and has low construction and operation costs.

The present invention adopts the following technical solution:

A visualized cuttings transport simulation device for a drilling mud circulation pipeline without a riser, comprising a mud circulation pipeline simulation part, an auxiliary circulation part, a sand adding part and a data detection and processing part;

The mud circulation pipeline simulation part includes a pipeline support base, a visible pipeline support plate, three sections of transparent glass tubes, and a pipeline inclination adjustment frame. The three sections of transparent glass tubes are interconnected to form a visual circulation pipeline. The visual circulation pipeline is fixed on the visible pipeline support plate. The visible pipeline support plate is installed on the pipeline support base, and the inclination of the visible pipeline support plate is adjusted by the pipeline inclination adjustment frame; one end of the visual circulation pipeline is connected to a hose A, and the other end is connected to a hose B. A pressure sensor is provided at the connection between the hose A, the three sections of transparent glass tubes, and the hose B, for measuring the pressure at different positions; the mud circulation pipeline simulation part is used to simulate the rock cuttings migration and deposition process of the return pump suction pipeline in the deepwater riser-free drilling mud circulation pipeline;

One end of the auxiliary circulation part is connected to the hose A, and the other end is connected to the hose B, which is used to supply drilling fluid to the visualization circulation pipeline, separate the drilling fluid from the cuttings passing through the visualization circulation pipeline, and recover the experimental cuttings, while controlling the pressure of each section of the device to ensure the safety of the experiment;

The sand adding part includes a sand tank, a sand adding auger and a sand adding motor. A feeding end is provided at the bottom of the sand tank, which is connected to the feeding end of the sand adding auger. After the rock cuttings in the sand tank enter the sand adding auger, they are transported to the discharge end of the sand adding auger under the action of the sand adding motor, so as to provide rock cuttings with different delivery rates to the simulation part of the mud circulation pipeline.

The data detection and processing part includes a high-speed camera and a computer. The high-speed camera is used to capture the real-time status of the visual circulation pipeline and transmit it to the computer. The computer is connected to multiple pressure sensors to obtain pressure information in real time.

Furthermore, high-speed cameras can be used to capture and record the trajectory of rock cuttings, the flow pattern of rock cuttings, and the time of rock cutting removal, and to upload and store the real-time images of the solid-liquid two-phase flow in the pipe and the values of the four pressure sensors into a computer. At the same time, the electromagnetic flowmeter can record the flow rate of drilling fluid delivered to the circulation pipeline by the screw pump and upload the data to the computer.

Preferably, the three sections of transparent glass tubes are connected by two metal connecting rings A, each of which is a hollow cylinder with external threads at both ends, which are connected and sealed with the internal threads at the ends of the transparent glass tubes, so that the characteristics of rock debris migration can be visually observed;

The visualization circulation pipeline is connected to the hose A and the hose B through a metal connecting ring B. The metal connecting ring B is also a hollow cylinder, one end of which is provided with an external thread, which cooperates with the internal thread of the end of the transparent glass tube, and the other end is directly connected to the hose A or the hose B;

The middle outer walls of the two metal connecting rings A and the two metal connecting rings B are provided with threaded holes for spirally mounting pressure sensors to perform real-time detection of liquid flow pressure at different positions of the visual circulation pipeline;

Preferably, the three sections of transparent glass tubes have the same or different shapes, and the transparent glass tubes are straight tubes, horizontally bent glass tubes with equal diameters, partially vertically bent upward glass tubes with equal diameters, or partially vertically bent downward glass tubes with equal diameters.

The shape of the transparent glass tube of the present invention can be replaced to simulate working conditions such as pipeline bending and small corners affected by the seabed environment, so as to realize the study of the influence of different pipeline shapes on the migration of rock cuttings in the pipe. When the shape of the transparent glass tube changes, the shape and size of the transparent glass tube support, the fixing hole for fixing the transparent glass tube and the metal connecting ring should be adaptively changed.

Preferably, the pipeline support base as a whole is a frame structure composed of two long beams and three pairs of legs, one end of which is connected to one end of the visible pipeline support plate through a pin shaft;

Two through holes of different diameters are provided on the two legs at one end of the pipeline support base, which are a large through hole and a small through hole. The large through hole is used to install the pin shaft, and the small through hole is used to fix the pin shaft.

Preferably, the visible pipeline support plate includes a visible pipeline support plate body, the visible pipeline support plate body is an inverted U-shaped structure, a plurality of transparent glass tube supports are welded on the upper surface of the visible pipeline support plate body, and each transparent glass tube support is provided with a fixing hole for fixing the transparent glass tube;

Preferably, a vertical plate is welded on the upper surface of the visible pipeline support plate body, and a pin hole is provided on the vertical plate for cooperating with the pipeline inclination adjustment frame;

The pipeline inclination adjustment frame is composed of two identical 90° arc structures, each of which has a plurality of adjustment holes at equal central angles. The adjustment holes on the two arc structures are arranged correspondingly, and after installation, the distances from the plurality of adjustment holes to the pin shaft are the same, so as to ensure that after the visible pipeline support plate is rotated, the pin hole on it can be aligned with the adjustment hole at any height;

The two arc structures are welded to the middle of the two long beams of the pipeline support base. The visible pipeline support plate and three sections of transparent glass tubes are located between the two arc structures. A pair of adjustment holes in the two arc structures are connected to the pin holes of the vertical plate through pins. The pins are stuck on the adjustment holes at different heights of the pipeline inclination adjustment frame, so that the visible pipeline support plate can drive the visualized circulation pipeline to rise and fall along the pin shaft, thereby adjusting the inclination angle of the visualized circulation pipeline.

The two pipeline inclination adjustment frames of the present invention are respectively welded to the inner side of the pipeline support base, and a pin hole is arranged on the vertical plate on one side of the visible pipeline support plate. Since one side of the visible pipeline support plate is fixed to the pipeline support base by a pin shaft and the other end is free, the visible pipeline support plate is rotated so that the pin hole on the vertical plate is aligned with the adjustment holes at different height positions of the pipeline inclination adjustment frame. The pin is inserted to fix the visible pipeline support plate and keep a fixed angle between the visible pipeline support plate and the upper surface of the pipeline support base. The pipeline inclination adjustment frame has 7 adjustment holes arranged at equal angles along the arc direction, which can realize a total of 7 angles of 0, 15, 30, 45, 60, 75 and 90 between the visible pipeline support plate and the upper surface of the pipeline support base, and realize the cuttings migration experiment of 7 kinds of well inclination angles from 0 to 90 degrees. Of course, the setting of the adjustment holes can also be encrypted according to actual conditions.

Preferably, two bearing through holes are provided on the U-shaped structure at one end of the visible pipeline support plate body;

The pin shaft comprises a pin shaft body, two bearings and a nut. The pin shaft body is a stepped shaft, comprising a large shaft section with a larger shaft diameter and a small shaft section with a smaller shaft diameter. The small shaft section is provided with threads for matching with the nut.

A limited retaining edge is arranged at the end of the large shaft section, and a retaining spring groove is arranged at a certain interval in the middle. The distance between the two retaining spring grooves is equal to the distance between the two bearing through holes of the visible pipeline support plate body. A retaining spring is arranged in the retaining spring groove to fix the retaining spring; the two bearings are flange bearings, and the large diameter end faces of the flange bearings are aligned with the retaining spring grooves, and are respectively sleeved on the large shaft section, and the axis is limited by the retaining spring;

During installation, the small shaft section of the pin shaft is inserted from the large through hole of the pipe support base, passes through the bearings on the two bearing through holes in turn, and finally passes through the small through hole of the pipe support base until the limiting retaining edge at the end of the large shaft section of the pin shaft contacts the end face of the large through hole of the pipe support base, and finally fixed to the small shaft section of the pin shaft with a nut.

The visualization circulation pipeline of the present invention is installed on a visible pipeline support plate and is fixed and limited by four transparent glass tube supports welded on the visible pipeline support plate. At the same time, the bearing through holes of the visible pipeline support plate are connected to the large through holes and small through holes of the pipeline support base through pins to form a hinge structure.

Preferably, the auxiliary circulation part includes a rotary vibrating screen, a cuttings recovery barrel, a screw pump, a water screen bracket, a drilling fluid tank, a tee pipe A, a tee pipe B and a tee pipe C. The rotary vibrating screen and the drilling fluid tank are placed above the water screen bracket and fixedly connected to the water screen bracket. The screw pump is placed inside the water screen bracket. The hose A, the tee pipe A, the tee pipe B, the tee pipe C and the hose B constitute an auxiliary circulation pipeline. The hose A connects the outlet end of the visualization circulation pipeline and the feed port at the top of the rotary vibrating screen. The rotary vibrating screen is used for solid-liquid separation. The separation port at the bottom thereof falls into the cuttings recovery barrel. The separation port on the right is connected to the drilling fluid tank. The bottom of the drilling fluid tank is connected to the suction end of the screw pump. The screw pump sucks in the drilling fluid and pumps it into the visualization circulation pipeline at a certain flow rate.

Preferably, the three sections of transparent glass tubes are made of glass fiber reinforced plastic composite materials, hose A and hose B are flexible tubes, tee pipes A, B and C are all made of stainless steel, and the experimental fluid is drilling fluid.

Preferably, end a of the three-way pipe B is connected to the outlet end of the screw pump, end b of the three-way pipe B is connected to the inlet of the electromagnetic flowmeter, end c of the three-way pipe B is connected to end a of the three-way pipe A, end b of the three-way pipe A is connected to the side opening of the drilling fluid tank, end c of the three-way pipe A is connected to the side opening of the sand tank, and a valve is provided on the connecting pipeline between the side opening of the drilling fluid tank and end b of the three-way pipe A18, and the sand tank can be depressurized by controlling the opening of the valve; end a of the three-way pipe C is connected to the outlet end of the electromagnetic flowmeter, the electromagnetic flowmeter is connected to the computer, end b of the three-way pipe C is connected to the outlet end of the sand adding auger, and end c of the three-way pipe C is connected to the inlet end of the visualization circulation pipeline through the hose B.

Preferably, the sand tank comprises a sand tank body, a sand delivery port is arranged on the top of the sand tank body, a sand tank cover is welded on the upper part of the sand delivery port, a quick connector is connected to the sand tank cover, the quick connector comprises a male head and a female head, the male head is welded on the sand tank cover, and a pluggable structure is formed between the male head and the female head;

Preferably, the sand tank, the sand adding auger and the sand adding motor are all fixed on the sand tank bracket, the sand tank bracket comprises a steel frame body, a clamping ring is arranged on the top of the steel frame body, bolt holes are arranged on the clamping ring, the sand tank is provided with a sand tank clamping ring, the clamping ring on the steel frame body is the same in shape as the sand tank clamping ring, and they are bolted together through a plurality of bolt holes;

The upper part of the steel frame body is threadedly connected with a connecting steel sheet A and a connecting steel sheet B, and the sand-adding auger is welded to the connecting steel sheet A and the connecting steel sheet B. After the sand-adding auger is welded to the connecting steel sheet A and the connecting steel sheet B on the steel frame body, it is fixed to the steel frame body by threaded connection;

One side of the steel frame body is threadedly connected to a motor seat plate, and the motor seat plate is provided with a motor mounting groove for mounting a sand adding motor.

Furthermore, the inlet at the top of the sand tank can be opened to add sand again. After closing the valve, drilling fluid and sand coexist in the sand tank, and the liquid pressure in the sand tank is equal to the liquid pressure in the circulation pipeline.

The pressure relief principle of the sand tank is: when the screw pump is turned on, the drilling fluid will enter the sand tank through the tee pipe B and the tee pipe A. At this time, the sand inlet on the sand tank must be closed, otherwise the drilling fluid will spray out. When adding sand to the sand tank again, the pressure of the sand tank needs to be released. At this time, the valve is opened, and the drilling fluid in the sand tank will flow into the drilling fluid tank to achieve pressure relief.

Furthermore, after the cuttings are loaded into the sand tank from the sand tank cover, they will enter the sand-feeding auger along the feeding end at the bottom of the sand tank. The rate at which the cuttings are injected into the tee pipe C can be adjusted by adjusting the speed of the sand-feeding motor. The cuttings are carried by the drilling fluid to form a solid-liquid two-phase flow and enter the simulated part of the drilling mud pipeline without a riser through the hose B.

Preferably, the drilling fluid tank comprises a drilling fluid tank body, a filter baffle is arranged in the drilling fluid tank body, and the drilling fluid tank body is divided into a front chamber and a rear chamber, and two through holes are arranged on the upper part of the filter baffle, and a filter screen A is arranged on the two through holes, and the drilling fluid separated from the rotary vibrating screen first enters the front chamber of the drilling fluid tank, and when the drilling fluid height in the front chamber reaches the height of the two through holes, the drilling fluid passes through the filter screen A and enters the rear chamber, thereby filtering the drilling fluid sent in by the rotary vibrating screen, thereby ensuring that the large drilling fluid tank contains fewer solid particles;

A side opening of the drilling fluid tank is arranged on the side wall of the rear chamber, and a water outlet is arranged at the bottom. The water outlet is connected to the suction end of the screw pump, and a filter screen B is arranged on the water outlet. The aperture of the filter screen B is smaller than the aperture of the filter screen A. The water outlet is a cylindrical boss with a height of 20 cm, and the water outlet is connected to the suction end of the screw pump. The screw pump is equipped with a variable frequency motor, which can suck in the drilling fluid and pump it into the circulation pipeline at a certain flow rate.

An experimental method for the above-mentioned riser-free drilling mud circulation pipeline visualization cuttings transport simulation device comprises the following steps:

(1) Open the valve to depressurize the sand tank, then add the test cuttings into the sand tank through the quick connector, close the valve, turn on the vibrating screen, turn on the screw pump to pump the drilling fluid out of the drilling fluid tank, and select the required drilling fluid flow rate by frequency conversion to control the speed of the screw pump;

(2) The adjusting pin is clamped in the adjustment holes at different height positions of the pipeline inclination adjustment frame, thereby adjusting the visible pipeline support plate to the inclination angle required for study;

(3) Turn on the sand adding motor and adjust the speed of rock cutting injection to make the rock cuttings enter the visual circulation pipeline evenly, and record the total injection amount and injection speed of rock cuttings;

(4) Record the readings of four pressure sensors and electromagnetic flowmeter, use a high-speed camera to shoot and upload to a computer, which records and displays the cuttings morphology, trajectory, thickness, and time when the cuttings are completely removed;

(5) By adjusting the displacement of the screw pump and repeating steps (1) to (4), the cuttings migration of the drilling fluid at different drilling fluid return rates in riser-free drilling can be simulated, and the electromagnetic flowmeter readings and pressure sensor readings are recorded. At the same time, the inlet cuttings type, inlet cuttings size, inlet cuttings shape, inlet cuttings volume fraction, pipeline inclination angle, pipeline shape, cuttings movement trajectory, cuttings deposition bed and cuttings restart are recorded, and the influence of different drilling fluid flow rates on the cuttings migration in the pipe is analyzed;

(6) adjusting the cuttings injection speed by controlling the speed of the sand adding motor and repeating steps (1) to (4) to simulate the cuttings migration of the drilling fluid under the conditions of different drilling speeds and different cuttings generation amounts in riser-free drilling, recording the electromagnetic flowmeter readings and the pressure sensor readings, and recording the inlet cuttings type, inlet cuttings size, inlet cuttings shape, inlet cuttings volume fraction, pipeline inclination angle, pipeline shape, cuttings movement trajectory, cuttings deposition bed and cuttings restart, and analyzing the influence of different cuttings generation amounts on the cuttings migration in the pipe;

(7) By controlling the pin to be stuck in the adjustment holes at different height positions of the pipeline inclination adjustment frame and repeating steps (1) to (4), the inclination angle of the visible pipeline support plate can be adjusted, thereby driving the visual circulation pipeline to rise and fall, and simulating the cuttings migration of the drilling fluid at different pipeline inclination angles in watertight pipe drilling, recording the electromagnetic flowmeter readings and pressure sensor readings, and at the same time recording the inlet cuttings type, inlet cuttings size, inlet cuttings shape, inlet cuttings volume fraction, pipeline inclination angle, pipeline shape, cuttings movement trajectory, cuttings deposition bed and cuttings restart, and analyzing the influence of different pipeline inclination angles on the cuttings migration in the pipe;

(8) By changing the type, size and shape of the cuttings loaded into the sand tank and repeating steps (1) to (4), the cuttings migration of the drilling fluid under different cuttings in riser-free drilling can be simulated, and the electromagnetic flowmeter reading and the pressure sensor reading are recorded. At the same time, the inlet cuttings type, inlet cuttings size, inlet cuttings shape, inlet cuttings volume fraction, pipeline inclination angle, pipeline shape, cuttings movement trajectory, cuttings deposition bed and cuttings restart are recorded, and the influence of different cuttings on the cuttings migration in the pipe is analyzed;

(9) By replacing transparent glass tubes of different shapes and repeating steps (1) to (4), the cuttings migration of drilling fluid under different pipe shapes in watertight pipe drilling can be simulated, and the electromagnetic flowmeter readings and pressure sensor readings are recorded. At the same time, the inlet cuttings type, inlet cuttings size, inlet cuttings shape, inlet cuttings volume fraction, pipe inclination angle, pipe shape, cuttings movement trajectory, cuttings deposition bed and cuttings restart are recorded, and the influence of different pipe shapes on the cuttings migration in the pipe is analyzed;

(10) After the experiment, turn off the sand adding motor first, wait until the rotary vibrating screen has separated the cuttings from the drilling fluid, then turn off the screw pump, then turn off the rotary vibrating screen, and pour the cuttings in the cuttings recovery bucket into the cuttings recovery area for reprocessing for reuse.

For any details not provided in the present invention, please refer to the prior art.

The beneficial effects of the present invention are:

1) The device of the present invention can simulate the influence of different drilling fluid flow rates, cuttings generation amounts, pipeline inclination angles, cuttings particle sizes, cuttings types and cuttings shapes on the cuttings migration law of the return pump suction pipeline of the non-waterproof pipe drilling mud cuttings migration under visualization conditions;

2) The auxiliary circulation part can fully separate the solid and liquid phases, and the cuttings can be recycled and reused, saving experimental materials;

3) This device can replace the experimental pipeline, so as to simulate the rock cuttings movement of the hose with a certain curvature used in the drilling without a watertight pipe;

4) The circulation pipeline designed for this device can ensure that the experiment is carried out under low-pressure safety conditions;

5) Compared with previous cuttings transport experimental devices, this device is more functional, simple and compact in structure, occupies a small area, is light and flexible to operate, is easy to modify and disassemble, is safe to use, and has low construction and operation costs.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the overall structure of a visualization cuttings transport simulation device for a riser-free drilling mud circulation pipeline in one embodiment of the present invention;

FIG2 is a schematic diagram of a visualized circulation pipeline explosion structure in one embodiment of the present invention;

FIG3 is a schematic diagram of the structure of a visible pipeline support plate in an embodiment of the present invention;

FIG4 is a schematic diagram of the structure of a pipeline support base in an embodiment of the present invention;

FIG5 is a schematic diagram of a pin structure in an embodiment of the present invention;

FIG6 is a schematic diagram of the structure of a pipeline inclination adjustment frame in an embodiment of the present invention;

7 is a schematic diagram of the matching relationship between the pipeline inclination adjustment frame, the pipeline support base, and the visible pipeline support plate in a certain embodiment of the present invention;

FIG8 is a side view of the matching relationship between the pipeline inclination adjustment frame, the pipeline support base, and the visible pipeline support plate in an embodiment of the present invention;

FIG9 is a schematic diagram of the structure of a water screen support in an embodiment of the present invention;

FIG10 is a schematic diagram of the structure of a drilling fluid tank in an embodiment of the present invention;

FIG11 is a schematic diagram of the structure of a sand tank in an embodiment of the present invention;

FIG12 is a schematic diagram of a sand pot support structure in an embodiment of the present invention;

FIG13 shows transparent glass tubes of various shapes, wherein (a) is a glass tube 1 having a certain diameter and partially bent vertically upward, (b) is a glass tube 2 having a certain diameter and partially bent vertically upward, (c) is a glass tube 1 having a certain diameter and partially bent vertically downward, and (d) is a glass tube 2 having a certain diameter and partially bent vertically downward;

Among them, 1. Pipeline support base, 1-1. Large through hole, 1-2. Small through hole, 2. Pin shaft, 2-1. Pin shaft body, 2-2. Bearing, 2-3. Circlip, 2-4. Nut, 2-5. Limit retaining edge, 3. Visible pipeline support plate, 3-1. Bearing through hole, 3-2. Visible pipeline support plate body, 3-3. Vertical plate, 3-4. Pin hole, 3-5. Transparent glass tube support, 3-6. Fixing hole, 4. Transparent glass tube one, 5. Pipeline inclination adjustment frame, 6-Pin, 7. Transparent glass tube two, 8-Metal connecting ring, 8-1. Metal connecting ring A, 8-2. Metal connecting ring B, 9. Pressure sensor, 10. Transparent glass tube three, 11. Hose A, 12. Cuttings recovery barrel, 13. Screw pump, 14. Water screen bracket, 15-Vortex vibrating screen, 16. Drilling fluid tank , 16-1, drilling fluid tank body, 16-2, filter baffle, 16-3, through hole, 16-4, water outlet, 16-5, side opening of drilling fluid tank, 17, valve, 18, tee pipe A, 19-tee pipe B, 20, electromagnetic flowmeter, 21, sand adding auger, 22, sand tank, 22-1, sand tank body, 22-2, side opening of sand tank, 22-3, sand delivery port, 22-4, feeding end, 22-5, sand tank clamping ring, 23, quick connector, 24, sand tank bracket, 24-1, steel frame body, 24-2, connecting steel sheet A, 24-3, clamping ring, 24-4, connecting steel sheet B, 24-5, motor seat plate, 24-6, motor mounting groove, 25, sand adding motor, 26, tee pipe C, 27, hose B, 28, high-speed camera, 29, computer.

Detailed ways

In order to enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of the present invention are clearly and completely described below, but are not limited to this. Anything not fully described in the present invention shall be based on conventional techniques in the art.

Example 1

A visualization cuttings transport simulation device for a non-water riser drilling mud circulation pipeline, as shown in FIG1-13, comprises a mud circulation pipeline simulation part, an auxiliary circulation part, a sand adding part and a data detection and processing part;

The mud circulation pipeline simulation part includes a pipeline support base 1, a visible pipeline support plate 3, three sections of transparent glass tubes (such as transparent glass tube one 4, transparent glass tube two 7 and transparent glass tube three 10 in Figures 1 and 2) and a pipeline inclination adjustment frame 5. The three sections of transparent glass tubes are connected to each other to form a visible circulation pipeline. The visible circulation pipeline is fixed on the visible pipeline support plate 3, and the visible pipeline support plate 3 is installed on the pipeline support base 1. The inclination of the visible pipeline support plate is adjusted by the pipeline inclination adjustment frame 5; one end of the visible circulation pipeline is connected to a hose A 11, and the other end is connected to a hose B 27. A pressure sensor 9 is provided at the connection between the hose A 11, the three sections of transparent glass tubes, and the hose B 27 to measure the pressure at different positions; the mud circulation pipeline simulation part is used to simulate the rock cuttings migration and deposition process of the return pump suction pipeline in the deepwater riser-free drilling mud circulation pipeline;

One end of the auxiliary circulation part is connected to the hose A 11, and the other end is connected to the hose B 27, which is used to supply drilling fluid to the visual circulation pipeline, separate the drilling fluid from the cuttings passing through the visual circulation pipeline, and recover the experimental cuttings, while controlling the pressure of each section of the device to ensure the safety of the experiment;

The sand adding part includes a sand tank 22, a sand adding auger 21 and a sand adding motor 25. A feeding end 22-4 is provided at the bottom of the sand tank, which is connected to the feeding end of the sand adding auger 21. After the rock cuttings in the sand tank enter the sand adding auger, they are transported to the discharge end of the sand adding auger 21 under the action of the sand adding motor 25, and are used to provide rock cuttings with different delivery rates to the simulation part of the mud circulation pipeline.

The data detection and processing part includes a high-speed camera 28 and a computer 29. The high-speed camera 28 is used to capture the real-time status of the visual circulation pipeline and transmit it to the computer 29. The computer is connected to multiple pressure sensors 9 to obtain pressure information in real time.

Furthermore, the high-speed camera 28 can be used to capture and record the trajectory of the cuttings, the flow pattern of the cuttings and the time of the cuttings removal, and to upload and store the real-time images of the solid-liquid two-phase flow in the recording pipe and the values of the four pressure sensors to the computer 29. At the same time, the electromagnetic flowmeter can record the flow rate of the drilling fluid delivered to the circulation pipeline by the screw pump and upload the data to the computer.

Example 2

A visualization rock cuttings transport simulation device for a drilling mud circulation pipeline without a water-riser, as described in Example 1, except that three sections of transparent glass tubes, a hose A 11, and a hose B are connected together by a metal connecting ring 8, wherein the three sections of transparent glass tubes are connected by two metal connecting rings A8-1, each of which is a hollow cylinder with external threads at both ends, which are connected and sealed with the internal threads at the ends of the transparent glass tubes, so that the characteristics of rock cuttings transport can be visualized;

As shown in FIG2 , the visualization circulation pipeline is connected to the hose A 11 and the hose B 27 through a metal connecting ring B 8-2. The metal connecting ring B is also a hollow cylinder, one end of which is provided with an external thread, which cooperates with the internal thread of the end of the transparent glass tube, and the other end is directly connected to the hose A 11 or the hose B 27;

The middle outer walls of the two metal connecting rings A 8-1 and the two metal connecting rings B 8-2 are provided with threaded holes for spirally mounting pressure sensors to perform real-time detection of liquid flow pressure at different positions of the visual circulation pipeline;

The shapes of the three sections of transparent glass tubes are the same or different. The transparent glass tubes are straight tubes, horizontally bent glass tubes with equal diameters, partially vertically bent upward glass tubes with equal diameters, or partially vertically bent downward glass tubes with equal diameters. FIG13 shows some of the shapes.

The shape of the transparent glass tube of the present invention can be replaced to simulate working conditions such as pipeline bending and small corners affected by the seabed environment, so as to realize the study of the influence of different pipeline shapes on the migration of rock cuttings in the pipe. When the shape of the transparent glass tube changes, the shape and size of the transparent glass tube support, the fixing hole for fixing the transparent glass tube and the metal connecting ring should be adaptively changed.

Example 3

A visualization cuttings transport simulation device for a drilling mud circulation pipeline without a riser, as described in Example 2, except that the pipeline support base 1 is a frame structure composed of two long beams and three pairs of legs, one end of which is connected to one end of a visible pipeline support plate through a pin 2;

Two through holes of different diameters are provided on the two legs at one end of the pipeline support base 1, namely a large through hole 1-1 and a small through hole 1-2. The large through hole 1-1 is used to insert the pin shaft, and the small through hole 1-2 is used to fix the pin shaft.

Example 4

A visual cuttings transport simulation device for a drilling mud circulation pipeline without a riser, as described in Example 3, except that a visual pipeline support plate 3 includes a visual pipeline support plate body 3-2, the visual pipeline support plate body 3-2 is an inverted U-shaped structure, and a plurality of transparent glass tube supports 3-5 are welded on the upper surface of the visual pipeline support plate body 2-2, and each transparent glass tube support 3-5 is provided with a fixing hole 3-6 for fixing the transparent glass tube;

Preferably, a vertical plate 3-3 is welded on the upper surface of the visible pipeline support plate body 3-2, and a pin hole 3-4 is provided on the vertical plate 3-3 for cooperating with the pipeline inclination adjustment frame;

The pipeline inclination adjustment frame 5 is composed of two identical 90° arc structures, each of which has a plurality of adjustment holes at equal central angles. The adjustment holes on the two arc structures are arranged correspondingly, and after installation, the distances from the plurality of adjustment holes to the pin shaft are the same, so as to ensure that after the visible pipeline support plate is rotated, the pin hole on it can be aligned with the adjustment hole at any height;

The two arc structures are respectively welded to the middle parts of the two long beams of the pipeline support base 1. The visible pipeline support plate and the three sections of transparent glass tubes are located between the two arc structures. A pair of adjustment holes in the two arc structures are connected to the pin holes of the vertical plate through the pin 6. The pin 6 is clamped on the adjustment holes at different heights of the pipeline inclination adjustment frame, so that the visible pipeline support plate can drive the visualized circulation pipeline to rise and fall along the pin shaft, thereby adjusting the inclination angle of the visualized circulation pipeline.

The two pipeline inclination adjustment frames 5 of the present invention are respectively welded to the inner side of the pipeline support base, and at the same time, a pin hole is provided on the vertical plate on one side of the visible pipeline support plate 3. Since one side of the visible pipeline support plate is fixed to the pipeline support base by a pin shaft and the other end is free, when the visible pipeline support plate is rotated so that the pin hole on the vertical plate is aligned with the adjustment holes at different height positions of the pipeline inclination adjustment frame, the pin is inserted to fix the visible pipeline support plate and keep a fixed angle between the visible pipeline support plate and the upper surface of the pipeline support base. The pipeline inclination adjustment frame is preferably provided with 7 adjustment holes at equal angle intervals along the arc direction, so that the visible pipeline support plate and the upper surface of the pipeline support base can maintain a total of 7 angles of 0, 15, 30, 45, 60, 75, and 90, and realize the cuttings migration experiment with 7 kinds of well inclination angles from 0 to 90 degrees.

Example 5

A visual cuttings transport simulation device for a drilling mud circulation pipeline without a riser, as described in Example 4, except that two bearing through holes 3-1 are provided on the U-shaped structure at one end of a visible pipeline support plate body 3-2;

As shown in FIG. 5 , the pin 2 includes a pin body 2-1, two bearings 2-2 and a nut 2-4. The pin body 2-1 is a stepped shaft, including a large shaft section with a larger shaft diameter and a small shaft section with a smaller shaft diameter. The small shaft section is provided with threads for matching with the nut.

A limiting retaining edge 2-5 is provided at the end of the large shaft section, and a retaining spring groove is provided at a certain interval in the middle. The distance between the two retaining spring grooves is equal to the distance between the two bearing through holes of the visible pipeline support plate body. A retaining spring 2-3 is provided in the retaining spring groove for fixing the retaining spring; the two bearings are flange bearings, and the large diameter end faces of the flange bearings are aligned with the retaining spring grooves, and are respectively sleeved on the large shaft section, and the axis is limited by the retaining spring;

During installation, the small shaft section of the pin shaft is inserted from the large through hole 1-1 of the pipe support base, passes through the bearings 2-2 on the two bearing through holes in turn, and finally passes through the small through hole 1-2 of the pipe support base until the limiting retaining edge 2-5 at the end of the large shaft section of the pin shaft contacts the end face of the large through hole 1-1 of the pipe support base, and finally fixed to the small shaft section of the pin shaft with a nut.

The visualization circulation pipeline of the present invention is installed on a visible pipeline support plate and is fixed and limited by four transparent glass tube supports welded on the visible pipeline support plate. At the same time, the bearing through holes of the visible pipeline support plate are connected to the large through holes and small through holes of the pipeline support base through pins to form a hinge structure.

Example 6

A visualization rock cuttings transport simulation device for a drilling mud circulation pipeline without a water riser, as described in Example 5, except that the auxiliary circulation part includes a rotary vibrating screen 15, a rock cuttings recovery barrel 12, a screw pump 13, a water screen bracket 14, a drilling fluid tank 16, a tee pipe A18, a tee pipe B19 and a tee pipe C26, the rotary vibrating screen 15 and the drilling fluid tank 16 are placed above the water screen bracket 14 and fixedly connected to the water screen bracket, the screw pump 13 is placed inside the water screen bracket, and the hose A11, the tee pipe A18, the tee pipe B19, the tee pipe C26 and the hose B27 form an auxiliary circulation pipeline, and the hose A11 is connected to the drilling fluid tank 16, and the drilling fluid tank 16 is connected to the drilling fluid tank 16. 11 connects the outlet end of the visualization circulation pipeline and the feeding port on the top of the rotary vibrating screen. The rotary vibrating screen 15 is used for solid-liquid separation. The separation port at the bottom thereof falls into the cuttings recovery barrel 12. The separation port on the right is connected to the drilling fluid tank 16. The bottom of the drilling fluid tank 16 is connected to the suction end of the screw pump. The screw pump 13 sucks the drilling fluid and pumps it into the visualization circulation pipeline at a certain flow rate.

Preferably, the three sections of transparent glass tubes are made of glass fiber reinforced plastic composite materials, hose A and hose B are flexible tubes, tee pipes A, B and C are all made of stainless steel, and the experimental fluid is drilling fluid.

Example 7

A visualization rock cuttings transport simulation device for a drilling mud circulation pipeline without a watertight riser is as described in Example 6, except that the a end of the tee pipe B19 is connected to the outlet end of the screw 13, the b end of the tee pipe B19 is connected to the inlet of the electromagnetic flowmeter 20, the c end of the tee pipe B19 is connected to the a end of the tee pipe A18, the b end of the tee pipe A18 is connected to the side opening 16-5 of the drilling fluid tank, the c end of the tee pipe A18 is connected to the side opening 22-2 of the sand tank, and a valve 17 is provided on the pipeline connecting the side opening of the drilling fluid tank and the b end of the tee pipe A18, and the sand tank can be depressurized by controlling the opening of the valve 17; the a end of the tee pipe C26 is connected to the outlet end of the electromagnetic flowmeter 20, the electromagnetic flowmeter 20 is connected to the computer 29, the b end of the tee pipe C26 is connected to the outlet end of the sand adding auger 21, and the c end of the tee pipe C26 is connected to the sand adding auger 21 through the hose B 27 is connected to the inlet end of the visualization circulation pipeline.

Example 8

A visualization rock cuttings transport simulation device for a drilling mud circulation pipeline without a riser, as described in Example 7, except that, as shown in FIG11 , the sand tank includes a sand tank body 22-1, a sand delivery port 22-3 is provided on the top of the sand tank body 22-1, a sand tank cover is welded on the upper part of the sand delivery port 22-3, and a quick connector 23 is connected to the sand tank cover, the quick connector 23 includes a male head and a female head, the male head is welded on the sand tank cover, and the male head and the female head are in a pluggable structure, and the quick connector 23 can select existing standard parts, which does not affect the implementation of the present invention;

Preferably, the sand tank 22, the sand adding auger 21 and the sand adding motor 25 are all fixed on the sand tank bracket 24, as shown in FIG12, the sand tank bracket 24 includes a steel frame body 24-1, a clamping ring 24-3 is arranged on the top of the steel frame body 24-1, a bolt hole is arranged on the clamping ring 24-3, and a sand tank clamping ring 22-5 is arranged on the sand tank, and the clamping ring 24-3 on the steel frame body has the same shape as the sand tank clamping ring 22-5, and is bolted through a plurality of bolt holes;

The upper part of the steel frame body 24-1 is threadedly connected with a connecting steel sheet A24-2 and a connecting steel sheet B 24-4, the sand adding auger 21 is welded with the connecting steel sheet A24-2 and the connecting steel sheet B 24-4, and the sand adding auger is fixed to the steel frame body by threaded connection after being welded with the connecting steel sheet A and the connecting steel sheet B on the steel frame body;

One side of the steel frame body 24 - 1 is threadedly connected to a motor base plate 24 - 5 , and the motor base plate 24 - 5 is provided with a motor mounting groove 24 - 6 for mounting the sand adding motor 25 .

Furthermore, the inlet at the top of the sand tank 22 can be opened to add sand again. After closing the valve 17, the drilling fluid and sand coexist in the sand tank 22, and the liquid pressure in the sand tank 22 is equal to the liquid pressure of the circulation pipeline.

The pressure relief principle of the sand tank is: when the screw pump is turned on, the drilling fluid will enter the sand tank through the tee pipe B and the tee pipe A. At this time, the sand inlet on the sand tank must be closed, otherwise the drilling fluid will spray out. When adding sand to the sand tank again, the pressure of the sand tank needs to be released. At this time, the valve is opened, and the drilling fluid in the sand tank will flow into the drilling fluid tank to achieve pressure relief.

Furthermore, after the cuttings are loaded into the sand tank from the sand tank cover, they will enter the sand adding auger 21 along the feeding end 22-4 at the bottom of the sand tank. The speed of the sand adding motor 25 can be adjusted to adjust the rate at which the cuttings are injected into the tee pipe C. The cuttings are carried by the drilling fluid to form a solid-liquid two-phase flow and enter the simulated part of the drilling mud pipeline without a watertight pipe through the hose B 27.

Example 9

A visualization cuttings transport simulation device for a drilling mud circulation pipeline without a riser, as described in Example 8, except that, as shown in FIG10, the drilling fluid tank includes a drilling fluid tank body 16-1, a filter baffle 16-2 is provided in the drilling fluid tank body 16-1, and the drilling fluid tank body is divided into a front chamber and a rear chamber, and two through holes 16-3 are provided on the upper portion of the filter baffle 16-2, and filter screen A is provided on the two through holes 16-3, and the drilling fluid separated from the rotary vibrating screen 15 first enters the front chamber of the drilling fluid tank, and when the drilling fluid height in the front chamber reaches the height of the two through holes 16-3, the drilling fluid passes through the filter screen A and enters the rear chamber, thereby filtering the drilling fluid fed by the rotary vibrating screen, thereby ensuring that the large drilling fluid tank contains fewer solid particles;

A side opening 16-5 of the drilling fluid tank is arranged on the side wall of the rear chamber, and a water outlet 16-4 is arranged at the bottom. The water outlet 16-4 is connected to the suction end of the screw pump. A filter screen B is arranged on the water outlet 16-4, and the aperture of the filter screen B is smaller than the aperture of the filter screen A; the water outlet is a cylindrical boss with a height of 20 cm, and the water outlet is connected to the suction end of the screw pump. The screw pump is equipped with a variable frequency motor, which can suck in the drilling fluid and pump it into the circulation pipeline at a certain flow rate.

Example 10

An experimental method for a visualization cuttings transport simulation device for a non-water riser drilling mud circulation pipeline comprises the following steps:

(1) Open valve 17 to release the pressure in sand tank 22, then add the test cuttings into sand tank 22 through quick connector 23, close valve 17, then start vibrating screen 15, start screw pump 13 to pump drilling fluid out of drilling fluid tank, and select the required drilling fluid flow rate by frequency conversion to control the speed of screw pump;

(2) The adjusting pin 6 is clamped in the adjusting holes at different height positions of the pipeline inclination adjustment frame 5, so as to adjust the visible pipeline support plate to the inclination angle required for study;

(3) Turn on the sand adding motor 25 and adjust the speed of rock cutting injection by adjusting its rotation speed, so that the rock cuttings evenly enter the visual circulation pipeline, and record the total injection amount and injection speed of the rock cuttings;

(4) Record the readings of the four pressure sensors 9 and the electromagnetic flowmeter 20, use a high-speed camera 28 to shoot and upload to a computer 29, which records and displays the shape, trajectory, thickness and time of complete removal of the cuttings;

(5) By adjusting the displacement of the screw pump 13 and repeating steps (1) to (4), the cuttings migration of the drilling fluid at different drilling fluid return rates in riser-free drilling can be simulated, and the electromagnetic flowmeter readings and pressure sensor readings are recorded. At the same time, the inlet cuttings type, inlet cuttings size, inlet cuttings shape, inlet cuttings volume fraction, pipeline inclination angle, pipeline shape, cuttings movement trajectory, cuttings deposition bed and cuttings restart are recorded, and the influence of different drilling fluid flow rates on the cuttings migration in the pipe is analyzed;

(6) adjusting the cuttings injection speed by controlling the rotation speed of the sand adding motor 25 and repeating steps (1) to (4) to simulate the cuttings migration of the drilling fluid under the conditions of different cuttings generation amounts at different drilling speeds in riser-free drilling, recording the electromagnetic flowmeter readings and the pressure sensor readings, and recording the inlet cuttings type, inlet cuttings size, inlet cuttings shape, inlet cuttings volume fraction, pipeline inclination angle, pipeline shape, cuttings movement trajectory, cuttings deposition bed and cuttings restart, and analyzing the influence of different cuttings generation amounts on the cuttings migration in the pipe;

(7) By controlling the pin 6 to be stuck in the adjustment holes at different height positions of the pipeline inclination adjustment frame 5 and repeating steps (1) to (4), the inclination angle of the visible pipeline support plate can be adjusted, thereby driving the visual circulation pipeline to rise and fall, and simulating the cuttings migration of the drilling fluid at different pipeline inclination angles in watertight pipe drilling, recording the electromagnetic flowmeter readings and pressure sensor readings, and at the same time recording the inlet cuttings type, inlet cuttings size, inlet cuttings shape, inlet cuttings volume fraction, pipeline inclination angle, pipeline shape, cuttings movement trajectory, cuttings deposition bed and cuttings restart, and analyzing the influence of different pipeline inclination angles on the cuttings migration in the pipe;

(8) By changing the type, size and shape of the cuttings loaded into the sand tank 22 and repeating steps (1) to (4), the cuttings migration of the drilling fluid under different cuttings in the watertight pipe drilling can be simulated, and the electromagnetic flow meter reading and the pressure sensor reading are recorded. At the same time, the inlet cuttings type, inlet cuttings size, inlet cuttings shape, inlet cuttings volume fraction, pipeline inclination angle, pipeline shape, cuttings movement trajectory, cuttings deposition bed and cuttings restart are recorded, and the influence of different cuttings on the cuttings migration in the pipe is analyzed;

(9) By replacing transparent glass tubes of different shapes and repeating steps (1) to (4), the cuttings migration of drilling fluid under different pipe shapes in watertight pipe drilling can be simulated, and the electromagnetic flowmeter readings and pressure sensor readings are recorded. At the same time, the inlet cuttings type, inlet cuttings size, inlet cuttings shape, inlet cuttings volume fraction, pipe inclination angle, pipe shape, cuttings movement trajectory, cuttings deposition bed and cuttings restart are recorded, and the influence of different pipe shapes on the cuttings migration in the pipe is analyzed;

(10) After the experiment, turn off the sand adding motor first, wait until the rotary vibrating screen has separated the cuttings from the drilling fluid, then turn off the screw pump, then turn off the rotary vibrating screen, and pour the cuttings in the cuttings recovery bucket into the cuttings recovery area for reprocessing for reuse.

The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims (6)

1. The visual rock debris migration simulation device for the riser-free drilling mud circulation pipeline is characterized by comprising a mud circulation pipeline simulation part, an auxiliary circulation part, a sand adding part and a data detection and processing part;

the slurry circulation pipeline simulation part comprises a pipeline support base, a visual pipeline support plate, three sections of transparent glass pipes and a pipeline inclination angle adjusting frame, wherein the three sections of transparent glass pipes are connected with each other to form a visual circulation pipeline, the visual circulation pipeline is fixed on the visual pipeline support plate, the visual pipeline support plate is arranged on the pipeline support base, and the inclination angle of the visual pipeline support plate is adjusted by means of the pipeline inclination angle adjusting frame; one end of the visual circulating pipeline is connected with a hose A, the other end of the visual circulating pipeline is connected with a hose B, and pressure sensors are arranged at the interconnection positions of the hose A, the three sections of transparent glass tubes and the hose B and are used for measuring the pressures at different positions;

One end of the auxiliary circulation part is connected with the hose A, the other end of the auxiliary circulation part is connected with the hose B, and the auxiliary circulation part is used for providing drilling fluid for the visual circulation pipeline, separating the drilling fluid passing through the visual circulation pipeline from rock fragments and recovering experimental rock fragments;

The sand adding part comprises a sand tank, a sand adding auger and a sand adding motor, wherein a feeding end is arranged at the bottom of the sand tank and is connected with the feeding end of the sand adding auger, and rock scraps in the sand tank are conveyed to the sand adding auger Long Chuliao end under the action of the sand adding motor after entering the sand adding auger and are used for providing rock scraps with different throwing rates;

The data detection and processing part comprises a high-speed camera and a computer, wherein the high-speed camera is used for shooting the real-time state of the visual circulating pipeline and transmitting the real-time state to the computer, and the computer is connected with a plurality of pressure sensors to acquire pressure information in real time;

The auxiliary circulation part comprises a rotary vibration sieve, a rock debris recycling bin, a screw pump, a water sieve support, a drilling fluid tank, a three-way pipe A, a three-way pipe B and a three-way pipe C, wherein the rotary vibration sieve and the drilling fluid tank are arranged above the water sieve support and are fixedly connected with the water sieve support, the screw pump is arranged inside the water sieve support, a hose A, the three-way pipe B, the three-way pipe C and the hose B form an auxiliary circulation pipeline, the hose A is connected with an outlet end of the visual circulation pipeline and a feeding port at the top of the rotary vibration sieve, the rotary vibration sieve is used for solid-liquid separation, a separating port at the lower part of the rotary vibration sieve falls into the rock debris recycling bin, a separating port at the right side of the rotary vibration sieve is connected with the drilling fluid tank, the bottom of the drilling fluid tank is connected with a suction end of the screw pump, and the screw pump sucks and pumps the drilling fluid into the visual circulation pipeline;

The three sections of transparent glass tubes are made of glass fiber reinforced plastic composite materials, the hose A and the hose B are flexible tubes, the three-way pipe A, the three-way pipe B and the three-way pipe C are made of stainless steel, and experimental fluid is drilling fluid;

The end a of the three-way pipe B is connected with the outlet end of the screw pump, the end B of the three-way pipe B is connected with the inlet of the electromagnetic flowmeter, the end c of the three-way pipe B is connected with the end a of the three-way pipe A, the end B of the three-way pipe A is connected with the side opening of the drilling fluid tank, the end c of the three-way pipe A is connected with the side opening of the sand tank, a valve is arranged on the connecting pipeline between the side opening of the drilling fluid tank and the end B of the three-way pipe A18, and the sand tank can be decompressed by controlling the opening of the valve; the end a of the three-way pipe C is connected with the outlet end of the electromagnetic flowmeter, the electromagnetic flowmeter is connected with the computer, the end B of the three-way pipe C is connected with the outlet end of the sand-adding auger, and the end C of the three-way pipe C is connected with the inlet end of the visual circulating pipeline through a hose B;

the sand tank comprises a sand tank body, a sand conveying opening is formed in the top of the sand tank body, a sand tank cover is welded to the upper portion of the sand conveying opening, a quick connector is connected to the sand tank cover, the quick connector comprises a male head and a female head, the male head is welded to the sand tank cover, and a pluggable structure is arranged between the male head and the female head;

The sand tank, the sand feeding auger and the sand feeding motor are all fixed on a sand tank support, the sand tank support comprises a steel frame body, a clamping ring is arranged at the top of the steel frame body, a bolt hole is formed in the clamping ring, a sand tank clamping ring is arranged on the sand tank, the clamping ring on the steel frame body is identical to the sand tank clamping ring in shape, and the clamping ring and the sand tank clamping ring are connected through a plurality of bolt holes;

The upper part of the steel frame body is in threaded connection with a connecting steel sheet A and a connecting steel sheet B, and a sand adding auger is welded with the connecting steel sheet A and the connecting steel sheet B;

One side of the steel frame body is connected with a motor seat board in a threaded manner, and a motor mounting groove is formed in the motor seat board and used for mounting a sand adding motor;

The drilling fluid tank comprises a drilling fluid tank main body, a filtering baffle plate is arranged in the drilling fluid tank main body, the drilling fluid tank main body is divided into a front cavity and a rear cavity, two through holes are formed in the upper portion of the filtering baffle plate, a filtering screen A is arranged on the two through holes, drilling fluid separated from a rotary vibrating screen firstly enters the front cavity of the drilling fluid tank, and when the drilling fluid in the current cavity reaches the height of the two through holes, the drilling fluid enters the rear cavity through the filtering screen A, so that the filtration of the drilling fluid fed by the rotary vibrating screen is realized;

The side wall of the rear cavity is provided with a side opening of the drilling fluid tank, the bottom of the rear cavity is provided with a water outlet which is connected with the suction end of the screw pump, the water outlet is provided with a filter screen B, and the aperture of the filter screen B is smaller than that of the filter screen A; the water outlet is a cylindrical boss with the height of 20 cm.

2. The visual rock debris migration simulation device of the riser-free drilling mud circulation pipeline according to claim 1, wherein three sections of transparent glass pipes are connected through two metal connecting rings A, each metal connecting ring A is a hollow cylinder, external threads are formed at two ends of each metal connecting ring A, and the metal connecting rings A are matched with the internal threads at the end parts of the transparent glass pipes to realize connection;

the visual circulating pipeline is connected with the hose A and the hose B through a metal connecting ring B, the metal connecting ring B is also a hollow cylinder, one end of the metal connecting ring B is provided with external threads which are matched with the internal threads at the end part of the transparent glass tube, and the other end of the metal connecting ring B is directly connected with the hose A or the hose B;

threaded holes are formed in the middle outer walls of the two metal connecting rings A and the two metal connecting rings B and are used for installing pressure sensors in a spiral mode so as to detect liquid flow pressures at different positions of a visual circulating pipeline in real time;

the three sections of transparent glass tubes are identical or different in shape, and the transparent glass tubes are straight tubes, equal-diameter horizontal bent glass tubes, equal-diameter local vertical upward bent glass tubes or equal-diameter local vertical downward bent glass tubes.

3. The visual rock debris migration simulation device for the riser-free drilling mud circulation pipeline according to claim 1, wherein the whole pipeline supporting base is of a frame structure consisting of two long cross beams and three pairs of supporting legs, and one end of the pipeline supporting base is connected with one end of a visual pipeline supporting plate through a pin shaft;

Two through holes with different diameters are formed in the two supporting legs at one end of the pipeline supporting base, the through holes are large through holes and small through holes respectively, the large through holes are used for being filled with pin shafts, and the small through holes are used for fixing the pin shafts.

4. The visual rock debris migration simulation device for the riser-free drilling mud circulation pipeline according to claim 3, wherein the visual pipeline support plate comprises a visual pipeline support plate main body, the visual pipeline support plate main body is of an inverted U-shaped structure, a plurality of transparent glass tube supports are welded on the upper surface of the visual pipeline support plate main body, and a fixing hole is formed in each transparent glass tube support and used for fixing a transparent glass tube;

The upper surface of the main body of the visible pipeline supporting plate is also welded with a vertical plate, and the vertical plate is provided with a pin hole for being matched with the pipeline inclination angle adjusting frame;

The pipeline inclination angle adjusting frame consists of two identical arc structures similar to 90 degrees, a plurality of adjusting holes are distributed on each arc structure at equal circle center angles, and the adjusting holes on the two arc structures are correspondingly arranged;

The two circular arc structures are welded at the middle parts of the two long cross beams of the pipeline supporting base respectively, the visual pipeline supporting plate and the three-section transparent glass tube are located between the two circular arc structures, one pair of adjusting holes of the two circular arc structures is connected with the pin holes of the vertical plate through the pin, and the two circular arc structures are clamped on the adjusting holes of different heights of the pipeline inclination adjusting frame through the pin holes, so that the visual pipeline supporting plate can drive the visual circulating pipeline to lift along the pin shaft, and the inclination angle of the visual circulating pipeline is adjusted.

5. The visual debris migration simulation device for the riser-free drilling mud circulation pipeline according to claim 4, wherein two bearing through holes are formed in the U-shaped structure at one end of the main body of the visual pipeline support plate;

The pin shaft comprises a pin shaft main body, two bearings and a nut, wherein the pin shaft main body is a step-shaped shaft and comprises a large shaft section with a larger shaft diameter and a small shaft section with a smaller shaft diameter, and the small shaft section is provided with threads for being matched with the nut;

the end part of the large shaft section is provided with a limiting flange, the middle part is provided with a clamp spring groove at a certain distance, the distance between the two clamp spring grooves is equal to the distance between the two bearing through holes of the main body of the visible pipeline supporting plate, and the clamp spring groove is internally provided with a clamp spring for fixing the clamp spring; the two bearings are flange bearings which are respectively sleeved on the large shaft section and are used for limiting the axis by virtue of the snap springs;

During installation, the small shaft section is inserted from the large through hole of the pipeline supporting base, sequentially passes through the bearings on the two bearing through holes, finally passes out from the small through hole of the pipeline supporting base until the limit flange at the end part of the large shaft section in the pin shaft is contacted with the end surface of the large through hole of the pipeline supporting base, and finally is fixed on the small shaft section of the pin shaft by using a nut.

6. A method of testing a visual cuttings migration simulation apparatus for a riser-less drilling mud circulation line of claim 5, comprising the steps of:

(1) Opening a valve to enable the sand tank to finish pressure relief, adding rock scraps for testing into the sand tank through a quick connector, closing the valve, opening a rotary vibration sieve, opening a screw pump to pump drilling fluid out of the drilling fluid tank, and selecting required drilling fluid flow by controlling the rotating speed of the screw pump;

(2) The adjusting pin bolts are clamped in adjusting holes at different height positions of the pipeline inclination angle adjusting frame, so that the inclination angle of the visual pipeline supporting plate to be researched is adjusted;

(3) Starting a sand adding motor, adjusting the rock debris injection speed by adjusting the rotating speed of the sand adding motor, enabling the rock debris to uniformly enter a visual circulating pipeline, and recording the total injection quantity and the injection speed of the rock debris;

(4) Recording four pressure sensor readings and electromagnetic flowmeter readings, shooting by using a high-speed camera, uploading the readings to a computer, and recording and displaying the form, track and thickness of the rock debris and the time for completely removing the rock debris by the computer;

(5) Through adjusting the discharge capacity of the screw pump, repeating the steps (1) to (4), simulating the rock debris migration condition of drilling fluid under different return speeds of drilling fluid in the well drilling without a water isolation pipe, recording the readings of an electromagnetic flowmeter and the readings of a pressure sensor, and simultaneously recording the inlet rock debris type, the inlet rock debris size, the inlet rock debris shape, the inlet rock debris volume fraction, the pipeline inclination angle, the pipeline shape, the rock debris movement track, the rock debris deposition bed and the rock debris restarting condition, and analyzing the influence of different drilling fluid flow on the rock debris migration in the pipeline;

(6) The rock debris injection speed is adjusted by controlling the rotating speed of the sand adding motor, the steps (1) to (4) are repeated, the rock debris migration condition of drilling fluid under the condition that different rock debris generation amounts are generated by different drilling speeds in the drilling without a water isolation pipe can be simulated, the readings of an electromagnetic flowmeter and the readings of a pressure sensor are recorded, and meanwhile, the inlet rock debris type, the inlet rock debris size, the inlet rock debris shape, the inlet rock debris volume fraction, the pipeline inclination angle, the pipeline shape, the rock debris movement track, the rock debris deposition bed and the rock debris restarting condition are recorded, so that the influence of different rock debris generation amounts on the rock debris migration in the pipe is analyzed;

(7) The adjusting holes at different height positions of the pipeline inclination angle adjusting frame are clamped by the control pins, the steps (1) to (4) are repeated, the inclination angle of the visible pipeline supporting plate can be adjusted, so that the visible circulating pipeline is driven to lift, the rock chip migration condition of drilling fluid under different pipeline inclination angles in the non-riser drilling can be simulated, the readings of the electromagnetic flowmeter and the pressure sensor are recorded, the inlet rock chip type, the inlet rock chip size, the inlet rock chip shape, the inlet rock chip volume fraction, the pipeline inclination angle, the pipeline shape, the rock chip movement track, the rock chip deposition bed and the rock chip restarting condition are recorded, and the influence of different pipeline inclination angles on the rock chip migration in the pipeline is analyzed;

(8) By changing the type, size and shape of the cuttings loaded into the sand tank and repeating the steps (1) to (4), the cuttings migration condition of drilling fluid under different cuttings in the well drilling without a riser can be simulated, the readings of the electromagnetic flowmeter and the pressure sensor are recorded, and meanwhile, the inlet cuttings type, the inlet cuttings size, the inlet cuttings shape, the inlet cuttings volume fraction, the pipeline inclination angle, the pipeline shape, the cuttings movement track, the cuttings deposition bed and the cuttings restarting condition are recorded, and the influence of different cuttings on the cuttings migration in the pipe is analyzed;

(9) Through changing transparent glass tubes with different shapes, repeating the steps (1) to (4), simulating the rock debris migration condition of drilling fluid under different pipeline shapes in the well drilling without the water isolation tube, recording the readings of the electromagnetic flowmeter and the pressure sensor, simultaneously recording the inlet rock debris type, the inlet rock debris size, the inlet rock debris shape, the inlet rock debris volume fraction, the pipeline inclination angle, the pipeline shape, the rock debris movement track, the rock debris deposition bed and the rock debris restarting condition, and analyzing the influence of different pipeline shapes on the rock debris migration in the pipeline;

(10) After the experiment is finished, the sand adding motor is firstly closed, the screw pump is closed after the rotary vibration sieve separates the rock scraps from the drilling fluid, then the rotary vibration sieve is closed, and the rock scraps in the rock scraps recycling bin are poured into the rock scraps recycling position for reprocessing so as to be reused.