CN108226162B - Visual evaluation system and visual evaluation method for hydrate generation blocking law in screen - Google Patents
Visual evaluation system and visual evaluation method for hydrate generation blocking law in screen Download PDFInfo
- Publication number
- CN108226162B CN108226162B CN201810196986.2A CN201810196986A CN108226162B CN 108226162 B CN108226162 B CN 108226162B CN 201810196986 A CN201810196986 A CN 201810196986A CN 108226162 B CN108226162 B CN 108226162B
- Authority
- CN
- China
- Prior art keywords
- screen
- gas
- pressure
- hydrate
- temperature
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
- G01N21/85—Investigating moving fluids or granular solids
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Information Retrieval, Db Structures And Fs Structures Therefor (AREA)
Abstract
The invention provides a visual evaluation system for a blocking law of hydrate generation in a screen and a test method thereof, wherein an experimental system for a secondary generation, enrichment and blocking law of hydrate in a screen mesh comprises the following steps: the device comprises a reaction kettle, a gas-liquid mixing and conveying coil pipe, a high-speed camera, a data acquisition and processing module and the like. The testing method is based on the system, and by adjusting the cooling mode, controlling the temperature and pressure conditions and the gas-liquid ratio conditions, the three-dimensional pattern of the blockage generated by the hydrate secondary in the screen mesh is simulated, and the system can provide basic data for calculating the additional skin coefficient of the sand control of the bottom screen of the well under different well body structural conditions (vertical well, horizontal well or multi-branch hole) of the natural gas hydrate exploitation well and preparing a precise pressure-reducing and temperature-controlling scheme, and provides powerful support for the sand production management system of the natural gas hydrate exploitation well.
Description
Technical Field
The invention belongs to the field of natural gas hydrate exploitation, relates to the technical direction of evaluation of the degree of reduction of the productivity of a hydrate well caused by blockage of a well bottom mechanical screen pipe type medium in the process of exploitation of marine hydrates, and particularly relates to an evaluation system and an evaluation method of a secondary generation blockage rule of the hydrate in a screen pipe mesh under actual exploitation conditions.
Background
A large amount of natural gas hydrate resources are reserved in the surrounding sea areas of China, and the successful exploitation of the natural gas hydrate resources is helpful for improving the energy structure of China. In 2017, china develops first sea area natural gas hydrate trial production for 60 days in a muddy powder sand type reservoir of the sea area of the south China sea god fox, obtains 30.9-thousand-square cumulative gas yield, and obtains two actual records of gas production duration and cumulative gas yield, so that China is in the leading position in international competition for natural gas hydrate resource development.
With the continuous development of test production and the continuous deep understanding of test production phenomena, the applicant discovers some engineering geological phenomena which are not considered originally, and has great trouble on the industrialization process of natural gas hydrate. Such as analysis of the working condition of the sand control medium, secondary generation of hydrate in the stratum and the pipeline, etc. The applicant has further studied to find that: the increase of the additional surface coefficient of the sand control screen pipe in the natural gas hydrate exploitation process is not only caused by the blockage of the argillaceous particles, but also is more important to the increase of the additional pressure drop caused by the secondary generation of hydrate on the surface of the sand control screen pipe, particularly on the surface of a screen under certain pressure drop, gas production water and bottom hole temperature conditions.
The conventional evaluation method for the productivity influence caused by the sand control medium mainly considers the blockage of the argillaceous particles, and the method can not completely meet the requirement of risk evaluation of the natural gas hydrate exploitation well; the evaluation of the risk of blocking a screen pipe in a hydrate exploitation well, a blocking rule and the influence of the blocking rule on productivity must comprehensively consider the superposition effects of two aspects of muddy blocking and hydrate secondary generation blocking. The method for evaluating the muddy blockage in the conventional oil gas can be used as the former, but the latter is a novel problem unique to a natural gas hydrate exploitation well, and the research on the method at home and abroad is blank at present. Therefore, the invention aims to provide a visual evaluation device and a visual evaluation method for the blocking law of hydrate generation in a screen, so as to solve the bottleneck faced by the evaluation of a well bottom screen of a natural gas hydrate exploitation well at present.
Disclosure of Invention
Aiming at the problem that the conventional evaluation method for the productivity influence caused by the sand control medium cannot meet the requirement of risk evaluation of a natural gas hydrate exploitation well at present, the invention provides a visual experimental device and method for observing hydrate secondary generation, enrichment and blocking rules at two sides of a screen mesh of a sand control screen in real time, thereby providing basic data for calculation of additional skin coefficients of sand control of a screen at the bottom of a well (a vertical well, a horizontal well or a multi-branch hole) and formulation of an accurate pressure-reduction temperature control scheme under different well body structural conditions of the natural gas hydrate exploitation well and providing powerful support for a sand production management system of the natural gas hydrate exploitation well.
The invention is realized by adopting the following technical scheme:
the invention provides a visual evaluation system for a blocking rule of hydrate generation in a screen, which comprises the following components: the reaction kettle is arranged on the rotary support in the low-temperature constant-temperature box and comprises a sapphire kettle body, a screen assembly positioned in the kettle body, and an outlet end cover and an inlet end cover which are arranged at two ends of the kettle body, wherein the outer sides of the two end covers are connected with high-pressure metal pipes; the gas-liquid mixed delivery coil is arranged in the closed low-temperature water bath box, the high-speed camera is arranged in the low-temperature constant-temperature box and is opposite to the reaction kettle, so as to capture video data in the sapphire kettle body and obtain the flowing type change condition around the screen when the secondary generation blockage of hydrate in the screen occurs; and the data acquisition and processing module is used for acquiring and processing the pump speed data, the gas-liquid ratio, the system temperature, the system pressure and the video data of the high-speed camera.
Further, the screen assembly comprises a screen mesh and a screen mesh support, the screen mesh is a screen used for an actual well bottom screen, the screen mesh is mounted on the screen mesh support and is in a long cylinder shape and integrally and horizontally arranged, the screen mesh support comprises a circular screen support bottom plate, a screen support joint and 6-10 ribs positioned on the same cylindrical surface, one end of each rib is fixed on the circular screen support bottom plate, the other end of each rib is fixed on the screen support joint, and the diameter of the screen support bottom plate is equal to that of a high-pressure metal pipe outside an outlet end cover.
Further, the inner side of the reaction kettle inlet end cover is connected with a horn inlet port, the inlet port comprises a horn outer liner and a horn inner liner, a sealing bearing is adopted between the horn outer liner and the horn inner liner, the outer edge of the bearing is in interference fit with the inner edge of the outer liner, a connecting cock is fixed on the inner edge of the bearing, the connecting cock is a conical surface steel block, the connecting cock is welded with the upper part of the horn inner liner, a runner which is spirally distributed is arranged in the connecting cock, a runner outlet is arranged on the side wall of the connecting cock, and the inlet is arranged above the connecting cock.
Further, the outer diameter of the lower edge of the horn liner is the same as the diameter of the bottom plate of the screen support, pressure measuring holes are respectively formed in the high-pressure metal pipes outside the inlet end cover and the outlet end cover, a differential pressure gauge is connected between the two pressure measuring holes, the pressure measuring holes in the inlet end cover penetrate into the middle part of the reaction kettle through the pressure guiding pipe, the outlet end of the gas-liquid mixing conveying coil pipe is connected with a vacuum pump through a three-way switching valve, and in addition, the gas-liquid mixing conveying coil pipe also comprises a water bath refrigeration cabinet for cooling the closed low-temperature water bath box.
Further, the inner diameter of the sapphire kettle body is 30mm, and the length is 150mm; the length of the screen mesh is 100mm, and the diameter of the bottom plate of the screen bracket is 20mm; the effective length of the gas-liquid mixing and conveying coil pipe in the closed low-temperature water bath box is 30m.
The invention further provides a visual evaluation method for the blocking law of hydrate generation in the screen, which comprises the following steps:
(1) Determining a simulated well type, and determining a reaction kettle inclination angle required by a hydrate blockage simulation evaluation experiment in a screen according to the well type (vertical well, horizontal well or inclined well) simulated by actual needs, wherein the reaction kettle, a vacuum pump, a gas-liquid mixed conveying coil, a methane gas cylinder, a water supply pump, a circulating pump, a water bath refrigeration cabinet and a data acquisition module are sequentially connected;
(2) Vacuumizing, namely vacuumizing the whole system;
(3) Pressurizing a gas-liquid mixing conveying coil pipe, injecting quantitative methane gas and quantitative water into the coil pipe according to a set gas-water ratio, and pressurizing to a set pressure value;
(4) The back suction circulation is carried out, so that a gas-water mixture in the gas-liquid mixing and conveying coil is sucked into the reaction kettle under the action of negative pressure, and then a circulating pump is started for fixed pump frequency circulation;
(5) Starting collection and cooling simulation: synchronously with the step (4), acquiring video images of the high-speed camera, pressure difference, temperature and pressure changes along with time in real time in the fixed pump frequency circulation process; starting a water bath refrigeration cabinet and a low-temperature constant-temperature box, setting the same temperature value, slowly cooling the system, and observing a critical temperature condition value formed by starting enrichment of hydrate on the surface of the screen;
(6) Selecting a cooling mode and simulating blockage: synchronously with the step (4), injecting methane gas and water into the gas-liquid mixing and conveying coil pipe according to a proportion, maintaining the pressure at a preset value, selecting two modes of constant temperature continuous circulation and continuous slow cooling circulation according to actual requirements when the temperature condition reaches a critical temperature condition value at which hydrate on the surface of the screen is enriched and formed, and observing a change rule of a hydrate blocking rule in the screen along with time under a constant temperature condition or a hydrate enrichment blocking rule in the screen under a temperature continuous reduction environment;
(7) Adjusting a preset pressure value and a gas-liquid ratio, and performing cyclic simulation: the preset pressure value or the gas-liquid ratio condition of the system is adjusted, the steps (2) to (6) are repeated, and a three-dimensional distribution plate of the critical condition, in which the hydrate in the screen is enriched and blocked to a certain extent, are obtained through multiple tests, wherein the temperature, the pressure and the gas-water ratio are respectively the hydrate in the screen of the coordinate axes;
(8) Stopping simulation: when the pressure difference at both sides of the screen is raised by more than 10 times of the high initial pressure difference, the experiment is stopped.
And (3) continuously injecting methane gas and water into the gas-liquid mixed delivery coil pipe when the flow pattern of the fixed pump frequency circulating in the whole pipeline is stable, and compensating for the pressure reduction of the gas-liquid mixed delivery coil pipe caused by the back suction of the reaction kettle.
Compared with the prior art, the invention has the advantages and positive effects that:
according to the invention, the generation and enrichment conditions of the natural gas hydrate in the screen medium under different temperature and pressure-flow working conditions can be visually observed, a calculation model of the additional skin coefficient response rule of the sand control medium at the bottom of the well caused by the secondary generation of the hydrate can be established by performing an indoor simulation experiment, a basis is provided for evaluating the influence rule of the sand control medium productivity of the natural gas hydrate exploitation well, and a help is provided for the establishment of a well bottom depressurization scheme of the natural gas hydrate exploitation well for preventing the secondary generation of the hydrate in the screen pipe from becoming one of optimization targets.
According to the invention, through the multi-layer structural design of the screen mesh and the equal-diameter design between the screen mesh support bottom plate and the high-pressure metal pipe on the reaction kettle outlet end cover, the pressure difference between the inlet and the outlet of the reaction kettle, which is measured in the experimental process, can be approximately regarded as the pressure difference of two sides of the screen mesh, so that the difficulty of drilling and measuring pressure on the surface of the sapphire kettle is effectively avoided.
The structural design of the horn inlet port prevents the direct impact of the flowing-in gas-liquid two-phase fluid on the screen mesh support, effectively protects the sealing between the reaction kettle and the screen mesh support, and on the other hand, the horn inlet port is more important to promote the gas-liquid two-phase fluid to flow into the screen in a manner of being perpendicular to the screen mesh, so that simulated radial flow is formed, and the real bottom hole flow condition is simulated as much as possible.
Drawings
FIG. 1 is a schematic diagram of a visual evaluation device for the blocking law of hydrate formation in a screen according to an embodiment of the invention;
FIG. 2 is a schematic diagram of a simulated reaction kettle for screen hydrate blockage according to an embodiment of the invention;
FIG. 3 is a schematic view of a screen assembly according to an embodiment of the present invention;
FIG. 4 is a schematic side view of a screen assembly according to an embodiment of the present invention;
FIG. 5 is a schematic view of a horn inlet according to an embodiment of the present invention;
FIG. 6 is a schematic top view of a horn inlet according to an embodiment of the present invention;
FIG. 7 is a schematic view of a cock structure according to an embodiment of the present invention;
FIG. 8 is a flow chart of a method for simulating the regular plugging of hydrate formation in a screen according to an embodiment of the invention.
In the above figures: 1. screen hydrate plugs the simulated reaction kettle; 2. a low temperature incubator; 3. a vacuum pump; 4. sealing a low-temperature water bath box; 5. a gas-liquid mixing and conveying coil pipe; 6. a methane cylinder; 7. a water bath refrigerator; 8. a water supply pump; 9. a circulation pump; 10. a high-speed camera; 11. a data acquisition module; 12. an inlet end cover of the reaction kettle; 13. a sapphire kettle body; 14. a connecting clamp; 15. an outlet end cover of the reaction kettle; 16. a high pressure metal tube; 17. a high pressure hose; 18. a rotating bracket; 19. a horn inlet; 20. a screen mesh; 21. sealing rubber rings; 22. ribs of a screen mesh support; 23. a screen support base plate; 24. a screen support joint; 25. connecting a cock; 26. a pressure guiding pipe; 19-1, connecting threads of the horn inlet; 19-2, a horn outer liner; 19-3, horn liner; 19-3-1, horn lining flow guide channels; 19-3-2, the lower edge of the horn liner; 19-3-horn lining upper bearings; 20-1, connecting the internal flow passage of the cock; 25-1, connecting the cock internal flow passage; f1, F2, F3, F4, high pressure ball valves; FC1, three-way conversion ball valve; t1, a temperature measuring point; p1, P2, pressure measurement point.
Detailed Description
In order that the above objects, features and advantages of the invention will be more readily understood, a further description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings.
In the first embodiment, the present embodiment provides a visual evaluation system for blocking law generated by hydrate in a screen, referring to fig. 1, including a reaction kettle 1, a vacuum pump 3, a gas-liquid mixing and conveying coil 5, a methane gas cylinder 6, a water supply pump 8, a circulating pump 9, a water bath refrigeration cabinet 7, a high-speed camera 10 and a data acquisition module 11.
Referring to fig. 2 and 3, the reaction vessel includes: the device comprises a sapphire kettle body 13, a reaction kettle inlet end cover 12, a connection clamp 14, a reaction kettle outlet end cover 15, a rotary support 18, a horn inlet 19, a screen assembly, a sealing rubber ring 21, a screen mesh support, a high-pressure metal pipe 16 and a high-pressure hose 17 which are connected with the screen mesh support. The sapphire kettle body 13 is in double sealing with an inlet end cover 12 and an outlet end cover 15 of the reaction kettle by adopting an end sealing rubber ring and a side wall sealing rubber ring, and the inlet end cover 12 and the outlet end cover 15 of the reaction kettle are connected and fixed through a metal pull rod type connecting clamp 14; the outer side of the inlet end cover 12 of the reaction kettle is connected with a high-pressure metal pipe 16 by a clamping sleeve pressing cap, and the inner side is connected with a horn inlet 19; the outer side of the reaction kettle outlet end cover 15 is connected with a high-pressure metal pipe 16 through a sealing rubber ring, the inner side of the reaction kettle outlet end cover 15 is connected with a screen mesh support with the same diameter as the high-pressure metal pipe, and one or more layers of screen meshes are wrapped on the periphery of the screen mesh support; the whole reaction kettle is arranged on the rotary support, and the angle of the reaction kettle can be adjusted by the rotary support according to actual demands, so that simulation experiments can be carried out at any inclination angle.
The inlet end of the gas-liquid mixed transportation coil pipe 5 is sequentially connected with a circulating pump 9 and a high-pressure metal pipe 16 on an outlet end cover 15 of the reaction kettle through a high-pressure hose 17, the middle part of the gas-liquid mixed transportation coil pipe 5 is respectively connected with a water supply pump 8 and a methane gas cylinder 6 through a high-pressure ball valve, the outlet end of the gas-liquid mixed transportation coil pipe 5 is connected with a vacuum pump 3 and the high-pressure metal pipe 16 on an inlet end cover 12 of the reaction kettle through a three-way conversion ball valve FC1, and the gas-liquid mixed transportation coil pipe 5 is arranged in a closed low-temperature water bath tank 4.
As shown in fig. 1, a high-speed camera 10 is installed in the interior of the cryostat tank 2 opposite to the reaction kettle for capturing video data in the sapphire kettle. The data acquisition and processing module 11 is used for acquiring and processing the pump speed data of the circulating pump, the gas-liquid ratio, the system temperature T1, the pressures P1 and P2 and the video data of the high-speed camera.
The screen assembly of this embodiment is shown in fig. 3 and 4, and includes a screen mesh 20, where the screen mesh 20 is mounted on a screen mesh support and is in a long tubular shape, and is wholly horizontal, and the screen mesh support includes a circular screen support bottom plate 23, a screen support joint 24, and 6 ribs 22 (the number of specific ribs is determined according to actual needs) located on the same cylindrical surface, one end of each rib 22 is fixed on the circular screen support bottom plate 23, and the other end is fixed on the screen support joint 24, where the diameter of the screen support bottom plate 23 is equal to the diameter of the high-pressure metal tube 16 outside the outlet end cap. Wherein the screen support bottom plate 23 is a steel sheet, the screen support joint 24 is a steel ring with the same diameter as the screen support bottom plate 23, and is connected with the outlet end cover 15 of the reaction kettle. The screen mesh 20 is wound on the screen mesh support, and the winding number of the screen mesh 20 on the screen mesh support is determined according to the number of screen layers used in an actual hydrate exploitation well. The equal diameter design of the bottom plate 23 of the screen support and the high-pressure metal pipe 16 outside the outlet end cover in this embodiment reduces the reducing throttling effect in the flowing process of the gas-liquid mixture, thus reducing the flowing resistance when the gas-liquid flows from the inside of the screen mesh support to the high-pressure metal pipe, and avoiding the adverse effect on the flowing in the narrow space when the outlet end cover stretches into the pressure guiding pipe to the inside of the screen mesh support, so that the pressure of the outlet end of the reaction kettle can be approximately considered to be equal to the average pressure inside the screen mesh support, and the pressure of the outer side of the screen mesh is approximately equal to the pressure inside the inlet end cover of the reaction kettle. Therefore, the principle is adopted to convert the pressure difference at two sides of the long cylindrical installed screen assembly into the pressure difference at two ends of the inlet and outlet of the reaction kettle, and the error between the measured pressure difference and the actual pressure difference at two sides of the actual screen in the conventional design is effectively reduced.
Referring to fig. 5-7, the horn inlet 19 of the present embodiment is a typical "two-story" structure, shaped like two horns stacked. The loudspeaker comprises a loudspeaker outer liner 19-2 and a loudspeaker inner liner 19-3, wherein the outer diameter of the lower edge 19-3-2 of the loudspeaker inner liner is the same as the diameter of a screen bracket bottom plate 23, a sealing bearing 19-3-3 is adopted between the loudspeaker outer liner 19-2 and the loudspeaker inner liner 19-3, the outer edge of the bearing is in interference fit and fixed with the inner edge of the outer liner, the inner edge of the bearing is fixed with a connecting cock 25, the connecting cock 25 is a conical steel block, the connecting cock 25 is welded with the upper part of the inner liner, an inner runner 25-1 which is spirally distributed in the connecting cock is arranged on the inner side wall of the connecting cock, and an inlet is right above the connecting cock. The horn liner is provided with a diversion flow passage 19-3-1 which is spirally distributed from top to bottom. When the fluid in the upper high-pressure metal pipe 16 enters the internal flow passage 25-1 of the connecting cock, the horn liner 19-9 is driven to rotate under the action of centrifugal force, and the fluid flows out of the internal flow passage 25-1 and is thrown into the diversion flow passage 19-3-1 and then is thrown to the inner edge of the reaction kettle. The connecting bearing of the embodiment is a conical bearing 19-3-3 which is in interference fit with the horn outer liner 19-2. In the practical experiment process, when gas-liquid two-phase flows through the high-pressure metal pipe and enters the reaction kettle, the gas-liquid two-phase flows firstly into the connecting cock 25, and the connecting cock 25 and the horn liner 19-3 comprise spiral distribution flow passages with opposite directions, so that the high-speed gas-liquid mixed flow can drive the inner edge of the bearing 19-3-3, the connecting cock 25 and the horn liner 19-3 to rotate at high speed, but the horn outer liner 19-2 and the outer edge of the bearing are in a static state, the gas-liquid is fully mixed through rotation and is thrown to the inner outer edge of the reaction kettle, and the mixed fluid thrown to the inner outer edge of the reaction kettle flows along the radial direction to a screen mesh component positioned in the center of the reaction kettle, so that simulated radial flow is naturally formed. Therefore, the special design and special connection structure of the horn inlet port ensure the full mixing of gas and liquid and the simulation of radial flow at the periphery of the sieve tube.
During pressure measurement, under the rotating action of the horn inlet at the inlet end of the reaction kettle, the pressure at the inlet end of the actual reaction kettle is unstable and cannot represent the actual average pressure outside the actual screen mesh. Referring to fig. 2, in this embodiment, pressure measuring holes are respectively formed on the high-pressure metal pipes 16 outside the inlet end cover 12 and the outlet end cover 15, and a differential pressure gauge is connected between the two, for the inlet end cover, a metal pipe is added as a pressure guiding pipe 26 to the middle part of the reaction kettle to form a pressure measuring point P2, and the pressure value of the middle part outside the screen is directly measured, which can be approximately considered as the average value of the pressure outside the screen, and because the outer space of the screen is larger, the pressure is 360 ° and the inflow is all-round, so that the influence of the pressure guiding pipe on the gas-liquid flow is not worried. However, for the inside of the screen, since the inside diameter is smaller after the screen is rolled into a cylindrical drum, if a pressure guiding tube is further added, the minimum diameter of the pressure guiding tube is 3mm, and thus, the flow inside the screen is disturbed. Therefore, in order to minimize disturbance, the outlet pressure tap P1 is placed in a pipeline outside the screen, i.e., the high-pressure metal pipe 16 outside the outlet end cap 15 is perforated with pressure taps. The simulation experiment system of the embodiment designs a pressure-resistant 15MPa, the temperature control range is 0-30 ℃, and the simulation of the temperature and pressure conditions at the bottom of an actual natural gas hydrate test production well is satisfied; the inner diameter of the sapphire kettle body is 30mm, and the length is 150mm; the effective experimental length of the screen mesh is 100mm, and the diameter of the bottom plate of the screen mesh bracket is 20mm; the effective length of the gas-liquid mixing and conveying coil pipe in the closed low-temperature water bath box is 30m.
The reaction kettle body of the embodiment adopts sapphire materials, can clearly capture the position of hydrate which is preferentially generated by using a high-speed camera, and can also judge the blocking degree of the whole screen by using the rising condition of pressure difference and system pressure or a temperature jump value, thereby realizing the joint evaluation from local to whole and from naked eye quantification to data qualitative. Through the cooperation of runing rest, high-pressure metal pipe and high-pressure hose, make things convenient for reation kettle's angle modulation, make it can be convenient simulate the hydrate secondary generation and the jam condition in the screen cloth under the different well type (horizontal well, vertical well or the inclined shaft of arbitrary angle) condition. In the actual operation process, the data acquisition module acquires the pump frequency of the circulating pump, the flow rate of the circulating pump, the pressure of the circulating pump, the gas-liquid ratio, the inlet temperature of the reaction kettle, the pressure difference between the inner side and the outer side of the screen mesh and video data captured by the high-speed camera. By using the data, the rule of secondary generation of the hydrate in the screen, the degree of blockage caused by the secondary generation of the hydrate and the blockage position can be evaluated from two aspects of quantification and qualitative.
In a second embodiment, the present embodiment proposes a method for visually evaluating a blocking law of hydrate formation in a screen, and referring to fig. 8, the method includes the following steps:
(1) Determining a simulated well type, and installing an experimental flow: according to the well type simulated by the actual requirement, determining the inclination angle of the reaction kettle required by the simulation evaluation experiment of the hydrate blockage in the screen, adjusting the reaction kettle and fixing. The device is sequentially connected with a reaction kettle, a vacuum pump, a gas-liquid mixed conveying coil, a methane gas cylinder, a water supply pump, a circulating pump, a water bath refrigeration cabinet and a data acquisition module;
(2) Vacuumizing: switching on a loop flow, opening valves between the gas-liquid mixed conveying coil pipe and the reaction kettle, between the circulating pump and the reaction kettle and between the circulating pump and the gas-liquid mixed conveying coil pipe, and starting a vacuum pump to vacuumize the whole system;
(3) Pressurizing a gas-liquid mixing and conveying coil pipe: closing valves between the gas-liquid mixed conveying coil pipe and the reaction kettle and between the circulating pump and the reaction kettle, connecting a methane gas cylinder and a water supply pump, injecting quantitative methane gas and quantitative water into the coil pipe according to a set gas-water ratio, and pressurizing to a set pressure value;
(4) Reverse suction cycle: and opening valves between the gas-liquid mixing and conveying coil pipe and the reaction kettle and between the circulating pump and the reaction kettle, so that the gas-water mixture in the gas-liquid mixing and conveying coil pipe is sucked into the reaction kettle under the action of negative pressure. And then starting the circulating pump, and circulating at a fixed pump frequency to ensure that the flow pattern in the whole pipeline is basically constant. Then continuously injecting methane gas and water into the gas-liquid mixed conveying coil pipe to make up for the pressure reduction of the gas-liquid mixed conveying coil pipe caused by the back suction of the reaction kettle;
(5) Starting collection and cooling simulation: and (3) synchronously with the step (4), injecting methane gas and water into the gas-liquid mixing and conveying coil pipe in proportion, and maintaining the pressure at a preset value. When the flow pattern in the pipeline is basically constant in the process of the step (4) observed from the sapphire kettle body of the reaction kettle, the pressure drop at the two sides of the screen mesh also tends to be stable. At the moment, starting an acquisition system, continuously circulating at a fixed pump frequency, and acquiring video images of the high-speed camera, pressure differences, temperature and pressure changes along with time in real time in the circulating process; starting a water bath refrigeration cabinet and a low-temperature constant-temperature box, setting the same temperature value, slowly cooling the system, and observing a critical temperature condition value formed by starting enrichment of hydrate on the surface of the screen;
(6) Selecting a cooling mode and simulating blockage: and (3) synchronously with the step (4), injecting methane gas and water into the gas-liquid mixing and conveying coil pipe in proportion, and maintaining the pressure at a preset value. When the temperature condition reaches a critical temperature condition value that hydrate on the surface of the screen begins to be enriched and formed, two modes of constant-temperature continuous circulation and continuous slow cooling circulation are selected according to actual requirements, and the change rule of a hydrate blocking rule in a screen mesh with time under the constant temperature condition or the hydrate enrichment blocking rule in the screen mesh under the environment that the temperature is continuously reduced are observed;
(7) Adjusting a preset pressure value and a gas-liquid ratio, and performing cyclic simulation: the preset pressure value or the gas-liquid ratio condition of the system is adjusted, the steps (2) - (6) are repeated, and a three-dimensional distribution plate of the critical condition, in which the hydrate in the screen mesh is enriched and blocked to a certain extent, are obtained through multiple tests by using the temperature, the pressure and the gas-water ratio as coordinate axes respectively;
(8) Stopping simulation: when the pressure difference at both sides of the screen mesh is raised by more than 10 times of the high initial pressure difference, it is shown that the secondary generation of hydrate in the screen mesh has caused serious blockage of the screen, and serious productivity reduction is caused in an actual hydrate production well, and the experiment is stopped.
By the method, the following steps can be realized: observing a critical temperature value, a critical pressure value and a critical water-gas ratio of the occurrence of the hydrate enrichment blockage in a screen mesh of a sand control screen under a certain well type condition, and providing a risk prompt point for the formulation of a well bottom depressurization scheme of an actual natural gas hydrate exploitation well; observing the hydrate enrichment blocking degree in the screen mesh of the sand control screen under different well type conditions, and providing advice for the well type design of an actual natural gas hydrate production test well or the layout of the screen at the bottom of the well by comparing the blocking degree of the screen mesh under different well type conditions; and an intuitive screen mesh hydrate blocking risk prompting plate is formed for on-site trial production engineering decision making, and support is provided for evaluation of productivity influence rules caused by hydrate exploitation well sand control measures.
The present invention is not limited to the above-mentioned embodiments, and any equivalent embodiments which can be changed or modified by the technical content disclosed above can be applied to other fields, but any simple modification, equivalent changes and modification made to the above-mentioned embodiments according to the technical substance of the present invention without departing from the technical content of the present invention still belong to the protection scope of the technical solution of the present invention.
Claims (6)
1. The visual evaluation system for the formation blocking rule of the hydrate in the screen is characterized by comprising the following components:
the reaction kettle is arranged on the rotary support in the low-temperature constant-temperature box and comprises a sapphire kettle body, a screen assembly positioned in the kettle body, and an outlet end cover and an inlet end cover which are arranged at two ends of the kettle body, wherein the outer sides of the two end covers are connected with high-pressure metal pipes; the screen assembly comprises a screen mesh and a screen mesh support, the screen mesh is arranged on the screen mesh support to form a long cylinder shape and is wholly horizontally arranged, the screen mesh support comprises a circular screen support bottom plate, a screen support joint and 6-10 ribs positioned on the same cylindrical surface, one end of each rib is fixed on the circular screen support bottom plate, the other end of each rib is fixed on the screen support joint, and the diameter of the screen support bottom plate is equal to the diameter of a high-pressure metal pipe outside an outlet end cover;
the inner side of the reaction kettle inlet end cover is connected with a horn inlet port, the inlet port comprises a horn outer liner and a horn inner liner, the horn outer liner and the horn inner liner are connected through a sealing bearing, the outer edge of the bearing is in interference fit with the inner edge of the outer liner, a connecting cock is fixed on the inner edge of the bearing, the connecting cock is a conical steel block, the upper part of the connecting cock is welded with the upper part of the inner liner, a spiral-distributed inner runner is arranged in the connecting cock, an outlet of the inner runner is arranged on the side wall of the connecting cock, and the inlet is arranged above the connecting cock; the outer diameter of the lower edge of the horn liner is the same as the diameter of the bottom plate of the screen bracket, the high-pressure metal pipes outside the inlet end cover and the outlet end cover are respectively provided with a pressure measuring hole, a differential pressure gauge is connected between the two pressure measuring holes, and the pressure measuring holes on the inlet end cover penetrate into the middle part of the reaction kettle through the pressure guiding pipe; the horn lining is provided with flow guide channels which are spirally distributed from top to bottom, and the direction of the flow guide channels connected with the cock is opposite to that of the flow guide channels of the horn lining;
the inlet end of the gas-liquid mixing and conveying coil pipe is connected to the outlet end cover of the reaction kettle through a circulating pump, the middle part of the gas-liquid mixing and conveying coil pipe is connected with a water supply pump and a methane gas cylinder, the outlet end of the gas-liquid mixing and conveying coil pipe is connected with a vacuum pump and the inlet end cover of the reaction kettle, the gas-liquid mixing and conveying coil pipe is arranged in a closed low-temperature water bath box,
the high-speed camera is arranged in the low-temperature incubator and is opposite to the reaction kettle and used for capturing video data in the sapphire kettle;
and the data acquisition and processing module is used for acquiring and processing the pump speed data, the gas-liquid ratio, the system temperature, the system pressure and the video data of the high-speed camera.
2. The visual evaluation system for blocking law of hydrate formation in a screen according to claim 1, further comprising a water bath refrigerator for cooling the closed low-temperature water bath.
3. The visual evaluation system for the blocking law of hydrate formation in a screen according to claim 1, wherein the inner diameter of the sapphire kettle is 30mm and the length is 150mm; the length of the screen mesh is 100mm, and the diameter of the bottom plate of the screen bracket is 20mm; the effective length of the gas-liquid mixing and conveying coil pipe in the closed low-temperature water bath box is 30m.
4. The visual evaluation system for the blocking law of hydrate formation in a screen according to claim 1, wherein the outlet end of the gas-liquid mixing and conveying coil pipe is connected with a vacuum pump through a three-way switching valve.
5. A method for visually evaluating a plugging rule of hydrate formation in a screen using the visual evaluation system for plugging rule of hydrate formation in a screen according to any one of claims 1 to 4, comprising the steps of:
(1) Determining a simulated well type, and determining a reaction kettle inclination angle required by a simulation evaluation experiment of hydrate blockage in a screen according to the well type simulated by actual needs, wherein the reaction kettle, a vacuum pump, a gas-liquid mixed transportation coil, a methane gas cylinder, a water supply pump, a circulating pump, a water bath refrigeration cabinet and a data acquisition module are sequentially connected;
(2) Vacuumizing, namely vacuumizing the whole system;
(3) Pressurizing a gas-liquid mixing conveying coil pipe, injecting quantitative methane gas and quantitative water into the coil pipe according to a set gas-water ratio, and pressurizing to a set pressure value;
(4) The back suction circulation is carried out, so that a gas-water mixture in the gas-liquid mixing and conveying coil is sucked into the reaction kettle under the action of negative pressure, and then a circulating pump is started for fixed pump frequency circulation;
(5) Starting acquisition, cooling simulation, and acquiring video images of a high-speed camera, pressure difference, temperature and pressure change along with time in real time in the fixed pump frequency circulation process in synchronization with the step (4); starting a water bath refrigeration cabinet and a low-temperature constant-temperature box, setting the same temperature value, slowly cooling the system, and observing a critical temperature condition value formed by starting enrichment of hydrate on the surface of the screen;
(6) Selecting a cooling mode, blocking simulation, injecting methane gas and water into the gas-liquid mixing and conveying coil pipe according to a proportion in synchronization with the step (4), maintaining the pressure at a preset value, selecting two modes of constant temperature continuous circulation and continuous slow cooling circulation according to actual requirements when the temperature condition reaches a critical temperature condition value that hydrate on the surface of a screen mesh begins to be enriched and formed, and observing a change rule of a hydrate blocking rule in the screen under a constant temperature condition along with time or a hydrate enrichment blocking rule in the screen under a temperature continuous reduction environment;
(7) Adjusting a preset pressure value and a gas-liquid ratio, performing cyclic simulation, adjusting the preset pressure value or the gas-liquid ratio condition of a system, repeating the steps (2) to (6), and obtaining a three-dimensional distribution plate of a critical condition by secondarily generating hydrates in a screen with the temperature, the pressure and the gas-water ratio being coordinate axes and a three-dimensional distribution plate of the critical condition by enriching and blocking the hydrates in the screen to a certain extent through multiple tests;
(8) The simulation was stopped and the experiment was stopped when the pressure difference across the screen was raised by more than 10 times the high initial pressure difference.
6. The visual evaluation method for the blocking law of hydrate formation in a screen according to claim 5, wherein when the flow pattern of the fixed pump frequency circulating to the whole pipeline in the step (3) is stable, methane gas and water are continuously injected into the gas-liquid mixed conveying coil pipe, and the pressure reduction of the gas-liquid mixed conveying coil pipe caused by the back suction of the reaction kettle is compensated.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810196986.2A CN108226162B (en) | 2018-03-10 | 2018-03-10 | Visual evaluation system and visual evaluation method for hydrate generation blocking law in screen |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810196986.2A CN108226162B (en) | 2018-03-10 | 2018-03-10 | Visual evaluation system and visual evaluation method for hydrate generation blocking law in screen |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108226162A CN108226162A (en) | 2018-06-29 |
| CN108226162B true CN108226162B (en) | 2023-08-15 |
Family
ID=62659296
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810196986.2A Active CN108226162B (en) | 2018-03-10 | 2018-03-10 | Visual evaluation system and visual evaluation method for hydrate generation blocking law in screen |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108226162B (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109238641A (en) * | 2018-09-21 | 2019-01-18 | 大连理工大学 | A kind of safe on-line monitoring method of full visualization circulating pipe system flowing |
| CN109296345B (en) * | 2018-10-17 | 2023-10-31 | 中国石油天然气集团有限公司 | Seabed combustible ice gasification separation device |
| CN112484748A (en) * | 2019-09-11 | 2021-03-12 | 九江精密测试技术研究所 | Sealing structure of incubator turntable refrigeration conveying system |
| CN111022925A (en) * | 2019-11-18 | 2020-04-17 | 大连理工大学 | Visual swing kettle device and method for inhibiting pipeline hydrate blockage |
| CN111812131B (en) | 2020-07-21 | 2020-12-25 | 中国科学院地质与地球物理研究所 | Visual test system and method for secondary generation or decomposition process of hydrate |
| CN112031745B (en) * | 2020-08-06 | 2021-08-10 | 中国科学院广州能源研究所 | Device and method for observing formation characteristics of natural gas hydrate |
| CN112031761B (en) * | 2020-09-27 | 2022-03-11 | 西南石油大学 | Blockage removing device and method for simulating gas well hydrate blockage |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101279733A (en) * | 2008-01-18 | 2008-10-08 | 上海理工大学 | Visual system and method for gas hydrate cold storage/gas storage |
| CN101377478A (en) * | 2007-11-28 | 2009-03-04 | 中国石油大学(北京) | Method for measuring gas hydrate phase balance condition |
| CN101532936A (en) * | 2009-04-14 | 2009-09-16 | 中国地质大学（武汉） | Method and device for evaluating inhibiting ability of drilling fluid on formation and decomposition of hydrate |
| CN102120161A (en) * | 2010-12-28 | 2011-07-13 | 中国科学院广州能源研究所 | Testing simulation system for generation process of diffusion hydrates in precipitates and testing method thereof |
| CN103645285A (en) * | 2013-12-17 | 2014-03-19 | 中国海洋石油总公司 | Visualized natural gas hydrate simulation test device and method |
| CN105510529A (en) * | 2015-12-04 | 2016-04-20 | 中国石油大学(华东) | Oil-gas mixed transportation pipeline device and method for simulating formation, blocking and melting of hydrates |
| CN105675449A (en) * | 2016-02-01 | 2016-06-15 | 青岛海洋地质研究所 | Device and method for monitoring sand grain lateral migration rule for natural gas hydrate mining well |
| CN106194165A (en) * | 2016-08-26 | 2016-12-07 | 中国石油大学(华东) | Gas hydrates blocking monitoring device and method in the test of deep water gas well |
| CN208187991U (en) * | 2018-03-10 | 2018-12-04 | 青岛海洋地质研究所 | Hydrate generates laws for plugging Visual evaluation system in sieve |
-
2018
- 2018-03-10 CN CN201810196986.2A patent/CN108226162B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101377478A (en) * | 2007-11-28 | 2009-03-04 | 中国石油大学(北京) | Method for measuring gas hydrate phase balance condition |
| CN101279733A (en) * | 2008-01-18 | 2008-10-08 | 上海理工大学 | Visual system and method for gas hydrate cold storage/gas storage |
| CN101532936A (en) * | 2009-04-14 | 2009-09-16 | 中国地质大学（武汉） | Method and device for evaluating inhibiting ability of drilling fluid on formation and decomposition of hydrate |
| CN102120161A (en) * | 2010-12-28 | 2011-07-13 | 中国科学院广州能源研究所 | Testing simulation system for generation process of diffusion hydrates in precipitates and testing method thereof |
| CN103645285A (en) * | 2013-12-17 | 2014-03-19 | 中国海洋石油总公司 | Visualized natural gas hydrate simulation test device and method |
| CN105510529A (en) * | 2015-12-04 | 2016-04-20 | 中国石油大学(华东) | Oil-gas mixed transportation pipeline device and method for simulating formation, blocking and melting of hydrates |
| CN105675449A (en) * | 2016-02-01 | 2016-06-15 | 青岛海洋地质研究所 | Device and method for monitoring sand grain lateral migration rule for natural gas hydrate mining well |
| CN106194165A (en) * | 2016-08-26 | 2016-12-07 | 中国石油大学(华东) | Gas hydrates blocking monitoring device and method in the test of deep water gas well |
| CN208187991U (en) * | 2018-03-10 | 2018-12-04 | 青岛海洋地质研究所 | Hydrate generates laws for plugging Visual evaluation system in sieve |
Non-Patent Citations (1)
| Title |
|---|
| 机械防砂筛管挡砂介质堵塞机制及堵塞规律试验;董长银;贾碧霞;刘春苗;吴建平;王登庆;孙德旭;韩晓龙;;中国石油大学学报(自然科学版)(第05期);第82-88页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108226162A (en) | 2018-06-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108226162B (en) | Visual evaluation system and visual evaluation method for hydrate generation blocking law in screen | |
| CN107367450B (en) | Performance detection experimental device and evaluation method for expandable sieve tube | |
| CN106640061B (en) | A kind of pit shaft and formation fracture Coupled Flow imitative experimental appliance and method | |
| CN102518432B (en) | Test device capable of simulating plugging of high temperature and high pressure dropping strata | |
| CN102562040B (en) | Dynamic evaluation instrument for high-temperature and high-pressure drilling fluid loss | |
| CN108035700B (en) | Simulation system and method for sand carrying rule of shaft of marine natural gas hydrate production well | |
| CN105606634B (en) | The device of gas hydrates growth characteristics in a kind of observation blind pipe for X ray CT equipment | |
| CN101709639A (en) | Mineshaft multiphase flow device for simulating deep-water oil and gas production | |
| CN109520919B (en) | Simulation device and method for online detection of oil-water interface corrosion of multiphase mixed transportation pipeline | |
| CN110630228A (en) | Evaluation of CO2/N2Device and method for shaft sand production and prevention during hydrate exploitation by displacement method | |
| CN104777269A (en) | Supercritical CO2 injection and coalbed methane enhanced displacement simulation test method | |
| CN109209343A (en) | Coarse crack liquid-solid two-phase Radial Flow visual Simulation experimental provision and method | |
| CN108507919B (en) | Shale full-diameter core starting pressure test method under radial flow flowing mode | |
| CN104950088B (en) | Perforation hole plugging device for simulating underground condition | |
| CN113008682A (en) | True triaxial hydraulic fracturing simulation test device and method for natural gas hydrate reservoir | |
| WO2021159700A1 (en) | Full-size natural gas hydrate production well exploitation experimentation apparatus and method | |
| CN110702729B (en) | Device and method for testing heat insulation performance of vacuum heat insulation sleeve under simulated frozen soil environment | |
| CN206330957U (en) | One kind simulation High angle oil recovery well shaft analysis wax characteristic dynamic evaluation experimental device | |
| CN211201912U (en) | Device for evaluating wellbore sand production and prevention during hydrate exploitation by CO2/N2 displacement method | |
| CN108226398A (en) | A kind of simulation pipeline and hydrate generation experimental provision and method in multiple branched pipes | |
| CN209145582U (en) | Coarse crack liquid-solid two-phase Radial Flow visual Simulation experimental provision | |
| CN208187991U (en) | Hydrate generates laws for plugging Visual evaluation system in sieve | |
| CN104614152B (en) | Water injection experiment device for liquid metal reactor heat exchanger rupture accident simulation and measuring device | |
| CN112943180A (en) | Experimental system and method for simulating gas flow and parameter regulation of gas extraction system | |
| CN205252926U (en) | Can realize flow control's visual foam installation |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| CB02 | Change of applicant information |
Address after: No.62, Fuzhou South Road, Shinan District, Qingdao City, Shandong Province Applicant after: QINGDAO INSTITUTE OF MARINE GEOLOGY Applicant after: Qingdao Marine Science and Technology Center Address before: No.62, Fuzhou South Road, Shinan District, Qingdao City, Shandong Province Applicant before: QINGDAO INSTITUTE OF MARINE GEOLOGY Applicant before: QINGDAO NATIONAL LABORATORY FOR MARINE SCIENCE AND TECHNOLOGY DEVELOPMENT CENTER |
|
| CB02 | Change of applicant information | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |