CN110361158A - The analogy method and device of hydrate reservoir silt particle removing migration in pressure reduction - Google Patents
The analogy method and device of hydrate reservoir silt particle removing migration in pressure reduction Download PDFInfo
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Abstract
The present invention discloses the analogy method and device of hydrate reservoir silt particle removing migration in a kind of pressure reduction, the simulator includes reservoir simulation module, supplying module, pressure control module, temperature control module and recycling module, reservoir simulation module peels off start-up course, including micro- visual module, purely radial stream reservoir simulation module and non-radial stream reservoir simulation module for loading unconsolidated sediment, generating hydrate reservoir and observing silt particle；This programme considers different streamline kenels, the hydrate regularity of distribution to the starting of hydrate reservoir sand grains, the influence of migration process, the hydrate reservoir under the conditions of different hydrate concentrations, different hydrate distribution patterns is prepared by reservoir, guarantee that hydrate is in undecomposed state in the experiment of subsequent Analysis of sanding mechanism, discussion, which is shaked out, critical pressure drop condition and shakes out kenel Evolution, predicts to provide technical support for practical recovery well Sanding Mechanism.
Description
Technical field
The invention belongs to ocean gas hydrate development fields, and in particular to can simulate and be hydrated under different flow field conditions
Object is depressured the visual simulation method and system of silt particle peeling in recovery process, silt particle migration Meso process.
Background technique
With China's Gas Hydrate In Sea Areas pilot production for the first time success, shaking out in Gas Hydrate In Sea Areas recovery process
And its Simulation of influence factor rapidly becomes studies in China hot spot.Current focus mainly passes through numerical simulation or reality
The means for testing simulation answer the occuring regularity of reservoir silt particle in pressure reduction.It is real due to lacking live test data of actually shaking out
Test the main means that simulation becomes exploitation of gas hydrates Analysis of sanding mechanism, Sanding Mechanism is predicted.Qingdao Haiyang geology is ground
Study carefully institute's (patent publication No.: CN106950153A；CN106353069A), Chinese Sea Petroleum Group Co., Ltd (patent disclosure
Number: CN108316913A), China Petroleum Univ.'s (patent publication No.: CN106680435A), Chinese Academy of Sciences's mechanics grind
Study carefully the units such as institute's (patent publication No.: CN104950074A) and be directed to different hydrate exploitation operating conditions respectively and proposes hydrate point
Sanding Mechanism experimental system for simulating and experimental method during solution output, the emphasis of these methods are to consider that hydrate exploitation produces
Gas produces water process and produces the rule of sand interprocedual, and silt particle in hydrate recovery process can not be described from the angle of microcosmic mechanism and is being stored up
Peeling, migration process in layer.
In fact, the mechanical property reduction of shake out process and reservoir during exploitation of gas hydrates is closely related,
The sanding mechanism of hydrate reservoir and the mechanical property of reservoir develop closely related.For this purpose, Qingdao Inst of Marine Geology's (patent
Publication number: CN107121359A) coupled relation that hydrate exploitation is shaked out with mechanical property is considered, it proposes based on three-axis force
Learn hydrate sand production rate-shearing strength combined detecting method of basic test principle.But this method is shaked out from macroscopic perspective explanation
Influence of the process to mechanical property, there is certain help to the peel off mechanism of hydrate reservoir sand grains, but still can not be from microcosmic
Scale verifies the relationship of decomposition of hydrate process and silt particle starting migration.To solve the above-mentioned problems, patent publication No.
CN109254137A attempts influence of the process to reservoir pore space of shaking out that hydrate reservoir is disclosed using X-CT technology.
These are beneficial to explore and all provides the foundation to the shake out research of process, sanding mechanism of the exploitation of hydrate, still
Mostly it is to carry out under one-dimensional condition, that is, does not account for the influence that reservoir flow field peels off reservoir silt particle, starts migration process,
Also it is difficult to realize visual simulation.
To sum up, the angle studied from gas hydrates production simulating sand, however it remains following problem:
(1) presently, there are weight-normality rule, light mechanism, reppear the feature of the behavior of sand result, light silt particle in reservoir, therefore need
Reinforce the research of silt particle removing in the earth formation, starting migration, migration kenel etc.；
(2) Container Rock Sanding mechanism is explained from micro-scale although having segmentation scheme at present and recognizing, but still nothing
Method inquires into decomposition of hydrate to the peeling of silt particle particle and its influence of migration process from visualization angle；
(3) influence of the special reservoir streamline kenel to hydrate reservoir sand migration is not accounted for, complexity is unable to satisfy and opens
Mode is adopted, as the sand grains in the special seepage region around hydraulic slotted liner technique gap peels off, starting kenel description.
Therefore, it is based on problem above, it would be highly desirable to propose that one kind can inquire into the stripping of hydrate reservoir silt particle based on visualization means
From, starting migration, migration kenel indoor simulation method and system, to fully consider decomposition of hydrate rate, decomposable process pair
The influence that silt particle peels off, starting is migrated, and consider different near wellbore formation percolation laws, to explore decomposition of hydrate, reservoir stream
Sanding Mechanism difference caused by the factors such as field provides technical support.
Summary of the invention
The present invention is to solve defect existing in the prior art, proposes hydrate reservoir silt particle removing in a kind of pressure reduction
The analogy method and system of migration, exploring the factors such as decomposition of hydrate, reservoir flow field with visualization means causes to store up hydrate
The control mechanism that layer shakes out provides technical support for the prediction of practical recovery well Sanding Mechanism.
The present invention, which is that the following technical solution is employed, to be realized:
The analogy method of hydrate reservoir silt particle removing migration in a kind of pressure reduction, comprising the following steps:
(1) the streamline model is selected:
Streamline kenel is determined according to practical gas hydrates reservoir conditions, and selects corresponding the streamline model, the stream
Line model includes purely radial flow field simulation model and non-radial flow model, wherein non-radial flow model includes purely linear flow field simulation mould
Type, linear gradient drop simulation model, power function pressure drop gradient simulation model, negative exponent pressure drop gradient simulation model；
(2) hydrate simulation reservoir preparation:
Step (1) selected the streamline model is installed to the simulation of hydrate reservoir silt particle removing migration in pressure reduction
In device, controls Temperature-pressure Conditions and inject water into simulator, gas generates hydrate；It, will be micro- based on image Segmentation Technology
The deposit cross-sectional image of visual module photograph carries out Threshold segmentation, with the regularity of distribution of quantitatively characterizing hydrate concentration；
The simulator of hydrate reservoir silt particle removing migration includes reservoir simulation module, supply mould in the pressure reduction
Block, pressure control module, temperature control module and recycling module, reservoir simulation module, supplying module, pressure control module and recycling module are respectively provided with
In temperature control module, supplying module, pressure control module and recycling module are connected with reservoir simulation module, the reservoir simulation module
Start-up course is peeled off for loading unconsolidated sediment, generating hydrate reservoir and observing decomposition of hydrate and silt particle, including micro-
Visual module, purely radial stream reservoir simulation module and non-radial stream reservoir simulation module, purely radial stream reservoir simulation module and non-
Visual window is provided in radial flow reservoir simulation module, micro- visual module is oppositely arranged with visual window；
(3) decompression flow setting and simulation:
The inlet pressure for controlling reservoir simulation module is invariable, controls to adjust the outlet pressure of reservoir simulation module, makes
The inlet pressure difference of reservoir simulation module remains constant always；In conjunction with supplying module, into reservoir simulation module injection and its
The equal gas-liquid mixture of internal temperature guarantees that charge velocity can maintain model inlet pressure to stablize；
(4) sand grains starts critical decompression simulation:
It is poor to change the step reservoir simulation module inlet pressure in (3), observes fixed hydrate concentration and hydrate point
Under the conditions of cloth, the sand grains at different location starts transport conditions, and incrementally increases mold passageway pressure difference using staged
Mode observes the critical pressure differential of the silt particle particle starting migration in different hydrate concentration regions, to establish hydrate concentration
Start the relationship between migration critical pressure drop with silt particle；
(5) hydrate reservoir shake out kenel evolution:
After step (4) observes the starting migration of silt particle particle, constant entrance pressure drop is persistently maintained, guarantees starting migration
Silt particle output and collect；Observe the Evolution in silt particle particle migration path, migrating channels in real time based on micro- visual module,
With formation sand production kenel under the constant production pressure drop of determination, certain hydrate concentration distribution occasion；
(6) control that streamline kenel shakes out to hydrate reservoir:
After the completion of above-mentioned steps (1)-(5), the streamline model is replaced, step (2)~(5) is repeated, verifies other streamline moulds
The thin sight sanding mechanism of hydrate reservoir under type qualifications.
Further, in the step (3), in decompression flow setting and simulation process, guarantee reservoir simulation module
Outlet, entrance absolute pressure value are above hydrate phase balance pressure, guarantee that the hydrate formed is in undecomposed state.
In addition the present invention also proposes a kind of simulator of hydrate reservoir silt particle removing migration in pressure reduction, including storage
Layer analog module, supplying module, pressure control module, temperature control module and recycling module, the reservoir simulation module, supplying module, control
Die block and recycling module are arranged in temperature control module, temperature needed for the temperature control module is used to maintain hydrate reservoir simulation
Degree condition, the supplying module are used to supply high pressure gas and water to reservoir simulation module, and the pressure control module is to control storage
Inlet pressure, outlet pressure and the system pressure of layer analog module, the recycling module is for recycling reservoir simulation module output
Gas-liquid solid；
The reservoir simulation module is for loading unconsolidated sediment, generating hydrate reservoir and observe decomposition of hydrate and mud
Sand peels off start-up course, including micro- visual module, purely radial stream reservoir simulation module and non-radial stream reservoir simulation module, pure
Visual window, micro- visual module and visual window are provided in radial flow reservoir simulation module and non-radial stream reservoir simulation module
It is oppositely arranged；Purely radial stream, which flows, is arranged purely radial flow field simulation model in reservoir simulation module, in non-radial stream reservoir simulation module
Purely linear flow field simulation model, linear gradient drop simulation model, power function pressure drop gradient simulation model or negative exponent pressure drop are set
Gradient simulation model.
Further, the reservoir simulation module includes epivalve shell, hypovalve shell, visual window, fluid-mixing entrance, mixes
Fluid outlet, reservoir sedimentation object filling slot, confining pressure cavity, entrance guiding slot and outlet collection slot, the setting of entrance guiding slot is closed to exist
Fluid-mixing arrival end, outlet collection slot are arranged in fluid-mixing outlet end；Epivalve shell and hypovalve shell are by fastening spiral shell
It tethers and connects, the central location of epivalve shell is arranged in visual window；There is and the visual window etc. on epivalve shell design on hypovalve shell
The groove of diameter, the filling slot setting of reservoir sedimentation object cooperate in the groove and with it, and reservoir sedimentation object fills setting inside slot
Different the streamline models, and the structure of reservoir sedimentation object filling slot matches with the streamline model structure.
Further, for non-radial stream reservoir simulation module, reservoir sedimentation object fills the streamline model being arranged in slot
It include: purely linear flow field simulation model, linear gradient Pressure Drop Model, power function pressure drop gradient model and negative exponent pressure drop gradient mould
Type, and the outlet of fluid-mixing entrance, fluid-mixing is oppositely arranged on the side of reservoir simulation module.
Further, for the reservoir simulation module of purely radial stream, purely radial stream reservoir sedimentation object filling slot is generally round
Dish type, and purely radial inflow entrance diversion trench, along the filling slot outer rim setting of purely radial stream reservoir sedimentation object, fluid-mixing outlet is located at
The central location of hypovalve shell.
Further, pressure-resistant glass is installed above the entrance guiding slot and outlet collection slot, pressure-resistant glass outer rim with it is upper
Valve shell is sealed by sliding ring, is confining pressure cavity above the pressure resistance glass, on confining pressure cavity and epivalve housing sidewall
The connection of confining pressure entrance, confining pressure cavity top passes through visual window and epivalve shell secure fit.
Further, the supplying module includes gas supply module, feed flow module and gas-liquid mixing module, supplies module and confession
Liquid module is connected with the arrival end of gas-liquid mixed module, and the outlet end of gas-liquid mixed module is connected with reservoir simulation module.
Further, the recycling module includes the first control recovery system and the second control recovery system, the first control
Recovery system is connected with the outlet of non-radial stream reservoir simulation module, the second control recovery system and purely radial stream reservoir simulation mould
The outlet of block is connected.
Further, the pressure control module includes inlet pressure control pump, first outlet pressure control pump and second outlet
Pressure control pump, first outlet pressure control pump are connected with the first control recovery system, second outlet pressure control pump and second
Recovery system is controlled to be connected.
Compared with prior art, the advantages and positive effects of the present invention are:
(1) the different streamline kenel of consideration is to the starting of hydrate reservoir sand grains, the influence of migration process, and designs corresponding
Reservoir simulation modular structure and corresponding analogy method process, result of study propose the design directly to reservoir reconstruction leading edge kenel
For support；
(2) by controlling different hydrate concentrations, different hydrate distribution patterns in reservoir preparation process, subsequent
Guarantee that hydrate is in stable state in Analysis of sanding mechanism experiment, eliminates decomposition of hydrate process to Analysis of sanding mechanism knot
The influence of fruit, to more can accurately react Container Rock Sanding kenel and its differentiation；
(3) when prepared by hydrate reservoir, using micro-image cutting techniques, it is applied to hydrate reservoir sand migration kenel
It divides, hydrate concentration distribution, realizes that visual Simulation hydrate sand grains carefully sees starting migration；
This programme fully considers decomposition of hydrate rate, peels off in decomposable process to silt, the influence of starting migration, and examines
Consider different near wellbore formation percolation laws, is mentioned to explore Sanding Mechanism difference caused by the factors such as decomposition of hydrate, reservoir flow field
For technical support.
Detailed description of the invention
Fig. 1 is that hydrate silt particle peels off and migration Meso process simulator schematic diagram in the embodiment of the present invention 1；
Fig. 2 is the schematic cross-sectional view of purely radial stream reservoir simulation module described in the embodiment of the present invention 1；
Fig. 3 is different etching structural schematic diagram inside sediment filling slot described in the embodiment of the present invention 1；
Fig. 4 is that silt particle described in the embodiment of the present invention 2 peels off and migration Meso process analogy method flow diagram；
Wherein: 1, supplying module；2, feed flow module；3, gas-liquid mixed module；4, inlet pressure control pump；5, micro- visual
Module；6-1, non-radial inflow entrance diversion trench；6-2, purely radial inflow entrance diversion trench；7-1, the filling of non-radial stream reservoir sedimentation object
Slot；7-1-1, purely linear flow field simulation model；7-1-2, linear gradient pressure drop flow field simulation model；7-1-3, power function pressure drop gradient mould
Analog model；7-1-4, negative exponent pressure drop gradient simulation model；7-2, purely radial stream reservoir sedimentation object fill slot；8-1, non-radial stream
Outlet collection slot；8-2, purely radial outflux afflux groove；9-1, non-radial stream reservoir simulation module；9-2, purely radial stream reservoir mould
Quasi- module；9-2-1, epivalve shell；9-2-2, hypovalve shell；9-2-3, fluid-mixing entrance；9-2-4, confining pressure entrance；9-2-
5, the sealing between reservoir simulation module body and confining pressure separation layer；9-2-6, visual window；9-2-7, confining pressure cavity；It is 9-2-8, resistance to
Press glass；9-2-9, fastening bolt；9-2-10, fluid-mixing outlet；10-1, the first control recovery system；10-2, the second control
Recovery system；11-1, first outlet pressure control pump；11-2, second outlet pressure control pump；12-1, the first confining pressure control pump；
12-2, the second confining pressure control pump；13, temperature control module；F1~F19, valve.
Specific embodiment
Above object and advantages of the invention are understood in order to clearer, with reference to the accompanying drawing to the specific reality of invention
The mode of applying describes in detail:
The simulator of hydrate reservoir silt particle removing migration, is opened in embodiment 1, a kind of pressure reduction with hydrate decompression
For adopting process, as shown in Figure 1, the simulator includes reservoir simulation module (9-1,9-2), supplying module (1,2,3), control
Die block (4,11-1,11-2,12-1,12-2), temperature control module 13 and recycling module (10-1,10-2), the reservoir simulation mould
Block (9-1,9-2), supplying module (1,2,3), pressure control module (4,11-1,11-2,12-1,12-2) and recycling module (10-1,
It 10-2) is arranged in temperature control module 13, the temperature control module 13 is mainly used for cooling down to simulator, maintains hydrate reservoir
Temperature condition needed for simulation；
It continues to refer to figure 1, the reservoir simulation module is for loading unconsolidated sediment, generating hydrate reservoir and observe water
It closes object decomposition and peels off start-up course with silt particle, be the nucleus module of this system, including micro- visual module 5, purely radial stream reservoir
Analog module 9-2 and non-radial stream reservoir simulation module 9-1, purely radial stream reservoir simulation module 9-2 and non-radial stream reservoir mould
It is provided with visual window on quasi- module 9-1, micro- visual module 5 is oppositely arranged with visual window；
The supplying module includes gas supply module 1, feed flow module 2 and gas-liquid mixing module 3, supplies module 1 and feed flow mould
Block 2 is connected with the arrival end of gas-liquid mixed module 3, and the outlet end of gas-liquid mixed module 3 is connected with reservoir simulation module, for
Reservoir simulation module supplies high pressure gas and water；
The recycling module is mainly used for recycling the gas-liquid solid of reservoir simulation module output, including the first control recycling system
Unite the control of 10-1 and second recovery system 10-2, and the first control recovery system 10-1 is with non-radial stream reservoir simulation module 9-1's
Outlet is connected, and the second control recovery system 10-2 is connected with the outlet of purely radial stream reservoir simulation module 9-2；
The pressure control module includes inlet pressure control pump 4, first outlet pressure control pump 11-1 and second outlet pressure
Control pump 11-2, the first confining pressure control pump 12-1 and the second confining pressure control pump 12-2, first outlet pressure control pump 11-1 and the
One control recovery system 10-1 is connected, and second outlet pressure control pump 11-2 is connected with the second control recovery system 10-2, mainly
Effect is inlet pressure, outlet pressure and the system pressure for controlling reservoir simulation module.First confining pressure control pump 12-1 and second
Confining pressure control pump 12-2 flows reservoir simulation module 9-1 and the purely radial confining pressure flowed on reservoir simulation module 9-2 with non-radial respectively
Cavity outlet connection, controls the confining pressure of reservoir simulation inside modules filling sedimentation object.
Reservoir simulation module described in the present embodiment includes that epivalve shell, hypovalve shell, visual window, fluid-mixing enter
Mouth, fluid-mixing outlet, reservoir sedimentation object filling slot, confining pressure cavity, entrance guiding slot and outlet collection slot etc.；Epivalve shell and
Hypovalve shell is to be connected by fastening bolt, and the central location of epivalve shell is arranged in visual window, and the window of visual window can cover
Cover all reservoir sedimentation object filling slot ranges；Design has the groove isometrical with the visual window on epivalve shell on hypovalve shell, stores up
Surface sediments filling slot is located in the groove, and the outer rim of reservoir sedimentation object filling slot and hypovalve housing groove cooperate, storage
The streamline model being arranged inside surface sediments filling slot is designed according to the difference for simulating streamlined state, and the streamline model is base
In the sediment filling slot of different shapes that the technologies such as 3D printing are formed, to have mature technology, it is not described here in detail, streamline mould
The physical dimension of type is consistent with filling slot inner wall, and the inner edge of the streamline model is designed according to required streamline kenel to be simulated, mainly
Including purely linear flow field simulation model 7-1-1, linear gradient pressure drop flow field simulation model 7-1-2, power function pressure drop gradient simulation model
7-1-3, negative exponent pressure drop gradient simulation model 7-1-4 etc..
Four kinds of the streamline models described above for non-radial stream reservoir simulation module 9-1 for, fluid-mixing enters
Mouth, fluid-mixing outlet are oppositely arranged on the side of reservoir simulation module, the inner edge of corresponding reservoir sedimentation object filling slot
Shape is corresponding with the outer rim of the streamline model, for purely linear flow field simulation model 7-1-1, injection end diversion channel and outflow end
It is identical to shunt slot length, filling slot inner edge profile is standard rectangular configuration, for linear gradient Pressure Drop Model 7-1-2, from
To outflow end diversion channel, the distance between model inner edge two sides boundary linearly reduces injection end diversion channel；Likewise, for power letter
Number pressure drop gradient model 7-1-3 and negative exponent pressure drop gradient model 7-1-4, it is assumed that around the pit shaft or transformation crack on transformation stratum
The flow pressure drop of surrounding meets power function form and negative exponent form, and the inner edge side boundaries of power function pressure drop gradient model are power
Function, the inner edge side boundaries of negative exponent pressure drop gradient model are exponential function.
The streamline model of above-mentioned difference streamline kenel, diversion trench are mounted on fluid-mixing arrival end, guarantee fluid uniformly into
Enter deposit section, diversion trench is connected with the fluid-mixing entrance of reservoir simulation module, and afflux groove is mounted on fluid-mixing and goes out
Mouth end, afflux groove are connected with the fluid-mixing outlet end of reservoir simulation module.
And for purely radial stream reservoir simulation module, structure is similar to non-radial stream reservoir simulation module, such as Fig. 2
It is shown, including epivalve shell 9-2-1, hypovalve shell 9-2-2, visual window 9-2-6, fluid-mixing entrance 9-2-3, fluid-mixing go out
Mouthful 9-2-10, purely radial stream reservoir sedimentation object fill slot 7-2, confining pressure cavity 9-2-7, purely radial inflow entrance diversion trench 6-2 and pure
Radial flow exports afflux groove 8-2；Epivalve shell 9-2-1 is to be connected by fastening bolt 9-2-9 with hypovalve shell 9-2-2, visually
The central location of epivalve shell 9-2-1 is arranged in window 9-2-6；On hypovalve shell 9-2-2 design have on epivalve shell 9-2-1
The isometrical groove of visual window, purely radial stream reservoir sedimentation object filling slot 7-2 are located in the groove, purely radial stream reservoir sedimentation
Object fills the outer rim of slot 7-2 and hypovalve housing groove cooperates.With non-radial stream reservoir simulation module 9-1 the difference is that:
The generally disc of sediment filling slot designed by its inside, entrance guiding slot 6-2 are arranged along disc excircle, mixing
Fluid outlet 9-2-10 is located at the central location of hypovalve shell, in this way design mainly in view of purely radial flow model with it is described pure
Linear flow simulation model, linear gradient Pressure Drop Model, power function pressure drop gradient model, negative exponent pressure drop gradient model become a mandarin
Mouth, the installation of outflux position are totally different, can not be with purely linear flow field simulation model, linear gradient Pressure Drop Model, power function pressure drop gradient
Model or the installation of negative exponent pressure drop gradient model interchange, thus it is slightly modified, devise two kinds of reservoir simulation modules.
In addition, for also installation pressure resistance above the sediment filling model, diversion trench, afflux groove of above-mentioned different streamline forms
Glass 9-2-8, pressure-resistant glass 9-2-8 outer rim are sealed with the shoulder on epivalve shell by sliding ring 9-2-5, the pressure resistance
It is confining pressure cavity 9-2-7 above glass, confining pressure cavity 9-2-7 is connect with the confining pressure entrance 9-2-4 in epivalve housing sidewall；It encloses
The pressure top cavity 9-2-7 and epivalve shell secure fit are transparent visual window 9-2-6.
Embodiment 2, when it is implemented, consider following basic principle:
(1) under the conditions of same formation seepage flow speed, the convergence degree difference of streamline may cause the microcosmic stress balance of particle
The change of condition.Therefore, under the conditions of identical rate of discharge (yield), the sand production rate of near wellbore formation is by around pit shaft or crack
The influence in flow field.Therefore, by Controlling model flow boundary, different streamline conditions may be implemented to sand grains starting migration process
Simulation；
(2) degree of consolidation of the silt particle particle at hydrate concentration differentia influence different location, hydrate is in reservoir
Uneven distribution be to shake out one of non-uniform principal element in position in control stratum.Identical flow velocity (producing pressure differential) condition
Under, the sand grains starting migration critical flow velocity at different location has differences, it can use in microscopic system observation hydrate reservoir,
Sand grains starts the sequencing of migration position and the relationship of hydrate distribution, defines hydrate concentration and starts fortune to reservoir sand grains
Move the influence of critical flow velocity；
(3) hydrate concentration distribution may be influence hydrate reservoir shake out kenel (hole liquefaction, earthworm hold, continuously
Collapse) principal element.Under the conditions of ultramicroscopic observation within sweep of the eye hydrate concentration distribution, certain flow
The microcosmic coupled relation therefore between hydrate distribution and kenel of shaking out can be obtained in sand grains migration path, migration rate.
Based on silt particle removing and fortune in the above basic test principle, with hydrate described in embodiment 1 decompression recovery process
Move Meso process visual Simulation device accordingly, the present embodiment proposes silt particle removing in a kind of hydrate decompression recovery process
With migration Meso process visual simulation method, as shown in Figure 4, comprising:
(1) select the streamline model: the well week being likely to occur according to practical exploitation of gas hydrates well flows around crack
Ejector half state selects purely linear flow field simulation model, linear gradient drop simulation model, power function pressure drop gradient simulation model, negative finger
Number pressure drop gradient simulation model or purely radial flow field simulation model, and actual deposition object is loaded in corresponding the streamline model, installation
Instrument；
(2) simulation model of different streamline kenels hydrate simulation reservoir preparation: is installed to decompression described in embodiment 1
In the process in the simulator of hydrate reservoir silt particle removing migration, controls Temperature-pressure Conditions and inject aqueous vapor life into simulator
At hydrate；Based on image Segmentation Technology, the deposit cross-sectional image of micro- visual module photograph is subjected to Threshold segmentation, it is quantitative
Characterize the regularity of distribution of hydrate concentration；
(3) be depressured flowsheeting: the inlet pressure of control reservoir simulation module is invariable, controls to adjust reservoir simulation mould
Block outlet pressure makes reservoir simulation module inlet pressure difference remain constant always；In conjunction with supplying module, to reservoir simulation module
The middle injection gas-liquid mixture equal with its internal temperature；Charge velocity, which is subject to, can maintain model inlet pressure to stablize；
It should be noted that in step (3), it is necessary to assure the hydrate formed is in undecomposed state, due to
The removing of silt particle described in the present embodiment is to explore the flow pattern of hydrate reservoir, hydrate saturation with migration process main purpose
The influence of the removing of Degree distributions silt particle and starting migration and kenel of shaking out, the machine so that hydrate reservoir for exploring meso-scale shakes out
Reason.If it is considered that hydrate is in dynamic Decomposition state simultaneously in sand grains starting migration process, the starting of verifying silt particle will be unable to
Migration is finally to be only capable of obtaining hydrate reservoir to shake out rule caused by decomposition of hydrate or caused by hydrate distribution and streamline influence
Rule, and more perfect explanation is then unable to get to the explanation of hydrate sanding mechanism.
(4) sand grains starting critical pressure drop simulation: changing the step mold passageway pressure difference in (3), observes fixed hydrate
Under saturation degree and hydrate distribution occasion, the sand grains at different location starts transport conditions, incrementally increases model using staged
The mode of inlet pressure observes the critical pressure differential of the sand grains starting migration in different hydrate concentration regions, to establish hydration
Relationship between object saturation degree and silt particle starting migration critical pressure drop；(5) hydrate reservoir shake out kenel evolution: in step (4)
After observing the starting migration of silt particle particle, constant entrance pressure drop is persistently maintained, guarantee the silt particle output of starting migration and is collected；
The Evolution in silt particle particle migration path, migrating channels is observed in real time based on micro- visual module, so that it is determined that constant production
Formation sand production kenel under pressure drop, certain hydrate concentration distribution occasion；
Especially it is emphasized that remaining that mold exit pressure absolute value is greater than in above-mentioned steps (4) simulation process
The vapor pressure of hydrate, to exclude the cementing reduction of deposit caused by decomposition of hydrate to the shadow of sand grains starting migration process
It rings.Therefore the present embodiment is to be developed by controlling the pressure difference of entrance and realizing to sand grains starting critical " pressure drop " and kenel of shaking out
Simulation.This is consistent with the actual conditions of practical exploitation of gas hydrates reservoir: practical exploitation of gas hydrates process
In, the principal element for influencing formation sand production situation is also due to the pressure difference that strata pressure and wellbore pressure are formed and acts on, not
Stratum absolute pressure value.
(6) control that streamline kenel shakes out to hydrate reservoir: after the completion of above-mentioned steps (1)-(5), streamline mould is replaced
Analog model repeats step (2)~(5), verifies the thin sight sanding mechanism of hydrate reservoir under other streamline qualifications.
In short, silt particle removes the visualization with migration process in the hydrate decompression recovery process that the present invention program is proposed
Simulator and method can observe different streamline kenels to sand grains starting, the influence of migration process, realize visual observation
The kenel of shaking out of hydrate reservoir under different hydrate concentrations and its distribution occasion, and the Evolution for kenel of shaking out；And
Effectively simulation and evaluation hydrate concentration and its distribution start the influence of migration critical flow velocity condition to silt particle, and then realize
Exploring the factors such as decomposition of hydrate, reservoir flow field with visualization means leads to the control mechanism to shake out to hydrate reservoir, is real
Recovery well Sanding Mechanism prediction in border provides technical support.
The above described is only a preferred embodiment of the present invention, being not that the invention has other forms of limitations, appoint
What those skilled in the art changed or be modified as possibly also with the technology contents of the disclosure above equivalent variations etc.
It imitates embodiment and is applied to other fields, but without departing from the technical solutions of the present invention, according to the technical essence of the invention
Any simple modification, equivalent variations and remodeling to the above embodiments, still fall within the protection scope of technical solution of the present invention.
Claims (10)
1. the analogy method of hydrate reservoir silt particle removing migration in pressure reduction, which comprises the following steps:
(1) the streamline model is selected:
Streamline kenel is determined according to practical gas hydrates reservoir conditions, and selects corresponding the streamline model, the streamline mould
Type includes purely radial flow field simulation model and non-radial flow model, wherein non-radial flow model includes purely linear flow field simulation model, line
Property gradient drop simulation model, power function pressure drop gradient simulation model, negative exponent pressure drop gradient simulation model；
(2) hydrate simulation reservoir preparation:
Step (1) selected the streamline model is installed to the simulator of hydrate reservoir silt particle removing migration in pressure reduction
In, it controls Temperature-pressure Conditions and injects water into simulator, gas generates hydrate；It, will be micro- visual based on image Segmentation Technology
The deposit cross-sectional image of module photograph carries out Threshold segmentation, with the regularity of distribution of quantitatively characterizing hydrate concentration；
In the pressure reduction hydrate reservoir silt particle removing migration simulator include reservoir simulation module, supplying module,
Pressure control module, temperature control module and recycling module, reservoir simulation module, supplying module, pressure control module and recycling module are arranged at
In temperature control module, supplying module, pressure control module and recycling module are connected with reservoir simulation module, and the reservoir simulation module is used
In load unconsolidated sediment, generate hydrate reservoir and observe decomposition of hydrate and silt particle peeling start-up course, including it is micro- can
Depending on module, purely radial stream reservoir simulation module and non-radial stream reservoir simulation module, purely radial stream reservoir simulation module and non-diameter
It is provided with visual window in stream reservoir simulation module, micro- visual module is oppositely arranged with visual window；
(3) decompression flow setting and simulation:
The inlet pressure for controlling reservoir simulation module is invariable, controls to adjust the outlet pressure of reservoir simulation module, makes reservoir
The inlet pressure difference of analog module remains constant always；In conjunction with supplying module, into reservoir simulation module injection with inside it
The equal gas-liquid mixture of temperature guarantees that charge velocity can maintain model inlet pressure to stablize；
(4) sand grains starts critical decompression simulation:
It is poor to change the step reservoir simulation module inlet pressure in (3), observes fixed hydrate concentration and hydrate is distributed item
Under part, the sand grains at different location starts transport conditions, and in such a way that staged incrementally increases mold passageway pressure difference,
The critical pressure differential of the silt particle particle starting migration in different hydrate concentration regions is observed, to establish hydrate concentration and silt particle
Relationship between starting migration critical pressure drop；
(5) hydrate reservoir shake out kenel evolution:
After step (4) observes the starting migration of silt particle particle, constant entrance pressure drop is persistently maintained, guarantees the mud of starting migration
Sand output is simultaneously collected；The Evolution in silt particle particle migration path, migrating channels is observed, in real time based on micro- visual module with true
Formation sand production kenel under fixed constant production pressure drop, certain hydrate concentration distribution occasion；
(6) control that streamline kenel shakes out to hydrate reservoir:
After the completion of above-mentioned steps (1)-(5), the streamline model is replaced, repeats step (2)~(5), verifies other the streamline models limit
The thin sight sanding mechanism of hydrate reservoir under fixed condition.
2. the analogy method of hydrate reservoir silt particle removing migration, feature exist in pressure reduction according to claim 1
In: in the step (3), in decompression flow setting and simulation process, guarantee outlet, the entrance absolute pressure of reservoir simulation module
Force value is above hydrate phase balance pressure, guarantees that the hydrate formed is in undecomposed state.
3. the simulator of hydrate reservoir silt particle removing migration in a kind of pressure reduction, it is characterised in that: including reservoir simulation
Module, supplying module, pressure control module, temperature control module and recycling module, the reservoir simulation module, supplying module, pressure control module
It is arranged in temperature control module with recycling module, temperature strip needed for the temperature control module is used to maintain hydrate reservoir simulation
Part, the supplying module are used to supply high pressure gas and water to reservoir simulation module, and the pressure control module is to control reservoir mould
Inlet pressure, outlet pressure and the system pressure of quasi- module, the recycling module are used to recycle the gas of reservoir simulation module output
Liquid solid；
The reservoir simulation module is for loading unconsolidated sediment, generating hydrate reservoir and observing decomposition of hydrate and silt particle stripping
Start-up course, including micro- visual module, purely radial stream reservoir simulation module and non-radial stream reservoir simulation module are fallen, it is purely radial
It is provided with visual window in stream reservoir simulation module and non-radial stream reservoir simulation module, micro- visual module is opposite with visual window
Setting；Purely radial flow field simulation model is set in purely radial stream stream reservoir simulation module, is arranged in non-radial stream reservoir simulation module
Purely linear flow field simulation model, linear gradient drop simulation model, power function pressure drop gradient simulation model or negative exponent pressure drop gradient
Simulation model.
4. the simulator of hydrate reservoir silt particle removing migration, feature exist in pressure reduction according to claim 3
In: the reservoir simulation module includes epivalve shell, hypovalve shell, visual window, fluid-mixing entrance, fluid-mixing outlet, storage
Surface sediments fill slot, confining pressure cavity, entrance guiding slot and outlet collection slot, and entrance guiding slot is arranged in fluid-mixing entrance
End, outlet collection slot are arranged in fluid-mixing outlet end；Epivalve shell is to be connected by fastening bolt with hypovalve shell, visual window
The central location of epivalve shell is set；Design has the groove isometrical with the visual window on epivalve shell, reservoir on hypovalve shell
The setting of sediment filling slot cooperates in the groove and with it, and reservoir sedimentation object, which fills, is arranged different streamline moulds inside slot
Type, and the structure of reservoir sedimentation object filling slot matches with the streamline model structure.
5. the simulator of hydrate reservoir silt particle removing migration, feature exist in pressure reduction according to claim 4
In: for non-radial stream reservoir simulation module, it includes: purely linear stream mould that reservoir sedimentation object, which fills the streamline model being arranged in slot,
Analog model, linear gradient Pressure Drop Model, power function pressure drop gradient model and negative exponent pressure drop gradient model, and fluid-mixing enters
Mouth, fluid-mixing outlet are oppositely arranged on the side of reservoir simulation module.
6. the simulator of hydrate reservoir silt particle removing migration, feature exist in pressure reduction according to claim 4
In: for the reservoir simulation module of purely radial stream, purely radial stream reservoir sedimentation object fills slot generally disc, and purely radial stream
For entrance guiding slot along the filling slot outer rim setting of purely radial stream reservoir sedimentation object, fluid-mixing outlet is located at the central position of hypovalve shell
It sets.
7. the simulator of hydrate reservoir silt particle removing migration, feature in pressure reduction according to claim 5 or 6
It is: pressure-resistant glass is installed above the entrance guiding slot and outlet collection slot, pressure-resistant glass outer rim and epivalve shell passes through cunning
Dynamic seal ring sealing, pressure resistance glass top is confining pressure cavity, the confining pressure entrance on confining pressure cavity and epivalve housing sidewall
Connection, confining pressure cavity top pass through visual window and epivalve shell secure fit.
8. the simulator of hydrate reservoir silt particle removing migration, feature exist in pressure reduction according to claim 3
In: the supplying module includes gas supply module, feed flow module and gas-liquid mixing module, supplies module and feed flow module and gas-liquid is mixed
The arrival end for molding block is connected, and the outlet end of gas-liquid mixed module is connected with reservoir simulation module.
9. the simulator of hydrate reservoir silt particle removing migration, feature exist in pressure reduction according to claim 3
In: the recycling module includes the first control recovery system and the second control recovery system, and first controls recovery system and non-diameter
It is connected to the outlet of stream reservoir simulation module, the second control recovery system is connected with the outlet of purely radial stream reservoir simulation module.
10. the simulator of hydrate reservoir silt particle removing migration, feature exist in pressure reduction according to claim 3
In: the pressure control module include inlet pressure control pump, first outlet pressure control pump and second outlet pressure control pump, first
Outlet pressure control pump is connected with the first control recovery system, second outlet pressure control pump and the second control recovery system phase
Even.
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