CN105928836A - Method and apparatus for measuring liquid diffusion coefficient of rock stratum based on 3D printing and SPT technology - Google Patents

Abstract

The invention discloses a method and an apparatus for measuring the liquid diffusion coefficient of rock stratum based on 3D printing and an SPT technology. The measurement method comprises the following steps: making a natural crack structure-based transparent single-crack object model by using a 3D printer, and slicing the model; adding a fluorescence nanoparticle solution to obtained slices in a dropwise manner; emitting laser to make fluorescence particles shine; acquiring the motion grey image of the fluorescence particles at different times; dispersing by using a high-precision compaction algorithm to solve the motion displacement of the particles; and carrying out curve fitting according to an SPT formula to obtain the diffusion coefficient of the rock stratum. The method and the apparatus have the advantages of meeting of production of complex structure rocks, accurate obtaining of the displacement amount of the fluorescence particles, and high resolution, so the detection error of the rock stratum diffusion coefficient is further reduced.

Description

Print and the fomration fluids diffusion coefficient measuring method of SPT technology and device based on 3D

Technical field

The present invention relates to rock stratum diffusion coefficient fields of measurement, print and SPT based on 3D more particularly, to one The fomration fluids diffusion coefficient measuring method of technology and device.

Background technology

The natural fissure structure of rock mass is complicated with seepage flow dystropy, rock mass fissure seepage flow mechanism and quantitative description one It is directly ground, mining industry, geology, the difficulties of petroleum and natural gas engineering highest attention.3D printing technique Having been widely used for multiple field, SPT technology (single particle tracking) can be by particle Brownian movement Observation determines physical parameter or discloses interfacial phenomenon, is also that maximally effective laboratory facilities are studied in flowing.3D prints The application of technology and SPT technology can prepare Single Fracture physical model based on real structure and observation Particles Moving Process.

Summary of the invention

The present invention is to overcome at least one defect (not enough) described in above-mentioned prior art, first provides a kind of base Printing and the fomration fluids diffusion coefficient measuring method of SPT technology in 3D, the method can reduce detection rock stratum The error of diffusion coefficient.

The present invention also proposes a kind of based on 3D printing and the fomration fluids diffusion coefficient measurement apparatus of SPT technology.

For solving above-mentioned technical problem, technical scheme is as follows:

A kind of based on 3D printing and the fomration fluids diffusion coefficient measuring method of SPT technology, described method includes Following steps:

S1: prepare transparent Single Fracture material object hierarchical model based on natural fissure structure；

S2: the solution of nano fluorescent particle is dripped in section；

S3: launch laser luminous by fluorescent particles；

S4: gather fluorescent particles gray level image the most in the same time；

S5: utilize high accuracy compaction algorithm to carry out the discrete moving displacement solving particle；

S6: repeat to organize experiment more；

S7: utilize SPT formula to carry out curve fitting and obtain diffusion coefficient, SPT formula is:

$\stackrel{\‾}{x^2}=2D\mathrm{\Δ}t$

Wherein, D is Particle diffusion coefficients, and Δ t is observation interval,For particle position within the Δ t time Shifting amount.

In the preferred scheme of one, in step S1, the method preparing transparent Single Fracture mock-up is: right The fissure rock sample chosen carries out x-ray tomography (CT), builds Single Fracture mathematical model, uses Transparent Single Fracture mock-up prepared by 3D printer, then by model slice.

In step S4, the method i.e. single particle tracking (SPT) gathering fluorescent particles motion gray level image is: Water pump drives and flows containing fluorescent particles, and it is luminous that light excited particles launched by laser aid, utilizes micro-imaging to fill Put the particle position observed the most in the same time, select different time of exposure, collection of taking pictures according to Particles Moving speed The gray level image of fluorescent particles, obtains gray level image the most in the same time and is motion gray level image.

In step S5, the method utilizing high accuracy compaction algorithm to carry out the discrete moving displacement solving particle is: The Level-Set equation of the motion gray level image structure fluorescent particles moving interface according to fluorescent particles, right Level-Set equation utilizes Compact Finite Difference Method to carry out discrete solving after reinitializing, obtain fluorescent particles Position, utilizes position calculation moving displacement of fluorescent particles in time of exposure of fluorescent particles.

Level-Set method be the material interface moved in time regard as certain function phi (x, zero contour surface t), (x, t) so that at any time, moving interface Γ (t) is just φ (x, zero contour surface t) to i.e. constructed fuction φ. Due to t, φ at any time (x, zero contour surface t) is exactly active interface, so function phi (x t) meetsThis formula is Level Set equation.

Use Runge-Kutta method discrete at time orientation Level Set equation, use in space and compact Difference discrete.The Compact Difference Scheme of five rank precision isWherein

$\frac{3}{5}{F}_i^{+}+\frac{2}{5}{F}_{i-1}^{+}=\frac{1}{60}{\mathrm{\δ}}_x^{-}(-{\mathrm{\φ}}_{i+2}+11{\mathrm{\φ}}_{i+1}+47{\mathrm{\φ}}_i+3{\mathrm{\φ}}_{i-1})$

$\frac{3}{5}{F}_i^{-}+\frac{2}{5}{F}_{i+1}^{-}=\frac{1}{60}{\mathrm{\δ}}_x^{+}(-{\mathrm{\φ}}_{i-2}+11{\mathrm{\φ}}_{i-1}+47{\mathrm{\φ}}_i+3{\mathrm{\φ}}_{i+1})$

Wherein,WithBe respectively first derivative forward, backward difference operator,

A kind of realize above-mentioned printing and the dress of fomration fluids diffusion coefficient measuring method of SPT technology based on 3D Putting, described device includes:

Water pump driving means: for driving the fluid containing fluorescent particles to move；

Laser aid: use the incident illumination of certain wavelength to excite fluorescent particles luminous；

Microscopic imaging device: the ash of CCD depth of field collected by camera record fluorescent particles movement locus the most in the same time Degree image；

Computer: be calculated the diffusion of rock stratum according to the gray level image of fluorescent particles movement locus the most in the same time Coefficient.

Compared with prior art, technical solution of the present invention provides the benefit that: the present invention is based on 3D printing technique Transparent Single Fracture material object hierarchical model based on natural fissure structure can be prepared；Utilize single particle tracking (SPT), according to the flow acquisitions motion gray level image of fluorescent particles, and then structure fluorescent particles moving interface Level-Set equation；Utilize high accuracy compaction algorithm to carry out the discrete Level-Set of solving equation and obtain particle Moving displacement；Finally utilize SPT formula to carry out curve fitting and obtain diffusion coefficient.The present invention disclosure satisfy that multiple The preparation of miscellaneous Structure Rock, accurately obtains fluorescent particles displacement, and resolution is high, therefore can reduce spy further Survey the error of rock stratum diffusion coefficient.

The present invention prints based on 3D and the fomration fluids diffusion coefficient measurement apparatus of SPT technology includes that water pump drives Device, laser aid, microscopic imaging device and computer, simple to operate, with low cost, this device is above-mentioned The basis that method realizes, described method and system combines to complete and can obtain fluorescent particles exact position, resolution The measurement that rate diffusion coefficient error that is high and that record is little.

Accompanying drawing explanation

Fig. 1 is the flow chart of rock stratum of the present invention diffusion coefficient method.

Fig. 2 is the schematic diagram of rock stratum of the present invention diffusion coefficient device.

Detailed description of the invention

Accompanying drawing being merely cited for property explanation, it is impossible to be interpreted as the restriction to this patent；In order to this enforcement is more preferably described Example, some parts of accompanying drawing have omission, zoom in or out, do not represent the size of actual product；

To those skilled in the art, in accompanying drawing, some known features and explanation thereof may be omitted is to manage Solve.With embodiment, technical scheme is described further below in conjunction with the accompanying drawings.

Such as Fig. 1, a kind of print and the fomration fluids diffusion coefficient measuring method of SPT technology based on 3D, described Method comprises the following steps:

S1: prepare transparent Single Fracture material object hierarchical model based on natural fissure structure；

S2: the solution of nano fluorescent particle is dripped in section；

S3: launch laser luminous by fluorescent particles；

S4: gather fluorescent particles gray level image the most in the same time；

S5: utilize high accuracy compaction algorithm to carry out the discrete moving displacement solving particle；

S6: repeat to organize experiment more；

S7: utilize SPT formula to carry out curve fitting and obtain diffusion coefficient, SPT formula is:

$\stackrel{\‾}{x^2}=2D\mathrm{\Δ}t$

Wherein, D is Particle diffusion coefficients, and Δ t is observation interval,For particle position within the Δ t time Shifting amount.

In specific implementation process, in step S1, the method preparing transparent Single Fracture mock-up is: to choosing The fissure rock sample taken carries out x-ray tomography (CT), builds Single Fracture mathematical model, uses 3D Transparent Single Fracture mock-up prepared by printer, then by model slice.

In step S4, the method i.e. single particle tracking (SPT) gathering fluorescent particles motion gray level image is: Water pump drives and flows containing fluorescent particles, and it is luminous that light excited particles launched by laser aid, utilizes micro-imaging to fill Put the particle position observed the most in the same time, select different time of exposure, collection of taking pictures according to Particles Moving speed The gray level image of fluorescent particles, obtains gray level image the most in the same time and is motion gray level image.

In step S5, the method utilizing high accuracy compaction algorithm to carry out the discrete moving displacement solving particle is: The Level-Set equation of the motion gray level image structure fluorescent particles moving interface according to fluorescent particles, right Level-Set equation utilizes Compact Finite Difference Method to carry out discrete solving after reinitializing, obtain fluorescent particles Position, utilizes position calculation moving displacement of fluorescent particles in time of exposure of fluorescent particles.

Level-Set method be the material interface moved in time regard as certain function phi (x, zero contour surface t), (x, t) so that at any time, moving interface Γ (t) is just φ (x, zero contour surface t) to i.e. constructed fuction φ. Due to t, φ at any time (x, zero contour surface t) is exactly active interface, so function phi (x t) meetsThis formula is Level Set equation.

Use Runge-Kutta method discrete at time orientation Level Set equation, use in space and compact Difference discrete.The Compact Difference Scheme of five rank precision isWherein

$\frac{3}{5}{F}_i^{+}+\frac{2}{5}{F}_{i-1}^{+}=\frac{1}{60}{\mathrm{\δ}}_x^{-}(-{\mathrm{\φ}}_{i+2}+11{\mathrm{\φ}}_{i+1}+47{\mathrm{\φ}}_i+3{\mathrm{\φ}}_{i-1})$

$\frac{3}{5}{F}_i^{-}+\frac{2}{5}{F}_{i+1}^{-}=\frac{1}{60}{\mathrm{\δ}}_x^{+}(-{\mathrm{\φ}}_{i-2}+11{\mathrm{\φ}}_{i-1}+47{\mathrm{\φ}}_i+3{\mathrm{\φ}}_{i+1})$

Wherein,WithBe respectively first derivative forward, backward difference operator,

Such as Fig. 2, wherein, 1, fluorescent particles；2, water pump driving means；3, laser aid；4, micro-one-tenth As device；5, computer.

A kind of realize above-mentioned printing and the dress of fomration fluids diffusion coefficient measuring method of SPT technology based on 3D Putting, described device includes:

Water pump driving means: for driving the fluid containing fluorescent particles to move；

Laser aid: use the incident illumination of certain wavelength to excite fluorescent particles luminous；

Microscopic imaging device: the ash of CCD depth of field collected by camera record fluorescent particles movement locus the most in the same time Degree image；

Computer: be calculated the diffusion of rock stratum according to the gray level image of fluorescent particles movement locus the most in the same time Coefficient.

Obviously, the above embodiment of the present invention is only for clearly demonstrating example of the present invention, and not It it is the restriction to embodiments of the present invention.For those of ordinary skill in the field, in described above On the basis of can also make other changes in different forms.Here without also cannot be to all of enforcement Mode gives exhaustive.All any amendment, equivalent and improvement made within the spirit and principles in the present invention Deng, within should be included in the protection domain of the claims in the present invention.

Claims (5)

1. one kind prints and the fomration fluids diffusion coefficient measuring method of SPT technology based on 3D, it is characterised in that Said method comprising the steps of:

S1: prepare transparent Single Fracture material object hierarchical model based on natural fissure structure；

S2: the solution of nano fluorescent particle is dripped in section；

S3: launch laser luminous by fluorescent particles；

S4: gather fluorescent particles motion gray level image the most in the same time；

S5: utilize high accuracy compaction algorithm to carry out the discrete moving displacement solving particle；

S6: repeat to organize experiment more；

S7: utilize SPT formula to carry out curve fitting and obtain diffusion coefficient, SPT formula is:

$\stackrel{\‾}{x^2}=2D\mathrm{\Δ}t$

Wherein, D is Particle diffusion coefficients, and Δ t is observation interval,For particle position within the Δ t time Shifting amount.

Fomration fluids diffusion coefficient based on 3D printing and SPT technology the most according to claim 1 is measured Method, it is characterised in that in step S1, the method preparing transparent Single Fracture mock-up is: to choose Natural fissure rock sample carries out x-ray tomography (CT), builds Single Fracture mathematical model, uses 3D Transparent Single Fracture mock-up prepared by printer, then by model slice.

Fomration fluids diffusion coefficient based on 3D printing and SPT technology the most according to claim 1 is surveyed Metering method, it is characterised in that in step S4, gathers the reality of fluorescent particles motion gray level image the most in the same time Existing method is single particle tracking (SPT), flows particularly as follows: water pump drives containing fluorescent particles, laser It is luminous that device launches light excited particles, utilizes microscopic imaging device to observe particle position the most in the same time, according to grain Sub-movement velocity selects different time of exposure, takes pictures and gathers the gray level image of fluorescent particles, obtains the most in the same time Gray level image be motion gray level image.

Fomration fluids diffusion coefficient based on 3D printing and SPT technology the most according to claim 1 is surveyed Metering method, it is characterised in that in step S5, utilizes high accuracy compaction algorithm to carry out the discrete fortune solving particle The method of dynamic displacement is: construct fluorescent particles moving interface according to the motion gray level image of fluorescent particles Level-Set equation, utilizes Compact Finite Difference Method to carry out discrete solving after reinitializing Level-Set equation, Obtain the position of fluorescent particles, utilize position calculation motion bit of fluorescent particles in time of exposure of fluorescent particles Move.

5. one kind realizes printing and the rock stratum of SPT technology based on 3D described in any one of the claims 1 to 4 The device of liquid diffusion coefficient measuring method, it is characterised in that described device includes:

Water pump driving means: for driving the fluid containing fluorescent particles to move；

Laser aid: use the incident illumination of certain wavelength to excite fluorescent particles luminous；

Microscopic imaging device: the ash of CCD depth of field collected by camera record fluorescent particles movement locus the most in the same time Degree image；

Computer: be calculated the diffusion of rock stratum according to the gray level image of fluorescent particles movement locus the most in the same time Coefficient.