CN101892836A - Method for preparing large-scale porous percolating medium - Google Patents

Abstract

The invention discloses a method for preparing a large-scale porous percolating medium. In the preparation method, a discretized oil reservoir physical model is established on the basis of a discretized idea simulated by an oil-gas reservoir numerical value, i.e. small rock masses with different specific physical parameters are connected in certain sequence to form a large-scale percolating medium rock mass. Natural stratigraphic rock is adopted as a raw material, and the prepared large-scale percolating medium has the attribute of the natural stratigraphic rock and can more favorably express the natural physical characteristics of an oil-gas reservoir; and the large-scale percolating medium with any physical distribution, namely the oil-gas reservoir physical model can be formed by distributing a plurality of small masses with different physical parameters in certain sequence. A small rock mass connecting way provided by the invention can reduce the influence of the manual connection among the small rock masses on the physical distribution of the formed large-scale percolating medium to the negligible degree.

Description

Method for preparing large-scale porous percolating medium

Technical field

The present invention relates to a kind of novel physical experimental method of Porous Media research, be particularly related to the quantitative rerum natura distribution of a kind of discretization method for preparing large-scale porous percolating medium, it is primarily aimed at the research of oil-gas reservoir seepage flow and development process in the oil-gas field development field; Be applicable to the research field that other is relevant with the seepage flow phenomenon simultaneously, for example mud-stone flow disaster study on prevention, coal mine gas row adopt research, hydraulic engineering research etc.

Background technology

For guaranteeing that oil-gas field development obtains better effects, need study the flow event and the percolation law of oil-gas reservoir inner fluid.For this reason, people are attempting utilizing physical model that oil-gas reservoir seepage flow is carried out analog study always, promptly scaled actual oil-gas reservoir according to the principle of similitude, test in seepage flow of observation test oil-gas reservoir intuitively and the development process in a certain respect or the rule of some aspect and characteristic by mini Mod.But, do not find successful oil-gas reservoir PHYSICAL MODELING OF IN report before this as yet.

The main difficulty of oil-gas reservoir physical analogy is that physical model is difficult to satisfy the condition of similarity of flow event in the oil-gas reservoir.

The main body of oil-gas reservoir physical model is a porous percolating medium, often is called rock core or rock mass.Because actual oil-gas reservoir all is heterogeneous body, according to the principle of similitude, experimental model also must be a heterogeneous body, and promptly physical-property parameters such as the permeability of porous percolating medium, degree of porosity must present specific non-uniform Distribution according to similar requirement in the reservoir models.Simultaneously, in order to satisfy multinomial similitude condition, need the experimental model of large scale as far as possible.Therefore, the making of the porous percolating medium of the large scale of rerum natura distribution quantification just becomes the matter of utmost importance of oil-gas reservoir physical analogy.

Before this, people set up the oil-gas reservoir physical model and mainly contain two kinds of methods.The artificial rock mass of the first promptly by back-up sand, compacting, glued process, is made selected sand the percolating medium rock mass of definite shape.The control because very difficult control compacting and glued heterogeneity, physical parameters such as the permeability of artificial rock mass inside and degree of porosity are also had no way of, even can't determine at all.In addition, do not find that at present reliable method can produce the rock mass of the above yardstick of 0.8m.Two of oil-gas reservoir Method of Physical Modeling is to select the stratum rock mass of appearing for use, the monoblock rock mass that the takes off certain size percolating medium as the oil-gas reservoir physical model of promptly appearing from the rock stratum.But owing to can't test the physical parameter of the inner arbitrfary point of natural rock mass, its internal penetration rate and degree of porosity etc. distribute and are difficult to determine.Simultaneously, the yardstick of natural rock mass also is subjected to exploiting the restriction with processing conditions.Hence one can see that, and disclosed method all can't satisfy the needs of oil-gas reservoir physical analogy to the porous percolating medium of the large scale of rerum natura distribution quantification before this, causes the oil-gas reservoir physical analogy to be difficult to realize.

Summary of the invention

The technical problem to be solved in the present invention is: the method for preparing large-scale porous percolating medium that a kind of rerum natura distribution quantification is provided, it is based on discretization thought, according to percolation hydraulic theory and experimental study, set up the preparation method of the quantitative rerum natura distribution of discretization large-scale porous percolating medium.

Technical solution of the present invention is: a kind of method for preparing large-scale porous percolating medium, it is characterized in that, this preparation method is based on the discretization thought of oil-gas reservoir numerical simulation, and the little sillar that will have different specific physical parameters links the percolating medium rock mass that forms large scale in certain sequence.

Preferably, described preparation method may further comprise the steps:

S1, with oil-gas reservoir dummy model discretization: the physical parameter that will be distributed in the oil-gas reservoir dummy model is discrete, to obtain a plurality of discrete physical parameters;

S2, the little sillar of processing and preparing: aforementioned a plurality of discrete physical parameters are corresponded to a plurality of little sillars, and screening meets the natural stratum rock that the physical parameter among the step S1 requires, carry out cutting processing to obtain to have the little sillar of required specific physical parameter;

S3, aforementioned little sillar is linked in order, to form the percolating medium rock mass of large scale.

As shown in the above, the present invention proposes quantitatively the distribute novel method system of large-scale porous percolating medium of the perfect making rerum natura of a cover, its method principle, preparation method, technical key point, technical data and the method step of having set forth in conjunction with specific embodiment part as can be known, the characteristics of this preparation method are as follows:

1, this method system is a basic principle with original discretization thought, is about to the whole dummy model discretization of oil-gas reservoir, links with small scale media units (little sillar) and makes large scale percolating medium (big rock mass), sets up the discretization physical model.

2, adopt the natural stratum rock as the little sillar of raw material processing and fabricating, have the attribute of natural stratum rock, can express the natural rerum natura characteristics of oil-gas reservoir better with this large scale percolating medium of setting up.The material of natural rock should be tried one's best evenly, is evenly distributed to guarantee the inner rerum natura of single little sillar.

3, screening has the little sillar of different physical parameters in a large number, and it is linked according to certain order, forms to have the discrete physical model that any rerum natura distributes.

4, the mode of connection of little sillar.Adopt specific cementing agent that little sillar is adhered to one another, constitute large scale percolating medium rock mass.Cementing agent is symmetrically distributed with netted tree lace form on adhesive surface.

5, carry out theory and experimental study by irregular seepage flow to little sillar and tree lace grid, grasped the influence rule of parameters such as adhesive surface tree lace quantity and tree lace width, and rule is carried out complex optimum to tree lace spacing and tree lace width according to this to the percolating medium rerum natura.

6, through repetition test, determine that the length of side of the little sillar of cube is got 50mm, unidirectional tree lace quantity is got 4, tree lace width to get 3mm is optimal parameter on each face.

7, selection of binder.(1) water-fast, oil resistant; (2) adhesion strength is not less than the cementing strength of natural sillar inside self; (3) viscosity is easy to be in harmonious proportion; (4) setting time should be longer than bonding operation required time slightly.Generally can select epoxy resin as cementing agent.

8, the shape of little sillar.For fear of the beam-shaping effect of link surface to big rock mass percolation flow physical properties, little sillar should equate that at the yardstick of all directions therefore the shape of little sillar is strict cube.The mismachining tolerance of any length of side and angle all is no more than 0.5%.

9, the length of side of the little sillar of cube is taken as 50mm.It determines that principle is: on the one hand with respect to integrated physical model, little sillar yardstick should be enough little, quantity is abundant, so that the rerum natura of accurately portraying in the big rock mass distributes; Yardstick should be tried one's best greatly on the other hand, so that reduce the quantity of little sillar, reduces the workload of physical modeling.Simultaneously, should be taken into account the facility of activitiess such as little sillar cutting, transportation, bonding.The length of side of little sillar is greater than or less than 50mm, all can make troubles to activities.

Compared with prior art, the present invention has following advantage:

1, the oil-gas reservoir physical analogy must possess the porous percolating medium of the large scale of rerum natura distribution quantification, but does not find successful preparation method both at home and abroad as yet before this.The present invention has filled up technological gap of world's oil-gas field development research field.

2, the present invention has set up the notion and the technology of " discrete physical model ", and its principle comes from original discretization thought, belongs to the original innovation technology.

3, advance of the present invention shows in the following areas at least: A. has the little sillar of different physical parameters in a large number and arranges according to certain order, and the large scale percolating medium that can constitute any required rerum natura distribution is the oil-gas reservoir physical model; B. designed little sillar mode of connection makes the artificial binding between the little sillar drop to negligible degree to the influence that formed large scale percolating medium rerum natura distributes; C. adopt the natural stratum rock as raw material, the large scale percolating medium of made has the attribute of natural stratum rock, can express the natural rerum natura characteristics of oil-gas reservoir better.

4, the present invention has provided technical thought quantification, exercisable, method and step, and has passed through case verification.

5, the present invention is the principle of whole dummy model discretization, and links the method for making the large scale medium with the small scale unit, is not only applicable to the oil-gas field development research field, can also be for other research field relevant with seepage flow phenomenon use and reference.For example mud-stone flow disaster study on prevention, coal mine gas row adopt research, hydraulic engineering research etc.

Description of drawings

Serve as reasons little sillar of Figure 1A links the schematic diagram that forms large scale percolating medium rock mass.

Figure 1B is a discretization large scale percolating medium rock mass internal construction schematic diagram.

Fig. 2 is the distribution relation schematic diagram of oil-gas reservoir dummy model rerum natura distribution isopleth and grid block physical parameter value.

Fig. 3 A, Fig. 3 B are the adhesive surface of little sillar and the plane and the schematic perspective view of netted tree lace thereof.

Fig. 4 is adjacent little sillar and adhesive surface generalized section thereof.

Fig. 5 is the schematic diagram of little sillar adhesive surface tree lace grid cell.

Fig. 6 is the schematic diagram of little sillar tree lace grid Unit 1/4.

Fig. 7 is the generalized section that adhesive surface influences PARALLEL FLOW in the sillar.

The drawing reference numeral explanation:

1,2,10, little sillar 10 ', rerum natura data point 10 ", grid block

109, tree lace 19, adhesive surface 20, bond line

100, big rock mass 100 ', rerum natura distribution isopleth

The specific embodiment

The present invention proposes a kind of method for preparing large-scale porous percolating medium, and it is based on the discretization characteristics of oil-gas reservoir numerical simulation, links the percolating medium rock mass that forms large scale in certain sequence with the little sillar with different specific physical parameters.

Particularly, described preparation method can may further comprise the steps:

S1, oil-gas reservoir design (virtual) model discretization: the distribution of the physical parameter in the designed oil-gas reservoir dummy model is dispersed, to obtain a plurality of discrete physical parameters;

S2, the little sillar of processing and preparing: aforementioned a plurality of discrete physical parameters are corresponded to a plurality of little sillars, and screening meets the natural stratum rock that the physical parameter among the step S1 requires, carry out cutting processing to obtain to have the little sillar of required specific physical parameter;

S3, aforementioned little sillar is linked in order, to form the quantitative rerum natura distribution of discretization large scale percolating medium rock mass.

Following conjunction with figs. and specific embodiment are described in further detail the research and the optimizing process of method principle of the present invention, concrete steps and each influence factor.

One, method principle

The present invention is based on the discretization thought of oil-gas reservoir numerical simulation, links the percolating medium rock mass that forms large scale in certain sequence with the little sillar with different specific physical parameters.Shown in Figure 1A, Figure 1B, the physical parameter of single little sillar can be regarded as uniformly, and the rerum natura distribution in the big rock mass is heterogeneous.The physical parameter of each little sillar is in advance through measuring, so the physical parameter of non-uniform Distribution also is known in the big rock mass.

Bonding with selected glue (epoxy resin) between the little sillar, glue is coated on the adhesive surface with the web form symmetry.Carry out theory and experimental study by irregular seepage flow to little sillar and tree lace grid, grasp the influence rule of parameters such as adhesive surface tree lace quantity and tree lace width to the percolating medium rerum natura, and rule is carried out complex optimum to tree lace spacing and tree lace width according to this, eliminates the influence of adhesive surface to the percolating medium rerum natura as far as possible.

Choose little sillar and they are linked together, just can form and have that any rerum natura distributes and the percolating medium rock mass of the large scale of arbitrary shape according to suitable bonding mode with suitable physical parameter.Therefore, this method can satisfy the needs of the large-scale porous percolating medium of making rerum natura distribution quantification.

Because the physical parameter in the above-mentioned large scale percolating medium is along with little sillar changes rather than continually varying, so can be called discretization percolating medium (rock mass); The reservoir models of making of it can be called discrete oil-gas reservoir physical model, is called for short the discrete object mould.

Two, the specific embodiment of preparation method

(1) oil-gas reservoir dummy model discretization

At first, the dummy model of designed oil-gas reservoir Physical Experiment model is divided into a plurality of square grid blocks with grid line according to the difference discrete principle, can be with reference to shown in Figure 1A, Figure 1B; Then, as shown in Figure 2, utilize the rerum natura distribution isopleth 100 ' of this dummy model, discrete the physical parameter that is distributed in the dummy model to each grid block 10 " on; and make each grid block 10 in the dummy model " central point as the rerum natura data point 10 ' of the little sillar 10 in the next step, promptly get the physical parameter of the physical parameter value of its central point as this grid block, wherein, the physical parameter value of little sillar central point can be weighted interpolation calculation by isopleth 100 ' and obtain.Those skilled in the art can understand, and can adopt the aforementioned oil-gas reservoir dummy models of technical design such as existing geology modeling, similarity analysis, microcomputer modelling, because concrete modeling process is not protection main points of the present invention, therefore, repeats no more herein.

Above-mentioned each grid block 10 " corresponding little sillar 10.The shape of little sillar 10, yardstick and quantity transitivity parameter are all identical with grid block.

For fear of the beam-shaping effect of link surface to big rock mass percolation flow physical properties, preferably, little sillar equates at the yardstick of all directions, so the shape of grid block and little sillar is cube (square).

The quantity of little sillar equals the designed reservoir models volume and the ratio of single little sillar volume, and therefore little sillar quantity is decided by the yardstick of little sillar.Definite principle of little sillar yardstick is: on the one hand with respect to integrated physical model, little sillar yardstick should be enough little, quantity is abundant, so that the rerum natura of accurately portraying in the big rock mass distributes; Yardstick should be tried one's best greatly on the other hand, so that reduce the quantity of little sillar, reduces the workload of physical modeling.Simultaneously, consider the facility of activitiess such as little sillar cutting, transportation, bonding, the preferable 50mm that is taken as of the length of side of the little sillar of cube.The length of side of little sillar too or too small all can be made troubles to activities.

The physical parameter of each little sillar is exactly the physical parameter of its corresponding grid block in discrete dummy model.Reservoir rocks medium rerum natura mainly comprises permeability, degree of porosity etc.The more common span of permeability is 0.1 * 10 ^-3MD～3000 * 10 ^-3MD, the common span of degree of porosity is 15%～30%.

(2) processing and preparing of little sillar

At first screening meets the natural stratum rock that step () physical parameter requires, as the raw material of making little sillar.The material of natural rock should be tried one's best evenly, is evenly distributed with the rerum natura that guarantees little sillar.

Cutting processing natural stratum rock is made little sillar 10 then.Preferably, little sillar is shaped as strict cube, and the error of its any length of side and angle all is no more than 0.5%.

(3) mode of connection of little sillar

Adopt specific cementing agent that little sillar is adhered to one another, constitute large scale percolating medium rock mass.Specifically comprise:

At first select suitable cementing agent.Cementing agent of a great variety, common have epoxy resin, the different acrylate of modification (brothers are good), 914 glue, cloud stone glue, Loctite glue series, 502 glue series, also has refractory inorganic adhesive series; 801 serial glue; 102 serial plastic glue; Water conservancy project glue; Foundry work glue; 101 glue; 504 glue; Hot melt adhesive; Structure glue; 601,602,609 serial glue; 703,704,705,706,708 one-component silicon rubber series.

Concrete, selection of binder with the preparation principle is:

(1) water-fast, oil resistant;

(2) adhesion strength is not less than the intensity of natural sillar self;

(3) be easy to be in harmonious proportion;

(4) setting time of the glue of preparing is longer than bonding operation required time slightly.

According to the above, select epoxy resin as cementing agent.

Then, determine the coating method (shape and area) of cementing agent on link surface.The coating method of cementing agent has very important influence to the Permeability Parameters of big rock mass, and the coating of cementing agent is required:

(1) reduces influence perpendicular to adhesive surface direction seepage flow as far as possible;

(2) guide functions in slit between the little sillar of elimination;

(3) geometric shape of all directions is identical;

(4) conform to the proterties of cementing agent, easily coating.

Through development test repeatedly (seeing for details hereinafter), the distribution shape of determining cementing agent is two groups of mutually perpendicular cross hatch, and is symmetrically distributed on adhesive surface, tree lace 109 density are 1/1.25cm, the width of the tree lace 109 after the bonding is 2～5mm, preferable selection 2.5mm～3.5mm, preferred 3.0mm.Shown in Fig. 3 A, Fig. 3 B.

(4) formation---the adhesion step of little sillar of big rock mass

Concrete adhesion step and hints on operation are as follows:

(1) chooses the base of smooth, firm flat board, and on base, mark the rock mass position as big rock mass;

(2) with little sillar set by step in (one) discrete reservoir model design scheme (dummy model) examination be placed on the base, check whether the position of each little sillar and neighbouring relations thereof suitable, are numbered respectively then;

(3) remove all sillars successively from base, the cleaning base is prepared formally to bond;

(4) bonding of little sillar is undertaken by row (from left to right), row (drawing near), layer (from bottom to top) order;

(5) begin first (the 1st layer, the 1st row, the 1st row) bonding of little sillar, this sillar only with the base bonding, therefore only need on a face, be coated with tree lace; Utilize full-automatic or semi-automatic point gum machine coating tree lace, control glue flow velocity and dispensing needle head translational speed make tree lace thin and even, continuous; Little sillar steadily by being pressed on the base, is made between little sillar and the base to reach the tightst the contact, treat to remove after glue solidifies and push.

(6) second (the 1st layer, the 1st row, the 2nd row) little sillar needs simultaneously and first little sillar and base bonding, therefore must select two adjacent faces and be coated with tree lace, all adhesive surfaces are contacted simultaneously with bonded, with little sillar steadily by being pressed on the bonding position; Its glue and push main points with described in (5);

(7) the bonding process proceed to be positioned at the 1st layer, during the little sillar of the 2nd row, the 2nd row, this sillar needs to bond with little sillar far-end and base with its left side simultaneously, therefore must select three faces adjacent and be coated with tree lace with same summit, three adhesive surfaces are contacted with separately bonded simultaneously, with little sillar steadily by being pressed on the bonding position; Its glue and push main points with described in (5) and (6); All first row that do not belong to or not the first little sillar that is listed as yet, and all therewith little sillar of its bonding situation is identical.

(8) successively repeat (5)～(7), can finish the bonding of all little sillars, form complete big rock mass.In big rock mass inside, each face of each little sillar all has tree lace to distribute and is adhered to one another with other little sillar.

Three, adhesive surface is to the research and the optimization of the influence of big rock mass physical parameter

Principle of the present invention and concrete making step have more than been introduced, introduce adhesive surface influence research and optimal design in the quantitative rerum natura distribution of the discretization large scale percolating medium rock mass that utilizes the present invention to constitute below, thereby select the parameters (as the width of tree lace 109, spacing etc.) of adhesive surface among the present invention in view of the above, and then can determine the optimum value of each parameter.

Large scale percolating medium rock mass is made of little sillar 10 and adhesive surface 19, and its physical parameter is also by little sillar and adhesive surface decision.The influence that research and 19 pairs of rerum naturas of control adhesive surface distribute is the key of large scale percolating medium rerum natura distribution quantification.Adhesive surface mainly comprises to the influence of big rock mass permeability and to two aspects that influence of big rock mass degree of porosity the influence of large scale percolating medium rock mass.For studying conveniently, the length of side of establishing the little sillar of cube is a; Because mismachining tolerance and sillar material, there is the slit inevitably in little sillar adhesive surface, and the gap width of establishing between any two adjacent little sillars is b; Simultaneously, the width of establishing the tree lace 109 on the adhesive surface is 2c.As shown in Figure 4.

(1) adhesive surface is to the impact analysis of big rock mass permeability

Adhesive surface is different at different directions to the influence of rock mass permeability.Below will be respectively to being parallel to adhesive surface and studying perpendicular to the permeability of adhesive surface direction.Wherein, adhesive surface is to the influence of vertical direction permeability, mainly comprises effect and the tree lace effect of blocking to vertical direction seepage flow of connecting of sillar and bond line 20; And adhesive surface mainly comprises the parallel effect of sillar and bond line 20 and the guide functions of bond line to the influence of parallel direction permeability.

1, adhesive surface is to the influence of vertical direction permeability

The effect of connecting of sillar and bond line: it is mutually bonding with 2 to establish two little sillars 1, and its permeability is respectively K ₁And K ₂, the permeability perpendicular to adhesive surface in the adhesive surface slit is made as K _f

Consideration is flowed perpendicular to the adhesive surface direction, and little sillar 1, bond line and little sillar 2 these three parts percolating mediums form series relationship at this moment, consider symmetry, get the seepage flow zone between little sillar 1 central cross-section AA ' and the little sillar 2 central cross-section BB ', see Fig. 4.If the series connection medium is K ' at the mean permeability perpendicular to the adhesive surface direction _⊥, the pressure reduction from end face AA ' to BB ' is Δ p, and the unit interval total flow is Q ', and fluid viscosity is μ.Then can get according to Darcy's law

$Q^{\′}=a^2\·\frac{K_{\⊥}^{\′}}{\mathrm{\μ}}\·\frac{\mathrm{\Δp}}{a+b}---\left(1\right)$

The pressure reduction of establishing little sillar 1, bond line and little sillar 2 two ends again is respectively Δ p ₁, Δ p _fWith Δ p ₂, then can get equally

$Q^{\′}=a^2\·\frac{K_1}{\mathrm{\μ}}\frac{\mathrm{\Δ}{p}_1}{a/2}---\left(2\right)$

$Q^{\′}=a^2\·\frac{K_f}{\mathrm{\μ}}\frac{\mathrm{\Δ}{p}_f}{b/2}---\left(3\right)$

$Q^{\&prime;}=a^2\&CenterDot;\frac{{\mathrm{<figure-callout\; id="2"\; label="K"\; filenames="H2009102419413E00021.png,H2009102419413E00031.png"\; state="\{\{state\}\}">K</figure-callout>}}_2}{\mathrm{\&mu;}}\frac{\mathrm{\&Delta;}{p}_2}{a/2}---\left(4\right)$

Because little sillar 1, bond line and little sillar 2 are series relationship, so have

Δp＝Δp ₁+Δp _f+Δp ₂ (5)

With (1)～(4) formula substitutions (5) formula, can get through simple derivation

$\frac{1}{K_{\&perp;}^{\&prime;}}=\frac{1}{a+b}(\frac{a}{2K_1}+\frac{a}{2{\mathrm{<figure-callout\; id="2"\; label="K"\; filenames="H2009102419413E00021.png,H2009102419413E00031.png"\; state="\{\{state\}\}">K</figure-callout>}}_2}+\frac{b}{K_f})---\left(6\right)$

Because b＜＜a, and K _f＞＞K ₁, K _f＞＞K ₂So, have

$\frac{b}{K_f}<<\frac{a}{2K_1},\frac{b}{K_f}<<\frac{a}{2K_2}---\left(7\right)$

Consider (7) formula, from (6) formula, dispense b/K _fAfter, (6) formula is reduced to

$\frac{1}{K_{\&perp;}^{\&prime;}}=\frac{a}{a+b}(\frac{1}{2K_1}+\frac{1}{2K_2})$

Arrangement can get

$K_{\&perp;}^{\&prime;}=(1+\frac{b}{a})\&CenterDot;\frac{2K_1{K}_2}{K_1+K_2}---\left(8\right)$

Here it is considers the rock mass permeability perpendicular to the adhesive surface direction that adhesive surface influences.

If suppose between little sillar to link, promptly there is not the influence of adhesive surface, then by being similar to can the connect permeability K of rock mass of top derivation for binder free and seamless ideal _⊥For

$K_{\&perp;}=\frac{2K_1{K}_2}{K_1+K_2}---\left(9\right)$

Compare (8) and (9) formula as can be known, the influence of adhesive surface has increased permeability, recruitment Δ K ' _⊥For

$\mathrm{\&Delta;}{K}_{\&perp;}^{\&prime;}=\frac{b}{a}\&CenterDot;\frac{2K_1{K}_2}{K_1+{\mathrm{<figure-callout\; id="2"\; label="K"\; filenames="H2009102419413E00021.png,H2009102419413E00031.png"\; state="\{\{state\}\}">K</figure-callout>}}_2}=\frac{b}{a}\&CenterDot;K_{\&perp;}---\left(10\right)$

The increase ratio epsilon of permeability ' _{K ⊥}For

${\mathrm{\&epsiv;}}_{K\&perp;}^{\&prime;}=\frac{K_{\&perp;}^{\&prime;}-K_{\&perp;}}{K_{\&perp;}}=\frac{b}{a}---\left(11\right)$

According to the requirement of big rock mass preparation method, so b/a≤0.5% is 0≤ε ' _{K ⊥}≤ 0.5%.

Tree lace is to the effect of blocking of vertical direction seepage flow: because the tree lace grid is evenly distributed on adhesive surface, flowing of each tree lace net region all is identical.For studying conveniently, choose one of them grid arbitrarily as research object, and be that the parallel direction of initial point, two groups of tree laces is x, y axle with the grid element center point, set up rectangular coordinate system, as shown in Figure 5.Again because in same tree lace grid to flow with respect to x, y axle all be symmetrical, so optional its 1/4 (quadrant) is as survey region, as shown in Figure 6.Because all there is tree lace at little sillar two ends, therefore the shape of institute's survey region is the elongated box of the square end, gluing part and all sides of box bottom surface all can be regarded the impermeable boundary as, it is the access of seepage flow that the bottom surface, two ends does not have the part of gluing, and be isobaric border, the pressure of entrance and exit is respectively P _InAnd P _OutSuppose that the tree lace spacing is 2h, the tree lace width is 2c, note w=h-c.In addition, glue can infiltrate in sillar in the sillar bonding process, and degree of depth note is made d, average out to 1.0mm, so the thickness of tree lace is divided into three sections, middle one section in bond line, in the little sillar that all the other two sections are present in the bond line both sides.

At first set up the Mathematical Modeling of three-dimensional single-phase steady seepage:

$\frac{{\&PartialD;}^{2}P}{\&PartialD;x^2}+\frac{{\&PartialD;}^{2}P}{{\&PartialD;\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="H2009102419413E00021.png,H2009102419413E00031.png"\; state="\{\{state\}\}">y</figure-callout>}}^2}+\frac{{\&PartialD;}^{2}P}{\&PartialD;{\mathrm{<figure-callout\; id="2"\; label="z"\; filenames="H2009102419413E00021.png,H2009102419413E00031.png"\; state="\{\{state\}\}">z</figure-callout>}}^2}=0---\left(12\right)$

$\left\{\begin{array}{c}{P(x,y,z)|}_{0\&le;x<w,0\&le;y<w,z=0}=P_{\mathrm{in}}\\ {P(x,y,z)|}_{0\&le;x<w,0\&le;y<w,z=a}=P_{\mathrm{out}}\end{array}\right.---\left(13\right)$

$\left\{\begin{array}{c}{\frac{\&PartialD;P}{\&PartialD;x}|}_{0\&le;y\&le;h,0<z<a,x=0}=0,{\frac{\&PartialD;P}{\&PartialD;x}|}_{0\&le;y\&le;h,0<z<a,x=h}=0\\ {\frac{\&PartialD;P}{\&PartialD;y}|}_{0\&le;x\&le;h,0<z<a,y=0}=0,{\frac{\&PartialD;P}{\&PartialD;y}|}_{0\&le;x\&le;h,0<z<a,y=h}=0\end{array}\right.---\left(14\right)$

$\left\{\begin{array}{c}{\frac{\&PartialD;P}{\&PartialD;x}|}_{0\&le;y\&le;w,0<z<d,x=w}=0,{\frac{\&PartialD;P}{\&PartialD;x}|}_{0\&le;y\&le;w,a-d<z<a,x=w}=0\\ {\frac{\&PartialD;P}{\&PartialD;y}|}_{0\&le;x\&le;w,0<z<d,y=w}=0,{\frac{\&PartialD;P}{\&PartialD;y}|}_{0\&le;x\&le;w,a-d<z<a,y=w}=0\end{array}\right.---\left(15\right)$

$\left\{\begin{array}{c}{\frac{\&PartialD;P}{\&PartialD;z}|}_{w\&le;x\&le;h,0\&le;y\&le;h,z=d}=0,{\frac{\&PartialD;P}{\&PartialD;z}|}_{w\&le;x\&le;h,0\&le;y\&le;h,z=a-d}=0\\ {\frac{\&PartialD;P}{\&PartialD;z}|}_{0\&le;x\&le;w,w\&le;y\&le;h,z=d}=0,{\frac{\&PartialD;P}{\&PartialD;z}|}_{0\&le;x\&le;w,w\&le;y\&le;h,z=a-d}=0\end{array}\right.---\left(16\right)$

Wherein (x, y z) are the fluid field pressure distribution function to P.Above Mathematical Modeling is difficult to try to achieve analytic solutions, finds the solution so adopt numerical method to carry out difference discrete, prepares a computer program at last and finishes computational process.At first given P during calculating _In, P _Out, a, h and c value, try to achieve pressure distribution in view of the above, try to achieve seepage velocity on the z=a/2 cross section according to Darcy formula again, try to achieve the unit interval flow Q that passes little sillar at last ".

Each little sillar can be regarded an infinitesimal in the whole big rock mass as, supposes that above-mentioned little sillar is K perpendicular to the mean permeability of adhesive surface " _⊥Can get according to Darcy formula:

$Q^{\&prime;\&prime;}=K_{\&perp;}^{\&prime;\&prime;}\frac{\mathrm{A\&Delta;P}}{\mathrm{\&mu;a}}---\left(17\right)$

Wherein, A is the cross-sectional area of little sillar, Δ P=P _In-P _Out

When little sillar bottom surface did not have tree lace, the mean permeability of supposing little sillar was K _⊥, according to Darcy formula, the flow Q that the unit interval is passed little sillar is:

$Q=K_{\&perp;}\frac{\mathrm{A\&Delta;P}}{\mathrm{\&mu;a}}---\left(18\right)$

(17), (18) two formulas are divided by and are obtained:

$\frac{K_{\&perp;}^{\&prime;\&prime;}}{K_{\&perp;}}=\frac{Q^{\&prime;\&prime;}}{Q}---\left(19\right)$

Calculate Q by formula (18), obtain Q the mean permeability K of little sillar under the different tree lace width ", just can calculate ", and calculate changes in permeability rate before and after the little sillar gluing thus according to formula (19) by numerical computations:

${\mathrm{\&epsiv;}}_{K\&perp;}^{\&prime;\&prime;}=\frac{K_{\&perp;}^{\&prime;\&prime;}-K_{\&perp;}}{K_{\&perp;}}---\left(20\right)$

When the little sillar length of side is 50mm, get different tree lace numbers and tree lace width, calculate the little sillar permeability decrease ratio that adhesive surface causes, result of calculation sees Table 1.To the result of calculation observation analysis as can be known, the reduction amplitude of permeability increases with the increase of tree lace width behind the gluing, simultaneously increasing and increase with the tree lace number.

The effect of blocking of table 1 tree lace causes vertical direction changes in permeability ratio (%)

2, adhesive surface is to the influence of parallel direction permeability

The parallel effect of sillar and bond line: consider to be parallel to flowing of adhesive surface, the seepage flow zone still is taken as from little sillar 1 central cross-section AA ' to little sillar 2 central cross-section BB ' (Fig. 4).Little sillar 1, bond line and little sillar 2 these three parts percolating mediums form relation in parallel at this moment.Because tree lace is impervious, think that the barrier effect of tree lace makes that the permeability that is parallel to adhesive surface in the adhesive surface slit is 0.

If Parallel Dielectric is K ' at the mean permeability that is parallel to adhesive surface _‖Can get through simple derivation according to Darcy's law

$K_{\left|\right|}^{\&prime;}=(1-\frac{b}{a+b})\frac{K_1+{\mathrm{<figure-callout\; id="2"\; label="K"\; filenames="H2009102419413E00021.png,H2009102419413E00031.png"\; state="\{\{state\}\}">K</figure-callout>}}_2}{2}---\left(21\right)$

Here it is considers the rock mass permeability that is parallel to adhesive surface that adhesive surface influences.Derive the permeability K of sillar in parallel under the desirable binding situation easily _‖For:

$K_{\left|\right|}=\frac{K_1+{\mathrm{<figure-callout\; id="2"\; label="K"\; filenames="H2009102419413E00021.png,H2009102419413E00031.png"\; state="\{\{state\}\}">K</figure-callout>}}_2}{2}---\left(22\right)$

As seen, the influence of adhesive surface has reduced the permeability that is parallel to adhesive surface, changes in permeability value Δ K ' _‖For

$\mathrm{\&Delta;}{K}_{\left|\right|}^{\&prime;}=-\frac{b}{a+b}\frac{K_1+{\mathrm{<figure-callout\; id="2"\; label="K"\; filenames="H2009102419413E00021.png,H2009102419413E00031.png"\; state="\{\{state\}\}">K</figure-callout>}}_2}{2}---\left(23\right)$

Changes in permeability ε ' _{K ‖}For

${\mathrm{\&epsiv;}}_{K\left|\right|}^{\&prime;}=\frac{b}{a+b}\&le;0.5\%---\left(24\right)$

The guide functions of bond line: when flow direction was parallel to adhesive surface, bond line had high guide functions, and showing as the rock mass permeability increases.Because the symmetry in flow field between each bar tree lace, only the 1/4 zone research that need get between two tree laces gets final product, as shown in phantom in Figure 4; The geometric parameter and the flow tendency of this survey region are seen Fig. 7.

Above-mentioned flowing can be used as two-dimentional flowing process.For studying conveniently, be the origin of coordinates with the summit of flow region, be that x, y axle are set up rectangular coordinate system with two sidelines of cross section, as shown in Figure 7.Suppose that bond line is without hindrance flowing, promptly permeability is infinitely great, and the non-tree lace zone of then little sillar adhesive surface is isobaric border.As research object, set up the Mathematical Modeling of steady seepage with the little sillar zone among Fig. 7:

$\frac{{\&PartialD;}^{2}P}{\&PartialD;x^2}+\frac{{\&PartialD;}^{2}P}{\&PartialD;{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="H2009102419413E00021.png,H2009102419413E00031.png"\; state="\{\{state\}\}">y</figure-callout>}}^2}=0---\left(25\right)$

$\left\{\begin{array}{c}{P(x,y)|}_{x=\mathrm{0,0}\&le;y\&le;a/2}=P_{\mathrm{in}}\\ {P(x,y)|}_{0\&le;x\&le;w,y=0}=P_{\mathrm{in}}\\ {P(x,y)|}_{x=h,d\&le;y\&le;a/2}=P_{\mathrm{out}}\end{array}\right.---\left(26\right)$

$\left\{\begin{array}{c}{\frac{\&PartialD;P}{\&PartialD;x}|}_{0\&le;y\&le;d,x=w}=0\\ {\frac{\&PartialD;P}{\&PartialD;y}|}_{w\&le;x\&le;h,y=d}=0\\ {\frac{\&PartialD;P}{\&PartialD;y}|}_{0\&le;x\&le;h,y=a/2}=0\end{array}\right.---\left(27\right)$

Above Mathematical Modeling adopts numerical method to carry out difference discrete and finds the solution, and prepares a computer program at last and finishes computational process.At first try to achieve the seepage field pressure distribution during calculating, try to achieve the seepage velocity of the port of export again according to Darcy formula, and obtain passing the unit interval flow Q of little sillar thus " _‖

Suppose that the mean permeability that above-mentioned little sillar is parallel to adhesive surface is K " _‖Can get according to Darcy formula:

$Q_{\left|\right|}^{\&prime;\&prime;}=K_{\left|\right|}^{\&prime;\&prime;}\frac{\mathrm{A\&Delta;P}}{\mathrm{\&mu;a}}---\left(28\right)$

Wherein, A is the cross-sectional area of little sillar, Δ P=P _In-P _Out

When supposing not have tree lace around little sillar, the mean permeability of little sillar is K _‖, according to Darcy formula, the flow Q that the unit interval is passed little sillar is:

$Q_{\left|\right|}=K_{\left|\right|}\frac{\mathrm{A\&Delta;P}}{\mathrm{\&mu;a}}---\left(29\right)$

(28), (29) two formulas are divided by and are obtained:

$\frac{K_{\left|\right|}^{\&prime;\&prime;}}{K_{\left|\right|}}=\frac{Q_{\left|\right|}^{\&prime;\&prime;}}{Q}---\left(30\right)$

Obtain Q by numerical computations " _‖, calculate Q by formula (29), just can calculate the mean permeability K of little sillar under the different tree lace width according to formula (30) " _‖, and calculate little sillar gluing front and back thus because the changes in permeability rate that the bond line guide functions causes:

${\mathrm{\&epsiv;}}_{K\left|\right|}^{\&prime;\&prime;}=\frac{K_{\left|\right|}^{\&prime;\&prime;}-K_{\left|\right|}}{K_{\left|\right|}}---\left(31\right)$

Consider that adhesive surface is made up of bond line and tree lace, and the tree lace of parallel direction has occupied the part area but do not had guide functions, so the permeability variation value that obtains of aforementioned calculation also should multiply by the ratio of bond line total length and the little sillar length of side on the adhesive surface.

To the situation that the little sillar length of side is 50mm, get different tree lace numbers and tree lace width, calculate the little sillar permeability increase ratio that adhesive surface causes, result of calculation sees Table 2.Through observation analysis as can be known, the increasing degree of permeability increases with the tree lace width and reduces behind the gluing, increases and reduces rapidly with the tree lace number.

Table 2 tree lace guide functions causes parallel direction changes in permeability ratio (%)

3, adhesive surface is to the combined influence analysis of permeability

Result of study according to aforementioned the 1st and the 2nd can obtain as drawing a conclusion:

(1) adhesive surface reduces the vertical direction permeability, and the parallel direction permeability is increased; The adhesive surface tree lace increases, broadening, and the vertical direction permeability reduces amplitude and increases, and parallel direction permeability increasing degree reduces; Parallel direction permeability increasing degree changes obviously with glue number of lines (tree lace spacing), becomes non-linear contravariant relation with the glue number of lines.

(2) because six faces of little sillar all have the tree lace grid, the permeability of any direction all can be subjected to the influence of adhesive surface in vertical and parallel direction, the i.e. effect that is increased simultaneously and reduce simultaneously; So the overall changing value of bonding back sillar permeability is always less than that bigger changing value in vertical and the parallel direction changing value.

(3) the parallel direction changes in permeability concentrates near the less banded zone of adhesive surface, and the vertical direction changes in permeability is distributed in the seepage flow zone of passing whole adhesive surface, and the former more is easy to generate the heterogeneous body effect.

(4) when tree lace quantity be 3 and tree lace width greater than 3mm, or tree lace quantity is when being not less than 4, parallel direction permeability value added is less than 10%.

(5) as long as satisfy one of following condition, then the vertical direction permeability reduces value all less than 10%:＜1〉glue number of lines is not more than 3;＜2〉the glue number of lines is 4, and the tree lace width is not more than 3.5mm;＜3〉the glue number of lines is 5, and the tree lace width is not more than 3.0mm;＜4〉the glue number of lines is 6, and the tree lace width is not more than 2.5mm.

(6) series and parallel between sillar and the adhesive surface all is no more than 0.5% to the influence of permeability, and is respectively and reduces and increase, and cuts down mutually, therefore can ignore.

4, adhesive surface tree lace parametric optimization

The optimum principle of adhesive surface tree lace quantity and tree lace width:

(1) changing value of parallel direction, vertical direction and overall penetration rate is minimum as far as possible.

(2) parallel direction and vertical direction changes in permeability value should equate as far as possible; In the time of can't equating fully, vertical direction changes in permeability value should be greater than parallel direction permeability variation value.

(3) has the technological operation feasibility.Under the state-of-the-art, the tree lace width need could guarantee more than 3.0mm that tree lace has uniformity and continuity preferably.

According to above principle, the optimal parameter of selected tree lace grid: tree lace quantity is 4, and the tree lace width is 3mm.

Under above-mentioned tree lace parameter, adhesive surface is-2.87% to the general impacts of permeability, belongs to the seepage flow experiment and calculates range of allowable error.

(2) adhesive surface is to the influence of big rock mass degree of porosity

If the degree of porosity of little sillar is φ _m, the degree of porosity of adhesive surface is φ _f

Little sillar volume is: V _m=a ³Little sillar adds that the cumulative volume behind its adhesive surface on every side is:

V＝(a+b) ³≈a ³+3a ²b。

Adhesive surface volume V _fEqual cumulative volume and deduct little sillar volume, promptly

V _f＝V-V _m≈3a ²b

By above data and consider b＜＜a, can get the average pore φ in the cumulative volume:

$\mathrm{\&phi;}=\frac{V_m\&CenterDot;{\mathrm{\&phi;}}_m+V_f\&CenterDot;{\mathrm{\&phi;}}_f}{V}={\mathrm{\&phi;}}_m+\frac{3b}{a+3b}({\mathrm{\&phi;}}_f-{\mathrm{\&phi;}}_m)---\left(32\right)$

According to aforementioned research and parametric optimization result, get a=50mm, b=0.5% * a can get φ _f=0.58.φ wherein _fFor removing the voidage beyond the tree lace and the ratio of whole bond line volume in the bond line.Substitution (32) formula gets

$\mathrm{\&phi;}=\frac{V_m\&CenterDot;{\mathrm{\&phi;}}_m+V_f\&CenterDot;{\mathrm{\&phi;}}_f}{V}=0.00857+0.9852{\mathrm{\&phi;}}_m---\left(33\right)$

Suppose φ again _m=0.2, substitution (33) formula gets

φ＝0.2056＝1.028φ _m

Be that average pore φ is than little sillar degree of porosity φ _mValue added be 0.0056, the increase ratio is 2.8%.

In sum, it is very little that the degree of porosity in the big rock mass is influenced by adhesive surface, can ignore.Big rock mass internal porosity distributes only relevant with the degree of porosity of the little sillar of forming it.

Though the present invention discloses with specific embodiment; but it is not in order to limit the present invention; any those skilled in the art; the displacement of the equivalent assemblies of under the prerequisite that does not break away from design of the present invention and scope, having done; or, all should still belong to the category that this patent is contained according to equivalent variations and modification that 7 scopes of patent protection of the present invention are done.

Claims (26)

1. method for preparing large-scale porous percolating medium, it is characterized in that, this preparation method is based on the discretization thought of oil-gas reservoir numerical simulation, set up discretization oil-gas reservoir physical model, promptly link the percolating medium rock mass that forms large scale in certain sequence with little sillar with different specific physical parameters.

2. method for preparing large-scale porous percolating medium as claimed in claim 1 is characterized in that, described preparation method may further comprise the steps:

S1, with oil-gas reservoir dummy model discretization: the physical parameter that will be distributed in the oil-gas reservoir dummy model is discrete, to obtain a plurality of discrete physical parameters;

S2, the little sillar of processing and preparing: aforementioned a plurality of discrete physical parameters are corresponded to a plurality of little sillars, and screening meets the natural stratum rock that the physical parameter among the step S1 requires, carry out cutting processing to obtain to have the little sillar of required specific physical parameter;

S3, aforementioned little sillar is linked in order, to form the quantitative rerum natura distribution of discretization large scale percolating medium rock mass.

3. method for preparing large-scale porous percolating medium as claimed in claim 2, it is characterized in that, comprise among the described step S1: according to the difference discrete principle, be divided into a plurality of square grid blocks with grid line, discrete to each grid block the physical parameter that is distributed in the oil-gas reservoir dummy model then.

4. method for preparing large-scale porous percolating medium as claimed in claim 3 is characterized in that, described step S1 is the physical parameter value that makes each grid block in the oil-gas reservoir dummy model get its central point, as the physical parameter of this grid block.

5. method for preparing large-scale porous percolating medium as claimed in claim 4 is characterized in that, among the described step S2, is with the corresponding little sillar of above-mentioned each grid block.

6. method for preparing large-scale porous percolating medium as claimed in claim 5 is characterized in that, the shape of described each little sillar, yardstick and quantity transitivity parameter are all identical with corresponding grid block.

7. method for preparing large-scale porous percolating medium as claimed in claim 6 is characterized in that the shape of described grid block and little sillar is cube, to avoid the beam-shaping effect of link surface to big rock mass percolation flow physical properties.

8. method for preparing large-scale porous percolating medium as claimed in claim 3, it is characterized in that, in step S1 during to oil-gas reservoir dummy model discretization, be the quantity of determining grid block in conjunction with the suitable yardstick of little sillar, wherein, definite principle of little sillar yardstick is: on the one hand with respect to integrated physical model, little sillar yardstick should be enough little, quantity is abundant, so that the rerum natura of accurately portraying in the big rock mass distributes; Yardstick should be tried one's best greatly on the other hand, so that reduce the quantity of little sillar, reduces the workload of physical modeling.

9. method for preparing large-scale porous percolating medium as claimed in claim 7 is characterized in that, the length of side of the little sillar of cube is 50mm.

10. method for preparing large-scale porous percolating medium as claimed in claim 1 is characterized in that, during cutting processing, the error of any length of side of described little sillar and angle all is equal to or less than 0.5%.

11. method for preparing large-scale porous percolating medium as claimed in claim 2 is characterized in that, among the described step S3, is to adopt cementing agent that little sillar is together connected to each other.

12. method for preparing large-scale porous percolating medium as claimed in claim 11 is characterized in that, described selection of binder and preparation condition are:

(1) water-fast, oil resistant;

(2) adhesion strength is not less than the intensity of natural sillar self;

(3) be easy to be in harmonious proportion;

(4) setting time of the glue of preparing is longer than bonding operation required time slightly.

13. method for preparing large-scale porous percolating medium as claimed in claim 12 is characterized in that, described cementing agent comprises epoxy resin.

14. method for preparing large-scale porous percolating medium as claimed in claim 11 is characterized in that, the coating of cementing agent is required:

(1) reduces influence perpendicular to adhesive surface direction seepage flow as far as possible;

(2) guide functions in slit between the little sillar of elimination;

(3) geometric shape of all directions is identical;

(4) conform to the proterties of cementing agent, easily coating.

15. method for preparing large-scale porous percolating medium as claimed in claim 14 is characterized in that, the distribution shape of described cementing agent is two groups of mutually perpendicular cross hatch, and is symmetrically distributed on adhesive surface.

16. method for preparing large-scale porous percolating medium as claimed in claim 15 is characterized in that, the length of side of the little sillar of cube is 50mm, and on its each face, unidirectional tree lace quantity is 4 in the tree lace grid, and the tree lace width is 3mm.

17. method for preparing large-scale porous percolating medium as claimed in claim 11 is characterized in that, in big rock mass inside, each face of each little sillar all has tree lace to distribute and is adhered to one another with other little sillar.

18. method for preparing large-scale porous percolating medium as claimed in claim 17 is characterized in that, described step S3 comprises:

(S31) choose the base of smooth, firm flat board, and on base, mark the rock mass position as big rock mass;

(S32) with little sillar set by step the discrete oil-gas reservoir dummy model design scheme examination among the S1 be placed on the base, check whether the position of each little sillar and neighbouring relations thereof suitable, are numbered respectively then;

(S33) remove all sillars successively from base, the cleaning base is prepared formally to bond;

(S34) bonding of little sillar is undertaken by the order of row from left to right, the row that draw near and layer from bottom to top;

(S35) bonding is positioned at the 1st layer of the 1st first little sillar that is listed as the 1st row, utilizes full-automatic or semi-automatic point gum machine coating tree lace, and control glue flow velocity and dispensing needle head translational speed make tree lace carefully and evenly, continuously; Little sillar steadily by being pressed on the base, is made between little sillar and the base to reach the tightst the contact, treat to remove after glue solidifies and push;

(S36) bonding is positioned at the 1st layer of the 1st second little sillar that is listed as the 2nd row, described second little sillar needs to bond with first little sillar and base simultaneously, therefore selected two adjacent faces also are coated with tree lace, all adhesive surfaces are contacted simultaneously with bonded, with little sillar steadily by being pressed on the bonding position; Its glue and push main points with described in (S35);

(S37) the bonding process proceed to be positioned at the 1st layer, during the little sillar of the 2nd row, the 2nd row, this sillar needs to bond with little sillar far-end and base with its left side simultaneously, therefore selected three faces adjacent with same summit also are coated with tree lace, three adhesive surfaces are contacted with separately bonded simultaneously, with little sillar steadily by being pressed on the bonding position; Its glue and push main points with (S35) and (S36) described in; All first row that do not belong to or not the first little sillar that is listed as yet, and all therewith little sillar of its bonding situation is identical;

(S38) successively repeat (S35)～(S37), can finish the bonding of all little sillars, form complete big rock mass.

19. method for preparing large-scale porous percolating medium as claimed in claim 15 is characterized in that, this method also comprises according to following condition determines adhesive surface tree lace quantity and tree lace width:

(1) changing value of parallel direction, vertical direction and overall penetration rate is minimum as far as possible;

(2) parallel direction and vertical direction changes in permeability value should equate as far as possible; In the time of can't equating fully, vertical direction changes in permeability value should be greater than parallel direction permeability variation value;

(3) have the technological operation feasibility, under the state-of-the-art, the tree lace width need could guarantee more than 3.0mm that tree lace has uniformity and continuity preferably.

20. method for preparing large-scale porous percolating medium as claimed in claim 15 is characterized in that, this method also comprises the influence that the quantification adhesive surface distributes to big rock mass rerum natura, and optimizes the parameters of adhesive surface in view of the above.

21. method for preparing large-scale porous percolating medium as claimed in claim 20 is characterized in that, described quantification comprises:

Q1. quantize the influence of adhesive surface to big rock mass permeability; And

Q2. quantize the influence of adhesive surface to big rock mass degree of porosity.

22. method for preparing large-scale porous percolating medium as claimed in claim 21 is characterized in that, described quantization step Q1 comprises:

Q11. the permeability influence perpendicular to the adhesive surface direction quantizes to big rock mass to adhesive surface; And

Q12. adhesive surface is quantized the permeability influence that big rock mass is parallel to the adhesive surface direction.

23. method for preparing large-scale porous percolating medium as claimed in claim 22 is characterized in that, described step Q11 comprises:

Q111. calculate the effect of connecting of sillar and bond line:

If the first little sillar is mutually bonding with the second little sillar, the length of side of the little sillar of cube is a, and its permeability is respectively K ₁And K ₂, the gap width of adhesive surface is b between two little sillars, the permeability perpendicular to adhesive surface in the adhesive surface slit is made as K _f

Consideration is flowed perpendicular to the adhesive surface direction, this three parts percolating medium of the first little sillar, bond line and the second little sillar forms series relationship at this moment, consider symmetry, get the seepage flow zone between the first little sillar central cross-section AA ' and the second little sillar central cross-section BB ', establishing the series connection medium is K ' at the mean permeability perpendicular to the adhesive surface direction _⊥, the pressure reduction from the first little sillar central cross-section AA ' to the second little sillar central cross-section BB ' is Δ p, and the unit interval total flow is Q ', and fluid viscosity is μ, then can get according to Darcy's law

$Q^{\&prime;}=a^2\&CenterDot;\frac{K_{\&perp;}^{\&prime;}}{\mathrm{\&mu;}}\&CenterDot;\frac{\mathrm{\&Delta;p}}{a+b}---\left(1\right)$

The pressure reduction of establishing the first little sillar, bond line and the second little sillar two ends again is respectively Δ p ₁, Δ p _fWith Δ p ₂, then can get equally

$Q^{\&prime;}=a^2\&CenterDot;\frac{K_1}{\mathrm{\&mu;}}\frac{\mathrm{\&Delta;}{p}_1}{a/2}---\left(2\right)$

$Q^{\&prime;}=a^2\&CenterDot;\frac{K_f}{\mathrm{\&mu;}}\frac{\mathrm{\&Delta;}{p}_f}{b}---\left(3\right)$

$Q^{\&prime;}=a^2\&CenterDot;\frac{K_2}{\mathrm{\&mu;}}\frac{\mathrm{\&Delta;}{p}_2}{a/2}---\left(4\right)$

Because the first little sillar, bond line and the second little sillar are series relationship, so have

Δp＝Δp ₁+Δp _f+Δp ₂ (5)

With (1)～(4) formula substitutions (5) formula, can get through simple derivation

$\frac{1}{K_{\&perp;}^{\&prime;}}=\frac{1}{a+b}(\frac{a}{2K_1}+\frac{a}{2K_2}+\frac{b}{K_f})---\left(6\right)$

Because b＜＜a, and the slit intrinsic permeability is much larger than sillar intrinsic permeability, i.e. K _f＞＞K ₁, K _f＞＞K ₂So, have

$\frac{b}{K_f}<<\frac{a}{2K_1},\frac{b}{K_f}<<\frac{a}{2K_2}---\left(7\right)$

Consider (7) formula, from (6) formula, dispense b/K _fAfter, (6) formula is reduced to

$\frac{1}{K_{\&perp;}^{\&prime;}}=\frac{a}{a+b}(\frac{1}{2K_1}+\frac{1}{2K_2})$

Arrangement can be considered the rock mass permeability perpendicular to the adhesive surface direction of adhesive surface influence

$K_{\&perp;}^{\&prime;}=(1+\frac{b}{a})\&CenterDot;\frac{2K_1{K}_2}{K_1+K_2}---\left(8\right)$

If suppose between little sillar to link, promptly there is not the influence of adhesive surface, then by being similar to can the connect permeability K of rock mass of top derivation for binder free and seamless ideal _⊥For

$K_{\&perp;}=\frac{2K_1{K}_2}{K_1+K_2}---\left(9\right)$

Compare (8) and (9) formula as can be known, the influence of adhesive surface increases permeability, and recruitment Δ K ' _⊥For

$\mathrm{\&Delta;}{K}_{\&perp;}^{\&prime;}=\frac{b}{a}\&CenterDot;\frac{2K_1{K}_2}{K_1+K_2}=\frac{b}{a}\&CenterDot;K_{\&perp;}---\left(10\right)$

The increase ratio epsilon of permeability ' _{K ⊥}For

${\mathrm{\&epsiv;}}_{K\&perp;}^{\&prime;}=\frac{K_{\&perp;}^{\&prime;}-K_{\&perp;}}{K_{\&perp;}}=\frac{b}{a}---\left(11\right)$

Q112. calculate the influence of blocking of tree lace to vertical direction seepage flow:

Choose one of them tree lace grid arbitrarily as research object, and be that the parallel direction of initial point, two groups of tree laces is x, y axle with the grid element center point, set up rectangular coordinate system, and optional its 1/4 as survey region, the shape of institute's survey region is the elongated box of the square end, and gluing part and all sides of box bottom surface all can be regarded the impermeable boundary as, and it is the access of seepage flow that the bottom surface, two ends does not have the part of gluing, and be isobaric border, the pressure of entrance and exit is respectively P _InAnd P _OutIf the tree lace spacing is 2h, the tree lace width is 2c, note w=h-c; Glue can infiltrate in sillar in the sillar bonding process, and degree of depth note is made d, experiment measuring under multiple situation, d average out to 1.0mm, so the thickness of tree lace is divided into three sections, middle one section in bond line, in the little sillar that all the other two sections are present in the bond line both sides;

At first set up the Mathematical Modeling of three-dimensional single-phase steady seepage:

$\frac{{\&PartialD;}^{2}P}{\&PartialD;x^2}+\frac{{\&PartialD;}^{2}P}{\&PartialD;y^2}+\frac{{\&PartialD;}^{2}P}{\&PartialD;z^2}=0---\left(12\right)$

$\left\{\begin{array}{c}P(x,y,z){|}_{0\&le;x<w,0\&le;y<w,z=0}=P_{\mathrm{in}}\\ P(x,y,z){|}_{0\&le;x<w,0\&le;y<w,z=a}=P_{\mathrm{out}}\end{array}\right.---\left(13\right)$

$\left\{\begin{array}{cc}\frac{\&PartialD;P}{\&PartialD;x}{|}_{0\&le;y\&le;h,0<z<a,x=0}=0,& \frac{\&PartialD;P}{\&PartialD;x}{|}_{0\&le;y\&le;h,0<z<a,x=h}=0\\ \frac{\&PartialD;P}{\&PartialD;y}{|}_{0\&le;x\&le;h,0<z<a,y=0}=0,& \frac{\&PartialD;P}{\&PartialD;y}{|}_{0\&le;x\&le;h,0<z<a,y=h}=0\end{array}\right.---\left(14\right)$

$\left\{\begin{array}{cc}\frac{\&PartialD;P}{\&PartialD;x}{|}_{0\&le;y\&le;w,0<z<d,x=w}=0,& \frac{\&PartialD;P}{\&PartialD;x}{|}_{0\&le;y\&le;w,a-d<z<a,x=w}=0\\ \frac{\&PartialD;P}{\&PartialD;y}{|}_{0\&le;x\&le;w,0<z<d,y=w}=0,& \frac{\&PartialD;P}{\&PartialD;y}{|}_{0\&le;x\&le;w,a-d<z<a,y=w}=0\end{array}\right.---\left(15\right)$

$\left\{\begin{array}{cc}\frac{\&PartialD;P}{\&PartialD;z}{|}_{w\&le;x\&le;h,0\&le;y\&le;h,z=d}=0,& \frac{\&PartialD;P}{\&PartialD;z}{|}_{w\&le;x\&le;h,0\&le;y\&le;h,z=a-d}=0\\ \frac{\&PartialD;P}{\&PartialD;z}{|}_{0\&le;x\&le;w,w\&le;y\&le;h,z=d}=0,& \frac{\&PartialD;P}{\&PartialD;z}{|}_{0\&le;x\&le;w,w\&le;y\&le;h,z=a-d}=0\end{array}\right.---\left(16\right)$

Wherein (x, y z) are the fluid field pressure distribution function to P, and above Mathematical Modeling adopts numerical method to carry out difference discrete and finds the solution, and utilize the computer program of establishment to finish computational process at last: at first given P during calculating _In, P _Out, a, h, d and c value, try to achieve pressure distribution in view of the above, try to achieve seepage velocity on the z=a/2 cross section according to Darcy formula again, try to achieve the unit interval flow Q that passes little sillar at last ";

Each little sillar is regarded an infinitesimal in the whole big rock mass as, and establishing above-mentioned little sillar is K perpendicular to the mean permeability of adhesive surface " _⊥, can get according to Darcy formula:

$Q^{\&prime;\&prime;}=K_{\&perp;}^{\&prime;\&prime;}\frac{\mathrm{A\&Delta;P}}{\mathrm{\&mu;a}}---\left(17\right)$

Wherein, A is the cross-sectional area of little sillar, Δ P=P _In-P _Out

When little sillar bottom surface did not have tree lace, the mean permeability of establishing little sillar was K _⊥, according to Darcy formula, the flow Q that the unit interval is passed little sillar is:

$Q=K_{\&perp;}\frac{\mathrm{A\&Delta;P}}{\mathrm{\&mu;a}}---\left(18\right)$

(17), (18) two formulas are divided by and are obtained:

$\frac{K_{\&perp;}^{\&prime;\&prime;}}{K_{\&perp;}}=\frac{Q^{\&prime;\&prime;}}{Q}---\left(19\right)$

Calculate Q by formula (18), obtain Q the mean permeability K of little sillar under the different tree lace width ", just can calculate ", and calculate changes in permeability rate before and after the little sillar gluing thus according to formula (19) by numerical computations:

${\mathrm{\&epsiv;}}_{K\&perp;}^{\&prime;\&prime;}=\frac{K_{\&perp;}^{\&prime;\&prime;}-K_{\&perp;}}{K_{\&perp;}}---\left(20\right).$

24. method for preparing large-scale porous percolating medium as claimed in claim 23 is characterized in that, described step Q12 comprises:

Q121. calculate the parallel effect of little sillar and bond line:

Consider to be parallel to flowing of adhesive surface, the seepage flow zone still is taken as from the first little sillar central cross-section AA ' to the second little sillar central cross-section BB ', the first little sillar, bond line and this three parts percolating medium of the second little sillar form relation in parallel at this moment, because tree lace is impervious, the barrier effect of supposing tree lace makes that the permeability that is parallel to adhesive surface in the adhesive surface slit is 0;

If Parallel Dielectric is K ' at the mean permeability that is parallel to adhesive surface _||, can consider the rock mass permeability that is parallel to adhesive surface that adhesive surface influences through simple derivation according to Darcy's law

$K_{\left|\right|}^{\&prime;}=(1-\frac{b}{a+b})\frac{K_1+K_2}{2}---\left(21\right)$

In like manner, the permeability K of sillar in parallel under the desirable binding situation _||For:

$K_{\left|\right|}=\frac{K_1+K_2}{2}---\left(22\right)$

This shows that the influence of adhesive surface reduces the permeability that is parallel to adhesive surface, changes in permeability value Δ K ' _||For

$\mathrm{\&Delta;}{K}_{\left|\right|}^{\&prime;}=-\frac{b}{a+b}\frac{K_1+K_2}{2}---\left(23\right)$

The changes in permeability ε ' that is parallel to adhesive surface _K||For

${\mathrm{\&epsiv;}}_{K\left|\right|}^{\&prime;}=\frac{b}{a+b}---\left(24\right)$

Q122. calculate the guide functions of bond line:

When flow direction was parallel to adhesive surface, bond line had high guide functions, and showing as the rock mass permeability increases; Consider the symmetry in flow field between each bar tree lace, 1/4 zone of getting between two tree laces is studied;

With above-mentioned mobile as two-dimentional flowing process, summit with flow region is the origin of coordinates, is that x, y axle are set up rectangular coordinate system with two sidelines of cross section, supposes that bond line is without hindrance flowing, be that permeability is infinitely great, the non-tree lace zone of then little sillar adhesive surface is isobaric border; As research object, set up the Mathematical Modeling of steady seepage with aforementioned little sillar 1/4 zone:

$\frac{{\&PartialD;}^{2}P}{\&PartialD;x^2}+\frac{{\&PartialD;}^{2}P}{\&PartialD;y^2}=0---\left(25\right)$

$\left\{\begin{array}{c}P(x,y){|}_{x=\mathrm{0,0}\&le;y\&le;a/2}=P_{\mathrm{in}}\\ P(x,y){|}_{0\&le;x\&le;w,y=0}=P_{\mathrm{in}}\\ P(x,y){|}_{x=h,d\&le;y\&le;a/2}=P_{\mathrm{out}}\end{array}\right.---\left(26\right)$

$\left\{\begin{array}{c}\frac{\&PartialD;P}{\&PartialD;x}{|}_{0\&le;y\&le;d,x=w}=0\\ \frac{\&PartialD;P}{\&PartialD;y}{|}_{w\&le;x\&le;h,y=d}=0\\ \frac{\&PartialD;P}{\&PartialD;y}{|}_{0\&le;x\&le;h,y=a/2}=0\end{array}\right.---\left(27\right)$

Above Mathematical Modeling adopts numerical method to carry out difference discrete and finds the solution, prepare a computer program at last and finish computational process: at first try to achieve the seepage field pressure distribution during calculating, try to achieve the seepage velocity of the port of export again according to Darcy formula, and obtain passing the unit interval flow Q of little sillar thus " _||

Suppose that the mean permeability that above-mentioned little sillar is parallel to adhesive surface is K " _||, can get according to Darcy formula:

$Q_{\left|\right|}^{\&prime;\&prime;}=K_{\left|\right|}^{\&prime;\&prime;}\frac{\mathrm{A\&Delta;P}}{\mathrm{\&mu;a}}---\left(28\right)$

Wherein, A is the cross-sectional area of little sillar, Δ P=P _In-P _Out,

When supposing not have tree lace around little sillar, the mean permeability of little sillar is K _||, according to Darcy formula, the flow Q that the unit interval is passed little sillar is:

$Q=K_{\left|\right|}\frac{\mathrm{A\&Delta;P}}{\mathrm{\&mu;a}}---\left(29\right)$

(28), (29) two formulas are divided by and are obtained:

$\frac{K_{\left|\right|}^{\&prime;\&prime;}}{K_{\left|\right|}}=\frac{Q_{\left|\right|}^{\&prime;\&prime;}}{Q}---\left(30\right)$

Obtain Q by numerical computations " _||, calculate Q by formula (29), just can calculate the mean permeability K of little sillar under the different tree lace width according to formula (30) " _||, and calculate little sillar gluing front and back thus because the changes in permeability rate that the bond line guide functions causes:

${\mathrm{\&epsiv;}}_{K\left|\right|}^{\&prime;\&prime;}=\frac{K_{\left|\right|}^{\&prime;\&prime;}-K_{\left|\right|}}{K_{\left|\right|}}---\left(31\right).$

25. method for preparing large-scale porous percolating medium as claimed in claim 24 is characterized in that, the permeability variation that is parallel to adhesive surface that aforementioned calculation obtains is on duty with the ratio of bond line total length on the adhesive surface with the little sillar length of side.

26. method for preparing large-scale porous percolating medium as claimed in claim 21 is characterized in that, described step Q2 comprises:

If the degree of porosity of little sillar is φ _m, the degree of porosity of adhesive surface is φ _f, little sillar volume is V _m=a ³, little sillar adds that the cumulative volume behind its adhesive surface on every side is:

V＝(a+b) ³≈a ³+3a ²b

Adhesive surface volume V _fEqual cumulative volume and deduct little sillar volume, promptly

V _f＝V-V _m≈3a ²b

By above data and consider b＜＜a, can get the average pore φ in the cumulative volume:

$\mathrm{\&phi;}=\frac{V_m\&CenterDot;{\mathrm{\&phi;}}_m+V_f\&CenterDot;{\mathrm{\&phi;}}_f}{V}={\mathrm{\&phi;}}_m+\frac{3b}{a+3b}({\mathrm{\&phi;}}_f-{\mathrm{\&phi;}}_m)---\left(32\right).$

Images