CN106097134A - A kind of determination method and apparatus of tomography associated fracture development degree - Google Patents

Abstract

The invention provides the determination method and apparatus of a kind of tomography associated fracture development degree, wherein, the method includes: obtain normal stress and the tangential stress of tomography in work area；According to default requirement the network of fault formatted and be divided into multiple volume elements, according to normal stress and tangential stress, calculate minimum principal stress and the maximum principal stress of each node in multiple volume elements；Minimum principal stress according to each node and maximum principal stress, calculate the density gesture that the tomography associated fracture of each node in multiple volume elements is grown；The density gesture grown according to the tomography associated fracture of each node in multiple volume elements, it is judged that the associated fracture development degree of tomography.In embodiments of the present invention, the density gesture that tomography associated fracture according to each node is grown, judge tomography associated fracture development degree, solve the problem that the determination precision of tomography associated fracture development degree is relatively low, for the method that the prediction offer of tomography associated fracture development degree is quantitative, improve the efficiency of oil-gas exploration and development.

Description

A kind of determination method and apparatus of tomography associated fracture development degree

Technical field

The present invention relates to technical field of geological exploration, particularly to a kind of determination method of tomography associated fracture development degree And device.

Background technology

Tomography is structure common in oil-gas exploration and development, the crack profound influence that its association is grown the distribution of oil gas with Exploitation.Stone Experiments of Machanics research is it has been proved that grow in rock and have substantial amounts of microfissure, under certain stress condition, these Microfissure tip can occur stress to concentrate, and causes microfissure to extend, and forms crack.The geologic body being made up of rock exists Having substantial amounts of microfissure, when tomography produces, it can extend growth, be changed into crack.

But, the determination method for tomography associated fracture development degree is only based on appear crack count or structure at present Making the semi-quantitative analysis of physical modeling, precision is relatively low, and uncertainty is stronger.

For the problem that the determination precision of above-mentioned tomography associated fracture development degree is relatively low, effective solution is the most not yet proposed Certainly scheme.

Summary of the invention

Embodiments provide the determination method and apparatus of a kind of tomography associated fracture development degree, existing to solve The problem that the determination precision of technology interrupting layer associated fracture development degree is relatively low.

Embodiments provide a kind of determination method of tomography associated fracture development degree, including: according to tomography Production conditions and ground stress environment, obtain normal stress and the tangential stress of tomography in work area；According to default requirement by institute State the network of fault to format and be divided into multiple volume elements, according to described normal stress and tangential stress, calculate in the plurality of volume elements each The minimum principal stress of node and maximum principal stress；Should according to minimum principal stress and the maximum master of each node in the plurality of volume elements Power, calculates the density gesture that the tomography associated fracture of each node in the plurality of volume elements is grown；According to each in the plurality of volume elements The density gesture that the tomography associated fracture of individual node is grown, it is judged that the associated fracture development degree of described tomography.

In one embodiment, according to described normal stress and tangential stress, calculate each node in the plurality of volume elements Minimum principal stress and maximum principal stress, including: according to described normal stress and tangential stress, described in Finite element arithmetic The minimum principal stress of each node and maximum principal stress in multiple volume elements.

In one embodiment, calculate the tomography associated fracture of each node in the plurality of volume elements according to below equation to send out The density gesture educated:

Ψ=lg [(σ₁-σ₃)²-8σ_t(σ₁+σ₃)]

Wherein, Ψ represents the density gesture that described tomography associated fracture is grown, σ₁Represent suffered by the surrounding formations of described tomography Maximum principal stress, σ₃Represent the minimum principal stress suffered by the surrounding formations of described tomography, σ_tRepresent the surrounding formations of described tomography Tensile strength.

In one embodiment, described tomography includes at least one of: normal fault, reversed fault and strike-slip fault.

In one embodiment, according to normal stress and the tangential stress of the below equation described normal fault of calculating:

${\mathrm{\σ}}_{nf}=\frac{1}{2}({\mathrm{\σ}}_v+{\mathrm{\σ}}_h)+\frac{1}{2}({\mathrm{\σ}}_v-{\mathrm{\σ}}_h)cos2\mathrm{\α}$

${\mathrm{\τ}}_{nf}=\frac{1}{2}({\mathrm{\σ}}_v-{\mathrm{\σ}}_h)sin2\mathrm{\α}$

Wherein, σ_nfRepresent the normal stress on the fault plane of described normal fault, τ_nfRepresent on the fault plane of described normal fault Tangential stress, σ_vRepresent the vertical crustal stress of described normal fault, σ_hRepresent the minimum main crustal stress of level of described normal fault, α table Show the co-hade of described normal fault.

In one embodiment, according to normal stress and the tangential stress of the below equation described reversed fault of calculating:

${\mathrm{\σ}}_{rf}=\frac{1}{2}({\mathrm{\σ}}_H+{\mathrm{\σ}}_v)-\frac{1}{2}({\mathrm{\σ}}_H-{\mathrm{\σ}}_v)cos2\mathrm{\α}$

${\mathrm{\τ}}_{rf}=\frac{1}{2}({\mathrm{\σ}}_H-{\mathrm{\σ}}_v)sin2\mathrm{\α}$

Wherein, σ_nfRepresent the normal stress on the fault plane of described reversed fault, τ_rfRepresent on the fault plane of described reversed fault Tangential stress, σ_HRepresent the maximum main crustal stress of level of described reversed fault, σ_vRepresent the vertical crustal stress of described reversed fault, α table Show the co-hade of described reversed fault.

In one embodiment, according to normal stress and the tangential stress of the below equation described strike-slip fault of calculating:

${\mathrm{\σ}}_{sf}=\frac{1}{2}({\mathrm{\σ}}_H+{\mathrm{\σ}}_h)-\frac{1}{2}({\mathrm{\σ}}_H-{\mathrm{\σ}}_h)cos2\mathrm{\α}$

${\mathrm{\τ}}_{sf}=\frac{1}{2}({\mathrm{\σ}}_H-{\mathrm{\σ}}_h)sin2\mathrm{\α}$

Wherein, σ_sfRepresent the normal stress on the fault plane of described strike-slip fault, τ_sfRepresent the tomography of described strike-slip fault Tangential stress on face, σ_HRepresent the maximum main crustal stress of level of described strike-slip fault, σ_hRepresent the level of described strike-slip fault Little main crustal stress, α represents the maximum main crustal stress of level of described strike-slip fault and the angle of fault plane.

The embodiment of the present invention additionally provides the determination device of a kind of tomography associated fracture development degree, and this device includes: should Power acquiring unit, for according to the Production conditions of tomography and ground stress environment, obtains the normal stress of tomography in work area and cuts To stress；Principal stress computing unit, is divided into multiple volume elements, according to institute for being formatted by the described network of fault according to default requirement State normal stress and tangential stress, calculate minimum principal stress and the maximum principal stress of each node in the plurality of volume elements；Density Gesture computing unit, for according to the minimum principal stress of each node in the plurality of volume elements and maximum principal stress, calculating described many The density gesture that in individual volume elements, the tomography associated fracture of each node is grown；Development degree of micro cracks in oil judging unit, for according to described The density gesture that in multiple volume elements, the tomography associated fracture of each node is grown, it is judged that the associated fracture development degree of described tomography.

In one embodiment, described principal stress computing unit, according to described normal stress and tangential stress, calculates described The minimum principal stress of each node and maximum principal stress in multiple volume elements, including: described principal stress computing unit is according to described method To stress and tangential stress, should according to minimum principal stress and the maximum master of each node in the plurality of volume elements of Finite element arithmetic Power.

In one embodiment, described density gesture computing unit is specifically for calculating the plurality of volume elements according to below equation In each node tomography associated fracture grow density gesture:

Ψ=lg [(σ₁-σ₃)²-8σ_t(σ₁+σ₃)]

Wherein, Ψ represents the density gesture that described tomography associated fracture is grown, σ₁Represent suffered by the surrounding formations of described tomography Maximum principal stress, σ₃Represent the minimum principal stress suffered by the surrounding formations of described tomography, σ_tRepresent the surrounding formations of described tomography Tensile strength.

In embodiments of the present invention, according to the Production conditions of tomography in work area and ground stress environment, obtain gridding and draw It is divided into the density gesture that the tomography associated fracture of each node of multiple volume elements is grown, and according to each node disconnected in multiple volume elements The density gesture that layer associated fracture is grown, it is judged that tomography associated fracture development degree, solves tomography associated fracture development degree Determine the problem that precision is relatively low, for the method that the prediction offer of tomography associated fracture development degree is quantitative, improve oil-gas exploration The efficiency of exploitation.

Accompanying drawing explanation

Accompanying drawing described herein is used for providing a further understanding of the present invention, constitutes the part of the application, not Constitute limitation of the invention.In the accompanying drawings:

Fig. 1 is the flow chart of the determination method of a kind of tomography associated fracture development degree of the embodiment of the present invention；

Fig. 2 is the tomography stress schematic diagram of the somewhere solid of the embodiment of the present invention；

Fig. 3 is the stress schematic diagram of the normal fault of the embodiment of the present invention；

Fig. 4 is the stress schematic diagram of the reversed fault of the embodiment of the present invention；

Fig. 5 is the stress schematic diagram of the strike-slip fault of the embodiment of the present invention；

Fig. 6 (a) is the somewhere hanging wall principal stress evaluation model schematic of the embodiment of the present invention；

Fig. 6 (b) is the somewhere footwall principal stress evaluation model schematic of the embodiment of the present invention；

Fig. 7 (a) is the somewhere hanging wall density potential function distribution of contours schematic diagram of the embodiment of the present invention；

Fig. 7 (b) is the somewhere footwall density potential function distribution of contours schematic diagram of the embodiment of the present invention；

Fig. 8 is a kind of structured flowchart of the determination device of a kind of tomography associated fracture development degree of the embodiment of the present invention.

Detailed description of the invention

For making the object, technical solutions and advantages of the present invention clearer, below in conjunction with embodiment and accompanying drawing, right The present invention is described in further details.Here, the exemplary embodiment of the present invention and explanation thereof are used for explaining the present invention, but also Not as a limitation of the invention.

In view of the problem that the determination precision of prior art interrupting layer associated fracture development degree is relatively low, inventors herein propose On the basis of the normal stress obtaining tomography in work area and tangential stress, tomography is carried out gridding and is divided into multiple volume elements, Computation partition is the density gesture that the tomography associated fracture corresponding to the tomography of each node of multiple volume elements is grown, finally, according to The density gesture that the tomography associated fracture of each node is grown, it is judged that the associated fracture development degree of tomography.Specifically, such as Fig. 1 institute Show, may comprise steps of:

Step 101: according to Production conditions and the ground stress environment of tomography, obtains the normal stress of tomography in work area and cuts To stress；

Tomography refers to earth's crust stress and ruptures, and the structure of notable relative displacement occurs along plane of fracture both sides sillar.Disconnected The scale of layer, big person's across pitch extends up to thousands of kms, can cut through downwards the earth's crust, is generally made up of many tomographies , referred to as fracture belt；Little person's length is in centimeters, it is seen that in rock sample.

Generally, tomography can be divided into according to the displacement property of tomography: normal fault, reversed fault and strike-slip fault. In actual applications, tomography also has other sorting techniques, and this is not construed as limiting by the application.It is illustrated in figure 2 somewhere solid Tomography stress schematic diagram, wherein, σ_HThe maximum main crustal stress of expression level, σ_hThe minimum main crustal stress of expression level, σ_vRepresent vertically Stress, α represents co-hade.σ_H、σ_hAnd σ_vThese three crustal stress can generate different types of disconnected under different magnitude relationship Layer.Specifically, σ is worked as_v＞ σ_H＞ σ_hTime represent is normal fault；Work as σ_H＞ σ_h＞ σ_vTime represent is reversed fault；Work as σ_H＞ σ_v＞ σ_h Time represent is strike-slip fault.

Introduce normal fault, reversed fault and strike-slip fault and corresponding normal stress and tangential stress separately below.

1) normal fault refers specifically to dish relative drop, the tomography that lower wall rises relatively, and it is mainly by drawing tension With action of gravity formation.Normal fault occurrence is relatively steep, generally more than 45 °.That is: σ_v＞ σ_H＞ σ_h。

It is illustrated in figure 3 the stress schematic diagram of normal fault, according to Production conditions and the ground stress environment of tomography, in conjunction with figure 3 are analyzed obtaining normal stress and the tangential stress of normal fault:

${\mathrm{\σ}}_{nf}=\frac{1}{2}({\mathrm{\σ}}_v+{\mathrm{\σ}}_h)+\frac{1}{2}({\mathrm{\σ}}_v-{\mathrm{\σ}}_h)cos2\mathrm{\α}---\left(1\right)$

${\mathrm{\τ}}_{nf}=\frac{1}{2}({\mathrm{\σ}}_v-{\mathrm{\σ}}_h)sin2\mathrm{\α}---\left(2\right)$

Wherein, σ_nfRepresent the normal stress on the fault plane of normal fault, τ_nfRepresent tangentially should on the fault plane of normal fault Power, σ_vRepresent the vertical crustal stress of normal fault, σ_hRepresenting the minimum main crustal stress of level of normal fault, α represents that the tomography of normal fault inclines Angle.

2) reversed fault refers specifically to dish and relatively rises, lower wall relative drop, the throwing on vertical and horizontal of two dishes The tomography of shadow state in an overlapping.That is: σ_H＞ σ_h＞ σ_v。

It is illustrated in figure 4 the stress schematic diagram of reversed fault, according to Production conditions and the ground stress environment of tomography, in conjunction with figure 4 are analyzed obtaining normal stress and the tangential stress of reversed fault:

${\mathrm{\σ}}_{rf}=\frac{1}{2}({\mathrm{\σ}}_H+{\mathrm{\σ}}_v)-\frac{1}{2}({\mathrm{\σ}}_H-{\mathrm{\σ}}_v)cos2\mathrm{\α}$

${\mathrm{\τ}}_{rf}=\frac{1}{2}({\mathrm{\σ}}_H-{\mathrm{\σ}}_v)sin2\mathrm{\α}$

Wherein, σ_nfRepresent the normal stress on the fault plane of reversed fault, τ_rfRepresent tangentially should on the fault plane of reversed fault Power, σ_HRepresent the maximum main crustal stress of level of reversed fault, σ_vRepresenting the vertical crustal stress of reversed fault, α represents that the tomography of reversed fault inclines Angle.

3) strike-slip fault refers specifically to left dish and right dish does not has OQ t, has relative movement in only the horizontal direction, with Time, the tomography that left dish, right dish lifting displacement is much smaller relative to horizontal displacement.Strike-slip fault inclination angle is generally large, even Uprightly, also the most linearly, it is to produce along upright shear fracture under extrusion stress effect to fault line.That is: σ_H＞ σ_v＞ σ_h。

It is illustrated in figure 5 the stress schematic diagram of strike-slip fault, according to Production conditions and the ground stress environment of tomography, in conjunction with Fig. 5 is analyzed obtaining normal stress and the tangential stress of strike-slip fault:

${\mathrm{\σ}}_{sf}=\frac{1}{2}({\mathrm{\σ}}_H+{\mathrm{\σ}}_h)-\frac{1}{2}({\mathrm{\σ}}_H-{\mathrm{\σ}}_h)cos2\mathrm{\α}$

${\mathrm{\τ}}_{sf}=\frac{1}{2}({\mathrm{\σ}}_H-{\mathrm{\σ}}_h)sin2\mathrm{\α}$

Wherein, σ_sfRepresent the normal stress on the fault plane of strike-slip fault, τ_sfRepresent cutting on the fault plane of strike-slip fault To stress, σ_HRepresent the maximum main crustal stress of level of strike-slip fault, σ_hRepresenting the minimum main crustal stress of level of strike-slip fault, α represents The maximum main crustal stress of the level of strike-slip fault and the angle of fault plane.

Step 102: according to default requirement the described network of fault formatted and be divided into multiple volume elements, according to described normal stress And tangential stress, calculate minimum principal stress and the maximum principal stress of each node in the plurality of volume elements；

After the normal stress obtaining tomography and tangential stress, tomography can be carried out gridding and be divided into multiple volume elements, And according to the minimum principal stress of each node in the multiple volume elements of Finite element arithmetic and maximum principal stress.Specifically, can be to disconnected Layer carries out repeatedly gridding and divides, and asks for the minimum principal stress and of each node after every time dividing respectively according to FInite Element Big principal stress, maximum principal stress and minimum principal stress at same node point reach unanimity in the case of different stress and strain model Time, choose the result as final binning of the gridding dividing condition now.It is of course also possible to use additive method meter Calculating minimum principal stress and the maximum principal stress of each node in multiple volume elements, this is not construed as limiting by the application.

As Fig. 6 (a) show somewhere hanging wall principal stress evaluation model, break as Fig. 6 (b) show somewhere Layer lower wall principal stress evaluation model, wherein, inclined-plane is fault plane, and the active force being perpendicular on fault plane is normal stress, The active force being parallel on fault plane is tangential stress.Specifically, the model cross section in Fig. 6 (a) is trapezoidal, and the upper end is a length of 1000m, go to the bottom a length of 2000m, a length of 1000m of flash, and model is at a length of 1000m in y-axis direction；Model in Fig. 6 (b) Cross section is trapezoidal, a length of 1000m in the upper end, and go to the bottom a length of 2000m, a length of 1000m of flash, and model is in y-axis direction length For 1000m.Respectively the cross section model in Fig. 6 (a) and Fig. 6 (b) is carried out gridding division, ask for according to FInite Element every time The minimum principal stress of each node after division and maximum principal stress, the maximum principal stress at the same node point of tomography and minimum When principal stress reaches unanimity in the case of different stress and strain model, choose gridding dividing condition now as final knot Really.After determining gridding dividing condition, corresponding maximum principal stress and minimum principal stress also determine that.

Step 103: according to the minimum principal stress of each node in the plurality of volume elements and maximum principal stress, calculate described many The density gesture that in individual volume elements, the tomography associated fracture of each node is grown；

In the present embodiment, after the minimum principal stress obtaining each node and maximum principal stress, can be according to following public affairs The density gesture that in the formula multiple volume elements of calculating, the tomography associated fracture of each node is grown:

Ψ=lg [(σ₁-σ₃)²-8σ_t(σ₁+σ₃)] (3)

Wherein, Ψ represents the density gesture that tomography associated fracture is grown, σ₁Represent the maximum master suffered by the surrounding formations of tomography Stress, σ₃Represent the minimum principal stress suffered by surrounding formations of tomography, σ_tRepresent the tensile strength of the surrounding formations of tomography.

Still as a example by above-mentioned area, the maximum main crustal stress σ of the level of this area_HThe minimum main crustal stress σ of=30MPa, level_h =20MPa, vertical crustal stress σ_v=36MPa, i.e. this area are normal fault.First, according to formula (1), formula (2) computed tomography On normal stress and tangential stress, obtain the minimum principal stress of each node further according to Finite element arithmetic and maximum master should Power, and use density potential function, i.e. formula (3) calculates tomography surrounding formations associated fracture growth density, is expressed as density gesture Function distribution of contours figure, as shown in Fig. 7 (a) and 7 (b).

Step 104: the density gesture grown according to the tomography associated fracture of each node in the plurality of volume elements, it is judged that described The associated fracture development degree of tomography.

In the present embodiment, judge that the associated fracture of tomography is sent out according to the density gesture size of each node in multiple volume elements Educating degree, specifically, it may be assumed that the density gesture that tomography associated fracture is grown is the biggest, corresponding tomography associated fracture is more grown, instead It, density gesture is the least, and it is the slowest that corresponding tomography associated fracture is grown.

Based on same inventive concept, the embodiment of the present invention additionally provides the determination of a kind of tomography associated fracture development degree Device, as described in the following examples.Owing to the determination device of tomography associated fracture development degree solves the principle of problem with disconnected The determination method of layer associated fracture development degree is similar, and therefore the enforcement of the determination device of tomography associated fracture development degree is permissible See the enforcement of the determination method of tomography associated fracture development degree, repeat no more in place of repetition.Used below, term " unit " or " module " can realize the software of predetermined function and/or the combination of hardware.Although described by following example Device preferably realizes with software, but hardware, or the realization of the combination of software and hardware also may and be contemplated. Fig. 8 is a kind of structured flowchart of the determination device of the tomography associated fracture development degree of the embodiment of the present invention, as shown in Figure 8, and bag Include: stress acquiring unit 801, principal stress computing unit 802, density gesture computing unit 803, development degree of micro cracks in oil judging unit 804, below this structure is illustrated.

Stress acquiring unit 801, tomography in the Production conditions according to tomography and ground stress environment, acquisition work area Normal stress and tangential stress；

Principal stress computing unit 802, is divided into multiple volume elements, root for being formatted by the described network of fault according to default requirement According to normal stress and tangential stress, calculate minimum principal stress and the maximum principal stress of each node in multiple volume elements；

Density gesture computing unit 803, for according to the minimum principal stress of each node in multiple volume elements and maximum principal stress, Calculate the density gesture that the tomography associated fracture of each node in multiple volume elements is grown；

Development degree of micro cracks in oil judging unit 804, for growing according to the tomography associated fracture of each node in multiple volume elements Density gesture, it is judged that the associated fracture development degree of tomography.

In one embodiment, principal stress computing unit, according to normal stress and tangential stress, calculates the plurality of volume elements In the minimum principal stress of each node and maximum principal stress, including: principal stress computing unit can according to described normal stress and Tangential stress, according to the minimum principal stress of each node in the multiple volume elements of Finite element arithmetic and maximum principal stress.

In one embodiment, density gesture computing unit specifically may be used for calculating in multiple volume elements each according to below equation The density gesture that the tomography associated fracture of individual node is grown:

Ψ=lg [(σ₁-σ₃)²-8σ_t(σ₁+σ₃)]

Wherein, Ψ represents the density gesture that tomography associated fracture is grown, σ₁Represent the maximum master suffered by the surrounding formations of tomography Stress, σ₃Represent the minimum principal stress suffered by surrounding formations of tomography, σ_tRepresent the tensile strength of the surrounding formations of tomography.

In one embodiment, tomography can include but not limited at least one of: normal fault, reversed fault and walk sliding disconnected Layer.

In one embodiment, stress acquiring unit specifically may be used for answering according to the normal direction of below equation calculating normal fault Power and tangential stress:

${\mathrm{\σ}}_{nf}=\frac{1}{2}({\mathrm{\σ}}_v+{\mathrm{\σ}}_h)+\frac{1}{2}({\mathrm{\σ}}_v-{\mathrm{\σ}}_h)cos2\mathrm{\α}$

${\mathrm{\τ}}_{nf}=\frac{1}{2}({\mathrm{\σ}}_v-{\mathrm{\σ}}_h)sin2\mathrm{\α}$

Wherein, σ_nfRepresent the normal stress on the fault plane of normal fault, τ_nfRepresent tangentially should on the fault plane of normal fault Power, σ_vRepresent the vertical crustal stress of normal fault, σ_hRepresenting the minimum main crustal stress of level of normal fault, α represents that the tomography of normal fault inclines Angle.

In one embodiment, stress acquiring unit specifically may be used for answering according to the normal direction of below equation calculating reversed fault Power and tangential stress:

${\mathrm{\σ}}_{rf}=\frac{1}{2}({\mathrm{\σ}}_H+{\mathrm{\σ}}_v)-\frac{1}{2}({\mathrm{\σ}}_H-{\mathrm{\σ}}_v)cos2\mathrm{\α}$

${\mathrm{\τ}}_{rf}=\frac{1}{2}({\mathrm{\σ}}_H-{\mathrm{\σ}}_v)sin2\mathrm{\α}$

Wherein, σ_nfRepresent the normal stress on the fault plane of reversed fault, τ_rfRepresent tangentially should on the fault plane of reversed fault Power, σ_HRepresent the maximum main crustal stress of level of reversed fault, σ_vRepresenting the vertical crustal stress of reversed fault, α represents that the tomography of reversed fault inclines Angle.

In one embodiment, stress acquiring unit specifically may be used for calculating the normal direction of strike-slip fault according to below equation Stress and tangential stress:

${\mathrm{\σ}}_{sf}=\frac{1}{2}({\mathrm{\σ}}_H+{\mathrm{\σ}}_h)-\frac{1}{2}({\mathrm{\σ}}_H-{\mathrm{\σ}}_h)cos2\mathrm{\α}$

${\mathrm{\τ}}_{sf}=\frac{1}{2}({\mathrm{\σ}}_H-{\mathrm{\σ}}_h)sin2\mathrm{\α}$

Wherein, σ_sfRepresent the normal stress on the fault plane of strike-slip fault, τ_sfRepresent cutting on the fault plane of strike-slip fault To stress, σ_HRepresent the maximum main crustal stress of level of strike-slip fault, σ_hRepresenting the minimum main crustal stress of level of strike-slip fault, α represents The maximum main crustal stress of the level of strike-slip fault and the angle of fault plane.

As can be seen from the above description, the embodiment of the present invention achieves following technique effect: according to tomography in work area Production conditions and ground stress environment, obtain gridding be divided into multiple volume elements each node tomography associated fracture grow Density gesture, and according in multiple volume elements each node tomography associated fracture grow density gesture, it is judged that tomography associated fracture Development degree, solves the problem that the determination precision of tomography associated fracture development degree is relatively low, grows journey for tomography associated fracture The prediction of degree provides quantitative method, improves the efficiency of oil-gas exploration and development.

Obviously, those skilled in the art should be understood that each module of the above-mentioned embodiment of the present invention or each step are permissible Realizing with general calculating device, they can concentrate on single calculating device, or is distributed in multiple calculating device On the network formed, alternatively, they can realize with calculating the executable program code of device, it is thus possible to by it Store and perform by calculating device in the storage device, and in some cases, can hold with the order being different from herein Step shown or described by row, or they are fabricated to respectively each integrated circuit modules, or multiple by them Module or step are fabricated to single integrated circuit module and realize.So, the embodiment of the present invention is not restricted to any specific hard Part and software combine.

The foregoing is only the preferred embodiments of the present invention, be not limited to the present invention, for the skill of this area For art personnel, the embodiment of the present invention can have various modifications and variations.All within the spirit and principles in the present invention, made Any modification, equivalent substitution and improvement etc., should be included within the scope of the present invention.

Claims (10)

1. the determination method of a tomography associated fracture development degree, it is characterised in that including:

Production conditions according to tomography and ground stress environment, obtain normal stress and the tangential stress of tomography in work area；

According to default requirement the described network of fault formatted and be divided into multiple volume elements, according to described normal stress and tangential stress, Calculate minimum principal stress and the maximum principal stress of each node in the plurality of volume elements；

According to the minimum principal stress of each node in the plurality of volume elements and maximum principal stress, calculate in the plurality of volume elements each The density gesture that the tomography associated fracture of node is grown；

The density gesture grown according to the tomography associated fracture of each node in the plurality of volume elements, it is judged that the association of described tomography is split Seam development degree.

2. the method for claim 1, it is characterised in that according to described normal stress and tangential stress, calculates described many The minimum principal stress of each node and maximum principal stress in individual volume elements, including:

According to described normal stress and tangential stress, according to the minimum master of each node in the plurality of volume elements of Finite element arithmetic Stress and maximum principal stress.

3. the method for claim 1, it is characterised in that calculate each node in the plurality of volume elements according to below equation Tomography associated fracture grow density gesture:

Ψ=lg [(σ₁-σ₃)²-8σ_t(σ₁+σ₃)]

Wherein, Ψ represents the density gesture that described tomography associated fracture is grown, σ₁Represent the maximum suffered by the surrounding formations of described tomography Principal stress, σ₃Represent the minimum principal stress suffered by the surrounding formations of described tomography, σ_tRepresent the tension of the surrounding formations of described tomography Intensity.

4. the method for claim 1, it is characterised in that described tomography includes at least one of: normal fault, reversed fault And strike-slip fault.

5. method as claimed in claim 4, it is characterised in that according to below equation calculate described normal fault normal stress and Tangential stress:

${\mathrm{\σ}}_{nf}=\frac{1}{2}({\mathrm{\σ}}_v+{\mathrm{\σ}}_h)+\frac{1}{2}({\mathrm{\σ}}_v-{\mathrm{\σ}}_h)cos2\mathrm{\α}$

${\mathrm{\τ}}_{nf}=\frac{1}{2}({\mathrm{\σ}}_v-{\mathrm{\σ}}_h)sin2\mathrm{\α}$

Wherein, σ_nfRepresent the normal stress on the fault plane of described normal fault, τ_nfRepresent cutting on the fault plane of described normal fault To stress, σ_vRepresent the vertical crustal stress of described normal fault, σ_hRepresenting the minimum main crustal stress of level of described normal fault, α represents institute State the co-hade of normal fault.

6. method as claimed in claim 4, it is characterised in that according to below equation calculate described reversed fault normal stress and Tangential stress:

${\mathrm{\σ}}_{rf}=\frac{1}{2}({\mathrm{\σ}}_H+{\mathrm{\σ}}_v)-\frac{1}{2}({\mathrm{\σ}}_H-{\mathrm{\σ}}_v)cos2\mathrm{\α}$

${\mathrm{\τ}}_{rf}=\frac{1}{2}({\mathrm{\σ}}_H-{\mathrm{\σ}}_v)sin2\mathrm{\α}$

Wherein, σ_nfRepresent the normal stress on the fault plane of described reversed fault, τ_rfRepresent cutting on the fault plane of described reversed fault To stress, σ_HRepresent the maximum main crustal stress of level of described reversed fault, σ_vRepresenting the vertical crustal stress of described reversed fault, α represents institute State the co-hade of reversed fault.

7. method as claimed in claim 4, it is characterised in that calculate the normal stress of described strike-slip fault according to below equation And tangential stress:

${\mathrm{\σ}}_{sf}=\frac{1}{2}({\mathrm{\σ}}_H+{\mathrm{\σ}}_h)-\frac{1}{2}({\mathrm{\σ}}_H-{\mathrm{\σ}}_h)cos2\mathrm{\α}$

${\mathrm{\τ}}_{sf}=\frac{1}{2}({\mathrm{\σ}}_H-{\mathrm{\σ}}_h)sin2\mathrm{\α}$

Wherein, σ_sfRepresent the normal stress on the fault plane of described strike-slip fault, τ_sfRepresent on the fault plane of described strike-slip fault Tangential stress, σ_HRepresent the maximum main crustal stress of level of described strike-slip fault, σ_hRepresent the level minimum master of described strike-slip fault Crustal stress, α represents the maximum main crustal stress of level of described strike-slip fault and the angle of fault plane.

8. the determination device of a tomography associated fracture development degree, it is characterised in that including:

Stress acquiring unit, in the Production conditions according to tomography and ground stress environment, acquisition work area, the normal direction of tomography should Power and tangential stress；

Principal stress computing unit, is divided into multiple volume elements, according to described for being formatted by the described network of fault according to default requirement Normal stress and tangential stress, calculate minimum principal stress and the maximum principal stress of each node in the plurality of volume elements；

Density gesture computing unit, for according to the minimum principal stress of each node in the plurality of volume elements and maximum principal stress, meter Calculate the density gesture that the tomography associated fracture of each node in the plurality of volume elements is grown；

Development degree of micro cracks in oil judging unit, close for grow according to the tomography associated fracture of each node in the plurality of volume elements Degree gesture, it is judged that the associated fracture development degree of described tomography.

9. device as claimed in claim 8, it is characterised in that described principal stress computing unit is according to described normal stress and cuts To stress, calculate minimum principal stress and the maximum principal stress of each node in the plurality of volume elements, including:

Described principal stress computing unit is according to described normal stress and tangential stress, according to the plurality of volume elements of Finite element arithmetic In the minimum principal stress of each node and maximum principal stress.

10. device as claimed in claim 8, it is characterised in that described density gesture computing unit is specifically for according to following public affairs The density gesture that in the formula the plurality of volume elements of calculating, the tomography associated fracture of each node is grown:

Ψ=lg [(σ₁-σ₃)²-8σ_t(σ₁+σ₃)]

Wherein, Ψ represents the density gesture that described tomography associated fracture is grown, σ₁Represent the maximum suffered by the surrounding formations of described tomography Principal stress, σ₃Represent the minimum principal stress suffered by the surrounding formations of described tomography, σ_tRepresent the tension of the surrounding formations of described tomography Intensity.