CN104933269A - Design method for oil and gas pipeline crossing earthquake fault - Google Patents

Abstract

The invention discloses a design method for oil and gas pipeline crossing earthquake fault, and belongs to the technical field of oil and gas pipeline crossing and spanning design. The method comprises the steps that largest strain value calculation math models of an oil and gas pipeline under the action of an earthquake fault are built; according to oil and gas pipeline parameters and earthquake fault parameters, the corresponding calculation math model is selected to calculate the largest strain value of the pipeline under the action of the earthquake fault; the largest strain value is compared with a permissible strain value in the standard specification to check the pipeline strain value. According to the design method for oil and gas pipeline crossing earthquake fault, by building the simple calculation math models, pipeline design personnel can easily calculate the strain value of pipeline crossing earthquake fault according to the relevant parameters of the pipeline and the earthquake fault, the working efficiency is improved, and the design cycle is shortened.

Description

A kind of oil and gas pipes passes through the method for designing of earthquake fault

Technical field

The present invention relates to oil and gas pipes and wear leap design field, particularly a kind of oil and gas pipes passes through the method for designing of earthquake fault.

Background technology

In the construction and planning of long oil and gas pipeline, pipeline inevitably needs to pass through the high risk zone such as earthquake fault in certain areas, to pipeline damage positive earthquake fault and inverse earthquake fault most serious of all.In order to ensure the safe operation of pipeline, needing the stress according to pipeline during generation tomography and (or) strain regime when designing, making rational design proposal.

When carrying out the design of Pipeline Crossing Program earthquake fault, finite element method (such as: ANSYS, ABAQUS software etc. based on finite element method) is usually adopted to calculate the dependent variable of pipeline under forward and inverse seismogenic faulting.Adopt Finite element arithmetic, to need abstract for concrete engineering problem for mechanical model, in finite element software, set up mechanical model and solve calculating.But, this finite element method has very strong specific aim, need make concrete analyses of concrete problems, model is more difficult general, design cycle is longer, and FEM (finite element) calculation needs to possess sturdy mechanical knowledge, conventional design personnel are difficult to grasp sufficient mechanical knowledge within the shorter design cycle and complete complicated finite element modeling and calculating; In addition, due to the own characteristic of Finite Element Method and software, be difficult to batch processing and form the result that can add up, therefore the method for designing based on reliability cannot be applied in the design of Pipeline Crossing Program earthquake fault, this is that Pipeline Crossing Program earthquake fault designs technical matters urgently to be resolved hurrily.

Summary of the invention

The problems such as the Modeling Calculation process existed in the process of the dependent variable of pipeline under seismogenic faulting is complicated, the design cycle is long are calculated in order to solve existing employing Finite Element Method, the invention provides the method for designing that a kind of oil and gas pipes passes through earthquake fault, comprising:

Set up the maximum strain amount computational mathematics model of oil and gas pipes under seismogenic faulting;

According to oil and gas pipes parameter and earthquake fault parameter, choose corresponding computational mathematics model, calculate the maximum strain amount of pipeline under seismogenic faulting;

Permission dependent variable in described maximum strain amount and standard criterion is contrasted, checks pipeline strain amount.

The described step setting up the maximum strain amount computational mathematics model of oil and gas pipes under seismogenic faulting specifically comprises:

According to the engineering parameter of pipe parameter and Pipeline Crossing Program earthquake fault, set up the finite element model of Pipeline Crossing Program earthquake fault;

By FEM (finite element) calculation, the engineering parameter of analysis conduit parameter and Pipeline Crossing Program earthquake fault, to the affecting laws of pipeline maximum strain amount, sets up the experimental formula describing pipeline maximum strain amount;

Use nonlinear fitting instrument to carry out matching to the undetermined parameter in described experimental formula, draw the maximum strain amount computational mathematics model of oil and gas pipes under seismogenic faulting.

The maximum strain amount computational mathematics model of pipeline under normal faulting is:

$\mathrm{\ϵ}={\mathrm{Bx}}_1{D}^{x_2}{t}^{x_3}{q_d}^{x_4}{t}_u^{x_5}{f}^{(x_6{\mathrm{\α}}^2+x_7\mathrm{\α}+x_8)}{(q_u/q_d)}^{x_9}(x_{10}{\mathrm{\α}}^2+x_{11}\mathrm{\α}+x_{12})\·(x_{13}{p}^2+x_{14}p+x_{15})({\mathrm{mT}}^2+nT+1)$

Wherein: B is model bias; D is pipe diameter, m; T is pipeline wall thickness, m; F is fault displcement, m; α is co-hade, rad; P is pressure in pipeline, MPa; T is conduit running and the installation temperature difference, DEG C; x ₁, x ₂... x ₁₅and m, n are undetermined coefficient; t _ufor axial soil spring, kN/m;

$t_u=\mathrm{\π}D\left(0.608c-0.123c^2-\frac{0.274c}{c^2+1}+\frac{0.695c}{c^3+1}\right)+\mathrm{\π}DH\mathrm{\γ}\frac{1-\sin \mathrm{\φ}}{2}\tan \left(f_r\mathrm{\φ}\right);$

Q _ufor soil spring straight up, kN/m,

q _u＝2cH+(φ/44)γH ²；

Q _dfor soil spring straight down, kN/m,

$\begin{array}{c}{q}_d=\[\cot \left(\mathrm{\φ}+0.001\right)\]\left\{e^{\mathrm{\π}\tan \left(\mathrm{\φ}+0.001\right)}{\tan }^2\left(45+\frac{\mathrm{\φ}+0.001}{2}\right)-1\right\}cD\\ +e^{\mathrm{\π}\tan \mathrm{\φ}}{\[\tan \left(45+\frac{\mathrm{\φ}}{2}\right)\]}^2\mathrm{\γ}HD+e^{0.18\mathrm{\φ}-2.5}{\mathrm{\γD}}^2/2\end{array};$

C is the feature cohesive strength of backfill soil, kPa;

H is the buried depth of pipe centerline, m; γ is the effective weight of soil, kN/m ³; φ is the angle of internal friction of soil, °; f _rfor the friction factor of pipeline and soil.

The maximum strain amount computational mathematics model of X65 grade of steel pipeline under normal faulting is:

$\begin{array}{c}\mathrm{\ϵ}={\mathrm{Bx}}_1{D}^{x_2}{t}^{x_3}{q_d}^{x_4}{t}_u^{x_5}{f}^{\left(x_6{\mathrm{\α}}^2+x_7\mathrm{\α}+x_8\right)}{\left(q_u/q_d\right)}^{x_9}\left(x_{10}{\mathrm{\α}}^2+x_{11}\mathrm{\α}+x_{12}\right)\\ \left(x_{13}{p}^2+x_{14}p+x_{15}\right)\left({\mathrm{mT}}^2+nT+1\right)\end{array}.$

Wherein: x ₁=-1.0547 × 10 ^-10, x ₂=-0.9715, x ₃=-1.3248, x ₄=0.5005, x ₅=0.6694, x ₆=0.1681, x ₇=-0.3464, x ₈=1.4788, x ₉=0.3686, x ₁₀=1.0000, x ₁₁=-1.2797, x ₁₂=-1.2140, x ₁₃=1.0000, x ₁₄=33.7230, x ₁₅=1.3857 × 10 ³; M=-2 × 10 ^-6, n=-0.0034; Average μ=0.98 ~ 1.04 of B, standard deviation sigma=0.08 ~ 0.10.

The maximum strain amount computational mathematics model of X70 grade of steel pipeline under normal faulting is:

$\begin{array}{c}\mathrm{\ϵ}={\mathrm{Bx}}_1{D}^{x_2}{t}^{x_3}{q_d}^{x_4}{t}_u^{x_5}{f}^{\left(x_6{\mathrm{\α}}^2+x_7\mathrm{\α}+x_8\right)}{\left(q_u/q_d\right)}^{x_9}\left(x_{10}{\mathrm{\α}}^2+x_{11}\mathrm{\α}+x_{12}\right)\\ \left(x_{13}{p}^2+x_{14}p+x_{15}\right)\left({\mathrm{mT}}^2+nT+1\right)\end{array}.$

Wherein: x ₁=-1.8520 × 10 ^-11, x ₂=-1.0353, x ₃=-1.3698, x ₄=0.5500, x ₅=0.7222, x ₆=0.2685, x ₇=-0.5402, x ₈=1.5314, x ₉=0.4010, x ₁₀=1.0000, x ₁₁=-1.3700, x ₁₂=-0.9481, x ₁₃=1.0000, x ₁₄=122.3149, x ₁₅=4.4060 × 10 ³; M=-1.0 × 10 ^-5, n=-3.7 × 10 ^-3; Average μ=0.99 ~ 1.06 of B, standard deviation sigma=0.08 ~ 0.14.

The maximum strain amount computational mathematics model of X80 steel-grade pipeline under normal faulting is:

$\begin{array}{c}\mathrm{\ϵ}={\mathrm{Bx}}_1{D}^{x_2}{t}^{x_3}{q_d}^{x_4}{t}_u^{x_5}{f}^{\left(x_6{\mathrm{\α}}^2+x_7\mathrm{\α}+x_8\right)}{\left(q_u/q_d\right)}^{x_9}\left(x_{10}{\mathrm{\α}}^2+x_{11}\mathrm{\α}+x_{12}\right)\\ \left(x_{13}{p}^2+x_{14}p+x_{15}\right)\left({\mathrm{mT}}^2+nT+1\right)\end{array}.$

Wherein: x ₁=-6.10 × 10 ^-13, x ₂=-1.1743, x ₃=-1.5239, x ₄=1.3854, x ₅=0.5222, x ₆=0.7391, x ₇=-1.3647, x ₈=1.8505, x ₉=0.4669, x ₁₀=1.0000, x ₁₁=-1.7510, x ₁₂=-0.5440, x ₁₃=1.0000, x ₁₄=13.7700, x ₁₅=397.7900; M=3.0 × 10 ^-5, n=-4.2 × 10 ^-3; Average μ=0.98 ~ 1.02 of B, standard deviation sigma=0.10 ~ 0.15.

The maximum strain amount computational mathematics model of pipeline under trap-up effect is:

$\begin{array}{c}\mathrm{\ϵ}={\mathrm{Bx}}_1{D}^{x_2}{t}^{x_3}{q_d}^{x_4}{t}_u^{x_5}{f}^{\left(x_6{\mathrm{\α}}^2+x_7\mathrm{\α}+x_8\right)}{\left(q_u/q_d\right)}^{x_9}\left(x_{10}{\mathrm{\α}}^2+x_{11}\mathrm{\α}+x_{12}\right)\\ \left(x_{13}{p}^2+x_{14}p+x_{15}\right)\left({\mathrm{mT}}^2+nT+1\right)\end{array}.$

Wherein: B is model bias; D is pipe diameter, m; T is pipeline wall thickness, m; F is fault displcement, m; α is co-hade, rad; P is pressure in pipeline, MPa; T is conduit running and the installation temperature difference, DEG C; x ₁, x ₂... x ₁₅and m, n are undetermined coefficient; t _ufor axial soil spring, kN/m;

$t_u=\mathrm{\π}D(0.608c-0.123c^2-\frac{0.274c}{c^2+1}+\frac{0.695c}{c^3+1})+\mathrm{\π}DH\mathrm{\γ}\frac{1-sin\mathrm{\φ}}{2}tan\left(f_r\mathrm{\φ}\right);$

Q _ufor soil spring straight up, kN/m,

q _u＝2cH+(φ/44)γH ²；

Q _dfor soil spring straight down, kN/m,

$\begin{array}{c}{q}_d=\[\cot \left(\mathrm{\φ}+0.001\right)\]\left\{e^{\mathrm{\π}\tan \left(\mathrm{\φ}+0.001\right)}{\tan }^2\left(45+\frac{\mathrm{\φ}+0.001}{2}\right)-1\right\}cD\\ +e^{\mathrm{\π}\tan \mathrm{\φ}}{\[\tan \left(45+\frac{\mathrm{\φ}}{2}\right)\]}^2\mathrm{\γ}HD+e^{0.18\mathrm{\φ}-2.5}{\mathrm{\γD}}^2/2\end{array};$

C is the feature cohesive strength of backfill soil, kPa;

H is the buried depth of pipe centerline, m; γ is the effective weight of soil, kN/m ³; φ is the angle of internal friction of soil, °; f _rfor the friction factor of pipeline and soil.

The maximum strain amount computational mathematics model of X65 grade of steel pipeline under trap-up effect is:

$\begin{array}{c}\mathrm{\ϵ}={\mathrm{Bx}}_1{D}^{x_2}{t}^{x_3}{q_d}^{x_4}{t}_u^{x_5}{f}^{\left(x_6{\mathrm{\α}}^2+x_7\mathrm{\α}+x_8\right)}{\left(q_u/q_d\right)}^{x_9}\left(x_{10}{\mathrm{\α}}^2+x_{11}\mathrm{\α}+x_{12}\right)\\ \left(x_{13}{p}^2+x_{14}p+x_{15}\right)\left({\mathrm{mT}}^2+nT+1\right)\end{array}.$

Wherein: x ₁=1.3553 × 10 ^-7, x ₂=-2.0276, x ₃=-0.9635, x ₄=0.1406, x ₅=1.1783, x ₆=-1.2883, x ₇=2.7800, x ₈=0.7763, x ₉=0.4847, x ₁₀=1.0000, x ₁₁=-1.6844, x ₁₂=0.1586, x ₁₃=1.0000, x ₁₄=1.2164, x ₁₅=93.2065; M=9.0 × 10 ^-5, n=0.0045; Average μ=0.88 ~ 0.94 of B, standard deviation sigma=0.21 ~ 0.25.

The maximum strain amount computational mathematics model of X70 grade of steel pipeline under trap-up effect is:

$\begin{array}{c}\mathrm{\ϵ}={\mathrm{Bx}}_1{D}^{x_2}{t}^{x_3}{q_d}^{x_4}{t}_u^{x_5}{f}^{\left(x_6{\mathrm{\α}}^2+x_7\mathrm{\α}+x_8\right)}{\left(q_u/q_d\right)}^{x_9}\left(x_{10}{\mathrm{\α}}^2+x_{11}\mathrm{\α}+x_{12}\right)\\ \left(x_{13}{p}^2+x_{14}p+x_{15}\right)\left({\mathrm{mT}}^2+nT+1\right)\end{array}.$

Wherein: x ₁=4.5610 × 10 ^-7, x ₂=-1.9170, x ₃=-0.8521, x ₄=0.0988, x ₅=1.0751, x ₆=-0.8988, x ₇=1.6759, x ₈=1.3129, x ₉=0.4586, x ₁₀=1.0000, x ₁₁=-1.6524, x ₁₂=0.0201, x ₁₃=1.0000, x ₁₄=-2.1780, x ₁₅=56.9818; M=1.0 × 10 ^-3, n=1.15 × 10 ^-2; Average μ=0.90 ~ 0.94 of B, standard deviation sigma=0.21 ~ 0.24.

The maximum strain amount computational mathematics model of X80 steel-grade pipeline under trap-up effect is:

$\begin{array}{c}\mathrm{\ϵ}={\mathrm{Bx}}_1{D}^{x_2}{t}^{x_3}{q_d}^{x_4}{t}_u^{x_5}{f}^{\left(x_6{\mathrm{\α}}^2+x_7\mathrm{\α}+x_8\right)}{\left(q_u/q_d\right)}^{x_9}\left(x_{10}{\mathrm{\α}}^2+x_{11}\mathrm{\α}+x_{12}\right)\\ \left(x_{13}{p}^2+x_{14}p+x_{15}\right)\left({\mathrm{mT}}^2+nT+1\right)\end{array}.$

Wherein: x ₁=-1.5633 × 10 ^-10, x ₂=-2.4248, x ₃=-1.9470, x ₄=0.8551, x ₅=-0.1846, x ₆=-9.0065, x ₇=15.1521, x ₈=-1.5886, x ₉=0.7243, x ₁₀=1.0000, x ₁₁=-2.1588, x ₁₂=1.2519, x ₁₃=1.0000, x ₁₄=-12.9800, x ₁₅=9.37 × 10 ²; M=9.0 × 10 ^-5, n=4.5 × 10 ^-3; Average μ=0.88 ~ 0.93 of B, standard deviation sigma=0.23 ~ 0.27.

Oil and gas pipes provided by the invention passes through the method for designing of earthquake fault, by setting up simple computational mathematics model, make pipe design personnel according to the correlation parameter such as pipeline and earthquake fault, just the dependent variable of Pipeline Crossing Program earthquake fault can easily be calculated, improve work efficiency, shorten the design cycle.Computational mathematics model provided by the invention, there is highly versatile, calculate quick, easy to use, efficiency advantages of higher, easily grasped by vast pipe design personnel, and can draw a series of can result statistically, easily the method for designing combined based on reliability is applied in the design of Pipeline Crossing Program earthquake fault.

Accompanying drawing explanation

Fig. 1 is the method for designing process flow diagram that the present embodiment oil and gas pipes passes through earthquake fault.

Embodiment

Below in conjunction with drawings and Examples, technical solution of the present invention is further described.

See Fig. 1, embodiments provide the method for designing that a kind of oil and gas pipes passes through earthquake fault, specifically comprise the steps:

Step 101: set up the maximum strain amount computational mathematics model of oil and gas pipes under seismogenic faulting.

The type of earthquake fault comprises trap-down and trap-up, and construction oil and gas pipes comprises the conventional pipeline grade of steel of X65/X70/X80 tri-kinds, vertical 6 kinds of different computational mathematics models of building together.The present embodiment computational mathematics model specifically adopts constitutive model, i.e. Ramberg-Osgood model.The consistance of constitutive model and tubing is good, and has the wide and computational accuracy advantages of higher of applicability.For common pipe materials, the present embodiment all chooses the floor value of actual tests value to carry out matching to ensure the conservative property of result.

First, adopt ABAQUS finite element software, according to the engineering parameter of pipe parameter and the forward and inverse tomography of Pipeline Crossing Program, set up the finite element model of the forward and inverse tomography of Pipeline Crossing Program.Secondly, by FEM (finite element) calculation, analysis conduit passes through the susceptibility of factor and the affecting laws to pipeline maximum strain amount thereof such as angle, fault displcement, pipe diameter, pipeline wall thickness respectively, and adopts mathematical function to describe its rule.Again, comprehensive each factor, to the affecting laws of pipeline maximum strain amount, supposes the experimental formula description pipeline maximum strain amount.Finally, on the basis of a large amount of result of finite element, use the nonlinear fitting tool box in MATLAB mathematical software to carry out matching to the undetermined parameter in experimental formula, draw computational mathematics model expression.In addition, using result of finite element as reference value, the result of calculation of statistical study computational mathematics model and the ratio of result of finite element, draw average and the standard deviation of model bias.

The present embodiment computational mathematics model is as follows:

1) the maximum strain amount computational mathematics model of pipeline under normal faulting is:

$\begin{array}{c}\mathrm{\ϵ}={\mathrm{Bx}}_1{D}^{x_2}{t}^{x_3}{q_d}^{x_4}{t}_u^{x_5}{f}^{\left(x_6{\mathrm{\α}}^2+x_7\mathrm{\α}+x_8\right)}{\left(q_u/q_d\right)}^{x_9}\left(x_{10}{\mathrm{\α}}^2+x_{11}\mathrm{\α}+x_{12}\right)\\ \left(x_{13}{p}^2+x_{14}p+x_{15}\right)\left({\mathrm{mT}}^2+nT+1\right)\end{array}.$

The maximum strain amount of pipeline under normal faulting is real is maximum stretching strain amount, wherein: B is model bias;

D is pipe diameter, m; T is pipeline wall thickness, m; F is fault displcement, m; α is co-hade, rad;

P is pressure in pipeline, MPa; T is conduit running and the installation temperature difference, DEG C; x ₁, x ₂... x ₁₅and m, n are undetermined coefficient; t _ufor axial soil spring, kN/m;

$t_u=\mathrm{\π}D(0.608c-0.123c^2-\frac{0.274c}{c^2+1}+\frac{0.695c}{c^3+1})+\mathrm{\π}DH\mathrm{\γ}\frac{1-sin\mathrm{\φ}}{2}tan\left(f_r\mathrm{\φ}\right);$

Q _ufor soil spring straight up, kN/m,

q _u＝2cH+(φ/44)γH ²；

Q _dfor soil spring straight down, kN/m,

$\begin{array}{c}{q}_d=\[\cot \left(\mathrm{\φ}+0.001\right)\]\left\{e^{\mathrm{\π}\tan \left(\mathrm{\φ}+0.001\right)}{\tan }^2\left(45+\frac{\mathrm{\φ}+0.001}{2}\right)-1\right\}cD\\ +e^{\mathrm{\π}\tan \mathrm{\φ}}{\[\tan \left(45+\frac{\mathrm{\φ}}{2}\right)\]}^2\mathrm{\γ}HD+e^{0.18\mathrm{\φ}-2.5}{\mathrm{\γD}}^2/2\end{array};$

C is the feature cohesive strength of backfill soil, kPa;

H is the buried depth of pipe centerline, m; γ is the effective weight of soil, kN/m ³; φ is the angle of internal friction of soil, °; f _rfor the friction factor of pipeline and soil.

A) the maximum stretching strain amount computational mathematics model of X65 grade of steel pipeline under normal faulting is:

$\begin{array}{c}\mathrm{\ϵ}={\mathrm{Bx}}_1{D}^{x_2}{t}^{x_3}{q_d}^{x_4}{t}_u^{x_5}{f}^{\left(x_6{\mathrm{\α}}^2+x_7\mathrm{\α}+x_8\right)}{\left(q_u/q_d\right)}^{x_9}\left(x_{10}{\mathrm{\α}}^2+x_{11}\mathrm{\α}+x_{12}\right)\\ \left(x_{13}{p}^2+x_{14}p+x_{15}\right)\left({\mathrm{mT}}^2+nT+1\right)\end{array}.$

Wherein: x ₁=-1.0547 × 10 ^-10, x ₂=-0.9715, x ₃=-1.3248, x ₄=0.5005, x ₅=0.6694, x ₆=0.1681, x ₇=-0.3464, x ₈=1.4788, x ₉=0.3686, x ₁₀=1.0000, x ₁₁=-1.2797, x ₁₂=-1.2140, x ₁₃=1.0000, x ₁₄=33.7230, x ₁₅=1.3857 × 10 ³; M=-2 × 10 ^-6, n=-0.0034; Average μ=0.98 ~ 1.04 of B, standard deviation sigma=0.08 ~ 0.10.

B) the maximum stretching strain amount computational mathematics model of X70 grade of steel pipeline under normal faulting is:

$\begin{array}{c}\mathrm{\ϵ}={\mathrm{Bx}}_1{D}^{x_2}{t}^{x_3}{q_d}^{x_4}{t}_u^{x_5}{f}^{\left(x_6{\mathrm{\α}}^2+x_7\mathrm{\α}+x_8\right)}{\left(q_u/q_d\right)}^{x_9}\left(x_{10}{\mathrm{\α}}^2+x_{11}\mathrm{\α}+x_{12}\right)\\ \left(x_{13}{p}^2+x_{14}p+x_{15}\right)\left({\mathrm{mT}}^2+nT+1\right)\end{array}.$

Wherein: x ₁=-1.8520 × 10 ^-11, x ₂=-1.0353, x ₃=-1.3698, x ₄=0.5500, x ₅=0.7222, x ₆=0.2685, x ₇=-0.5402, x ₈=1.5314, x ₉=0.4010, x ₁₀=1.0000, x ₁₁=-1.3700, x ₁₂=-0.9481, x ₁₃=1.0000, x ₁₄=122.3149, x ₁₅=4.4060 × 10 ³; M=-1.0 × 10 ^-5, n=-3.7 × 10 ^-3; Average μ=0.99 ~ 1.06 of B, standard deviation sigma=0.08 ~ 0.14.

C) the maximum stretching strain amount computational mathematics model of X80 steel-grade pipeline under normal faulting is:

$\begin{array}{c}\mathrm{\ϵ}={\mathrm{Bx}}_1{D}^{x_2}{t}^{x_3}{q_d}^{x_4}{t}_u^{x_5}{f}^{\left(x_6{\mathrm{\α}}^2+x_7\mathrm{\α}+x_8\right)}{\left(q_u/q_d\right)}^{x_9}\left(x_{10}{\mathrm{\α}}^2+x_{11}\mathrm{\α}+x_{12}\right)\\ \left(x_{13}{p}^2+x_{14}p+x_{15}\right)\left({\mathrm{mT}}^2+nT+1\right)\end{array}.$

Wherein: x ₁=-6.10 × 10 ^-13, x ₂=-1.1743, x ₃=-1.5239, x ₄=1.3854, x ₅=0.5222, x ₆=0.7391, x ₇=-1.3647, x ₈=1.8505, x ₉=0.4669, x ₁₀=1.0000, x ₁₁=-1.7510, x ₁₂=-0.5440, x ₁₃=1.0000, x ₁₄=13.7700, x ₁₅=397.7900; M=3.0 × 10 ^-5, n=-4.2 × 10 ^-3; Average μ=0.98 ~ 1.02 of B, standard deviation sigma=0.10 ~ 0.15.

2) the maximum strain amount computational mathematics model of pipeline under trap-up effect is:

$\begin{array}{c}\mathrm{\ϵ}={\mathrm{Bx}}_1{D}^{x_2}{t}^{x_3}{q_d}^{x_4}{t}_u^{x_5}{f}^{\left(x_6{\mathrm{\α}}^2+x_7\mathrm{\α}+x_8\right)}{\left(q_u/q_d\right)}^{x_9}\left(x_{10}{\mathrm{\α}}^2+x_{11}\mathrm{\α}+x_{12}\right)\\ \left(x_{13}{p}^2+x_{14}p+x_{15}\right)\left({\mathrm{mT}}^2+nT+1\right)\end{array}.$

The maximum strain amount of pipeline under trap-up effect is real is maximum compressive strain amount, wherein: B is model bias; D is pipe diameter, m; T is pipeline wall thickness, m; F is fault displcement, m; α is co-hade, rad; P is pressure in pipeline, MPa; T is conduit running and the installation temperature difference, DEG C; x ₁, x ₂... x ₁₅and m, n are undetermined coefficient; t _ufor axial soil spring, kN/m;

$t_u=\mathrm{\π}D\left(0.608c-0.123c^2-\frac{0.274c}{c^2+1}+\frac{0.695c}{c^3+1}\right)+\mathrm{\π}DH\mathrm{\γ}\frac{1-\sin \mathrm{\φ}}{2}\tan \left(f_r\mathrm{\φ}\right);$

Q _ufor soil spring straight up, kN/m,

q _u＝2cH+(φ/44)γH ²；

Q _dfor soil spring straight down, kN/m,

$\begin{array}{c}{q}_d=\[\cot \left(\mathrm{\φ}+0.001\right)\]\left\{e^{\mathrm{\π}\tan \left(\mathrm{\φ}+0.001\right)}{\tan }^2\left(45+\frac{\mathrm{\φ}+0.001}{2}\right)-1\right\}cD\\ +e^{\mathrm{\π}\tan \mathrm{\φ}}{\[\tan \left(45+\frac{\mathrm{\φ}}{2}\right)\]}^2\mathrm{\γ}HD+e^{0.18\mathrm{\φ}-2.5}{\mathrm{\γD}}^2/2\end{array};$

C is the feature cohesive strength of backfill soil, kPa;

H is the buried depth of pipe centerline, m; γ is the effective weight of soil, kN/m ³; φ is the angle of internal friction of soil, °; f _rfor the friction factor of pipeline and soil.

A) the maximum compressive strain amount computational mathematics model of X65 grade of steel pipeline under trap-up effect is:

$\begin{array}{c}\mathrm{\ϵ}={\mathrm{Bx}}_1{D}^{x_2}{t}^{x_3}{q_d}^{x_4}{t}_u^{x_5}{f}^{\left(x_6{\mathrm{\α}}^2+x_7\mathrm{\α}+x_8\right)}{\left(q_u/q_d\right)}^{x_9}\left(x_{10}{\mathrm{\α}}^2+x_{11}\mathrm{\α}+x_{12}\right)\\ \left(x_{13}{p}^2+x_{14}p+x_{15}\right)\left({\mathrm{mT}}^2+nT+1\right)\end{array}.$

Wherein: x ₁=1.3553 × 10 ^-7, x ₂=-2.0276, x ₃=-0.9635, x ₄=0.1406, x ₅=1.1783, x ₆=-1.2883, x ₇=2.7800, x ₈=0.7763, x ₉=0.4847, x ₁₀=1.0000, x ₁₁=-1.6844, x ₁₂=0.1586, x ₁₃=1.0000, x ₁₄=1.2164, x ₁₅=93.2065; M=9.0 × 10 ^-5, n=0.0045; Average μ=0.88 ~ 0.94 of B, standard deviation sigma=0.21 ~ 0.25.

B) the maximum compressive strain amount computational mathematics model of X70 grade of steel pipeline under trap-up effect is:

$\begin{array}{c}\mathrm{\ϵ}={\mathrm{Bx}}_1{D}^{x_2}{t}^{x_3}{q_d}^{x_4}{t}_u^{x_5}{f}^{\left(x_6{\mathrm{\α}}^2+x_7\mathrm{\α}+x_8\right)}{\left(q_u/q_d\right)}^{x_9}\left(x_{10}{\mathrm{\α}}^2+x_{11}\mathrm{\α}+x_{12}\right)\\ \left(x_{13}{p}^2+x_{14}p+x_{15}\right)\left({\mathrm{mT}}^2+nT+1\right)\end{array}.$

Wherein: x ₁=4.5610 × 10 ^-7, x ₂=-1.9170, x ₃=-0.8521, x ₄=0.0988, x ₅=1.0751, x ₆=-0.8988, x ₇=1.6759, x ₈=1.3129, x ₉=0.4586, x ₁₀=1.0000, x ₁₁=-1.6524, x ₁₂=0.0201, x ₁₃=1.0000, x ₁₄=-2.1780, x ₁₅=56.9818; M=1.0 × 10 ^-3, n=1.15 × 10 ^-2; Average μ=0.90 ~ 0.94 of B, standard deviation sigma=0.21 ~ 0.24.

C) the maximum compressive strain amount computational mathematics model of X80 steel-grade pipeline under trap-up effect is:

$\begin{array}{c}\mathrm{\ϵ}={\mathrm{Bx}}_1{D}^{x_2}{t}^{x_3}{q_d}^{x_4}{t}_u^{x_5}{f}^{\left(x_6{\mathrm{\α}}^2+x_7\mathrm{\α}+x_8\right)}{\left(q_u/q_d\right)}^{x_9}\left(x_{10}{\mathrm{\α}}^2+x_{11}\mathrm{\α}+x_{12}\right)\\ \left(x_{13}{p}^2+x_{14}p+x_{15}\right)\left({\mathrm{mT}}^2+nT+1\right)\end{array}.$

Wherein: x ₁=-1.5633 × 10 ^-10, x ₂=-2.4248, x ₃=-1.9470, x ₄=0.8551, x ₅=-0.1846, x ₆=-9.0065, x ₇=15.1521, x ₈=-1.5886, x ₉=0.7243, x ₁₀=1.0000, x ₁₁=-2.1588, x ₁₂=1.2519, x ₁₃=1.0000, x ₁₄=-12.9800, x ₁₅=9.37 × 10 ²; M=9.0 × 10 ^-5, n=4.5 × 10 ^-3; Average μ=0.88 ~ 0.93 of B, standard deviation sigma=0.23 ~ 0.27.

Step 102: according to oil and gas pipes parameter and earthquake fault parameter, chooses corresponding computational mathematics model, calculates the maximum strain amount of pipeline under seismogenic faulting.

The computation process of the present embodiment is described for D711mm/10.3mm wall thickness/X65 grade of steel Pipeline Crossing Program Western Hills tomography below:

1) pipe parameter, as shown in table 1.

Table 1

2) earthquake fault parameter, as shown in table 2.

Table 2

fault name	fault parameter	kinetic property	burst displacement (m) of prediction	soil types
					xishan fault	80 °/N ∠ 50 °	inverse disconnected	level 1.0, vertical 1.0.	soil

3) choose the maximum strain amount computational mathematics model of X65 grade of steel pipeline under trap-up effect, calculate the maximum compressive strain amount of pipeline under trap-up effect.

Wherein, pipe diameter D=0.711m; Pipeline wall thickness t=0.0103m; Fault displcement f=1.414m; Co-hade α=0.872rad; Pressure p=6.4MPa in pipeline; Conduit running and installation temperature difference T=20 DEG C; The buried depth H=2.5m (to tube hub) of pipeline center; Backfill soil is close sand in being, cohesive strength c=0; Effective weight γ=the 18kN/m of soil ³; Internalfrictionangleφ=35 ° of soil; The function coefficient f of pipeline and soil _r=0.6; Axial soil spring t _u=8.23kN/m; Soil spring q straight up _u=89.49kN/m; Soil spring q straight down _d=1268.68kN/m.Above-mentioned parameter is updated to the maximum compressive strain amount computational mathematics model of X65 grade of steel pipeline under trap-up effect, calculates pipeline without the maximum compressive strain amount under interior pressure (p=0) and design pressure (p=6.4Mpa), as shown in table 3.

Table 3

Maximum compressive strain amount	Without the maximum compressive strain amount (%) of interior pressure	The maximum compressive strain amount (%) of design pressure
			Numerical value	2.5	3.82

Step 103: the maximum strain amount of the pipeline calculated under seismogenic faulting and the permission dependent variable in standard criterion are contrasted, checks pipeline strain amount.

In actual applications, the maximum strain amount of the pipeline calculated under seismogenic faulting is contrasted with the permission dependent variable in " oil and gas pipes line project is based on stress design specification " (Q/SY1603-2013).If calculated value is less than permissible value, then show that dependent variable meets code requirement, namely the design proposal of Pipeline Crossing Program earthquake fault meets technical requirement; Otherwise, then need to optimize the design parameters such as pipeline wall thickness, re-start and calculate and check dependent variable, until dependent variable meets code requirement.

The oil and gas pipes that the present embodiment provides passes through the method for designing of earthquake fault, by setting up simple computational mathematics model, make pipe design personnel according to the correlation parameter such as pipeline and earthquake fault, just the dependent variable of Pipeline Crossing Program earthquake fault can easily be calculated, improve work efficiency, shorten the design cycle.The computational mathematics model that the present embodiment provides, there is highly versatile, calculate quick, easy to use, efficiency advantages of higher, easily grasped by vast pipe design personnel, and can draw a series of can result statistically, easily the method for designing combined based on reliability is applied in the design of Pipeline Crossing Program earthquake fault.

Above-described specific embodiment; object of the present invention, technical scheme and beneficial effect are further described; be understood that; the foregoing is only specific embodiments of the invention; be not limited to the present invention; within the spirit and principles in the present invention all, any amendment made, equivalent replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (10)

1. oil and gas pipes passes through a method for designing for earthquake fault, it is characterized in that, comprising:

Set up the maximum strain amount computational mathematics model of oil and gas pipes under seismogenic faulting;

According to oil and gas pipes parameter and earthquake fault parameter, choose corresponding computational mathematics model, calculate the maximum strain amount of pipeline under seismogenic faulting;

Permission dependent variable in described maximum strain amount and standard criterion is contrasted, checks pipeline strain amount.

2. oil and gas pipes as claimed in claim 1 passes through the method for designing of earthquake fault, and it is characterized in that, the described step setting up the maximum strain amount computational mathematics model of oil and gas pipes under seismogenic faulting specifically comprises:

According to the engineering parameter of pipe parameter and Pipeline Crossing Program earthquake fault, set up the finite element model of Pipeline Crossing Program earthquake fault;

By FEM (finite element) calculation, the engineering parameter of analysis conduit parameter and Pipeline Crossing Program earthquake fault, to the affecting laws of pipeline maximum strain amount, sets up the experimental formula describing pipeline maximum strain amount;

Use nonlinear fitting instrument to carry out matching to the undetermined parameter in described experimental formula, draw the maximum strain amount computational mathematics model of oil and gas pipes under seismogenic faulting.

3. oil and gas pipes as claimed in claim 2 passes through the method for designing of earthquake fault, and it is characterized in that, the maximum strain amount computational mathematics model of pipeline under normal faulting is:

$\mathrm{\ϵ}={\mathrm{Bx}}_1{D}^{x_2}{t}^{x_3}{q_d}^{x_4}{t}_u^{x_5}{f}^{(x_6{\mathrm{\α}}^2+x_7\mathrm{\α}+x_8)}{(q_u/q_d)}^{x_9}(x_{10}{\mathrm{\α}}^2+x_{11}\mathrm{\α}+x_{12})\·(x_{13}{p}^2+x_{14}p+x_{15})({\mathrm{mT}}^2+nT+1)$

Wherein: B is model bias; D is pipe diameter, m; T is pipeline wall thickness, m; F is fault displcement, m; α is co-hade, rad; P is pressure in pipeline, MPa; T is conduit running and the installation temperature difference, DEG C; x ₁, x ₂... x ₁₅and m, n are undetermined coefficient; t _ufor axial soil spring, kN/m;

$t_u=\mathrm{\π}D(0.608c-0.123c^2-\frac{0.274c}{c^2+1}+\frac{0.695c}{c^3+1})+\mathrm{\π}DH\mathrm{\γ}\frac{1-sin\mathrm{\φ}}{2}tan\left(f_r\mathrm{\φ}\right);$

Q _ufor soil spring straight up, kN/m,

q _u＝2cH+(φ/44)γH ²；

Q _dfor soil spring straight down, kN/m,

$\begin{array}{c}{q}_d=\[\cot (\mathrm{\φ}+0.001)\]\{e^{\mathrm{\π}\tan (\mathrm{\φ}+0.001)}{\tan }^2(45+\frac{\mathrm{\φ}+0.001}{2})-1\}cD\\ +e^{\mathrm{\π}\tan \mathrm{\φ}}{\[\tan (45+\frac{\mathrm{\φ}}{2})\]}^2\mathrm{\γ}HD+e^{0.18\mathrm{\φ}-2.5}{\mathrm{\γD}}^2/2\end{array};$

C is the feature cohesive strength of backfill soil, kPa;

H is the buried depth of pipe centerline, m; γ is the effective weight of soil, kN/m ³; φ is the angle of internal friction of soil, °; f _rfor the friction factor of pipeline and soil.

4. oil and gas pipes as claimed in claim 3 passes through the method for designing of earthquake fault, and it is characterized in that, the maximum strain amount computational mathematics model of X65 grade of steel pipeline under normal faulting is:

$\mathrm{\ϵ}={\mathrm{Bx}}_1{D}^{x_2}{t}^{x_3}{q_d}^{x_4}{t}_u^{x_5}{f}^{(x_6{\mathrm{\α}}^2+x_7\mathrm{\α}+x_8)}{(q_u/q_d)}^{x_9}(x_{10}{\mathrm{\α}}^2+x_{11}\mathrm{\α}+x_{12}).$

(x ₁₃p ²+x ₁₄p+x ₁₅)(mT ²+nT+1)

Wherein: x ₁=-1.0547 × 10 ^-10, x ₂=-0.9715, x ₃=-1.3248, x ₄=0.5005, x ₅=0.6694, x ₆=0.1681, x ₇=-0.3464, x ₈=1.4788, x ₉=0.3686, x ₁₀=1.0000, x ₁₁=-1.2797, x ₁₂=-1.2140, x ₁₃=1.0000, x ₁₄=33.7230, x ₁₅=1.3857 × 10 ³; M=-2 × 10 ^-6, n=-0.0034; Average μ=0.98 ~ 1.04 of B, standard deviation sigma=0.08 ~ 0.10.

5. oil and gas pipes as claimed in claim 3 passes through the method for designing of earthquake fault, and it is characterized in that, the maximum strain amount computational mathematics model of X70 grade of steel pipeline under normal faulting is:

$\mathrm{\ϵ}={\mathrm{Bx}}_1{D}^{x_2}{t}^{x_3}{q_d}^{x_4}{t}_u^{x_5}{f}^{(x_6{\mathrm{\α}}^2+x_7\mathrm{\α}+x_8)}{(q_u/q_d)}^{x_9}(x_{10}{\mathrm{\α}}^2+x_{11}\mathrm{\α}+x_{12}).$

(x ₁₃p ²+x ₁₄p+x ₁₅)(mT ²+nT+1)

Wherein: x ₁=-1.8520 × 10 ^-11, x ₂=-1.0353, x ₃=-1.3698, x ₄=0.5500, x ₅=0.7222, x ₆=0.2685, x ₇=-0.5402, x ₈=1.5314, x ₉=0.4010, x ₁₀=1.0000, x ₁₁=-1.3700, x ₁₂=-0.9481, x ₁₃=1.0000, x ₁₄=122.3149, x ₁₅=4.4060 × 10 ³; M=-1.0 × 10 ^-5, n=-3.7 × 10 ^-3; Average μ=0.99 ~ 1.06 of B, standard deviation sigma=0.08 ~ 0.14.

6. oil and gas pipes as claimed in claim 3 passes through the method for designing of earthquake fault, and it is characterized in that, the maximum strain amount computational mathematics model of X80 steel-grade pipeline under normal faulting is:

$\mathrm{\ϵ}={\mathrm{Bx}}_1{D}^{x_2}{t}^{x_3}{q_d}^{x_4}{t}_u^{x_5}{f}^{(x_6{\mathrm{\α}}^2+x_7\mathrm{\α}+x_8)}{(q_u/q_d)}^{x_9}(x_{10}{\mathrm{\α}}^2+x_{11}\mathrm{\α}+x_{12}).$

(x ₁₃p ²+x ₁₄p+x ₁₅)(mT ²+nT+1)

Wherein: x ₁=-6.10 × 10 ^-13, x ₂=-1.1743, x ₃=-1.5239, x ₄=1.3854, x ₅=0.5222, x ₆=0.7391, x ₇=-1.3647, x ₈=1.8505, x ₉=0.4669, x ₁₀=1.0000, x ₁₁=-1.7510, x ₁₂=-0.5440, x ₁₃=1.0000, x ₁₄=13.7700, x ₁₅=397.7900; M=3.0 × 10 ^-5, n=-4.2 × 10 ^-3; Average μ=0.98 ~ 1.02 of B, standard deviation sigma=0.10 ~ 0.15.

7. oil and gas pipes as claimed in claim 2 passes through the method for designing of earthquake fault, and it is characterized in that, the maximum strain amount computational mathematics model of pipeline under trap-up effect is:

$\mathrm{\ϵ}={\mathrm{Bx}}_1{D}^{x_2}{t}^{x_3}{q_d}^{x_4}{t}_u^{x_5}{f}^{(x_6{\mathrm{\α}}^2+x_7\mathrm{\α}+x_8)}{(q_u/q_d)}^{x_9}(x_{10}{\mathrm{\α}}^2+x_{11}\mathrm{\α}+x_{12}).$

(x ₁₃p ²+x ₁₄p+x ₁₅)(mT ²+nT+1)

Wherein: B is model bias; D is pipe diameter, m; T is pipeline wall thickness, m; F is fault displcement, m; α is co-hade, rad; P is pressure in pipeline, MPa; T is conduit running and the installation temperature difference, DEG C; x ₁, x ₂... x ₁₅and m, n are undetermined coefficient; t _ufor axial soil spring, kN/m;

$t_u=\mathrm{\π}D(0.608c-0.123c^2-\frac{0.274c}{c^2+1}+\frac{0.695c}{c^3+1})+\mathrm{\π}DH\mathrm{\γ}\frac{1-sin\mathrm{\φ}}{2}tan\left(f_r\mathrm{\φ}\right);$

Q _ufor soil spring straight up, kN/m,

q _u＝2cH+(φ/44)γH ²；

Q _dfor soil spring straight down, kN/m,

$\begin{array}{c}{q}_d=\[\cot (\mathrm{\φ}+0.001)\]\{e^{\mathrm{\π}\tan (\mathrm{\φ}+0.001)}{\tan }^2(45+\frac{\mathrm{\φ}+0.001}{2})-1\}cD\\ +e^{\mathrm{\π}\tan \mathrm{\φ}}{\[\tan (45+\frac{\mathrm{\φ}}{2})\]}^2\mathrm{\γ}HD+e^{0.18\mathrm{\φ}-2.5}{\mathrm{\γD}}^2/2\end{array};$

C is the feature cohesive strength of backfill soil, kPa;

H is the buried depth of pipe centerline, m; γ is the effective weight of soil, kN/m ³; φ is the angle of internal friction of soil, °; f _rfor the friction factor of pipeline and soil.

8. oil and gas pipes as claimed in claim 7 passes through the method for designing of earthquake fault, and it is characterized in that, the maximum strain amount computational mathematics model of X65 grade of steel pipeline under trap-up effect is:

$\mathrm{\ϵ}={\mathrm{Bx}}_1{D}^{x_2}{t}^{x_3}{q_d}^{x_4}{t}_u^{x_5}{f}^{(x_6{\mathrm{\α}}^2+x_7\mathrm{\α}+x_8)}{(q_u/q_d)}^{x_9}(x_{10}{\mathrm{\α}}^2+x_{11}\mathrm{\α}+x_{12}).$

(x ₁₃p ²+x ₁₄p+x ₁₅)(mT ²+nT+1)

Wherein: x ₁=1.3553 × 10 ^-7, x ₂=-2.0276, x ₃=-0.9635, x ₄=0.1406, x ₅=1.1783, x ₆=-1.2883, x ₇=2.7800, x ₈=0.7763, x ₉=0.4847, x ₁₀=1.0000, x ₁₁=-1.6844, x ₁₂=0.1586, x ₁₃=1.0000, x ₁₄=1.2164, x ₁₅=93.2065; M=9.0 × 10 ^-5, n=0.0045; Average μ=0.88 ~ 0.94 of B, standard deviation sigma=0.21 ~ 0.25.

9. oil and gas pipes as claimed in claim 7 passes through the method for designing of earthquake fault, and it is characterized in that, the maximum strain amount computational mathematics model of X70 grade of steel pipeline under trap-up effect is:

$\mathrm{\ϵ}={\mathrm{Bx}}_1{D}^{x_2}{t}^{x_3}{q_d}^{x_4}{t}_u^{x_5}{f}^{(x_6{\mathrm{\α}}^2+x_7\mathrm{\α}+x_8)}{(q_u/q_d)}^{x_9}(x_{10}{\mathrm{\α}}^2+x_{11}\mathrm{\α}+x_{12}).$

(x ₁₃p ²+x ₁₄p+x ₁₅)(mT ²+nT+1)

Wherein: x ₁=4.5610 × 10 ^-7, x ₂=-1.9170, x ₃=-0.8521, x ₄=0.0988, x ₅=1.0751, x ₆=-0.8988, x ₇=1.6759, x ₈=1.3129, x ₉=0.4586, x ₁₀=1.0000, x ₁₁=-1.6524, x ₁₂=0.0201, x ₁₃=1.0000, x ₁₄=-2.1780, x ₁₅=56.9818; M=1.0 × 10 ^-3, n=1.15 × 10 ^-2; Average μ=0.90 ~ 0.94 of B, standard deviation sigma=0.21 ~ 0.24.

10. oil and gas pipes as claimed in claim 7 passes through the method for designing of earthquake fault, and it is characterized in that, the maximum strain amount computational mathematics model of X80 steel-grade pipeline under trap-up effect is:

$\mathrm{\ϵ}={\mathrm{Bx}}_1{D}^{x_2}{t}^{x_3}{q_d}^{x_4}{t}_u^{x_5}{f}^{(x_6{\mathrm{\α}}^2+x_7\mathrm{\α}+x_8)}{(q_u/q_d)}^{x_9}(x_{10}{\mathrm{\α}}^2+x_{11}\mathrm{\α}+x_{12}).$

(x ₁₃p ²+x ₁₄p+x ₁₅)(mT ²+nT+1)

Wherein: x ₁=-1.5633 × 10 ^-10, x ₂=-2.4248, x ₃=-1.9470, x ₄=0.8551, x ₅=-0.1846, x ₆=-9.0065, x ₇=15.1521, x ₈=-1.5886, x ₉=0.7243, x ₁₀=1.0000, x ₁₁=-2.1588, x ₁₂=1.2519, x ₁₃=1.0000, x ₁₄=-12.9800, x ₁₅=9.37 × 10 ²; M=9.0 × 10 ^-5, n=4.5 × 10 ^-3; Average μ=0.88 ~ 0.93 of B, standard deviation sigma=0.23 ~ 0.27.