CN114547953B

CN114547953B - Fracturing construction parameter optimization method and system based on optimization design chart

Info

Publication number: CN114547953B
Application number: CN202210441204.3A
Authority: CN
Inventors: 徐世乾; 徐亚娟; 高方方; 冯其红; 李昱垚; 王森; 曾凡辉; 刘彧轩
Original assignee: First Geological Environment Investigation Institute Henan Bureau Of Geo-Exploration & Mineral Development; Henan Aerogeophysical Remote Sensing Center; China University of Petroleum East China; Southwest Petroleum University; Drilling Engineering Research Institute of Sinopec Southwest Petroleum Engineering Co Ltd
Current assignee: First Geological Environment Investigation Institute Henan Bureau Of Geo-Exploration & Mineral Development; Henan Aerogeophysical Remote Sensing Center; China University of Petroleum East China; Southwest Petroleum University; Drilling Engineering Research Institute of Sinopec Southwest Petroleum Engineering Co Ltd
Priority date: 2022-04-26
Filing date: 2022-04-26
Publication date: 2022-07-19
Anticipated expiration: 2042-04-26
Also published as: CN114547953A

Abstract

The invention relates to a fracturing construction parameter optimization method and system based on an optimization design plate, and belongs to the technical field of petroleum development. The method comprises the following steps: classifying target reservoirs of different well regions of a target block to mark out different types of reservoirs; generating different numerical simulation schemes aiming at different types of reservoirs and establishing different fracturing production integrated numerical simulation methods; simulating and calculating the numerical simulation scheme by adopting a fracturing production integrated numerical simulation method to obtain production dynamic data of different numerical simulation schemes; calculating corresponding economic net present values according to the production dynamic data of different numerical simulation schemes; drawing a fracturing construction parameter optimization design chart according to the economic net present values corresponding to different numerical simulation schemes; and performing fracturing construction parameter optimization on the target reservoir according to the fracturing construction parameter optimization design chart, and determining the optimal fracturing construction parameters. By adopting the method, economic benefits can be taken as targets, and fracturing construction parameters can be optimized conveniently and quickly.

Description

Fracturing construction parameter optimization method and system based on optimization design chart

Technical Field

The invention relates to the technical field of petroleum development, in particular to a fracturing construction parameter optimization method and system based on an optimization design plate.

Background

In 2020, the external dependence of China petroleum exceeds 70%, and national energy safety faces serious challenges. Chinese has found abundant shale oil resources in the basins of Quercoll, Songliao, Ordos and the like, and preliminary research shows that the recoverable resource amount is about 30 multiplied by 10⁸-60×10⁸Ton. The shale oil is scientifically and effectively developed, and the shale oil development method has important significance for promoting the upgrading of the theory and the technical level of the petroleum industry in China and ensuring the national energy safety. Optimization of fracturing construction parameters is one of key technologies for realizing efficient development of shale oil.

The invention patent with application number 201911315252.2 provides a method, equipment and a readable storage medium for optimizing fracturing construction parameters. The method increases each geological parameter and each construction parameter of the fractured well in the research area by a preset percentage value, compares the fracture height change rate corresponding to each construction parameter and makes a construction chart, and for the new fractured well in the research area, the fracturing construction parameters can be optimized according to the construction chart so as to reach the highest fracture height. The method needs the information of the fractured well when a plate is constructed, but for a new block which is not fractured, the method cannot establish the plate to guide the design of fracturing construction parameters due to the lack of data. Moreover, the method only focuses on the fracturing height, but the production effect of the actual well is influenced by other parameters such as fracturing reconstruction area, reservoir physical properties and the like, so that the method cannot guarantee optimal development effect and economic benefit.

Disclosure of Invention

The invention aims to provide a fracturing construction parameter optimization method and system based on an optimization design plate, which can conveniently and quickly optimize fracturing construction parameters by taking economic benefits as targets.

In order to achieve the purpose, the invention provides the following scheme:

a fracturing construction parameter optimization method based on an optimization design plate comprises the following steps:

classifying target reservoirs of different well regions of a target block to mark out different types of reservoirs; the different types of reservoirs comprise a homogeneous reservoir, a heterogeneous reservoir, a strong cementing natural fracture development reservoir and a weak cementing natural fracture development reservoir;

generating different numerical simulation schemes aiming at the different types of reservoirs and establishing different fracturing production integrated numerical simulation methods;

performing simulation calculation on the numerical simulation scheme by adopting the fracturing production integrated numerical simulation method to obtain production dynamic data of different numerical simulation schemes; the production dynamic data comprises oil production, gas production and change of water production with time corresponding to different geology and fracturing construction parameters in the different numerical simulation schemes;

calculating economic net present values corresponding to different numerical simulation schemes according to the production dynamic data of the different numerical simulation schemes;

drawing a fracturing construction parameter optimization design chart according to the economic net present values corresponding to the different numerical simulation schemes;

and optimizing the fracturing construction parameters of the target reservoir according to the fracturing construction parameter optimization design chart, and determining the optimal fracturing construction parameters.

Optionally, the classifying the target reservoirs of different well regions of the target block to partition different types of reservoirs includes:

determining the heterogeneous degree of the target reservoir permeability and porosity according to the well logging interpretation data;

identifying the density, the length and the trend of natural fractures by means of a three-dimensional seismic data volume, and determining the development degree of the natural fractures of the target reservoir;

determining the bonding strength of the natural fracture of the target reservoir stratum through a rock core experiment result;

and classifying the target reservoir according to the heterogeneous degree of the target reservoir permeability and porosity, the natural fracture development degree of the target reservoir and the natural fracture cementation strength to mark out different types of reservoirs.

Optionally, the generating different numerical simulation schemes for the different types of reservoirs specifically includes:

randomly generating a first preset number of geological parameter random values by using a multi-point geostatistics method aiming at the different types of reservoirs;

randomly generating a second preset number of fracturing construction parameter random values based on Gaussian distribution aiming at the different types of reservoirs;

and combining the geological parameter random values and/or the fracturing construction parameter random values according to the different types of reservoirs to generate different numerical simulation schemes.

Optionally, the calculating, according to the production dynamic data of the different numerical simulation schemes, the economic net present value corresponding to the different numerical simulation schemes specifically includes:

according to the production dynamic data of the different numerical simulation schemes, adopting a formula

Calculating economic net present values corresponding to different numerical simulation schemes; wherein

Is shown as

Fracturing construction parameters of a numerical simulation scheme, including cluster spacing of perforation clusters

Amount of fracturing fluid injected into each cluster of fractures

Number of fracturing clusters

And viscosity of fracturing fluid

；

Operating parameters for fracturing

The economic net present value of the corresponding numerical simulation scheme;

the total number of time steps;

the current time step number;

is a first

Time corresponding to each time step;

is as follows

Step size of a time step;

the annual interest rate;

the total fracturing stage number of the horizontal well;

is shown as

Stage cracking;

is the crude oil price;

is the natural gas price;

is as follows

Stage crack in the first

Average daily oil production at time step;

is as follows

Stage crack at the second stage

Average daily gas production at time step;

cost of treatment for produced water;

is as follows

Stage crack in the first

Average daily water production at time step;

cost for injected water;

is as follows

Stage crack in the first

Average daily water injection at time step.

Optionally, the drawing of the optimal design chart of the fracturing construction parameters according to the economic net present value corresponding to the different numerical simulation schemes specifically includes:

will be the first

Fracturing construction parameter of numerical simulation scheme

One pair by one set is used as an x axis and a y axis, and the first axis is used as the second axis

Taking the economic net present value corresponding to the numerical simulation scheme as a z-axis, and drawing the fracturing constructionAnd (5) optimally designing the layout by using the parameters.

A fracturing construction parameter optimization system based on an optimal design plate comprises:

the reservoir type division module is used for classifying the target reservoirs of different well regions of the target block and dividing different types of reservoirs; the different types of reservoirs comprise a homogeneous reservoir, a heterogeneous reservoir, a strong cementing natural fracture development reservoir and a weak cementing natural fracture development reservoir;

the numerical simulation scheme and method generation module is used for generating different numerical simulation schemes for the different types of reservoirs and establishing different fracturing production integrated numerical simulation methods;

the numerical simulation module is used for performing simulation calculation on the numerical simulation scheme by adopting the fracturing production integrated numerical simulation method to obtain production dynamic data of different numerical simulation schemes; the production dynamic data comprises oil production, gas production and change of water production with time corresponding to different geology and fracturing construction parameters in the different numerical simulation schemes;

the economic net present value calculation module is used for calculating economic net present values corresponding to different numerical simulation schemes according to the production dynamic data of the different numerical simulation schemes;

the optimal design chart drawing module is used for drawing a fracturing construction parameter optimal design chart according to the economic net present values corresponding to the different numerical simulation schemes;

and the optimal design chart application module is used for optimizing fracturing construction parameters of the target reservoir according to the fracturing construction parameter optimal design chart and determining optimal fracturing construction parameters.

Optionally, the reservoir type division module specifically includes:

the heterogeneous degree analysis unit is used for determining the heterogeneous degree of the target reservoir permeability and the porosity according to the well logging interpretation data;

the natural fracture development degree analysis unit is used for identifying the density, the length and the trend of natural fractures by means of a three-dimensional seismic data volume and determining the natural fracture development degree of the target reservoir;

the natural fracture cementation strength judgment unit is used for determining the natural fracture cementation strength of the target reservoir through a rock core experiment result;

and the reservoir type dividing unit is used for classifying the target reservoir according to the heterogeneous degree of the target reservoir permeability and porosity, the natural fracture development degree of the target reservoir and the natural fracture cementation strength to divide different types of reservoirs.

Optionally, the numerical simulation scheme generating module specifically includes:

the geological parameter generation unit is used for randomly generating a first preset number of geological parameter random values by utilizing a multi-point geostatistics method aiming at the different types of reservoirs;

the fracturing construction parameter generating unit is used for randomly generating a second preset number of fracturing construction parameter random values based on Gaussian distribution aiming at the reservoirs of different types;

and the numerical simulation scheme generation unit is used for combining the geological parameter random values and/or the fracturing construction parameter random values according to different types of reservoirs to generate different numerical simulation schemes.

Optionally, the economic net present value calculating module specifically includes:

the economic net present value calculation unit is used for adopting a formula according to the production dynamic data of the different numerical simulation schemes

Is shown as

Amount of fracturing fluid injected into each cluster of fractures

Number of fracturing clusters

And viscosity of fracturing fluid

；

Operating parameters for fracturing

the total number of time steps;

the current time step number;

is as follows

The time corresponding to each time step;

is as follows

Step size of a time step;

the annual interest rate;

for total fracturing of horizontal wellsA stage number;

is shown as

Stage cracking;

is the crude oil price;

is the natural gas price;

is as follows

Stage crack in the first

Average daily oil production at time step;

is as follows

Stage crack in the first

Average daily gas production at time step;

cost of treatment for produced water;

is as follows

Stage crack in the first

Average daily water production at time step;

cost for injected water;

is as follows

Stage crack in the first

Average daily water injection at time step.

Optionally, the optimal design plate drawing module specifically includes:

an optimal design layout drawing unit for drawing the first layout

Fracturing construction parameter of numerical simulation scheme

And drawing an optimal design chart of the fracturing construction parameters by taking the economic net present value corresponding to the numerical simulation scheme as a z-axis.

According to the specific embodiment provided by the invention, the invention discloses the following technical effects:

the invention provides a fracturing construction parameter optimization method and system based on an optimization design plate, wherein the method comprises the following steps: classifying target reservoirs of different well regions of a target block to mark out different types of reservoirs; the different types of reservoirs comprise a homogeneous reservoir, a heterogeneous reservoir, a strong cementing natural fracture development reservoir and a weak cementing natural fracture development reservoir; generating different numerical simulation schemes aiming at the different types of reservoirs and establishing different fracturing production integrated numerical simulation methods; performing simulation calculation on the numerical simulation scheme by adopting a fracturing production integrated numerical simulation method to obtain production dynamic data of different numerical simulation schemes; the production dynamic data comprises oil production, gas production and change of water production with time corresponding to different geology and fracturing construction parameters in the different numerical simulation schemes; calculating economic net present values corresponding to different numerical simulation schemes according to the production dynamic data of the different numerical simulation schemes; drawing a fracturing construction parameter optimization design chart according to the economic net present values corresponding to the different numerical simulation schemes; and optimizing the fracturing construction parameters of the target reservoir according to the fracturing construction parameter optimization design chart, and determining the optimal fracturing construction parameters. By adopting the method, economic benefits can be taken as targets, and fracturing construction parameters can be optimized conveniently and quickly.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.

FIG. 1 is a flow chart of a fracturing construction parameter optimization method based on an optimization design plate according to the invention;

FIG. 2 is a plot of permeability and porosity fields for a heterogeneous reservoir in an embodiment of the present invention; wherein FIG. 2 (a) is a permeability field plot and FIG. 2 (b) is a porosity field plot;

FIG. 3 is a graph of relative permeability curves and capillary force curves used in an embodiment of the present invention; wherein FIG. 3 (a) is a graph of relative permeability and FIG. 3 (b) is a graph of capillary force;

FIG. 4 is a schematic diagram of a numerical simulation model established for each of four types of reservoirs in an embodiment of the present invention; wherein fig. 4(a) is a schematic diagram of a numerical simulation model established for a homogeneous reservoir, fig. 4(b) is a schematic diagram of a numerical simulation model established for a heterogeneous reservoir, fig. 4(c) is a schematic diagram of a numerical simulation model established for a strong cemented natural fracture development reservoir, and fig. 4(d) is a schematic diagram of a numerical simulation model established for a weak cemented natural fracture development reservoir;

FIG. 5 is a schematic diagram of a fracturing construction parameter optimization design layout established for each of four types of reservoirs in an embodiment of the present invention; wherein fig. 5(a) is a schematic diagram of a fracturing construction parameter optimization design chart established for a homogeneous reservoir, fig. 5(b) is a schematic diagram of a fracturing construction parameter optimization design chart established for a heterogeneous reservoir, fig. 5(c) is a schematic diagram of a fracturing construction parameter optimization design chart established for a strong cementation natural fracture development reservoir, and fig. 5(d) is a schematic diagram of a fracturing construction parameter optimization design chart established for a weak cementation natural fracture development reservoir;

FIG. 6 is a system diagram of a fracturing construction parameter optimization method based on an optimization design plate according to the present invention;

fig. 7 is a schematic structural diagram of a computer device for fracture construction parameter optimization according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In order to make the aforementioned objects, features and advantages of the present invention more comprehensible, the present invention is described in detail with reference to the accompanying drawings and the detailed description thereof.

FIG. 1 is a flow chart of a fracturing construction parameter optimization method based on an optimization design plate according to the present invention. Referring to fig. 1, the method for optimizing fracturing construction parameters based on an optimized design plate of the invention specifically comprises the following steps:

step 101: and classifying the target reservoirs of different well regions of the target block to mark out different types of reservoirs.

And dividing the reservoir types according to the characteristics of different well zones of the target block. Specifically, the heterogeneous degree of reservoir permeability and porosity is analyzed according to the well logging interpretation data. And identifying the density, the length and the trend of the natural fractures by means of the three-dimensional seismic data volume, and analyzing the development degree of the natural fractures of the target reservoir. And judging the bonding strength of the natural fracture through a rock core experiment. Furthermore, the reservoirs of different well regions are divided into four types, namely homogeneous reservoirs, heterogeneous reservoirs, strongly cemented natural fracture development reservoirs and weakly cemented natural fracture development reservoirs.

Therefore, the step 101 of classifying the target reservoirs of different well zones of the target block to separate different types of reservoirs includes:

determining the bonding strength of the natural fractures of the target reservoir through a core experiment result;

Step 102: and generating different numerical simulation schemes aiming at the different types of reservoirs and establishing different fracturing production integrated numerical simulation methods.

After the reservoirs of different well regions are classified, different geological parameters and fracturing construction parameter combinations are designed for the different types of reservoirs, and a required numerical simulation scheme is established. Specifically, the value ranges of geological parameters and fracturing construction parameters of reservoirs of different types in the target block are obtained from the data of the mine field. Within the range, randomly generating a first preset number of geological parameter random values by using a multi-point geostatistics method aiming at different types of reservoirs; and meanwhile, randomly generating a second preset number of fracturing construction parameter random values based on Gaussian distribution. And combining the geological parameter random values and/or the fracturing construction parameter random values to generate different numerical simulation schemes aiming at different types of reservoirs.

In practical applications, the geological parameter categories of homogeneous reservoirs include: porosity value, permeability value, initial oil saturation value, initial gas saturation value, effective reservoir thickness distribution diagram, relative permeability curve, capillary force curve, oil-water viscosity, oil-water compression coefficient, rock Young modulus value, rock Poisson ratio value, Biott coefficient, maximum principal stress direction and magnitude, and minimum principal stress direction and magnitude.

In practical application, the geological parameter category of the heterogeneous reservoir needs to be supplemented with the following geological parameter categories on the basis of the geological parameter category of the homogeneous reservoir: porosity distribution, permeability distribution, initial oil saturation distribution, initial gas saturation distribution, rock Young's modulus distribution, rock Poisson ratio distribution, and Biott coefficient distribution.

In practical application, the geological parameter category of the strong-cementing natural fractured reservoir needs to be supplemented with the following geological parameter categories on the basis of the geological parameter category of the homogeneous reservoir: strong bond natural fracture strike, density, length and bond strength, density, dip and fracture strength of the bedding joint.

In practical application, the geological parameter category of the weakly consolidated natural fractured reservoir needs to be supplemented with the following geological parameter categories on the basis of the geological parameter category of the homogeneous reservoir: the tensile strength and the compressive strength of the rock containing the weakly cemented natural fractures, the development direction of the weakly cemented natural fractures, and the density, the inclination angle and the fracture strength of the bedding fractures.

In practical application, the fracturing construction parameters include: horizontal well position, cluster spacing, interval, perforation azimuth, fracturing fluid discharge, fracturing fluid pumping time and fracturing fluid type.

Therefore, the step 102 generates different numerical simulation schemes for the different types of reservoirs, specifically including:

Specifically, the step 102 of establishing different fracture production integrated numerical simulation methods for the different types of reservoirs includes: the method comprises the steps of dispersing a differential equation of solid deformation by adopting an extended finite element method, dispersing partial differential equation of fluid seepage by adopting a discrete fluid embedded discrete fracture model, describing the interaction between a hydraulic fracture and a strong cemented natural fracture based on an energy release rate criterion, describing the interaction between the hydraulic fracture and a weak cemented natural fracture by adopting a damage model, assembling Jacobian matrixes of fluid and solid differential equations by adopting an automatic differential technology, and solving the Jacobian matrix to be converged by adopting a Newton iteration method to obtain production dynamic data corresponding to a given numerical simulation scheme. And calculating a stress intensity factor of the tip of the main crack by adopting J integral, comparing the stress intensity factor with a critical stress intensity factor, and judging the time and the direction of the main crack expansion. Natural fractures in a reservoir can generally be divided into two categories, namely natural fractures with a greater and lesser degree of consolidation. And when the cementation degree of the natural crack surface is stronger, judging the interaction between the main crack and the strong cementation natural crack by adopting an energy release rate criterion. The propagation criterion assumes that the fracture will propagate toward the direction of maximum energy release rate. When the maximum energy release rate is greater than or equal to the critical value

Hydraulic fractures are subject to propagation. The energy release rate in a certain direction is calculated by the following formula:

（1）

in the formula, in case of a planar stress condition,

(ii) a In the case of an in-plane strain condition,

；

is the Young's modulus of the rock,

；

represents the poisson's ratio of the rock;

and

respectively representing stress intensity factors SIF under the conditions of a mode I and a mode II;

and

is the calculated intermediate parameter. The crossing and steering behavior between hydraulic fractures and natural fractures is through the relative energy release rates (including

And

) Is determined by the size of the sensor. Wherein,

the energy release rate representing the propagation of the fracture through the natural fracture in the direction of the maximum principal stress;

a threshold value representing the rate of energy release when the fracture reaches propagation conditions in the matrix rock;

indicating a fracture steering angle of

The energy release rate of propagation in the direction of the natural fracture;

representing the critical value of the energy release rate at which the fracture propagates along the natural fracture and reaches propagation conditions.

And when the bonding degree of the natural crack surface is weaker, judging whether the weakly bonded natural crack is activated and the damage degree of the weakly bonded natural crack by adopting a damage model. At each time step, the equivalent strain of each matrix mesh is calculated as shown in the following equation (2):

（2）

in the formula,

represents Macaulay brackets. If it is used

Then, then

(ii) a If it is not

Then, then

。

Representing the equivalent strain of the matrix rock mass.

Representing the strain in the direction of maximum or minimum principal stress of the matrix rock mass.

The effect for considering compressive strain less than tensile strain is defined as:

（3）

in the formula,

and

respectively, the tensile and compressive strengths, MPa, of the rock.

The evolution equation of the lesion variable is shown in the following formula (4):

（4）

in the formula,

represents the critical strain, measured by the tensile strength

And Young's modulus

And (6) obtaining.

（5）

（6）

In the formula,

the energy of the crack is shown as,

；

represents the characteristic length, m. To satisfy

Under the conditions of (a) to (b),

the requirements are satisfied:

（7）

whether the rock is damaged or not is judged by judging whether the strain in the main stress direction exceeds a critical value or not

. I.e. if

Then, then

(ii) a If it is used

Then, then

。

Or

Respectively, the maximum strain reached by the direction of maximum or minimum principal stress during deformation of the rock mass

Or

。

Indicating the degree of damage occurring to the matrix rock mass in a certain direction,

or

Indicating the degree of damage occurring to the matrix rock mass in the direction of maximum or minimum principal stress, respectively.

Weakly cemented natural fractures can form fracture zones around the primary fracture, thereby altering the elastic modulus, porosity and permeability of the rock.

Step 103: and performing simulation calculation on the numerical simulation scheme by adopting the fracturing production integrated numerical simulation method to obtain the production dynamic data of different numerical simulation schemes.

After the fracturing production integrated numerical simulation method is established according to the step 102, corresponding production dynamic data is obtained by calculating the numerical simulation scheme, and then the economic net present value is calculated.

According to the numerical simulation scheme constructed in the step 102, different fracturing production integrated numerical simulation methods are adopted to establish numerical simulation models and carry out simulation calculation for different types of reservoirs, specifically, a differential equation of solid deformation is dispersed by adopting an extended finite element method, a partial differential equation of discrete fluid seepage embedded in a discrete fracture model is adopted, a Jacobian matrix of fluid and solid differential equations is assembled by adopting an automatic differential technology, and a non-linear equation set of each time step is solved to be convergent by adopting a Newton iteration method. After the model converges at each time step, the stress intensity factor of the tip of the main crack is obtained by adopting J integral, and the stress intensity factor is compared with the critical stress intensity factor to judge the expansion time and direction of the main crack; judging the interaction of the main crack and the strong cementing natural crack by adopting an energy release rate criterion; judging whether the weakly cemented natural fracture is activated or not and judging the damage degree of the weakly cemented natural fracture by adopting a damage model; and if the crack is expanded, updating the crack grid according to the crack trend, and calculating the next time step to finally obtain the production dynamic data corresponding to the geological and fracturing construction parameters of the fracturing well in the reservoir, namely the change of the oil yield, the gas yield and the water yield along with the time.

Step 104: and calculating economic net present values corresponding to the different numerical simulation schemes according to the production dynamic data of the different numerical simulation schemes.

And carrying out numerical simulation according to the reservoir type to obtain a development effect and calculate an economic net present value. Specifically, the economic net present values corresponding to different simulation schemes are calculated according to the production dynamics obtained by simulation calculation by adopting the following formula:

（8）

（9）

in the formula,

operating parameters for fracturing

Economic net cash of corresponding schemeA value;

the total number of time steps;

the current time step number;

is as follows

The time corresponding to each time step;

is a first

Step size of a time step;

the annual interest rate;

the total fracturing stage number of the horizontal well;

is shown as

Stage cracking;

the crude oil price;

is the price of natural gas;

is as follows

Stage crack in the first

Average daily oil production at time step;

is as follows

Stage crack in the first

Average daily gas production at time step;

treatment costs for produced water;

is as follows

Stage crack in the first

Average daily water production at time step;

cost for injected water;

is as follows

Stage crack in the first

Average daily water injection at time step.

Is shown as

Individual fracturing construction parameters, including cluster spacing of perforating clusters

Amount of fracturing fluid injected into each cluster of fractures

、Number of fracturing clusters

Viscosity of fracturing fluid

。

Therefore, the step 104 of calculating the economic net present value corresponding to the different numerical simulation schemes according to the production dynamic data of the different numerical simulation schemes specifically includes:

Is shown as

Amount of fracturing fluid injected into each cluster of fractures

Number of fracturing clusters

And viscosity of fracturing fluid

；

For fracturing construction parameters

the total number of time steps;

the current time step number;

is as follows

Time corresponding to each time step;

is as follows

Step size of a time step;

the annual interest rate;

the total fracturing stage number of the horizontal well;

is shown as

Stage cracking;

is the crude oil price;

is the natural gas price;

is a first

Stage crack in the first

Average daily oil production at time step;

is as follows

Stage crack in the first

Average daily gas production at time step;

cost of treatment for produced water;

is as follows

Stage crack at the second stage

Average daily water production at time step;

cost for injected water;

is as follows

Stage crack in the first

Average daily water injection at time step.

Step 105: and drawing a fracturing construction parameter optimization design chart according to the economic net present value corresponding to the different numerical simulation schemes.

And establishing a fracturing construction parameter optimization design chart according to the economic net present values of the different schemes. Specifically, the fracturing construction parameters (number of perforation clusters) are determined

Inter-cluster distance

Distribution of fracturing fluid

Viscosity of fracturing fluid

) Grouped pairwise (e.g., first group is perforation cluster number

And fracturing fluid viscosity

) Respectively as the x-axis and the y-axis of a rectangular coordinate system, taking the economic net present value of the corresponding scheme as the z-axis, and aiming at different cluster distances

And fracturing fluid distribution

And (4) value taking, namely fitting and drawing a corresponding fracturing construction parameter optimization design chart by adopting a Surf algorithm. Further, the clusters are spaced apart

And fracturing fluid distribution

Respectively as the x-axis and the y-axis of a rectangular coordinate system, taking the economic net present value of the corresponding scheme as the z-axis, and aiming at different perforation cluster numbers

And fracturing fluid viscosity

And combining, namely fitting and drawing a corresponding fracturing construction parameter optimization design chart by adopting a Surf algorithm.

Therefore, the step 105 of drawing a fracturing construction parameter optimization design chart according to the economic net present value corresponding to the different numerical simulation schemes specifically includes:

will be the first

Fracturing construction parameter of numerical simulation scheme

Step 106: and optimizing the fracturing construction parameters of the target reservoir according to the fracturing construction parameter optimization design chart, and determining the optimal fracturing construction parameters.

And performing fracturing construction parameter optimization design on the target reservoir by adopting the optimization design chart. Specifically, the type of a target reservoir is judged according to well logging interpretation data, a three-dimensional seismic data volume and a core experiment result; and finding out the optimal fracturing construction parameters by utilizing an optimal design chart which accords with the characteristics of the target reservoir stratum according to the fracturing construction parameters to be optimized of the target well. In addition, aiming at the condition that the difference between the target reservoir characteristics and the existing reservoir characteristics is large, a corresponding optimization design chart is reestablished, and then the optimal fracturing construction parameters are found out.

The following illustrates a specific process for optimizing the fracturing construction parameters of the target reservoir by using a chart. For example, the injection amount of each cluster of fracturing fluid is selected first

Equal, fracturing fluid viscosity

Number of perforation clusters at reservoir mean

And cluster pitch

And respectively designing a plate for optimization of the x coordinate and the y coordinate. Determining the number of perforation clusters corresponding to the highest position of the economic net present value in the plate

And cluster pitch

. Further selecting the optimal number of perforation clusters

And cluster spacing

Distribution of fracturing fluid under conditions

And fracturing fluid viscosity

Optimally designing a plate for an x coordinate and a y coordinate respectively, and determining the distribution amount of the fracturing fluid corresponding to the highest position of the economic net present value in the plate

And fracturing fluid viscosity

. Thus, the optimal fracturing construction parameters (the number of perforating clusters) are obtained

Inter-cluster distance

Distribution of fracturing fluid

Viscosity of fracturing fluid

) And the method can be used for guiding the construction design of the fracturing well. In addition, if the fracturing fluid viscosity

And number of perforation clusters

Having been determined prior to construction, only the plate under that condition (i.e. cluster spacing) needs to be found

And fracturing fluid distribution

As an optimization design plate for the x and y axes), selecting the fracturing construction parameter at the highest position of the economic net present value as an optimal parameter.

For reservoirs in other areas, if the permeability and porosity distribution of a non-homogeneous reservoir are different from those of a model corresponding to the existing plate greatly, the permeability and porosity distribution of a target reservoir are used as the input of the fracturing production integrated simulator, the production dynamics is calculated, and then the corresponding plate is drawn and optimized. Similarly, if the natural fracture length, trend, density and other characteristics of the natural fractured reservoir are different from the natural fracture attributes of the model corresponding to the existing chart greatly, the natural fracture characteristics of the target reservoir are used as the input of the fracturing and production integrated numerical simulator, the production dynamic and economic net present values are obtained through calculation, the corresponding optimized design chart is drawn, and optimization is carried out.

The existing chart for the optimal design of fracturing construction parameters is not suitable for a newly developed block, only focuses on the fracturing transformation effect from the aspect of the height of a crack, cannot accurately evaluate the oil well exploitation effect and the economic benefit, is poor in application effect of a mine field, and lacks of practicability. The fracturing construction parameter optimization method based on the optimization design chart can conveniently and quickly optimize fracturing construction parameters by taking economic benefits as targets, thereby providing effective guidance for efficient development of unconventional oil gas such as compact oil, shale oil and the like.

In practical applications, a computer-readable storage medium may be provided, and the computer-readable storage medium may store instructions for causing a machine to execute the method for optimizing fracture construction parameters based on an optimization design plate according to the present invention.

The following describes a specific implementation process of the fracturing construction parameter optimization method based on the optimized design chart according to a specific embodiment of the invention.

In specific implementation, the fracturing construction parameter optimization method based on the optimization design plate comprises the following steps:

step 1: and establishing a simulation scheme required by the numerical simulator for calculation aiming at the target block.

The target block type to be researched is shale oil reservoir, and the reservoir types are divided into four types, including homogeneous reservoir, heterogeneous reservoir, strong-cementing natural fracture reservoir and weak-cementing natural fracture reservoir. And respectively collecting geological data and fracturing construction data of the four reservoir layers, and laying a foundation for establishing a numerical simulation model in the next step. Table 1 shows the relevant physical parameters of the reservoir in specific examples of each reservoir type. The relative permeability curves of the oil phase and the water phase are shown in fig. 3 (a), and the capillary force curve is shown in fig. 3 (b). The initial models for the four types of reservoirs are set up as shown in fig. 4(a), fig. 4(b), fig. 4(c), fig. 4 (d).

Table 1 reservoir physical parameters of shale reservoirs in the specific examples

In the embodiment, the influence of different fracturing construction parameters (including the number of perforating clusters, the cluster spacing and the distribution amount of fracturing fluid) and geological parameters (permeability distribution, porosity distribution, density, trend and length of strong cemented natural fractures, distribution and strength of weak cemented natural fractures) on production dynamics is considered, so that when the numerical reservoir simulation scheme is constructed, the number of perforating clusters, the cluster spacing and the distribution amount of fracturing fluid are changed, and other parameters are kept unchanged. Wherein, the value range of the number of the perforating clusters is 2-5 clusters. The value range of the perforation positions needs to ensure that the perforation positions are in the target oil reservoir, and the minimum distance between the two perforation positions is 5 m. The total injection quantity of the fracturing fluid is constant and is 25.6

. By programming a computer program, 500 different numerical simulation schemes are generated for each type of reservoir under the condition of meeting the reasonable value range of the parameters. One of the numerical simulation schemes for the four types of reservoirs is shown in fig. 4(a), fig. 4(b), fig. 4(c), and fig. 4 (d).

Step 2: and establishing a fracturing production integrated numerical simulation method. The method comprises the steps of dispersing a differential equation of solid deformation by adopting an extended finite element method, dispersing partial differential equation of fluid seepage by adopting an embedded discrete fracture model, assembling a Jacobian matrix of fluid and solid differential equations by adopting an automatic differential technology, and solving a nonlinear equation set of each time step to be convergent by adopting a Newton iteration method. After the model converges at each time step, a stress intensity factor of the tip of the main crack is obtained by adopting J integral and is compared with a critical stress intensity factor, and the expansion opportunity and the direction of the main crack are judged; judging the interaction of the main crack and the strong cementing natural crack by adopting an energy release rate criterion; judging whether the weakly cemented natural fracture is activated or not and judging the damage degree of the weakly cemented natural fracture by adopting a damage model; and if the crack is expanded, updating the crack grid according to the crack trend, and calculating the next time step.

And step 3: and calculating a numerical simulation model by adopting the fracturing production integrated numerical simulation method to obtain oil production and water production simulation results at different moments.

And respectively establishing an oil reservoir numerical simulation model corresponding to each simulation scheme aiming at the four types of reservoir layers. The fracturing construction data is used as an input parameter of a numerical simulation method, numerical simulation research is carried out on each simulation scheme by adopting the fracturing production integrated numerical simulation method, and the water injection amount, the oil production amount and the water production amount at different moments in a preset time period (here, 1 year) are output and stored. And simultaneously storing the fracturing construction parameters corresponding to each simulation scheme.

And 4, step 4: the net economic value for each solution was calculated using the following formula:

among them, annual interest rate

Is 0.1; crude oil price

Is 2500 yuan

(ii) a Cost of treatment of produced water

Is 15 yuan

(ii) a Cost of injected water

Is 15 yuan

. And substituting the production dynamics obtained by the fracturing production integrated numerical simulation into the formula to calculate the economic net current value of each scheme.

And then, respectively taking the cluster spacing and the distribution amount of the fracturing fluid as an x axis and a y axis of a rectangular coordinate system, taking the economic net present value of the corresponding scheme as a z axis, and drawing a fracturing construction parameter optimization design chart. In this example, the number of perforation clusters for a homogeneous, heterogeneous, strong cemented natural fracture reservoir was fixed to 4 clusters. And for the weakly consolidated natural fracture reservoir, the number of perforation clusters and the distribution amount of the fracturing fluid are used as variables to be optimized. The fracturing construction parameter optimization design charts of the homogeneous reservoir, the heterogeneous reservoir, the strong cementing natural fracture reservoir and the weak cementing natural fracture reservoir are shown in the figure 5(a), the figure 5(b), the figure 5(c) and the figure 5 (d).

And 5: and carrying out fracturing construction parameter design on the well to be fractured by utilizing the optimal design chart.

If the heterogeneity of the reservoir around the well to be fractured is not strong, and the average permeability value is about

The average porosity was about 0.1,the optimized design chart of fig. 5(a) can be directly adopted, the designed crack spacing is 10 m, and the injection proportion of the external crack fracturing fluid into 4 clusters of cracks is 45%.

If the heterogeneity of the surrounding reservoir is strong and the permeability and porosity distribution are similar to those of fig. 2 (a) and fig. 2 (b), the optimal design chart of fig. 5(b) can be directly adopted, the fracturing construction parameters corresponding to the maximum economic net present value are found from fig. 5(b), the optimal cluster spacing is 12 m, and the proportion of external fracture fracturing fluid injected into 4 clusters of fractures is 48%.

According to the micro-seismic data volume and core experiment analysis result, if strong cementation natural cracks exist in the reservoir and the distribution is similar to that of the natural cracks in the graph 4(c), the optimal design chart of the graph 5(c) can be directly adopted, fracturing construction parameters corresponding to the maximum economic net present value are found from the graph 5(c), the optimal cluster spacing is 12 m, and the proportion of injecting middle crack fracturing fluid into 3 clusters of cracks is 28%.

If a large number of weakly consolidated natural fractures exist in the reservoir, and the tensile strength of the rock is about 1 MPa, the optimal design chart of FIG. 5(d) can be directly adopted, fracturing construction parameters corresponding to the maximum economic net present value are found from FIG. 5(d), the optimal number of perforation clusters is 3, and the proportion of injected intermediate fracture fracturing fluid is 55%.

The invention provides a fracturing construction parameter optimization method based on an optimization design plate, and also provides a fracturing construction parameter optimization system based on the optimization design plate. Fig. 6 is a system block diagram of a fracturing construction parameter optimization method based on an optimization design plate according to the present invention, and referring to fig. 6, the system includes:

the reservoir type dividing module 601 is used for classifying the target reservoirs of different well regions of the target block and dividing different types of reservoirs; the different types of reservoirs comprise a homogeneous reservoir, a heterogeneous reservoir, a strong cementing natural fracture development reservoir and a weak cementing natural fracture development reservoir;

a numerical simulation scheme and method generation module 602, configured to generate different numerical simulation schemes for the different types of reservoirs and establish different fracturing production integrated numerical simulation methods;

the numerical simulation module 603 is configured to perform simulation calculation on the numerical simulation scheme by using a fracturing production integrated numerical simulation method to obtain production dynamic data of different numerical simulation schemes; the production dynamic data comprises oil production, gas production and change of water production with time corresponding to different geology and fracturing construction parameters in the different numerical simulation schemes;

the economic net present value calculating module 604 is configured to calculate economic net present values corresponding to different numerical simulation schemes according to the production dynamic data of the different numerical simulation schemes;

an optimal design plate drawing module 605, configured to draw a fracturing construction parameter optimal design plate according to the economic net present value corresponding to the different numerical simulation schemes;

and an optimization design plate application module 606, configured to perform fracturing construction parameter optimization on the target reservoir according to the fracturing construction parameter optimization design plate, and determine an optimal fracturing construction parameter.

The reservoir type dividing module 601 specifically includes:

the natural fracture development degree analysis unit is used for identifying the density, the length and the trend of the natural fracture by means of the three-dimensional seismic data volume and determining the natural fracture development degree of the target reservoir stratum;

The numerical simulation scheme generating module 602 specifically includes:

the geological parameter generating unit is used for randomly generating a first preset number of geological parameter random values by utilizing a multi-point geostatistics method aiming at the different types of reservoirs;

The economic net present value calculating module 604 specifically includes:

Is shown as

Amount of fracturing fluid injected into each cluster of fractures

Number of fracturing clusters

And viscosity of fracturing fluid

；

For fracturing construction parameters

the total number of time steps;

the current time step number;

is a first

Time corresponding to each time step;

is as follows

Step size of a time step;

the annual interest rate;

the total fracturing stage number of the horizontal well;

denotes the first

Stage cracking;

the crude oil price;

is the natural gas price;

is as follows

Stage crack in the first

Average daily oil production at time step;

is a first

Stage crack in the first

Average daily gas production at time step;

cost of treatment for produced water;

is as follows

Stage crack in the first

Average daily water production at time step;

cost for injected water;

is as follows

Stage crack in the first

Average daily water injection at time step.

The optimal design plate drawing module 605 specifically includes:

an optimal design layout drawing unit for drawing the first layout

Fracturing construction parameter of numerical simulation scheme

In practical applications, there may be further provided a computer device, which includes a memory, a processor and a computer program stored in the memory and executable on the processor, and when the processor executes the computer program, the processor implements the method for optimizing fracturing construction parameters based on the optimization design plate. Specifically, as shown in fig. 7, the computer device may specifically include an input device 1001, a processor 1002, and a memory 1003. The input device 1001 is specifically used for inputting geological parameters of a target oil reservoir and a reasonable fracturing construction parameter range. The processor 1002 may be specifically configured to design and generate different numerical simulation schemes in batches according to the fracturing construction parameter range; according to the numerical simulation scheme, carrying out numerical simulation research of fracturing production integration, exporting numerical simulation results in batches, and calculating economic net present values corresponding to different schemes; and establishing a fracturing construction parameter optimization design chart, and applying the chart to a target reservoir. The memory 1003 may be specifically configured to store geological parameters, fracturing construction parameters, optimization results, and the like of the target oil reservoir.

In this embodiment, the input device may be one of the main devices for exchanging information between a user and a computer system. The input devices may include a keyboard, mouse, camera, scanner, light pen, handwriting input panel, voice input device, etc.; the input device is used to input raw data and a program for processing the data into the computer. The input device can also acquire and receive data transmitted by other modules, units and devices. The processor may be implemented in any suitable way. For example, the processor may take the form of, for example, a microprocessor or processor and a computer-readable medium that stores computer-readable program code (e.g., software or firmware) executable by the (micro) processor, logic gates, switches, an Application Specific Integrated Circuit (ASIC), a programmable logic controller, an embedded microcontroller, and so forth. The memory may in particular be a memory device used in modern information technology for storing information. The memory may include multiple levels, and in a digital system, memory may be used as long as binary data can be stored; in an integrated circuit, a circuit without a physical form and with a storage function is also called a memory, such as a RAM, a FIFO and the like; in the system, the storage device in physical form is also called a memory, such as a memory bank, a TF card and the like.

In this embodiment, the functions and effects specifically realized by the electronic device may be explained by comparing with other embodiments, and are not described herein again.

In practical applications, a computer-readable storage medium may be provided, and the computer-readable storage medium may store instructions for causing a machine to execute the optimal design method for fracturing construction parameters based on an optimal design plate according to the present invention.

Those skilled in the art will appreciate that all or part of the steps in the method for implementing the above embodiments may be implemented by a program, which is stored in a storage medium and includes several instructions to enable a single chip, a chip, or a processor (processor) to execute all or part of the steps in the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. For the system disclosed by the embodiment, the description is relatively simple because the system corresponds to the method disclosed by the embodiment, and the relevant points can be referred to the method part for description.

The principles and embodiments of the present invention have been described herein using specific examples, which are provided only to help understand the method and the core concept of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.

Claims

1. A fracturing construction parameter optimization method based on an optimization design plate is characterized by comprising the following steps:

the calculating the economic net present value corresponding to the different numerical simulation schemes according to the production dynamic data of the different numerical simulation schemes specifically includes:

Is shown as

Amount of fracturing fluid injected into each cluster of fractures

Number of fracturing clusters

And viscosity of fracturing fluid

；

For fracturing construction parameters

the total number of time steps;

the current time step number;

is as follows

The time corresponding to each time step;

is as follows

Step size of a time step;

the annual interest rate;

the total fracturing stage number of the horizontal well;

is shown as

Stage cracking;

the crude oil price;

is the natural gas price;

is as follows

Stage crack in the first

Average daily oil production at time step;

is as follows

Stage crack in the first

Average daily gas production at time step;

cost of treatment for produced water;

is as follows

Stage crack in the first

Average daily water production at time step;

cost for injected water;

is as follows

Stage crack in the first

Average daily water injection rate of time steps;

2. The method of claim 1, wherein the classifying the target reservoirs for different well regions in the target block into different types of reservoirs comprises:

3. The method according to claim 2, wherein the generating different numerical simulation plans for the different types of reservoirs specifically comprises:

randomly generating a first preset number of geological parameter random values by utilizing a multi-point geostatistics method aiming at the different types of reservoirs;

4. The method according to claim 3, wherein the drawing of the optimal design chart of the fracturing construction parameters according to the economic net present value corresponding to the different numerical simulation schemes specifically comprises:

will be the first

Fracturing construction parameter of numerical simulation scheme

The economic net present value corresponding to the numerical simulation scheme is used as the z-axis to be drawnAnd (5) optimizing and designing the fracturing construction parameters.