CN111189862B - Method, device and system for constructing digital core - Google Patents

Method, device and system for constructing digital core Download PDF

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CN111189862B
CN111189862B CN202010021019.XA CN202010021019A CN111189862B CN 111189862 B CN111189862 B CN 111189862B CN 202010021019 A CN202010021019 A CN 202010021019A CN 111189862 B CN111189862 B CN 111189862B
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成宝洋
李俊键
姜汉桥
张宝瑞
贾洪革
汪绪刚
周福建
吴立新
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China University of Petroleum Beijing
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Abstract

The embodiment of the specification discloses a method, a device and a system for constructing a digital core. The method comprises the steps of carrying out CT scanning on a core sample, and determining a micropore area in the core sample based on the CT scanning result; calculating the porosity of micropores in the micropore area; performing equivalent treatment on a pore region and a micropore region included in the CT scanning result based on the porosity, and establishing a pore network model; calculating the permeability of the pore network model, and judging whether the permeability meets a preset error criterion; and when the permeability is confirmed to meet a preset error criterion, determining the pore network model as the constructed digital core. By utilizing the embodiment of the specification, the constructed digital core can reflect the pore throat structure of the actual core more truly, so that the construction precision of the digital core is improved.

Description

Method, device and system for constructing digital core
Technical Field
The embodiment scheme of the specification belongs to the technical field of rock physics, and particularly relates to a method, a device and a system for constructing a digital core.
Background
Carbonate rock is an important oil and gas reservoir, the reserves of the oil and gas in the world account for 47 percent of the reserves of the oil and gas in the world, and the total output of the oil and gas accounts for 60 percent of the total output of the oil and gas in the world. At present, large carbonate reservoirs discovered in China are Tahe oil fields and Nuqiu oil fields, the oil gas yield and the reserves of the two oil fields are higher than those of a plurality of sandstone reservoirs in China, and the large carbonate reservoirs have great exploitation value. The carbonate rock stratum has more types of reservoir spaces, mainly takes different types of multi-scale cracks, holes and pores as main causes and causes of reservoir bodiesIn contrast, there is a degree of discreteness. The carbonate rock stratum has long deposition period, multiple times of diagenesis action and wide types, so that the anisotropy and the heterogeneity of the carbonate rock stratum are increased. Meanwhile, the development of micron-sized pores, nanometer pores and pores in the carbonate rock shows that the porosity is high and can reach 20 percent, but the permeability is only 0.1 multiplied by 10-3 mu m2Even lower, and often hypo-extra-hypo.
The digital core technology is an effective method for core analysis which is popular in recent years, is widely applied in the field of carbonate rock analysis, and has obtained great success. Digital core modeling methods can be divided into two broad categories: physical experimental methods and numerical reconstruction methods. The physical experiment method comprises the steps of firstly obtaining a plane image of the core by means of high-precision instruments such as a high-power optical microscope, a scanning electron microscope or a CT imager and the like, and then carrying out three-dimensional reconstruction on the plane image to obtain the digital core. The numerical reconstruction method is to extract modeling information through image analysis by means of a small amount of data such as a plane image of the rock core, and then to establish the digital rock core by adopting a certain mathematical method.
At present, a method for establishing a three-dimensional digital core based on Micro-CT is limited by scanning resolution, and cannot identify nano-level and partial micron-level pores, especially more micropores which cannot be identified by conventional Micro-CT exist in carbonate rock, if digital core reconstruction is performed only according to pores identified by scanning images, not only is a large error between the identified porosity and the actual porosity, but also the established digital core cannot represent the actual core, as disclosed in patents CN108267466A and CN 109472112A.
Therefore, a scheme capable of truly reflecting the pore throat structure of the core is urgently needed in the industry.
Disclosure of Invention
The embodiment of the specification aims to provide a method, a device and a system for constructing a digital core, and the constructed digital core can reflect the pore throat structure of an actual core more truly by considering the influence of micropores on a seepage passage, so that the construction precision of the digital core can be improved.
The method, the device, the equipment and the system for constructing the digital core provided by the specification are realized in the following modes:
a method of constructing a digital core, comprising:
performing CT scanning on the core sample, and determining a micropore area in the core sample based on the CT scanning result;
calculating the porosity of micropores in the micropore area;
performing equivalent treatment on a pore region and a micropore region included in the CT scanning result based on the porosity, and establishing a pore network model;
calculating the permeability of the pore network model, and judging whether the permeability meets a preset error criterion;
and when the permeability is confirmed to meet a preset error criterion, determining the pore network model as the constructed digital core.
In another embodiment of the method provided in the present specification, the performing a CT scan on the core sample and determining a micropore area in the core sample based on the CT scan includes:
carrying out CT scanning on the rock core sample to obtain a first scanning result;
performing CT scanning after performing first treatment on the core sample to obtain a second scanning result, wherein the first treatment comprises vacuumizing the core sample and injecting a saturated solution;
and comparing the first scanning result with the second scanning result to determine the micropore area in the rock core sample.
In another embodiment of the method provided herein, the calculating the porosity of the micropores in the microporous region comprises:
calculating the CT value of the micropore area based on the first scanning result according to the following formula:
CTgeneral assembly＝∑CTiφi
Wherein, CTGeneral assemblyCT value, CT, representing the micropore areaiRepresents the CT value, phi, of the i substance in the microporous regioniRepresenting the proportion of i substance in the microporous region, the first scanning result comprising the core samplePerforming a CT scan to obtain results;
calculating the porosity of the micropores in the micropore region according to the following formula based on the CT value of the micropore region and the second scanning result:
CTgeneral assembly＝CTSolutions of×φMicro-pores+CTFramework×(1-φMicro-pores)
Wherein, CTSolutions ofRepresents the CT value, CT, of the solutionFrameworkCT value, phi, representing the skeletonMicro-poresAnd the second scanning result comprises the result obtained by performing CT scanning after the first treatment on the core sample.
In another embodiment of the method provided in this specification, the performing, based on the porosity, equivalent processing on a pore region and a micropore region included in the CT scan result to establish a pore network model includes:
performing equivalent treatment on a pore region included in the CT scanning result by using a spherical pore and a columnar throat by using a maximum sphere algorithm, and establishing an initial pore network model;
performing equivalent treatment on the micropore area in the initial pore network model by using spherical micropores by using a porosity equivalent method;
and connecting the sphere micropores and the sphere pores adjacent to the sphere micropores to establish a pore network model.
In another embodiment of the method provided in this specification, the calculating the permeability of the pore network model and determining whether the permeability meets a preset error criterion includes:
when the permeability is confirmed to not meet a preset error criterion, correcting the pore network model to obtain a corrected pore network model;
and calculating the permeability of the corrected pore network model, and judging whether the permeability of the corrected pore network model meets a preset error criterion.
In another embodiment of the method provided in this specification, the performing a correction process on the pore network model includes:
and corroding the cylinder throat between the sphere micropores and the sphere pores in the pore network model by using a Monte Carlo algorithm.
An apparatus to build a digital core, the apparatus comprising:
the micropore area determining module is used for carrying out CT scanning on the core sample and determining the micropore area in the core sample based on the CT scanning result;
a porosity calculation module for calculating the porosity of the micropores in the micropore area;
the pore network model establishing module is used for performing equivalent treatment on a pore region and a micropore region included in the CT scanning result based on the porosity to establish a pore network model;
the permeability calculation module is used for calculating the permeability of the pore network model and judging whether the permeability meets a preset error criterion;
and the digital core construction module is used for determining the pore network model as the constructed digital core when the permeability is confirmed to meet the preset error criterion.
In another embodiment of the apparatus provided in this specification, the micropore area determining module comprises:
the first scanning unit is used for carrying out CT scanning on the rock core sample to obtain a first scanning result;
the second scanning unit is used for performing CT scanning after the first treatment is performed on the core sample to obtain a second scanning result, wherein the first treatment comprises the steps of vacuumizing the core sample and injecting a saturated solution;
and the micropore area determining unit is used for comparing the first scanning result with the second scanning result and determining the micropore area in the rock core sample.
In another embodiment of the apparatus provided herein, the porosity calculation module includes:
a CT value calculating unit for calculating the CT value of the micropore area according to the following formula based on the first scanning result:
CTgeneral assembly＝∑CTiφi
Wherein, CTGeneral assemblyCT value, CT, representing the micropore areaiRepresents the CT value, phi, of the i substance in the microporous regioniRepresenting the proportion of i substances in the microporous region, wherein the first scanning result comprises a result obtained by performing CT scanning on the core sample;
a porosity calculation unit for calculating the porosity of the micropores in the micropore area according to the following formula based on the CT value of the micropore area and the second scanning result:
CTgeneral assembly＝CTSolutions of×φMicro-pores+CTFramework×(1-φMicro-pores)
Wherein, CTSolutions ofRepresents the CT value, CT, of the solutionFrameworkCT value, phi, representing the skeletonMicro-poresAnd the second scanning result comprises the result obtained by performing CT scanning after the first treatment on the core sample.
In another embodiment of the apparatus provided in this specification, the pore network modeling module includes:
the first equivalent processing unit is used for carrying out equivalent processing on a pore region included in the CT scanning result by using a spherical pore and a columnar throat by using a maximum sphere algorithm to establish an initial pore network model;
the second equivalent processing unit is used for carrying out equivalent processing on the micropore area in the initial pore network model by using a sphere micropore by using a porosity equivalent method;
and the pore network model establishing unit is used for connecting the sphere micropores and the sphere pores adjacent to the sphere micropores to establish a pore network model.
In another embodiment of the apparatus provided in this specification, the permeability calculation module includes:
the correcting unit is used for correcting the pore network model when the permeability is confirmed not to meet the preset error criterion, and obtaining the corrected pore network model;
and the judging unit is used for calculating the permeability of the corrected pore network model and judging whether the permeability of the corrected pore network model meets a preset error criterion.
In another embodiment of the apparatus provided in this specification, the performing a correction process on the pore network model includes:
and the corrosion unit is used for carrying out corrosion treatment on the cylinder throat between the sphere micropores and the sphere pores in the pore network model by utilizing a Monte Carlo algorithm.
An apparatus for constructing a digital core comprising a processor and a memory for storing processor-executable instructions that when executed by the processor implement steps comprising:
performing CT scanning on the core sample, and determining a micropore area in the core sample based on the CT scanning result;
calculating the porosity of micropores in the micropore area;
performing equivalent treatment on a pore region and a micropore region included in the CT scanning result based on the porosity, and establishing a pore network model;
calculating the permeability of the pore network model, and judging whether the permeability meets a preset error criterion;
and when the permeability is confirmed to meet a preset error criterion, determining the pore network model as the constructed digital core.
A system for constructing a digital core comprising at least one processor and a memory storing computer-executable instructions that, when executed by the processor, perform the steps of the method of any one of the method embodiments of the present description.
The specification provides a method, a device and a system for constructing a digital core. In some embodiments, a micropore area and micropore porosity in a core sample are determined according to a CT scanning result, then a digital core is established by using a maximum sphere algorithm and a porosity equivalence method, and finally the established digital core is corrected by using a permeability iteration method, so that the porosity and permeability of the digital core are the same as those of a real core, and the established digital core can reflect the pore throat structure of the real core more truly. By adopting the embodiment provided by the specification, the micropore area which cannot be identified in the prior art is considered, so that the constructed digital core can reflect the pore throat structure of the real core more truly, and the construction precision of the digital core is improved.
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In order to more clearly illustrate the embodiments of the present specification or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, it is obvious that the drawings in the following description are only some embodiments described in the present specification, and for those skilled in the art, other drawings can be obtained according to the drawings without any creative effort.
Fig. 1 is a schematic flow diagram of one embodiment of a method of constructing a digital core provided herein;
FIG. 2 is a schematic representation of the framework, micropores, and pore differentiation provided herein;
FIG. 3 is a schematic diagram of a pore network model provided herein without regard to micropores;
FIG. 4 is a schematic diagram of a pore network model provided herein in view of micropores;
FIG. 5 is a schematic diagram of a pore network model of an equivalent actual core provided herein;
fig. 6 is a block diagram of an embodiment of an apparatus for constructing a digital core provided herein;
fig. 7 is a block diagram of a hardware configuration of an embodiment of a server for building a digital core provided in the present specification.
Detailed Description
In order to make those skilled in the art better understand the technical solutions in the present specification, the technical solutions in the embodiments of the present specification will be clearly and completely described below with reference to the drawings in the embodiments of the present specification, and it is obvious that the described embodiments are only a part of the embodiments in the present specification, and not all of the embodiments. All other embodiments that can be obtained by a person skilled in the art on the basis of one or more embodiments of the present description without inventive step shall fall within the scope of protection of the embodiments of the present description.
At present, a method for establishing a three-dimensional digital core based on Micro-CT is limited by scanning resolution, pores at nano level and partial Micro level cannot be identified, more micropores which cannot be identified by conventional Micro-CT exist in carbonate rock, if digital core reconstruction is carried out only according to the pores identified by scanning images, not only is a larger error between the identified porosity and the actual existence, but also the established digital core cannot represent the actual core,
according to the method, the device and the system for constructing the digital core, the micropore area and the micropore porosity in the core sample are determined according to the CT scanning result, then the digital core is established by using a maximum sphere algorithm and a porosity equivalent method, and finally the established digital core is corrected by using a permeability iteration method, so that the established digital core can reflect the pore throat structure of the real core more truly, errors of the digital core and the real core can be reduced, and the construction precision of the digital core is improved.
The following describes an embodiment of the present disclosure with a specific application scenario as an example. Specifically, fig. 1 is a schematic flow diagram of an embodiment of a method for constructing a digital core provided herein. Although the present specification provides the method steps or apparatus structures as shown in the following examples or figures, more or less steps or modules may be included in the method or apparatus structures based on conventional or non-inventive efforts. In the case of steps or structures which do not logically have the necessary cause and effect relationship, the execution order of the steps or the block structure of the apparatus is not limited to the execution order or the block structure shown in the embodiments or the drawings of the present specification. When the described method or module structure is applied to a device, a server or an end product in practice, the method or module structure according to the embodiment or the figures may be executed sequentially or in parallel (for example, in a parallel processor or multi-thread processing environment, or even in an implementation environment including distributed processing and server clustering).
It should be noted that the following description of the embodiments does not limit the technical solutions in other extensible application scenarios based on the present specification. In particular, in an embodiment of a method for constructing a digital core as shown in fig. 1, the method may include:
s0: and carrying out CT scanning on the core sample, and determining the micropore area in the core sample based on the CT scanning result.
In one embodiment of the present disclosure, a CT scan may be performed on a core sample using X-rays to obtain CT scan results. In the embodiments of the present specification, the scanning result may include a void region, a skeleton region, a micropore region, a low density skeleton, or the like. In the embodiment of the specification, the core can also be scanned by utilizing Micro-CT.
In an embodiment of the present description, the performing a CT scan on the core sample and determining a micropore area in the core sample based on the CT scan may include: carrying out CT scanning on the rock core sample to obtain a first scanning result; performing CT scanning after performing first treatment on the core sample to obtain a second scanning result, wherein the first treatment comprises vacuumizing the core sample and injecting a saturated solution; and comparing the first scanning result with the second scanning result to determine the micropore area in the rock core sample. It is noted that saturated solutions include solutions that increase the contrast of the aqueous phase.
For example, in some implementations, a first CT scan of the dried core may be performed to obtain a first scan image, where the black portion of the first scan image may represent pores, the white portion may represent a skeleton, and the gray portion may represent the presence of a micropore region or a less dense skeleton. The dried core may then be evacuated and then injected into a saturated 30% KI solution to completely fill the pores with water, and a second CT scan (in situ scan) may be performed to obtain a second scan image. Since the 30% KI solution increases the attenuation coefficient of the aqueous phase such that the aqueous phase appears white in CT imaging, the white portion in the second scan image may represent the pores, the black portion may represent the low density skeleton, and the gray portion may represent the skeleton or pores of the micropores. Finally, the images of the two CT scans can be subjected to coincidence comparison, and the gray part of the two CT scans is selected, so that the micropore area is determined. The white, black and gray colors displayed in the scanned image are only for exemplary purposes, and the description is not limited thereto.
It should be noted that the present specification may also perform other scanning times, and the present specification does not limit this. In some embodiments, the micropore area is determined by comparing the results of multiple scans, so that the accuracy of determining the micropore area can be improved, and a basis is provided for constructing a high-precision digital core. In addition, the dried core may be injected with other saturated solutions for enhancing the contrast of water, which is not limited in this specification.
S2: calculating the porosity of micropores in the micropore area.
Wherein porosity is understood to be the ratio of the sum of all the volumes of the pore space in a rock sample to the volume of the rock sample, expressed as a percentage. The greater the total porosity of the reservoir, the greater the pore space in the rock can be accounted for.
In one embodiment of the present disclosure, the calculating the porosity of the micropores in the micropore area may include: calculating a CT value of the micropore area based on the first scanning result; and calculating the porosity of micropores in the micropore area based on the CT value of the micropore area and the second scanning result. The first scanning result may include a result obtained by performing a CT scan on the core sample, the second scanning result may include a result obtained by performing a CT scan on the core sample after performing a first process on the core sample, and the first process may include vacuuming the core sample and injecting a saturated solution.
In some embodiments, the CT value of the micropore area may be calculated based on the first scan result according to the following formula:
CTgeneral assembly＝∑CTiφi (1)
Wherein, CTGeneral assemblyRepresents a microCT value of the hole region, CTiRepresents the CT value, phi, of the i substance in the microporous regioniIndicating the proportion of the i substance in the microporous region.
In some embodiments, the porosity of the micropores in the micropore region may be calculated based on the CT value of the micropore region and the second scan result according to the following formula:
CTgeneral assembly＝CTSolutions of×φMicro-pores+CTFramework×(1-φMicro-pores) (2)
Wherein, CTSolutions ofRepresents the CT value, CT, of the solutionFrameworkCT value, phi, representing the skeletonMicro-poresIndicating the porosity of the micropores.
For example, in some implementation scenarios, the porosity of the micropores may be calculated by using a CT value formula, and the CT value of each pixel point in the CT scan image may be equal to the sum of the product of the CT value of each substance at that point and the volume ratio of that substance, as shown in formula (1). In some embodiments, the dry core material is considered to comprise a matrix and air, and the material after saturated water injection comprises a matrix and water. The volume fraction of the substance is understood as the porosity. In the region of the microholes in the second scan image,
CTgeneral assembly＝CT30% KI solution×φMicro-pores+CTFramework×(1-φMicro-pores)
Wherein, 30 percentKI solutionThe CT value of (2) is the average value of the CT values of the white area scanned for the second time, the CT value of the skeleton is the average value of the CT values of the skeleton area excluding the micropore area in the second scanning area, that is, the average value of the CT values in the black part in the second scanning result, and the total CT value is the average value of the CT values of the micropore area scanned for the second time, so that the porosity of the micropores can be calculated. It should be noted that, since 30% KI water is added in the pore and micropore areas of the second scan, the skeleton area is relatively dark and may not appear black, and in this case, the CT value of the skeleton may be the average of the CT values in the darkest part of the second scan result.
S4: and performing equivalent treatment on the pore region and the micropore region included in the CT scanning result based on the porosity, and establishing a pore network model.
The void network model may also be referred to as a digital core, among others. Equivalent processing is understood to mean the study and processing of actual, complex problems and processes, with equivalent, simple, easy-to-study problems and processes, while ensuring the same results. For example, abstract physical phenomena are represented by simple and easy-to-understand concrete models. For example, the pore region may be represented by a spherical pore and a cylindrical throat, and the pore region may be represented by a spherical pore.
In one embodiment of the present description, the scanned image may include a skeleton region, a micropore region, and a pore region. As shown in fig. 2, fig. 2 is a schematic representation of the framework, micropores, and pore differentiation provided herein. Wherein the black part represents the skeleton region, the gray part represents the micropore region, and the white part represents the pore region.
In an embodiment of the present disclosure, the performing equivalent processing on the pore region and the micropore region included in the CT scanning result based on the porosity to establish a pore network model may include: carrying out equivalent treatment on a pore region included in a CT scanning result by using spherical pores and a columnar throat, and establishing an initial pore network model; performing equivalent treatment on a micropore area in the initial pore network model by using spherical micropores; and connecting the sphere micropores and the sphere pores adjacent to the sphere micropores to establish a pore network model. In some embodiments, a maximum sphere algorithm may be used to perform equivalent processing on a pore region included in a CT scanning result with a sphere pore and a columnar throat, to establish an initial pore network model, then a porosity equivalent method is used to perform equivalent processing on a micropore region in the initial pore network model with a sphere micropore, and finally the sphere micropore and a sphere pore adjacent to the sphere micropore may be connected to establish the pore network model.
For example, in some implementation scenarios, the pore region may be replaced with spherical pores and cylindrical throats using a maximum sphere algorithm, and a pore network model may be initially established. As shown in fig. 3, fig. 3 is a schematic diagram of a pore network model provided in the present specification without considering micropores. Since the micropore area includes both pores and a skeleton, it cannot be distinguished when the scanning resolution accuracy is not sufficient, and therefore, the micropore area can be equivalent to a sphere with equal pore volume. For example, in some embodiments, a sphere representing a pore may be established at the center of each pore region according to the porosity equivalence method according to the calculated porosity of the pore and the volume of each pore region, and the sphere is connected to an adjacent sphere representing the pore, so as to establish a pore network model containing the pores. As shown in fig. 4, fig. 4 is a schematic diagram of a pore network model in consideration of micropores, provided in this specification, where reference numeral (1) denotes a sphere (which may also be referred to as a sphere micropore) equivalent to a micropore, and reference numeral (2) denotes a cylinder (which may also be referred to as a cylinder throat) equivalent to a micropore.
S6: and calculating the permeability of the pore network model, and judging whether the permeability meets a preset error criterion.
S8: and when the permeability is confirmed to meet a preset error criterion, determining the pore network model as the constructed digital core.
The preset error criterion may include that the error is zero, or the error is within a preset range, and the like. The preset range may be set according to an actual scene.
In an embodiment of the present description, after the pore network model is established, the corresponding permeability may be calculated and compared with the permeability calculated according to the actual core sample, so as to ensure that the finally established digital core can reflect the pore throat structure of the real core.
In an embodiment of the present disclosure, the calculating the permeability of the pore network model and determining whether the permeability meets a preset error criterion may include: and when the permeability is confirmed to meet a preset error criterion, determining the pore network model as the constructed digital core. For example, in some implementations, the dried core is vacuumized and then saturated with 30% KI solution, the pores are completely filled with water, the permeability K1 of the core sample is measured, a displacement simulation is performed based on the established pore network model considering micropores to calculate the permeability K2, whether K1 is equal to K2 or not is compared, and if K2 is equal to K1, the obtained pore network model is the final established digital core.
In an embodiment of the present disclosure, the calculating the permeability of the pore network model and determining whether the permeability meets a preset error criterion may include: when the permeability is confirmed to not meet a preset error criterion, correcting the pore network model to obtain a corrected pore network model; and calculating the permeability of the corrected pore network model, and judging whether the permeability of the corrected pore network model meets a preset error criterion. In some embodiments, the performing the correction process on the pore network model may include: and corroding the cylinder throat between the sphere micropores and the sphere pores in the pore network model by using a Monte Carlo algorithm.
For example, in some implementation scenarios, after the dried core is vacuumized, 30% KI solution is saturated, pores are completely filled with water, the permeability K1 is measured, based on the established pore network model considering micropores, displacement simulation is performed to calculate the permeability K2, whether K1 and K2 meet a preset error criterion or not is compared, when the preset error criterion is not met, the number of cylinder throats between the micropores of the sphere and the pores of the sphere can be randomly corroded by a monte carlo algorithm until the preset error criterion is met, and the obtained pore network model is the digital core finally established. As shown in fig. 5, fig. 5 is a schematic diagram of a pore network model of an equivalent actual core provided in the present specification, wherein the reference symbol "x" may represent a cylinder throat between a pore of an erosion sphere and a pore of the sphere.
For example, in some embodiments, the dried cores were evacuated and saturated with 30% KI solution to completely fill the pores with water and measure their permeability K1Assuming the equivalent number of throat cylinders in the microporous region is N1, the permeability error is e. In the ith circulation process, the equivalent number of throat cylinders in the micropore area is N1-i, N1-i throats are randomly connected with each micropore area, K random distribution modes are carried out in total, and the average permeability K of the throat area is calculated2＝(K1+K2+……+Kk) K, if K2-K1|<e, then K is selectediMedium permeability and K1The distribution combination with the minimum absolute value is used as the finally established digital core, if | K2-K1|>e, continue to circulate until | K2-K1|<And e, obtaining a finally established digital core. Wherein, because there are N1 throat pillars that can be set up totally, in the ith cycle, there are N1-i equivalent throat pillars in the micropore region, so link N1-i throats with each micropore region at random, can include
Figure BDA0002360771340000101
A random distribution mode is adopted, wherein
Figure BDA0002360771340000102
The absolute minimum is understood to mean that the absolute value of the difference is minimal. It should be noted that the number of throat connections randomly connected to each microporous region cannot be greater than the maximum number of throat connections for the microporous region.
According to the method for constructing the digital core, the micropore area and the micropore porosity in the core sample are determined according to the CT scanning result, then the digital core is established by utilizing a maximum sphere algorithm and a porosity equivalence method, and finally the established digital core is corrected by utilizing a permeability iteration method, so that the pore throat structure of the real core can be reflected more truly by the established digital core, errors of the digital core and the real core can be reduced, and the construction precision of the digital core is improved.
In the present specification, each embodiment of the method is described in a progressive manner, and the same and similar parts in each embodiment may be joined together, and each embodiment focuses on the differences from the other embodiments. Relevant points can be obtained by referring to part of the description of the embodiment of the method.
Based on the method for constructing the digital core, one or more embodiments of the present specification further provide an apparatus for constructing the digital core. The apparatus may include systems (including distributed systems), software (applications), modules, components, servers, clients, etc. that use the methods described in the embodiments of the present specification in conjunction with any necessary apparatus to implement the hardware. Based on the same innovative conception, embodiments of the present specification provide an apparatus as described in the following embodiments. Since the implementation scheme of the apparatus for solving the problem is similar to that of the method, the specific implementation of the apparatus in the embodiment of the present specification may refer to the implementation of the foregoing method, and repeated details are not repeated. As used hereinafter, the term "unit" or "module" may be a combination of software and/or hardware that implements a predetermined function. Although the means described in the embodiments below are preferably implemented in software, an implementation in hardware, or a combination of software and hardware is also possible and contemplated.
Specifically, fig. 6 is a schematic block diagram of an embodiment of an apparatus for constructing a digital core provided in the present specification, and as shown in fig. 6, the apparatus for constructing a digital core provided in the present specification may include: a micropore area determination module 120, a porosity calculation module 122, a pore network model building module 124, a permeability calculation module 126, and a digital core building module 128.
A micropore area determining module 120, configured to perform CT scanning on the core sample, and determine a micropore area in the core sample based on a CT scanning result;
a porosity calculation module 122 operable to calculate a porosity of micropores in the micropore region;
a pore network model establishing module 124, configured to perform equivalent processing on a pore region and a micropore region included in the CT scanning result based on the porosity, so as to establish a pore network model;
a permeability calculation module 126, configured to calculate a permeability of the pore network model, and determine whether the permeability meets a preset error criterion;
the digital core construction module 128 may be configured to determine that the pore network model is a constructed digital core when it is determined that the permeability meets a preset error criterion.
In another embodiment of the apparatus, the micro-pore region determining module 120 may include:
the first scanning unit 1200 may be configured to perform CT scanning on the core sample to obtain a first scanning result;
the second scanning unit 1202 may be configured to perform CT scanning after performing first processing on the core sample to obtain a second scanning result, where the first processing includes vacuumizing the core sample and injecting a saturated solution;
a micropore area determining unit 1204, configured to compare the first scanning result with the second scanning result, and determine a micropore area in the core sample.
In another embodiment of the apparatus, the porosity calculating module 122 may include:
the CT value calculating unit 1220 may be configured to calculate a CT value of the micropore area according to the following formula based on the first scanning result:
CTgeneral assembly＝∑CTiφi
Wherein, CTGeneral assemblyCT value, CT, representing the micropore areaiRepresents the CT value, phi, of the i substance in the microporous regioniRepresenting the proportion of i substances in the microporous region, wherein the first scanning result comprises a result obtained by performing CT scanning on the core sample;
a porosity calculation unit 1222 for calculating a porosity of the micropores in the micropore area based on the CT value of the micropore area and the second scan result according to the following formula:
CTgeneral assembly＝CTSolutions of×φMicro-pores+CTFramework×(1-φMicro-pores)
Wherein, CTSolutions ofRepresents the CT value, CT, of the solutionFrameworkCT value, phi, representing the skeletonMicro-poresAnd the second scanning result comprises the result obtained by performing CT scanning after the first treatment on the core sample.
In another embodiment of the apparatus, the pore network modeling module 124 may include:
the first equivalent processing unit 1240 may be configured to perform equivalent processing on a pore region included in the CT scanning result by using a maximum sphere algorithm, using a sphere pore and a cylindrical throat, and establishing an initial pore network model;
the second equivalent processing unit 1242 may be configured to perform equivalent processing on the micropore area in the initial pore network model by using a sphere micropore by using a porosity equivalent method;
the pore network model establishing unit 1244 may be configured to connect the sphere micropores and the sphere pores adjacent to the sphere micropores to establish a pore network model.
In another embodiment of the apparatus, the permeability calculation module 126 may include:
the correcting unit 1260 may be configured to, when it is determined that the permeability does not meet a preset error criterion, perform correction processing on the pore network model to obtain a corrected pore network model;
the judging unit 1262 may be configured to calculate a permeability of the corrected pore network model, and judge whether the permeability of the corrected pore network model meets a preset error criterion.
In another embodiment of the apparatus, the correcting the pore network model may include:
and the corrosion unit can be used for carrying out corrosion treatment on the cylinder throat between the sphere micropores and the sphere pores in the pore network model by utilizing a Monte Carlo algorithm.
According to the device for constructing the digital core, the micropore area and the micropore porosity in the core sample are determined according to the CT scanning result, then the digital core is established by utilizing a maximum sphere algorithm and a porosity equivalent method, and finally the established digital core is corrected by utilizing a permeability iteration method, so that the pore throat structure of the real core can be reflected more truly by the established digital core, errors of the digital core and the real core can be reduced, and the construction precision of the digital core is improved.
It should be noted that the above-mentioned description of the apparatus according to the method embodiment may also include other embodiments, and specific implementation manners may refer to the description of the related method embodiment, which is not described herein again.
The present specification also provides embodiments of an apparatus for constructing a digital core, comprising a processor and a memory for storing processor-executable instructions, which when executed by the processor, implement steps comprising:
performing CT scanning on the core sample, and determining a micropore area in the core sample based on the CT scanning result;
calculating the porosity of micropores in the micropore area;
performing equivalent treatment on a pore region and a micropore region included in the CT scanning result based on the porosity, and establishing a pore network model;
calculating the permeability of the pore network model, and judging whether the permeability meets a preset error criterion;
and when the permeability is confirmed to meet a preset error criterion, determining the pore network model as the constructed digital core.
It should be noted that the above description of the apparatus according to the method embodiment may also include other embodiments. The specific implementation manner may refer to the description of the related method embodiment, and is not described in detail herein.
The present specification also provides embodiments of a system for constructing a digital core, comprising at least one processor and a memory storing computer-executable instructions, which when executed by the processor, implement the steps of the method described in any one or more of the above embodiments, for example, comprising: performing CT scanning on the core sample, and determining a micropore area in the core sample based on the CT scanning result; calculating the porosity of micropores in the micropore area; performing equivalent treatment on a pore region and a micropore region included in the CT scanning result based on the porosity, and establishing a pore network model; calculating the permeability of the pore network model, and judging whether the permeability meets a preset error criterion; and when the permeability is confirmed to meet a preset error criterion, determining the pore network model as the constructed digital core. The system may be a single server, or may include a server cluster, a system (including a distributed system), software (applications), an actual operating device, a logic gate device, a quantum computer, etc. using one or more of the methods or one or more of the example devices of the present specification, in combination with a terminal device implementing hardware as necessary.
The method embodiments provided in the present specification may be executed in a mobile terminal, a computer terminal, a server or a similar computing device. Taking an example of the server running on a server, fig. 7 is a hardware structure block diagram of an embodiment of a server for building a digital core provided in this specification, where the server may be an apparatus for building a digital core or a system for building a digital core in the above embodiments. As shown in fig. 7, the server 10 may include one or more (only one shown) processors 100 (the processors 100 may include, but are not limited to, a processing device such as a microprocessor MCU or a programmable logic device FPGA, etc.), a memory 200 for storing data, and a transmission module 300 for communication functions. It will be understood by those skilled in the art that the structure shown in fig. 7 is only an illustration and is not intended to limit the structure of the electronic device. For example, the server 10 may also include more or fewer components than shown in FIG. 7, and may also include other processing hardware, such as a database or multi-level cache, a GPU, or have a different configuration than shown in FIG. 7, for example.
The memory 200 may be used to store software programs and modules of application software, such as program instructions/modules corresponding to the method for constructing the digital core in the embodiments of the present specification, and the processor 100 executes various functional applications and data processing by executing the software programs and modules stored in the memory 200. Memory 200 may include high speed random access memory and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some examples, memory 200 may further include memory located remotely from processor 100, which may be connected to a computer terminal through a network. Examples of such networks include, but are not limited to, the internet, intranets, local area networks, mobile communication networks, and combinations thereof.
The transmission module 300 is used for receiving or transmitting data via a network. Specific examples of the network described above may include a wireless network provided by a communication provider of the computer terminal. In one example, the transmission module 300 includes a Network adapter (NIC) that can be connected to other Network devices through a base station so as to communicate with the internet. In one example, the transmission module 300 may be a Radio Frequency (RF) module, which is used for communicating with the internet in a wireless manner.
The foregoing description has been directed to specific embodiments of this disclosure. Other embodiments are within the scope of the following claims. In some cases, the actions or steps recited in the claims may be performed in a different order than in the embodiments and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In some embodiments, multitasking and parallel processing may also be possible or may be advantageous.
The method or apparatus provided by the present specification and described in the foregoing embodiments may implement service logic through a computer program and record the service logic on a storage medium, where the storage medium may be read and executed by a computer, so as to implement the effect of the solution described in the embodiments of the present specification.
The storage medium may include a physical device for storing information, and typically, the information is digitized and then stored using an electrical, magnetic, or optical media. The storage medium may include: devices that store information using electrical energy, such as various types of memory, e.g., RAM, ROM, etc.; devices that store information using magnetic energy, such as hard disks, floppy disks, tapes, core memories, bubble memories, and usb disks; devices that store information optically, such as CDs or DVDs. Of course, there are other ways of storing media that can be read, such as quantum memory, graphene memory, and so forth.
The embodiments of the method or apparatus for constructing a digital core provided in this specification may be implemented in a computer by a processor executing corresponding program instructions, for example, implemented in a PC end using a c + + language of a windows operating system, implemented in a linux system, or implemented in an intelligent terminal using, for example, android and iOS system programming languages, implemented in processing logic based on a quantum computer, and the like.
It should be noted that descriptions of the apparatus, the computer storage medium, and the system described above according to the related method embodiments may also include other embodiments, and specific implementations may refer to descriptions of corresponding method embodiments, which are not described in detail herein.
The embodiments in the present application are described in a progressive manner, and the same and similar parts among the embodiments can be referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for the hardware + program class embodiment, since it is substantially similar to the method embodiment, the description is simple, and the relevant points can be referred to the partial description of the method embodiment.
The embodiments of this specification are not limited to what must be in compliance with industry communication standards, standard computer data processing and data storage rules, or the description of one or more embodiments of this specification. Certain industry standards, or implementations modified slightly from those described using custom modes or examples, may also achieve the same, equivalent, or similar, or other, contemplated implementations of the above-described examples. The embodiments using the modified or transformed data acquisition, storage, judgment, processing and the like can still fall within the scope of the alternative embodiments of the embodiments in this specification.
In the 90 s of the 20 th century, improvements in a technology could clearly distinguish between improvements in hardware (e.g., improvements in circuit structures such as diodes, transistors, switches, etc.) and improvements in software (improvements in process flow). However, as technology advances, many of today's process flow improvements have been seen as direct improvements in hardware circuit architecture. Designers almost always obtain the corresponding hardware circuit structure by programming an improved method flow into the hardware circuit. Thus, it cannot be said that an improvement in the process flow cannot be realized by hardware physical modules. For example, a Programmable Logic Device (PLD), such as a Field Programmable Gate Array (FPGA), is an integrated circuit whose Logic functions are determined by programming the Device by a user. A digital system is "integrated" on a PLD by the designer's own programming without requiring the chip manufacturer to design and fabricate application-specific integrated circuit chips. Furthermore, nowadays, instead of manually making an Integrated Circuit chip, such Programming is often implemented by "logic compiler" software, which is similar to a software compiler used in program development and writing, but the original code before compiling is also written by a specific Programming Language, which is called Hardware Description Language (HDL), and HDL is not only one but many, such as abel (advanced Boolean Expression Language), ahdl (alternate Hardware Description Language), traffic, pl (core universal Programming Language), HDCal (jhdware Description Language), lang, Lola, HDL, laspam, hardward Description Language (vhr Description Language), vhal (Hardware Description Language), and vhigh-Language, which are currently used in most common. It will also be apparent to those skilled in the art that hardware circuitry that implements the logical method flows can be readily obtained by merely slightly programming the method flows into an integrated circuit using the hardware description languages described above.
The controller may be implemented in any suitable manner, for example, the controller may take the form of, for example, a microprocessor or processor and a computer-readable medium storing 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, and an embedded microcontroller, examples of which include, but are not limited to, the following microcontrollers: ARC 625D, Atmel AT91SAM, Microchip PIC18F26K20, and Silicone Labs C8051F320, the memory controller may also be implemented as part of the control logic for the memory. Those skilled in the art will also appreciate that, in addition to implementing the controller as pure computer readable program code, the same functionality can be implemented by logically programming method steps such that the controller is in the form of logic gates, switches, application specific integrated circuits, programmable logic controllers, embedded microcontrollers and the like. Such a controller may thus be considered a hardware component, and the means included therein for performing the various functions may also be considered as a structure within the hardware component. Or even means for performing the functions may be regarded as being both a software module for performing the method and a structure within a hardware component.
The systems, devices, modules or units illustrated in the above embodiments may be implemented by a computer chip or an entity, or by a product with certain functions. One typical implementation device is a computer. In particular, the computer may be, for example, a personal computer, a laptop computer, a vehicle-mounted human-computer interaction device, a cellular telephone, a camera phone, a smart phone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or a combination of any of these devices.
Although one or more embodiments of the present description provide method operational steps as described in the embodiments or flowcharts, more or fewer operational steps may be included based on conventional or non-inventive approaches. The order of steps recited in the embodiments is merely one manner of performing the steps in a multitude of orders and does not represent the only order of execution. When an actual apparatus or end product executes, it may execute sequentially or in parallel (e.g., parallel processors or multi-threaded environments, or even distributed data processing environments) according to the method shown in the embodiment or the figures. The terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, the presence of additional identical or equivalent elements in a process, method, article, or apparatus that comprises the recited elements is not excluded. The terms first, second, etc. are used to denote names, but not any particular order.
For convenience of description, the above devices are described as being divided into various modules by functions, and are described separately. Of course, when implementing one or more of the present description, the functions of each module may be implemented in one or more software and/or hardware, or a module implementing the same function may be implemented by a combination of multiple sub-modules or sub-units, etc. The above-described embodiments of the apparatus are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.
The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), 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.
In a typical configuration, a computing device includes one or more processors (CPUs), input/output interfaces, network interfaces, and memory.
The memory may include forms of volatile memory in a computer readable medium, Random Access Memory (RAM) and/or non-volatile memory, such as Read Only Memory (ROM) or flash memory (flash RAM). Memory is an example of a computer-readable medium.
Computer-readable media, including both non-transitory and non-transitory, removable and non-removable media, may implement information storage by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), Read Only Memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), Digital Versatile Discs (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage, graphene storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information that can be accessed by a computing device. As defined herein, a computer readable medium does not include a transitory computer readable medium such as a modulated data signal and a carrier wave.
As will be appreciated by one skilled in the art, one or more embodiments of the present description may be provided as a method, system, or computer program product. Accordingly, one or more embodiments of the present description may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, one or more embodiments of the present description may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for the system embodiment, since it is substantially similar to the method embodiment, the description is simple, and for the relevant points, reference may be made to the partial description of the method embodiment. In the description of the specification, reference to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the specification. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
The above description is merely exemplary of one or more embodiments of the present disclosure and is not intended to limit the scope of one or more embodiments of the present disclosure. Various modifications and alterations to one or more embodiments described herein will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims.

Claims (9)

1. A method of constructing a digital core, comprising:
performing CT scanning on the core sample, and determining a micropore area in the core sample based on the CT scanning result; wherein, the CT scanning is carried out on the core sample, and the micropore area in the core sample is determined based on the CT scanning result, and the method comprises the following steps: carrying out CT scanning on the rock core sample to obtain a first scanning result; performing CT scanning after performing first treatment on the core sample to obtain a second scanning result, wherein the first treatment comprises vacuumizing the core sample and injecting a saturated solution; comparing the first scanning result with the second scanning result to determine a micropore area in the rock core sample;
calculating the porosity of micropores in the micropore area; wherein the calculating the porosity of the micropores in the micropore region comprises: calculating a CT value of the micropore area based on the first scanning result; calculating the porosity of micropores in the micropore area based on the CT value of the micropore area and the second scanning result;
performing equivalent treatment on a pore region and a micropore region included in the CT scanning result based on the porosity, and establishing a pore network model; performing equivalent processing on a pore region and a micropore region included in the CT scanning result based on the porosity, and establishing a pore network model, wherein the equivalent processing comprises the following steps: performing equivalent treatment on a pore region included in the CT scanning result by using a spherical pore and a columnar throat by using a maximum sphere algorithm, and establishing an initial pore network model; performing equivalent treatment on the micropore area in the initial pore network model by using spherical micropores by using a porosity equivalent method; connecting the sphere micropores with sphere pores adjacent to the sphere micropores to establish a pore network model;
calculating the permeability of the pore network model, and judging whether the permeability meets a preset error criterion;
and when the permeability is confirmed to meet a preset error criterion, determining the pore network model as the constructed digital core.
2. The method of claim 1, wherein the calculating the porosity of the micropores in the micropore region comprises:
calculating the CT value of the micropore area based on the first scanning result according to the following formula:
CTgeneral assembly＝∑CTiφi
Wherein, CTGeneral assemblyCT value, CT, representing the micropore areaiRepresents the CT value, phi, of the i substance in the microporous regioniRepresenting the proportion of i substances in the microporous region, wherein the first scanning result comprises a result obtained by performing CT scanning on the core sample;
calculating the porosity of the micropores in the micropore region according to the following formula based on the CT value of the micropore region and the second scanning result:
CTgeneral assembly＝CTSolutions of×φMicro-pores+CTFramework×(1-φMicro-pores)
Wherein, CTSolutions ofRepresents the CT value, CT, of the solutionFrameworkCT value, phi, representing the skeletonMicro-poresAnd the second scanning result comprises the result obtained by performing CT scanning after the first treatment on the core sample.
3. The method of claim 1, wherein the calculating the permeability of the pore network model and determining whether the permeability meets a predetermined error criterion comprises:
when the permeability is confirmed to not meet a preset error criterion, correcting the pore network model to obtain a corrected pore network model;
and calculating the permeability of the corrected pore network model, and judging whether the permeability of the corrected pore network model meets a preset error criterion.
4. The method of claim 3, wherein said applying a correction to said pore network model comprises:
and corroding the cylinder throat between the sphere micropores and the sphere pores in the pore network model by using a Monte Carlo algorithm.
5. An apparatus for constructing a digital core, comprising:
the micropore area determining module is used for carrying out CT scanning on the core sample and determining the micropore area in the core sample based on the CT scanning result; wherein the micropore area determining module comprises: the first scanning unit is used for carrying out CT scanning on the rock core sample to obtain a first scanning result; the second scanning unit is used for performing CT scanning after the first treatment is performed on the core sample to obtain a second scanning result, wherein the first treatment comprises the steps of vacuumizing the core sample and injecting a saturated solution; a micropore area determining unit, configured to compare the first scanning result with the second scanning result, and determine a micropore area in the core sample;
a porosity calculation module for calculating the porosity of the micropores in the micropore area; wherein the calculating the porosity of the micropores in the micropore region comprises: calculating a CT value of the micropore area based on the first scanning result; calculating the porosity of micropores in the micropore area based on the CT value of the micropore area and the second scanning result;
the pore network model establishing module is used for performing equivalent treatment on a pore region and a micropore region included in the CT scanning result based on the porosity to establish a pore network model; wherein the pore network model building module comprises: the first equivalent processing unit is used for carrying out equivalent processing on a pore region included in the CT scanning result by using a spherical pore and a columnar throat by using a maximum sphere algorithm to establish an initial pore network model; the second equivalent processing unit is used for carrying out equivalent processing on the micropore area in the initial pore network model by using a sphere micropore by using a porosity equivalent method; the pore network model establishing unit is used for connecting the sphere micropores and sphere pores adjacent to the sphere micropores to establish a pore network model;
the permeability calculation module is used for calculating the permeability of the pore network model and judging whether the permeability meets a preset error criterion;
and the digital core construction module is used for determining the pore network model as the constructed digital core when the permeability is confirmed to meet the preset error criterion.
6. The apparatus of claim 5, wherein the porosity calculation module comprises:
a CT value calculating unit for calculating the CT value of the micropore area according to the following formula based on the first scanning result:
CTgeneral assembly＝∑CTiφi
Wherein, CTGeneral assemblyCT value, CT, representing the micropore areaiRepresents the CT value, phi, of the i substance in the microporous regioniRepresenting the proportion of i substances in the microporous region, wherein the first scanning result comprises a result obtained by performing CT scanning on the core sample;
a porosity calculation unit for calculating the porosity of the micropores in the micropore area according to the following formula based on the CT value of the micropore area and the second scanning result:
CTgeneral assembly＝CTSolutions of×φMicro-pores+CTFramework×(1-φMicro-pores)
Wherein, CTSolutions ofRepresents the CT value, CT, of the solutionFrameworkCT value, phi, representing the skeletonMicro-poresAnd the second scanning result comprises the result obtained by performing CT scanning after the first treatment on the core sample.
7. The apparatus of claim 5, wherein the permeability calculation module comprises:
the correcting unit is used for correcting the pore network model when the permeability is confirmed not to meet the preset error criterion, and obtaining the corrected pore network model;
and the judging unit is used for calculating the permeability of the corrected pore network model and judging whether the permeability of the corrected pore network model meets a preset error criterion.
8. The apparatus of claim 7, wherein said correction processing of said pore network model comprises:
and the corrosion unit is used for carrying out corrosion treatment on the cylinder throat between the sphere micropores and the sphere pores in the pore network model by utilizing a Monte Carlo algorithm.
9. A system for constructing a digital core, comprising at least one processor and a memory storing computer-executable instructions that, when executed by the processor, implement the steps of the method of any one of claims 1-4.
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