CN115685345A

CN115685345A - Fracture reservoir determining method and device, storage medium and electronic equipment

Info

Publication number: CN115685345A
Application number: CN202110852072.9A
Authority: CN
Inventors: 马玉春; 黄继文; 储呈林; 张永东
Original assignee: China Petroleum and Chemical Corp; Sinopec Exploration and Production Research Institute
Current assignee: China Petroleum and Chemical Corp; Sinopec Exploration and Production Research Institute
Priority date: 2021-07-27
Filing date: 2021-07-27
Publication date: 2023-02-03

Abstract

The method comprises the steps of firstly establishing an initial low-frequency model according to seismic data and well logging data of a target area, meanwhile establishing a fracture impedance model according to the seismic data, and then obtaining a mixed impedance low-frequency model according to the initial low-frequency model and the fracture impedance model, so that the reservoir distribution can be carved on a longitudinal and transverse three-dimensional space according to the mixed impedance low-frequency model. And (3) inverting the mixed impedance low-frequency model to obtain a longitudinal wave impedance data volume of the target area, wherein the longitudinal wave impedance data volume can reflect information such as lithology and physical properties of the target area. Therefore, the spatial distribution of the fracture-cavity body in the target area can be accurately depicted according to the longitudinal wave impedance data volume and the relation function of the relation between the longitudinal wave impedance data volume and the porosity, so that the fracture-cavity communication relation of the reservoir can be more intuitively depicted.

Description

Fracture reservoir determining method and device, storage medium and electronic equipment

Technical Field

The application relates to the technical field of oil and gas exploration, in particular to a method and a device for determining a fractured reservoir, a storage medium and electronic equipment.

Background

The fractures are the smallest, most widely distributed, and most complex structures on the earth's surface. The fractures can be used as good reservoir space and fluid migration channels in oil and gas exploration, and have important influence on the connectivity, the capacity and the reserve of the reservoir. In recent years, a plurality of methods and technologies are formed for identification and description of fractured reservoirs, including post-stack attribute technologies such as edge detection, eigenvalues, curvatures, ant bodies and the like, and pre-stack technologies such as azimuth anisotropic inversion and the like, but because fracture cause types are complex, various prediction methods and description parameters for fractures are also emphasized, so that no matter the post-stack attribute calculation or the pre-stack anisotropic inversion is performed, a single prediction method can only predict a certain fracture-fracture or fracture development zone, and the prediction result is the comprehensive response of fractured reservoirs with different levels and different scales. The technique for forming the descriptive crack by using the post-stack seismic data is to qualitatively describe the geometrical characteristics of the crack. The azimuth and the density of the fracture can be finally described by utilizing a prestack azimuth anisotropic inversion method, but the transverse characteristic of the reservoir can only be described by utilizing the post-stack seismic data and adopting the conventional inversion technology, and the longitudinal characteristic similar to the fracture type reservoir cannot be described.

Disclosure of Invention

In order to solve the problems, the application provides a fracture reservoir determination method, a fracture reservoir determination device, a storage medium and electronic equipment.

In a first aspect, the present application provides a method for fracture reservoir determination, the method comprising:

establishing an initial low-frequency model according to the acquired seismic data and the acquired logging data of the target area;

establishing a fracture impedance model according to the seismic data;

obtaining a mixed impedance low-frequency model according to the initial low-frequency model and the crack impedance model;

performing inversion according to the mixed impedance low-frequency model, determining a longitudinal wave impedance data volume of the target area, and determining the spatial distribution of the target area based on the longitudinal wave impedance data volume;

and acquiring a relation function representing the relation between the longitudinal wave impedance data body and the porosity, and determining the fracture reservoir based on the spatial distribution according to the relation function.

In the above embodiment, the initial low-frequency model is established according to the seismic data and the well logging data of the target area, the fracture impedance model is established according to the seismic data, and then the mixed impedance low-frequency model is obtained according to the initial low-frequency model and the fracture impedance model, so that the spatial distribution of the target area can be described in the longitudinal and transverse three-dimensional space according to the mixed impedance low-frequency model. And inverting the mixed impedance low-frequency model to obtain a longitudinal wave impedance data volume of the target area, wherein the longitudinal wave impedance data volume can reflect information such as lithology, physical property and the like of the target area. Therefore, the spatial distribution of the fracture-cavity body in the target area can be accurately depicted according to the longitudinal wave impedance data body and the relation function of the relationship between the longitudinal wave impedance data body and the porosity, so that the fracture-cavity communication relationship of the reservoir can be more visually depicted.

According to an embodiment of the present application, optionally, in the method for determining a fracture reservoir, the establishing an initial low-frequency model from the acquired seismic data and the acquired well log data in the target region includes:

carrying out well-seismic calibration building time-depth relation based on the acquired well logging data and the seismic data;

establishing a frame model of the clastic rock stratum in the target area according to the time-depth relation;

determining longitudinal wave impedance data and background longitudinal wave impedance data of the depth direction of the target area according to the logging information;

performing transverse interpolation on the frame model by using the longitudinal wave impedance data to obtain a low-frequency impedance model of the clastic rock stratum;

determining a background low-frequency longitudinal wave impedance model of the carbonate stratum in the target area based on the background longitudinal wave impedance value;

and determining an initial low-frequency model based on the low-frequency impedance model and the background low-frequency longitudinal wave impedance model.

According to an embodiment of the application, optionally, in the method for determining a fractured reservoir, the well logging information includes: acoustic data and density data for a single well, the seismic data comprising: seismic wavelet data, said well-seismic calibration build-time-depth relationship based on said acquired logging data and said seismic data, comprising:

determining a reflection coefficient based on the acoustic data and the density data for the single well;

convolution is carried out on the reflection coefficient and the seismic wavelets to obtain a synthetic seismic record;

the time-depth relationship is established based on the synthetic seismic record.

According to an embodiment of the present application, optionally, in the method for determining a fracture reservoir, establishing a fracture impedance model according to the seismic data includes:

performing structure-oriented filtering processing on the seismic data to obtain filtered seismic data;

carrying out fault automatic detection (AFE) calculation on the basis of the filtered seismic data to obtain a middle fracture impedance model of the target area; the intermediate fracture impedance model includes AFE values;

and acquiring an AFE threshold corresponding to the target area, and determining the fracture impedance model based on the AFE threshold and an AFE value in the intermediate fracture impedance model.

According to an embodiment of the present application, optionally, in the method for determining a fracture reservoir, determining the fracture impedance model based on the AFE threshold and the AFE value in the intermediate fracture impedance model includes:

acquiring a constant impedance value corresponding to the target area;

and determining the AFE value which is larger than the AFE threshold value in the intermediate fracture impedance model as the constant impedance value, and determining the AFE value which is smaller than the AFE threshold value in the intermediate fracture impedance model as a null value to obtain the fracture impedance model.

According to an embodiment of the present application, optionally, in the above method for determining a fracture reservoir, performing inversion according to the mixed impedance low-frequency model, and determining a compressional impedance data volume of the target region, so as to determine a spatial distribution of the target region based on the compressional impedance data volume includes:

performing constrained sparse pulse inversion by adopting the mixed impedance low-frequency model based on the seismic data to obtain longitudinal wave impedance data of the target area;

determining target longitudinal wave impedance data based on the longitudinal wave impedance data and a longitudinal wave impedance threshold;

and determining the space position corresponding to the target longitudinal wave impedance data as the space distribution of the target area.

According to an embodiment of the present application, optionally, in the method for determining a fractured reservoir, obtaining a relationship function representing a relationship between a longitudinal wave impedance data volume and porosity, so as to determine the fractured reservoir based on the spatial distribution according to the relationship function, includes:

calculating the porosity of the target area according to the relation function and the longitudinal wave impedance data volume of the target area;

determining the fractured reservoir according to the porosity.

In a second aspect, the present application provides a fracture reservoir determination apparatus, the apparatus comprising:

the initial low-frequency model establishing module is used for establishing an initial low-frequency model according to the acquired seismic data and the acquired logging data of the target area;

the crack impedance model establishing module is used for establishing a crack impedance model according to the seismic data;

the mixed impedance low-frequency model determining module is used for obtaining a mixed impedance low-frequency model according to the initial low-frequency model and the crack impedance model;

a longitudinal wave impedance data volume determining module, configured to perform inversion according to the mixed impedance low-frequency model, determine a longitudinal wave impedance data volume of the target area, and determine a spatial distribution of the target area based on the longitudinal wave impedance data volume;

and the fracture determining module is used for acquiring a relation function representing the relation between the longitudinal wave impedance data body and the porosity, and determining the fracture reservoir based on the spatial distribution according to the relation function.

According to an embodiment of the application, optionally, in the above fracture reservoir determining apparatus, the initial low-frequency model building module includes:

the well-seismic calibration unit is used for carrying out well-seismic calibration building time-depth relation based on the acquired well logging data and the seismic data;

the frame model establishing unit is used for establishing a frame model of the clastic rock stratum in the target area according to the time-depth relation;

the impedance data determining unit is used for determining longitudinal wave impedance data and background longitudinal wave impedance data of the depth direction of the target area according to the logging information;

the low-frequency impedance model obtaining unit is used for performing transverse interpolation on the frame model by using the longitudinal wave impedance data to obtain a low-frequency impedance model of the clastic rock stratum;

the background low-frequency longitudinal wave impedance model determining unit is used for determining a background low-frequency longitudinal wave impedance model of the carbonate stratum in the target area based on the background longitudinal wave impedance value;

and the initial low-frequency model determining unit is used for determining an initial low-frequency model based on the low-frequency impedance model and the background low-frequency longitudinal wave impedance model.

According to an embodiment of the application, optionally, in the above fracture reservoir determining apparatus, the well log data includes: acoustic and density data for a single well, the seismic data including: seismic wavelet data, the well-seismic calibration unit comprising:

a reflection coefficient determining subunit for determining a reflection coefficient based on the acoustic data and the density data of the single well;

the synthetic seismic record obtaining subunit is used for performing convolution on the reflection coefficient and the seismic wavelets to obtain a synthetic seismic record;

a time-depth relationship establishing subunit for establishing the time-depth relationship based on the synthetic seismic record.

According to an embodiment of the present application, optionally, in the above fracture reservoir determining apparatus, the fracture impedance model establishing module includes:

the structure-oriented filtering unit is used for performing structure-oriented filtering processing on the seismic data to obtain filtered seismic data;

the fault automatic detection unit is used for carrying out fault automatic detection (AFE) calculation on the basis of the filtered seismic data to obtain a middle fracture impedance model of the target area; the intermediate fracture impedance model includes AFE values;

and the fracture impedance model determining unit is used for acquiring an AFE threshold corresponding to the target area and determining the fracture impedance model based on the AFE threshold and an AFE value in the intermediate fracture impedance model.

According to an embodiment of the application, optionally, in the above fracture reservoir determining apparatus, the fracture impedance model determining unit includes:

the constant impedance value acquisition subunit is used for acquiring a constant impedance value corresponding to the target area;

and the fracture impedance model subunit is used for determining an AFE value which is greater than the AFE threshold value in the intermediate fracture impedance model as the constant impedance value, and determining an AFE value which is less than the AFE threshold value in the intermediate fracture impedance model as a null value so as to obtain the fracture impedance model.

According to an embodiment of the present application, optionally, in the above fracture reservoir determining apparatus, the longitudinal wave impedance data volume determining module includes:

the longitudinal wave impedance data acquisition unit is used for performing constraint sparse pulse inversion by adopting the mixed impedance low-frequency model based on the seismic data to obtain longitudinal wave impedance data of the target area;

a target longitudinal wave impedance data determination unit for determining target longitudinal wave impedance data based on the longitudinal wave impedance data and a longitudinal wave impedance threshold;

and the space determining unit is used for determining the space position corresponding to the target longitudinal wave impedance data as the space spread of the target area.

According to an embodiment of the application, optionally, in the above fractured reservoir determination apparatus, the fracture determination module includes:

the porosity calculation unit is used for calculating the porosity of the target area according to the relation function and the longitudinal wave impedance data volume of the target area;

and the fracture determining unit is used for determining the fracture reservoir according to the porosity.

In a third aspect, the present application provides a storage medium storing a computer program executable by one or more processors for implementing a method for fracture reservoir determination as described above.

In a fourth aspect, the present application provides an electronic device comprising a memory and a processor, the memory having stored thereon a computer program which, when executed by the processor, performs the above-described fracture reservoir determination method.

In summary, the method, the apparatus, the storage medium, and the electronic device for determining a fractured reservoir provided by the present application include: establishing an initial low-frequency model according to the acquired seismic data and the acquired logging data of the target area; establishing a fracture impedance model according to the seismic data; obtaining a mixed impedance low-frequency model according to the initial low-frequency model and the crack impedance model; performing inversion according to the mixed impedance low-frequency model, determining a longitudinal wave impedance data volume of the target area, and determining the spatial distribution of the target area based on the longitudinal wave impedance data volume; and acquiring a relation function representing the relation between the longitudinal wave impedance data volume and the porosity, and determining the fracture reservoir based on the spatial distribution according to the relation function. The method comprises the steps of establishing an initial low-frequency model according to seismic data and well logging data of a target area, establishing a fracture impedance model according to the seismic data, and then obtaining a mixed impedance low-frequency model according to the initial low-frequency model and the fracture impedance model, so that reservoir spreading can be described in longitudinal and transverse three-dimensional space according to the mixed impedance low-frequency model. And inverting the mixed impedance low-frequency model to obtain a longitudinal wave impedance data volume of the target area, wherein the longitudinal wave impedance data volume can reflect information such as lithology, physical property and the like of the target area. Therefore, the spatial distribution of the fracture-cavity body in the target area can be accurately depicted according to the longitudinal wave impedance data body and the relation function of the relationship between the longitudinal wave impedance data body and the porosity, so that the fracture-cavity communication relationship of the reservoir can be more visually depicted. Furthermore, the resource scale of oil and gas can be accurately calculated, reliable basis is provided for well position deployment, the success rate of exploration, development and well drilling can be improved, the exploration and development benefits are improved, and the method is not limited by regions and has wide application range.

Drawings

The present application will be described in more detail hereinafter on the basis of embodiments and with reference to the accompanying drawings.

Fig. 1 is a schematic flow chart of a fracture reservoir determination method according to an embodiment of the present disclosure.

Fig. 2 is a block diagram of a fractured reservoir determination apparatus according to a fourth embodiment of the present disclosure.

Fig. 3 is a connection block diagram of an electronic device according to a sixth embodiment of the present application.

In the drawings, like parts are designated with like reference numerals, and the drawings are not drawn to scale.

Detailed Description

The following detailed description will be provided with reference to the accompanying drawings and embodiments, so that how to apply the technical means to solve the technical problems and achieve the corresponding technical effects can be fully understood and implemented. The embodiments and various features in the embodiments of the present application can be combined with each other without conflict, and the formed technical solutions are all within the scope of protection of the present application.

Example one

The invention provides a method for determining a fractured reservoir, which is shown in figure 1 and comprises the following steps:

step S110: and establishing an initial low-frequency model according to the acquired seismic data and the acquired logging data of the target area.

An initial low frequency model that substantially reflects the geologic features of the depositional body may be established based on the seismic data and the well log data. The low-frequency model can be obtained by interpolating and extrapolating the logging data in the whole data volume range by taking the seismic data interpretation horizon and the deposition rule as constraints, and in addition, the seismic velocity spectrum information in the seismic data can be combined with the logging data to establish an initial low-frequency model, so that the missing low-frequency information in the seismic data can be compensated to a certain extent. When an initial low-frequency model is established according to seismic data and logging data, a well curve with better quality in the logging data can be selected, and interpolation is carried out according to a certain algorithm under the constraints of horizons, faults and the like, such as a weight method, kriging, reverse distance weighting and the like. In addition to the low-frequency model established by means of seismic velocity conversion, a single well interpolation can be used for establishing an initial low-frequency model, pseudo wells are added to places with larger differences by comparing forward modeling with synthetic records and the original earthquake, the information of the low-frequency model is changed, and a relatively real low-frequency model is obtained by continuously updating. In order to take seismic reflection characteristics into consideration, boundaries of different lithologies and fluids can be defined through attributes such as seismic amplitude and frequency, and different elastic properties can be defined for each phase zone to obtain an initial low-frequency model.

Step S120: and establishing a fracture impedance model according to the seismic data.

The tectonic deformation is one of the main reasons for the formation of the fractured reservoir, the tectonic deformation and the fractures have homology, the tectonic deformation has great influence on the spatial distribution characteristics of the fractures, and the fractures are an important expression form of the tectonic deformation. The fracture is regarded as small in the exploration stage, but the fracture has large influence on the development of the oil field, and the fracture can improve the permeability of a reservoir and can be used as a hydrocarbon reservoir. The geometric characteristics of the seismic data are important attributes for effectively describing the fracture reservoir, and the geometric seismic attributes of the common seismic data comprise the coherence attributes, curvature, dip angle, azimuth angle and the like of the seismic data, so that the geometric seismic attributes can be mainly based on the seismic attributes when a fracture impedance model is established according to the seismic data. Specifically, geometric seismic attribute data required in seismic data are determined, then eigenvalue coherent body manufacturing is performed, automatic Fault Extraction (AFE) is performed on the basis of coherent bodies, and then a gap impedance model is established according to the automatic fault extraction calculation result.

Step S130: and obtaining a mixed impedance low-frequency model according to the initial low-frequency model and the crack impedance model.

Specifically, the low-frequency model may be used to replace a corresponding null value in the fracture impedance model, so as to obtain a mixed impedance low-frequency model. The null part in the crack impedance model is replaced by the value corresponding to the initial low-frequency model in step S110, so as to obtain the mixed impedance low-frequency model.

According to the initial low-frequency model, the transverse characteristics of the target area can be described, the longitudinal geometrical characteristics of the crack can be qualitatively described by using the crack impedance model, and the spatial distribution of the target area can be described in the longitudinal and transverse three-dimensional space by using the mixed impedance low-frequency model obtained according to the initial low-frequency model and the crack impedance model.

Step S140: and performing inversion according to the mixed impedance low-frequency model, determining a longitudinal wave impedance data volume of the target area, and determining the spatial distribution of the target area based on the longitudinal wave impedance data volume.

According to an embodiment of the present application, step S140 includes the steps of:

step S141: and performing constrained sparse pulse inversion by adopting the mixed impedance low-frequency model based on the seismic data to obtain longitudinal wave impedance data of the target area.

The inversion of the mixed impedance low-frequency model according to the seismic data can fully utilize the information such as structure, horizon, lithology and the like provided by the seismic data and the logging data to convert the change of the conventional seismic reflection amplitude into the longitudinal wave impedance data of the target area so as to reflect the information such as lithology, physical property and the like of the target area. The longitudinal wave impedance data of the target area can accurately analyze the mineral composition and porosity of the bedrock. During the exposure period, the strength of the matrix from shallow to deep weathered leaching is weaker and weaker, the porosity is smaller and smaller, the longitudinal wave impedance is larger and larger, when the matrix is not weathered and leached by surface water at all, the porosity is close to zero, and the longitudinal wave impedance value is maximum and only related to mineral components forming the rock.

Specifically, the seismic data may be processed in detail to extract parameters such as seismic volume and seismic wavelet, and then the constrained sparse impulse inversion may be performed on the initial low-frequency model. The constraint sparse impulse inversion is a recursion seismic wave impedance inversion method, the constraint sparse impulse inversion widens the effective frequency bandwidth of input seismic data by adjusting the sparsity of a reflection coefficient sequence, an elastic parameter model and a sparsity constraint factor are obtained, a seismic signal-to-noise ratio, a merging frequency and a wavelet scale factor are key parameters in the algorithm, the seismic signal-to-noise ratio is used for constraining the similarity of an inversion result and the seismic data, the higher the signal-to-noise ratio is set, the more relevant a synthetic record converted from the inversion result is to the earthquake, and vice versa, the sparsity constraint factor is the sparsity of the reflection coefficient sequence, and the smaller the value of the sparsity constraint factor is, the more sparse the reflection coefficient sequence is.

Step S142: and determining target longitudinal wave impedance data based on the longitudinal wave impedance data and a longitudinal wave impedance threshold.

After an inversion result is obtained through constraint sparse pulse inversion, a longitudinal wave impedance threshold value can be obtained, when the longitudinal wave impedance threshold value is obtained, a longitudinal wave impedance value corresponding to the position of a beaded reflection corresponding cavern layer reservoir on a longitudinal wave impedance profile obtained through inversion can be determined through well seismic calibration according to a practically drilled cavern layer reservoir, and the longitudinal wave impedance threshold value of the cavern layer reservoir is determined by combining with a practical drilling well to obtain the longitudinal wave impedance value corresponding to the cavern layer reservoir. And then determining target longitudinal wave impedance data from the longitudinal wave impedance data according to the longitudinal wave impedance data and a longitudinal wave impedance threshold value.

Specifically, in determining the target longitudinal wave impedance data, the determination may be made based on the following procedure. Firstly, comparing the longitudinal wave impedance data with the longitudinal wave impedance threshold value; and then determining the part of the longitudinal wave impedance data which is smaller than the longitudinal wave impedance threshold value as target longitudinal wave impedance data. For example, in a carbonate formation, a longitudinal wave impedance data less than this longitudinal wave impedance threshold is determined as the target longitudinal wave impedance data for the cavernous formation reservoir. And carrying out constraint sparse pulse inversion on the target low-frequency model according to the longitudinal wave impedance threshold value to obtain the longitudinal wave impedance data of the target area for depicting. And reserving the longitudinal wave impedance data which is smaller than the longitudinal wave impedance threshold value and determining the longitudinal wave impedance data as target longitudinal wave impedance data, and discarding the longitudinal wave impedance data which is larger than the longitudinal wave impedance threshold value, so that the space of the target area can be drawn according to the reserved target longitudinal wave impedance data.

Step S143: and determining the space position corresponding to the target longitudinal wave impedance data as the space distribution of the target area.

After the target longitudinal wave impedance data are obtained, the obtained full-band target longitudinal wave impedance body can be used for accurately describing the cave reservoir.

Step S150: and acquiring a relation function representing the relation between the longitudinal wave impedance data volume and the porosity, and determining the fracture reservoir based on the spatial distribution according to the relation function.

The longitudinal wave impedance data body is in relation with the porosity, so that a corresponding functional relation between the longitudinal wave impedance data body and the porosity in the actual drilling acquired data can be established in advance, and the pore distribution of the target area on the space can be calculated according to the target longitudinal wave impedance data and the functional relation, so that the determination of the fractured reservoir in the target area is realized.

Specifically, when a relationship function representing a relationship between a longitudinal wave impedance data volume and a porosity is obtained to determine the fracture reservoir based on the spatial distribution according to the relationship function, the porosity of the target region may be calculated according to the relationship function and the longitudinal wave impedance data volume of the target region; the fractured reservoir is then determined from the porosity.

In summary, the present application provides a method for determining a fractured reservoir, comprising: establishing an initial low-frequency model according to the acquired seismic data and the acquired logging data of the target area; establishing a fracture impedance model according to the seismic data; obtaining a mixed impedance low-frequency model according to the initial low-frequency model and the crack impedance model; performing inversion according to the mixed impedance low-frequency model, determining a longitudinal wave impedance data volume of the target area, and determining the spatial distribution of the target area based on the longitudinal wave impedance data volume; and acquiring a relation function representing the relation between the longitudinal wave impedance data volume and the porosity, and determining the fracture reservoir based on the spatial distribution according to the relation function. The method comprises the steps of establishing an initial low-frequency model according to seismic data and well logging data of a target area, establishing a fracture impedance model according to the seismic data, and then obtaining a mixed impedance low-frequency model according to the initial low-frequency model and the fracture impedance model, so that reservoir spreading can be described in longitudinal and transverse three-dimensional spaces according to the mixed impedance low-frequency model. And (3) inverting the mixed impedance low-frequency model to obtain a longitudinal wave impedance data volume of the target area, wherein the longitudinal wave impedance data volume can reflect information such as lithology and physical properties of the target area. Therefore, the spatial distribution of the fracture-cavity body in the target area can be accurately depicted according to the longitudinal wave impedance data volume and the relation function of the relation between the longitudinal wave impedance data volume and the porosity, so that the fracture-cavity communication relation of the reservoir can be visually depicted.

Example two

On the basis of the first embodiment, the present embodiment explains the method in the first embodiment through a specific implementation case.

The method for determining the fractured reservoir comprises the following steps:

In the method for determining a fractured reservoir, the step S110 includes the following steps:

step S1110: and carrying out well-seismic calibration building time-depth relation based on the acquired well logging data and the acquired seismic data.

The structure of the target area can be explained by utilizing seismic data and well logging data, and the reservoir stratum can be predicted, so that the oil reservoir can be described finely. However, the longitudinal scale described by the logging data is depth, the section described by the seismic data is time scale, and the two data description modes are different, so that the two data description modes cannot be directly combined and applied, and the well-seismic calibration between the logging data and the seismic data needs to be carried out firstly. In performing well seismic calibration, calibration may be based on correlation of synthetic seismic records in the seismic data with the borehole-side seismic trace waveforms. In addition, the reflection coefficient can be calculated through acoustic wave and density logging data, a synthetic seismic record similar to a seismic channel is constructed by utilizing the convolution of the emission coefficient and the wavelet, and the calibration result is adjusted by comparing the synthetic seismic record with the seismic channel beside the well to realize well seismic calibration. For example, a sample well of the target area is determined, a single crystal depth domain synthetic seismic record is obtained according to the sample well, and then the corresponding relation between time and depth at the single well is established according to the single well depth domain synthetic seismic record. And finally, automatically matching the residual drilling horizon of the research area to the time domain geological horizon model, thereby realizing the rapid well seismic calibration work of all drilling wells.

Step S1120: and establishing a frame model of the clastic rock stratum in the target area according to the time-depth relation.

The time-depth relation obtained by well seismic calibration can correspond different geological interfaces of single well analysis to a seismic profile, namely from a depth domain to a time domain, so that the different geological interfaces can be tracked spatially by using seismic data to obtain the spatial distribution of the geological interfaces, and a frame model of the clastic rock stratum is established by using the different geological interfaces.

Step S1130: determining longitudinal wave impedance data and background longitudinal wave impedance data of the depth direction of the target area according to the logging information;

step S1140: performing transverse interpolation on the frame model by using the longitudinal wave impedance data to obtain a low-frequency impedance model of the clastic rock stratum;

step S1150: determining a background low-frequency longitudinal wave impedance model of the carbonate stratum in the target area based on the background longitudinal wave impedance value;

step S1160: and determining an initial low-frequency model based on the low-frequency impedance model and the background low-frequency longitudinal wave impedance model.

And under the constraint of the frame model, transversely interpolating longitudinal wave impedance values in different single well longitudinal directions to obtain a well-interpolated low-frequency impedance model. Because the carbonate rock is strong in transverse heterogeneity, the model of single-well transverse interpolation cannot reflect the transverse distribution characteristics of the carbonate rock stratum. Thus, a downhole low frequency model may be used for clastic formations above the carbonate ceiling (T74 seismic reflection interface); and the lower T74 is a carbonate stratum, and the low-frequency model is replaced by the background longitudinal wave impedance value of the carbonate stratum, namely the low-frequency model of the part of the carbonate stratum is a constant straight-plate low-frequency model. Wherein, the background longitudinal wave impedance value can represent the carbonate background value by a constant. Through the method, the abnormal value in the seismic data in the carbonate stratum can reflect the change of the reservoir, the false image caused by the abnormal low-frequency model of well interpolation is eliminated, and the actual underground condition is really reflected.

In the method for determining a fractured reservoir, the well logging information includes: acoustic data and density data for a single well, the seismic data comprising: seismic wavelet data, said step S1110 comprising the steps of:

step S1111: the reflection coefficient is determined based on the acoustic data and the density data for the single well.

After the time domain wavelet is converted into the depth domain, due to the influence of speed, the waveform is compressed or stretched along with the depth, and therefore, the reflection coefficient can be calculated based on the acoustic wave data and the density data. When the reflection coefficient is calculated, the dominant frequency of the wavelet is calculated by selecting a well-side seismic channel with good quality on a depth migration section, the zero-phase wavelet is selected, and the acoustic wave time difference curve and the density curve are corrected, subjected to field value removal and the like before the reflection coefficient is calculated.

Step S1112: and performing convolution on the reflection coefficient and the seismic wavelets to obtain a synthetic seismic record.

Convolution, also known as convolution, is a mathematical method of integral transformation, and is a mathematical operator for generating a third function by two functions, and represents the integral of the product of function values of the overlapped part of the two functions after turning and shifting to the overlapping length. The synthetic seismic records obtained by convolution are seismic records, i.e., seismic traces, that have been artificially synthesized and converted using acoustic logging or vertical seismic profile data. The method is a very wide application in the seismic model technology, is also the basis of the work such as horizon calibration, oil reservoir description and the like, and is an intermediate medium for converting a geological model into seismic information. Synthetic seismic records are bridges combining high-resolution logging information with regional seismic information, and the accuracy of the synthetic seismic records directly affects the accurate calibration of geological horizons.

Step S1113: the time-depth relationship is established based on the synthetic seismic record.

The well data is in the depth domain and the seismic data is in the time domain. Obtaining reflection coefficient through sound wave and density data of single well, obtaining synthetic seismic record by convolution of seismic wavelet and reflection coefficient, calibrating synthetic recording section and seismic section passing through well, and converting depth domain data into time domain. The synthetic seismic record obtained by convolution of the reflection coefficient and the seismic wavelet can accurately establish a time-depth relation, so that the crack reservoir can be accurately determined.

EXAMPLE III

In modeling fracture impedance from the seismic data, the following process may be employed. Firstly, performing structure-oriented filtering processing on the seismic data to obtain filtered seismic data; then, carrying out fault automatic detection (AFE) calculation based on the filtered seismic data to obtain a middle fracture impedance model of the target area; the intermediate fracture impedance model includes AFE values; and finally, acquiring an AFE threshold corresponding to the target area, and determining the fracture impedance model based on the AFE threshold and an AFE value in the intermediate fracture impedance model.

When the fracture impedance model is determined based on the AFE threshold and the AFE value in the intermediate fracture impedance model, a constant impedance value corresponding to the target area may be obtained first; and then determining the AFE value larger than the AFE threshold value in the intermediate fracture impedance model as the constant impedance value, and determining the AFE value smaller than the AFE threshold value in the intermediate fracture impedance model as a null value to obtain the fracture impedance model.

Specifically, the structure-oriented filtering processing is carried out on the original seismic data, and the signal-to-noise ratio of the seismic data can be improved through the structure-oriented filtering of the seismic data, so that the continuous characteristic or the discontinuous characteristic of a seismic event is more obvious, the horizon and fault interpretation of the seismic data is facilitated, and meanwhile, a data basis is provided for the subsequent correlation calculation and fault identification. An AFE calculation is performed based on the filtered seismic data to obtain an AFE value. In addition, when the AFE threshold corresponding to the target area is obtained, the related data of the drilled fracture may be obtained, and then well-seismic calibration may be performed according to the obtained related data, so as to determine the AFE value corresponding to the position of the fracture, and the AFE value may be used as the AFE threshold of the fracture. When the fracture impedance model is determined based on the AFE threshold value and an AFE value in the intermediate fracture impedance model, replacing the AFE value which is greater than the AFE threshold value in the AFE value with an impedance value of a constant carbonate rock background, namely a fracture in a target area; the AFE values that are less than or equal to the AFE threshold are set to null values, i.e., non-fractures in the target region, to create an impedance model of the fracture.

And (5) replacing the null value part in the crack impedance model with the value corresponding to the initial low-frequency model in the step (S110) to obtain the mixed impedance low-frequency model.

Example four

Referring to fig. 2, the present application provides a fractured reservoir determination apparatus 200, the apparatus comprising:

an initial low-frequency model building module 210, configured to build an initial low-frequency model according to the acquired seismic data and logging data of the target area;

a fracture impedance model building module 220, configured to build a fracture impedance model according to the seismic data;

a mixed impedance low-frequency model determining module 230, configured to obtain a mixed impedance low-frequency model according to the initial low-frequency model and the fracture impedance model;

a longitudinal wave impedance data volume determining module 240, configured to perform inversion according to the mixed impedance low-frequency model, determine a longitudinal wave impedance data volume of the target area, and determine a spatial distribution of the target area based on the longitudinal wave impedance data volume;

and a fracture determining module 250, configured to obtain a relation function representing a relation between the compressional impedance data volume and the porosity, so as to determine the fracture reservoir based on the spatial distribution according to the relation function.

According to an embodiment of the present application, optionally, in the above fracture reservoir determining apparatus, the initial low-frequency model building module includes:

the well-seismic calibration unit is used for carrying out well-seismic calibration building time-depth relation based on the acquired well logging data and the acquired seismic data;

According to an embodiment of the application, optionally, in the above fracture reservoir determining apparatus, the well log data includes: acoustic data and density data for a single well, the seismic data comprising: seismic wavelet data, the well-seismic calibration unit comprising:

According to an embodiment of the present application, optionally, in the above fracture reservoir determining apparatus, the fracture impedance model determining unit includes:

a target longitudinal wave impedance data determination unit, configured to determine target longitudinal wave impedance data based on the longitudinal wave impedance data and a longitudinal wave impedance threshold;

In summary, the present application provides a fractured reservoir determination apparatus comprising: the initial low-frequency model establishing module is used for establishing an initial low-frequency model according to the acquired seismic data and the acquired logging data of the target area; the crack impedance model establishing module is used for establishing a crack impedance model according to the seismic data; the mixed impedance low-frequency model determining module is used for obtaining a mixed impedance low-frequency model according to the initial low-frequency model and the crack impedance model; a longitudinal wave impedance data volume determining module, configured to perform inversion according to the mixed impedance low-frequency model, determine a longitudinal wave impedance data volume of the target area, and determine a spatial distribution of the target area based on the longitudinal wave impedance data volume; and the fracture determining module is used for acquiring a relation function representing the relation between the longitudinal wave impedance data body and the porosity, and determining the fracture reservoir based on the spatial distribution according to the relation function. The method comprises the steps of establishing an initial low-frequency model according to seismic data and well logging data of a target area, establishing a fracture impedance model according to the seismic data, and then obtaining a mixed impedance low-frequency model according to the initial low-frequency model and the fracture impedance model, so that reservoir spreading can be described in longitudinal and transverse three-dimensional spaces according to the mixed impedance low-frequency model. And (3) inverting the mixed impedance low-frequency model to obtain a longitudinal wave impedance data volume of the target area, wherein the longitudinal wave impedance data volume can reflect information such as lithology and physical properties of the target area. Therefore, the spatial distribution of the fracture-cavity body in the target area can be accurately depicted according to the longitudinal wave impedance data body and the relation function of the relationship between the longitudinal wave impedance data body and the porosity, so that the fracture-cavity communication relationship of the reservoir can be visually depicted.

EXAMPLE five

The present embodiments also provide a computer readable storage medium, such as a flash memory, a hard disk, a multimedia card, a card type memory (e.g., SD or DX memory, etc.), a Random Access Memory (RAM), a Static Random Access Memory (SRAM), a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a programmable read-only memory (PROM), a magnetic memory, a magnetic disk, an optical disk, a server, an App, etc., having stored thereon a computer program which, when executed by a processor, may implement the method steps of:

Optionally, in the method for determining a fracture reservoir, step S110 includes the following steps:

carrying out well-seismic calibration building time-depth relation based on the obtained well logging data and the seismic data;

Optionally, in the method for determining a fracture reservoir, the well logging information includes: acoustic data and density data for a single well, the seismic data comprising: the seismic wavelet data, the well-seismic calibration time-depth relation established based on the acquired well logging data and the seismic data, comprises:

Optionally, in the method for determining a fracture reservoir, establishing a fracture impedance model according to the seismic data includes:

Optionally, in the method for determining a fracture reservoir, determining the fracture impedance model based on the AFE threshold and the AFE value in the intermediate fracture impedance model includes:

acquiring a constant impedance value corresponding to the target area;

Optionally, in the method for determining a fracture reservoir, performing inversion according to the mixed impedance low-frequency model, and determining a longitudinal wave impedance data volume of the target region, so as to determine a spatial distribution of the target region based on the longitudinal wave impedance data volume includes:

Optionally, in the method for determining a fracture reservoir, obtaining a relationship function representing a relationship between a longitudinal wave impedance data volume and porosity, and determining the fracture reservoir based on the spatial distribution according to the relationship function includes:

determining the fractured reservoir according to the porosity.

The specific embodiment process of the above method steps can be referred to as embodiment one, and the detailed description of this embodiment is not repeated herein.

EXAMPLE six

The embodiment of the application provides an electronic device, which may be a mobile phone, a computer, a tablet computer, or the like, and includes a memory and a processor, where the memory stores a computer program, and the computer program, when executed by the processor, implements the fracture reservoir determination method as described in the first embodiment. It is to be understood that, as shown in fig. 3, the electronic device 300 may further include: a processor 301, a memory 302, a multimedia component 303, an input/output (I/O) interface 304, and a communication component 305.

The processor 301 is configured to perform all or part of the steps of the method for determining a fractured reservoir according to the first embodiment. The memory 302 is used to store various types of data, which may include, for example, instructions for any application or method in the electronic device, as well as application-related data.

The Processor 301 may be implemented by an Application Specific Integrated Circuit (ASIC), a Digital Signal Processor (DSP), a Digital Signal Processing Device (DSPD), a Programmable Logic Device (PLD), a Field Programmable Gate Array (FPGA), a controller, a microcontroller, a microprocessor, or other electronic components, and is configured to execute the method for determining a fractured reservoir in the first embodiment.

The Memory 302 may be implemented by any type of volatile or non-volatile Memory device or combination thereof, such as Static Random Access Memory (SRAM), electrically Erasable Programmable Read-Only Memory (EEPROM), erasable Programmable Read-Only Memory (EPROM), programmable Read-Only Memory (PROM), read-Only Memory (ROM), magnetic Memory, flash Memory, magnetic disk or optical disk.

The multimedia component 303 may include a screen, which may be a touch screen, and an audio component for outputting and/or inputting audio signals. For example, the audio component may include a microphone for receiving an external audio signal. The received audio signal may further be stored in a memory or transmitted through a communication component. The audio assembly also includes at least one speaker for outputting audio signals.

The I/O interface 304 provides an interface between the processor 301 and other interface modules, such as a keyboard, mouse, buttons, etc. These buttons may be virtual buttons or physical buttons.

The communication component 305 is used for wired or wireless communication between the electronic device 300 and other devices. Wireless Communication, such as Wi-Fi, bluetooth, near Field Communication (NFC), 2G, 3G or 4G, or a combination of one or more of them, so that the corresponding Communication component 305 may include: wi-Fi module, bluetooth module, NFC module.

In summary, the method, the apparatus, the storage medium, and the electronic device for determining a fracture reservoir provided by the present application include: establishing an initial low-frequency model according to the acquired seismic data and the acquired logging data of the target area; establishing a fracture impedance model according to the seismic data; obtaining a mixed impedance low-frequency model according to the initial low-frequency model and the crack impedance model; performing inversion according to the mixed impedance low-frequency model, determining a longitudinal wave impedance data volume of the target area, and determining the spatial distribution of the target area based on the longitudinal wave impedance data volume; and acquiring a relation function representing the relation between the longitudinal wave impedance data volume and the porosity, and determining the fracture reservoir based on the spatial distribution according to the relation function. The method comprises the steps of establishing an initial low-frequency model according to seismic data and well logging data of a target area, establishing a fracture impedance model according to the seismic data, and then obtaining a mixed impedance low-frequency model according to the initial low-frequency model and the fracture impedance model, so that reservoir spreading can be described in longitudinal and transverse three-dimensional space according to the mixed impedance low-frequency model. And (3) inverting the mixed impedance low-frequency model to obtain a longitudinal wave impedance data volume of the target area, wherein the longitudinal wave impedance data volume can reflect information such as lithology and physical properties of the target area. Therefore, the spatial distribution of the fracture-cavity body in the target area can be accurately depicted according to the longitudinal wave impedance data body and the relation function of the relationship between the longitudinal wave impedance data body and the porosity, so that the fracture-cavity communication relationship of the reservoir can be more visually depicted.

In the several embodiments provided in the embodiments of the present application, it should be understood that the disclosed system and method may be implemented in other ways. The system and method embodiments described above are merely illustrative.

It should be noted that, in this document, 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, an element defined by the phrase "comprising a … …" does not exclude the presence of another identical element in a process, method, article, or apparatus that comprises the element.

Although the embodiments disclosed in the present application are described above, the descriptions are only for the convenience of understanding the present application, and are not intended to limit the present application. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the disclosure as defined by the appended claims.

Claims

1. A method for fracture reservoir determination, the method comprising:

establishing a fracture impedance model according to the seismic data;

2. The method of claim 1, wherein the obtaining seismic data and well log data for the target area creates an initial low frequency model comprising:

3. The method of claim 2, wherein the well log data comprises: acoustic data and density data for a single well, the seismic data comprising: seismic wavelet data, said well-seismic calibration build-time-depth relationship based on said acquired logging data and said seismic data, comprising:

4. The method of claim 1, wherein creating a fracture impedance model from the seismic data comprises:

5. The method of claim 4, wherein determining the fracture impedance model based on the AFE threshold and AFE values in the intermediate fracture impedance model comprises:

acquiring a constant impedance value corresponding to the target area;

6. The method of claim 1, wherein inverting from the mixed impedance low frequency model, determining a compressional impedance data volume for the target region, to determine a spatial spread of the target region based on the compressional impedance data volume comprises:

and determining the spatial position corresponding to the target longitudinal wave impedance data as the target area development space distribution.

7. The method of claim 1, wherein obtaining a relationship function representing a relationship between a compressional impedance data volume and porosity to determine the fractured reservoir based on the spatial spread according to the relationship function comprises:

determining the fractured reservoir according to the porosity.

8. A fractured reservoir determination apparatus, the apparatus comprising:

a longitudinal wave impedance data volume determining module, configured to perform inversion according to the mixed impedance low-frequency model, determine a longitudinal wave impedance data volume of the target area, and determine spatial distribution of the target area based on the longitudinal wave impedance data volume;

9. A storage medium storing a computer program which, when executed by one or more processors, is adapted to perform a method of fracture reservoir determination as claimed in any one of claims 1 to 7.

10. An electronic device comprising a memory and a processor, the memory having stored thereon a computer program that, when executed by the processor, performs a method of fracture reservoir determination as claimed in any one of claims 1 to 7.