阅读说明：本技术 砾岩下伏构造变速成图方法及装置 (Variable-speed mapping method and device for conglomerate underlying structure ) 是由 许海涛 于宝利 景海璐 徐宝荣 刘新利 于 2019-10-11 设计创作，主要内容包括：本发明提供了一种砾岩下伏构造变速成图方法及装置,该方法包括：获取目标区域的地震资料、非地震资料和测井资料；根据地震资料、非地震资料和测井资料确定目标区域的上伏砾岩段层位模型,根据地震资料和测井资料确定目标区域的下伏层段层位模型；根据上伏砾岩段层位模型和地震资料生成上伏砾岩段层速度；基于下伏层段层位模型和测井资料进行反演得到波阻抗数据,并根据波阻抗数据确定下伏层段层速度；根据上伏砾岩段层速度、下伏层段层速度、上伏砾岩段层位模型和下伏层段层位模型生成目标区域的构造图。本发明可以提高砾岩下伏构造形态的预测精度。(The invention provides a variable-speed mapping method and a variable-speed mapping device for a conglomerate underlying structure, wherein the method comprises the following steps of: acquiring seismic data, non-seismic data and logging data of a target area; determining a horizon model of an upper glutenite section of the target area according to the seismic data, the non-seismic data and the logging data, and determining a horizon model of a lower layer of the target area according to the seismic data and the logging data; generating the velocity of the overlying conglomerate section according to the overlying conglomerate section horizon model and the seismic data; carrying out inversion based on the layer model of the underlying layer and the logging data to obtain wave impedance data, and determining the layer speed of the underlying layer according to the wave impedance data; and generating a structural diagram of the target area according to the velocity of the overlying conglomerate section layer, the velocity of the underlying layer section layer, the overlying conglomerate section layer model and the underlying layer model. The invention can improve the prediction precision of the conglomerate underlying structural form.)

1. A conglomerate underburden construction variable mapping method, comprising:

acquiring seismic data, non-seismic data and logging data of a target area;

determining a horizon model of an overlying conglomerate section of the target area according to the seismic data, the non-seismic data and the logging data, and determining a horizon model of an underlying interval of the target area according to the seismic data and the logging data;

generating the velocity of the overlying conglomerate section according to the overlying conglomerate section horizon model and the seismic data;

carrying out inversion based on the layer model of the underlying layer and the logging data to obtain wave impedance data, and determining the layer speed of the underlying layer according to the wave impedance data;

and generating a construction diagram of the target area according to the speeds of the overlying conglomerate section layers, the speed of the underlying layer section layer, the overlying conglomerate section layer model and the underlying layer model.

2. The conglomerate underburden variable speed mapping method of claim 1, wherein determining an overburden conglomerate segment horizon model for the target area from the seismic data, the non-seismic data, and the well log data comprises:

dividing the upper glutenite section into an earth surface glutenite part and a high-speed glutenite part according to the logging information;

determining the plane spread of the earth surface conglomerate part and the high-speed conglomerate part on the non-seismic data according to the electromagnetic characteristics of the overlying conglomerate section;

converting the plane spread on the non-seismic data into a time domain plane spread;

and fusing the plane spread of the time domain with the seismic data to obtain an upper glutenite section horizon model of the target area.

3. The method of shifting a conglomerate underburden configuration into a map as claimed in claim 1, wherein determining underburden layer velocities from the wave impedance data comprises:

converting the acoustic data of the logging data into speed data;

fitting the speed data and the wave impedance data to obtain a fitting result;

converting the wave impedance data into target speed data according to the fitting result;

and extracting the root mean square of the target speed data to obtain the layer speed of the underlying layer section.

4. The method of shifting a conglomerate underburden configuration into a map as recited in claim 1, wherein generating a map of the target area from the upper glutenite segment layer velocity, the underburden segment layer velocity, the upper glutenite segment layer level model, and the underburden layer level model comprises:

generating a time structure diagram according to the overlying conglomerate section horizon model and the underlying layer horizon model;

and generating a construction map of a target area according to the overlying conglomerate segment layer speed, the underlying layer segment layer speed and the time construction map.

5. The method of variable-speed mapping of a conglomerate underburden structure as claimed in claim 1, wherein inverting based on the underburden interval horizon model and the well log data to obtain wave impedance data comprises:

determining inversion control well data according to the logging data;

generating virtual control well data according to the variation trend of the thickness of the conglomerate;

and carrying out inversion based on the inversion control well data, the virtual control well data and the underlying interval layer model to obtain wave impedance data.

6. A conglomerate underburden variable speed mapping device, comprising:

the information acquisition module is used for acquiring seismic data, non-seismic data and logging data of a target area;

the horizon determining module is used for determining a horizon model of an overlying conglomerate section of the target area according to the seismic data, the non-seismic data and the logging data, and determining a horizon model of an underlying layer of the target area according to the seismic data and the logging data;

the upwelling speed module is used for generating the upwelling section layer speed according to the upwelling section layer model and the seismic data;

the underlying velocity module is used for carrying out inversion on the basis of the underlying layer model and the logging information to obtain wave impedance data and determining the underlying layer velocity according to the wave impedance data;

and the variable-speed mapping module is used for generating a structural map of the target area according to the speeds of the overlying conglomerate section layers, the speed of the underlying layer section layer, the overlying conglomerate section layer model and the underlying layer model.

7. A conglomerate underburden variable speed mapping apparatus as claimed in claim 6, wherein the horizon determining module is specifically configured to:

dividing the upper glutenite section into an earth surface glutenite part and a high-speed glutenite part according to the logging information;

determining the plane spread of the earth surface conglomerate part and the high-speed conglomerate part on the non-seismic data according to the electromagnetic characteristics of the overlying conglomerate section;

converting the plane spread on the non-seismic data into a time domain plane spread;

and fusing the plane spread of the time domain with the seismic data to obtain an upper glutenite section horizon model of the target area.

8. A conglomerate underburden construction variable-speed mapping device according to claim 6, characterized in that said underburden speed module, in particular, is adapted to:

converting the acoustic data of the logging data into speed data;

fitting the speed data and the wave impedance data to obtain a fitting result;

converting the wave impedance data into target speed data according to the fitting result;

and extracting the root mean square of the target speed data to obtain the layer speed of the underlying layer section.

9. Computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method according to any of the claims 1 to 5 when executing the computer program.

10. A computer-readable medium having non-volatile program code executable by a processor, the program code causing the processor to perform the method of any of the preceding claims 1 to 5.

Technical Field

The invention relates to the technical field of geophysical exploration, in particular to a method and a device for variable-speed mapping of a conglomerate underlying structure.

Background

The shallow layer of the mountain front oil and gas exploration favorable area generally develops the conglomerate alluvial sector in a plurality of periods, the longitudinal and transverse changes of the velocity of the conglomerate sector are severe, and the change of the plane thickness is large, so that the conglomerate underlying structural form displayed by the seismic data of a time domain can not accurately reflect the real structural form. The existing velocity mapping method for the gravelly rock underburden structure is mainly characterized in that under the control of a seismic horizon, a velocity field is established by utilizing a seismic velocity spectrum obtained in the seismic data processing process to calculate the horizon velocity, and after the velocity is restrained by drilling and logging, the variable velocity mapping is carried out.

The conventional seismic velocity field building and variable mapping method under the control of a velocity field formed by a drilling and logging velocity grid or a seismic horizon has the following problems in the application of a gravelly bedrock underlying construction area: conglomerate strata are in a disordered reflection characteristic in earthquake, the speed cannot be accurately picked up in the seismic data processing process, and the stratum speed corresponding to a conglomerate section obtained by establishing a speed field by using the seismic speed is low in precision; in the stratum section of the underburden normal stratum deposited by the conglomerate, the longitudinal interval of the seismic velocity spectrum points is generally 200ms-500ms, the stratum velocity precision obtained by utilizing the seismic velocity spectrum inversion is low, and the current fine exploration requirement cannot be met; logging data generally lack shallow data, and a velocity field formed by singly utilizing the drilling logging data cannot accurately reflect the velocity change of shallow conglomerates; conglomerate strata do not have a good tracking interface on a seismic section and cannot depict the change of the conglomerate form.

However, as the accuracy requirements for conglomerate underburden construction implementation in drilling deployments escalate, the requirements for "high accuracy" for velocity yards and variable mapping are also imposed.

Disclosure of Invention

The invention provides a variable-speed mapping method and device for a conglomerate underlying structure, which can improve the prediction precision of the form of the conglomerate underlying structure.

In a first aspect, embodiments of the present invention provide a conglomerate underburden variable mapping method, the method comprising: acquiring seismic data, non-seismic data and logging data of a target area; determining a horizon model of an overlying conglomerate section of the target area according to the seismic data, the non-seismic data and the logging data, and determining a horizon model of an underlying layer of the target area according to the seismic data and the logging data; generating the velocity of the overlying conglomerate section according to the overlying conglomerate section horizon model and the seismic data; carrying out inversion based on the layer model of the underlying layer and the logging data to obtain wave impedance data, and determining the layer speed of the underlying layer according to the wave impedance data; and generating a construction diagram of the target area according to the speeds of the overlying conglomerate section layers, the speed of the underlying layer section layer, the overlying conglomerate section layer model and the underlying layer model.

In a second aspect, embodiments of the present invention also provide a conglomerate underburden variable speed mapping device comprising: the information acquisition module is used for acquiring seismic data, non-seismic data and logging data of a target area; the horizon determining module is used for determining a horizon model of an overlying conglomerate section of the target area according to the seismic data, the non-seismic data and the logging data, and determining a horizon model of an underlying layer of the target area according to the seismic data and the logging data; the upwelling speed module is used for generating the upwelling section layer speed according to the upwelling section layer model and the seismic data; the underlying velocity module is used for carrying out inversion on the basis of the underlying layer model and the logging information to obtain wave impedance data and determining the underlying layer velocity according to the wave impedance data; and the variable-speed mapping module is used for generating a structural map of the target area according to the speed of the overlying conglomerate section layer, the speed of the underlying stratum layer, the overlying conglomerate section layer model and the underlying stratum layer model.

In a third aspect, the present invention further provides a computer device, including a memory and a processor, where the memory stores a computer program operable on the processor, and the processor executes the computer program to implement the conglomerate underlying structure shift mapping method.

In a fourth aspect, embodiments of the present invention also provide a computer readable medium having non-volatile program code executable by a processor, the program code causing the processor to perform the conglomerate underburden construction shift mapping method described above.

The embodiment of the invention has the following beneficial effects: the embodiment of the invention provides a conglomerate underlying structure variable-speed mapping scheme, which is characterized by acquiring seismic data, non-seismic data and logging data of a target area, determining an upper glutenite section horizon model of the target area based on the acquired seismic data, non-seismic data and logging data, determining an underlying layer horizon model of the target area based on the seismic data and the logging data, and then generating an upper glutenite section velocity according to the upper glutenite section horizon model and the seismic data; carrying out inversion based on the layer model of the underlying layer and the logging data to obtain wave impedance data, and determining the layer speed of the underlying layer according to the wave impedance data; thus, the structural map of the target region can be obtained through calculation. According to the method and the device, the accurate upper glutenite segment layer model is obtained through comprehensive analysis of non-seismic data, well logging data and seismic data, the accurate upper glutenite segment layer speed is obtained based on the upper glutenite segment layer model, the lower layer speed with higher resolution is obtained through wave impedance inversion calculation, the structural diagram of the target area is finally obtained, and the prediction accuracy of the glutenite lower structural form is improved.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a flow chart of a conglomerate underburden variable mapping method provided by an embodiment of the present invention;

FIG. 2 is a schematic diagram illustrating the results of a mathematical fit to the velocity of conglomerate using the log acoustic data, according to an embodiment of the present invention;

FIG. 3 is a schematic diagram illustrating the morphology of a conglomerate segment according to an audio magnetotelluric profile according to an embodiment of the present invention;

FIG. 4 is a velocity profile schematic of data conversion by wave impedance inversion provided by an embodiment of the present invention;

FIG. 5 is a block schematic diagram of a conglomerate underburden construction variable-speed patterning device structure provided by an embodiment of the present invention;

fig. 6 is a block diagram of a computer device according to an embodiment of the present invention.

Detailed Description

To make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is apparent that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

At present, a plurality of methods for converting seismic data of a time domain into a depth domain and further delineating a favorable construction area are provided, and whether the precise description of the thickness of the shallow layer conglomerate, the layer speed change and the medium-depth layer-layer speed can be accurately realized in the links of speed field building and variable-speed mapping in the method for realizing the conglomerate underlying construction is the key for accurately realizing the conglomerate underlying construction. Therefore, accurate depiction of the shallow conglomerate and accurate description of the intermediate and deep bed velocities, and further implementation of morphological details of the structure, is actually the delineation of the favorable structural target.

Generally speaking, velocity yarding and mapping of a conglomerate underburden construction is primarily composed of two parts:

1. well log, seismic and non-seismic data are used to describe the shallow conglomerate structure and calculate the conglomerate formation velocity.

And converting the acoustic time difference data in the logging data into speed data, wherein the acoustic time difference data AC is 1/V, wherein V is the acoustic speed, and therefore V is 1/AC.

When V is m/s and AC is μ s/m, V is 1/AC × 10⁶

When V is m/s and AC is μ s/ft, V is 10⁶/(AC×0.3048)

And performing approximate curve fitting according to the obtained speed data to determine the general rule of longitudinal change of the conglomerate in the research area. I.e. given data point P_i(V_i，h_i) Where i is 1, 2, …, m. Calculating an approximation curveAnd minimizes the deviation of the approximation curve from h ═ f (v). Deviation of the approximation curve at point Pii＝1，2，...，m。

The following three common curve fitting methods are mainly used:

(1) minimizing the sum of the absolute values of the deviations:

(2) minimize the maximum absolute value of the deviation:

(3) minimizing the sum of squared deviations:

among the many methods for predicting the lithologic distribution of conglomerate formations and their thickness, the Controlled Source Audio Magnetotelluric (CSAMT) method is one of them. The theoretical basis is a Maxwell equation set which comprises the following equations:

and D ε E

BμH

JσE

In the above formulas, E, D represents the proper amount of electric field strength and the vector of electric induction strength; ε is the dielectric constant of the medium; H. b is a magnetic field intensity vector and a magnetic induction intensity vector respectively; mu is the magnetic permeability of the medium; j is the current density vector and σ is the conductivity of the medium. In geophysical prospecting, the reciprocal ρ of σ is often used₁Referred to as resistivity; ρ is the charge density.

The CSAMT method has a good effect on predicting the morphology of the conglomerate, but the accuracy of the change in the conglomerate velocity needs to be further improved.

According to the method, the prediction data of the conglomerate structure in the depth domain are obtained through inversion according to a CSAMT method, the longitudinal speed change trend of the conglomerate is obtained through intersection of logging data, the inversion result of the CSAMT method is converted into a time domain result, and the time domain result is fused with the seismic profile and then combined with logging data to comprehensively explain the medium-shallow conglomerate structure.

And establishing a seismic velocity field according to the gravelly stratum bit data and the seismic velocity spectrum obtained by comprehensive interpretation, controlling the speed at the well point by adopting the geological knowledge general control trend, the drilling depth after the horizon calibration, and controlling the layer speed of a region far away from the drilling well by adopting the logging intersection analysis result, so that the speed plane change of the gravelly and shallowly gravels can be well implemented.

2. For the stratum interval of the underburden normal stratum deposited by the conglomerate, the stratum velocity of the stratum can be obtained by utilizing a wave impedance inversion technology, and the technology has the advantage that the obtained velocity has higher resolution in the longitudinal direction and the transverse direction.

The wave impedance inversion technology is based on three-dimensional seismic data, well logging data and construction interpretation data, and a wave impedance data volume with high resolution in the longitudinal direction and the transverse direction can be obtained by adopting various inversion methods.

Among the seismic wave impedance inversion methods, constrained sparse impulse inversion is one of the commonly used methods. The calculation process can be divided into three steps:

(1) reflection coefficient inversion: and (3) performing inversion of the reflection coefficient by adopting maximum likelihood deconvolution, wherein the assumption of the maximum likelihood deconvolution on the stratum is that: the reflection coefficient of the stratum is formed by superposition and combination of reflection of a larger reflection interface and small reflection with Gaussian background, and a minimum objective function is derived:

where R2 and N2 are the mean square values of the reflection coefficient and noise, respectively, R (K) and N (K) represent the reflection coefficient and noise for the Kth sample point, M represents the number of reflection layers, L represents the total number of samples, and λ represents the likelihood of a given reflection coefficient. And calculating the reflection coefficient through multiple iterations.

(2) According to the reflection coefficient obtained by the maximum likelihood deconvolution, combining with the initial impedance model, and adopting a recursion algorithm to obtain an initial wave impedance model by inversion:

wherein Z (i) is a wave impedance value of the i-th layer, and R (i) is a reflection coefficient of the i-th layer.

(3) And (3) carrying out wave impedance inversion by combining the constraint conditions of the well: and (3) the constraint sparse pulse inversion adjusts the initial wave impedance calculated by each channel according to the target function, including adjusting the reflection coefficient. The objective optimization function is:

F＝L_p(r)+λL_q(s-d)+α^-1L₁ΔZ

in the formula, r is a reflection coefficient sequence, Δ z is a difference sequence with an impedance trend, d is a seismic channel sequence, s is a synthetic seismic channel sequence, λ is a residual error weight factor, α is a trend weight factor, and p and q are L-mode factors. Specifically, the first term of the right equation reflects the sum of absolute values of the reflection coefficients, the second term reflects the difference between the synthetic acoustic record and the original seismic data, and the third term is a trend constraint term.

The mature successful experience of establishing velocity fields by wave impedance inversion is not seen at present. The reason is that the logging data is required to be restricted when wave impedance inversion is carried out, but the logging data is often lacked above the medium-shallow layer, and a complete data volume in the longitudinal direction cannot be obtained.

Based on the method and the device for variable-speed mapping of the conglomerate underlying structure, which are provided by the embodiment of the invention, the prediction of the conglomerate underlying structure form can be adapted by comprehensively utilizing various seismic and geological information and improving the conventional method.

To facilitate an understanding of the present embodiment, a conglomerate underburden variable mapping method as disclosed in the embodiments of the present invention will first be described in detail.

An embodiment of the present invention provides a conglomerate underlying structure variable-speed mapping method, which is shown in fig. 1, and the method comprises the following steps:

step S102, seismic data, non-seismic data and well logging data of the target area are obtained.

And S104, determining a layer position model of the overlying conglomerate section of the target area according to the seismic data, the non-seismic data and the logging data, and determining a layer position model of the underlying layer of the target area according to the seismic data and the logging data.

In the embodiment of the invention, the horizon model is used for describing the structure of the horizon, and the horizon model is obtained by comprehensively analyzing a plurality of information of seismic data, non-seismic data and logging data, thereby being beneficial to improving the formation mapping precision of the overlying conglomerate stratum. The overlying conglomerate segment horizon model may be a three-dimensional spatial model map.

It should be noted that the underlying interval horizon model may include only the horizon of the middle-deep layer or may include all the horizons of the middle-shallow layer and the middle-deep layer, and is determined according to actual requirements, and the embodiment of the present invention is not particularly limited. The underlying interval horizon model may be a three-dimensional spatial model map.

And S106, generating the velocity of the overlying conglomerate section according to the overlying conglomerate section layer model and the seismic data.

In the embodiment of the invention, the velocity field is established according to the horizon model of the overlying conglomerate section and the seismic velocity spectrum in the seismic data, so that the overlying conglomerate section velocity with higher accuracy can be obtained.

And S108, performing inversion based on the layer model of the underlying layer and the logging data to obtain wave impedance data, and determining the layer speed of the underlying layer according to the wave impedance data.

In the embodiment of the invention, the wave impedance inversion technology can be utilized to obtain the wave impedance data with higher resolution based on the underlying stratum layer model and the logging data, so that the underlying stratum layer speed with higher resolution can be obtained according to the wave impedance data.

Step S110, generating a structural diagram of the target area according to the velocity of the overlying conglomerate section layer, the velocity of the underlying layer section layer, the overlying conglomerate section layer model and the underlying layer model.

In the embodiment of the invention, the upper glutenite section layer model and the lower stratum layer model are respectively generated for the middle shallow layer and the middle deep layer, so that the upper glutenite section layer speed with higher accuracy and the lower stratum section layer speed with higher resolution can be obtained, and the construction diagram of the target area with higher precision can be obtained through variable-speed mapping.

The embodiment of the invention provides a variable-speed mapping method for a conglomerate underlying structure, which comprises the steps of obtaining seismic data, non-seismic data and logging data of a target area, determining an upper gravelly section horizon model of the target area based on the obtained seismic data, non-seismic data and logging data, determining an underlying layer horizon model of the target area based on the seismic data and the logging data, and then generating an upper gravelly section velocity according to the upper gravelly section horizon model and the seismic data; carrying out inversion based on the layer model of the underlying layer and the logging data to obtain wave impedance data, and determining the layer speed of the underlying layer according to the wave impedance data; thus, the structural map of the target region can be obtained through calculation. According to the method and the device, the accurate upper glutenite segment layer model is obtained through comprehensive analysis of non-seismic data, well logging data and seismic data, the accurate upper glutenite segment layer speed is obtained based on the upper glutenite segment layer model, the lower layer speed with higher resolution is obtained through wave impedance inversion calculation, the structural diagram of the target area is finally obtained, and the prediction accuracy of the glutenite lower structural form is improved.

In order to improve the accuracy of the overlying conglomerate segment horizon model, the overlying conglomerate segment horizon model of the target area is determined according to the seismic data, the non-seismic data and the logging data, and the method comprises the following steps of:

(1) and dividing the upper glutenite section into an earth surface glutenite part and a high-speed glutenite part according to the logging information.

In the embodiment of the invention, the acoustic time difference logging data is utilized, and the shallow layer conglomerate section is divided into two parts, namely earth surface conglomerate and high-speed conglomerate, according to the trend of speed change. The change of the speed and the thickness of the earth surface conglomerate section is more stable; the high velocity conglomerate segment varies dramatically in velocity and thickness.

(2) And determining the plane distribution of the earth surface conglomerate part and the high-speed conglomerate part on the non-seismic data according to the electromagnetic characteristics of the overlying conglomerate section.

In the embodiment of the invention, the electromagnetic profile can be obtained by a CSAMT method, the electromagnetic characteristics of the conglomerate are determined, and the plane spread of the conglomerate is preliminarily determined on non-seismic data by combining the ground surface conglomerate part and the high-speed conglomerate part obtained by interpretation.

(3) And converting the plane spread on the non-seismic data into the plane spread of a time domain.

In the embodiment of the invention, aiming at the conglomerate section, a mathematical relation fitting formula of the speed and the time depth can be determined through comparing and optimizing the layer speed with a plurality of parameters, and the plane spread on the non-seismic data can be converted into the plane spread of a time domain according to the fitting formula.

It should be noted that when the velocity of the overlying conglomerate section is generated based on the planar distribution of the time domain, the velocity at the well point can be controlled by using the geological knowledge general control trend and the drilling depth after the horizon calibration, and the velocity of the conglomerate section is constrained by using the above mathematical fitting formula for the region far away from the drilling well.

(4) And fusing the plane spread of the time domain with the seismic data to obtain an upper glutenite section horizon model of the target area.

And respectively confirming the plane spread of the time domain and the reflection characteristics of the conglomerates in the seismic data, and performing well drilling calibration, so as to accurately explain the seismic data and obtain the overlying conglomerate section horizon model of the target area.

Considering that the underlayer layer velocity is determined from the wave impedance data in order to improve the accuracy of the underlayer layer velocity, the following steps may be included:

converting acoustic data of the logging data into speed data; fitting the speed data and the wave impedance data to obtain a fitting result; converting the wave impedance data into target speed data according to the fitting result; and extracting the root mean square of the target speed data to obtain the layer speed of the underlying layer section.

In the embodiment of the invention, after the wave impedance data is obtained, the speed data and the wave impedance data are fitted to obtain a mathematical relation for describing the relation between the speed and the wave impedance data, and then the wave impedance data are converted into the target speed data according to the fitting result, and the root mean square of the target speed data is extracted to obtain the lower layer speed with higher precision.

Generating a structural diagram of the target area according to the speed of the overlying conglomerate section layer, the speed of the underlying layer section layer, the overlying conglomerate section layer model and the underlying layer model, wherein the structural diagram comprises the following steps:

generating a time structure diagram according to the overlying conglomerate section horizon model and the underlying layer horizon model; and generating a construction map of the target area according to the overlying conglomerate segment layer speed, the underlying layer segment layer speed and the time construction map.

In the embodiment of the invention, a shallow conglomerate horizon obtained by multi-information comprehensive interpretation is added, a control horizon model of an interpretation structure is established according to the speed interface optimization displayed by logging data of the middle-deep horizon, a time structure diagram is obtained, and then a depth domain structure diagram is obtained by utilizing the speed of an overlying conglomerate section layer, the speed of a lower layer section layer and the time structure diagram for operation, so that the structure diagram of a target area is obtained.

Carrying out inversion based on the underlying interval horizon model and logging information to obtain wave impedance data, wherein the wave impedance data comprises the following steps:

determining inversion control well data according to the logging data; generating virtual control well data according to the variation trend of the thickness of the conglomerate; and carrying out inversion based on the inversion control well data, the virtual control well data and the underlying interval layer model to obtain wave impedance data.

In the embodiment of the invention, the drilling and logging data with reasonable plane distribution, complete logging data and high seismic comprehensive calibration goodness of fit in a working area are preferably selected as the inversion control well, the virtual control well data are known and established according to the variation trend of the conglomerate thickness in the area far away from the drilling well, and the wave impedance data with higher resolution are obtained by proceeding wave impedance inversion based on the inversion control well data, the virtual control well data and the underlying layer position model.

It should be noted that wave impedance data with higher resolution can also be obtained by performing wave impedance inversion based on the inversion control well data and the underlying interval layer model, and the virtual control well data can determine whether to participate in wave impedance inversion according to actual requirements, which is not specifically limited by the embodiment of the present invention.

The embodiment of the invention provides a variable-speed mapping method and device for a conglomerate underburden structure. The main technical measures adopted are as follows: (1) preferably, the method is used for inverting control drilling and logging data in a research area, and the drilling and logging data which can be subjected to plane control, are complete in logging data and are high in seismic comprehensive calibration goodness of fit are selected as an inversion control well; (2) adding a shallow layer conglomerate layer obtained by multi-information comprehensive interpretation, and establishing an interpretation structure control layer model by optimizing a middle-deep layer according to a speed interface displayed by logging data; (3) and in a region far away from the well drilling, establishing a virtual well control shallow layer inversion result according to the conglomerate thickness variation trend recognition.

In order to meet the requirement of the actual structural form of a conglomerate underburden structural area, the method divides the stratum into two parts in the longitudinal direction according to the characteristics of a target area: first, conglomerate section; secondly, conglomerate underlying structural layer sections; and corresponding measures are respectively taken according to different characteristics of the two parts. The conglomerate structure is determined by combining logging data, non-seismic data and seismic data, and the conglomerate section velocity is realized through a fitted velocity-depth relation. By means of the wave impedance inversion technology, the longitudinal and transverse resolution of the underlying layer velocity is improved, and the velocity change of each underlying layer is described more accurately.

For a certain three-dimensional seismic region, the full coverage area of newly acquired two-dimensional data with width and height is 304km²Non-seismic audio magnetotelluric electricity is deployed in the middle and east of the three-dimensional seismic region, and the area is about 240km². The three-dimensional area has a plurality of oil fields, the oil and gas reservoirs are mainly structured oil and gas reservoirs, the main target layers are a Jurassic platform group, a three-room group and a Xishan kiln group, and the stratum burial depth is 2400 m-3700 m. The upper third and fourth series (0 m-18) of the local shallow layer00m) is a large alluvial fan mainly from a north matter source, and a high-speed gravel rock body is gradually thinned from north to south, so that the transverse change of the speed is large, and the time domain imaging cannot reflect the real occurrence of the underground stratum. Therefore, the key work of oil and gas exploration in the region is to accurately implement the structural form, and the speed change of the implementation of the shallow sandstone section is a key link for improving the accuracy of the structural diagram.

This area is through constructing into the realistic structural configuration of drawing, has two aspects problem to solve:

(1) the reflected energy of the shallow conglomerate on the earthquake is not focused, and the velocity pickup precision is low in the data processing process, so that a great error exists in mapping by using the earthquake velocity.

The solution is as follows: the structure and the speed change of the shallow conglomerate are combined and implemented by combining a plurality of data such as logging data, non-seismic data, seismic data and the like.

Calculating the velocity of the conglomerate section layer: according to the acoustic logging curve, the upwelling rock is divided into earth surface conglomerate and high-speed conglomerate through the speed change trend. The ground surface conglomerate has low speed but more drastic change, and is increased sharply along with the increase of the depth; the high-speed conglomerate has higher speed and more moderate change. The acoustic data of multiple wells is converted into layer velocity data, after comparison of fitting results of multiple parameters, a fitting formula of the mathematical relationship between the velocity of the conglomerate stratum and the time depth is determined to serve as two sets of conglomerate velocity change measuring plates, and a schematic diagram of the result of performing mathematical fitting on the velocity of the conglomerate by using the logging acoustic data is shown in fig. 2. On the basis of the research, the electromagnetic profile obtained by combining the CSAMT method determines the electromagnetic characteristics of two sets of conglomerates, preliminarily determines the depth domain plane distribution of the conglomerates on non-seismic data, and refers to a schematic diagram for explaining the form of the conglomerate section according to the audio magnetotelluric profile shown in FIG. 3. Converting the interpretation result of CSMAT into a time domain through the logging data segmentation intersection analysis result of the conglomerate stratum, combining the time domain with the seismic data for comprehensive calibration, implementing the seismic reflection characteristics of two sets of conglomerates, and reflecting the upper surface conglomerate seismic as weak amplitude; the reflection of the bottom boundary of the lower high-speed conglomerate shows medium and strong amplitude, so that the accurate interpretation is carried out on the seismic data, and the plane spread of the two sets of conglomerates on the time domain is determined. And establishing a seismic velocity field by adopting the gravelly stratum bit data and the seismic velocity spectrum obtained by comprehensive interpretation, controlling the well point velocity according to the geological knowledge general control trend, the drilling depth after the horizon calibration, and controlling the stratum velocity of a region far away from the drilling well according to the logging intersection analysis result, so that the velocity plane change of the gravelly and shallowly gravels can be well implemented. The whole change of the corrected speed is basically consistent with that before correction, and the speed is in a form of high north and south, but has larger change on the change gradient and detail, so that the speed change after correction is more reasonable.

(2) The time interval of deep data in the seismic velocity spectrum is large, generally 200ms-500ms, and the precision of thin-layer velocity inversion is low, so that the requirements of current fine exploration cannot be met.

The solution is as follows: and (5) adopting a method of combining seismic inversion with velocity field building to realize the velocity of the conglomerate underlying stratum.

And (3) calculating the layer velocity of the conglomerate underlying layer section: and optimizing the drilling and logging data with reasonable plane distribution, complete logging data and high seismic comprehensive calibration goodness of fit in a work area as an inversion control well, adding a shallow conglomerate layer obtained by multi-information comprehensive interpretation, optimizing the middle-deep layer according to a speed interface displayed by the logging data, establishing an interpretation structure control layer model, and establishing virtual control well data according to conglomerate thickness variation trend recognition in an area far away from the drilling well. And performing wave impedance inversion by adopting a constraint sparse pulse inversion method to obtain high-precision wave impedance data. The wave impedance volume obtained by inversion is converted into a velocity volume by a mathematical relation between wave impedance data and layer velocity data obtained by a multi-well intersection method, see a velocity profile schematic diagram of data conversion obtained by wave impedance inversion shown in fig. 4, wherein a plurality of black vertical lines in the diagram represent the positions of wells. And extracting interlayer data from the velocity body obtained by conversion to obtain the layer velocity of each set of stratum. The speed data obtained by inversion has clear longitudinal speed change rule, reasonable plane change rule, accurate detail description and higher precision.

By implementing the technology, a plurality of sets of target layer structure forms are implemented, and errors of the actual drilling result and the predicted horizon of the newly drilled well after implementation are less than 0.5%.

An embodiment of the present invention further provides a device for varying the speed of a conglomerate underburden structure into a diagram, see fig. 5, for a conglomerate underburden structure into a diagram, the device comprising:

the information acquisition module 51 is used for acquiring seismic data, non-seismic data and logging data of a target area; the horizon determining module 52 is configured to determine a horizon model of an overlying conglomerate section of the target area according to the seismic data, the non-seismic data, and the logging data, and determine a horizon model of an underlying layer of the target area according to the seismic data and the logging data; the upwelling velocity module 53 is used for generating the upwelling section velocity according to the upwelling section horizon model and the seismic data; the underlying velocity module 54 is configured to perform inversion based on the underlying interval layer model and the logging data to obtain wave impedance data, and determine an underlying interval layer velocity according to the wave impedance data; and the variable-speed mapping module 55 is configured to generate a structural map of the target area according to the overlying gravel section layer speed, the underlying layer section layer speed, the overlying gravel section layer model and the underlying layer model.

In an embodiment, the level information determining module is specifically configured to: dividing the upper gravelly section into an earth surface gravelly section and a high-speed gravelly section according to the logging information; determining the plane spread of the earth surface conglomerate part and the high-speed conglomerate part on the non-seismic data according to the electromagnetic characteristics of the overlying conglomerate section; converting the plane spread on the non-seismic data into a time domain plane spread; and fusing the plane spread of the time domain with the seismic data to obtain an upper glutenite section horizon model of the target area.

In one embodiment, the underlying velocity module is specifically for: converting acoustic data of the logging data into speed data; fitting the speed data and the wave impedance data to obtain a fitting result; converting the wave impedance data into target speed data according to the fitting result; and extracting the root mean square of the target speed data to obtain the layer speed of the underlying layer section.

In one embodiment, the shift mapping module is specifically configured to: generating a time structure diagram according to the overlying conglomerate section horizon model and the underlying layer horizon model; and generating a construction map of the target area according to the overlying conglomerate segment layer speed, the underlying layer segment layer speed and the time construction map.

In one embodiment, the underlying velocity module is specifically for: determining inversion control well data according to the logging data; generating virtual control well data according to the variation trend of the thickness of the conglomerate; and carrying out inversion based on the inversion control well data, the virtual control well data and the underlying interval layer model to obtain wave impedance data.

The embodiment of the present invention further provides a computer device, referring to the schematic block diagram of the structure of the computer device shown in fig. 6, the computer device includes a memory 61 and a processor 62, the memory stores a computer program that can be executed on the processor, and the processor implements the steps of any one of the methods when executing the computer program.

It is clearly understood by those skilled in the art that, for convenience and brevity of description, the specific working process of the computer device described above may refer to the corresponding process in the foregoing method embodiments, and no further description is provided herein

Embodiments of the present invention also provide a computer readable medium having non-volatile program code executable by a processor, the program code causing the processor to perform any of the steps of the above-described method.

As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention 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 present invention is described with reference to flowchart illustrations and/or block diagrams of methods 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.

Finally, it should be noted that: the above-mentioned embodiments are only specific embodiments of the present invention, which are used for illustrating the technical solutions of the present invention and not for limiting the same, and the protection scope of the present invention is not limited thereto, although the present invention is described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: any person skilled in the art can modify or easily conceive the technical solutions described in the foregoing embodiments or equivalent substitutes for some technical features within the technical scope of the present disclosure; such modifications, changes or substitutions do not depart from the spirit and scope of the embodiments of the present invention, and they should be construed as being included therein. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.