阅读说明：本技术 T2谱反演方法、装置和存储介质 (T2 spectrum inversion method, device and storage medium ) 是由 肖承文 何宗斌 袁仕俊 张宫 海川 艾勇 朱雷 郭秀丽 李进福 李晓龙 于 2018-08-20 设计创作，主要内容包括：本发明提供一种T2谱反演方法、装置和存储介质,该方法包括：接收用户输入的布点数据；根据所述布点数据及相关采集参数,确定反演系数矩阵；采集多组回波数据,并根据所述多组回波数据分别对所述反演系数矩阵进行扩充处理,得到扩充后的反演系数矩阵；根据所述扩充后的反演系数矩阵,使用正负扫描算子,进行非负约束确定横向弛豫分量的初始幅度P。本发明实现了T2谱的反演,并提高了T2谱反演的速度和准确率。(The invention provides a T2 spectrum inversion method, a device and a storage medium, wherein the method comprises the following steps: receiving stationing data input by a user; determining an inversion coefficient matrix according to the stationing data and related acquisition parameters; collecting a plurality of groups of echo data, and respectively performing expansion processing on the inversion coefficient matrix according to the plurality of groups of echo data to obtain an expanded inversion coefficient matrix; and according to the expanded inversion coefficient matrix, carrying out non-negative constraint to determine the initial amplitude P of the transverse relaxation component by using a positive and negative scanning operator. The invention realizes the inversion of the T2 spectrum and improves the speed and accuracy of the inversion of the T2 spectrum.)

1. A method of T2 spectral inversion, comprising:

receiving stationing data input by a user;

determining an inversion coefficient matrix according to the point distribution data;

collecting a plurality of groups of echo data, and respectively performing expansion processing on the inversion coefficient matrix according to the plurality of groups of echo data to obtain an expanded inversion coefficient matrix;

and determining the initial amplitude P of the transverse relaxation component according to the expanded inversion coefficient matrix.

2. The method of claim 1, wherein determining an inversion coefficient matrix from the stationing data comprises:

receiving a user-entered logarithmic minimum T_2minSum logarithmic maximum T_2max；

According to the point distribution data and the logarithm minimum value T_2minAnd said logarithmic maximum T_2maxDetermining the transverse relaxation time T of the ith relaxation component_2i；

According to the T_2iAnd determining the inversion coefficient matrix.

3. The method of claim 1, wherein determining an inversion coefficient matrix from the stationing data comprises:

receiving a user-entered exponential minimum value T_2eminAnd exponential step increment Δ T_2e；

According to the distribution data and the index minimum value T_2eminAnd the exponential step increment Δ T_2eDetermining the transverse relaxation time T of the ith relaxation component_2i；

According to the T_2iAnd determining the inversion coefficient matrix.

4. Method according to claim 2 or 3, characterized in that said method is based on said T_2iDetermining the matrix of inversion coefficients, comprising:

receivingEcho interval value Te, echo starting sequence number Is and ending sequence number Ie, echo polarization time Tw and ratio T of longitudinal relaxation time to transverse relaxation time input by user_12R；

Calculating each time point t of the echo according to the echo interval value Te, the echo starting sequence number Is and the end sequence number Is_k；

According to the echo polarization time Tw and the ratio T of the longitudinal relaxation time to the transverse relaxation time_12RCalculating the polarization correction Pc_k,i；

According to each time point t of the echo_kAnd said polarization correction amount Pc_k,iAnd determining the inversion coefficient matrix.

5. The method according to any one of claims 1 to 3, wherein the respectively performing expansion processing on the inversion coefficient matrix according to the multiple sets of echo data to obtain an expanded inversion coefficient matrix comprises:

performing matrix transformation on the inversion coefficient matrix to obtain a transformed inversion coefficient matrix;

and according to the multiple groups of echo parameters, performing expansion processing on the transformed inversion coefficient matrix to obtain the expanded inversion coefficient matrix.

6. The method according to any of claims 1-3, wherein said determining an initial amplitude P of a transverse relaxation component from said augmented matrix of inversion coefficients comprises:

adopting a forward scanning operator to perform forward scanning on all diagonal elements in the expanded inversion coefficient matrix to obtain a forward scanning result;

judging whether a negative solution exists in the positive scanning result;

if the negative solution exists, determining the sequence number of the main diagonal element corresponding to the negative solution;

and determining the initial amplitude P of the transverse relaxation component according to the sequence number of the main diagonal element corresponding to the negative solution.

7. The method according to claim 6, wherein said determining an initial amplitude P of a transverse relaxation component from the sequence number of the main diagonal element corresponding to said negative solution comprises:

step A: according to the sequence number of the main diagonal element corresponding to the first largest negative solution in the negative solutions, performing negative scanning on the element corresponding to the sequence number by using a negative scanning operator to obtain a negative scanning result;

and B: judging whether negative solutions exist in the negative scanning result, if so, determining a second maximum negative solution in the negative scanning result as a new first maximum negative solution, and repeatedly executing the steps A-B until no negative solution exists in the negative scanning result;

and C: and determining the initial amplitude P of the transverse relaxation component according to the negative direction scanning result.

8. A T2 spectral inversion apparatus, comprising:

the receiving module is used for receiving the point distribution data input by the user;

the determining module is used for determining an inversion coefficient matrix according to the stationing data;

the processing module is used for acquiring a plurality of groups of echo data and respectively expanding the inversion coefficient matrix according to the plurality of groups of echo data to obtain an expanded inversion coefficient matrix;

the determining module is further configured to determine an initial amplitude P of the transverse relaxation component according to the extended inversion coefficient matrix.

9. A server, comprising:

a processor;

a memory; and

a computer program;

wherein the computer program is stored in the memory and configured to be executed by the processor, the computer program comprising instructions for performing the method of any of claims 1-7.

10. A computer-readable storage medium, characterized in that it stores a computer program that causes a server to execute the method of any one of claims 1-7.

Technical Field

The invention relates to the technical field of logging of geological exploration, in particular to a T2 spectrum inversion method, a T2 spectrum inversion device and a storage medium.

Background

When a Nuclear Magnetic Resonance (NMR) mode is used for logging, each echo signal measured by an actual instrument is the overall effect of multiple relaxation components. This can be expressed as a multi-exponential function:

wherein A (t) is the echo amplitude measured at the time t; t is_2iA transverse relaxation time, which is the ith relaxation component, used to characterize pore size; p_iIs the initial amplitude of the i transverse relaxation component that characterizes the porosity size of a pore of a characteristic relaxation size. Wherein, T_2iIn the inversion, a series of values are assumed in advance, after each characteristic relaxation and a characteristic relaxation component i are determined, an overdetermined equation set can be formed by combining echo strings, j is 1, …, k (k is the echo number), and P is obtained through the equation set_iThe process is called the inversion of T2 spectrum, and is the key to the nuclear magnetic resonance logging data processing. Inversion of the T2 spectrum is a typical morbidity problem, or ill-posed problem.

In recent years, research on NMR T2 spectrum inversion methods has been greatly advanced, many different inversion algorithms are available at home and abroad, and currently, MAP-II based on singular value decomposition is still a T2 spectrum inversion method widely adopted at present internationally. According to the method, a T2 spectrum inversion linear equation set is constructed, the solution of the linear equation set is solved for an actual problem by using a singular value decomposition method, and finally an inversion T2 spectrum with good continuity is obtained.

However, in the implementation process of the prior art, the number of actually measured echo strings is large, the memory overhead is large, and the inversion speed is slow. In order to improve the signal-to-noise ratio and the inversion speed, the echo train is generally required to be filtered, then a part of data is extracted for inversion, meanwhile, the number of distribution points of T2 is compressed, and finally, the inversion result is interpolated and smoothed, wherein the influence of the middle loop is large, and the efficiency is low.

Disclosure of Invention

The invention provides a method, a device and a storage medium for a T2 spectrum inversion algorithm, which are used for realizing concise and efficient T2 spectrum inversion.

In a first aspect, an embodiment of the present invention provides a T2 spectrum inversion method, including:

receiving stationing data input by a user;

determining an inversion coefficient matrix according to the point distribution data;

collecting a plurality of groups of echo data, and respectively performing expansion processing on the inversion coefficient matrix according to the plurality of groups of echo data to obtain an expanded inversion coefficient matrix;

and determining the initial amplitude P of the transverse relaxation component according to the expanded inversion coefficient matrix.

According to the scheme, the inversion coefficient matrix is determined according to the point distribution data input by a receiving user, the inversion matrix is prevented from being established back and forth according to each processing point in echo parameters, then multiple groups of echo data are collected, the inversion coefficient matrix is respectively subjected to expansion processing according to the multiple groups of echo data, the expanded inversion coefficient matrix is obtained, finally the initial amplitude P of the transverse relaxation component is determined according to the expanded inversion coefficient matrix, the inversion of the T2 spectrum is achieved, and the inversion efficiency of the T2 spectrum is improved by establishing the inversion coefficient matrix.

Optionally, determining an inversion coefficient matrix according to the stationing data includes:

log minimization for receiving user inputValue T_2minSum logarithmic maximum T_2max；

According to the point distribution data and the logarithm minimum value T_2minAnd said logarithmic maximum T_2maxDetermining the transverse relaxation time T of the ith relaxation component_2i；

According to the T_2iAnd determining the inversion coefficient matrix.

Optionally, determining an inversion coefficient matrix according to the stationing data includes:

receiving a user-entered exponential minimum value T_2eminAnd exponential step increment Δ T_2e；

According to the distribution data and the index minimum value T_2eminAnd the exponential step increment Δ T_2eDetermining the transverse relaxation time T of the ith relaxation component_2i；

According to the T_2iAnd determining the inversion coefficient matrix.

Optionally, said is according to said T_2iDetermining the matrix of inversion coefficients, comprising:

receiving an echo interval value Te, an echo start sequence number Is and an echo end sequence number Ie, an echo polarization time Tw and a ratio T of longitudinal relaxation time to transverse relaxation time input by a user_12R；

Calculating each time point t of the echo according to the echo interval value Te, the echo starting sequence number Is and the end sequence number Is_k；

According to the echo polarization time Tw and the ratio T of the longitudinal relaxation time to the transverse relaxation time_12RCalculating the polarization correction Pc_k,i；

According to each time point t of the echo_kAnd said polarization correction amount Pc_k,iAnd determining the inversion coefficient matrix.

In the scheme, each time point t of the echo Is calculated according to an echo interval value Te, an echo starting sequence number Is and the termination sequence number Is which are input by a user according to actual conditions_kEcho polarization time Tw and ratio T of longitudinal relaxation time to transverse relaxation time inputted by user according to actual situation_12RCalculating the polarization correction Pc_k,i(ii) a Finally, according to each time point t of the echo_kAnd polarization correction amount Pc_k,iThe inversion coefficient matrix is determined, and the inversion coefficient matrix is determined in the above mode, so that the inversion matrix is prevented from being established back and forth for each processing point of each group of echoes in the actual measurement process, a large amount of time is saved, and the calculation speed is improved.

Optionally, the performing expansion processing on the inversion coefficient matrix according to the multiple sets of echo parameters to obtain an expanded inversion coefficient matrix includes:

performing matrix transformation on the inversion coefficient matrix to obtain a transformed inversion coefficient matrix;

and according to the multiple groups of echo parameters, performing expansion processing on the transformed inversion coefficient matrix to obtain the expanded inversion coefficient matrix.

In the scheme, the inversion dimension is reduced by matrix transformation of the inversion coefficient matrix, the calculation speed is improved, the storage space is saved, the transformed inversion coefficient matrix is expanded according to a plurality of groups of echo parameters to obtain the expanded inversion coefficient matrix, and the operations of filtering, sampling, artificial dimension reduction and the like are avoided by introducing all measured data, so that the solving efficiency is improved.

Optionally, the determining an initial amplitude P of the transverse relaxation component according to the expanded inversion coefficient matrix includes:

adopting a forward scanning operator to perform forward scanning on all diagonal elements in the expanded inversion coefficient matrix to obtain a forward scanning result;

judging whether a negative solution exists in the positive scanning result;

if the negative solution exists, determining the sequence number of the main diagonal element corresponding to the negative solution;

and determining the initial amplitude P of the transverse relaxation component according to the sequence number of the main diagonal element corresponding to the negative solution.

Optionally, the determining an initial amplitude P of the transverse relaxation component according to the sequence number of the main diagonal element corresponding to the negative solution includes:

step A: according to the sequence number of the main diagonal element corresponding to the first largest negative solution in the negative solutions, performing negative scanning on the element corresponding to the sequence number by using a negative scanning operator to obtain a negative scanning result;

and B: judging whether negative solutions exist in the negative scanning result, if so, determining a second maximum negative solution in the negative scanning result as a new first maximum negative solution, and repeatedly executing the steps A-B until no negative solution exists in the negative scanning result;

and C: and determining the initial amplitude P of the transverse relaxation component according to the negative direction scanning result.

In the scheme, the diagonal elements in the expanded inversion coefficient matrix are positively scanned by adopting a positive scanning operator to obtain all solutions of a matrix equation, including a positive solution, a negative solution and a zero solution, and in the practical problem, because the negative solution has no significance, if the negative solution exists, the sequence number of the main diagonal element corresponding to the maximum negative solution in the negative solution is determined; and performing negative scanning according to the sequence number of the main diagonal element corresponding to the maximum negative solution to obtain a negative scanning result, updating the positive scanning result, then judging whether a negative solution exists in the updated scanning result, if so, determining a second maximum negative solution in the negative scanning result as a new first maximum negative solution, performing negative scanning on the sequence number of the main diagonal element corresponding to the new first maximum negative solution, repeating the steps until no negative solution exists in the negative scanning result, and finally determining the initial amplitude P of the transverse relaxation component according to the negative scanning result.

In a second aspect, an embodiment of the present invention provides a T-spectrum inversion apparatus, including

The receiving module is used for receiving the point distribution data input by the user;

the determining module is used for determining an inversion coefficient matrix according to the stationing data;

the processing module is used for acquiring a plurality of groups of echo data and respectively expanding the inversion coefficient matrix according to the plurality of groups of echo data to obtain an expanded inversion coefficient matrix;

the determining module is further configured to determine an initial amplitude P of the transverse relaxation component according to the extended inversion coefficient matrix.

Optionally, the determining module includes:

a receiving submodule for receiving the logarithm minimum value T input by the user_2minSum logarithmic maximum T_2max；

A determining submodule for determining the logarithm minimum T according to the point data_2minAnd said logarithmic maximum T_2maxDetermining the transverse relaxation time T of the ith relaxation component_2i；

The determination submodule is further used for determining the T_2iAnd determining the inversion coefficient matrix.

Optionally, the determining module includes:

a receiving submodule for receiving the index minimum value T input by the user_2eminAnd exponential step increment Δ T_2e；

A determining submodule for determining the index minimum value T according to the point data_2eminAnd the exponential step increment Δ T_2eDetermining the transverse relaxation time T of the ith relaxation component_2i；

A determination submodule for further determining a value based on the T_2iAnd determining the inversion coefficient matrix.

Optionally, the determining sub-module is specifically configured to:

receiving an echo interval value Te, an echo start sequence number Is and an echo end sequence number Ie, an echo polarization time Tw and a ratio T of longitudinal relaxation time to transverse relaxation time input by a user_12R；

Calculating each time point t of the echo according to the echo interval value Te, the echo starting sequence number Is and the end sequence number Is_k；

According to the echo polarization time Tw and the ratio T of the longitudinal relaxation time to the transverse relaxation time_12RCalculating the polarization correction Pc_k,i；

According to each time point t of the echo_kAnd said polarization correction amount Pc_k,iAnd determining the inversion coefficient matrix.

Optionally, the processing module is specifically configured to:

performing matrix transformation on the inversion coefficient matrix to obtain a transformed inversion coefficient matrix;

and according to the multiple groups of echo parameters, performing expansion processing on the transformed inversion coefficient matrix to obtain the expanded inversion coefficient matrix.

Optionally, the determining module includes:

the scanning submodule is used for carrying out forward scanning on all elements of the diagonal line in the expanded inversion coefficient matrix by adopting a forward scanning operator to obtain a forward scanning result;

the judgment submodule is used for judging whether a negative solution exists in the positive scanning result;

the determining submodule is used for determining the serial number of the main diagonal element corresponding to the negative solution when the judging submodule judges that the negative solution exists;

the determining submodule is further configured to determine an initial amplitude P of the transverse relaxation component according to the sequence number of the main diagonal element corresponding to the negative solution.

Optionally, the determining sub-module is specifically configured to:

step A: according to the sequence number of the main diagonal element corresponding to the first largest negative solution in the negative solutions, performing negative scanning on the element corresponding to the sequence number by using a negative scanning operator to obtain a negative scanning result;

and B: judging whether negative solutions exist in the negative scanning result, if so, determining a second maximum negative solution in the negative scanning result as a new first maximum negative solution, and repeatedly executing the steps A-B until no negative solution exists in the negative scanning result;

and C: and determining the initial amplitude P of the transverse relaxation component according to the negative direction scanning result.

In a third aspect, the present invention provides a server, comprising:

a processor;

a memory; and

a computer program;

wherein the computer program is stored in the memory and configured to be executed by the processor, the computer program comprising instructions for performing the method of the first aspect.

In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium, where a computer program is stored, and the computer program causes a server to execute the method in the first aspect.

According to the T2 spectrum inversion method, the T2 spectrum inversion device and the storage medium, the inversion coefficient matrix is determined according to the point distribution data input by a user, then, a plurality of groups of echo parameters are collected, the inversion coefficient matrix is subjected to expansion processing according to the plurality of groups of echo parameters, the expanded inversion coefficient matrix is obtained, and finally, the initial amplitude P of the transverse relaxation component is determined according to the expanded inversion coefficient matrix. Because the inversion matrix is prevented from being built back and forth according to each processing point by building the inversion coefficient matrix, the speed of T2 spectrum inversion is improved, and in addition, the inversion coefficient matrix is expanded according to a plurality of groups of echo parameters, the problem of inaccurate inversion result caused by operations such as filtering, sampling, artificial dimension reduction and the like is avoided, and the accuracy of T2 spectrum inversion is improved.

Drawings

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

FIG. 1 is a schematic flow chart of an embodiment of a T2 spectrum inversion algorithm method according to the present invention;

FIG. 2 is a schematic structural diagram of a first embodiment of a T2 spectrum inversion algorithm apparatus according to the present invention;

FIG. 3 is a schematic structural diagram of a second embodiment of a T2 spectrum inversion algorithm apparatus according to the present invention;

FIG. 4 is a schematic structural diagram of a third embodiment of a T2 spectrum inversion algorithm apparatus according to the present invention;

fig. 5 is a schematic structural diagram of a server according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are 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.