CN112177606B

CN112177606B - Measurement data compensation method and device of multi-frequency electric imaging equipment

Info

Publication number: CN112177606B
Application number: CN202010984718.4A
Authority: CN
Inventors: 卢涛; 于增辉; 刘耀伟; 王芝环; 贾立柱; 欧阳帅玉; 刘保银; 张中庆
Original assignee: China Oilfield Services Ltd
Current assignee: China Oilfield Services Ltd
Priority date: 2020-09-18
Filing date: 2020-09-18
Publication date: 2022-10-14
Anticipated expiration: 2040-09-18
Also published as: CN112177606A

Abstract

The utility model discloses a measurement data compensation method of a multi-frequency electrical imaging device, which comprises the steps of determining the formation resistivity according to the logging data measured by the multi-frequency electrical imaging device, and determining the formation dielectric constant according to the formation resistivity; determining a compensation weight factor matrix of the button electrode measuring point according to the stratum dielectric constant, the stratum resistivity and the spatial position information of the button electrode measuring point of the multi-frequency electrical imaging equipment; and respectively carrying out signal compensation processing on the formation dielectric constant and the formation resistivity according to the compensation weight factor matrix to obtain the compensated formation resistivity and the formation dielectric constant.

Description

Measurement data compensation method and device of multi-frequency electric imaging equipment

Technical Field

The present disclosure relates to, but not limited to, the field of oilfield development technologies, and in particular, to a method and an apparatus for compensating measured data of a multi-frequency electrical imaging device.

Background

The imaging logging instrument has high-density array button electrode arrangement, can provide a well wall imaging graph with high resolution and high well bore coverage rate, and the imaging interpretation of the imaging logging instrument reveals a new chapter of oil-gas interpretation, and can intuitively acquire geological information such as lithology, stratum sedimentary structure, crack characteristics and the like from the imaging graph. Imaging well logging techniques play an increasingly important role in addressing the ongoing exploration and development of oil and gas with increasing development difficulties.

The development of electrical imaging logging technology was in the 80's of the 20 th century. Schlumberger corporation introduced a first generation microresistivity scanning imager FMS for imaging in water-based mud wells, with a wall coverage of 20% as measured in 8.5in wellbores. In order to improve the coverage rate of the well wall, the Schlumberger company developed a whole-well formation micro-resistivity scanning imaging logging instrument FMI in 1991, each pushing arm of the instrument is provided with a main polar plate and a folding polar plate, the instrument can reach 80% of the coverage rate of the well wall when measuring in a 8.5-inch well, and the provided formation information is very rich. In 2013, schlumberger introduced a new generation of high-resolution electric imaging instrument FMI-HD, which can be applied to a part oil-based mud environment, and at the same time, has a significant improvement in electronic circuits. After schrenberger, the hall introduced the microresistivity borehole wall imaging logger EMI in 1995, which was developed based on the six-armed dip angle technique and had a six-plate double-row 150-electrode structure. Then Haributton company has introduced an EMI improved microresistivity imaging logging instrument XRMI, and the resistivity measurement range reaches 0.2-10000 omega.m. Subsequently, the atlas company also introduced a borehole wall microresistivity imaging tool of STARII type 6 plate 144 button electrode configuration with a borehole wall coverage of 60% for 8.5in borehole measurements. The STAR series instrument STAR-XR, newly introduced by beckhaus in 2019, increased 30% in wellbore coverage. On the basis of pushing out single-frequency oil-based electrical imaging logging instrument OGIT, the multi-frequency electrical imaging logging instrument MFIT suitable for the non-conductive oil-based mud environment is developed by the domestic medium-sea oil jacket, has a measurement function in a water-based environment, and can simultaneously acquire formation electrical response information under three working frequencies.

Along with the gradual trend of offshore exploration to the deep layer, high temperature and high pressure, mud system diversification lead to the borehole environment unusually harsh, and the condition that some polar plate images that still can appear under some environment simultaneously cause such as instrument card pause, polar plate paste the circumstances that log in image quality descends such as part polar plate image blurring has comparatively serious interference to the understanding of stratum characteristic. The existing single-frequency electrical imaging measurement cannot well meet the high-quality imaging measurement under complex well conditions, so that the multi-frequency electrical imaging measurement becomes a development trend, more abundant logging information is provided due to the measurement characteristics of multiple frequencies and multiple detection depths, the measurement requirements under complex well bores and formation environments can be met, high-quality imaging data are obtained through multi-frequency data processing, and more reliable logging data are provided for formation evaluation and geological interpretation.

Disclosure of Invention

The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

The embodiment of the disclosure provides a measurement data compensation method and a measurement data compensation device for a multi-frequency electrical imaging device, which can compensate logging data based on measurement (acquisition), solve the problems of inaccurate logging data, unclear final image and low resolution ratio under a complex borehole environment, and improve the accuracy of the acquired logging data.

The disclosed embodiment provides a measurement data compensation method of a multi-frequency electrical imaging device, which comprises,

determining formation resistivity according to logging data obtained by measuring through multi-frequency electrical imaging equipment, and determining a formation dielectric constant according to the formation resistivity;

determining a compensation weight factor matrix of the button electrode measuring point according to the stratum dielectric constant, the stratum resistivity and the spatial position information of the button electrode measuring point of the multi-frequency electrical imaging equipment;

and respectively carrying out signal compensation processing on the formation dielectric constant and the formation resistivity according to the compensation weight factor matrix to obtain the compensated formation resistivity and the formation dielectric constant.

In some exemplary embodiments, the determining a compensation weight factor matrix of button electrode measuring points according to the formation dielectric constant, the formation resistivity and the spatial position information of the button electrode measuring points of the multi-frequency electrical imaging device comprises:

determining a response space distribution function of button electrode measuring points of the multi-frequency electrical imaging equipment according to the stratum dielectric constant and the stratum resistivity;

determining the integral value of the response signal of each button electrode measuring point according to the spatial position information of the button electrode measuring point, the response spatial distribution function of the button electrode measuring point, the formation resistivity and the formation dielectric constant corresponding to the button electrode measuring point;

determining an offset correction matrix of each button electrode measuring point according to the integral value of the response signal of each button electrode measuring point and the area integral values of all the adjacent button electrode measuring points in the preset range of each button electrode measuring point;

and determining a compensation weight factor matrix of each button electrode measuring point according to the integral value of the response signal of each button electrode measuring point and the offset correction matrix.

In some exemplary embodiments, before the extracting the formation resistivity, the method further comprises:

step 0, preprocessing the logging data;

the pretreatment at least comprises one of the following treatments: abnormal data detection and elimination, card encountering processing, electric buckle depth correction and data resampling.

In some exemplary embodiments, the well log data comprises impedance values;

the method for determining the formation resistivity according to the logging data obtained by the multi-frequency electrical imaging equipment measurement and determining the formation dielectric constant according to the formation resistivity comprises the following steps:

extracting the formation resistivity from a pre-established resistivity scale coefficient sequence according to the impedance value and the corresponding working frequency in the logging data;

and extracting the stratum dielectric constant from the pre-established dielectric constant-resistivity explanation plate library according to the stratum resistivity.

In some exemplary embodiments, the determining a response spatial distribution function of button electrode measuring points of the multi-frequency electrical imaging device according to the formation dielectric constant and the formation resistivity comprises:

for each button electrode measuring point, the following steps are carried out to determine a response space distribution function of each button electrode measuring point:

forming a stratum model according to the structural parameters and the working frequency of the multi-frequency electric imaging equipment, the stratum resistivity of the button electrode measuring point and the stratum dielectric constant of the button electrode measuring point;

determining a response space distribution function of the button electrode measuring point by using a numerical simulation method aiming at the stratum model according to the currently measured borehole parameters of the multi-frequency electric imaging equipment; the wellbore parameters include at least: borehole radius, mud resistivity, mud dielectric constant;

the step of determining an integral value of a response signal of each button electrode measuring point according to the spatial position information of the button electrode measuring point, the response spatial distribution function of the button electrode measuring point, the formation resistivity and the formation dielectric constant corresponding to the button electrode measuring point comprises the following steps:

for each button electrode measurement point of the multi-frequency electrical imaging device, determining an integrated value of the response signal for that button electrode measurement point according to the following:

taking the button electrode measuring point as the center, selecting 2N +1 rows and 2M +1 columns of button electrode measuring points to form a button electrode measuring array of the button electrode measuring point, wherein N, M are positive integers; calculating the signal detection range of the button electrode according to the spatial position information of the button electrode measuring point, and the formation resistivity and the formation dielectric constant corresponding to the button electrode measuring point, and determining an integral area; integrating the response space distribution function of the button electrode measuring point in the integration area to obtain an integration value of the response signal of the button electrode measuring point;

the method for determining the offset correction matrix of each button electrode measuring point according to the integral value of the response signal of each button electrode measuring point and the integral value of the area of all the button electrode measuring points adjacent to each button electrode within the preset range of each button electrode measuring point comprises the following steps:

for each button electrode measuring point of the multi-frequency electrical imaging device, determining an offset correction matrix of the button electrode measuring point according to the following modes:

calculating the integral value of the response space distribution function of each adjacent button electrode measuring point in the integral area of the button electrode measuring point one by one according to the adjacent button electrode measuring points in the button electrode measuring array of the button electrode measuring point; forming a first matrix according to the spatial row-column positions of the button electrode measuring points in the button electrode measuring array of the button electrode measuring points, the integral values of all the adjacent button electrode measuring points obtained by arrangement calculation and the integral value of the response signal of the central button electrode measuring point, and taking the inverse number of the elements in the first matrix to form an offset correction matrix of each button electrode measuring point;

the method for determining the compensation weight factor matrix of each button electrode measuring point according to the integral value of the response signal of each button electrode measuring point and the offset correction matrix comprises the following steps:

for each button electrode measuring point of the multi-frequency electric imaging device, determining a compensation weight factor matrix of the button electrode measuring point according to the following modes:

replacing the elements at the corresponding positions in the offset correction matrix of the button electrodes by using the ratio of the elements in the offset correction matrix of the button electrode measuring points to the central elements of the first matrix; replacing a central element in an offset correction matrix of the button electrode measuring point by using the ratio of the integral value of the response signal of the button electrode measuring point to the central element of the first matrix, wherein the replaced offset correction matrix is a compensation coefficient matrix of the button electrode measuring point;

and carrying out normalization processing on the compensation coefficient matrix of the button electrode measuring point, and converting the compensation coefficient matrix into a compensation weight factor matrix of the button electrode measuring point.

In some exemplary embodiments, the performing signal compensation processing on the formation dielectric constant and the formation resistivity according to the compensation weight factor matrix to obtain compensated formation resistivity and formation dielectric constant includes:

and respectively determining the compensated formation resistivity and the formation dielectric constant of each button electrode measuring point of the multi-frequency electrical imaging equipment by the following methods:

performing inner product on the compensation weight factor matrix of the button electrode measuring point and the formation resistivity matrix of the button electrode measuring point to obtain a resistivity compensation quantity matrix, and performing inner product on the compensation weight factor matrix of the button electrode measuring point and the formation dielectric constant matrix of the button electrode measuring point to obtain a dielectric constant compensation quantity matrix;

accumulating the elements of the resistivity compensation quantity matrix one by one to be used as the formation resistivity compensated by the button electrode measuring point;

accumulating the elements of the dielectric constant compensation quantity matrix one by one to be used as the stratum dielectric constant compensated by the button electrode measuring point;

wherein, the formation resistivity matrix of the button electrode measuring point comprises: forming a stratum resistivity matrix of the button electrode measuring points according to the stratum resistivity and the corresponding positions respectively determined by the button electrode measuring points in the button electrode measuring array of the button electrode measuring points; the stratum dielectric constant matrix of the button electrode measuring point comprises: and forming a stratum dielectric constant matrix of the button electrode measuring points according to the stratum dielectric constants and the corresponding positions respectively determined by the button electrode measuring points in the button electrode measuring array of the button electrode measuring points.

In some exemplary embodiments, the resistivity scale factor sequence is established according to the following:

establishing a first uniform infinite thick stratum model, and changing the stratum resistivity and the mud resistivity of the first uniform infinite thick stratum model according to a preset sampling step length within a preset resistivity range to form a first stratum model sequence, wherein the stratum resistivity and the mud resistivity are the same in each change;

respectively calculating an impedance value corresponding to each first uniform infinite-thickness stratum model in the first stratum model sequence by adopting a three-dimensional finite element multi-frequency electrical imaging simulation algorithm;

respectively taking the ratio of the formation resistivity of each first uniform infinite thick formation model to the calculated impedance value as a scale coefficient of the uniform infinite thick formation model;

arranging the scale coefficients of all first uniform infinite thick stratum models in the first stratum model sequence according to a preset sequence to form the resistivity scale coefficient sequence;

the extracting the formation resistivity from the pre-established resistivity scale coefficient sequence comprises:

and respectively executing the following steps on the impedance value of each button electrode measuring point included in the logging data, and extracting the corresponding formation resistivity:

and according to the impedance value of the button electrode measuring point, inquiring a resistivity scale coefficient sequence under the corresponding working frequency to obtain a corresponding scale coefficient, calibrating the impedance value into resistivity by taking the product of the scale coefficient and the impedance value as the resistivity, and sectionally selecting the calibrated resistivity according to the applicable resistivity range of different frequencies as the formation resistivity of the button electrode measuring point.

In some exemplary embodiments, the dielectric constant-resistivity explanation plate is established according to the following manner:

establishing a second uniform infinite thick stratum model, and changing the mud resistivity, the stratum resistivity, the mud dielectric constant and the stratum dielectric constant of the second uniform infinite thick stratum model according to a preset resistivity sampling step length and a preset stratum dielectric constant sampling step length in a preset stratum resistivity range and a preset stratum dielectric constant range to form a second stratum model sequence; wherein the formation resistivity and the mud resistivity are the same in each change, and the formation dielectric constant and the mud dielectric constant are the same;

respectively calculating the impedance value of each second uniform infinite thick stratum model in the second stratum model sequence;

drawing a dielectric constant-resistivity explanation plate according to the stratum resistivity, the stratum dielectric constant and the calculated impedance value of each second uniform infinite thick stratum model in the second stratum model sequence;

the extracting the formation permittivity from the pre-established permittivity-resistivity interpretation template according to the formation resistivity comprises:

and respectively executing the following steps on the impedance value of each button electrode measuring point included in the logging data, and extracting the corresponding stratum dielectric constant:

and calculating the distance corresponding to the impedance value of the button electrode measuring point according to the dielectric constant-resistivity explanation plate and the distance function, and selecting the stratum dielectric constant corresponding to the minimum distance as the stratum dielectric constant of the button electrode measuring point.

An embodiment of the present disclosure further provides an electronic apparatus, which includes a memory and a processor, where the memory stores a computer program, and the processor is configured to run the computer program to perform the measurement data compensation method of the multi-frequency electrical imaging device.

The embodiment of the disclosure also provides a storage medium, in which a computer program is stored, wherein the computer program is configured to execute the measurement data compensation method of the multi-frequency electrical imaging apparatus when running.

Other aspects will be apparent upon reading and understanding the attached figures and detailed description.

Drawings

FIG. 1 is a flow chart illustrating a method for compensating measurement data of a multi-frequency electrical imaging apparatus according to an embodiment of the present disclosure;

FIG. 2 is a flowchart illustrating a method for compensating measurement data of a multi-frequency electrical imaging apparatus according to another embodiment of the disclosure;

FIG. 3 is an exemplary graph of resistivity scale factor versus impedance curves in embodiments of the present disclosure;

FIG. 4 is a schematic diagram of a dielectric constant-resistivity interpretation plate in an embodiment of the disclosure;

FIG. 5 is a diagram illustrating an exemplary distribution of button electrode log response signals in three-dimensional space in an embodiment of the present disclosure;

FIG. 6 is a schematic diagram of a button electrode measurement matrix selection in an embodiment of the present disclosure;

FIG. 7 is a graph of a sharp comparison of an electrographic image obtained from data processed by a method according to an embodiment of the disclosure and an electrographic image before processing;

fig. 8 is an exemplary diagram of an electrode of a multi-frequency electrical imaging apparatus employed in an embodiment of the present disclosure.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings and specific embodiments. It should be noted that the embodiments and features of the embodiments in the present application may be arbitrarily combined with each other without conflict.

The following description of the present disclosure relates to formation models whose model parameters include the relationships: parameters in the wellbore, mud, gap, surrounding rock, formation, etc., for example, include one or more of the following: formation boundary, well diameter, mud resistivity, mud dielectric constant, plate gap, formation resistivity, formation dielectric constant, surrounding rock resistivity, surrounding rock dielectric constant and the like.

The uniform infinite thick stratum model recorded in the disclosure belongs to a specific stratum model, and a three-layer huge thick stratum model can be adopted to replace the uniform infinite thick stratum model, namely, the layer interface of the stratum model can be set to be-1000 m and 1000m, and the midpoint of the equipment is placed at the position of 0m in depth.

A multi-frequency electrical imaging apparatus in some exemplary embodiments of the present disclosure includes a plurality of button electrodes; for example, as shown in fig. 8, the electrode comprises 6 electrode plates, 15 button electrodes are arranged in two rows on each electrode plate, the measurement data are arranged in a row in the order of the center position of the button, 90 button electrodes are arranged in total, and the measurement values of 90 button electrodes are enclosed into a circle. And one complete measurement, namely, according to the well depth or the depth range of the well to be imaged, arranging the multi-frequency electric imaging equipment at a plurality of depth positions according to a preset distance interval, respectively measuring the impedance signal of each electrode button under a plurality of frequencies (for example, 3 frequencies: 5MHz, 1MHz and 200 KHz), and obtaining the impedance signal through the measurement under different depths and different frequencies. Each button electrode corresponds to an electrode measuring point, which is called measuring point for short, at each depth position. Taking the example that one complete measurement includes measurements at 10 depths, 90 button electrodes correspond to 90 × 10 measurement points.

The reference numerals of the related steps in the following description indicate different execution steps, and the execution order of the related steps in the various embodiments is not limited only by the order of the reference numerals. "first stratigraphic model", "second stratigraphic model", represent different stratigraphic models, but do not define priorities, execution orders or other attributes; "first sequence of formation models", "second sequence of formation models", represent different sequences of formation models, but do not define priorities, execution orders or other attributes.

Example one

The embodiment of the present disclosure provides a method for compensating measurement data of a multi-frequency electrical imaging device, as shown in fig. 1, including:

step 1, determining formation resistivity according to logging data obtained by measuring through multi-frequency electrical imaging equipment, and determining a formation dielectric constant according to the formation resistivity;

step 2, determining a compensation weight factor matrix of the button electrode measuring point according to the stratum dielectric constant, the stratum resistivity and the spatial position information of the button electrode measuring point of the multi-frequency electrical imaging equipment;

and 3, respectively performing signal compensation processing on the formation dielectric constant and the formation resistivity according to the compensation weight factor matrix to obtain compensated formation resistivity and formation dielectric constant.

In some exemplary embodiments, the determining a compensation weight factor matrix of button electrode measurement points according to the formation dielectric constant, the formation resistivity and spatial position information of button electrode measurement points of the multi-frequency electrical imaging device comprises:

In some exemplary embodiments, before the extracting formation resistivity, the method further comprises:

step 0, preprocessing the logging data;

In some exemplary embodiments, the well log data comprises impedance values;

for each button electrode measuring point, the following steps are carried out to determine the response space distribution function of each button electrode measuring point:

the step of determining the integral value of the response signal of each button electrode measuring point according to the spatial position information of the button electrode measuring point, the response spatial distribution function of the button electrode measuring point, the formation resistivity and the formation dielectric constant corresponding to the button electrode measuring point comprises the following steps:

taking the button electrode measuring point as the center, selecting 2N +1 rows and 2M +1 columns of button electrode measuring points to form a button electrode measuring array of the button electrode measuring point, wherein N, M are positive integers; calculating a signal detection range of the button electrode according to the spatial position information of the button electrode measuring point, and the formation resistivity and the formation dielectric constant corresponding to the button electrode measuring point, and determining an integral area; integrating the response space distribution function of the button electrode measuring point in the integration area to obtain an integration value of a response signal of the button electrode measuring point;

the step of determining an offset correction matrix of each button electrode measuring point according to the integral value of the response signal of each button electrode measuring point and the area integral values of all adjacent button electrode measuring points in the preset range of each button electrode measuring point comprises the following steps:

replacing the element at the corresponding position in the offset correction matrix of the button electrode by using the ratio of the element in the offset correction matrix of the button electrode measuring point to the central element of the first matrix; replacing a central element in an offset correction matrix of the button electrode measuring point by using the ratio of the integral value of the response signal of the button electrode measuring point to the central element of the first matrix, wherein the replaced offset correction matrix is a compensation coefficient matrix of the button electrode measuring point;

In some exemplary embodiments, the performing, according to the compensation weight factor matrix, signal compensation processing on the formation dielectric constant and the formation resistivity respectively to obtain compensated formation resistivity and formation dielectric constant includes:

respectively taking the ratio of the formation resistivity of each first uniform infinite thick formation model to the calculated impedance value as a scale coefficient of the first uniform infinite thick formation model;

the extracting the stratum dielectric constant from the pre-established dielectric constant-resistivity explanation plate according to the stratum resistivity comprises the following steps:

It can be seen that the measured data compensation method of the multi-frequency electrical imaging device provided by the embodiment of the disclosure can compensate the measured (collected) logging data, and solves the problems that the multi-frequency electrical imaging device is affected by factors such as electrode plate gap, unstable mud resistivity, mud cake covering, coupling of measuring signals of adjacent button electrodes, and the like, so that the focusing effect of the button electrode system is unsatisfactory, the logging data is inaccurate, and further the final image is unclear and the resolution is low in a complex borehole environment, and the accuracy of the obtained logging data is improved.

Example two

The embodiment of the present disclosure provides a method for compensating measurement data of a multi-frequency electrical imaging device, as shown in fig. 2, the method includes:

s1, acquiring logging data of multi-frequency electric imaging equipment;

s2, preprocessing the logging data;

s3, extracting formation resistivity and a formation dielectric constant according to the preprocessed logging data;

s4, determining a compensation weight factor matrix of a button electrode of the multi-frequency electrical imaging equipment according to the formation resistivity and the formation dielectric constant;

and S5, respectively performing signal compensation processing on the dielectric constant and the formation resistivity of the button electrode according to the compensation weight factor matrix to obtain the finally compensated formation resistivity and formation dielectric constant.

In some exemplary embodiments, the multi-frequency electrical imaging apparatus includes a plurality of electrode buttons, and satisfactory logging data is measured by the multi-frequency electrical imaging apparatus. The multi-frequency electrical imaging equipment measures each button electrode to obtain a voltage signal U and a current signal I, and correspondingly obtains logging data, namely an impedance signal R, and the conversion method comprises the following steps:

in some exemplary embodiments, the pre-processing of the well log data comprises: performing one or more of the following treatments: abnormal data detection and elimination, card encountering processing, electric buckle depth correction and data resampling.

In some exemplary embodiments, the anomalous data detection and culling includes: according to the physical fact that the stratum impedance converted by logging data represents the stratum resistivity of a measuring area, identifying and rejecting button electrode data which violate the physical objective rule, wherein the detection process is to identify all button electrode measuring data one by one, the identification rejection condition is that the impedance value corresponding to a measuring signal is 0 or a negative value, the impedance value corresponding to the measuring signal exceeds the button measuring point of the measuring range of an instrument, and the rejection method is to directly delete the measured value of the measuring point;

in some exemplary embodiments, the encounter processing and the electrical buckle depth correction include: and identifying the card encountering condition of the instrument according to the acceleration logging curve, calculating the card encountering distance according to the response value of the acceleration curve, and performing equal-depth translation on the measurement curve to finish card encountering processing and electric buckle depth correction.

In some exemplary embodiments, the data resampling comprises: the logging data are measured at equal time intervals, the data are data with unequal depth intervals, data of certain measuring point positions are lost after abnormal values are removed, in order to deal with the situations, the data are resampled at equal depth intervals, the measured value of the depth corresponding to the sampling point is obtained by utilizing the difference value of the upper point and the lower point adjacent to the depth, and the difference value formula is as follows:

wherein i represents the button electrode number, MD _T Representing the resampled current depth, MD _A Representation and MD _T Adjacent to and less than MD _T Effective measuring point depth of (MD) _B To representAnd MD _T Adjacent and greater than MD _T Effective measuring point depth of (R) _Ti Represents the ith button measured value R of the current measuring point after resampling _Ai Indicating the corresponding measuring point depth MD _A Last ith button measurement value, R _Ai Indicating the corresponding measuring point depth MD _B The ith button measurement. The calculation process is embodied by processing the measured values under the same working frequency; if there are measurement data of a plurality of operating frequencies, the respective calculation is based on the frequencies.

In some exemplary embodiments, step S3 comprises: the method for extracting the formation resistivity by combining impedance signals with different frequencies and extracting the formation dielectric constant by combining multi-frequency signals on the basis of extracting the formation resistivity comprises the following steps:

step S31: establishing a first uniform infinite thick stratum model, wherein parameters in the stratum model are set as: the radius of a borehole is 8.5in, the instrument is centered for measurement, no eccentricity exists, the polar plate is tightly attached to the borehole wall, no gap exists, the relative dielectric constant of the mud and the relative dielectric constant of the stratum are both 10, and the resistivity of the stratum is the same as that of the mud. And synchronously changing the formation resistivity and the mud resistivity in the variation range of 0.2-10000 omega-m and the sampling step length of 0.1 omega-m to form a first formation model sequence with variable resistivity. In some exemplary embodiments, the parameters of the formation model may be set to other values, and the sampling step lengths of the formation resistivity and the mud resistivity may be set to other values, which is not limited to the examples of the present embodiment.

Step S32: calculating the stratum models in the first stratum model sequence one by utilizing a three-dimensional finite element multi-frequency electrical imaging simulation algorithm module, and respectively obtaining equipment responses corresponding to the resistivities, wherein the equipment responses are impedance values; wherein, the simulation algorithm is provided with relevant parameters of the multi-frequency electric imaging equipment.

In some exemplary embodiments, taking the multi-frequency electrical imaging logging instrument MFIT of the midsea oilfield services, ltd as an example, relevant parameters of the logging instrument MFIT are set: three working frequencies (200 KHz, 1MHz and 5 MHz) are adopted, the device consists of six polar plates, 15 button electrodes are distributed on each polar plate in an upper row and a lower row, the distance between a transmitting electrode and a receiving electrode is 8m, and a three-dimensional finite element multi-frequency electrical imaging simulation algorithm is adopted to calculate each stratum model in a first stratum model sequence one by one, so that instrument response impedance values Zb corresponding to different stratum resistivities are obtained, which are also called simulation responses and simulation impedance values; wherein, each stratum model at least respectively obtains the simulation response corresponding to each of the three working frequencies.

Step S33: arranging the calculation results of all the stratum models under different frequencies from small to large according to the impedance values, and taking the ratio of the resistivity value of each stratum model to the calculated impedance value as the scale coefficient of the frequency to obtain a resistivity scale coefficient sequence under the corresponding frequency; the scale coefficient sequence takes the horizontal axis of the impedance value as the ordinate and the scale coefficient as the ordinate, and as shown in fig. 3, each curve represents a scale coefficient curve under different frequencies;

step S34: according to the value of the measured impedance signal of the measuring point, inquiring a scale coefficient sequence under the corresponding frequency to obtain a scale coefficient a corresponding to each measuring point, taking the product of the scale coefficient and the logging response of the measuring point as the resistivity of the measuring point, calibrating the measured impedance signal into a resistivity signal, and selecting the converted resistivity in a segmentation mode according to the applicable resistivity range of different frequencies as the formation resistivity, wherein the value of the measured impedance signal is the impedance value corresponding to the button electrode in the logging data measured by the multi-frequency electrical imaging equipment and is also called the measured impedance value.

In some exemplary embodiments, the segment selection method is as follows:

rt represents the composite formation resistivity obtained by comprehensive multifrequency measurement, R200KHz represents the resistivity under the frequency of 200KHz, R1MHz represents the resistivity under the frequency of 1MHz, and R5MHz represents the resistivity under the frequency of 5 MHz.

Step S35: establishing a second uniform infinite thick stratum model, wherein parameters in the stratum model are set as: the radius of a borehole is 8.5in, the instrument is used for centered measurement, no eccentricity exists, the polar plate is tightly attached to the borehole wall and has no gap, the formation resistivity is the same as the mud resistivity, the variation range is 0.2-10000 omega-m, and the sampling step length is 0.1 omega-m; the dielectric constant of the mud is the same as that of the stratum, the variation range is 1-300, and the sampling step length is 1; and other parameters are unchanged, and the formation resistivity and the formation dielectric constant are circularly changed according to the step length in the change range of the formation resistivity and the formation dielectric constant to form a second formation model sequence. Calculating the stratum models in the second stratum model sequence one by utilizing a three-dimensional finite element multi-frequency electrical imaging simulation algorithm module, wherein the frequency selects a plurality of values (such as 5MHz, 1MHz and 200 KHz), and respectively obtaining equipment responses under a plurality of (such as three) working frequencies corresponding to each resistivity and dielectric constant, wherein the equipment responses are impedance values, also called simulated responses and simulated impedance values; wherein, the simulation algorithm is provided with relevant parameters of the multi-frequency electric imaging equipment. In some exemplary embodiments, the parameters of the formation model may be set to other values, the sampling step lengths of the formation resistivity and the mud resistivity may be set to other values, and the sampling step lengths of the mud dielectric constant and the formation dielectric constant may be set to other values, which is not limited to the examples of the present embodiment.

In some exemplary embodiments, taking the multi-frequency electrical imaging logging instrument MFIT of the midsea oilfield services, ltd as an example, relevant parameters of the logging instrument MFIT are set: three working frequencies (200 KHz, 1MHz and 5 MHz) are adopted, the device is composed of six polar plates, 15 button electrodes are distributed on each polar plate in an upper row and a lower row, and the distance between the transmitting electrode and the receiving electrode is 8m. Simulating (simulating) logging impedance response signals of the MFIT instrument at three working frequencies, changing the dielectric constant by taking the model resistivity as an abscissa and the impedance response signals as an ordinate, and drawing a dielectric constant-resistivity explanation chart as shown in FIG. 4; FIG. 4 is a schematic diagram in which four curves represent different dielectric constant-resistivity interpretation charts.

Step S36: defining a distance function

Where d represents the distance function of the measured response from the library simulated response and i represents the operating frequencyThe rate number, which ranges from 1 to 3, indicates that there are several working frequencies, for example, the logging instrument MFIT has 3 working frequencies, i is 3; y is _i Representing the logging response at the ith operating frequency; r (f) _i And Rt, epsilon) represents the model corresponding simulation response under the ith working frequency, fi represents the working frequency, rt represents the formation resistivity parameter, and epsilon represents the formation dielectric constant parameter.

And traversing the dielectric constant-resistivity explanation chart, and selecting the dielectric constant epsilon corresponding to the minimum distance function value as a stratum dielectric constant extraction value of the measuring point.

In some exemplary embodiments, step S4 includes: determining the influence area of each button electrode measuring point according to the response space distribution of the button electrodes under the condition that the stratum dielectric constant and the stratum resistivity value of the measuring point are taken as background, calculating the signal offset through integrating the surface area of the button electrodes, and forming a compensation weight factor matrix of each measuring point according to the offset and the space position of the button electrodes. Wherein, the influence area refers to the area of the button electrode with response space distribution not 0.

And S3, extracting the corresponding formation resistivity and the formation dielectric constant of the logging data of each measuring point. In some exemplary embodiments, the steps S31, S32, S33, and S35 may be data preparation steps executed in advance, and the resistivity scale coefficient sequence and the dielectric constant-resistivity interpretation chart determined after one execution may be used for extracting the formation resistivity and the formation dielectric constant from all the measurement points.

In some exemplary embodiments, taking the MFIT as an example, the step S4 includes:

step S41: setting structural parameters and three working frequencies (200 KHz, 1MHz and 5 MHz) of a logging instrument MFIT, forming an infinite-thickness stratum model according to the resistivity and the dielectric constant obtained by the composite calculation of the measuring point signals, namely forming the infinite-thickness stratum model according to the stratum resistivity and the stratum dielectric constant of the button electrode measuring point extracted in the step S3, and combining the current borehole parameters of the borehole to be measured, wherein the borehole parameters comprise: the method comprises the following steps of calculating the electrode space potential distribution by using a numerical simulation method according to the borehole radius, the mud resistivity and the mud dielectric constant, and fitting to obtain a three-dimensional space distribution function under a button electrode rectangular coordinate system, namely a response space distribution function, as shown in FIG. 5:

wherein V represents three-dimensional space potential value of rectangular coordinate system, x, y, z represent space position coordinate of rectangular coordinate system, f represents working frequency, D _h Denotes borehole diameter, R _m Represents the mud resistivity, ε _m Denotes the dielectric constant of the slurry, standoff denotes the gap and R _t Representing the formation resistivity, ε _t Representing the formation dielectric constant; wherein x, y, z represent the position coordinates of the button electrode in three-dimensional space of the measuring point integrally formed by the plurality of measuring depth measuring units.

Step S42: for the multi-frequency electrical imaging device well logging data (the number of rows is recorded as NUM, 90 columns per row, NUM is recorded as CNUM), determining the integral value of the response signal of each button electrode measuring point according to the following modes:

taking the current button (assumed as the ith button) electrode measuring point as the center, selecting 2N +1 rows and 2M +1 columns of measuring points to form a button measuring array, as shown in FIG. 6, wherein N, M are all positive integers (in FIG. 6, N = M = 3), converting into a rectangular coordinate system according to the measuring depth (determining a three-dimensional pillar coordinate z value), the polar plate and the position of the button electrode on the polar plate (determining a position angle under the button pillar coordinate), the opening distance of the supporting arm when the polar plate works (a button electrode r value under the pillar coordinate), calculating a button space position, and calculating the formation resistivity and the formation dielectric constant information at the current button electrode measuring point position by using the rectangular coordinate system, and calculating the signal detection range of the current button electrode as an integral area of the current button electrode measuring point, and calculating the distribution function of the button electrode measuring point in the integral area to obtain a response signal integral value (recorded as Sa) of the current button electrode measuring point.

Polling all numbered button electrodes to finish the response signal integral value (recording) of all button electrode measuring pointsIs composed of

Wherein, N represents a row distance in a preset range, M represents a column distance in the preset range, and all adjacent button electrodes in the preset range of one button electrode mean that button electrode measuring points in rows 2n +1 and columns 2m +1 form button electrode measuring points in a button measuring array except the button electrode measuring point itself (central element). N, M is predetermined by production experience, N and M can be equal or not, and are non-negative (special position can be 0, such as measuring point in row 1 or last row), different button electrodes can select the same or different N, M value, but N is not larger than the number of rows of logging data of button, and N is not larger than the total number of rows of measuring data minus the number of rows of button, and is not limited to the example.

Step S43: from the integrated value of the response signal for each button electrode measuring point (CNUM number) (of step S42)

) And the area integral value of all the adjacent button electrode measuring points (2N +1 row 2M +1 column matrix) in the preset range of each button electrode measuring point (CNUM), determining an offset correction matrix of each button electrode measuring point, comprising:

calculating the integral value of the spatial distribution function of the button electrode measuring points in each button measuring array (2N +1 row 2M +1 column matrix) at the electrode surface area of the current button electrode measuring point (i.e. the integral area described in step S42)

Forming a first matrix (marked as matrix) according to the spatial row and column arrangement sequence of the button electrode measuring points

) For the first matrix

The middle elements take the inverse number to form an offset correction matrix (recorded as a matrix) of each button electrode measuring point

)；

Step S44: correcting matrix according to integral value and offset of response signal of each button electrode measuring point (CNUM pieces in total)

Determining compensation weight factor matrix of each button electrode measuring point

The method comprises the following steps:

correcting the offset of each button electrode measurement point by (

Row 2m +1 column matrix) and its first matrix

The ratio of the central element replaces the corresponding offset correction matrix

Correcting the offset by the matrix according to the element value corresponding to the original position

Center value is calculated by the integrated response signal integral value of the button electrode measuring point calculated in step S42

And a first matrix

Center element ratio replacement, correcting the offset by matrix

Is converted intoCompensation coefficient matrix (A) of button electrode measuring point ⁱ )；

Step S45: and (3) carrying out normalization processing on the compensation coefficient matrix of each button electrode measuring point:

for example, for button electrode station number i (CNUM button electrode stations)

A ⁱ In order to normalize the pre-compensation coefficient matrix,

the compensation coefficient matrix is normalized, i represents all measuring point numbers, CNUM represents the total number of measuring points of the button electrode, N, M represents the number of left and right points and the number of upper and lower points of a central button measuring point, and k and j represent the row subscript and column subscript of the matrix.

And converting the synthesized compensation coefficient matrix of the button electrode measuring point into a final compensation weight factor matrix of the button electrode measuring point through normalization.

In step S4, for each measurement point, a compensation weight factor matrix corresponding to the measurement point is determined.

In some exemplary embodiments, step S5 includes: the formation resistivity and the formation dielectric constant after compensation of the button electrode measuring points are determined by the following method aiming at the button electrode measuring points of the multi-frequency electric imaging equipment, and the method comprises the following steps:

step S51: for each electrode button electrode measurement point, the following steps are performed: the compensation weight factor matrix of the button electrode measuring point

Forming a resistivity matrix R and a dielectric constant matrix E with the corresponding button electrode measuring point array for inner product to form a new formation resistivity compensation matrix R _δ And formation dielectric constant compensation quantity matrix E _δ ：

Compensation matrix R for formation resistivity _δ And formation dielectric constant compensation quantity matrix E _δ Summing all elements to obtain the formation resistivity value after compensation of the central element

And formation permittivity values

Where i, j denote subscripts of the elements in the matrix, R _δij Matrix R representing resistivity compensation quantity _δ I row and j column elements of (1), E _δij Matrix E representing the compensation quantity of relative permittivity _δ Row i and column j.

Step S52: and processing all button electrode measuring points obtained by one-time measurement of the multi-frequency electric imaging equipment point by point to obtain the formation resistivity and the formation dielectric constant after dynamic compensation of all logging data.

Step S5, the formation resistivity and the formation dielectric constant after final compensation are respectively obtained for each measuring point.

In some exemplary embodiments, the method further comprises:

step S6: formatting output and displaying images: the compensated data is imaged by means of a data imaging and drawing function of a commercial software Techlog platform, and the image definition before and after processing is compared with that of a figure 7.

In some exemplary embodiments, before step S6, the method further comprises:

s06, carrying out equalization processing on the compensated data;

in some exemplary embodiments, the equalization process includes: taking data of a fixed window length, wherein the window length comprises H measuring points, and calculating the resistivity average value R of all measuring points of 90 button electrodes in the window length _H×90 Simultaneously calculating the average value R of H measuring points of each button in the window length _Hi After equalization, the measured point resistivity is:

R _ij ′R _ij +R _H×90 -R _Hj j＝1，2，3，…90；i＝1，2，…，H

wherein:

wherein: i represents a measuring point depth change number, j represents a measuring button number, R _ij Resistivity, R, was measured for the jth button electrode on depth number i _Hj Mean value of j measured resistivity values of buttons representing H sampling points of window length, R _H×90 Mean value of measured resistivity values, R, of all buttons representing H sampling points of window length _ij ' represents the equalized value.

And (6) executing the step S6 according to the balanced measuring point resistivity and the stratum dielectric constant compensated in the step S5 to obtain an imaging result.

It can be seen that the beneficial effects of the scheme of the embodiment of the present disclosure include: the method has the advantages that the signal detection performance and the environment influence characteristic difference along with the frequency change are considered, the stratum parameters are extracted by utilizing the multi-frequency data combination, the comprehensive compensation and correction are carried out on the coupling influence between the environmental noise and the button electrodes according to the dynamic change of the stratum background parameters, the electrode button focusing effect is improved, the interference of non-stratum factors to signals is weakened and eliminated, and the resolution of an imaging image definition instrument is improved.

EXAMPLE III

The embodiment of the present disclosure provides a measurement data compensation apparatus 30 of a multi-frequency electrical imaging device, including:

the extraction module 301 is configured to determine formation resistivity according to logging data obtained by measurement of the multi-frequency electrical imaging device, and determine a formation dielectric constant according to the formation resistivity;

the compensation matrix determining module 302 is configured to determine a compensation weight factor matrix of a button electrode measuring point according to the formation dielectric constant, the formation resistivity and spatial position information of the button electrode measuring point of the multi-frequency electrical imaging device;

and the compensation module 303 is configured to perform signal compensation processing on the formation dielectric constant and the formation resistivity respectively according to the compensation weight factor matrix to obtain the compensated formation resistivity and the formation dielectric constant.

In some exemplary embodiments, the compensation matrix determination module 302 is configured to,

determining an integral value of a response signal of each button electrode measuring point according to the spatial position information of the button electrode measuring point, the response spatial distribution function of the button electrode measuring point, the formation resistivity and the formation dielectric constant corresponding to the button electrode measuring point;

In some exemplary embodiments, the apparatus further comprises a preprocessing module configured to preprocess the well log data;

wherein the pretreatment comprises at least one of the following treatments: abnormal data detection and elimination, card processing, electric buckle depth correction and data resampling.

In some exemplary embodiments, the well log data comprises impedance values;

the extraction module 301 is configured to extract the formation resistivity from a pre-established resistivity scale coefficient sequence according to the impedance value and the corresponding working frequency in the logging data; and extracting the stratum dielectric constant from the pre-established dielectric constant-resistivity explanation plate library according to the stratum resistivity.

In some exemplary embodiments, the compensation matrix determination module 302 is further configured to, for each button electrode measurement point, determine the response spatial distribution function for each button electrode measurement point by:

the compensation matrix determination module 302 is further configured to determine, for each button electrode measurement point of the multi-frequency electrical imaging device, an integrated value of the response signal of the button electrode measurement point according to the following manner:

taking the button electrode measuring point as the center, selecting the button electrode measuring points 2N +1 rows and 2M +1 columns to form a button electrode measuring array of the button electrode measuring point, wherein N, M are positive integers; calculating the signal detection range of the button electrode according to the spatial position information of the button electrode measuring point, and the formation resistivity and the formation dielectric constant corresponding to the button electrode measuring point, and determining an integral area; integrating the response space distribution function of the button electrode measuring point in the integration area to obtain an integration value of the response signal of the button electrode measuring point;

the compensation matrix determination module 302 is further configured to determine, for each button electrode measurement point of the multi-frequency electrical imaging apparatus, an offset correction matrix for the button electrode measurement point according to the following manner:

according to the adjacent button electrode measuring points in the button electrode measuring array of the button electrode measuring points, calculating the integral value of the response space distribution function of each adjacent button electrode measuring point in the integral area of the button electrode measuring point one by one; according to the spatial row-column positions of button electrode measuring points in the button electrode measuring array of the button electrode measuring points, forming a first matrix by the integral values of all the adjacent button electrode measuring points obtained by arrangement calculation and the integral values of the response signals of the central button electrode measuring point, and taking the inverse numbers of the elements in the first matrix to form an offset correction matrix of each button electrode measuring point;

the compensation matrix determination module 302 is further configured to, for each button electrode measurement point of the multi-frequency electrical imaging apparatus, determine a compensation weight factor matrix of the button electrode measurement point according to the following manner:

In some exemplary embodiments, the compensation module 303 is configured to determine the compensated formation resistivity and the formation dielectric constant of each button electrode measuring point of the multi-frequency electrical imaging device by performing the following method for each button electrode measuring point:

An embodiment of the present disclosure further provides an electronic apparatus, including a memory and a processor, where the memory stores a computer program, and the processor is configured to run the computer program to perform the measurement data compensation method of the multi-frequency electrical imaging device in any of the above embodiments.

The embodiment of the present disclosure also provides a storage medium, in which a computer program is stored, where the computer program is configured to execute the measurement data compensation method of the multi-frequency electrical imaging apparatus in any one of the above embodiments when running.

It will be understood by those of ordinary skill in the art that all or some of the steps of the methods, systems, functional modules/units in the devices disclosed above may be implemented as software, firmware, hardware, and suitable combinations thereof. In a hardware implementation, the division between functional modules/units mentioned in the above description does not necessarily correspond to the division of physical components; for example, one physical component may have multiple functions, or one function or step may be performed by several physical components in cooperation. Some or all of the components may be implemented as software executed by a processor, such as a digital signal processor or microprocessor, or as hardware, or as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on computer readable media, which may include computer storage media (or non-transitory media) and communication media (or transitory media). The term computer storage media includes volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data, as is well known to those skilled in the art. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital Versatile Disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can accessed by a computer. In addition, communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media as known to those skilled in the art.

Claims

1. A method for compensating measured data of a multi-frequency electrical imaging device, comprising,

respectively performing signal compensation processing on the formation dielectric constant and the formation resistivity according to the compensation weight factor matrix to obtain compensated formation resistivity and formation dielectric constant;

the determining of the compensation weight factor matrix of the button electrode measuring points according to the formation dielectric constant, the formation resistivity and the spatial position information of the button electrode measuring points of the multi-frequency electrical imaging device comprises:

determining a compensation weight factor matrix of each button electrode measuring point according to the integral value and the offset correction matrix of the response signal of each button electrode measuring point;

the respectively performing signal compensation processing on the formation dielectric constant and the formation resistivity according to the compensation weight factor matrix to obtain the compensated formation resistivity and the formation dielectric constant, and the method comprises the following steps:

2. The method of claim 1,

prior to the determining the formation resistivity, the method further comprises:

preprocessing the logging data; the pretreatment at least comprises one of the following treatments:

abnormal data detection and elimination, card processing, electric buckle depth correction and data resampling.

3. The method according to claim 1 or 2,

the well log data comprises impedance values;

4. The method of claim 1,

the determining the response space distribution function of the button electrode measuring point of the multi-frequency electrical imaging device according to the stratum dielectric constant and the stratum resistivity comprises the following steps:

calculating the integral value of the response space distribution function of each adjacent button electrode measuring point in the integral area of the button electrode measuring point one by one according to the adjacent button electrode measuring points in the button electrode measuring array of the button electrode measuring point; according to the spatial row-column positions of button electrode measuring points in the button electrode measuring array of the button electrode measuring points, forming a first matrix by the integral values of all the adjacent button electrode measuring points obtained by arrangement calculation and the integral values of the response signals of the central button electrode measuring point, and taking the inverse numbers of the elements in the first matrix to form an offset correction matrix of each button electrode measuring point;

for each button electrode measuring point of the multi-frequency electric imaging equipment, determining a compensation weight factor matrix of the button electrode measuring point according to the following modes:

5. The method of claim 3,

the resistivity scale factor sequence is established according to the following manner:

and according to the impedance value of the button electrode measuring point, inquiring the resistivity scale coefficient sequence under the corresponding working frequency to obtain the corresponding scale coefficient, calibrating the impedance value into the resistivity by taking the product of the scale coefficient and the impedance value as the resistivity, and sectionally selecting the calibrated resistivity according to the applicable resistivity range of different frequencies as the formation resistivity of the button electrode measuring point.

6. The method of claim 3,

the dielectric constant-resistivity interpretation plate was created according to the following manner:

7. An electronic device comprising a memory and a processor, wherein the memory has stored therein a computer program, and wherein the processor is arranged to execute the computer program to perform the method of any of claims 1 to 6.

8. A storage medium, in which a computer program is stored, wherein the computer program is arranged to perform the method of any of claims 1 to 6 when executed.