CA3194763A1

CA3194763A1 - Azimuthal electromagnetic wave logging while drilling signal processing method and apparatus, and storage medium

Info

Publication number: CA3194763A1
Application number: CA3194763A
Authority: CA
Inventors: Tianlin LIU; Xizhou YUE; Mingxue MA; Guoyu LI; Jinhai ZHAI; Xinhuo WENG
Original assignee: China Oilfield Services Ltd
Current assignee: China Oilfield Services Ltd
Priority date: 2020-11-26
Filing date: 2021-07-14
Publication date: 2022-06-02
Also published as: WO2022110832A1; CN112487355A; CN112487355B

Abstract

An azimuthal electromagnetic wave logging while drilling signal processing method and apparatus, and a storage medium. The method comprises: obtaining a logging signal collected by an azimuthal electromagnetic wave logging while drilling device; determining a fitting parameter of the logging signal by taking a trigonometric function as a basis function according to an orthogonal function theory; and determining, according to the fitting parameter, stratum information corresponding to the logging signal, the stratum information at least comprising one of the following: a phase geological signal, an amplitude geological signal, a phase anisotropic signal, and an amplitude anisotropic signal. The azimuthal electromagnetic wave logging while drilling device is a double-oblique coil device.

Description

Azimuthal Electromagnetic Wave Logging while Drilling Signal Processing Method and Apparatus, and Storage Medium Technical Field The present disclosure relates to but is not limited to the field of petroleum exploration and development, belonging to an electric logging method domain, in particular to a method for processing an azimuth electromagnetic wave logging while drilling signal, an apparatus, and a storage medium.
Background Azimuth electromagnetic wave logging while drilling may provide stratum azimuth information, and is widely applied in geological orientation in high angle wells (HA)/horizontal wells (HZ) and stratum evaluation while drilling. Its azimuth information mainly comes from a structure of an axial orthogonal coil, a single-tilted coil, or a double-tilted coil of an azimuth electromagnetic wave logging while drilling instrument. When the instrument rotates for one cycle, measured signals of the structures of the axial orthogonal coil and the single-tilted coil may be expressed by a first-order trigonometric function (three parameters), measured signals of the structure of the double-tilted coil may be expressed by a second-order trigonometric function (five parameters), and azimuth signals, anisotropic signals, and the like may be obtained by processing related parameters of functions. Therefore, accurately fitting measured signals of azimuth electromagnetic wave logging while drilling and extracting related parameters are critical for acquiring stratum information.
At present, fitting methods for measured signals of the structures of the axial orthogonal coil and the single-tilted coil of the electromagnetic wave logging while drilling instrument have had related industry standards, such as IEEE Std 1057. However, due to a novel structure Date recite/Date received 2023-03-10 of the double-tilted coil system of the azimuth electromagnetic wave logging while drilling instrument, fitting methods of its measured signals have not been disclosed.
Due to multiple measurements by the instrument in a single period and sampling errors, if a simple undetermined coefficient method is used to solve parameters to be fitted, multiple solution results will occur. If an iterative approximation method is used to solve the parameters to be fitted, errors may be reduced, but its time and space complexity are relatively high.
Summary The following is a summary of the subject matter described in detail herein.
This summary is not intended to limit the protection scope of the claims.
An embodiment of the present disclosure provides a method for processing an azimuth electromagnetic wave logging while drilling signal, an apparatus, and a storage medium, which can achieve an extraction of a geological signal, an anisotropic signal, and the like of a double-tilted coil system of azimuth electromagnetic wave logging while drilling.
An embodiment of the present disclosure provides a method for processing an azimuth electromagnetic wave logging while drilling signal, including, acquiring a logging signal collected by an azimuth electromagnetic wave logging while drilling device;
determining a fitting parameter of the logging signal by taking a trigonometric function as a basis function according to an orthogonal function theory; and determining stratum information corresponding to the logging signal according to the fitting parameter, wherein the stratum information at least includes one of the following: a phase geological signal, an amplitude geological signal, a phase anisotropic signal, and an amplitude anisotropic signal; wherein, the azimuth electromagnetic wave logging while drilling device is a device with a double-tilted coil system.
In some exemplary embodiments, the logging signal includes: sector measuring signals collected by rotating the double-tilted coil system of the azimuth electromagnetic wave logging

2 Date recite/Date received 2023-03-10 while drilling device for one cycle according to a preset quantity of sampling times; and a waveform of a sector measuring signal is a second-order trigonometric function waveform with the following characteristics:
f (xo) = ao + al cos xn + a2 sin xn +a3 cos 2x77 +a4 sin 2x77 = f (x ) = x = a a a a wherein, n is the sector measuring signal, n is a sector angle, 0, 1, 2, 3, and a4 are fitting parameters.
In some exemplary embodiments, determining the fitting parameter of the logging signal by taking the trigonometric function as the basis function according to the orthogonal function theory includes: judging whether the logging signal is sampled uniformly; when the logging signal is sampled uniformly, according to the orthogonal function theory, by taking the trigonometric function as the basis function, determining the fitting parameter of the logging signal by adopting a preset uniform sampling signal fitting algorithm; and when the logging signal is not sampled uniformly, performing filling for an empty sector of the logging signal, and for the filled signal, according to the orthogonal function theory, by taking the trigonometric function as the basis function, determining the fitting parameter of the logging signal by adopting a preset uniform sampling signal fitting algorithm; or, according to the orthogonal function theory, by taking the trigonometric function as the basis function, determining the fitting parameter of the logging signal by adopting a preset non-uniform sampling signal fitting algorithm.
In some exemplary embodiments, according to the orthogonal function theory, by taking the trigonometric function as the basis function, determining the fitting parameter of the logging signal by adopting the preset non-uniform sampling signal fitting algorithm includes:
performing an accumulative summation on the logging signal, multiplying the logging signal with a preset trigonometric function and then performing an accumulative summation, and multiplying two preset trigonometric functions and performing an accumulative summation;
determining a fitting matrix and a first fitting vector according to results of all cumulative

3 Date recite/Date received 2023-03-10 summations; wherein the preset trigonometric function is one or more of the following functions: cos xn, sin xn, cos 2xn, and sin 2xn; correspondingly, a result of the cumulative summation after multiplying the logging signal with the preset trigonometric function is one or more; and determining the fitting parameter according to the fitting matrix and the first fitting vector.
In some exemplary embodiments, according to the orthogonal function theory, by taking the trigonometric function as the basis function, determining the fitting parameter of the logging signal by adopting the preset uniform sampling signal fitting algorithm includes: performing an average operation on the logging signal to obtain an average value, multiplying the logging signal with a preset trigonometric function and then performing an accumulative summation, performing an accumulative summation on a square of a preset trigonometric function;
determining a second fitting vector according to the average value and results of all an accumulative summations; wherein the preset trigonometric function is one or more of the following functions: cos xn, sin xn, cos 2xn, and sin 2xn; correspondingly, a result of the cumulative summation after multiplying the logging signal with the preset trigonometric function is one or more; and determining the fitting parameter according to the second fitting vector.
In some exemplary embodiments, a structure of the double-tilted coil system includes:
transmitting and receiving coils which are not along an axial direction of an instrument, but form a certain included angle with the axial direction respectively; wherein the axial direction of the instrument includes three axial directions of a three-dimensional rectangular coordinate system.
In some exemplary embodiments, performing filling for the empty sector of the logging signal includes: for each empty sector, performing filling according to one of the following modes: determining filling data according to logging signals of sectors at two sides of the empty sector, and filling the empty sector with the determined filling data; and filling the empty sector

4 Date recite/Date received 2023-03-10 according to a corresponding logging signal of the empty sector in a previous measuring period.
In some exemplary embodiments, the waveform of the sector measuring signal further has the following characteristics:
f (xn) = bo + blcos(x, + col) + b2 cos(2xn+co2) wherein, b , , bl b2, CI, and C 2 meet the following relationships: b =a 0 , bi cos q = a, k sin q = ¨a2 b2 cos 02= a, , and b2 sin (6,2 = ¨a, , , .
An embodiment of the present disclosure further provides an electronic apparatus, including a memory and a processor, wherein the memory stores a computer program for processing an azimuth electromagnetic wave logging while drilling signal, and the processor is configured to read and run the computer program for processing the azimuth electromagnetic wave logging while drilling signal to execute any of the above methods for processing the azimuth electromagnetic wave logging while drilling signal.
An embodiment of the present disclosure further provides a storage medium, in which a computer program is stored, wherein the computer program is configured to perform any of the above methods for processing the azimuth electromagnetic wave logging while drilling signal when being run.
Other aspects will become apparent after reading and understanding the drawings and detailed description.
Brief Description of Drawings FIG. 1 is a schematic diagram of a structure of a double-tilted coil system in an embodiment of the present disclosure.
FIG. 2 is a flowchart of a method for processing an azimuth electromagnetic wave logging while drilling signal in an embodiment of the present disclosure.
FIG. 3 is a schematic diagram of theory and fitted signals of azimuth electromagnetic

5 Date recite/Date received 2023-03-10 wave logging while drilling in a single period in an embodiment of the present disclosure.
FIG. 4 is a schematic diagram of a signal containing noise and a fitted signal of azimuth electromagnetic wave logging while drilling in a single period in an embodiment of the present disclosure.
FIG. 5 is a schematic diagram of amplitudes of actually measured and fitted signals in an embodiment of the present disclosure.
FIG. 6 is a schematic diagram of phases of actually measured and fitted signals in an embodiment of the present disclosure.
FIG. 7 is a schematic diagram of an amplitude geological signal in an embodiment of the .. present disclosure.
FIG. 8 is a schematic diagram of a phase geological signal in an embodiment of the present disclosure.
FIG. 9 is a schematic diagram of an amplitude anisotropic signal in an embodiment of the present disclosure.
FIG. 10 is a schematic diagram of a phase anisotropic signal in an embodiment of the present disclosure.
FIG. 11 is a diagram of a structure of an apparatus for processing azimuth electromagnetic wave logging while drilling signal in an embodiment of the present disclosure.
FIG. 12 is a flowchart of another method for processing an azimuth electromagnetic wave logging while drilling signal in an embodiment of the present disclosure.
FIG. 13 is a diagram of a structure of another apparatus for processing an azimuth electromagnetic wave logging while drilling signal in an embodiment of the present disclosure.

6 Date recite/Date received 2023-03-10 Detailed Description In order to make the purpose, technical solutions, and advantages of the present document clearer, a further detailed description of the present document will be given below in conjunction with the accompanying drawings and embodiments. The embodiments in the present application and the features in the embodiments may be combined with each other arbitrarily if there is no conflict.
Numbers of the following acts do not define a particular execution sequence, and the execution sequence can be adjusted for part of acts according to the embodiments.
An embodiment of the present disclosure provides a method for processing an azimuth electromagnetic wave logging while drilling signal. In conjunction with FIG.
1, in a coil system, a transmitting coil forms an arbitrary included angle (not along an axial direction) with an axial direction of an instrument (x axis, y axis, z axis), and a receiving coil also forms an arbitrary included angle (not along the axial direction) with the axial direction of the instrument. In some exemplary embodiments, for coil systems Ti -R3 and T2-R4 described in a typical example, such as the patent entitled "Multicomponent Azimuth Electromagnetic Wave Resistivity Imaging While Drilling Instrument" (CN104929622A), the transmitting and receiving coils form -45 degrees and 45 degrees with an axial direction of a drill collar, respectively.
A method for processing an azimuth electromagnetic wave logging while drilling signal, as shown in FIG. 2, includes the following acts.
In act sl, a sector measuring signal f (xn) and a sector angle n when a double-tilted coil system of an azimuth electromagnetic wave logging while drilling instrument rotates for one cycle, are inputted. As shown by a solid line waveform in FIG. 3, the waveform is represented as:
f (xn) = a() +a1 cos xn +a7 sin; +a, cos 2x, +a4 sin 2x, (1) wherein, a a, a2 a, õ
õ and a4 are parameters to be fitted, that is, fitting parameters,

7 Date recite/Date received 2023-03-10 which are related to an electromagnetic field component.
In act s2, whether a logging signal is uniformly sampled is judged, if the logging signal is not sampled uniformly, the act s3 or s4 is performed; and if the logging signal is sampled uniformly, the act s5 is performed. In the present embodiment, the logging signal is sampled uniformly, so the act s5 is performed.
In act s6, according to a fitting parameter determined in the act s5, stratum information corresponding to the logging signal is determined; the stratum information at least includes one of the following: a phase geological signal, an amplitude geological signal, a phase anisotropic signal, and an amplitude anisotropic signal.
Herein when the logging signal is determined to not be the uniformly sampled signal, two solutions may be selected: 1. after the act S3 is performed to fill an empty sector, the act s5 is performed; and 2. the act s4 is performed, that is, the fitting parameter is determined by adopting a preset non-uniform sampling signal fitting algorithm, and then the act s6 is performed.
In some exemplary embodiments, whether the logging signal is the uniformly sampled signal is judged, which includes: if there is a null value in a sector, it is determined that the sampled signal is not uniform; and if there is no null value, it is determined that the sampled signal is uniform. Usually, preset sector angles of an logging while drilling instrument are uniform, so as long as a sector of each measured point is filled, it is regarded as uniform sampling, otherwise non-uniform sampling.
In some exemplary embodiments, the act s4 may include: according to an orthogonal function theory, by taking a trigonometric function as a basis function, obtaining a fitting parameter of the non-uniformly sampled signal. According to the orthogonal function theory, it may refer to that: performing processing based on a calculation formula designed according to the orthogonal function theory.
In some exemplary embodiments, the act s4 may include the following acts s4.1 to s4.7.

8 Date recite/Date received 2023-03-10 In the act s4.1, an accumulative summation is performed on the logging signal, then a left f(x) side of formula (1) may be written as n=1 , a right side thereof may be written as:
+ allcos xn +a2sinxn + a31 cos 2xn + a4 sin 2xn n=1 n=1 n=1 n=1 n=1 (2) In the act s4.2, an accumulative summation is performed on a product of multiplying the logging signal with a trigonometric function COS.;
then the left side of formula (1) is f (xn) cos xi, n=1 , and the right side thereof may be written as:
Ea, cos xn + E cos2 xn a2 Leos xn sin xn + a,Ecos xn cos 2xn + a4Ecos xn sin 2xn n=1 n=1 n=1 n=1 n=1 (3) In the act s4.3, an accumulative summation is performed on a product of multiplying the , logging signal with a trigonometric function sin; then the left side of formula (1) is f (xn) sin xn n=1 , and the right side thereof may be written as:
a, sin; + alIcos xn sin; + a2Isin2 xn + a3 sin xn cos 2x + a4sin ; sin 2;
n=1 n=1 n=1 n=1 n=1 (4) In the act s4.4, an accumulative summation is performed on a product of multiplying the logging signal with a trigonometric function cos2x , then the left side of formula (1) is f (xn) cos 2xn n=1 , and the right side thereof may be written as:
E, cos 2; + E cos; cos 2; + a2 E sin ; cos 2; + a, Ecos2 + a4 E cos 2; sin 2;
n=1 n=1 n=1 n=1 n=1 (5) In the act s4.5, an accumulative summation is performed on a product of multiplying the logging signal with a trigonometric function sin2x , then the left side of formula (1) is f(x) sin 2;
n=1 , and the right side thereof may be written as:

9 Date recite/Date received 2023-03-10 N N N N N
Eao sin 2xõ + a, Ecos xn sin 2xõ + a2 E sin xn sin 2xõ + a, E cos 2xõ sin 2xõ
+ a, E sin2 2xõ
n=1 n=1 n=1 n=1 n=1 (6) Herein, a value of N represents a quantity of sampling values in each fitting, that is, a quantity of input values in a single fitting. For uniform sampling (without a null value), the value of N is equal to a quantity of sampling points in one period, and for non-uniform sampling (with the null value), the value of N is equal to a quantity of sampling points in one period minus a quantity of null values. In the act S4, the value of N is equal to the quantity of sampling points in one period minus the quantity of null values.
ao al a2 , a a In the act s4.6, parameters to be fitted , , l3, and fi 4 are calculated. Taking the following formulas:
N N
Nc1 ICOS Xn Ns1 = I sin xn n=1 , n=1 (7) N N
N21 1 cos 2xn N2 s 1 = I sin 2xn n=1 n=1 (8) , N N
N fc =If (x n) cos x n N f, =If (x n) sin Xn n=1 n=1 (9) , N N
N f 2c 1f(x)cos 2xn Nf2s I f( n X ) sin 2xn n=1 , n=1 (10) N N N
Nc2 1 COS2 xi, Ns2 = 1 sin2 xn Ncs = I sin xn cos xn n=1 n=1 n=1 (11) , , N N N
N22 Icos2 2xn N22 = 1 sin2 2xn N2c2s = 1 cos 2xn sin 2xn n=1 n=1 n=1 (12) , , N N
N2 cs 1 cos 2x sin Xn N2sc =ICOS Xn sin 2x n=1 , n=1 (13) N N
N2 ss I sin xn sin 2; N2cc =1 cos xncos2xn n=1 , n=1 (14) A = ¨If (x ) Ac = Icosxn As = ¨I sin xn f N n 1 n (15) Date recite/Date received 2023-03-10 N N
4 = ¨11 cos 2xõ 48 = ¨1I sin 2x,, c N n-i N n-i (16) , The following formula may be obtained:
- a - - 1 --1-A28 Af 0 4 A8 A2 c al Nci Nc2 Ncs N 2 cc N25 Nfc a2 = /Vs, /Vcs Ns2 N2 cs N, N
fs a3 1'T2c 1'T2cc 1'T2 CS N2 c2 1'T2c28 Nf 2c a4 - N28 N28c N288 N2c25 N282 _ _ Nf 28 _ (17) - -That is, a fitting parameter A [ a , a' , a2 , a3, a41 is determined according to a fitting matrix T and a first fitting vector M; wherein the fitting matrix T is -1 Ac A8 4C 48 N Cl N C2 N CS N2 cc N2 SC
NS1 N CS N 8 2 1'T2cs N2 ss ;
N2 c N2 cc N2 cs N2 c 2 N2 as _N28 1'T28c N288 N2 c28 N282 _ The first fitting vector M is -Af N fc N
fY -Nf 2c _Nf 2 s _ Thereby, the fitting parameter A = T-1 M.
In some exemplary embodiments, the act s4 further includes the act s4.7 to obtain a fitted signal; and after the act s4.7, the act s6 is performed.
In some exemplary embodiments, the act s4.7 includes: after a corresponding fitting formula is obtained according to the fitting parameter, a sector angle is brought into the fitting formula (such as formula (1)), and a fitted waveform is obtained by calculating, and is called the fitted signal. A purpose of calculating and retaining the fitted signal here is to compare and Date recite/Date received 2023-03-10 test a fitting effect in an actual data processing process, and to provide a guidance for a cause analysis of sampling errors, null values, and the like.
In some exemplary embodiments, the act s6 is no longer performed when the fitted signal is a signal of a single period.
In some exemplary embodiments, in the act s5, according to an orthogonal function theory, by taking a trigonometric function as a basis function, obtaining a fitting parameter of the uniformly sampled signal, includes the following acts s5.1 to s5.8.

Af = f (xn ) In the act s5.1, the logging signal is averaged to obtain Nn=1 In the act s5.2, an accumulative summation is performed on a product of multiplying the Nic f(x n) cos xn cos x logging signal with a trigonometric function n to obtain n=1 In the act s5.3, an accumulative summation is performed on a product of multiplying the N fs = f (xn) sin x77 logging signal with a trigonometric function sin xn to obtain n=1 In the act s5.4, an accumulative summation is performed on a product of multiplying the Nf2c = f(Xn )COS 2x n logging signal with a trigonometric function cos 2xn to obtain n=1 In the act s5.5, an accumulative summation is performed on a product of multiplying the logging signal with a trigonometric function sin2xõ to obtain N12 s f (xn) sin .
n=1 Nc2 COS2 x Ns2 sin2 xn In the act s5.6, square terms are calculated: n=1 n=1 N2c2 ICOS2 2x77 N2s2 sin2 2x77 n=1 , and n=1 Herein, a value of N represents a quantity of sampling values in each fitting, that is, a quantity of input values in a single fitting. For uniform sampling (without a null value), the value of N is equal to a quantity of sampling points in one period, and for non-uniform sampling Date recite/Date received 2023-03-10 (with the null value), the value of N is equal to a quantity of sampling points in one period minus a quantity of null values. In the act S5, the value of N is equal to the quantity of sampling points in one period.
In some exemplary embodiments, the act s5.6 further includes: determining a second fitting vector Q [ApNfc, Nfs, Nf2c, Nf2s, Ara, Ns2, N2c.2, N2s2].
Nic N
fs a A cli= N a2 =
N
In the act s5.7, parameters to be fitted are obtained: = f, c2 , s2 , N12c N12 s a3 = a4 =
N2 c2 and N2 s 2 , .
In some exemplary embodiments, the act s5 further includes act s5.8, i.e., a fitted signal corresponding to the fitting parameter is obtained, and after the act s5.8, the act s6 is performed.
In some exemplary embodiments, the act s5.8 includes: after a corresponding fitting formula is obtained according to the fitting parameter, a sector angle is brought into the fitting formula (such as formula (1)), and a fitted waveform is obtained by calculating, and is called the fitted signal. A purpose of calculating and retaining the fitted signal here is to compare and test a fitting effect in an actual data processing process, and to provide a guidance for a cause analysis of sampling errors, null values, and the like.
In some exemplary embodiments, the obtained fitted signal is shown as a dotted line waveform in FIG. 4.
In some exemplary embodiments, the act s6 is no longer performed when the fitted signal is a signal of a single period.
In some exemplary embodiments, a signal containing noise, such as a solid line waveform in FIG. 5, is processed by the same acts, and a fitted signal, such as a dotted line waveform in FIG. 5, may be obtained. It is easy to see that the method has an excellent suppression effect on noise.

Date recite/Date received 2023-03-10 In some exemplary embodiments, the act s6 includes: a geological signal and an anisotropic signal are calculated according to the following:
a phase geological signal: GP = arctan ao+a3+ai. ' (18) ao+a3¨a1 an amplitude geological signal: GA = ¨20/og10 ao+a3+cti* ' (19) ao+a3¨a1 a phase anisotropic signal: MP = arctan a 4-a3+al* (20) a0¨a3+a2' an amplitude anisotropic signal: MA = ¨20/ogio ao+a3+ai. (21) cto¨a3+a2 In some exemplary embodiments, the act s3 includes one of the following modes.
A first solution is an interpolation approach, that is, for each empty sector, by using logging signal data of sectors at two sides of the empty sector, the empty sector is filled by the interpolation approach.
A second solution is an inheritance approach, that is, for each empty sector, a logging signal of the current empty sector is filled by a logging signal of the sector in a previous period by using last rotation measuring data (a logging signal of the empty sector in a previous measuring period), that is, a null value of the sector in the present period is filled by a measured value in the previous period in an inheritance approach.
In some exemplary embodiments, a structure of the double-tilted coil system of the azimuth electromagnetic wave logging while drilling instrument is that:
transmitting and receiving coils are not along an axis direction of an instrument (x axis, y axis, z axis), but they form a certain included angle with the axis direction respectively.
In some exemplary embodiments, the measuring signal waveform of the structure of the double-tilted coil system in the act sl may be: a second-order trigonometric function waveform, such as formula (1), or its mathematical variant, such as:
f (x) = bo +b1 cos(x, + col) + b2 cos(41+co2) (22) Herein, parameters b , b1 , b2, g, and C2 and the fitting parameters in formula (1) a al a2 , and a4 have the following relationships: b a , b1cosq =

Date recue/Date received 2023-03-10 bi sin q = ¨a2 b2 cos co2 = d a an 3 , b2 sin go2 = ¨a, , .
Accordingly, according to the above relationships between the parameters described above and according to the acts s2 to s5, the technical personnel in the field correspondingly carry out an equivalent deformation, perform fitting to obtain the parameters a , al , a2, a3, and a4, and after that, the parameters b , b1 , b2 , g , and C 2 are further determined. Other signals may still be determined correspondingly according to the act s6.
The method for processing an azimuth electromagnetic wave logging while drilling signal according to the embodiment of the present disclosure may be performed by a computer.
An embodiment of the present disclosure further provides an apparatus for processing an azimuth electromagnetic wave logging while drilling signal, as shown in FIG.
11, including: a signal input and output unit, configured to input an original signal (i.e. an original logging signal generated by the azimuth electromagnetic wave logging while drilling instrument) and output a fitted signal; a sampling unit, configured to perform signal sampling; a storage unit, configured to store a constant and a variable in a solution process; and a calculating unit, configured to calculate a fitting formula, a geological signal, and an anisotropic signal.
In some exemplary embodiments, a signal processing process of the apparatus may be as follows.
In s11, an amplitude and a phase of an actually measured signal (a logging signal) of a double-tilted coil system of an azimuth electromagnetic wave logging while drilling instrument is sampled under a well by the sampling unit, as shown in dotted line waveforms in FIG. 6 and FIG. 7.
In s21, whether the signal is uniformly sampled is judged, if the sampled signal is not uniform, the act s31 or s41 is performed; and if the sampled signal is uniform, the act s51 is performed. The example signal in some periods is an uniform sampled signal, and the act s51 Date recite/Date received 2023-03-10 is performed; and the signal in some periods contains an empty sector, and the act s31 is performed.
When it is judged that the logging signal is not the uniformly sampled signal, two solutions may be selected: 1. after the act s31 is performed, that is, an empty sector is filled, the act s51 is performed; and 2. the act s41 is performed, that is, the fitted parameter is determined by adopting a preset non-uniform sampling signal fitting algorithm, and then the act s61 is performed. Here in the act 31, a solution of filling an empty sector by the inheritance approach is adopted, so the act s51 is performed after filling.
In s51, according to an orthogonal function theory, by taking a trigonometric function as a basis function, a fitting parameter of the uniformly sampled signal is obtained. Herein, a square term is a constant term, which is calculated in advance and stored in the storage unit.
The obtained fitted signal is shown as solid line waveforms in FIG. 5 and FIG.
6.
In s61, a geological signal and an anisotropic signal are calculated according to the fitting parameter (the fitted signal):
a phase geological signal:GP = arctan a0+a3+a1.
ao+aa-a1' an amplitude geological signal:GA = ¨20/og10 ao+a3+ai.
ao+aa-a1' a phase anisotropic signal:MP = arctan a04-a3+a1-a0-a3+a2' an amplitude anisotropic signal:MA = ¨20/og10 a0+a3+a1 ao-a3+a2 In some exemplary embodiments, the sampling unit is configured to perform signal sampling when an instrument rotates for one cycle, wherein a sampling quantity N in a single period is a constant, and a corresponding sampling angle in a single period xn is a fixed value;
N is an integer greater than 0, and .r71 is greater than or equal to 0 degree, and less than or equal to 360 degrees.

Date recue/Date received 2023-03-10 In some exemplary embodiments, the constant stored in the storage unit may be:
N N
= 1 COS2 X n Ns2 = 1 sin2 xn Nc2 n=1 n=1 N N
N2c2 1 cos2 2x77 N2s2 = 1 sin2 2x77 n=1 n=1 1 ' In some exemplary embodiments, when in s21 it is judged that the sampled signal is non-.. uniformly sampled, the act 31 is performed for filling; after filling, the sampled signal becomes an uniformly sampled signal, and the stored constant includes: N2. Ns2, N2c2, N22.
In some exemplary embodiments, a fitting coefficient calculation unit calculates a fitting parameter, also called a fitting formula coefficient, of a measuring signal in a structure of a double-tilted coil according to a signal sampling value; and a signal calculation unit calculates a geological signal, an anisotropic signal, etc. according to the fitting parameter.
In some exemplary embodiments, the amplitude geological signal, the phase geological signal, the amplitude anisotropic signal, and the phase anisotropic signal that are obtained by calculating are shown in FIGs. 7, 8, 9, and 10, respectively. It is easy to see that the apparatus has a simple structure, an easy implementation of the processing method, and a small calculation amount, and is suitable for a measuring environment under a well.
In some exemplary embodiments, when in s21 it is judged that the sampled signal is non-uniformly sampled, the act 41 is performed, that is, the fitting parameter is determined by adopting a preset non-uniform sampling signal fitting algorithm without performing filling.
In some exemplary embodiments, the empty sector may also be filled by adopting the interpolation approach in the act s31.
In some exemplary embodiments, the acts s21 to s61 are performed with reference to aspects corresponding to the acts s2 to s6 in the second embodiment, and are not repeated here.
In a word, it is proved by a theoretical calculation that the fitting formula obtained by the method for processing an azimuth electromagnetic wave logging while drilling signal is Date recite/Date received 2023-03-10 accurate, the obtained fitted signal is in a high consistency with the original signal, and the noise may also be suppressed; the actually measured signal proves that the apparatus for processing an azimuth electromagnetic wave logging while drilling signal is simple and easy in structure, reasonable, simple, and efficient in a process for processing an actual signal, and its signal .. processing effect is good, and accords with characteristics of the original signal.
It may be seen that the method described in this document is an explicit analytical method, and its time and space complexity is small; in addition, the solution process is based on the orthogonal function theory and accords with a least square principle, and can minimize errors.
An embodiment of the present disclosure also provides a method for processing an azimuth electromagnetic wave logging while drilling signal, a flow of which is shown in FIG.
12, including the following acts 1201 to 1203.
In the act 1201, a logging signal collected by an azimuth electromagnetic wave logging while drilling device is acquired.
In the act 1202, a fitting parameter of the logging signal is determined by taking a .. trigonometric function as a basis function according to an orthogonal function theory.
In the act 1203, stratum information corresponding to the logging signal is determined according to the fitting parameter, wherein the stratum information at least includes one of the following: a phase geological signal, an amplitude geological signal, a phase anisotropic signal, and an amplitude anisotropic signal.
Herein, the azimuth electromagnetic wave logging while drilling device is a device with a double-tilted coil system.
In some exemplary embodiments, the logging signal includes: sector measuring signals collected by rotating the double-tilted coil system of the azimuth electromagnetic wave logging while drilling device for one cycle according to a preset quantity of sampling times; and a waveform of a sector measuring signal is a second-order trigonometric function waveform with Date recite/Date received 2023-03-10 the following characteristics:
f (xn) = a0 +a1 cos xn +a7 sin xn +a3 cos 2xn +a4 sin 2x1 ( 1 ) f (xn)s the sector measuring signal, x n is a sector angle, a a a a 0, l , 2, wherein, 3, and a4 are fitting parameters.
In some exemplary embodiments, the fitting parameter of the logging signal is determined by taking the trigonometric function as the basis function according to the orthogonal function theory, which includes: whether the logging signal is sampled uniformly is judged; when the logging signal is sampled uniformly, according to the orthogonal function theory, by taking the trigonometric function as the basis function, the fitting parameter of the logging signal is determined by adopting a preset uniform sampling signal fitting algorithm; and when the logging signal is not sampled uniformly, performing filling for an empty sector of the logging signal, and for the filled signal, according to the orthogonal function theory, by taking the trigonometric function as the basis function, the fitting parameter of the logging signal is determined by adopting a preset uniform sampling signal fitting algorithm; or, according to the orthogonal function theory, by taking the trigonometric function as the basis function, the fitting parameter of the logging signal is determined by adopting a preset non-uniform sampling signal fitting algorithm.
In some exemplary embodiments, according to the orthogonal function theory, by taking the trigonometric function as the basis function, the fitting parameter of the logging signal is determined by adopting a preset non-uniform sampling signal fitting algorithm, which includes:
an accumulative summation is performed on the logging signal, the logging signal is multiplied with a preset trigonometric function and then an accumulative summation is performed, and two preset trigonometric functions are multiplied and then an accumulative summation is performed; a fitting matrix and a first fitting vector are determined according to results of all cumulative summations; wherein the preset trigonometric function is one or more of the following functions: cos xn, , sin xn, , cos 2.xn, , sin 2.xn, ;
correspondingly, a result of the Date recite/Date received 2023-03-10 cumulative summation after multiplying the logging signal with the preset trigonometric function is one or more; and the fitting parameter is determined according to the fitting matrix and the first fitting vector.
In some exemplary embodiments, according to an orthogonal function theory, by taking a trigonometric function as a basis function, a fitting parameter of the non-uniformly sampled signal is obtained, which includes: an accumulative summation is performed on the logging If(x) signal, a left side of formula (1) may be written as n=1 , and the right side thereof may be written as:
a0 + allcos x n + a21 sin xn + a,Icos 2x n + a 4 sin 2;
n=1 n=1 n=1 n=1 n=1 (2) An accumulative summation is performed on a product of multiplying the logging signal (xn)cos xn with a trigonometric function cos xn then the left side of formula (1) is nsi , and the right side thereof may be written as:
Eao cos xn + E cos2 xn a2 Leos xn sin xn + a,Ecos xn cos 2xn + a4Ecos xn sin 2xn n=1 n=1 n=1 n=1 n=1 (3) An accumulative summation is performed on a product of multiplying the logging signal (xn) sin xn with a trigonometric function sin xn , then the left side of formula (1) is nsi , and the right side thereof may be written as:
Ia0 sin xn + Icos xn sin xn + a2Isin2 Xn + a, sin xn cos 2x +a4sinxn sin 2x n=1 n=1 n=1 n=1 n=1 (4) An accumulative summation is performed on a product of multiplying the logging signal f (xn) cos 2xn with the trigonometric function cos 2xn , then the left side of formula (1) is nsi and the right side thereof may be written as:
Eao cos 2; + E cos; cos 2xn + a2 E sin xn cos 2; + a3 Ecos2 + a4 E cos 2xn sin 2;
n=1 n=1 n=1 n=1 n=1 (5) Date recite/Date received 2023-03-10 An accumulative summation is performed on a product of multiplying the logging signal f (xn) sin 2;
with a trigonometric function sin 2xn , then the left side of formula (1) is n=1 , and the right side thereof may be written as:
Eao sin 2xõ + a,Ecosx,õ sin 2xõ + a2 E sin x,õ sin 2xõ + a,E cos 2xõ sin 2xõ +
a,Esin22xõ
n=1 n=1 n=1 n=1 n=1 (6) Herein, a value of N represents a quantity of sampling values in each fitting, that is, a quantity of input values in a single fitting. For uniform sampling (without a null value), the value of N is equal to a quantity of sampling points in one period, and for non-uniform sampling (with the null value), the value of N is equal to a quantity of sampling points in one period minus a quantity of null values. In a process for fitting a non-uniformly sampled signal, the value of N is equal to the quantity of sampling points in one period minus the quantity of null values.
The parameter to be fitted a , a' , a2, C13 and a4 are calculated. Taking the following formulas:
Nc1 ICOS Xn Ns1 = sin Xn n=1 n=1 (7) N2c1 cos 2; N2s1 = sin 2;
n=1 n=1 (8) N fc f (xn) cos xn N f, f (xn) sin Xn n=1 n=1 (9) f (Xn) cos 2; Nf2s f (xn) sin 2xn Nf2c n=1 n=1 (10) Nc2 =ICOS2 x Ns2 sin2 xn Ncs = sin xn cos xn n=1 n=1 n=1 (11) N2c2 Icos2 2xn N2s2 = sin22xn N2c2s = cos 2x sin 2xn n=1 n=1 n=1 (12) N2cs cos 2x sin; N2sc =ICOS Xn sin 2x n=1 n=1 (13) Date recite/Date received 2023-03-10 N N
N255 I sin xn sin 2; N2õ = 1 cos xncos2xn n=1 n=1 (14) , Af = ¨1 f (xn) A, = ¨Icosxn As sin xn N n=1 N n=1 N n=1 (15) A2 = ¨1 cos 2xn 45 = ¨ I sin 2xn c N n¨i N n¨i (16) , The following formula may be obtained:
- a - - 1 - -1 -A2s Af 0 4 As A2c al Nc1 Nc2 N cs 'v2 cc N2sc Nfc az = '51 N cs N s2 N 2cs N 2ss N
fs a3 N2c N2cc N2c5 N2c2 N2c2s Nf 2c a4 ¨ N25 N25c N255 N2c23 N252 _ _Nf 2s _ ¨ ¨ (17) That is, a fitting parameter A [ a , a' , a2, a3, a41 is determined according to a fitting matrix T and a first fitting vector M; wherein the fitting matrix T is -1 4 As 4c 4s Nc1 Nc2 Ncs N2cc N25c N sl N cs N s2 N25 N255 ;
N 2c N2cc N 2cs N2c2 N2c25 _N2s N2 sc N2ss N2c25 N2s2 _ The first fitting vector M is -Af Nfc N
fs =
Nf 2c _Nf 2s _ Thereby, the fitting parameterA =7-1 M.
In some exemplary embodiments, according to the orthogonal function theory, by taking the trigonometric function as the basis function, the fitting parameter of the logging signal is determined by adopting the preset uniform sampling signal fitting algorithm, which includes:

Date recite/Date received 2023-03-10 an average operation is performed on the logging signal to obtain an average value, the logging signal is multiplied with a preset trigonometric function and then an accumulative summation is performed, an accumulative summation is performed on a square of a preset trigonometric function; a second fitting vector is determined according to the average value and results of all accumulative summations; wherein the preset trigonometric function is one or more of the following functions: cos xn, sin xn, cos 2.xn, and sin 2.xn; correspondingly, a result of the cumulative summation after multiplying the logging signal with the preset trigonometric function is one or more; and the fitting parameter is determined according to the second fitting vector.
In some exemplary embodiments, according to the orthogonal function theory, by taking the trigonometric function as the basis function, the fitting parameter of the logging signal is determined by adopting the preset uniform sampling signal fitting algorithm, which includes:

Af =f(x1) n=1 the logging signal is averaged to obtain: N=
an accumulative summation is performed on a product of multiplying the logging signal N fc = f(x1) cos xn with a trigonometric function cos xn to obtain: n=1 =
an accumulative summation is performed on a product of multiplying the logging signal N fs f (x n) sin x77with a trigonometric function sinxn to obtain: n=1 an accumulative summation is performed on a product of multiplying the logging signal = N f n) COS 2xn f 2 c with a trigonometric function cos 2x to obtain: n=1 =
an accumulative summation is performed on a product of multiplying the logging signal N f 2 s = f (X n) sin 2;
with a trigonometric function to obtain: n=1 =ICOS2 x Ns2 sin2 xn N22 Icos2 2x77 Nc2 square terms are calculated: n=1 n=1 n=1 Date recite/Date received 2023-03-10 N2s2 sin2 2xn and n=1 Herein, a value of N represents a quantity of sampling values in each fitting, that is, a quantity of input values in a single fitting. For uniform sampling (without a null value), the value of N is equal to a quantity of sampling points in one period, and for non-uniform sampling (with the null value), the value of N is equal to a quantity of sampling points in one period minus a quantity of null values. In a process for fitting an uniformly sampled signal, the value of N is equal to the quantity of sampling points in one period.
A second fitting vector Q [A f , Nf c, Nfs, Nf2c, Nf2s, Ara, Ns2, N2c2, N2s2]
is determined.
According to the second fitting vector Q, parameters to be fitted are obtained, including:
Nic a =N fs a = Nf 2c a4 = N12 a = __ a0 = Af 1 Nc2 2 Ns2 3 N2c2 , and N2 s2 In some exemplary embodiments, a structure of the double-tilted coil system includes:
transmitting and receiving coils, which are not along an axial direction of an instrument, but respectively form a certain included angle with the axial direction; wherein the axial direction of the instrument includes three axial directions of a three-dimensional rectangular coordinate system.
In some exemplary embodiments, filling is performed for an empty sector of the logging signal, which includes: for each empty sector, performing filling according to one of the following modes: determining filling data according to logging signals of sectors at two sides of the empty sector, and filling the empty sector with the determined filling data; and filling the empty sector according to a corresponding logging signal of the empty sector in a previous measuring period.
In some exemplary embodiments, the waveform of the sector measuring signal also has the following characteristics:
f (xn) = bo + k cos(x, + coi)+ b2 cos(2x1+co2) Date recite/Date received 2023-03-10 b b b2 co , , l , and C 2 b a meet the following relationships: wherein, 0 , 1 , bi cos coi = a, bi sin goi = ¨a2 b2 cos c02 = a, , and b2 sin (02 = ¨a, , , An embodiment of the present disclosure also provides an apparatus 130 for processing an azimuth electromagnetic wave logging while drilling signal, the structure of which is shown in FIG. 13, including: a signal acquisition module 1301, a fitting module 1302, and an information determination module 1303.
The signal acquisition module 1301 is configured to acquire a logging signal collected by an azimuth electromagnetic wave logging while drilling device.
The fitting module 1302 is configured to, according to an orthogonal function theory, by taking a trigonometric function as a basis function, determine a fitting parameter of the logging signal.
The information determination module 1303 is configured to determine stratum information corresponding to the logging signal according to the fitting parameter, wherein the stratum information at least includes one of the following: a phase geological signal, an amplitude geological signal, a phase anisotropic signal, and an amplitude anisotropic signal.
Herein, the azimuth electromagnetic wave logging while drilling device is a device with a double-tilted coil system.
An embodiment of the present disclosure further provides an electronic apparatus, including a memory and a processor, wherein the memory stores a computer program for processing an azimuth electromagnetic wave logging while drilling signal, and the processor is configured to read and run the computer program for processing the azimuth electromagnetic wave logging while drilling signal to perform any of the above methods for processing the azimuth electromagnetic wave logging while drilling signal.
An embodiment of the present disclosure further provides a storage medium, in which a computer program is stored, wherein the computer program is configured to perform any of the Date recite/Date received 2023-03-10 above methods for processing the azimuth electromagnetic wave logging while drilling signal when being run.
Those of ordinary skill in the art can appreciate that all or some of the acts in the above disclosed methods, systems, functional modules/units in apparatuses may be implemented as software, firmware, hardware, and appropriate combinations thereof. In hardware embodiments, a division between functional modules/units mentioned in the above description does not necessarily correspond to a division of physical components; for example, a physical component may have multiple functions, or a function or an act may be performed cooperatively by several physical components. Some or all of the components may be implemented as software executed by a processor, such as a digital signal processor or a microprocessor, or as hardware, or as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer storage medium (or a non-transient medium) and a communication medium (or a transient medium). As is well known to those of ordinary skill in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technique for storing information, such as computer-readable instructions, data structures, program modules, or other data.
Computer storage media include, but are not limited to, RAM, ROM, EEPROM, a flash memory, or another memory technology, CD-ROM, a digital versatile disk (DVD) or another optical disk storage, a magnetic .. cartridge, a magnetic tape, a magnetic disk storage or another magnetic storage apparatus, or any other medium that may be configured to store desired information and may be accessed by a computer. In addition, it is well known to those of ordinary skill in the art that the communication medium typically contains computer readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or another transmission mechanism, and may include any information delivery medium.

Date recite/Date received 2023-03-10

Claims

Claims:

1. A method for processing an azimuth electromagnetic wave logging while drilling signal, comprising, acquiring a logging signal collected by an azimuth electromagnetic wave logging while drilling device;
determining a fitting parameter of the logging signal by taking a trigonometric function as a basis function according to an orthogonal function theory; and determining stratum information corresponding to the logging signal according to the fitting parameter, wherein the stratum information at least comprises one of the following: a phase geological signal, an amplitude geological signal, a phase anisotropic signal, and an amplitude anisotropic signal;
wherein, the azimuth electromagnetic wave logging while drilling device is a device with a double-tilted coil system.

2. The method of claim 1, wherein, the logging signal comprises: sector measuring signals collected by rotating the double-tilted coil system of the azimuth electromagnetic wave logging while drilling device for one cycle according to a preset quantity of sampling times;
a waveform of a sector measuring signal is a second-order trigonometric function waveform with the following characteristics:
f (xõ)= ao + al cos xn + a2 sin +a3 cos 2x, +a4 sin 2.x, . f (x ) . a a a wherein, n is the sector measuring si x gnal, n i a s a sector angle, 0, 1, 2, 3 , and a4 are fitting parameters.

3. The method of claim 2, wherein, determining the fitting parameter of the logging signal by taking the trigonometric function as the basis function according to the orthogonal function theory comprises:
judging whether the logging signal is sampled uniformly;
when the logging signal is sampled uniformly, according to the orthogonal function theory, by taking the trigonometric function as the basis function, determining the fitting parameter of the logging signal by adopting a preset uniform sampling signal fitting algorithm; and when the logging signal is not sampled uniformly, performing filling for an empty sector of the logging signal, and for the filled signal, according to the orthogonal function theory, by taking the trigonometric function as the basis function, determining the fitting parameter of the logging signal by adopting a preset uniform sampling signal fitting algorithm;
or, according to the orthogonal function theory, by taking the trigonometric function as the basis function, determining the fitting parameter of the logging signal by adopting a preset non-uniform sampling signal fitting algorithm.

4. The method of claim 3, wherein, according to the orthogonal function theory, by taking the trigonometric function as the basis function, determining the fitting parameter of the logging signal by adopting the preset non-uniform sampling signal fitting algorithm comprises:
performing an accumulative summation on the logging signal, multiplying the logging signal with a preset trigonometric function and then performing an accumulative summation, and multiplying two preset trigonometric functions and then performing an accumulative summation; determining a fitting matrix and a first fitting vector according to results of all cumulative summations; wherein the preset trigonometric function is one or more of the following functions: cos xn, , sin xn, , cos 2xn, ,and sin 2xn, ;
correspondingly, a result of the cumulative summation after multiplying the logging signal with the preset trigonometric function is one or more; and determining the fitting parameter according to the fitting matrix and the first fitting vector.

5. The method of claim 3, wherein, according to the orthogonal function theory, by taking the trigonometric function as the basis function, determining the fitting parameter of the logging signal by adopting the preset uniform sampling signal fitting algorithm comprises:
performing an average operation on the logging signal to obtain an average value, multiplying the logging signal with a preset trigonometric function and then performing an accumulative summation, performing an accumulative summation on a square of a preset trigonometric function; determining a second fitting vector according to the average value and results of all accumulative summations; wherein the preset trigonometric function is one or more of the following functions: cos xn, sin xn, cos 2x, sin 2xn;
correspondingly, a result of the cumulative summation after multiplying the logging signal with the preset trigonometric function is one or more; and determining the fitting parameter according to the second fitting vector.

6. The method of claim 1, wherein, a structure of the double-tilted coil system comprises:
transmitting and receiving coils, which respectively form a certain included angle with an axial direction of an instrument; wherein the axial direction of the instrument comprises three axial directions of a three-dimensional rectangular coordinate system.

7. The method of claim 3, wherein, performing filling for the empty sector of the logging signal comprises:
for each empty sector, performing filling according to one of the following modes:
determining filling data according to logging signals of sectors at two sides of the empty sector, and filling the empty sector with the determined filling data; and filling the empty sector according to a corresponding logging signal of the empty sector in a previous measuring period.

8. The method of claim 2, wherein, the waveform of the sector measuring signal further has the following characteristics:
f (xn) = bo + b cos(x, + ) + b2 cos(2x, c02 ) wherein, 0 , b b b 2 v1 , and CD2 meet the following relationshi b ps:
bsino = a, k cos col = ¨a2 b2 cos = a, , and b2 sin c02 = ¨a,

9. An electronic apparatus, comprising a memory and a processor, wherein the memory stores a computer program for processing an azimuth electromagnetic wave logging while drilling signal, and the processor is configured to read and run the computer program for processing the azimuth electromagnetic wave logging while drilling signal to perform the method of any one of claims 1 to 8.

10. A storage medium, having a computer program stored therein, wherein the computer program is configured to perform the method of any one of claims 1 to 8 when being run.