Note: Descriptions are shown in the official language in which they were submitted.
CA 03194763 2023-03-10
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
1
Date recite/Date received 2023-03-10
CA 03194763 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
CA 03194763 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
CA 03194763 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
CA 03194763 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
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
CA 03194763 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
CA 03194763 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
CA 03194763 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
CA 03194763 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
CA 03194763 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)
1 N 1 N 1 N
A = ¨If (x ) Ac = Icosxn As = ¨I sin xn
f N n 1 n (15)
Date recite/Date received 2023-03-10
CA 03194763 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
11
Date recite/Date received 2023-03-10
CA 03194763 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.
1 N
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
12
Date recite/Date received 2023-03-10
CA 03194763 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.
13
Date recite/Date received 2023-03-10
CA 03194763 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 =
14
Date recue/Date received 2023-03-10
CA 03194763 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
15
Date recite/Date received 2023-03-10
CA 03194763 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.
16
Date recue/Date received 2023-03-10
CA 03194763 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
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
17
Date recite/Date received 2023-03-10
CA 03194763 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
18
Date recite/Date received 2023-03-10
CA 03194763 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
19
Date recite/Date received 2023-03-10
CA 03194763 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
CA 03194763 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)
21
Date recite/Date received 2023-03-10
CA 03194763 2023-03-10
N N
N255 I sin xn sin 2; N2õ = 1 cos xncos2xn
n=1 n=1 (14)
,
1 N 1 N 1 N
Af = ¨1 f (xn) A, = ¨Icosxn As sin xn
N n=1 N n=1 N n=1 (15)
1 N 1 N
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:
22
Date recite/Date received 2023-03-10
CA 03194763 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:
1 N
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
23
Date recite/Date received 2023-03-10
CA 03194763 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)
24
Date recite/Date received 2023-03-10
CA 03194763 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
CA 03194763 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.
26
Date recite/Date received 2023-03-10
