Method, device and equipment for acquiring oil-water contrast ratio of full-spectrum logging data

Abstract

The invention discloses a method, a device and equipment for acquiring the oil-water contrast ratio of full-spectrum logging data. The method comprises the following steps: determining an original energy spectrum of the full-spectrum logging data; based on the original energy spectrum, a first degradation energy spectrum of the full-spectrum logging data is determined, and the first degradation energy spectrum is used for reducing the influence of the Compton scattering effect on the original energy spectrum; performing energy spectrum degradation processing on the original energy spectrum based on the first degradation energy spectrum to obtain a target energy spectrum of the full-spectrum logging data; and based on the target energy spectrum, obtaining the oil-water contrast ratio of the full-spectrum logging data. According to the invention, the technical problem that the Compton scattering effect has great influence on the oil-water contrast precision of the full-spectrum logging data is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of mineral resource exploration, and in particular relates to a method, a device and equipment for obtaining oil-water contrast of full-spectrum logging data. Background Art

[0002] The use of pulsed neutron sources to measure formation skeletons and fluid parameters has been widely used in the field of mineral resource exploration such as oil, natural gas, coal, and metals. Pulsed neutron sources are used to measure and analyze the content of various elements in rocks, coal, or other mineral deposits, as well as the oil and gas content in oil and gas wells. The pulsed neutron flow reacts with the substances in the formation, and the gamma rays such as inelastic gamma, captured gamma, and activated gamma generated in the reaction are recorded to obtain the energy spectrum, and finally the oil-water contrast of the full spectrum logging data is obtained. In this process, the returned gamma rays, due to effects such as Compton scattering, excite the atoms in the crystal to release photons, and after several reactions, they reach the photocathode of the photomultiplier tube and are finally converted into an electrical pulse signal corresponding to the energy. The scintillation counter composed of crystals and photomultiplier tubes has energy resolution and statistical fluctuations in the measurement of gamma rays, resulting in large errors in the oil-water contrast of the obtained full spectrum logging data, which affects the subsequent completion and development of oil fields. Therefore, the Compton scattering effect has a great influence on the accuracy of the oil-water contrast of the full spectrum logging data, which is a technical problem that needs to be solved urgently. Summary of the invention

[0003] The embodiments of the present invention provide a method, device and equipment for obtaining oil-water contrast of full-spectrum logging data, which solve the technical problem that the Compton scattering effect has a significant impact on the oil-water contrast accuracy of full-spectrum logging data.

[0004] In a first aspect, an embodiment of the present invention provides a method for acquiring oil-water contrast of full-spectrum logging data, comprising: determining an original energy spectrum of the full-spectrum logging data; based on the original energy spectrum, determining a first degraded energy spectrum of the full-spectrum logging data, the first degraded energy spectrum being used to reduce the influence of Compton scattering effect on the original energy spectrum; performing energy spectrum degradation processing on the original energy spectrum based on the first degraded energy spectrum to obtain a target energy spectrum of the full-spectrum logging data; based on the target energy spectrum, acquiring the oil-water contrast of the full-spectrum logging data.

[0005] In combination with the first aspect of the present invention, in some embodiments, determining the first degraded energy spectrum of the full-spectrum logging data based on the original energy spectrum includes: determining the second slope based on the input first slope and amplification factor; determining the first energy window and the second energy window of the original energy spectrum; determining the first change acceleration of the counts in the first energy window, and determining the second change acceleration of the counts in the second energy window; determining the second degraded energy spectrum based on the second slope and the first change acceleration; determining the third degraded energy spectrum based on the first slope and the second change acceleration; comparing the photon count of each channel address of the second degraded energy spectrum with the photon count of the corresponding channel address in the third degraded energy spectrum, and obtaining the first degraded energy spectrum based on the larger photon count.

[0006] In combination with the first aspect of the present invention, in some embodiments, the energy spectrum degradation processing is performed on the original energy spectrum based on the first degradation energy spectrum to obtain the target energy spectrum of the full-spectrum logging data, including: subtracting the photon count of each channel address in the original energy spectrum from the photon count of the corresponding channel address in the first degradation energy spectrum to obtain the target energy spectrum.

[0007] In combination with the first aspect of the present invention, in some embodiments, determining the first energy window and the second energy window of the original energy spectrum includes: obtaining a target energy window and a hydrogen peak of the original energy spectrum; and dividing the target energy window into the first energy window and the second energy window based on the hydrogen peak.

[0008] In combination with the first aspect of the present invention, in some embodiments, determining the first change acceleration of the count in the first energy window includes: obtaining a first coefficient, a first photon count sum in the first energy window, and a first channel address number in the first energy window; based on the first coefficient, the first photon count sum, and the first channel address number, determining the first change acceleration of the count in the first energy window; determining the second change acceleration of the count in the second energy window includes: obtaining a second coefficient, a second photon count sum in the second energy window, and a second channel address number in the second energy window; based on the second coefficient, the second photon count sum, and the second channel address number, determining the second change acceleration of the count in the second energy window.

[0009] In combination with the first aspect of the present invention, in some embodiments, determining the first degradation energy spectrum of the full-spectrum logging data based on the original energy spectrum includes: performing a logarithmic transformation on the original energy spectrum to obtain a first energy spectrum; determining an approximate straight line of the first energy spectrum; obtaining a straight line slope and a straight line intercept of the approximate straight line; and determining the first degradation energy spectrum based on the straight line slope, the straight line intercept and an input compensation value.

[0010] In combination with the first aspect of the present invention, in some embodiments, the energy spectrum degradation processing is performed on the original energy spectrum based on the first degradation energy spectrum to obtain the target energy spectrum of the full-spectrum logging data, including: exponentially transforming the first degradation energy spectrum to obtain a fourth degradation energy spectrum; subtracting the photon count of each channel address in the original energy spectrum from the photon count of the corresponding channel address in the fourth degradation energy spectrum to obtain a second energy spectrum; comparing the photon count of each channel address in the original energy spectrum with the photon count of the corresponding channel address in the second energy spectrum, and obtaining the target energy spectrum based on the smaller photon count.

[0011] In combination with the first aspect of the present invention, in some embodiments, determining the approximate straight line of the first energy spectrum includes: obtaining a first channel address and a second channel address; obtaining a first photon count corresponding to the first channel address on the first energy spectrum, and a second photon count corresponding to the second channel address on the first energy spectrum; and obtaining the approximate straight line based on the first channel address, the first photon count, the second channel address and the second photon count.

[0012] In the second aspect, an embodiment of the present invention provides an oil-water contrast acquisition device for full-spectrum logging data, comprising: an original determination unit, used to determine the original energy spectrum of the full-spectrum logging data; a degradation determination unit, used to determine a first degradation energy spectrum of the full-spectrum logging data based on the original energy spectrum, the first degradation energy spectrum being used to reduce the influence of Compton scattering effect on the original energy spectrum; a target determination unit, used to perform energy spectrum degradation processing on the original energy spectrum based on the first degradation energy spectrum to obtain a target energy spectrum of the full-spectrum logging data; a contrast acquisition unit, used to acquire the oil-water contrast of the full-spectrum logging data based on the target energy spectrum.

[0013] In a third aspect, an embodiment of the present invention provides an electronic device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements any one of the methods described in the first aspect when executing the computer program.

[0014] One or more technical solutions provided by the embodiments of the present invention achieve at least the following technical effects or advantages:

[0015] The embodiment of the present invention determines the original energy spectrum of the full spectrum logging data; determines the first degraded energy spectrum of the full spectrum logging data based on the original energy spectrum, and the first degraded energy spectrum is used to reduce the influence of the Compton scattering effect on the original energy spectrum; performs energy spectrum degrade processing on the original energy spectrum based on the first degraded energy spectrum to obtain the target energy spectrum of the full spectrum logging data; and obtains the oil-water contrast of the full spectrum logging data based on the target energy spectrum. The energy spectrum degrade processing is performed on the original energy spectrum by the first degraded energy spectrum, so that the accuracy of the photon count of each channel in the energy spectrum is improved, so that the influence of the Compton scattering effect on the oil-water contrast accuracy of the full spectrum logging data is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 Flow chart of a method for acquiring oil-water contrast ratio of full spectrum logging data in an embodiment of the present invention;

[0018] Figure 2 Schematic diagram of the distribution of the dominant areas of the three photon effects in an embodiment of the present invention;

[0019] Figure 3 A schematic diagram of the reaction of Compton scattering in an embodiment of the present invention;

[0020] Figure 4 is an ideal spectrum of energy and photon counts in an embodiment of the present invention;

[0021] Figure 5 is a schematic diagram of Compton scattering in an actual measurement process in an embodiment of the present invention;

[0022] Figure 6 The actual measurement spectrum of energy and photon counts in the embodiment of the present invention;

[0023] Figure 7 This is a schematic diagram of a crystal receiving gamma rays under a working environment in an embodiment of the present invention;

[0024] Figure 8 This is a logarithmic image after degradation using Scheme 1 for the test data of a 37.5 mm crystal oil tank in an embodiment of the present invention;

[0025] Fig. 9 for Figure 8 The corresponding linear image;

[0026] Fig.10This is a logarithmic image of the test data of the 37.5 mm crystal oil tank after degradation using Scheme 2 in the embodiment of the present invention;

[0027] Fig.11 for Fig.10 The corresponding linear image;

[0028] Fig.12 This is a functional module diagram of the oil-water contrast acquisition device for full spectrum logging data in an embodiment of the present invention;

[0029] Fig.13 Schematic diagram of the structure of an electronic device in an embodiment of the present invention. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] In the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0032] The embodiment of the present invention provides a method for obtaining oil-water contrast of full spectrum logging data, referring to Figure 1 As shown, the method includes the following steps S101 to S104:

[0033] S101: Determine the original energy spectrum of the full spectrum logging data.

[0034] It is understandable that the first energy spectrum of the full spectrum logging data can be obtained by reacting the pulsed neutron flux with the full spectrum logging data.

[0035] S102: Determine a first degraded energy spectrum of the full-spectrum logging data based on the original energy spectrum, where the first degraded energy spectrum is used to reduce the influence of the Compton scattering effect on the original energy spectrum.

[0036] It can be understood that determining the first falloff energy spectrum of the full spectrum logging data based on the original energy spectrum may include the following steps S102A to S102F:

[0037] S102A: Determine a second slope based on the input first slope and amplification factor.

[0038] It is understandable that the product of the first slope and the magnification factor can be directly used as the second slope, wherein the magnification factor and the first slope are empirical values. For example, the magnification factor can be 1.5 and the first slope can be 2.2.

[0039] S102B: Determine the first energy window and the second energy window of the original energy spectrum.

[0040] It can be understood that determining the first energy window and the second energy window of the original energy spectrum may include: acquiring the target energy window and the hydrogen peak of the original energy spectrum; and dividing the target energy window into the first energy window and the second energy window based on the hydrogen peak.

[0041] S102C: Determine a first change acceleration of the counts in the first energy window, and determine a second change acceleration of the counts in the second energy window.

[0042] It can be understood that determining the first change acceleration of the count in the first energy window may include: obtaining the first coefficient, the first photon count sum of the first energy window, and the first track number of the first energy window; based on the first coefficient, the first photon count sum, and the first track number, determining the first change acceleration of the count in the first energy window. It should be noted that the first track number of the first energy window refers to the number of tracks in the first energy window. For example, the first energy window includes track 7, track 8, and track 9, then the first track number of the first energy window is 3. The first photon count sum of the first energy window refers to the sum of all photons in all tracks of the first energy window. For example, the first energy window includes track 7, track 8, and track 9, track 7 contains a photons, track 8 contains b photons, and track 9 contains c photons, then the first photon count sum of the first energy window is a+b+c. The first coefficient is an input empirical coefficient.

[0043] It can be understood that determining the second change acceleration of the count in the second energy window may include: obtaining the second coefficient, the second photon count sum of the second energy window, and the second track number of the second energy window; based on the second coefficient, the second photon count sum, and the second track number, determining the second change acceleration of the count in the second energy window. It should be noted that the second track number of the second energy window refers to the number of tracks in the second energy window. For example, the second energy window includes track 4, track 5, and track 6, then the second track number of the second energy window is 3. The second photon count sum of the second energy window refers to the sum of all photons in all tracks of the second energy window. For example, the second energy window includes track 4, track 5, and track 6, track 4 contains a photons, track 5 contains b photons, and track 6 contains c photons, then the second photon count sum of the second energy window is a+b+c. The second coefficient is an input empirical coefficient.

[0044] In some implementations, the first change acceleration may be calculated using the following formula:

[0045]

[0046] Among them, Sum1 is the first change acceleration, a is the first coefficient, b is the first photon count sum, and c is the first channel number. Sum2 is the second change acceleration, d is the second coefficient, e is the second photon count sum, and f is the second channel number. It should be noted that Sum1 and Sum2 also represent the second-order derivative of the photon count with respect to the channel address. The physical meaning of Sum1 and Sum2 is the acceleration of the photon count in each energy segment relative to the corresponding channel address of the energy segment. The first coefficient and the second coefficient are empirical coefficients used to adjust the direction of the spectral line. Their physical meaning is the average photon density in the corresponding energy window.

[0047] S102D: Determine a second degradation energy spectrum based on the second slope and the first change acceleration.

[0048] S102E: Determine a third degradation energy spectrum based on the first slope and the second change acceleration.

[0049] Specifically, the second decay energy spectrum can be expressed by the following formula:

[0050]

[0051] Among them, data2(i) represents the second decay energy spectrum, Sum1 is the first change acceleration, and k2 is the second slope. data3(i) represents the third decay energy spectrum, Sum2 is the second change acceleration, and k1 is the first slope. It should be noted that there are 256 channel addresses of the spectrum line, and i represents the i-th channel address.

[0052] S102F: Compare the photon count of each channel in the second de-rating energy spectrum with the photon count of the corresponding channel in the third de-rating energy spectrum, and obtain the first de-rating energy spectrum based on the larger photon count.

[0053] Specifically, the first degradation energy spectrum can be expressed by the following formula:

[0054]

[0055] Wherein, data1(i) represents the first degraded energy spectrum, data2(i) represents the second degraded energy spectrum, and data3(i) represents the third degraded energy spectrum.

[0056] It can be understood that, based on the original energy spectrum, the method for determining the first falloff energy spectrum of the full spectrum logging data can also be steps S102G to S102J:

[0057] S102G: Perform logarithmic transformation on the original energy spectrum to obtain a first energy spectrum.

[0058] It can be understood that performing logarithmic transformation on the original energy spectrum may be: taking the logarithm of the photon count in the original energy spectrum as base 10 to obtain the first energy spectrum.

[0059] S102H: Determine an approximate straight line of the first energy spectrum.

[0060] In some embodiments, determining an approximate straight line of the first energy spectrum includes: obtaining a first channel address and a second channel address; obtaining a first photon count corresponding to the first channel address on the first energy spectrum, and a second photon count corresponding to the second channel address on the first energy spectrum; obtaining an approximate straight line based on the first channel address, the first photon count, the second channel address, and the second photon count. It is understandable that a first point on the first energy spectrum can be determined based on the first channel address and the first photon count, and a second point on the first energy spectrum can be determined based on the second channel address and the second photon count, and the first point and the second point are connected to obtain an approximate straight line. It should be noted that the first channel address can be 60, and the second channel address can be 68.

[0061] S102I: Get the slope and intercept of an approximate straight line.

[0062] S102J: Determine a first degradation energy spectrum based on the straight line slope, the straight line intercept and the input compensation value.

[0063] Specifically, the first degradation energy spectrum can be expressed by the following formula:

[0064] data1(i)=i×k+b1+b2;

[0065] Wherein, data1(i) represents the first decay energy spectrum, k represents the slope of the straight line, b1 represents the intercept of the straight line, and b2 represents the compensation value, which may be -0.41.

[0066] S103: performing energy spectrum degradation processing on the original energy spectrum based on the first degradation energy spectrum to obtain a target energy spectrum of the full spectrum logging data.

[0067] It should be noted that step S102 can be completed by steps S102G to S102J or steps S102A to S102F to obtain a first decayed energy spectrum, but the first decayed energy spectrum obtained by steps S102G to S102J and steps S102A to S102F is not the same. Therefore, for the two different situations, the energy spectrum decay processing in step S103 is also different, which are described separately below.

[0068] If step S102 specifically includes steps S102A to S102F, correspondingly, step S103 may include step S1031: subtracting the photon count of each channel address in the original energy spectrum from the photon count of the corresponding channel address in the first degradation energy spectrum to obtain the target energy spectrum.

[0069] Among them, the target energy spectrum can be expressed by the following formula:

[0070] A1(i)=A0(i)-data1(i);

[0071] Among them, A0(i) represents the original energy spectrum, A1(i) represents the target energy spectrum, and data1(i) represents the first degradation energy spectrum.

[0072] It can be understood that, with respect to steps S102G to S102J, step S103 may include steps S1032 to S1034:

[0073] Step S1032: performing exponential transformation on the first decay energy spectrum to obtain a fourth decay energy spectrum.

[0074] In an understandable manner, the method of performing exponential transformation on the first degraded energy spectrum to obtain the fourth degraded energy spectrum may be: taking the exponent of 10 for the photon count of the first degraded energy spectrum to obtain the fourth degraded energy spectrum.

[0075] Step S1033: Subtract the photon count of each channel in the original energy spectrum from the photon count of the corresponding channel in the fourth degraded energy spectrum to obtain a second energy spectrum.

[0076] Step S1034: Compare the photon count of each channel in the original energy spectrum with the photon count of the corresponding channel in the second energy spectrum, and obtain the target energy spectrum based on the smaller photon count.

[0077] It can be understood that the method of comparing the photon count of each channel address in the original energy spectrum with the photon count of the corresponding channel address in the second energy spectrum and obtaining the target energy spectrum based on the smaller photon count can be: comparing the photon count of each channel address in the original energy spectrum with the photon count of the corresponding channel address in the second energy spectrum, and taking the smaller photon count as the photon count of the corresponding channel address in the target energy spectrum. The smaller photon count must be greater than 0.

[0078] Specifically, the target energy spectrum can be expressed by the following formula:

[0079]

[0080] Among them, A0(i) represents the original energy spectrum, A1(i) represents the target energy spectrum, data1(i) represents the first degraded energy spectrum, and B(i) represents the first energy spectrum.

[0081] It should be noted that the energy spectrum degradation process is completed through the above steps S102G to S102J and steps S1032 to S1034. The counts of the degradation energy spectrum in the low energy segment will be reduced by a large part. As the energy increases, the data will decrease and gradually approach 0 in the high energy segment. The overall change trend is similar to an exponential function. This is in line with the law of actual data. In addition, the default values ​​of the above parameters will also be different depending on the type of spectrum.

[0082] S104: Obtaining oil-water contrast of full spectrum logging data based on the target energy spectrum.

[0083] It should be noted that the image of the photon count of the original energy spectrum decays in an exponential function, which is caused by various factors such as instrument background, count accumulation, Compton scattering effect and other effects. Therefore, a decaying energy spectrum simulation that conforms to the exponential law can be made to decay the original energy spectrum, thereby reducing the impact. The impact of the Compton effect is similar to an exponential function, and the image after taking the logarithm is similar to a linear function. Based on this, two methods are provided. Steps S102A to S102F divide the energy window into segments based on the hydrogen peak, calculate them separately and then synthesize them to obtain the decaying energy spectrum; steps S102G to S102J analyze the logarithmic image of the data, specify the starting and ending addresses and compensation values, and draw the decaying energy spectrum. The two schemes have different effects on various data such as carbon-oxygen ratio, silicon-calcium ratio and other results, and the user can make their own choices based on the usage scenario.

[0084] It should be noted that Compton scattering causes fluctuations in the energy spectrum. The following explains the Compton scattering effect and the principle of its influence on the energy spectrum:

[0085] refer to Figure 2 From the distribution of the dominant areas of the three photon effects, it can be seen that the Compton effect is an important reason for the decrease in spectral measurement accuracy. Gamma photons collide with the outer electrons of atoms, causing them to break free from the atoms' binding energy and become recoil electrons. In this process, the incident photons lose energy and their frequency changes, forming scattered photons. Considering the incident photons, electrons and scattered photons as a system, this process can be described as follows:

[0086] L(E γ , E e )→L′(E γ′ , E e′ );

[0087] E e and E e′ They represent the energy of the electron before and after the collision, E γ and E γ′They represent the energy of the photon before and after the collision. Compton scattering mainly occurs in the outer electrons, and the binding energy required to make them escape from the atom is much smaller than the energy of other particles involved in the discussion, so it is ignored. It should be noted that when discussing the Compton effect, it is assumed that the electron is stationary. Figure 3 As shown, Figure 3 Schematic diagram of the Compton scattering reaction.

[0088] First, for the outer electrons, it is easy to know from the atomic structure that some photons may collide with the inner electrons during the reaction. However, since the inner bound electrons are tightly bound to the atoms, this is essentially equivalent to colliding with the atoms themselves. In the following discussion, the atomic rest mass should be used for calculations, which will result in a change in wavelength close to 0, and there is no need to discuss it. This is why Compton scattering is mainly for the outer electrons that can be approximately regarded as free.

[0089] Secondly, for stationary electrons, the Compton effect assumes that the electrons are stationary. In fact, electrons are certainly not stationary. So when calculating E e The m0 used is actually Since this article is a qualitative discussion, this will not affect the results. When photons are Compton scattered inside the crystal, according to the energy and momentum conservation of the system, combined with the cosine theorem:

[0090]

[0091] Among them, E and p represent the energy and momentum of the corresponding particle respectively, Ee=m0c 2 is the rest energy of a free electron, and represents the momentum of the incident photon and the scattered photon, λ and λ′ represent their wavelengths, and h is Planck's constant. Photons are particles moving at the speed of light, and the relationship of relativity needs to be used:

[0092] E γ =hv

[0093] E γ' =hv'

[0094]

[0095] E e' =m e' c 2

[0096]

[0097] In the above formula, v represents the velocity of the recoil electron, and v and v′ represent the frequencies of the incident photon and the scattered photon, respectively. Substituting the above cosine theorem, we can get the Compton scattering formula:

[0098]

[0099] After transformation, the angle θ and the energy E of the incident gamma can be used γ To represent the energy of recoil electrons and scattered photons. e′ Represents the energy of the recoil electron, E γ′ Represents the energy of the scattered photon. Naturally, we define mapping f and mapping g to represent the angle θ and incident gamma energy E, respectively. γ Relationship:

[0100]

[0101]

[0102] For any given element, the characteristic gamma E γ The energy of is uniquely determined. At this time, the above formula can be deduced separately, E e′ and E γ′ It will be uniquely determined by θ. That is, for any element X, the mapping relationship between the energy of the recoil electron or scattered photon and the scattering angle θ can be obtained:

[0103] E e' =f X (θ)

[0104] E γ' =g X (θ)

[0105] Due to the physical structure of the instrument, the domain of θ cannot be the complete interval [0,2π], but it must be included in it, and it is a continuous or piecewise continuous interval. Thus, E e′ and E γ′ The value range U(E e′ ) and U(E γ′ ) are also continuous or piecewise continuous intervals:

[0106] U(E e' )∶=(E e11 ,E e12 )∪(E e13 ,E e14 )∪···,E e' ∈U(E e' )

[0107] U(E γ' )∶=(E γ11 ,E γ12 )∪(E γ13 ,E γ14 )∪···,E γ'∈U(E γ' )

[0108] Now let's focus on the recoil electrons generated by the reaction. The recoil electrons excite and de-excite the atoms of the material, and emit photons γ1 in the process. This process will not be elaborated in detail here, but it is only necessary to clarify the energy E of the photon γ1. γ1 and the energy E of the recoil electron e′ The mapping h is defined as:

[0109] h:E e' →E γ1

[0110] When all reactions are completed, the photomultiplier tube will eventually output an electrical signal v γ , which is obviously a function of the photon energy E received by the photocathode of the photomultiplier tube. Define mapping j to represent:

[0111] j:E→V

[0112] Then the electrical signal v γ Converted into counting signal c γ , after determining the counting period τ, the two are obviously in functional relationship. Define the mapping k to represent:

[0113] k:V→Count

[0114] Based on the above, we can establish the relationship between the photon energy received by the photocathode and the count, which is defined as the mapping

[0115]

[0116] Finally, the photons received by the photomultiplier tube can be divided into two parts: the scattered photons generated directly, and the photons indirectly generated by the excitation and deexcitation of atoms by the recoil electrons. Need to discuss by category:

[0117]

[0118] Take all elements of the form (E,c) to form a set, denoted as Γ:

[0119]

[0120] From its definition, it can be seen that it is the function graph of the sequence pair (energy, count), that is, the spectrum. Considering the energy value method and the measurement error of the instrument, the ideal spectrum should be as follows Figure 4As shown, (E1, E2) is parabolic, and the other parts are close to 0. The image is continuous or piecewise continuous. When the intensity of the incident gamma is large, it should appear as a continuous image. After replacing the energy with the channel address number, the image continuity requirement for the intensity of the incident gamma will be further reduced. In this way, the requirements can generally be met during measurement, and a continuous image is presented.

[0121] The following is an explanation of the effect of Compton scattering inside the crystal on the energy spectrum:

[0122] In the actual measurement process, Figure 5 As shown, the recoil electron e' can excite and de-excite the atom of the material, thereby emitting a photon γ1. The scattered photon γ' may continue to undergo the Compton effect, generating new scattered photons γ" and new recoil electrons e", and this process will be repeated until the photon reaches the photocathode of the photomultiplier tube, or the energy of the particle can no longer support the next reaction. In other words, the incident gamma may undergo several consecutive Compton scatterings in the crystal. Combined with the influence of the scattering angle θ, the photocathode of the photomultiplier tube actually receives a large number of photons of different energies. From the above discussion, it is not difficult to conclude that The formula should not use γ with the same energy, which can be regarded as the same photon for analysis, but a set of photons with different energies A = {γ i1 ,γ i2 ,...}. Each item in this array will affect the graph. To avoid ambiguity, it should be regarded as a high-dimensional variable γ′={γ i1 ,γ i2 ,...}. In the corresponding energy form (E i1 ,E i2 ,...) We discuss this in the formula and get the mapping:

[0123]

[0124] Obviously, each component E i will have an impact on Γ, that is, image Γ. From the above discussion, it is easy to see that its expression is in its corresponding energy range (E i1 ,E i2 ) generates a new parabola and superimposes it on the original image in the same way as waves, which will eventually result in the measurement result being as follows Figure 6 The complex graph shown. Obviously, each element will have similar performance. When superimposed on each other, the high energy segment has a weaker impact due to the relatively small number of elements, and the impact gradually increases as the energy segment decreases, ultimately resulting in the measurement spectrum generally showing an exponential decay trend.

[0125] The following is an explanation of the influence of the crystal's external Compton scattering effect on the energy spectrum:

[0126] In actual production environments, it is also necessary to consider that the Compton scattering effect does not only occur inside the crystal. Figure 7 As shown. γ1, γ2 and γ3 are gamma rays emitted by the reaction of neutrons with formation materials, and γ′1 is the secondary gamma ray produced by effects such as Compton scattering. Neutrons emitted by the neutron source react with formation materials to produce gamma rays. These gamma rays may directly reach the crystal surface, or they may reach the crystal surface after several Compton scattering effects. The secondary gamma rays produced in these reactions may also reach the crystal surface.

[0127] For example, if only the effect of water is considered in the environment, the incident gamma rays received by the crystal may be the gamma rays γ1 and γ2 emitted by neutron bombardment of H atoms or O atoms, or they may be secondary gamma rays γ′1, γ′2, γ″1 and γ″2, etc. generated by one or more Compton scattering of γ. Each reaction will cause the gamma rays to lose energy. Therefore, when only the effect of water is considered in the environment, the energy of the gamma rays that finally reach the crystal surface should be between (124keV, max{γ1, γ2}]. Extending to other elements in the production environment will obviously produce similar results, generating their own intervals (124keV, γ i ], the low energy segments of these intervals will overlap with each other, so as the energy segment decreases, the counting will be more and more significantly affected.

[0128] Consider steps S102A to S102F and step S1031 as solution 1, and consider steps S102G to S102J and steps S1032 to S1034 as solution 2. The test results of solution 1 and solution 2 are compared below:

[0129] The tests were conducted with 37.5mm crystal oil tank and water tank, and 35mm crystal oil tank and water tank. Table 1 and Table 2 are the comparison of the test results. According to the test data, the oil-water contrast ratio increased after the two schemes were reduced, and the increase was about 10%.

[0130] It should be noted that the calculation method of oil-water contrast is: Contrast = (carbon-oxygen ratio of oil layer - carbon-oxygen ratio of water layer) / carbon-oxygen ratio of water layer. Wherein, Contrast represents the oil-water contrast.

[0131] Table 1:

[0132]

[0133] Table 2:

[0134]

[0135] refer to Figure 8 , Fig. 9 , Fig.10 and Fig.11 , taking the 37.5mm crystal oil tank data as an example, the test results of Scheme 1 and Scheme 2 are explained. Figure 8 This is the logarithmic image of the 37.5mm crystal oil tank test data after using Scheme 1 for degradation. Fig. 9 for Figure 8 The corresponding linear image is Fig.10 This is the logarithmic image of the 37.5mm crystal oil tank test data after using Scheme 2 for degradation. Fig.11 for Fig.10 The corresponding linear image.

[0136] The embodiment of the present invention determines the original energy spectrum of the full spectrum logging data; determines the first degraded energy spectrum of the full spectrum logging data based on the original energy spectrum, and the first degraded energy spectrum is used to reduce the influence of the Compton scattering effect on the original energy spectrum; performs energy spectrum degrade processing on the original energy spectrum based on the first degraded energy spectrum to obtain the target energy spectrum of the full spectrum logging data; and obtains the oil-water contrast of the full spectrum logging data based on the target energy spectrum. The energy spectrum degrade processing is performed on the original energy spectrum by the first degraded energy spectrum, so that the accuracy of the photon count of each channel in the energy spectrum is improved, so that the influence of the Compton scattering effect on the oil-water contrast accuracy of the full spectrum logging data is reduced.

[0137] Based on the same inventive concept, Fig.12 As shown, an embodiment of the present invention provides an oil-water contrast acquisition device 10 for full spectrum logging data, including: an original determination unit 110, used to determine the original energy spectrum of the full spectrum logging data; a degradation determination unit 120, used to determine a first degradation energy spectrum of the full spectrum logging data based on the original energy spectrum, the first degradation energy spectrum is used to reduce the influence of the Compton scattering effect on the original energy spectrum; a target determination unit 130, used to perform energy spectrum degradation processing on the original energy spectrum based on the first degradation energy spectrum to obtain a target energy spectrum of the full spectrum logging data; a contrast acquisition unit 140, used to obtain the oil-water contrast of the full spectrum logging data based on the target energy spectrum.

[0138] It can be understood that the degradation determination unit 120 includes: a slope determination subunit, which is used to determine the second slope based on the input first slope and the amplification factor; an energy window determination subunit, which is used to determine the first energy window and the second energy window of the original energy spectrum; a change rate determination subunit, which is used to determine the first change acceleration of the count in the first energy window, and determine the second change acceleration of the count in the second energy window; a second degradation determination subunit, which is used to determine the second degradation energy spectrum based on the second slope and the first change acceleration; a third degradation determination subunit, which is used to determine the third degradation energy spectrum based on the first slope and the second change acceleration; and a comparison subunit, which is used to compare the photon count of each channel address of the second degradation energy spectrum with the photon count of the corresponding channel address in the third degradation energy spectrum, and obtain the first degradation energy spectrum based on the larger photon count.

[0139] It can be understood that the target determination unit 130 includes: a first target acquisition subunit, which is used to subtract the photon count of each channel address in the original energy spectrum from the photon count of the corresponding channel address in the first degraded energy spectrum to obtain the target energy spectrum.

[0140] It can be understood that the energy window determination subunit is specifically used to: obtain the target energy window and hydrogen peak of the original energy spectrum; and divide the target energy window into a first energy window and a second energy window based on the hydrogen peak.

[0141] It can be understood that the change rate determination subunit is specifically used to: determine the first change acceleration of the count in the first energy window, including: obtaining the first coefficient, the first photon count and the first track address number of the first energy window; based on the first coefficient, the first photon count and the first track address number, determine the first change acceleration of the count in the first energy window; determine the second change acceleration of the count in the second energy window, including: obtaining the second coefficient, the second photon count and the second track address number of the second energy window; based on the second coefficient, the second photon count and the second track address number, determine the second change acceleration of the count in the second energy window.

[0142] It can be understood that the backoff determination unit 120 also includes: a logarithmic transformation subunit, which is used to perform a logarithmic transformation on the original energy spectrum to obtain a first energy spectrum; a straight line determination subunit, which is used to determine an approximate straight line of the first energy spectrum; an information acquisition subunit, which is used to obtain the straight line slope and straight line intercept of the approximate straight line; and a first backoff determination subunit, which is used to determine the first backoff energy spectrum based on the straight line slope, the straight line intercept and the input compensation value.

[0143] It can be understood that the target determination unit 130 also includes: a fourth de-escalation determination subunit, which is used to perform an exponential transformation on the first de-escalation energy spectrum to obtain a fourth de-escalation energy spectrum; a difference subunit, which is used to subtract the photon count of each channel address in the original energy spectrum from the photon count of the corresponding channel address in the fourth de-escalation energy spectrum to obtain a second energy spectrum; and a second target acquisition subunit, which is used to compare the photon count of each channel address in the original energy spectrum with the photon count of the corresponding channel address in the second energy spectrum, and obtain the target energy spectrum based on the smaller photon count.

[0144] It can be understood that the straight line determination subunit is specifically used to: obtain a first channel address and a second channel address; obtain a first photon count corresponding to the first channel address on the first energy spectrum, and a second photon count corresponding to the second channel address on the first energy spectrum; and obtain an approximate straight line based on the first channel address, the first photon count, the second channel address, and the second photon count.

[0145] It should be understood that more implementation details of the oil-water contrast acquisition device 10 for full spectrum logging data in the embodiment of the present invention refer to the above-mentioned oil-water contrast acquisition method for full spectrum logging data, and for the sake of brevity of the specification, they are not repeated here.

[0146] Based on the same inventive concept, an embodiment of the present invention further provides an electronic device, such as Fig.13 As shown, it includes a memory 1304, a processor 1302, and a computer program stored in the memory 1304 and executable on the processor 1302. The processor 1302 executes the program to implement the steps described in any implementation of the method for obtaining oil-water contrast of full spectrum logging data.

[0147] Among them, Fig.13 In the embodiment of the present invention, a bus architecture (represented by bus 1300) is shown, which may include any number of interconnected buses and bridges, and bus 1300 links various circuits including one or more processors represented by processor 1302 and memory represented by memory 1304. Bus 1300 may also link various other circuits such as peripherals, voltage regulators, and power management circuits, which are well known in the art and are therefore not further described herein. Bus interface 1305 provides an interface between bus 1300 and receiver 1301 and transmitter 1303. Receiver 1301 and transmitter 1303 may be the same element, namely a transceiver, providing a unit for communicating with various other devices over a transmission medium. Processor 1302 is responsible for managing bus 1300 and general processing, while memory 1304 may be used to store data used by processor 1302 when performing operations.

[0148] The embodiment of the present invention determines the original energy spectrum of the full spectrum logging data; determines the first degraded energy spectrum of the full spectrum logging data based on the original energy spectrum, and the first degraded energy spectrum is used to reduce the influence of the Compton scattering effect on the original energy spectrum; performs energy spectrum degrade processing on the original energy spectrum based on the first degraded energy spectrum to obtain the target energy spectrum of the full spectrum logging data; and obtains the oil-water contrast of the full spectrum logging data based on the target energy spectrum. The energy spectrum degrade processing is performed on the original energy spectrum by the first degraded energy spectrum, so that the accuracy of the photon count of each channel in the energy spectrum is improved, so that the influence of the Compton scattering effect on the oil-water contrast accuracy of the full spectrum logging data is reduced.

[0149] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored as one or more instructions or codes on a computer-readable medium or transmitted via a computer-readable medium. Other examples and implementations are within the scope and spirit of the present invention and the appended claims. For example, due to the nature of software, the functions described above may be implemented using software executed by a processor, hardware, firmware, hard wiring, or a combination of any of these. In addition, each functional unit may be integrated into a processing unit, each unit may exist physically separately, or two or more units may be integrated into one unit.

[0150] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of the units can be a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0151] The units described as separate components may or may not be physically separated, and the components of the control device may or may not be physical units, that is, they may be located in one place or distributed in multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0152] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk and other media that can store program codes.

[0153] The above description is only an embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the claims of the present invention.

Claims

1. A method for obtaining oil-water contrast of full spectrum logging data, characterized in that: include: Determining the original energy spectrum of the full spectrum logging data; Based on the original energy spectrum, determining a first degraded energy spectrum of the full spectrum logging data, wherein the first degraded energy spectrum is used to reduce the influence of Compton scattering effect on the original energy spectrum; Performing energy spectrum degradation processing on the original energy spectrum based on the first degradation energy spectrum to obtain a target energy spectrum of the full spectrum logging data; Based on the target energy spectrum, the oil-water contrast of the full spectrum logging data is obtained.

2. The method for obtaining oil-water contrast of full spectrum logging data according to claim 1, characterized in that: The step of determining a first degradation energy spectrum of the full spectrum logging data based on the original energy spectrum includes: Determine a second slope based on the input first slope and a magnification factor; Determine a first energy window and a second energy window of the original energy spectrum; Determining a first change acceleration of counts in the first energy window, and determining a second change acceleration of counts in the second energy window; determining a second degradation energy spectrum based on the second slope and the first change acceleration; determining a third degradation energy spectrum based on the first slope and the second change acceleration; The photon count of each channel address in the second de-escalation energy spectrum is compared with the photon count of the corresponding channel address in the third de-escalation energy spectrum, and the first de-escalation energy spectrum is obtained based on the larger photon count.

3. The method for obtaining oil-water contrast of full spectrum logging data according to claim 2, characterized in that: The performing energy spectrum degradation processing on the original energy spectrum based on the first degradation energy spectrum to obtain the target energy spectrum of the full spectrum logging data includes: The target energy spectrum is obtained by subtracting the photon count of each channel in the original energy spectrum from the photon count of the corresponding channel in the first degraded energy spectrum.

4. The method for obtaining oil-water contrast of full spectrum logging data according to claim 2, characterized in that: Determining the first energy window and the second energy window of the original energy spectrum includes: Acquiring a target energy window and a hydrogen peak of the original energy spectrum; The target energy window is divided into the first energy window and the second energy window based on the hydrogen peak.

5. The method for obtaining oil-water contrast of full spectrum logging data according to claim 2, characterized in that: The determining a first change acceleration of counts in the first energy window comprises: Acquire a first coefficient, a first photon count sum of the first energy window, and a first channel address number of the first energy window; determining a first change acceleration of counts in the first energy window based on the first coefficient, the first photon count and the first track address number; The determining a second change acceleration of counts in the second energy window comprises: Acquire a second coefficient, a second photon count sum of the second energy window, and a second channel address number of the second energy window; A second acceleration of change of counts in the second energy window is determined based on the second coefficient, the second photon count sum, and the second track address number.

6. The method for obtaining oil-water contrast of full spectrum logging data according to claim 1, characterized in that: The step of determining a first degradation energy spectrum of the full spectrum logging data based on the original energy spectrum includes: Performing logarithmic transformation on the original energy spectrum to obtain a first energy spectrum; determining an approximate straight line of the first energy spectrum; Obtaining the linear slope and linear intercept of the approximate straight line; The first degradation energy spectrum is determined based on the straight line slope, the straight line intercept and the input compensation value.

7. The method for obtaining oil-water contrast of full spectrum logging data according to claim 6, characterized in that: The performing energy spectrum degradation processing on the original energy spectrum based on the first degradation energy spectrum to obtain the target energy spectrum of the full spectrum logging data includes: performing an exponential transformation on the first decay energy spectrum to obtain a fourth decay energy spectrum; Subtract the photon count of each channel address in the original energy spectrum from the photon count of the corresponding channel address in the fourth degraded energy spectrum to obtain a second energy spectrum; The photon count of each channel address in the original energy spectrum is compared with the photon count of the corresponding channel address in the second energy spectrum, and the target energy spectrum is obtained based on the smaller photon count.

8. The method for obtaining oil-water contrast of full spectrum logging data according to claim 6, characterized in that: The determining of the approximate straight line of the first energy spectrum comprises: Get the first address and the second address; Acquire a first photon count corresponding to the first address on the first energy spectrum, and a second photon count corresponding to the second address on the first energy spectrum; The approximate straight line is obtained based on the first track address, the first photon count, the second track address, and the second photon count.

9. A device for acquiring oil-water contrast of full spectrum logging data, characterized in that: include: An original determination unit, used to determine the original energy spectrum of the full spectrum logging data; A degradation determination unit, configured to determine a first degradation energy spectrum of the full spectrum logging data based on the original energy spectrum, wherein the first degradation energy spectrum is used to reduce the influence of Compton scattering effect on the original energy spectrum; a target determination unit, configured to perform energy spectrum degradation processing on the original energy spectrum based on the first degradation energy spectrum, so as to obtain a target energy spectrum of the full spectrum logging data; A contrast acquisition unit is used to acquire the oil-water contrast of the full spectrum logging data based on the target energy spectrum.

10. An electronic device, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method according to any one of claims 1 to 8 when executing the computer program.

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