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

Abstract

The application discloses a kind of oil-water contrast acquisition method, device and equipment of full spectrum logging data, the method comprises: determining the original energy spectrum of full spectrum logging data;Based on the original energy spectrum, determine the first energy spectrum of full spectrum logging data, the first energy spectrum is used to reduce the influence of Compton scattering effect on original energy spectrum;Based on the first energy spectrum of original energy spectrum, energy spectrum is reduced to handle, to obtain the target energy spectrum of full spectrum logging data;Based on the target energy spectrum, the oil-water contrast of full spectrum logging data is acquired.The application solves the technical problem that Compton scattering effect has great influence on the oil-water contrast precision of full spectrum logging data.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of mineral resources exploration, and particularly relates to a method and device for obtaining oil-water contrast of full-spectrum logging data. BACKGROUND

[0002] The use of a pulsed neutron source to measure formation matrix and fluid parameters has a wide range of applications in the field of mineral resource exploration such as oil, gas, coal, and metals. The pulsed neutron source is used to measure and analyze the content of various elements in rocks, coal, or other mineral deposits, as well as the content of oil and gas in oil and gas wells. Through the reaction of pulsed neutron flow with the material in the formation, the non-elastic gamma, capture gamma, and activated gamma generated in the reaction are recorded to obtain the energy spectrum, and ultimately the oil-water contrast of full-spectrum logging data is obtained. In this process, the returned gamma rays, due to Compton scattering effects, excite atoms in the crystal to release photons, which after several reactions reach the photocathode of the photomultiplier tube and are ultimately converted into electrical pulse signals corresponding to the energy. The energy resolution and statistical fluctuations of the scintillation counter composed of the crystal and the photomultiplier tube in the measurement of gamma rays result in a large error in the oil-water contrast of the obtained full-spectrum logging data, affecting subsequent well completion and oilfield development. Therefore, the Compton scattering effect has a significant impact on the accuracy of the oil-water contrast of full-spectrum logging data, which is a technical problem that needs to be solved urgently. SUMMARY

[0003] The present application provides a method and device for obtaining oil-water contrast of full-spectrum logging data, which solves the technical problem of the Compton scattering effect having a significant impact on the accuracy of the oil-water contrast of full-spectrum logging data.

[0004] In a first aspect, the present application provides a method for obtaining oil-water contrast of full-spectrum logging data, comprising: determining the original energy spectrum of the full-spectrum logging data; based on the original energy spectrum, determining the first descending energy spectrum of the full-spectrum logging data, which is used to reduce the impact of Compton scattering effect on the original energy spectrum; performing energy spectrum descending processing on the original energy spectrum based on the first descending energy spectrum to obtain the target energy spectrum of the full-spectrum logging data; and based on the target energy spectrum, obtaining the oil-water contrast of the full-spectrum logging data.

[0005] In some embodiments of the first aspect of the present application, the determining the first roll-off energy spectrum of the full spectrum logging data based on the original energy spectrum comprises: determining a second slope based on an input first slope and an amplification coefficient; determining 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 a second change acceleration of counts in the second energy window; determining a second roll-off energy spectrum based on the second slope and the first change acceleration; determining a third roll-off energy spectrum based on the first slope and the second change acceleration; comparing photon counts of each trace address in the second roll-off energy spectrum with photon counts of corresponding trace addresses in the third roll-off energy spectrum, and obtaining the first roll-off energy spectrum based on the larger photon counts.

[0006] In some embodiments of the first aspect of the present application, the energy spectrum roll-off processing of the original energy spectrum based on the first roll-off energy spectrum to obtain a target energy spectrum of the full spectrum logging data comprises: subtracting photon counts of each trace address in the original energy spectrum from photon counts of corresponding trace addresses in the first roll-off energy spectrum to obtain the target energy spectrum.

[0007] In some embodiments of the first aspect of the present application, the determining the first energy window and the second energy window of the original energy spectrum comprises: 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 some embodiments of the first aspect of the present application, the determining the first change acceleration of counts in the first energy window comprises: obtaining a first coefficient, a first photon count of the first energy window, and a first number of traces of the first energy window; and determining the first change acceleration of counts in the first energy window based on the first coefficient, the first photon count, and the first number of traces; and the determining the second change acceleration of counts in the second energy window comprises: obtaining a second coefficient, a second photon count of the second energy window, and a second number of traces of the second energy window; and determining the second change acceleration of counts in the second energy window based on the second coefficient, the second photon count, and the second number of traces.

[0009] In some embodiments of the first aspect of the present application, the determining the first roll-off energy spectrum of the full spectrum logging data based on the original energy spectrum comprises: 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 a straight line slope and a straight line intercept of the approximate straight line; and determining the first roll-off energy spectrum based on the straight line slope, the straight line intercept, and an input compensation value.

[0010] In some embodiments of the first aspect of the present application, the energy spectrum degrading processing of the original energy spectrum based on the first degraded energy spectrum to obtain the target energy spectrum of the full spectrum logging data comprises: performing exponential transformation on the first degraded energy spectrum to obtain a fourth degraded energy spectrum; subtracting the photon count of each trace address of the original energy spectrum from the photon count of the corresponding trace address in the fourth degraded energy spectrum to obtain a second energy spectrum; comparing the photon count of each trace address of the original energy spectrum with the photon count of the corresponding trace address in the second energy spectrum, and obtaining the target energy spectrum based on the smaller photon count.

[0011] In some embodiments of the first aspect of the present application, the determination of the approximate straight line of the first energy spectrum comprises: obtaining a first trace address and a second trace address; obtaining a first photon count corresponding to the first trace address on the first energy spectrum and a second photon count corresponding to the second trace address on the first energy spectrum; and obtaining the approximate straight line based on the first trace address, the first photon count, the second trace address and the second photon count.

[0012] In the second aspect, the embodiments of the present application provide a device for obtaining oil-water contrast of full spectrum logging data, which comprises: an original determination unit configured to determine an original energy spectrum of the full spectrum logging data; a degradation determination unit configured to determine a first degraded energy spectrum of the full spectrum logging data based on the original energy spectrum, the first degraded energy spectrum being 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 of the original energy spectrum based on the first degraded energy spectrum to obtain a target energy spectrum of the full spectrum logging data; and a contrast obtaining unit configured to obtain oil-water contrast of the full spectrum logging data based on the target energy spectrum.

[0013] In the third aspect, the embodiments of the present application provide an electronic device, which comprises a memory, a processor, and a computer program stored in the memory and capable of running on the processor, and the processor implements the method of any one of the first aspect when executing the computer program.

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

[0015] The embodiment of the present application determines the original energy spectrum of the full spectrum logging data; determines the first descending energy spectrum of the full spectrum logging data based on the original energy spectrum, the first descending energy spectrum is used to reduce the influence of the Compton scattering effect on the original energy spectrum; performs energy spectrum descending processing on the original energy spectrum based on the first descending 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 descending processing on the original energy spectrum through the first descending energy spectrum improves the accuracy of the photon count of each trace in the energy spectrum, so that the influence of the Compton scattering effect on the oil-water contrast precision of the full spectrum logging data is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0017] Figure 1 The flow chart of the oil-water contrast obtaining method of the full spectrum logging data in the embodiment of the present application;

[0018] Figure 2 The schematic diagram of the advantage zone distribution of the three effects of photons in the embodiment of the present application;

[0019] Figure 3 The reaction schematic diagram of the Compton scattering in the embodiment of the present application;

[0020] Figure 4 The ideal graph of the energy and the photon count in the embodiment of the present application;

[0021] Figure 5 The schematic diagram of the Compton scattering in the actual measurement process in the embodiment of the present application;

[0022] Figure 6 The actual measurement graph of the energy and the photon count in the embodiment of the present application;

[0023] Figure 7 The schematic diagram of the crystal receiving gamma rays in the working environment in the embodiment of the present application;

[0024] Figure 8 The log image after descending of the 37.5mm crystal oil tank test data using scheme one in the embodiment of the present application;

[0025] Figure 9 The Figure 8 The corresponding linear image;

[0026] Figure 10A log image after the second scheme of decline is used for the test data of the 37.5mm crystal oil tank in the embodiment of the present application;

[0027] Figure 11 For Figure 10 A corresponding linear image;

[0028] Figure 12 For the functional module diagram of the oil-water contrast acquisition device of the full-spectrum logging data in the embodiment of the present application;

[0029] Figure 13 For the structural schematic diagram of the electronic device in the embodiment of the present application. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative work are within the protection scope of the present application.

[0031] In the present application, the description such as "first", "second" and the like is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In addition, the technical solutions of various embodiments can be combined with each other, but it must be based on the fact that a person of ordinary skill in the art can realize it, and when the combination of technical solutions appears to be contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is not within the protection scope required by the present application.

[0032] The embodiment of the present application provides a method for obtaining oil-water contrast of full-spectrum logging data, as shown in the figure, the method comprises the following steps S101-S104: Figure 1

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

[0034] It can be understood that the first energy spectrum of the full-spectrum logging data can be obtained by reacting the pulsed neutron flow with the full-spectrum logging data.

[0035] S102: Based on the original energy spectrum, determine the first decline energy spectrum of the full-spectrum logging data, and the first decline energy spectrum is used to reduce the influence of Compton scattering effect on the original energy spectrum.

[0036] It can be understood that the determination of the first decline energy spectrum of the full-spectrum logging data based on the original energy spectrum can include the following steps S102A-S102F:​

[0037] S102A: determining a second slope based on the input first slope and an amplification coefficient.

[0038] It can be understood that the product of the first slope and the amplification coefficient can be directly taken as the second slope, wherein the amplification coefficient and the first slope are empirical values. For example, the amplification coefficient can be taken as 1.5. The first slope can be taken as 2.2.

[0039] S102B: determining a first energy window and a 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 can include: 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.

[0041] S102C: 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.

[0042] It can be understood that determining the first change acceleration of counts in the first energy window can include: obtaining a first coefficient, a first photon count sum of the first energy window, and a first channel number of the first energy window; and determining the first change acceleration of counts in the first energy window based on the first coefficient, the first photon count sum, and the first channel number. It should be noted that the first channel number of the first energy window refers to the number of channels of the first energy window. For example, the first energy window includes channel 7, channel 8, and channel 9, and the first channel 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 channels of the first energy window. For example, the first energy window includes channel 7, channel 8, and channel 9, channel 7 contains a photons, channel 8 contains b photons, and channel 9 contains c photons, and 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 counts in the second energy window can include: obtaining a second coefficient, a second photon count sum of the second energy window, and a second channel number of the second energy window; and determining the second change acceleration of counts in the second energy window based on the second coefficient, the second photon count sum, and the second channel number. It should be noted that the second channel number of the second energy window refers to the number of channels of the second energy window. For example, the second energy window includes channel 4, channel 5, and channel 6, and the second channel 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 channels of the second energy window. For example, the second energy window includes channel 4, channel 5, and channel 6, channel 4 contains a photons, channel 5 contains b photons, and channel 6 contains c photons, and 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 embodiments, the first varying acceleration can be calculated by the following formula:

[0045]

[0046] wherein Sum1 is the first varying acceleration, a is a first coefficient, b is a first photon count sum, and c is a first channel number. Sum2 is the second varying acceleration, d is a second coefficient, e is a second photon count sum, and f is a second channel number. It should be noted that Sum1 and Sum2 also represent the second derivative of the photon count with respect to the channel number, and the physical meaning of Sum1 and Sum2 is the acceleration of the photon count in each energy segment with respect to the channel number corresponding to the energy segment. The first coefficient and the second coefficient are empirical coefficients for adjusting the trend of the spectrum, and the physical meaning thereof is the average photon density in the corresponding energy window.

[0047] S102D: determining a second falling energy spectrum based on the second slope and the first varying acceleration.

[0048] S102E: determining a third falling energy spectrum based on the first slope and the second varying acceleration.

[0049] Specifically, the second falling energy spectrum can be represented by the following formula:

[0050]

[0051] wherein data2(i) represents the second falling energy spectrum, Sum1 is the first varying acceleration, and k2 is the second slope. data3(i) represents the third falling energy spectrum, Sum2 is the second varying acceleration, and k1 is the first slope. It should be noted that the channel number of the spectrum has 256 in total, and i represents the i-th channel number.

[0052] S102F: comparing the photon count of each channel number of the second falling energy spectrum with the photon count of the corresponding channel number in the third falling energy spectrum, and obtaining the first falling energy spectrum based on the larger photon count.

[0053] Specifically, the first falling energy spectrum can be represented by the following formula:

[0054]

[0055] wherein data1(i) represents the first falling energy spectrum. data2(i) represents the second falling energy spectrum. data3(i) represents the third falling energy spectrum.

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

[0057] S102G: Logarithmically transforming the original energy spectrum to obtain a first energy spectrum.

[0058] It can be understood that the logarithmic transformation of the original energy spectrum can be taking the logarithm with base 10 of the photon counts in the original energy spectrum to obtain the first energy spectrum.

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

[0060] In some embodiments, the determining of the approximate straight line of the first energy spectrum comprises: 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. It can be understood that a first point on the first energy spectrum can be determined based on the first channel address and the first photon count, a second point on the first energy spectrum can be determined based on the second channel address and the second photon count, and the approximate straight line can be obtained by connecting the first point and the second point. It should be noted that the first channel address can be 60 and the second channel address can be 68.

[0061] S102I: Obtaining a straight line slope and a straight line intercept of the approximate straight line.

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

[0063] Specifically, the first falling energy spectrum can be represented by the following formula:

[0064] data1(i) = i x k + b1 + b2;

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

[0066] S103: Performing energy spectrum falling processing on the original energy spectrum based on the first falling 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-S102J or steps S102A-S102F to obtain the first falling energy spectrum, but the first falling energy spectrum obtained by steps S102G-S102J and steps S102A-S102F is not the same, so the energy spectrum falling processing in step S103 also exists difference for the two different cases, which will be described respectively.

[0068] If the step S102 specifically comprises the steps S102A-S102F, corresponding thereto, the step S103 can comprise a step S1031 of subtracting the photon counts of each channel address of the original energy spectrum from the photon counts of the corresponding channel address in the first degraded energy spectrum to obtain the target energy spectrum.

[0069] The target energy spectrum can be represented by the following formula:

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

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

[0072] It can be understood that, for the steps S102G-S102J, the step S103 can comprise steps S1032-S1034:

[0073] The step S1032 comprises performing exponential transformation on the first degraded energy spectrum to obtain a fourth degraded 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 can be: taking the exponential of 10 of the photon counts of the first degraded energy spectrum to obtain the fourth degraded energy spectrum.

[0075] The step S1033 comprises subtracting the photon counts of each channel address of the original energy spectrum from the photon counts of the corresponding channel address in the fourth degraded energy spectrum to obtain a second energy spectrum.

[0076] The step S1034 comprises comparing the photon counts of each channel address of the original energy spectrum with the photon counts of the corresponding channel address in the second energy spectrum, and obtaining the target energy spectrum based on the smaller photon counts.

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

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

[0079]

[0080] 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 is reduced by the above steps S102G-S102J and steps S1032-S1034, and the count of the reduced energy spectrum in the low energy section will be reduced by a large part, and with the increase of energy, the data will be reduced, and gradually tend to 0 in the high energy section. The overall trend is approximately exponential function. This is in line with the actual data law. In addition, the default values of the above parameters will also be different according to the type of spectrum.

[0082] S104: Based on the target energy spectrum, the oil-water contrast of the full spectrum logging data is obtained.

[0083] It should be noted that the image of the photon count of the original energy spectrum decays exponentially, which is caused by the instrument background, count accumulation, Compton scattering effect and other effects. Therefore, a reduced energy spectrum simulation conforming to the exponential law can be made, and the original energy spectrum is reduced to reduce the influence. The influence of Compton effect is approximately exponential function, and the image after taking logarithm is approximately linear function. Based on this, two ways are provided, steps S102A-S102F segment the energy window based on the hydrogen peak, calculate respectively and then synthesize to obtain the reduced energy spectrum; steps S102G-S102J analyze the logarithmic image of the data, specify the starting and ending channel addresses and compensation value, and draw the reduced energy spectrum. The influence of the two schemes on the results of each data such as carbon-oxygen ratio and silicon-calcium ratio is not the same, and the user can choose according to the use scene.

[0084] It should be noted that due to Compton scattering, the data of the energy spectrum fluctuates, and the Compton scattering effect will be explained below, and the principle of its influence on the energy spectrum will be explained:

[0085] Reference Figure 2 From the distribution of the three effects of photons, it can be seen that Compton effect is an important reason for the decline of spectrum measurement accuracy. The collision between gamma photons and outer electrons of atoms makes the electrons escape from the binding energy of the atoms to become recoil electrons. In this process, the incident photons lose energy and change in frequency, forming scattered photons. The incident photons, electrons and scattered photons are regarded as a system to describe this process:

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

[0087] E e and E e′ represent the energy of the electron before and after the collision, respectively, E γ and E γ′respectively, and the Compton scattering mainly occurs in the outer electrons, which makes the binding energy required for the electrons to be detached from the atom much smaller than the energies of other particles involved in the discussion, so it is ignored. It should be noted that the discussion of the Compton effect assumes that the electron is stationary. Reference Figure 3 Figure 3 is a schematic diagram of the reaction of Compton scattering.

[0088] First, for the outer electrons, it is easy to know from the structure of the atom that part of the photons may collide with the inner electrons in the reaction. However, since the inner bound electrons are combined with the atom more tightly, it is essentially equivalent to colliding with the atom itself, so in the following discussion, the atomic rest mass should be used instead when calculating, which will result in a change in wavelength that is almost 0, which does not need to be discussed, which is the reason why Compton scattering is mainly aimed at outer electrons that can be approximated as free.

[0089] Second, for the stationary electron, in the Compton effect, the assumption is made that the electron is stationary. In fact, the electron is certainly not stationary. Therefore, m0 used in the calculation of E e Since this article is a qualitative discussion, this will not affect the results. When the photon undergoes Compton scattering inside the crystal, the energy and momentum of the system are conserved, combined with the cosine theorem:

[0090]

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

[0092] E γ = hv

[0093] E γ' = hv'

[0094]

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

[0096]

[0097] where v represents the recoil velocity of the electron, and v and v' represent the frequencies of the incident photon and the scattered photon, respectively. Substitute the above cosine theorem and get the Compton scattering formula after rearrangement:​​

[0098]

[0099] After the transformation, further use the angle θ and the energy E γ of the incident gamma to express the energy of the recoil electron and the scattered photon. Let E e′ represent the energy of the recoil electron, and E γ′ represent the energy of the scattered photon. Naturally, define the mapping f and the mapping g to represent their relationship with the angle θ and the incident gamma energy E γ :

[0100]

[0101]

[0102] For any given element, the energy of the characteristic gamma E γ is uniquely determined, and at this time, the above formulas can be derived respectively, E e′ and E γ′ will be uniquely determined by θ. That is, for any element X, the mapping relationship between the energy of the recoil electron or the 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 [0, 2π] interval, but must be contained therein, and is a continuous or piecewise continuous interval Therefore, the value ranges U(E e′ ) and U(E γ′ ) of E e′ and 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] Again, focus on the recoil electron generated by the reaction, the recoil electron makes the atom excitation-deexcitation, and in the process, the photon γ1 is emitted. This process is not described in detail here, only to make clear that the energy E γ1 of the photon γ1 is a function of the energy E e′ of the recoil electron. Define the mapping h to represent:

[0109] h: E e' → E γ1

[0110] When all the reactions are completed, the photomultiplier 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. Define the mapping j to represent:

[0111] j: E→ V

[0112] Then convert the electrical signal v γ into a count signal c γ , after determining the counting period τ, the two are obviously a function. Define the mapping k to represent:

[0113] k: V→ Count

[0114] In summary, the relationship between the photocathode received photon energy and the count can be established, defined as the mapping

[0115]

[0116] Finally, the photomultiplier receives the photon, only discussing its last reaction, its source can be divided into two parts, the direct generation of scattered photons, or indirectly generated by the recoil electron atom excitation-deexcitation photons, mapping Need to be classified:

[0117]

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

[0119]

[0120] From its definition, it is the function image of the ordered pair (energy, count), that is, the atlas. Considering the way energy is taken and the measurement error of the instrument, the ideal atlas should be like Figure 4As shown in (E1, E2) is parabolic, other parts tend to 0, the image continuous or piecewise continuous, when the intensity of the incident gamma is larger, should be a continuous image, the image continuous to replace the energy channel address number of incident gamma intensity requirements will be further reduced. Thus in the measurement can generally meet the requirements, continuous image.

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

[0122] In the actual measurement process, as shown in Figure 5 , the recoil electron e' will make the material atom excited-deexcited to emit photons γ1, scattered photons γ' may continue to have Compton effect, produce new scattered photons γ" and new recoil electrons e", so as to repeat, until the photons reach the photocathode of the photomultiplier tube, or the energy of the particles can no longer support the next reaction. That is to say, the incident gamma may continuously undergo several times of Compton scattering in the crystal, combined with the influence of scattering angle θ, the photocathode of the photomultiplier tube actually receives a large number of photons with different energies. From the above discussion, it is not difficult to obtain that The formula should not use γ with the same energy, which can be regarded as the same photon for analysis, but needs to bring in a set of photons A = {γ i1 , γ i2 ,...}. Each item of this array will have an impact on the graph, and should be regarded as a high-dimensional variable γ' = {γ i1 , γ i2 ,...} to avoid ambiguity. The corresponding energy form (E i1 , E i2 ,...) is brought into the formula for discussion, and the mapping is obtained:

[0123]

[0124] Obviously, each component E i will affect Γ, that is, the image Γ. From the above discussion, it is easy to know that its form of expression is to produce a new parabola in its corresponding energy segment (E i1 , E i2 ) and superimpose it into the original graph, and the superimposition method is the same as the superposition of waves, which will eventually result in the measured results showing a complex graph as shown in Figure 6 . Obviously, each element will have a similar performance. Under mutual superposition, the high-energy segment has relatively weak influence due to fewer elements, and the influence gradually increases as the energy segment decreases, eventually leading to the measured spectrum generally showing an exponential decay trend.

[0125] The following describes the effect of Compton scattering outside the crystal on the energy spectrum:

[0126] In actual production environment, Compton scattering effect does not only occur inside the crystal. Referring to Fig. 1, the gamma rays emitted by the neutron source are shown. γ1, γ2 and γ3 are gamma rays emitted by the reaction between the neutrons and the formation material, and γ'1 is the secondary gamma ray generated by Compton scattering effect. The neutron source emits neutrons which react with the formation material to generate gamma rays. These gamma rays can directly reach the surface of the crystal, or reach the surface of the crystal after several times of Compton scattering effect. The secondary gamma rays generated in these reaction processes can also reach the surface of the crystal. Figure 7

[0127] For example, if only the influence of water is considered in the environment, the incident gamma rays received by the crystal can be the gamma rays γ1 and γ2 emitted by the bombardment of H atoms or O atoms by the neutrons, or the secondary gamma rays γ'1, γ'2, γ"1 and γ"2 generated by one or more times of Compton scattering effect of γ. Each reaction will cause the gamma rays to lose energy. Therefore, when only the influence of water is considered in the environment, the energy of the gamma rays finally reaching the surface of the crystal should be between [124 keV, max{γ1, γ2}]. When extended to other elements in the production environment, similar results will obviously be generated, and respective intervals (124 keV, γ i ] will be generated. The low-energy section of these intervals will overlap with each other, and therefore, as the energy section decreases, the influence on the counting will become more and more obvious.

[0128] The steps S102A-S102F and the step S1031 are regarded as scheme one, and the steps S102G-S102J and the steps S1032-S1034 are regarded as scheme two. The test results of scheme one and scheme two are compared as follows:

[0129] The 37.5 mm crystal oil tank and the water tank, and the 35 mm crystal oil tank and the water tank are respectively tested. Table 1 and Table 2 are the comparison of the test results. According to the test data, after the degradation of the two schemes, the oil-water contrast is increased by about 10%.

[0130] It should be noted that the calculation method of the oil-water contrast is as follows: 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] Reference Figure 8 , Figure 9 ,​Figure 10 and Figure 11 Taking the data from a 37.5mm crystal oil tank as an example, the test results of Scheme 1 and Scheme 2 will be explained. Figure 8 The logarithmic graph of the 37.5mm crystal oil tank after the degradation of Scheme 1 was used. Figure 9 for Figure 8 The corresponding linear image, Figure 10 The logarithmic graph of the 37.5mm crystal oil tank after degradation was used for the test data. Figure 11 for Figure 10 The corresponding linear graph.

[0136] This invention describes a method for determining the original energy spectrum of full-spectrum logging data. Based on the original energy spectrum, a first reduced energy spectrum is determined, used to reduce the impact of Compton scattering on the original energy spectrum. The original energy spectrum is then subjected to energy spectrum reduction processing based on the first reduced energy spectrum to obtain the target energy spectrum of the full-spectrum logging data. Finally, the oil-water contrast ratio of the full-spectrum logging data is obtained based on the target energy spectrum. By performing energy spectrum reduction processing on the original energy spectrum using the first reduced energy spectrum, the accuracy of photon counting at each pass in the energy spectrum is improved, thus reducing the impact of Compton scattering on the accuracy of the oil-water contrast ratio of the full-spectrum logging data.

[0137] Based on the same inventive concept, and referring to Figure 12 As shown, this embodiment of the invention provides an oil-water contrast acquisition device 10 for full-spectrum logging data, comprising: an original determination unit 110 for determining the original energy spectrum of the full-spectrum logging data; a degradation determination unit 120 for determining 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 the Compton scattering effect on the original energy spectrum; a target determination unit 130 for 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 a contrast acquisition unit 140 for acquiring 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 comprises: a slope determination subunit configured to determine a second slope based on the input first slope and an amplification coefficient; a window determination subunit configured to determine a first energy window and a second energy window of the original energy spectrum; a rate of change determination subunit configured to determine a first rate of change of counts in the first energy window and a second rate of change of counts in the second energy window; a second degradation determination subunit configured to determine a second degradation energy spectrum based on the second slope and the first rate of change; a third degradation determination subunit configured to determine a third degradation energy spectrum based on the first slope and the second rate of change; and a comparison subunit configured to compare the photon counts of each channel address in the second degradation energy spectrum with the photon counts of the corresponding channel address in the third degradation energy spectrum, and obtain the first degradation energy spectrum based on the larger photon counts.

[0139] It can be understood that the target determination unit 130 comprises a first target acquisition subunit configured to subtract the photon counts of each channel address in the original energy spectrum from the photon counts of the corresponding channel address in the first degradation energy spectrum to obtain a target energy spectrum.

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

[0141] It can be understood that the rate of change determination subunit is specifically configured to: determine the first rate of change of counts in the first energy window, comprising: acquiring a first coefficient, a first photon count of the first energy window, and a first number of channel addresses of the first energy window; and determining the first rate of change of counts in the first energy window based on the first coefficient, the first photon count, and the first number of channel addresses; and determine the second rate of change of counts in the second energy window, comprising: acquiring a second coefficient, a second photon count of the second energy window, and a second number of channel addresses of the second energy window; and determining the second rate of change of counts in the second energy window based on the second coefficient, the second photon count, and the second number of channel addresses.

[0142] It can be understood that the degradation determination unit 120 further comprises: a logarithmic transformation subunit configured to perform logarithmic transformation on the original energy spectrum to obtain a first energy spectrum; a straight line determination subunit configured to determine an approximate straight line of the first energy spectrum; an information acquisition subunit configured to acquire a straight line slope and a straight line intercept of the approximate straight line; and a first degradation determination subunit configured to determine a first degradation energy spectrum based on the straight line slope, the straight line intercept, and an input compensation value.

[0143] Understandably, the target determination unit 130 further includes: a fourth fading determination subunit, used to perform an exponential transformation on the first fading energy spectrum to obtain a fourth fading energy spectrum; a difference subunit, 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 fading energy spectrum to obtain a second energy spectrum; and a second target acquisition subunit, 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] Understandably, the straight line determines the sub-unit, specifically used for: obtaining the first address and the second address; obtaining the first photon count corresponding to the first address on the first energy spectrum, and the second photon count corresponding to the second address on the first energy spectrum; and obtaining an approximate straight line based on the first address, the first photon count, the second address, and the second photon count.

[0145] It should be understood that further implementation details of the oil-water contrast acquisition device 10 for full-spectrum logging data in this embodiment of the invention are as described in the aforementioned method for acquiring oil-water contrast of full-spectrum logging data, and will not be repeated here for the sake of brevity.

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

[0147] Among them, Figure 13 In this document, a bus architecture (represented by bus 1300) is used. Bus 1300 may include any number of interconnected buses and bridges, linking 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 peripheral devices, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described further 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, i.e., 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 during operation.

[0148] The embodiment of the present application determines the original energy spectrum of the full spectrum logging data; determines the first descending energy spectrum of the full spectrum logging data based on the original energy spectrum, the first descending energy spectrum is used to reduce the influence of the Compton scattering effect on the original energy spectrum; performs energy spectrum descending processing on the original energy spectrum based on the first descending 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 original energy spectrum is processed by the first descending energy spectrum, the accuracy of the photon count of each trace in the energy spectrum is improved, and therefore, the influence of the Compton scattering effect on the oil-water contrast precision of the full spectrum logging data is reduced.

[0149] The functions described herein can be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions can be stored on or transferred over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope and spirit of the disclosure and appended claims. For example, due to the nature of software, functions described above can be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions can also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations. Also, as technology evolves, the underlying functions and techniques can be implemented by equivalent hardware and / or software elements without departing from the scope and spirit of the disclosure.

[0150] In several embodiments provided in the present application, it should be understood that the disclosed technical content can be implemented by other ways. Among them, the above-mentioned device embodiments are only schematic, for example, the division of the units can be a logical function division, and actual implementation can have another division way, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point, the coupling or direct coupling or communication connection between the displayed or discussed each other can be through some interface, indirect coupling or communication connection between units or modules, which can be electrical or other forms.

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

[0152] The integrated unit, if implemented in the form of a software function unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application, essentially or in other words, the part that contributes to the prior art or the whole or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: a U disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a mobile hard disk, a magnetic disk or an optical disk, and various media that can store program codes.

[0153] The above only describes the embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the scope of the claims of the present application.

Claims

1. A method for obtaining oil-water contrast from full-spectrum logging data, characterized in that, The method comprises: determining an original energy spectrum of the full spectrum logging data; determining a first degrading energy spectrum of the full spectrum logging data based on the original energy spectrum, the first degrading energy spectrum being used to reduce the influence of Compton scattering effect on the original energy spectrum; the determining of the first degrading energy spectrum of the full spectrum logging data based on the original energy spectrum comprises: determining a second slope based on an input first slope and an amplification coefficient; determining 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 a second change acceleration of counts in the second energy window; determining a second degrading energy spectrum based on the second slope and the first change acceleration; determining a third degrading energy spectrum based on the first slope and the second change acceleration; comparing the photon counts of each channel address in the second degrading energy spectrum with the photon counts of the corresponding channel address in the third degrading energy spectrum, and obtaining the first degrading energy spectrum based on the larger photon counts; performing energy spectrum degrading processing on the original energy spectrum based on the first degrading energy spectrum to obtain a target energy spectrum of the full spectrum logging data; obtaining oil-water contrast of the full spectrum logging data based on the target energy spectrum.

2. The method for oil-water contrast acquisition from full-spectrum logging data according to claim 1, characterized in that, the performing of the energy spectrum degrading processing on the original energy spectrum based on the first degrading energy spectrum to obtain the target energy spectrum of the full spectrum logging data comprises: subtracting the photon counts of each channel address in the original energy spectrum from the photon counts of the corresponding channel address in the first degrading energy spectrum to obtain the target energy spectrum.

3. The method for oil-water contrast acquisition from full-spectrum logging data according to claim 1, characterized in that, the determining of the first energy window and the second energy window of the original energy spectrum comprises: obtaining a target energy window and a hydrogen peak of the original energy spectrum; dividing the target energy window into the first energy window and the second energy window based on the hydrogen peak.

4. The method for obtaining oil-water contrast of full spectrum logging data according to claim 1, wherein: the determining of the first change acceleration of counts in the first energy window comprises: obtaining a first coefficient, a first photon count of the first energy window, and a first number of channel addresses of the first energy window; determining the first change acceleration of counts in the first energy window based on the first coefficient, the first photon count, and the first number of channel addresses; the determining of the second change acceleration of counts in the second energy window comprises: obtaining a second coefficient, a second photon count of the second energy window, and a second number of channel addresses of the second energy window; determining the second change acceleration of counts in the second energy window based on the second coefficient, the second photon count, and the second number of channel addresses.

5. A method for obtaining oil-water contrast from full-spectrum logging data, characterized in that, The method comprises: determining an original energy spectrum of the full spectrum logging data; determining a first degrading energy spectrum of the full spectrum logging data based on the original energy spectrum, the first degrading energy spectrum being used to reduce the influence of Compton scattering effect on the original energy spectrum; The determining the first falling energy spectrum of the full spectrum logging data based on the original energy spectrum comprises: 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 a straight line slope and a straight line intercept of the approximate straight line; and determining the first falling energy spectrum based on the straight line slope, the straight line intercept and an input compensation value; The energy spectrum falling processing is performed on the original energy spectrum based on the first falling energy spectrum to obtain a target energy spectrum of the full spectrum logging data; The oil-water contrast of the full spectrum logging data is obtained based on the target energy spectrum.

6. The method of oil-water contrast acquisition from full-spectrum logging data according to claim 5, characterized in that, The energy spectrum falling processing performed on the original energy spectrum based on the first falling energy spectrum to obtain the target energy spectrum of the full spectrum logging data comprises: performing exponential transformation on the first falling energy spectrum to obtain a fourth falling energy spectrum; subtracting the photon count of each trace address of the original energy spectrum from the photon count of the corresponding trace address in the fourth falling energy spectrum to obtain a second energy spectrum; comparing the photon count of each trace address of the original energy spectrum with the photon count of the corresponding trace address in the second energy spectrum, and obtaining the target energy spectrum based on the smaller photon count.

7. The method of oil-water contrast acquisition from full-spectrum logging data according to claim 5, characterized in that, The determining the approximate straight line of the first energy spectrum comprises: obtaining a first trace address and a second trace address; obtaining a first photon count corresponding to the first trace address on the first energy spectrum and a second photon count corresponding to the second trace address on the first energy spectrum; obtaining the approximate straight line based on the first trace address, the first photon count, the second trace address and the second photon count.

8. An apparatus for obtaining oil-water contrast from full-spectrum logging data, the apparatus comprising: It comprises: an original determination unit configured to determine an original energy spectrum of full spectrum logging data; a falling determination unit configured to determine a first falling energy spectrum of the full spectrum logging data based on the original energy spectrum, the first falling energy spectrum being used to reduce the influence of Compton scattering effect on the original energy spectrum; The determining the first falling energy spectrum of the full spectrum logging data based on the original energy spectrum comprises: determining a second slope based on an input first slope and an amplification coefficient; determining a first energy window and a second energy window of the original energy spectrum; determining a first change acceleration of counting in the first energy window and a second change acceleration of counting in the second energy window; determining a second falling energy spectrum based on the second slope and the first change acceleration; determining a third falling energy spectrum based on the first slope and the second change acceleration; comparing the photon count of each trace address of the second falling energy spectrum with the photon count of the corresponding trace address in the third falling energy spectrum, and obtaining the first falling energy spectrum based on the larger photon count; a target determination unit configured to perform energy spectrum falling processing on the original energy spectrum based on the first falling energy spectrum to obtain a target energy spectrum of the full spectrum logging data; a contrast obtaining unit configured to obtain an oil-water contrast of the full spectrum logging data based on the target energy spectrum.

9. An apparatus for obtaining oil-water contrast from full-spectrum logging data, the apparatus comprising: It comprises: an original determination unit configured to determine an original energy spectrum of full spectrum logging data; The degradation determination unit is configured to determine a 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. The determination of the first degraded energy spectrum based on the original energy spectrum comprises: 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 a straight line slope and a straight line intercept of the approximate straight line; and determining the first degraded energy spectrum based on the straight line slope, the straight line intercept and an input compensation value. The target determination unit is configured to perform 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. The contrast acquisition unit is configured to acquire an oil-water contrast of the full spectrum logging data based on the target energy spectrum.

10. An electronic device, comprising: The computer program is stored in the memory and executable on the processor, and the processor executes the computer program to implement the method in any one of claims 1-4 or claims 5-7. The computer program is stored in the memory and executable on the processor, and the processor executes the computer program to implement the method in any one of claims 1-4 or claims 5-7.

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