Reservoir fluid identification method and device based on nuclear magnetic resonance T2 spectrum cutoff value backward shift

Abstract

The invention discloses a reservoir fluid identification method and device based on nuclear magnetic resonance T2 spectrum cutoff value backward movement, and relates to the technical field of petroleum logging, and the method comprises the steps: determining T2 spectrum characteristics of a movable fluid according to the obtained production data of a target oil field work area and nuclear magnetic resonance logging data, determining a corresponding T2cutoff critical value based on the peak value of the movable fluid in the T2 spectrum characteristic; determining the target value of the movable fluid based on the maximum T2 value of the spectrum peak in the T2 spectrum characteristic and the T2cutoff critical value; wherein the target value is used for representing the oiliness of the reservoir; analyzing the target values of the movable fluids to obtain a limit value of the target values among the movable fluids; and identifying a target value of the to-be-identified reservoir fluid based on the limit value, and determining the reservoir fluid property of the to-be-identified reservoir fluid according to an obtained identification result. Therefore, the fluid property in the reservoir can be judged according to the nuclear magnetic resonance T2 spectrum.

Description

Technical Field

[0001] The present invention relates to the technical field of petroleum well logging, in particular to a method based on nuclear magnetic resonance (NMR) 2 A reservoir fluid identification method and device with a spectrum cutoff value shifted backward. Background Art

[0002] Nuclear magnetic resonance logging technology detects information about pore structure and pore fluid by measuring the amplitude and relaxation rate of nuclear magnetic resonance relaxation signals of hydrogen nuclei in pore fluids of formation rocks. The amplitude of hydrogen nucleus relaxation signals is proportional to the porosity of the formation, and the transverse relaxation time T is proportional to the porosity of the formation. 2 Related to pore size and fluid properties.

[0003] Nuclear magnetic resonance logging is widely used because it can provide geological information related to reservoir properties and productivity, such as total porosity, effective porosity, permeability, free fluid and bound fluid volume, pore structure, etc. It has shown its unique advantages in low-porosity and low-permeability reservoirs, thin layer evaluation and complex reservoir fluid identification, and has become an indispensable and important logging method for solving various complex geological problems in oilfield exploration and development.

[0004] In current applications, NMR logging mainly uses differential spectrum, shift spectrum, two-dimensional NMR plate and other methods to identify reservoir fluid types. The former two require different measurement modes and parameters, and the latter requires software and hardware upgrades and support. Therefore, a conventional standard T 2 It is particularly important to process the spectrum, focus and highlight the oil signal, and suppress the water signal.

[0005] In summary, how to use NMR T 2 Spectral discrimination of fluid properties in reservoirs is a problem that needs to be solved urgently. Summary of the invention

[0006] In view of this, the object of the present invention is to provide a method based on nuclear magnetic resonance T 2 Reservoir fluid identification method and device with spectral cutoff value shifted backward can be used according to nuclear magnetic resonance T 2 The specific scheme is as follows:

[0007] In the first aspect, the present application provides a method based on nuclear magnetic resonance T 2 The reservoir fluid identification method with spectrum cutoff value shifted backward includes:

[0008] Determine the T of the movable fluid based on the production data of the target oil field area and the nuclear magnetic resonance logging data 2 Spectral characteristics, based on the T 2 The peak of the movable fluid in the spectral characteristics determines the corresponding T 2 cutoff critical value;

[0009] Based on the T 2 The maximum peak T in the spectrum feature 2 Values ​​and T 2 The cutoff critical value determines the target value of the movable fluid; wherein the target value is used to characterize the oil content of the reservoir;

[0010] analyzing the target values ​​of the movable fluids to obtain limit values ​​of the target values ​​between the movable fluids;

[0011] The target value of the reservoir fluid to be identified is identified based on the limit value, and the reservoir fluid property of the reservoir fluid to be identified is determined according to the obtained identification result.

[0012] Optionally, the T 2 The peak of the movable fluid in the spectral characteristics determines the corresponding T 2 Cutoff critical values ​​include:

[0013] Based on T 2 T corresponding to the oil layer peak in the spectrum characteristics 2 value and the corresponding first preset spectral peak focusing coefficient, and based on T 2 T corresponding to the water layer peak in the spectrum characteristics 2 The value and the corresponding second preset spectral peak focusing coefficient are used to determine the T of the oil layer and the water layer. 2 cutoff critical value.

[0014] Optionally, the T 2 The maximum peak T in the spectrum feature 2 Values ​​and T 2 The cutoff critical value determines the target value of the movable fluid, including:

[0015] The spectral envelope area integration method is based on the T 2 The maximum peak T in the spectrum feature 2 Values ​​and T 2 The cutoff threshold value determines the target value of the movable fluid.

[0016] Optionally, the T 2 The maximum peak T in the spectrum feature 2 Values ​​and T 2 The cutoff critical value determines the target value of the movable fluid, including:

[0017] Based on the T 2 The corresponding peak maximum T in the spectrum feature 2 Values ​​and T 2The cutoff critical values ​​determine the target values ​​of the oil layer, the water layer and the dry layer respectively.

[0018] Optionally, analyzing the target values ​​of the movable fluids to obtain limit values ​​of the target values ​​between the movable fluids includes:

[0019] Analyze the target values ​​corresponding to the oil layer, water layer and dry layer by plotting the intersection of total nuclear magnetic porosity and movable fluid porosity;

[0020] A first limit value of the target value between the oil layer and the water layer is determined, and a second limit value of the target value between the oil layer and the dry layer is determined.

[0021] Optionally, identifying the target value of the reservoir fluid to be identified based on the limit value, and determining the reservoir fluid property of the reservoir fluid to be identified according to the obtained identification result, includes:

[0022] The target value of the reservoir fluid to be identified is identified according to the determined first limit value and the second limit value, and the reservoir fluid property of the reservoir fluid to be identified is determined according to the obtained identification result.

[0023] In the second aspect, the present application provides a method based on nuclear magnetic resonance T 2 A reservoir fluid identification device with a spectrum cutoff value shifted backwards, comprising:

[0024] The critical value determination module is used to determine the T of the movable fluid based on the production data of the target oil field area and the nuclear magnetic resonance logging data. 2 Spectral characteristics, based on the T 2 The peak of the movable fluid in the spectral characteristics determines the corresponding T 2 cutoff critical value;

[0025] A target value determination module is used to determine the target value based on the T 2 The maximum peak T in the spectrum feature 2 Values ​​and T 2 The cutoff critical value determines the target value of the movable fluid; wherein the target value is used to characterize the oil content of the reservoir;

[0026] A limit value acquisition module, used for analyzing the target values ​​of the movable fluids to obtain limit values ​​of the target values ​​between the movable fluids;

[0027] The reservoir fluid property identification module is used to identify the target value of the reservoir fluid to be identified based on the limit value, and determine the reservoir fluid property of the reservoir fluid to be identified according to the obtained identification result.

[0028] In a third aspect, the present application provides an electronic device, including:

[0029] Memory, used to store computer programs;

[0030] A processor, configured to execute the computer program to implement the aforementioned method based on nuclear magnetic resonance T 2 Reservoir fluid identification method by shifting the spectrum cutoff value backward.

[0031] In a fourth aspect, the present application provides a computer-readable storage medium for storing a computer program; wherein, when the computer program is executed by a processor, the aforementioned method based on nuclear magnetic resonance T is implemented. 2 Reservoir fluid identification method by shifting the spectrum cutoff value backward.

[0032] In summary, the present application determines the T of the movable fluid by obtaining the production data of the target oil field area and the nuclear magnetic resonance logging data. 2 Spectral characteristics, based on the T 2 The peak of the movable fluid in the spectral characteristics determines the corresponding T 2 cutoff critical value; based on the T 2 The maximum peak T in the spectrum feature 2 Values ​​and T 2 The cutoff critical value determines the target value of the movable fluid; the target value of the movable fluid is analyzed to obtain the boundary value of the target value between each movable fluid; the target value of the reservoir fluid to be identified is identified based on the boundary value, and the reservoir fluid properties of the reservoir fluid to be identified are determined according to the obtained identification result. As can be seen from the above, the present application first obtains production data and nuclear magnetic resonance logging data, thereby determining the T of the movable fluid. 2 Spectral characteristics, according to T 2 The peak value of the movable fluid in the spectral characteristics determines T 2 Cutoff critical value, T 2 The maximum peak T of the movable fluid in the spectrum characteristics 2 Value and T 2 The cutoff critical value determines the target value, analyzes the target value to obtain the limit value, and finally identifies the reservoir fluid properties of the reservoir fluid to be identified based on the limit value. 2 The spectrum can focus and highlight the reservoir fluid signal to be identified, thereby providing reliable data for reservoir fluid identification, reservoir evaluation, target window optimization, completion plan preparation, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0034] Figure 1 The invention provides a method based on nuclear magnetic resonance T 2 Flow chart of the reservoir fluid identification method with spectral cutoff value shifted backward;

[0035] Figure 2 A schematic diagram of a nuclear magnetic spectrum of a reservoir with different fluid properties disclosed in the present invention;

[0036] Figure 3 A schematic diagram of a nuclear magnetic spectrum of reservoirs with different fluid properties in a certain block disclosed in the present invention;

[0037] Figure 4 It is a schematic diagram of the intersection of total nuclear magnetic porosity and movable fluid porosity disclosed in the present invention;

[0038] Figure 5 A schematic diagram of a nuclear magnetic spectrum of a reservoir fluid to be identified disclosed in the present invention;

[0039] Figure 6 The invention discloses a method based on nuclear magnetic resonance T 2 Schematic diagram of the structure of a reservoir fluid identification device with a spectrum cutoff value shifted backward;

[0040] Figure 7 The present invention is a structural diagram of an electronic device disclosed in the present invention. DETAILED DESCRIPTION

[0041] 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.

[0042] At present, NMR logging mainly uses differential spectrum, shift spectrum, two-dimensional NMR plate and other methods to identify reservoir fluid types. The former two require different measurement modes and parameters, and the latter requires software and hardware upgrades and support. Therefore, a conventional standard T 2 In order to solve the above technical problems, the present application discloses a method based on nuclear magnetic resonance T 2A reservoir fluid identification method and device with a spectrum cutoff value shifted backward can be used according to the nuclear magnetic resonance logging standard T 2 Spectrum to identify fluid properties in reservoirs.

[0043] See also Figure 1 As shown, the embodiment of the present invention discloses a method based on nuclear magnetic resonance T 2 The reservoir fluid identification method with spectrum cutoff value shifted backward includes:

[0044] Step S11: Determine the T of the movable fluid based on the production data of the target oil field area and the nuclear magnetic resonance logging data. 2 Spectral characteristics, based on the T 2 The peak of the movable fluid in the spectral characteristics determines the corresponding T 2 cutoff critical value.

[0045] In this embodiment, firstly, comprehensive and detailed data collection is carried out on the target oilfield work area to obtain detailed production data of the target oilfield work area, such as key information such as oil well production, pressure changes, water content, etc., and at the same time, advanced nuclear magnetic resonance logging technology is used to obtain accurate logging data.

[0046] Next, the production data and NMR logging data of the target oilfield area are analyzed to determine Figure 2 The movable fluid T 2 Spectral characteristics. The movable fluid includes oil layer, water layer and dry layer. 2 As an important parameter in NMR logging data, the spectrum can intuitively reflect the relaxation characteristics of fluids in different pore sizes, and thus reflect the distribution law and content information of movable fluids. 2 The spectra are mostly bimodal, with the main peak at the back and the amplitude slow; the T 2 The spectrum is unimodal or bimodal, with the main peak in the middle position and the largest amplitude; the T 2 It is mostly unimodal or bimodal distribution, with the main peak located at the front and the amplitude increasing the closer it is to the front.

[0047] Typically, It is the boundary between bound fluid and movable fluid, distinguishing the fast relaxing component reflecting the water in small pores and micropores from the slow relaxing component reflecting the water in movable pores. 2 The peak value of the movable fluid is determined by the spectrum characteristics, and the T2cutoff critical value is set to a value in the direction of the preset cutoff value based on the peak value of the movable fluid. Since the value cannot be set too far in the direction of the preset cutoff value, an empirical formula is summarized based on multiple factors such as rock physical properties, fluid properties, and actual production dynamics, namely, 2 T corresponding to the oil layer peak in the spectrum characteristics2 value and the corresponding first preset spectral peak focusing coefficient, and based on T 2 T corresponding to the water layer peak in the spectrum characteristics 2 The corresponding second preset spectrum peak focusing coefficient is used to calculate the corresponding oil layer signal and water layer signal. Critical value:

[0048] ;

[0049] in, It is the boundary value between water signal and oil signal, in milliseconds; T is the oil layer peak value corresponding to 2 Numeric value, in milliseconds; T is the peak value of the water layer 2 The value is in milliseconds; is the first preset spectral peak focusing factor, which is determined based on a large number of rock physics experimental studies; is the second preset spectral peak focusing coefficient, which is determined based on a large number of rock physics experimental studies; in fracture-cavity formations, Take 4, Take 3, in the matrix pore type formation, Take 2, Take 5.

[0050] In a specific implementation, the target oilfield area is set as a mudstone fracture-cavity reservoir, which has the characteristics of complex lithology, high mud content, well-developed fractures and caves, and complex oil-water relationship. Figure 3 T 2 Spectral characteristics, T of oil layer 2 The spectrum is mostly bimodal, with the first peak around 1ms and the second peak around 100ms, with a slow amplitude. 2 The spectrum is unimodal or bimodal, with the first peak near 1ms and the second peak near 30ms, with the largest amplitude; the T of the dry layer (low water production layer) 2 It is usually single-peak or double-peaked, with the first peak around 1ms and the second peak around 30ms. Relative to the oil layer, the first wave has a large amplitude and the second wave has a small amplitude. 2 The spectrum still has amplitude after 300ms, and the water layer standard T 2 The spectrum has almost no amplitude after 300ms. Figure 3 In is 100ms, is 30ms, combined with formula 1, it can be obtained that the It is 310ms.

[0051] Step S12: Based on the T 2 The maximum peak T in the spectrum feature 2Values ​​and The critical value determines the target value of the movable fluid; wherein the target value is used to characterize the oil content of the reservoir.

[0052] In this embodiment, the T obtained by nuclear magnetic resonance logging 2 Analysis of spectral features to obtain T 2 The maximum peak T of the spectral feature 2 Numerical and confirmed Critical value, using the spectral envelope area integration method to calculate the target value of the movable fluid:

[0053] ;

[0054] in, is the pseudo movable fluid porosity, unit is %; T 2 max is the maximum peak T 2 Numeric value, in milliseconds; is the boundary value between water signal and oil signal, in milliseconds. In T 2 The spectrum characteristics shift to the right, and the MBVM (Microbial Biological Volume Measurement, movable fluid porosity) of the oil layer, water layer, and dry layer all decreases with different degrees of decrease. At this time, MBVM no longer represents the size of the movable fluid in the formation, but can be used to determine the properties of the fluid. Therefore, it is called "pseudo movable fluid porosity", that is, the target value.

[0055] In a specific implementation, a tested well in the target oilfield is selected to establish a standard, for example, the YS101 well has 1 oil layer, 1 water layer, and 1 dry layer, with a total of 20 points to calculate the oil layer, water layer, and dry layer. , see Table 1.

[0056] Table 1

[0057]

[0058] It can be understood that for different formation types, such as oil layer, water layer and dry layer, each has its own corresponding T 2 The maximum peak T in the spectrum feature 2 Numerical and Critical value, carry out targeted spectrum envelope area integration operation. In the oil layer, by accurately defining T 2 The maximum peak T of the spectral feature 2 Numerical and specific Critical value, using the spectrum envelope area integral to accurately calculate the value that can accurately reflect the oil layer In the water layer, the maximum T2 The values ​​and corresponding Critical value, determined by the spectral envelope area integration method for the water layer For the dry layer, by based on T 2 The maximum peak T in the spectrum feature 2 The values ​​and corresponding The critical value is used to integrate the spectral envelope area to obtain the dry layer .

[0059] Step S13, analyzing the target values ​​of the movable fluids to obtain limit values ​​of the target values ​​between the movable fluids.

[0060] In this embodiment, after obtaining the oil layer, water layer, and dry layer After obtaining the values, it is necessary to obtain the target values ​​corresponding to the oil layer, water layer and dry layer by plotting the intersection of total nuclear magnetic porosity and movable fluid porosity; determine the first limit value of the target value between the oil layer and the water layer, and determine the second limit value of the target value between the oil layer and the dry layer. Then, the corresponding porosity of each layer was analyzed by using the NMR total porosity and movable fluid porosity intersection method. For each stratum, the distribution of data points in the intersection diagram is used to obtain the First, determine the distance between the oil layer and the water layer. When the first limit value is obtained, the distribution of the two in the intersection diagram and the difference in target values ​​are observed. From the lower limit of the oil layer target value and the upper limit of the water layer target value, the limit value is determined by analyzing the change law of data points near the boundary and using linear fitting and other methods. Similarly, the difference between the oil layer and the dry layer is determined. The second limit value of the target value of the dry layer is low and has a special distribution. The transition zone between the target value of the dry layer and the target value of the oil layer is found. The second limit value of the target value between the oil layer and the dry layer is determined by similar analysis. For example, Figure 4 The cross-plot of total NMR porosity and movable fluid porosity shown is obtained by analyzing the target value of the movable fluid to obtain the boundary value of the target value between each movable fluid. The boundary of the movable fluid porosity between the oil layer and the water layer is very clearly indicated as 1.4%, that is, after focusing, when it is greater than 1.4%, it is an oil layer, and when it is less than or equal to 1.4%, it is a water (dry) layer.

[0061] Step S14: identifying the target value of the reservoir fluid to be identified based on the limit value, and determining the reservoir fluid properties of the reservoir fluid to be identified according to the obtained identification result.

[0062] In this embodiment, a critical threshold value is determined through a large amount of experimental data, geological analysis and complex numerical calculations. First, the T of the reservoir fluid to be identified is obtained. 2 Spectral data, through the T 2 After obtaining the target value of the reservoir fluid to be identified by analyzing the spectrum data, it is carefully compared with the established boundary values. The target value of the reservoir fluid to be identified is identified according to the determined first boundary value and the second boundary value, and the reservoir fluid properties of the reservoir fluid to be identified are determined according to the obtained identification results. , first compare it with the first threshold value. A value higher than the first limit indicates that the reservoir fluid has certain characteristics of an oil layer.

[0063] On the contrary, if the target value is lower than the first limit value, it is necessary to further judge its relationship with the second limit value. If the target value is lower than the second limit value, then the reservoir fluid is most likely of dry layer nature. Since the pore space of the dry layer is filled with a large amount of solid minerals and the movable fluid content is very small, this causes the target value reflecting the reservoir characteristics to be at a low level, far below the limit value range that can form an effective oil layer or water layer. When the target value is between the first limit value and the second limit value, the situation is relatively complicated. This may mean that the reservoir fluid has the characteristics of oil and water mixing, or is affected by some special geological conditions, such as abnormal local formation pressure, strong rock heterogeneity, etc., which makes its target value in this transition interval.

[0064] In a specific implementation, fluid identification is performed on three reservoirs to be determined in a block, and the following is first obtained: Figure 5 T 2 spectral data, and then determine the reservoir fluids shown in Table 2 The calculation results are obtained by The calculated results are compared with the first limit value and the second limit value, and the fluids in the three reservoirs are determined to be oil layers.

[0065] Table 2

[0066]

[0067] As can be seen from the above, the embodiment of the present application first obtains production data and nuclear magnetic resonance logging data, thereby determining the T of the movable fluid. 2 Spectral characteristics, according to T 2 Peak determination of movable fluid in spectral characteristics Critical value, T 2 The maximum peak T of the movable fluid in the spectrum characteristics2 Numerical and The critical value determines the target value, the target value is analyzed to obtain the limit value, and finally the reservoir fluid properties of the reservoir fluid to be identified are identified according to the limit value. 2 spectrum, so that the reservoir fluid signal to be identified can be focused and highlighted, thus providing a basis for the nuclear magnetic resonance T 2 The spectrum cutoff value shifted backward provides reliable data for reservoir fluid identification, reservoir evaluation, target window optimization, and completion plan preparation.

[0068] Based on the above embodiment, it can be seen that the present application discloses a method based on nuclear magnetic resonance T 2 The reservoir fluid identification method based on the spectral cutoff value shifting back can be used to identify the reservoir fluid according to the nuclear magnetic resonance T 2 Next, we will focus on the specific NMR-based T 2 The reservoir fluid identification method with the spectrum cutoff value shifted backward is described in detail.

[0069] The present invention firstly collects data of the target oilfield area in a comprehensive and detailed manner, obtains detailed production data and accurate logging data of the target oilfield area, analyzes the production data and nuclear magnetic resonance logging data of the target oilfield area, and determines the T of the movable fluid in the target oilfield area. 2 Then, according to the T of the movable fluid 2 Spectral feature calculation of oil layer signal and water layer signal Next, obtain T 2 The maximum peak T of the spectral feature 2 Numerical and confirmed Critical values ​​are used to determine the oil layer, water layer, and dry layer in the target oil field area using the spectrum envelope area integration method. . After obtaining the oil layer, water layer, and dry layer After the numerical value is obtained, the corresponding porosity of each layer is analyzed by using the intersection method of total NMR porosity and movable fluid porosity. , determine the distance between the oil layer and the water layer The first limit value of the oil layer and the dry layer Finally, the obtained reservoir fluid to be identified , the reservoir fluid to be identified The determined first limit value and the second limit value are compared, and the reservoir fluid properties of the reservoir fluid to be identified are determined according to the comparison results. 2 The spectrum is processed to focus and highlight the oil signal and suppress the water signal, which can accurately identify the oil layer and greatly expand and enrich the standard T of nuclear magnetic resonance logging. 2 Application of spectrum.

[0070] See also Figure 6 As shown, the embodiment of the present invention discloses a method based on nuclear magnetic resonance T 2 A reservoir fluid identification device with a spectrum cutoff value shifted backwards, comprising:

[0071] The critical value determination module 11 is used to determine the T of the movable fluid based on the production data of the target oil field area and the nuclear magnetic resonance logging data. 2 Spectral characteristics, based on the T 2 The peak of the movable fluid in the spectral characteristics determines the corresponding T 2 cutoff critical value;

[0072] The target value determination module 12 is used to determine the target value based on the T 2 The maximum peak T in the spectrum feature 2 Values ​​and T 2 The cutoff critical value determines the target value of the movable fluid; wherein the target value is used to characterize the oil content of the reservoir;

[0073] A limit value acquisition module 13, used for analyzing the target values ​​of the movable fluids to obtain limit values ​​of the target values ​​between the movable fluids;

[0074] The reservoir fluid property identification module 14 is used to identify the target value of the reservoir fluid to be identified based on the limit value, and determine the reservoir fluid property of the reservoir fluid to be identified according to the obtained identification result.

[0075] As can be seen from the above, the present application first obtains production data and nuclear magnetic resonance logging data, thereby determining the T of the movable fluid. 2 Spectral characteristics, according to T 2 The peak value of the movable fluid in the spectral characteristics determines T 2 Cutoff critical value, T 2 The maximum peak T of the movable fluid in the spectrum characteristics 2 Value and T 2 The cutoff critical value determines the target value, analyzes the target value to obtain the limit value, and finally identifies the reservoir fluid properties of the reservoir fluid to be identified based on the limit value. 2 The spectrum can focus and highlight the signals of reservoir fluids to be identified, thereby providing reliable data for reservoir fluid identification, reservoir evaluation, target window optimization, and completion plan preparation based on the backward shift of the cutoff value of the nuclear magnetic resonance T2 spectrum.

[0076] In a specific embodiment, the movable fluid includes an oil layer, a water layer and a dry layer.

[0077] In a specific embodiment, the critical value determination module 11 may specifically include:

[0078] The critical value determination unit of oil layer and water layer is used to determine the critical value of oil layer and water layer based on T 2 T corresponding to the oil layer peak in the spectrum characteristics 2 value and the corresponding first preset spectral peak focusing coefficient, and based on T 2 T corresponding to the water layer peak in the spectrum characteristics 2 The value and the corresponding second preset spectral peak focusing coefficient are used to determine the T of the oil layer and the water layer. 2 cutoff critical value.

[0079] In a specific embodiment, the target value determination module 12 may specifically include:

[0080] The first target value determination unit is used to use the spectrum envelope area integration method based on the T 2 The maximum peak T in the spectrum feature 2 Values ​​and T 2 The cutoff threshold value determines the target value of the movable fluid.

[0081] In a specific embodiment, the target value determination module 12 may specifically include:

[0082] The second target value determination unit is used to determine the target value based on the T 2 The corresponding peak maximum T in the spectrum feature 2 Values ​​and T 2 The cutoff critical values ​​determine the target values ​​of the oil layer, the water layer and the dry layer respectively.

[0083] In a specific embodiment, the limit value acquisition module 13 may specifically include:

[0084] A first limit value and a second limit value determination unit, used for analyzing the target values ​​corresponding to the oil layer, the water layer and the dry layer by plotting the intersection of the total nuclear magnetic porosity and the movable fluid porosity;

[0085] The unit is used to determine a first limit value of the target value between the oil layer and the water layer, and to determine a second limit value of the target value between the oil layer and the dry layer.

[0086] In a specific embodiment, the reservoir fluid property identification module 14 may specifically include:

[0087] The reservoir fluid property identification unit is used to identify the target value of the reservoir fluid to be identified based on the determined first limit value and the second limit value, and determine the reservoir fluid property of the reservoir fluid to be identified based on the obtained identification result.

[0088] Furthermore, the present application also discloses an electronic device. Figure 7 This is a structural diagram of an electronic device 20 according to an exemplary embodiment. The content in the diagram cannot be regarded as any limitation on the scope of use of the present application.

[0089] Figure 7 The structure diagram of an electronic device 20 provided in an embodiment of the present application. The electronic device 20 may include: at least one processor 21, at least one memory 22, a power supply 23, a communication interface 24, an input / output interface 25, and a communication bus 26. The memory 22 is used to store a computer program, which is loaded and executed by the processor 21 to implement the method based on nuclear magnetic resonance T 2 Related steps in the reservoir fluid identification method with spectrum cutoff value shifted backward. In addition, the electronic device 20 in this embodiment can be specifically an electronic computer.

[0090] In this embodiment, the power supply 23 is used to provide working voltage for each hardware device on the electronic device 20; the communication interface 24 can create a data transmission channel between the electronic device 20 and the external device, and the communication protocol it follows is any communication protocol that can be applied to the technical solution of the present application, and is not specifically limited here; the input and output interface 25 is used to obtain external input data or output data to the outside world, and its specific interface type can be selected according to specific application needs and is not specifically limited here.

[0091] In addition, the memory 22, as a carrier for storing resources, can be a read-only memory, a random access memory, a disk or an optical disk, etc. The resources stored thereon can include an operating system 221, a computer program 222, etc., and the storage method can be temporary storage or permanent storage.

[0092] The operating system 221 is used to manage and control the hardware devices on the electronic device 20 and the computer program 222, which can be Windows Server, Netware, Unix, Linux, etc. The computer program 222 includes the following: 2 In addition to the computer program of the reservoir fluid identification method with a spectrum cutoff value shifted backward, the invention may further include a computer program that can be used to complete other specific tasks.

[0093] Furthermore, the present application also discloses a computer-readable storage medium for storing a computer program; wherein, when the computer program is executed by a processor, the aforementioned disclosed method based on nuclear magnetic resonance T 2Reservoir fluid identification method with spectrum cutoff value shifted backward. The specific steps of this method can be referred to the corresponding contents disclosed in the above embodiments, and will not be described in detail here.

[0094] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0095] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0096] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0097] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0098] The technical solution provided by the present application is introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for general technicians in this field, according to the idea of ​​the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A reservoir fluid identification method based on the backward shift of the cutoff value of nuclear magnetic resonance T2 spectrum, characterized in that: include: Determine the T2 spectrum characteristics of the movable fluid based on the production data of the target oilfield work area and the nuclear magnetic resonance logging data, and determine the corresponding T2cutoff critical value based on the peak value of the movable fluid in the T2 spectrum characteristics; Determining a target value of the movable fluid based on the maximum T2 value of the spectrum peak in the T2 spectrum feature and the T2cutoff critical value; wherein the target value is used to characterize the oil content of the reservoir; analyzing the target values ​​of the movable fluids to obtain limit values ​​of the target values ​​between the movable fluids; The target value of the reservoir fluid to be identified is identified based on the limit value, and the reservoir fluid property of the reservoir fluid to be identified is determined according to the obtained identification result.

2. The reservoir fluid identification method based on the backward shift of the cutoff value of the nuclear magnetic resonance T2 spectrum according to claim 1 is characterized in that: The movable fluid includes an oil layer, a water layer and a dry layer.

3. The reservoir fluid identification method based on the backward shift of the cutoff value of the nuclear magnetic resonance T2 spectrum according to claim 2 is characterized in that: The determining of the corresponding T2cutoff critical value based on the peak value of the movable fluid in the T2 spectrum feature includes: Based on the T2 value corresponding to the oil layer peak in the T2 spectrum feature and the corresponding first preset spectrum peak focusing coefficient, and based on the T2 value corresponding to the water layer peak in the T2 spectrum feature and the corresponding second preset spectrum peak focusing coefficient, the T2cutoff critical values ​​of the oil layer and the water layer are determined.

4. The reservoir fluid identification method based on the backward shift of the cutoff value of the nuclear magnetic resonance T2 spectrum according to claim 1 is characterized in that: The step of determining the target value of the movable fluid based on the maximum T2 value of the spectrum peak in the T2 spectrum feature and the T2cutoff critical value includes: The target value of the movable fluid is determined based on the maximum T2 value of the spectrum peak in the T2 spectrum feature and the T2cutoff critical value by using a spectrum envelope area integration method.

5. The reservoir fluid identification method based on the backward shift of the cutoff value of the nuclear magnetic resonance T2 spectrum according to any one of claims 1 to 4, characterized in that: The step of determining the target value of the movable fluid based on the maximum T2 value of the spectrum peak in the T2 spectrum feature and the T2cutoff critical value includes: The target values ​​of the oil layer, the water layer and the dry layer are determined respectively based on the maximum T2 value of the spectral peak corresponding to the T2 spectral feature and the T2cutoff critical value.

6. The reservoir fluid identification method based on the backward shift of the cutoff value of the nuclear magnetic resonance T2 spectrum according to claim 5 is characterized in that: The analyzing the target values ​​of the movable fluids to obtain limit values ​​of the target values ​​between the movable fluids includes: Analyze the target values ​​corresponding to the oil layer, water layer and dry layer by plotting the intersection of total nuclear magnetic porosity and movable fluid porosity; A first limit value of the target value between the oil layer and the water layer is determined, and a second limit value of the target value between the oil layer and the dry layer is determined.

7. The reservoir fluid identification method based on the backward shift of the cutoff value of the nuclear magnetic resonance T2 spectrum according to claim 6 is characterized in that: The step of identifying the target value of the reservoir fluid to be identified based on the limit value, and determining the reservoir fluid property of the reservoir fluid to be identified according to the obtained identification result, comprises: The target value of the reservoir fluid to be identified is identified according to the determined first limit value and the second limit value, and the reservoir fluid property of the reservoir fluid to be identified is determined according to the obtained identification result.

8. A reservoir fluid identification device based on the backward shift of the cutoff value of nuclear magnetic resonance T2 spectrum, characterized in that: include: A critical value determination module is used to determine the T2 spectrum characteristics of the movable fluid based on the production data of the target oil field work area and the nuclear magnetic resonance logging data, and determine the corresponding T2cutoff critical value based on the peak value of the movable fluid in the T2 spectrum characteristics; A target value determination module, used to determine the target value of the movable fluid based on the maximum T2 value of the spectrum peak in the T2 spectrum feature and the T2cutoff critical value; wherein the target value is used to characterize the oil content of the reservoir; A limit value acquisition module, used for analyzing the target values ​​of the movable fluids to obtain limit values ​​of the target values ​​between the movable fluids; The reservoir fluid property identification module is used to identify the target value of the reservoir fluid to be identified based on the limit value, and determine the reservoir fluid property of the reservoir fluid to be identified according to the obtained identification result.

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