Method and device for determining rock pore fluid saturation based on multi-nuclear magnetic resonance

Abstract

The present invention discloses a method and apparatus for determining rock pore fluid saturation based on multi-nuclear magnetic resonance (MNMR), relating to the field of oil and gas exploration technology. By conducting a first NMR experiment using a first element and a second NMR experiment using a second element, the water-saturated / oil-saturated volume and total pore volume of a rock sample are determined. Determining the saturation of rock pore fluid using MMR effectively avoids the inaccurate calculation of oil-water saturation due to overlapping oil and water signals in a magnetic resonance relaxation spectrum, thereby improving the accuracy of oil-water saturation calculations.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas exploration, and in particular to a method and device for determining rock pore fluid saturation based on multi-nuclear magnetic resonance. Background Art

[0002] Reservoir oil and gas saturation directly determines the resource volume and potential economic value of a reservoir, and is crucial data in commercial feasibility analysis of oil and gas fields. Currently, magnetic resonance logging is an important geophysical logging method used to assess formation pore fluid saturation. However, with the continued advancement of exploration and development, conventional reservoir resources are decreasing, making the exploration, development, and utilization of unconventional reservoir oil and gas resources particularly important.

[0003] Unconventional reservoirs have low porosity and well-developed micro- and nano-pores. The nuclear magnetic resonance responses of different types of pore fluids are slightly different, resulting in serious overlap of different fluid signals in the magnetic resonance relaxation spectrum, which reduces the accuracy of rock pore fluid identification and saturation.

[0004] Therefore, how to improve the accuracy of rock pore fluid identification and saturation is an urgent problem that needs to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of the present invention is to provide a method and device for determining rock pore fluid saturation based on multi-nuclear magnetic resonance, so as to solve the problem that the different fluid signals in the current magnetic resonance relaxation spectrum are severely overlapped, resulting in reduced accuracy of rock pore fluid identification and saturation.

[0006] To solve the above technical problems, the present invention provides a method for determining rock pore fluid saturation based on multi-nuclear magnetic resonance, comprising:

[0007] Obtain target solution corresponding to formation water / oil sample of the formation where the rock is located and rock sample saturated with oil and water;

[0008] Performing a first nuclear magnetic resonance experiment and a second nuclear magnetic resonance experiment on the target solution, respectively, to determine the first element magnetic resonance signal intensity and the second element magnetic resonance signal intensity corresponding to the target solution; performing a first nuclear magnetic resonance experiment and a second nuclear magnetic resonance experiment on the rock sample, respectively, to determine the first element magnetic resonance signal intensity and the second element magnetic resonance signal intensity corresponding to the rock sample;

[0009] Determining the saturated water / saturated oil volume of the rock sample based on the first element magnetic resonance signal intensity of the target solution and the first element magnetic resonance signal intensity of the rock sample; and determining the pore volume of the rock sample based on the second element magnetic resonance signal intensity of the target solution and the second element magnetic resonance signal intensity of the rock sample;

[0010] The saturation of the rock is determined based on the water-saturated / oil-saturated volume of the rock sample and the pore volume of the rock sample.

[0011] On the one hand, performing a first nuclear magnetic resonance experiment and a second nuclear magnetic resonance experiment on the target solution respectively to determine the first element magnetic resonance signal intensity and the second element magnetic resonance signal intensity corresponding to the target solution, comprising:

[0012] Performing a first nuclear magnetic resonance experiment on a unit volume of the target solution to determine a first free induction decay signal of a first element;

[0013] determining a magnetic resonance signal intensity of a first element in the target solution according to a first free induction decay signal of the first element;

[0014] performing a second nuclear magnetic resonance experiment on a unit volume of the target solution to determine a first free induction decay signal of a second element;

[0015] The magnetic resonance signal intensity of the second element in the target solution is determined according to the first free induction decay signal of the second element.

[0016] On the other hand, performing a first nuclear magnetic resonance experiment and a second nuclear magnetic resonance experiment on the rock sample respectively to determine the intensity of the first element magnetic resonance signal and the intensity of the second element magnetic resonance signal corresponding to the rock sample, including:

[0017] Performing a first nuclear magnetic resonance experiment on each of the rock samples to determine a second free induction decay signal of the first element;

[0018] Inverting the second free induction decay signal of the first element to obtain a relaxation spectrum of the first element;

[0019] performing summing processing based on the amplitude of the relaxation spectrum of the first element to obtain the magnetic resonance signal intensity of the first element in the rock sample;

[0020] performing a second nuclear magnetic resonance experiment on each of the rock samples to determine a second free induction decay signal of a second element;

[0021] Inverting the second free induction decay signal of the second element to obtain a relaxation spectrum of the second element;

[0022] The magnetic resonance signal intensity of the second element in the rock sample is obtained by summing up the amplitude of the relaxation spectrum of the second element.

[0023] On the other hand, determining the saturated water / saturated oil volume of the rock sample according to the first element magnetic resonance signal intensity of the target solution and the first element magnetic resonance signal intensity of the rock sample comprises:

[0024] The first element magnetic resonance signal intensity of the rock sample is divided by the first element magnetic resonance signal intensity of the target solution to determine the saturated water / saturated oil volume of the rock sample.

[0025] In another aspect, determining the pore volume of the rock sample according to the second element magnetic resonance signal intensity of the target solution and the second element magnetic resonance signal intensity of the rock sample comprises:

[0026] The pore volume of the rock sample is determined by dividing the second element magnetic resonance signal intensity of the rock sample by the second element magnetic resonance signal intensity of the target solution.

[0027] On the other hand, in the case where the first element is 23 When the Na element is present, the saturation of the rock is determined according to the saturated water volume of the rock sample and the pore volume of the rock sample, including:

[0028] Determine the water saturation of the rock sample by dividing the saturated water volume of the rock sample by the pore volume of the rock sample;

[0029] The oil saturation of the rock sample is determined by subtracting 1 from the water saturation of the rock sample.

[0030] On the other hand, in the case where the first element is 13 When the C element is present, the saturation of the rock is determined according to the saturated oil volume of the rock sample and the pore volume of the rock sample, including:

[0031] Determine the oil saturation of the rock sample by dividing the saturated oil volume of the rock sample by the pore volume of the rock sample;

[0032] The water saturation of the rock sample is determined by subtracting 1 from the oil saturation of the rock sample.

[0033] To solve the above technical problems, the present invention further provides a device for determining rock pore fluid saturation based on multi-nuclear magnetic resonance, comprising:

[0034] An acquisition module is used to obtain a target solution corresponding to a formation water / oil sample of the formation where the rock is located and a rock sample saturated with oil and water;

[0035] A first determination module is configured to perform a first nuclear magnetic resonance experiment and a second nuclear magnetic resonance experiment on the target solution, respectively, to determine the intensity of the first element magnetic resonance signal and the second element magnetic resonance signal corresponding to the target solution; and perform a first nuclear magnetic resonance experiment and a second nuclear magnetic resonance experiment on the rock sample, respectively, to determine the intensity of the first element magnetic resonance signal and the second element magnetic resonance signal corresponding to the rock sample;

[0036] a second determination module, configured to determine the water-saturated / oil-saturated volume of the rock sample based on the first element magnetic resonance signal intensity of the target solution and the first element magnetic resonance signal intensity of the rock sample; and to determine the pore volume of the rock sample based on the second element magnetic resonance signal intensity of the target solution and the second element magnetic resonance signal intensity of the rock sample;

[0037] The third determination module is used to determine the saturation of the rock according to the saturated water / saturated oil volume of the rock sample and the pore volume of the rock sample.

[0038] To solve the above technical problems, the present invention further provides a multi-core-based rock pore fluid saturation determination device, comprising:

[0039] Memory for storing computer programs;

[0040] A processor is used to implement the steps of the method for determining rock pore fluid saturation based on multi-nuclear magnetic resonance when executing the computer program.

[0041] In order to solve the above technical problems, the present invention also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method for determining rock pore fluid saturation based on multi-nuclear magnetic resonance are implemented.

[0042] The present invention provides a method for determining rock pore fluid saturation based on multi-nuclear magnetic resonance, comprising: obtaining a target solution corresponding to a formation water / oil sample of a formation in which the rock is located and a rock sample saturated with oil and water; performing a first nuclear magnetic resonance experiment and a second nuclear magnetic resonance experiment on the target solution, respectively, to determine a first element magnetic resonance signal intensity and a second element magnetic resonance signal intensity corresponding to the target solution; performing a first nuclear magnetic resonance experiment and a second nuclear magnetic resonance experiment on the rock sample, respectively, to determine a first element magnetic resonance signal intensity and a second element magnetic resonance signal intensity corresponding to the rock sample; determining a water-saturated / oil-saturated volume of the rock sample based on the first element magnetic resonance signal intensity of the target solution and the first element magnetic resonance signal intensity of the rock sample; and determining a pore volume of the rock sample based on the second element magnetic resonance signal intensity of the target solution and the second element magnetic resonance signal intensity of the rock sample; and determining the saturation of the rock based on the water-saturated / oil-saturated volume of the rock sample and the pore volume of the rock sample. The present invention determines the saturated water / saturated oil volume and the total pore volume of a rock sample by performing a first nuclear magnetic resonance experiment using a first element and a second nuclear magnetic resonance experiment using a second element, and determines the saturation of the rock pore fluid through multi-nuclear magnetic resonance experiments, thereby effectively avoiding the problem of inaccurate oil-water saturation calculation due to overlapping oil and water signals in a magnetic resonance relaxation spectrum, and correspondingly improving the accuracy of oil-water saturation calculation.

[0043] In addition, the present invention also provides a device, equipment and medium for determining rock pore fluid saturation based on multi-nuclear magnetic resonance, which has the same beneficial effects as the above-mentioned method for determining rock pore fluid saturation based on multi-nuclear magnetic resonance. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present invention, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0045] Figure 1 A flowchart of a method for determining rock pore fluid saturation based on multi-nuclear magnetic resonance provided by an embodiment of the present invention;

[0046] Figure 2 A structural diagram of a device for determining rock pore fluid saturation based on multi-nuclear magnetic resonance provided by an embodiment of the present invention;

[0047] Figure 3 A structural diagram of a device for determining rock pore fluid saturation based on multi-nuclear magnetic resonance provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0048] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0049] The core of the present invention is to provide a method and device for determining rock pore fluid saturation based on multi-nuclear magnetic resonance to solve the problem that different fluid signals in the current magnetic resonance relaxation spectrum seriously overlap, resulting in reduced accuracy of rock pore fluid identification and saturation.

[0050] In order to enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0051] Generally speaking, rock magnetic resonance measurement technology refers to 1 H nuclear magnetic resonance technology. Currently, 1 H two-dimensional magnetic resonance technology can simultaneously collect two types of relaxation information of rock pore fluid, which is more convenient than one-dimensional magnetic resonance in fluid identification and saturation evaluation. 1 H magnetic resonance technology has obvious advantages. However, for unconventional reservoirs, the relaxation characteristics of pore fluids are similar, and the signals in the two-dimensional magnetic resonance relaxation spectrum overlap seriously. Although blind source separation methods are used to divide the fluid signal region and calculate the fluid saturation, the premise for the application of these methods is that the pore fluid relaxation time is different. Under different relaxation effects, different fluids in the pore may show the same relaxation time. At this time, the blind source separation method divides the fluid signal region, resulting in inaccurate saturation calculation. The method for determining rock pore fluid saturation based on multi-nuclear magnetic resonance provided by the present invention can solve the above technical problems.

[0052] Figure 1 A flow chart of a method for determining rock pore fluid saturation based on multi-nuclear magnetic resonance is provided in an embodiment of the present invention, such as Figure 1 As shown, this includes:

[0053] S11: Obtaining a target solution corresponding to a formation water / oil sample of the formation where the rock is located and a rock sample saturated with oil and water;

[0054] S12: performing a first nuclear magnetic resonance experiment and a second nuclear magnetic resonance experiment on the target solution, respectively, to determine the intensity of the first element magnetic resonance signal and the second element magnetic resonance signal corresponding to the target solution; performing a first nuclear magnetic resonance experiment and a second nuclear magnetic resonance experiment on the rock sample, respectively, to determine the intensity of the first element magnetic resonance signal and the second element magnetic resonance signal corresponding to the rock sample;

[0055] S13: determining the water-saturated / oil-saturated volume of the rock sample based on the first element magnetic resonance signal intensity of the target solution and the first element magnetic resonance signal intensity of the rock sample; and determining the pore volume of the rock sample based on the second element magnetic resonance signal intensity of the target solution and the second element magnetic resonance signal intensity of the rock sample;

[0056] S14: Determine the rock saturation based on the water-saturated / oil-saturated volume of the rock sample and the pore volume of the rock sample.

[0057] Specifically, the present invention uses two-element magnetic resonance (first magnetic resonance and second magnetic resonance) experiments to determine rock pore fluid saturation. Magnetic resonance experiments of more than two elements may also be used for calculation, which is not limited here.

[0058] The process of preparing the target solution corresponding to the formation water / oil sample of the formation where the rock is located in step S11 can be directly prepared, such as preparing a unit volume of formation water solution or formation oil solution.

[0059] In step S12, a first nuclear magnetic resonance experiment and a second nuclear magnetic resonance experiment are performed on the target solution to determine the magnetic resonance signal intensity of the first element and the magnetic resonance signal intensity of the second element corresponding to the target solution. Considering that the first nuclear magnetic resonance experiment and the second nuclear magnetic resonance experiment are directly performed on the target solution, the signal intensity of the first element corresponding to the first nucleus and the signal intensity of the second element corresponding to the second nucleus are collected. The specific collection process is not limited and can be set according to actual conditions.

[0060] In some embodiments, performing a first nuclear magnetic resonance experiment and a second nuclear magnetic resonance experiment on the target solution to determine the intensity of the first element magnetic resonance signal and the intensity of the second element magnetic resonance signal corresponding to the target solution includes:

[0061] performing a first nuclear magnetic resonance experiment on a unit volume of the target solution to determine a first free induction decay signal of a first element;

[0062] determining a magnetic resonance signal intensity of a first element in a target solution according to a first free induction decay signal of the first element;

[0063] performing a second nuclear magnetic resonance experiment on a unit volume of the target solution to determine a first free induction decay signal of the second element;

[0064] The magnetic resonance signal intensity of the second element in the target solution is determined according to the first free induction decay signal of the second element.

[0065] Specifically, taking a unit volume of formation water solution as a target solution, a first nuclear magnetic resonance experiment is performed on the formation water solution ( 23Na), collect the first free induction decay signal (Free Induction Decay, FID) of the first element. For determining the first element signal intensity, considering that the free induction decay signal of the solution decays slowly, the first sampling point signal is directly collected to slightly determine the signal intensity of the target solution at the initial moment, that is, the target solution 23 The magnetic resonance signal intensity of Na (first element magnetic resonance signal intensity M1). The decay of the FID signal is due to the gradual decay of the transverse magnetic vector of the nucleus to zero due to relaxation. This decay reflects transverse relaxation, while the oscillation of the signal reflects the precession (or precession) of the magnetization intensity in a plane perpendicular to the main magnetic field. In an NMR experiment, the FID signal is plotted as intensity versus time. An inverse Laplace transform yields a plot of the NMR signal intensity versus relaxation time, i.e., the NMR spectrum.

[0066] Similarly, a second NMR was performed ( 1 H) experimentally determining the first free induction decay signal of the second element (H); the process of determining the corresponding second element magnetic resonance signal intensity (M2) based on the first free induction decay signal of the second element is the same as the above process and is not repeated here.

[0067] The process of determining the first element magnetic resonance signal intensity and the second element magnetic resonance signal intensity corresponding to the target solution provided in this embodiment determines the magnetic resonance signal intensity by the first sampling point signal corresponding to the attenuation process of the FID signal, thereby saving acquisition time.

[0068] The process of determining the first element magnetic resonance signal intensity and the second element magnetic resonance signal intensity corresponding to the rock sample in step S12 is based on the process of atomic nuclei returning from a high energy state to a low energy state in the first magnetic resonance experiment and the second magnetic resonance experiment, involving longitudinal relaxation time and transverse relaxation time. In this embodiment, in order to describe the characteristic time parameters of the decay process, a transverse relaxation time spectrum is used. The first element magnetic resonance signal intensity and the second element magnetic resonance signal intensity corresponding to the rock sample determined in the first nuclear magnetic resonance experiment and the second nuclear magnetic resonance experiment respectively are the sum of the curve amplitudes corresponding to the data points on the relaxation spectrum.

[0069] In some embodiments, performing a first nuclear magnetic resonance experiment and a second nuclear magnetic resonance experiment on a rock sample to determine the intensity of a first element magnetic resonance signal and the intensity of a second element magnetic resonance signal corresponding to the rock sample includes:

[0070] Performing a first nuclear magnetic resonance experiment on each rock sample to determine a second free induction decay signal of the first element;

[0071] Inverting the second free induction decay signal of the first element to obtain a relaxation spectrum of the first element;

[0072] The magnetic resonance signal intensity of the first element in the rock sample is obtained by summing the amplitude of the relaxation spectrum of the first element;

[0073] Conducting a second nuclear magnetic resonance experiment on each rock sample to determine a second free induction decay signal of the second element;

[0074] Inverting the second free induction decay signal of the second element to obtain a relaxation spectrum of the second element;

[0075] The magnetic resonance signal intensity of the second element in the rock sample is obtained by adding up the amplitude of the relaxation spectrum of the second element.

[0076] Combined with the above example, the first NMR experiment was conducted on the rock sample (oil-water saturated rock) ( 23 Na), collect the second free induction decay signal of the first element, which is distinguished from the first free induction decay signal of the first element mentioned above because the nuclear magnetic resonance object is different. The relaxation spectrum of the first element is obtained by inverting the second free induction decay signal of the first element ( 23 Na MRI T2 * The relaxation spectrum of the first element is summed up to obtain the first element magnetic resonance signal intensity (M 1,s ).

[0077] Similarly, a second NMR experiment was conducted on the rock sample (oil-water saturated rock) ( 1 H), collect the second free induction decay signal of the second element, which is distinguished from the first free induction decay signal of the second element mentioned above because the nuclear magnetic resonance objects are different. The second free induction decay signal of the second element is inverted to obtain the relaxation spectrum of the second element ( 1 H MRI T2 * The relaxation spectrum of the second element is summed up to obtain the second element magnetic resonance signal intensity (M 2,s ).

[0078] This embodiment provides a process for determining the intensity of the first element magnetic resonance signal and the second element magnetic resonance signal of a rock sample to achieve concentration and volume calculation of corresponding specific components, which is beneficial for providing more possibilities for analyzing different types of molecules.

[0079] In step S13, the saturated water / saturated oil volume of the rock sample is determined. The volume of the saturated water / saturated oil in the rock can be determined through the first element magnetic resonance experiments of the target solution and the rock sample respectively. Therefore, the first element magnetic resonance signal intensity of the target solution and the first element magnetic resonance signal intensity of the rock sample are used for determination.

[0080] In some embodiments, determining the water-saturated / oil-saturated volume of the rock sample based on the first element magnetic resonance signal intensity of the target solution and the first element magnetic resonance signal intensity of the rock sample comprises:

[0081] The first element magnetic resonance signal intensity of the rock sample is divided by the first element magnetic resonance signal intensity of the target solution to determine the saturated water / saturated oil volume of the rock sample.

[0082] Specifically, if the target solution is a solution corresponding to a formation water sample, the saturated water volume of the rock sample will be determined; if the target solution is a solution corresponding to a formation oil sample, the saturated oil volume of the rock sample will be determined. Combined with the above-mentioned formation water solution, the first element magnetic resonance signal intensity of the target solution, i.e., M1, is used here. Assume that the saturated water volume of the rock sample is V w ml, the first element magnetic resonance signal intensity of the rock sample, i.e. M 1,s To obtain the saturated water volume of the rock sample, the first element magnetic resonance signal intensity of the rock sample needs to be divided by the first element magnetic resonance signal intensity of the target solution, that is, (M 1,s ) / (M1) = V w Similarly, the process of determining the volume of saturated oil is the same as that of determining the volume of saturated water, and will not be described in detail here.

[0083] The process for determining the volume of saturated water / saturated oil provided in this embodiment is to achieve the balance of Na ions or C ions by dividing the first element magnetic resonance signal intensity of the rock sample by the first element magnetic resonance signal intensity of the target solution under different unit volumes.

[0084] In step S13, the pore volume of the rock sample is determined based on the second element magnetic resonance signal intensity of the target solution and the second element magnetic resonance signal intensity of the rock sample. In some embodiments, determining the pore volume of the rock sample based on the second element magnetic resonance signal intensity of the target solution and the second element magnetic resonance signal intensity of the rock sample includes:

[0085] The pore volume of the rock sample is determined by dividing the second element magnetic resonance signal intensity of the rock sample by the second element magnetic resonance signal intensity of the target solution.

[0086] Specifically, based on the examples in the above embodiments, according to the formation water solution and rock 1H magnetic resonance experiment, the pore volume is:

[0087] ;

[0088] The process for determining the pore volume of the rock sample provided in this embodiment is to directly determine the pore volume by dividing the second element magnetic resonance signal intensity in the rock sample by the second element magnetic resonance signal intensity in the target solution, since the target solution and the rock pore fluid have the same hydrogen index, thereby simplifying the determination process.

[0089] In step S14, the saturation of water and oil is determined by using the saturated water / saturated oil volume and the pore volume, thereby improving the accuracy of determining the saturated water.

[0090] An embodiment of the present invention provides a method for determining rock pore fluid saturation based on multi-nuclear magnetic resonance, including: obtaining a target solution corresponding to a formation water / oil sample of a formation in which the rock is located and a rock sample saturated with oil and water; performing a first nuclear magnetic resonance experiment and a second nuclear magnetic resonance experiment on the target solution, respectively, to determine the first element magnetic resonance signal intensity and the second element magnetic resonance signal intensity corresponding to the target solution; performing a first nuclear magnetic resonance experiment and a second nuclear magnetic resonance experiment on the rock sample, respectively, to determine the first element magnetic resonance signal intensity and the second element magnetic resonance signal intensity corresponding to the rock sample; determining the water-saturated / oil-saturated volume of the rock sample based on the first element magnetic resonance signal intensity of the target solution and the first element magnetic resonance signal intensity of the rock sample; and determining the pore volume of the rock sample based on the second element magnetic resonance signal intensity of the target solution and the second element magnetic resonance signal intensity of the rock sample; and determining the saturation of the rock based on the water-saturated / oil-saturated volume of the rock sample and the pore volume of the rock sample. The present invention determines the saturated water / saturated oil volume and the total pore volume of a rock sample by performing a first nuclear magnetic resonance experiment using a first element and a second nuclear magnetic resonance experiment using a second element, and determines the saturation of the rock pore fluid through multi-nuclear magnetic resonance experiments, thereby effectively avoiding the problem of inaccurate oil-water saturation calculation due to overlapping oil and water signals in a magnetic resonance relaxation spectrum, and correspondingly improving the accuracy of oil-water saturation calculation.

[0091] In some embodiments, the first element is 23 When Na is present, the rock saturation is determined based on the saturated water volume and pore volume of the rock sample, including:

[0092] The water saturation of the rock sample is determined by dividing the saturated water volume of the rock sample by the pore volume of the rock sample;

[0093] The oil saturation of the rock sample is determined by subtracting 1 from the water saturation of the rock sample.

[0094] Specifically, in combination with the above embodiment, taking the formation aqueous solution as the target solution, the corresponding rock fluid saturation, the formula for the water saturation in the rock is as follows:

[0095] ;

[0096] The formula corresponding to oil saturation is:

[0097] ;

[0098] The determination process of water and oil saturation provided in this embodiment is based on the above 23 Na and 1 The first nuclear magnetic resonance experiment and the second nuclear magnetic resonance experiment corresponding to the H element are realized respectively, thereby improving the accuracy of the saturation.

[0099] In other embodiments, the first element is 13 When C is used, the rock saturation is determined based on the saturated oil volume and pore volume of the rock sample, including:

[0100] The oil saturation of the rock sample is determined by dividing the saturated oil volume of the rock sample by the pore volume of the rock sample;

[0101] The water saturation of the rock sample is determined by subtracting 1 from the oil saturation of the rock sample.

[0102] In combination with the above embodiment, taking the bottom crude oil as the target solution, the corresponding rock fluid saturation, the formula for the oil saturation in the rock is as follows:

[0103] ;

[0104] in, The first element is 13 The oil saturation corresponding to the C element is is the first element magnetic resonance signal intensity of the rock sample ( 13 C element magnetic resonance signal intensity); is the second element magnetic resonance signal intensity of the target solution; is the second element magnetic resonance signal intensity of the rock sample; is the first element magnetic resonance signal intensity of the target solution ( 13 C element magnetic resonance signal intensity).

[0105] The formula corresponding to water saturation is:

[0106] ;

[0107] in, The first element is13 The corresponding water saturation when element C is used.

[0108] The process of determining water and oil saturation provided in this embodiment is based on the above 13 C element and 1 The first nuclear magnetic resonance and the second nuclear magnetic resonance corresponding to the H element are realized respectively, thereby improving the accuracy of saturation.

[0109] The above describes in detail various embodiments corresponding to the method for determining rock pore fluid saturation based on multi-nuclear magnetic resonance. On this basis, the present invention also discloses a device for determining rock pore fluid saturation based on multi-nuclear magnetic resonance corresponding to the above method. Figure 2 This is a structural diagram of a device for determining rock pore fluid saturation based on multi-nuclear magnetic resonance provided by an embodiment of the present invention. Figure 2 As shown, the rock pore fluid saturation determination device based on multi-nuclear magnetic resonance includes:

[0110] An acquisition module 11 is used to obtain a target solution corresponding to a formation water / oil sample of the formation where the rock is located and a rock sample saturated with oil and water;

[0111] The first determination module 12 is configured to perform a first nuclear magnetic resonance experiment and a second nuclear magnetic resonance experiment on the target solution, respectively, to determine the intensity of the first element magnetic resonance signal and the second element magnetic resonance signal corresponding to the target solution; and perform a first nuclear magnetic resonance experiment and a second nuclear magnetic resonance experiment on the rock sample, respectively, to determine the intensity of the first element magnetic resonance signal and the second element magnetic resonance signal corresponding to the rock sample;

[0112] a second determination module 13, configured to determine the water-saturated / oil-saturated volume of the rock sample based on the first element magnetic resonance signal intensity of the target solution and the first element magnetic resonance signal intensity of the rock sample; and to determine the pore volume of the rock sample based on the second element magnetic resonance signal intensity of the target solution and the second element magnetic resonance signal intensity of the rock sample;

[0113] The third determination module 14 is configured to determine the rock saturation according to the water-saturated / oil-saturated volume of the rock sample and the pore volume of the rock sample.

[0114] Since the embodiments of the device part correspond to the above embodiments, the embodiments of the device part please refer to the description of the embodiments of the method part, which will not be repeated here.

[0115] For an introduction to the rock pore fluid saturation determination device based on multi-nuclear magnetic resonance provided by the present invention, please refer to the above method embodiment. The present invention will not be repeated here. It has the same beneficial effects as the above-mentioned rock pore fluid saturation determination method based on multi-nuclear magnetic resonance.

[0116] Figure 3 A structural diagram of a device for determining rock pore fluid saturation based on multi-nuclear magnetic resonance provided by an embodiment of the present invention, such as Figure 3 As shown, the device includes:

[0117] Memory 21, for storing computer programs;

[0118] The processor 22 is configured to implement the steps of the method for determining rock pore fluid saturation based on multi-nuclear magnetic resonance when executing a computer program.

[0119] The device for determining rock pore fluid saturation based on multi-nuclear magnetic resonance provided in this embodiment may include but is not limited to a smart phone, a tablet computer, a laptop computer, or a desktop computer.

[0120] The processor 22 may include one or more processing cores, such as a quad-core processor or an octa-core processor. The processor 22 may be implemented in at least one of the following hardware forms: a digital signal processor (DSP), a field-programmable gate array (FPGA), or a programmable logic array (PLA). The processor 22 may also include a main processor and a coprocessor. The main processor is a processor for processing data in the awake state, also known as a central processing unit (CPU); the coprocessor is a low-power processor for processing data in the standby state. In some embodiments, the processor 22 may be integrated with a graphics processing unit (GPU), which is responsible for rendering and drawing the content required to be displayed on the display screen. In some embodiments, the processor 22 may also include an artificial intelligence (AI) processor, which is responsible for processing computing operations related to machine learning.

[0121] The memory 21 may include one or more computer-readable storage media, which may be non-transitory. The memory 21 may also include high-speed random access memory, and non-volatile memory, such as one or more disk storage devices, flash memory storage devices. In this embodiment, the memory 21 is at least used to store the following computer program 211, wherein, after the computer program is loaded and executed by the processor 22, it can implement the relevant steps of the method for determining the rock pore fluid saturation based on multi-nuclear magnetic resonance disclosed in any of the aforementioned embodiments. In addition, the resources stored in the memory 21 may also include an operating system 212 and data 213, etc., and the storage method may be temporary storage or permanent storage. Among them, the operating system 212 may include Windows, Unix, Linux, etc. The data 213 may include but is not limited to data involved in the method for determining the rock pore fluid saturation based on multi-nuclear magnetic resonance, etc.

[0122] In some embodiments, the rock pore fluid saturation determination based on multi-nuclear magnetic resonance may further include a display screen 23 , an input and output interface 24 , a communication interface 25 , a power supply 26 , and a communication bus 27 .

[0123] Those skilled in the art will understand that Figure 3 The structure shown in the figure does not constitute a limitation on the multi-core based rock pore fluid saturation determination device, and may include more or fewer components than shown in the figure.

[0124] The processor 22 calls the instructions stored in the memory 21 to implement the method for determining the rock pore fluid saturation based on multi-nuclear magnetic resonance provided by any of the above embodiments.

[0125] For an introduction to the rock pore fluid saturation determination device based on multi-nuclear magnetic resonance provided by the present invention, please refer to the above method embodiment. The present invention will not be repeated here. It has the same beneficial effects as the above-mentioned rock pore fluid saturation determination method based on multi-nuclear magnetic resonance.

[0126] Furthermore, the present invention also provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by the processor 22, the steps of the method for determining the rock pore fluid saturation based on multi-nuclear magnetic resonance are implemented as described above.

[0127] It is understood that if the methods in the above embodiments are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the portion that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and executes all or part of the steps of the methods in each embodiment of the present invention. The aforementioned storage medium includes various media that can store program code, such as a USB flash drive, a mobile hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0128] For an introduction to a computer-readable storage medium provided by the present invention, please refer to the above method embodiment, and the present invention will not be repeated here. It has the same beneficial effects as the above-mentioned method for determining rock pore fluid saturation based on multi-nuclear magnetic resonance.

[0129] The above is a detailed introduction to the method and device for determining the fluid saturation of rock pores based on multi-nuclear magnetic resonance provided by the present invention. The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the various 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 description. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, the present invention can also be improved and modified in several ways, and these improvements and modifications also fall within the scope of protection of the present invention.

[0130] It should also be noted that, in this specification, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus comprising the element.

Claims

1. A method for determining rock pore fluid saturation based on multi-nuclear magnetic resonance, characterized in that: include: Obtain target solution corresponding to formation water / oil sample of the formation where the rock is located and rock sample saturated with oil and water; Performing a first nuclear magnetic resonance experiment and a second nuclear magnetic resonance experiment on the target solution, respectively, to determine the first element magnetic resonance signal intensity and the second element magnetic resonance signal intensity corresponding to the target solution; performing a first nuclear magnetic resonance experiment and a second nuclear magnetic resonance experiment on the rock sample, respectively, to determine the first element magnetic resonance signal intensity and the second element magnetic resonance signal intensity corresponding to the rock sample; Determining the saturated water / saturated oil volume of the rock sample based on the first element magnetic resonance signal intensity of the target solution and the first element magnetic resonance signal intensity of the rock sample; and determining the pore volume of the rock sample based on the second element magnetic resonance signal intensity of the target solution and the second element magnetic resonance signal intensity of the rock sample; The saturation of the rock is determined based on the water-saturated / oil-saturated volume of the rock sample and the pore volume of the rock sample.

2. The method for determining rock pore fluid saturation based on multi-nuclear magnetic resonance according to claim 1, characterized in that: Performing a first nuclear magnetic resonance experiment and a second nuclear magnetic resonance experiment on the target solution respectively to determine the first element magnetic resonance signal intensity and the second element magnetic resonance signal intensity corresponding to the target solution, comprising: Performing a first nuclear magnetic resonance experiment on a unit volume of the target solution to determine a first free induction decay signal of a first element; determining a magnetic resonance signal intensity of a first element in the target solution according to a first free induction decay signal of the first element; performing a second nuclear magnetic resonance experiment on a unit volume of the target solution to determine a first free induction decay signal of a second element; The magnetic resonance signal intensity of the second element in the target solution is determined according to the first free induction decay signal of the second element.

3. The method for determining rock pore fluid saturation based on multi-nuclear magnetic resonance according to claim 2, characterized in that: Performing a first nuclear magnetic resonance experiment and a second nuclear magnetic resonance experiment on the rock sample respectively to determine the intensity of the first element magnetic resonance signal and the intensity of the second element magnetic resonance signal corresponding to the rock sample, including: Performing a first nuclear magnetic resonance experiment on each of the rock samples to determine a second free induction decay signal of the first element; Inverting the second free induction decay signal of the first element to obtain a relaxation spectrum of the first element; performing summing processing based on the amplitude of the relaxation spectrum of the first element to obtain the magnetic resonance signal intensity of the first element in the rock sample; performing a second nuclear magnetic resonance experiment on each of the rock samples to determine a second free induction decay signal of a second element; Inverting the second free induction decay signal of the second element to obtain a relaxation spectrum of the second element; The magnetic resonance signal intensity of the second element in the rock sample is obtained by summing up the amplitude of the relaxation spectrum of the second element.

4. The method for determining rock pore fluid saturation based on multi-nuclear magnetic resonance according to any one of claims 1 to 3, characterized in that: Determining the saturated water / saturated oil volume of the rock sample according to the first element magnetic resonance signal intensity of the target solution and the first element magnetic resonance signal intensity of the rock sample comprises: The first element magnetic resonance signal intensity of the rock sample is divided by the first element magnetic resonance signal intensity of the target solution to determine the saturated water / saturated oil volume of the rock sample.

5. The method for determining rock pore fluid saturation based on multi-nuclear magnetic resonance according to claim 4, characterized in that: Determining the pore volume of the rock sample according to the second element magnetic resonance signal intensity of the target solution and the second element magnetic resonance signal intensity of the rock sample includes: The pore volume of the rock sample is determined by dividing the second element magnetic resonance signal intensity of the rock sample by the second element magnetic resonance signal intensity of the target solution.

6. The method for determining rock pore fluid saturation based on multi-nuclear magnetic resonance according to claim 5, characterized in that: The first element is 23 When the Na element is present, the saturation of the rock is determined according to the saturated water volume of the rock sample and the pore volume of the rock sample, including: Determine the water saturation of the rock sample by dividing the saturated water volume of the rock sample by the pore volume of the rock sample; The oil saturation of the rock sample is determined by subtracting 1 from the water saturation of the rock sample.

7. The method for determining rock pore fluid saturation based on multi-nuclear magnetic resonance according to claim 5, characterized in that: The first element is 13 When the C element is present, the saturation of the rock is determined according to the saturated oil volume of the rock sample and the pore volume of the rock sample, including: Determine the oil saturation of the rock sample by dividing the saturated oil volume of the rock sample by the pore volume of the rock sample; The water saturation of the rock sample is determined by subtracting 1 from the oil saturation of the rock sample.

8. A device for determining rock pore fluid saturation based on multi-nuclear magnetic resonance, characterized in that: include: An acquisition module is used to obtain a target solution corresponding to a formation water / oil sample of the formation where the rock is located and a rock sample saturated with oil and water; A first determination module is configured to perform a first nuclear magnetic resonance experiment and a second nuclear magnetic resonance experiment on the target solution, respectively, to determine the intensity of the first element magnetic resonance signal and the second element magnetic resonance signal corresponding to the target solution; and perform a first nuclear magnetic resonance experiment and a second nuclear magnetic resonance experiment on the rock sample, respectively, to determine the intensity of the first element magnetic resonance signal and the second element magnetic resonance signal corresponding to the rock sample; a second determination module, configured to determine the water-saturated / oil-saturated volume of the rock sample based on the first element magnetic resonance signal intensity of the target solution and the first element magnetic resonance signal intensity of the rock sample; and to determine the pore volume of the rock sample based on the second element magnetic resonance signal intensity of the target solution and the second element magnetic resonance signal intensity of the rock sample; The third determination module is used to determine the saturation of the rock according to the saturated water / saturated oil volume of the rock sample and the pore volume of the rock sample.

9. A multi-core based rock pore fluid saturation determination device, characterized in that: include: Memory for storing computer programs; A processor, configured to implement the steps of the method for determining rock pore fluid saturation based on multi-nuclear magnetic resonance as described in any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of the method for determining rock pore fluid saturation based on multi-nuclear magnetic resonance as described in any one of claims 1 to 7.

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