Rock pore fluid saturation determination method and device based on multi-nuclear magnetic resonance

Abstract

The invention discloses a rock pore fluid saturation determination method and device based on multi-nuclear magnetic resonance, and relates to the technical field of oil-gas exploration. A first nuclear magnetic resonance experiment is carried out through the first element, a second nuclear magnetic resonance experiment is carried out through the second element, the saturated water / saturated oil volume and the pore total volume of the rock sample are determined, and the saturation degree of the rock pore fluid is determined in a multi-nuclear magnetic resonance mode. The problem that oil and water signals in the magnetic resonance relaxation spectrum are overlapped to calculate the oil-water saturation inaccurately is effectively solved, and the oil-water saturation calculation precision is correspondingly improved.

Description

Technical Field

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

[0002] The oil and gas saturation of the reservoir directly determines the resource volume and potential economic value of the oil and gas reservoir, and is the key data in the commercial feasibility analysis of oil and gas fields. At present, magnetic resonance logging is an important geophysical logging method, which can be used to evaluate the saturation of formation pore fluids. However, with the continuous deepening of exploration and development, the amount of conventional reservoir resources is decreasing, and the exploration, development and utilization of unconventional reservoir oil and gas resources are particularly important.

[0003] Unconventional reservoirs have low porosity and well-developed micro-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 issue that technical personnel in this field urgently need to solve. 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 different fluid signals in the current magnetic resonance relaxation spectrum are seriously overlapped, resulting in reduced accuracy of rock pore fluid identification and saturation.

[0006] In order 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 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;

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

[0009] Determine 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; and determine 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;

[0010] The saturation of the rock is determined based on the saturated water / saturated oil 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 the magnetic resonance signal intensity of the first element in the target solution according to the 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 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 summation processing according to 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 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 adding 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] On the other hand, 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] Dividing the saturated oil volume of the rock sample by the pore volume of the rock sample to determine the oil saturation 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] In order to solve the above technical problems, the present invention also provides a device for determining rock pore fluid saturation based on multi-nuclear magnetic resonance, comprising:

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

[0035] A first determination module is used to perform 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; and to perform 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;

[0036] A second determination module is used to determine 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; and to determine 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;

[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] In order to solve the above technical problems, the present invention also 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 the rock pore fluid saturation based on multi-nuclear magnetic resonance are implemented.

[0042] The present invention provides a method for determining the saturation of rock pore fluid 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 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 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; and 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; and determining 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. 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 with a first element and a second nuclear magnetic resonance experiment with a second element, and determines the saturation of the rock pore fluid by a multi-nuclear magnetic resonance experiment, thereby effectively avoiding the problem of inaccurate calculation of oil and water saturation due to overlap of oil and water signals in a magnetic resonance relaxation spectrum, and correspondingly improving the calculation accuracy of the oil and water saturation.

[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 briefly introduces 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 paying 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 in an embodiment of the present invention. DETAILED DESCRIPTION

[0048] 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.

[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 are seriously overlapped, resulting in reduced accuracy in rock pore fluid identification and saturation.

[0050] In order to enable those skilled in the art to better understand the solution of the present invention, the present invention is further described in detail below in conjunction with 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 H2D magnetic resonance technology can simultaneously collect two types of relaxation information of rock pore fluids, 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 the blind source separation method is used to divide the fluid signal region and realize the calculation of fluid saturation, the premise of the application of these methods is that the relaxation time of the pore fluid 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 the saturation of rock pore fluid based on multi-nuclear magnetic resonance provided by the present invention can solve the above technical problems.

[0052] Figure 1 A flowchart 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 a 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 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 to determine the first element magnetic resonance signal intensity and the second element magnetic resonance signal intensity corresponding to the rock sample;

[0055] S13: 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; and 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;

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

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

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

[0059] In step S12, the first nuclear magnetic resonance experiment and the second nuclear magnetic resonance experiment are respectively performed on the target solution to determine the magnetic resonance signal intensity of the first element and the second element corresponding to the target solution, considering that the target solution directly performs the first nuclear magnetic resonance experiment and the second nuclear magnetic resonance experiment to collect the signal intensity of the first element corresponding to the first nucleus and the signal intensity of the second element of the second nucleus. 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 respectively to determine the first element magnetic resonance signal intensity and the second element magnetic resonance signal intensity 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 the 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 signal intensity of the first element, considering that the free induction decay signal of the solution decays slowly, the signal of the first sampling point is directly collected to slightly determine the signal intensity of the target solution at the initial moment, that is, the signal intensity of the target solution 23 The magnetic resonance signal intensity of Na (the first element magnetic resonance signal intensity M1). The attenuation process of the FID signal is due to the gradual decay of the transverse magnetization vector of the atomic nucleus to zero due to the relaxation effect. This attenuation reflects the relaxation phenomenon in the transverse direction, and the oscillation of the signal reflects the precession (spin) of the magnetization intensity in the plane perpendicular to the main magnetic field. In the nuclear magnetic resonance experiment, the FID signal is a curve of intensity variation with time. After the inverse Laplace transform, the curve of the nuclear magnetic resonance signal intensity variation with the relaxation time can be obtained, that is, the nuclear magnetic resonance spectrum.

[0066] Similarly, a second NMR ( 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) according to the first free induction decay signal of the second element is the same as the above process and will not be repeated here.

[0067] The present embodiment provides a process for determining the intensity of the first element magnetic resonance signal and the intensity of the second element magnetic resonance signal corresponding to the target solution, wherein the intensity of the magnetic resonance signal is determined by the first sampling point signal corresponding to the attenuation process of the FID signal, so as to save acquisition time.

[0068] The determination process of 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 the atomic nucleus returning from the high energy state to the low energy state in the first magnetic resonance experiment and the second magnetic resonance experiment, involving the longitudinal relaxation time and the transverse relaxation time. In this embodiment, in order to describe the characteristic time parameters of the decay process, the 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 on the rock sample 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 respectively to determine the intensity of a first element magnetic resonance signal and an intensity of a second element magnetic resonance signal corresponding to the rock sample includes:

[0070] Performing a first nuclear magnetic resonance experiment on the rock samples 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 adding up the amplitude of the relaxation spectrum of the first element;

[0073] Conducting a second nuclear magnetic resonance experiment on the rock samples 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] Combining the above examples, 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, and distinguish it from the first free induction decay signal of the first element mentioned above, because the NMR objects are 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, and distinguish it from the first free induction decay signal of the second element mentioned above, because the NMR 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 magnetic resonance signal intensity (M 2,s ).

[0078] The present 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] The saturated water / saturated oil volume of the rock sample in step S13 can be determined by first element magnetic resonance experiments of the target solution and the rock sample, so 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 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:

[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, which 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 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. In some embodiments, the pore volume of the rock sample is determined 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, including:

[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, in combination with the examples in the above embodiments, according to the formation water solution and the 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 hydrogen index of the target solution and the rock pore fluid is the same, 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] A method for determining rock pore fluid saturation based on multi-nuclear magnetic resonance provided by an embodiment of the present invention includes: 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 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; and 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; and determining 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. 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 with a first element and a second nuclear magnetic resonance experiment with a second element, and determines the saturation of the rock pore fluid by a multi-nuclear magnetic resonance experiment, thereby effectively avoiding the problem of inaccurate calculation of oil and water saturation due to overlap of oil and water signals in a magnetic resonance relaxation spectrum, and correspondingly improving the calculation accuracy of the oil and water saturation.

[0091] In some embodiments, the first element is 23 When Na is measured, the rock saturation is determined based on the saturated water volume of the rock sample and the 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 formula for the water saturation in the rock in the corresponding rock fluid saturation 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 some other embodiments, the first element is 13 When C element is measured, the saturation of the rock is determined based on the saturated oil volume of the rock sample and the 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 formula of the oil saturation in the rock in the corresponding rock fluid saturation 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 determination process of 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 The structure 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 acquire a target solution corresponding to a formation water / oil sample of a formation where the rock is located and a rock sample saturated with oil and water;

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

[0112] A second determination module 13 is used to determine 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; and to determine 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;

[0113] The third determination module 14 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.

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

[0115] For an introduction to a device for determining rock pore fluid saturation based on multi-nuclear magnetic resonance 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 method for determining rock pore fluid saturation based on multi-nuclear magnetic resonance.

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

[0117] A memory 21, used for storing computer programs;

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

[0119] The rock pore fluid saturation determination device 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] Among them, the processor 22 may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor 22 may be implemented in at least one hardware form of a digital signal processor (DSP), a field-programmable gate array (FPGA), and 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 to be displayed on the display screen. In some embodiments, the processor 22 may also include an artificial intelligence (AI) processor, which is used to process 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 a high-speed random access memory, and a 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 saturation of rock pore fluid 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 saturation of rock pore fluid based on multi-nuclear magnetic resonance, etc.

[0122] In some embodiments, the rock pore fluid saturation determination based on multi-nuclear magnetic resonance may also 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 can 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 less components than those 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 a device for determining rock pore fluid saturation based on multi-nuclear magnetic resonance 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 method for determining rock pore fluid saturation based on multi-nuclear magnetic resonance.

[0126] Furthermore, the present invention also provides a computer-readable storage medium, on which a computer program is stored. 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 understandable that if the method in the above embodiment is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium to execute all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk and other media that can store program codes.

[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 a 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 embodiments can be referenced 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, several improvements and modifications can be made to the present invention, 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 such actual relationship or order between these entities or operations. Moreover, the terms "comprises", "comprising" 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, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

Claims

1. A method for determining rock pore fluid saturation based on multi-nuclear magnetic resonance, characterized in that: include: 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; Performing a first nuclear magnetic resonance experiment and a second nuclear magnetic resonance experiment on the target solution 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 to determine the first element magnetic resonance signal intensity and the second element magnetic resonance signal intensity corresponding to the rock sample; Determine 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; and determine 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; The saturation of the rock is determined based on the saturated water / saturated oil 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, including: 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 the magnetic resonance signal intensity of the first element in the target solution according to the 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 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 summation processing according to 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 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 adding 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 comprises: 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: Dividing the saturated oil volume of the rock sample by the pore volume of the rock sample to determine the oil saturation 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, used to acquire a target solution corresponding to a formation water / oil sample of a formation where the rock is located and a rock sample saturated with oil and water; A first determination module is used to perform 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; and to perform 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; A second determination module is used to determine 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; and to determine 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; 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 is used 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, and 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 as described in any one of claims 1 to 7 are implemented.

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