1. A fractured tight reservoir physical model, the model comprising:

a substrate;

the crack simulator is uniformly wrapped on the outer side of the substrate.

2. The fractured tight reservoir physical model of claim 1, wherein the permeability of the simulated fracture is adjusted by adjusting the particle size of the fracture mimic.

3. The fractured tight reservoir physical model of claim 1, wherein the matrix is a natural core.

4. The fractured tight reservoir physical model of claim 1, wherein the fractured simulator is quartz sand.

5. A system for calculating the recovery factor of a physical model of a fractured tight reservoir according to any one of claims 1 to 4, comprising:

a fractured tight reservoir physical model;

the holder cylinder is used for placing the fractured compact reservoir physical model;

the connectors are detachably connected to the holder cylinder, and a through hole is formed in each connector along the radial direction of the holder cylinder;

the fluid channels are communicated with the inside of the clamp holder cylinder body through the through holes respectively, and the outer diameter of each fluid channel is equal to the inner diameter of each through hole;

the nuclear magnetic resonance spectrometer probe is arranged on the outer periphery of the holder cylinder.

6. A method of calculating a recovery factor, comprising:

loading the physical model of the fractured compact reservoir into a holder cylinder;

vacuumizing the physical model of the fractured compact oil reservoir, and further performing saturated oil treatment;

injecting a displacement medium into the fractured compact reservoir physical model treated by saturated oil at a constant speed;

the recovery factor was calculated by monitoring the nmr T2 spectral signals within the model with an nmr while injecting the displacement medium.

7. The method of claim 6, wherein loading the fractured-tight reservoir physical model into the holder cylinder comprises:

fixing the substrate on a joint at one end of the holder cylinder, wherein the central axis of the substrate is superposed with the central axis of the holder cylinder;

filling the fracture simulator into a holder cylinder containing the substrate, so that the fracture simulator is filled with the substrate and a cavity of the holder cylinder;

and closing and compacting the other end joint of the gripper cylinder.

8. The method for calculating oil recovery factor of claim 6, wherein oil recovery factor is calculated by equation (1):

wherein F is the recovery factor, A₀Is the area of the peak of the NMR signal at the initial time, A_iThe peak area of the NMR signal at time i.

9. The method of claim 6, further comprising:

respectively scanning the matrix and the fractured compact reservoir physical model through a nuclear magnetic resonance instrument to respectively obtain nuclear magnetic resonance T2 spectrum signals of the matrix and the fractured compact reservoir physical model;

distinguishing the matrix from the fracture analogue by comparing nuclear magnetic resonance T2 spectrum signals, and further determining nuclear magnetic resonance T2 relaxation time ranges of the matrix and the fracture analogue respectively;

and determining nuclear magnetic resonance T2 spectrum signals of the matrix and the fracture simulation body in the physical model of the fractured compact reservoir at different injection times according to the relaxation time range of the nuclear magnetic resonance T2, and further respectively calculating the recovery ratio of the matrix and the fracture simulation body.

10. The method for recovery of oil according to claim 9, wherein the recovery of the matrix is calculated from the nuclear magnetic resonance T2 spectrum of the matrix by equation (2):

calculating the recovery ratio of the fracture simulation body according to the nuclear magnetic resonance T2 spectrum of the fracture simulation body by the formula (3):

wherein, F_SubstrateFor the recovery of the base fraction of crude oil, A_{0, matrix}The peak area of the nuclear magnetic resonance signal of the substrate portion at the initial time, A_{i, substrate}The peak area of the nuclear magnetic resonance signal of the substrate part at time i, F_{Crack simulator}Recovery of crude oil for the fracture analogue part, A_{0, crack simulator}The peak area of the nuclear magnetic resonance signal of the fracture analogue part at the initial time A_{i, crack simulator}The peak area of the nuclear magnetic resonance signal of the body part is simulated for the crack at time i.

Background

The compact oil reservoir mainly refers to a reservoir with the permeability of less than 1 millidarcy, has the characteristics of ultra-low porosity and ultra-low permeability, generally has no natural productivity, and is developed mainly by means of horizontal well multi-stage fracturing. In the indoor physical simulation process, in order to better simulate the development process of the tight oil reservoir, a fractured tight oil reservoir physical model containing fractured fractures and an experimental method need to be constructed. Meanwhile, the porosity of the compact core is low and is generally less than 10%, the indoor physical simulation saturated oil quantity is small, and the experimental method for measuring the oil quantity by volume has low precision and poor accuracy. At present, a plurality of scholars identify the oil quantity change in the tight oil reservoir through a nuclear magnetic resonance technology, and further simulate the development process of the exhaustion, water injection or gas injection of the tight oil reservoir.

In the prior art, compact core seam making mainly comprises two methods: firstly, the method comprises the following steps: forming a crack in the rock core by adopting a splitting or cutting method; secondly, the method comprises the following steps: the core is divided into a plurality of parts by adopting a splitting or cutting method, and then other materials are filled among the parts to simulate the properties of the cracks. However, when the fractured compact rock core constructed by the two methods is loaded into a holder for a flow experiment, the external part of the rock core is applied with confining pressure, the constructed fracture can generate a closing effect under the action of the confining pressure, and the larger the confining pressure is, the longer the experiment time is, and the more obvious the closing is. In the experimental process, the closing effect is difficult to be accurately measured, and the accuracy of the experimental result is further influenced. The existing physical model of the fractured tight oil reservoir cannot evaluate the recovery ratio of the fractured part because the shape and the property of the fracture can change in the experimental process, and the recovery ratio of the whole model is generally calculated by taking a matrix and the fracture as a whole.

Therefore, there is a need for developing a physical model of fractured tight reservoir, a system and a method for calculating oil recovery.

The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

Disclosure of Invention

The invention provides a physical model of a fractured tight oil reservoir, a recovery ratio calculation system and a recovery ratio calculation method, which can obtain the flow characteristics of crude oil in fractured fractures and matrixes by establishing the physical model of the fractured tight oil reservoir and developing the flow experiment of the crude oil in the presence of the fractures and the matrixes, respectively calculate the recovery ratio of the fractures and the matrixes and evaluate the oil displacement effect of different displacement media in the presence of the fractured fractures and the matrixes.

According to a first aspect of the invention, a physical model of a fractured tight reservoir is provided, which is characterized by comprising: a substrate; the crack simulator is uniformly wrapped on the outer side of the substrate.

Preferably, the permeability of the simulated fracture is adjusted by adjusting the particle size of the fracture mimic.

Preferably, the matrix is a natural core.

Preferably, the fracture simulator is quartz sand.

According to a second aspect of the present invention, there is provided a recovery factor calculation system, comprising: a fractured tight reservoir physical model; the holder cylinder is used for placing the fractured compact reservoir physical model; the connectors are detachably connected to the holder cylinder, and a through hole is formed in each connector along the radial direction of the holder cylinder; the fluid channels are communicated with the inside of the clamp holder cylinder body through the through holes respectively, and the outer diameter of each fluid channel is equal to the inner diameter of each through hole; the nuclear magnetic resonance spectrometer probe is arranged on the outer periphery of the holder cylinder.

Preferably, the outer diameter of the fitting is equal to the inner diameter of the gripper cylinder.

According to a third aspect of the present invention, there is provided a method of calculating a recovery factor, comprising: loading the physical model of the fractured compact reservoir into a holder cylinder; vacuumizing the physical model of the fractured compact oil reservoir, and further performing saturated oil treatment; injecting a displacement medium into the fractured compact reservoir physical model treated by saturated oil at a constant speed; the recovery factor was calculated by monitoring the nmr T2 spectral signals within the model with an nmr while injecting the displacement medium.

Preferably, loading the fractured tight reservoir physical model into the holder cylinder comprises: fixing the substrate on a joint at one end of the holder cylinder, wherein the central axis of the substrate is superposed with the central axis of the holder cylinder; filling the fracture simulator into a holder cylinder containing the substrate, so that the fracture simulator is filled with the substrate and a cavity of the holder cylinder; and closing and compacting the other end joint of the gripper cylinder.

Preferably, the recovery factor is calculated by equation (1):

wherein F is the recovery factor, A₀Is the area of the peak of the NMR signal at the initial time, A_iThe peak area of the NMR signal at time i.

Preferably, the method further comprises the following steps: respectively scanning the matrix and the fractured compact reservoir physical model through a nuclear magnetic resonance instrument to respectively obtain nuclear magnetic resonance T2 spectrum signals of the matrix and the fractured compact reservoir physical model; distinguishing the matrix from the fracture analogue by comparing nuclear magnetic resonance T2 spectrum signals, and further determining nuclear magnetic resonance T2 relaxation time ranges of the matrix and the fracture analogue respectively; and determining nuclear magnetic resonance T2 spectrum signals of the matrix and the fracture simulation body in the physical model of the fractured compact reservoir at different injection times according to the relaxation time range of the nuclear magnetic resonance T2, and further respectively calculating the recovery ratio of the matrix and the fracture simulation body.

Preferably, the recovery factor of the matrix is calculated by equation (2) from the nuclear magnetic resonance T2 spectrum of the matrix:

calculating the recovery ratio of the fracture simulation body according to the nuclear magnetic resonance T2 spectrum of the fracture simulation body by the formula (3):

wherein, F_SubstrateFor the recovery of the base fraction of crude oil, A_{0, matrix}The peak area of the nuclear magnetic resonance signal of the substrate portion at the initial time, A_{i, substrate}The peak area of the nuclear magnetic resonance signal of the substrate part at time i, F_{Crack simulator}Recovery of crude oil for the fracture analogue part, A_{0, crack simulator}The peak area of the nuclear magnetic resonance signal of the fracture analogue part at the initial time A_{i, crack simulator}The peak area of the nuclear magnetic resonance signal of the body part is simulated for the crack at time i.

The method and apparatus of the present invention have other features and advantages which will be apparent from or are set forth in detail in the accompanying drawings and the following detailed description, which are incorporated herein, and which together serve to explain certain principles of the invention.

Drawings

The above and other objects, features and advantages of the present invention will become more apparent by describing in more detail exemplary embodiments thereof with reference to the attached drawings, in which like reference numerals generally represent like parts.

FIG. 1 shows a schematic of a fractured tight reservoir physical model according to one embodiment of the invention.

FIG. 2 illustrates an A-A' directional cross-sectional view of a physical model of a fractured tight reservoir according to one embodiment of the invention.

FIG. 3 shows a B-B' directional cross-sectional view of a physical model of a fractured tight reservoir according to an embodiment of the invention.

Fig. 4 shows a flow chart of the steps of the method of oil recovery calculation according to the invention.

FIG. 5 shows a schematic of a recovery factor calculation system according to one embodiment of the present invention.

Figure 6 shows a schematic representation of a final nuclear magnetic resonance T2 spectrogram according to an embodiment of the present invention.

Fig. 7 shows a schematic diagram of a nuclear magnetic resonance T2 spectrum of a physical model of a natural core and fractured tight reservoir according to an embodiment of the invention.

Fig. 8 shows a schematic diagram of a nuclear magnetic resonance T2 spectrum of a natural core and quartz sand in a physical model of a fractured tight reservoir according to an embodiment of the invention.

Description of reference numerals:

1. a substrate; 2. a fracture mimic; 3. a holder cylinder; 4. an inlet end fitting; 5. an outlet end fitting; 6. a fluid injection channel; 7. a fluid production channel; 8. a nuclear magnetic resonance apparatus.

Detailed Description

The invention will be described in more detail below with reference to the accompanying drawings. While the preferred embodiments of the present invention are shown in the drawings, it should be understood that the present invention may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

According to an embodiment of the invention, a fractured tight reservoir physical model is provided, which is characterized by comprising: a substrate; the crack simulator is uniformly wrapped on the outer side of the substrate.

In one example, the permeability of the simulated fracture is adjusted by adjusting the particle size of the fracture mimic.

In one example, the matrix is a natural core.

In one example, the fracture analog is quartz sand.

FIG. 1 shows a schematic of a fractured tight reservoir physical model according to one embodiment of the invention.

FIG. 2 illustrates an A-A' directional cross-sectional view of a physical model of a fractured tight reservoir according to one embodiment of the invention.

FIG. 3 shows a B-B' directional cross-sectional view of a physical model of a fractured tight reservoir according to an embodiment of the invention.

Specifically, the fractured tight reservoir physical model is a cylinder, and comprises: the matrix 1 is a natural rock core; the crack simulator 2 is made of quartz sand and evenly wraps the outer side of the substrate 1, and the permeability of the simulated crack is adjusted by adjusting the granularity of the crack simulator 2.

According to an embodiment of the present invention, there is provided a recovery factor calculation system, characterized in that the system comprises: the holder cylinder is used for placing a physical model of the fractured compact reservoir; the connectors are detachably connected with the holder cylinder, and a through hole is formed in each connector along the radial direction of the holder cylinder; the fluid channels are respectively communicated with the inside of the holder cylinder body through holes, and the outer diameter of each fluid channel is equal to the inner diameter of each through hole; the nuclear magnetic resonance spectrometer probe is arranged on the outer periphery of the holder cylinder.

In one example, the outside diameter of the nipple is equal to the inside diameter of the gripper cylinder.

Specifically, according to an embodiment of the present invention, there is provided a recovery factor calculation system including: the holder cylinder is used for placing a physical model of the fractured compact reservoir; the connectors are detachably connected to the holder barrel, the outer diameter of each connector is equal to the inner diameter of the holder barrel, and a through hole is formed in each connector along the radial direction of the holder barrel; the fluid channels are respectively communicated with the interior of the cylinder body of the clamp holder through holes, and the outer diameter of each fluid channel is equal to the inner diameter of each through hole and is used for injecting a displacement medium into the cylinder body; the nuclear magnetic resonance instrument probe is arranged on the outer periphery of the holder cylinder and is used for monitoring a nuclear magnetic resonance T2 spectrum signal in the model.

It will be appreciated by persons skilled in the art that the above description of embodiments of the invention is intended only to illustrate the benefits of embodiments of the invention and is not intended to limit embodiments of the invention to any examples given.

Fig. 4 shows a flow chart of the steps of the method of oil recovery calculation according to the invention.

In this embodiment, the method of calculating a recovery factor according to the present invention may comprise: step 101, loading a physical model of a fractured compact reservoir into a holder cylinder; step 102, vacuumizing a physical model of the fractured compact oil reservoir, and further performing saturated oil treatment; 103, injecting a displacement medium into the fractured compact reservoir physical model treated by the saturated oil at a constant speed; and 104, monitoring nuclear magnetic resonance T2 spectrum signals in the model by a nuclear magnetic resonance instrument while injecting the displacement medium, and calculating the recovery factor.

In one example, loading the fractured tight reservoir physical model into the holder cylinder comprises: fixing a substrate on a joint at one end of the holder cylinder, wherein the central axis of the substrate is superposed with the central axis of the holder cylinder; filling a crack simulator into the holder cylinder containing the substrate, so that the crack simulator is filled with the substrate and the cavity of the holder cylinder; and closing and compacting the other end joint of the holder cylinder.

In one example, the recovery factor is calculated by equation (1):

wherein F is the recovery factor, A₀Is the area of the peak of the NMR signal at the initial time, A_iThe peak area of the NMR signal at time i.

In one example, further comprising: respectively scanning the matrix and the fractured compact reservoir physical model through a nuclear magnetic resonance instrument to respectively obtain nuclear magnetic resonance T2 spectrum signals of the matrix and the fractured compact reservoir physical model; distinguishing the matrix and the fracture analogue body by comparing nuclear magnetic resonance T2 spectrum signals, and further respectively determining the nuclear magnetic resonance T2 relaxation time ranges of the matrix and the fracture analogue body; and determining nuclear magnetic resonance T2 spectrum signals of the matrix and the fracture simulation body in the physical model of the fractured compact reservoir under different injection times according to the relaxation time range of the nuclear magnetic resonance T2, and further respectively calculating the recovery ratio of the matrix and the fracture simulation body.

In one example, the recovery factor of a substrate is calculated from the nuclear magnetic resonance T2 spectrum of the substrate by equation (2):

calculating the recovery ratio of the fracture simulation body according to the nuclear magnetic resonance T2 spectrum of the fracture simulation body by the formula (3):

wherein, F_SubstrateFor the recovery of the base fraction of crude oil, A_{0, matrix}The peak area of the nuclear magnetic resonance signal of the substrate portion at the initial time, A_{i, substrate}The peak area of the nuclear magnetic resonance signal of the substrate part at time i, F_{Crack simulator}Recovery of crude oil for the fracture analogue part, A_{0, crack simulator}The peak area of the nuclear magnetic resonance signal of the fracture analogue part at the initial time A_{i, crack simulator}The peak area of the nuclear magnetic resonance signal of the body part is simulated for the crack at time i.

Specifically, the method for calculating the recovery factor according to the present invention may include:

loading a physical model of the fractured tight reservoir into a holder cylinder, comprising:

the matrix is fixed on a joint at one end of the holder cylinder by a small amount of glue, the central axis of the matrix is superposed with the central axis of the holder cylinder, and the side surface of the core matrix can form a uniform space, so that quartz sand filling for simulating fracture cracks at the later stage is facilitated, and the simulated fracture cracks formed by filling the quartz sand can be uniform;

filling a crack simulator, namely quartz sand, in a holder cylinder containing a substrate, so that the substrate and a cavity of the holder cylinder are filled with the quartz sand, the mesh number of the quartz sand is selected according to the permeability of the simulated fracture, the holder cylinder is vertically placed in the filling process, and the quartz sand is slightly vibrated, so that all the quartz sand can be filled in the cavity formed by the substrate and the holder cylinder and can be in close contact with the cavity, and the permeability of the fractured fracture can be accurately simulated;

the cylinder body of the holder is vertically placed, and the other end connector is sealed and compacted, so that the whole physical model structure of the fractured compact oil reservoir containing the fracturing cracks is fixed, the subsequent experimental process is kept unchanged, and the matrix core is ensured to be formed to be located in the middle of the model, on the side face of the model and at the two ends of the model and contain the fracturing cracks.

And (3) vacuumizing the physical model of the fractured compact oil reservoir by using a molecular vacuum pump, and further injecting crude oil from the fluid channel to perform saturated oil treatment.

Injecting a displacement medium into the fractured compact oil reservoir physical model treated by saturated oil at a constant speed, and if the injected medium is water, preparing a saturated manganese chloride solution to ensure that the injected water has no nuclear magnetic resonance signal; if the injection medium is a gas, it is ensured that the injected gas composition is free of hydrogen, e.g. CO₂And N₂Isogas, which has no nuclear magnetic resonance signal.

The NMR T2 spectrum signal in the model was monitored by NMR while injecting displacement medium due to injection of water (saturated manganese chloride solution) or CO₂、N₂Without nuclear magnetic resonance signal, soThe nuclear magnetic resonance T2 spectrum signal of the model represents the simulated crude oil amount, and the recovery factor is calculated by the formula (1).

In order to better analyze the utilization of injected media to the crude oil in the fracture simulator and the matrix, the recovery ratio of the crude oil in the fracture simulator and the matrix is respectively calculated:

respectively scanning the matrix and the fractured compact reservoir physical model through a nuclear magnetic resonance instrument to respectively obtain nuclear magnetic resonance T2 spectrum signals of the matrix and the fractured compact reservoir physical model; and distinguishing the matrix and the fracture analogue body by comparing nuclear magnetic resonance T2 spectrum signals, and further respectively determining the nuclear magnetic resonance T2 relaxation time ranges of the matrix and the fracture analogue body.

And continuously carrying out nuclear magnetic resonance T2 spectrum test on the model while injecting the displacement medium, respectively determining nuclear magnetic resonance T2 spectrum signals of the matrix and the fracture simulation body in the physical model of the fractured tight oil reservoir under different injection times according to the relaxation time range of the nuclear magnetic resonance T2, calculating the recovery ratio of the matrix according to the nuclear magnetic resonance T2 spectrum of the matrix by a formula (2), and calculating the recovery ratio of the fracture simulation body according to the nuclear magnetic resonance T2 spectrum of the fracture simulation body by a formula (3).

The method comprises the steps of establishing a physical model of a fractured compact reservoir, developing a flow experiment of crude oil in the presence of fractures and matrixes, obtaining flow characteristics of the crude oil in the fractured fractures and the matrixes, respectively calculating the recovery ratio of the fractures and the matrixes, and evaluating the oil displacement effect of different displacement media in the presence of the fractured fractures and the matrixes.

To facilitate understanding of the aspects of the embodiments of the present invention and their effects, two specific application examples are given below. It will be understood by those skilled in the art that this example is merely for the purpose of facilitating an understanding of the present invention and that any specific details thereof are not intended to limit the invention in any way.

Application example 1

The permeability of matrix core is 0.3mD, the core size is 2.5cm in diameter and 5cm in length.

FIG. 5 shows a schematic of a recovery factor calculation system according to one embodiment of the present invention.

Fixing a natural rock core on an outlet end joint 5 of a holder cylinder 3 by using a small amount of glue, filling 100-mesh quartz sand into the holder cylinder 3 containing the natural rock core, so that the quartz sand is filled in a cavity formed by the natural rock core and the holder cylinder 3, vertically placing the holder cylinder 3 in the filling process, slightly vibrating to ensure that all the quartz sand can be filled in the cavity formed by the natural rock core and the holder cylinder 3 and can be in close contact with each other, and the permeability of a simulated fracturing fracture is 2D. The holder cylinder 3 is vertically placed, and the inlet end joint 4 is sealed and compacted, so that the whole physical model structure of the fractured compact oil reservoir containing the fracturing cracks is fixed, the subsequent experimental process is kept unchanged, and the natural rock core is ensured to be formed to be located in the middle of the model, on the side surface of the model and at the two ends of the model and contain the fracturing cracks. The length of the formed physical model of the fractured compact reservoir is 5.4cm, and the diameter of the physical model of the fractured compact reservoir is 2.9 cm.

Vacuumizing the physical model of the fractured compact oil reservoir by using a molecular vacuum pump to ensure that the vacuum degree reaches 10^-9mPa, and continuously vacuumizing for 24 hours; further, crude oil was injected from the fluid injection channel 6, flowed out from the fluid production channel 7, and gradually increased in pressure to the experimental pressure of 10MPa, and saturated for 72 hours.

Figure 6 shows a schematic representation of a final nuclear magnetic resonance T2 spectrogram according to an embodiment of the present invention.

CO injection at a constant rate of 0.2ml/min₂Displacing the crude oil within the model. Under the experimental pressure condition, CO is injected at a constant speed by using a pump₂. In the injection of CO₂Meanwhile, a nuclear magnetic resonance T2 spectrum test is continuously carried out on the model through the nuclear magnetic resonance instrument 8 until the nuclear magnetic resonance T2 spectrum of the model is not changed, the displacement experiment is finished, the final nuclear magnetic resonance T2 spectrum is shown in figure 6, and the recovery ratio of the crude oil is calculated to be 31.17% through the formula (1).

Application example 2

The fracture simulation and the recovery of crude oil in the matrix were further calculated on the basis of application example 1.

Fig. 7 shows a schematic diagram of a nuclear magnetic resonance T2 spectrum of a physical model of a natural core and fractured tight reservoir according to an embodiment of the invention.

Respectively scanning the physical models of the natural rock core and the fractured compact reservoir by using a nuclear magnetic resonance instrument 8, and comparing nuclear magnetic resonance T2 spectrum signals of the natural rock core and the fractured compact reservoir to distinguish the natural rock core from the quartz sand, wherein the relaxation time corresponding to a black vertical line in the graph is determined to be a relaxation time division line of the natural rock core and the quartz sand, and further the nuclear magnetic resonance T2 relaxation time ranges of the natural rock core and the fractured are respectively determined: the T2 relaxation time of the natural core is 0.1-86ms, and the T2 relaxation time of the quartz sand is greater than 86 ms.

Fig. 8 shows a schematic diagram of a nuclear magnetic resonance T2 spectrum of a natural core and quartz sand in a physical model of a fractured tight reservoir according to an embodiment of the invention.

In CO₂And continuously carrying out nuclear magnetic resonance T2 spectrum test on the model while injecting, determining nuclear magnetic resonance T2 spectrum signals of the physical model of the fractured compact reservoir at different injection times, and distinguishing the nuclear magnetic resonance T2 spectrum of the natural rock core and the quartz sand as shown in figure 8, wherein the region with the relaxation time of 0.1-86ms is the nuclear magnetic resonance T2 spectrum corresponding to the natural rock core, and the region with the relaxation time of more than 86ms is the nuclear magnetic resonance T2 spectrum corresponding to the quartz sand. According to the nuclear magnetic resonance T2 spectrums of the natural rock core and the quartz sand, the recovery ratio of the natural rock core is calculated to be 27.63% by the formula (2), and the recovery ratio of the quartz sand is calculated to be 93.16% by the formula (3).

In conclusion, the invention obtains the flow characteristics of the crude oil in the fractured fractures and the matrix by establishing a fractured compact reservoir physical model and developing the flow experiment of the crude oil in the presence of the fractures and the matrix, respectively calculates the recovery ratio of the fractures and the matrix, and evaluates the oil displacement effect of different displacement media in the presence of the fractured fractures and the matrix.

It will be appreciated by persons skilled in the art that the above description of embodiments of the invention is intended only to illustrate the benefits of embodiments of the invention and is not intended to limit embodiments of the invention to any examples given.

Having described embodiments of the present invention, the foregoing description is intended to be exemplary, not exhaustive, and not limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.