CN107101773B - Method and device for testing bubble point pressure value and quasi-bubble point pressure value - Google Patents
Method and device for testing bubble point pressure value and quasi-bubble point pressure value Download PDFInfo
- Publication number
- CN107101773B CN107101773B CN201710242780.4A CN201710242780A CN107101773B CN 107101773 B CN107101773 B CN 107101773B CN 201710242780 A CN201710242780 A CN 201710242780A CN 107101773 B CN107101773 B CN 107101773B
- Authority
- CN
- China
- Prior art keywords
- pressure value
- scanning image
- value
- porous medium
- image
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 44
- 238000012360 testing method Methods 0.000 title claims abstract description 35
- 238000002591 computed tomography Methods 0.000 claims abstract description 308
- 239000006260 foam Substances 0.000 claims abstract description 80
- 238000001035 drying Methods 0.000 claims abstract description 5
- 238000005259 measurement Methods 0.000 claims description 35
- 239000004576 sand Substances 0.000 claims description 27
- 238000004088 simulation Methods 0.000 claims description 7
- 239000003921 oil Substances 0.000 description 111
- 238000010586 diagram Methods 0.000 description 11
- 239000007789 gas Substances 0.000 description 7
- 230000015572 biosynthetic process Effects 0.000 description 4
- 239000000295 fuel oil Substances 0.000 description 4
- 238000011084 recovery Methods 0.000 description 4
- 238000009792 diffusion process Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 239000003345 natural gas Substances 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 239000003209 petroleum derivative Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 238000012800 visualization Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L11/00—Measuring steady or quasi-steady pressure of a fluid or a fluent solid material by means not provided for in group G01L7/00 or G01L9/00
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N23/00—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
- G01N23/02—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material
- G01N23/04—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material and forming images of the material
- G01N23/046—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material and forming images of the material using tomography, e.g. computed tomography [CT]
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Engineering & Computer Science (AREA)
- Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
- Pulmonology (AREA)
- Radiology & Medical Imaging (AREA)
- Theoretical Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Analysing Materials By The Use Of Radiation (AREA)
Abstract
The embodiment of the application discloses a method and a device for testing a bubble point pressure value and a simulated bubble point pressure value. The bubble point pressure value testing method comprises the following steps: after drying and loading a porous medium sample into a measuring container, acquiring a first CT scanning image of the porous medium sample; injecting foam oil into the measuring container to enable the pressure value in the measuring container to be a first preset value, and acquiring a second CT scanning image of the porous medium sample; gradually reducing the pressure value in the measuring container until the pressure value in the measuring container is a second preset value; and acquiring at least one third CT scan image of the porous medium sample during the gradual reduction of pressure values; determining a bubble point pressure value of the foam oil in the porous medium sample based on the first CT scan image, the second CT scan image, and the at least one third CT scan image.
Description
Technical Field
The application relates to the technical field of petroleum and natural gas, in particular to a method and a device for testing a bubble point pressure value and a quasi-bubble point pressure value.
Background
The thickened oil resources in China, Canada, Venezuela and other areas are very rich. The produced oil of part of heavy oil reservoirs in the process of exploitation is in a continuous foam state, and a large number of stable small bubbles are contained in the produced oil. The oil produced is referred to as foam oil. The mass production practice shows that the recovery ratio of the heavy oil reservoir is 5-25% higher than that of the conventional dissolved gas flooding reservoir, the oil recovery speed is 10-30 times higher, and some oil recovery speed is even up to 100 times higher due to the foam oil phenomenon. Therefore, the research on the mechanism of the foam oil is very important for improving the recovery ratio of the heavy oil reservoir.
Porous media are widely present in heavy oil reservoirs. Such as sandstone, mudstone, etc. Therefore, in the process of researching the mechanism of the foam oil, the bubble point pressure value and the quasi-bubble point pressure value of the foam oil in the porous medium are important parameters to be mastered.
In the prior art, a PVT instrument is usually adopted to directly test a bubble point pressure value and a pseudo-bubble point pressure value of foam oil, the measured bubble point pressure value is taken as a bubble point pressure value of the foam oil in a porous medium, and the measured pseudo-bubble point pressure value is taken as a pseudo-bubble point pressure value of the foam oil in the porous medium. However, the above prior art testing process does not involve the presence of a porous medium. Generally, the force between oil and gas molecules is different from the force between porous medium molecules. Therefore, the bubble point pressure value obtained by the test of the prior art cannot truly reflect the bubble point pressure value of the foam oil in the porous medium. Similarly, the bubble point pressure value obtained by the above prior art test cannot truly reflect the bubble point pressure value of the foam oil in the porous medium. At present, a method for accurately testing the bubble point pressure value and the quasi-bubble point pressure value of the foam oil in the porous medium is urgently needed.
Disclosure of Invention
The embodiment of the application aims to provide a method and a device for testing a bubble point pressure value and a simulated bubble point pressure value, so as to accurately test the bubble point pressure value and the simulated bubble point pressure value of foam oil in a porous medium.
In order to achieve the above object, an embodiment of the present application provides a method for testing a bubble point pressure value, including: after drying and loading a porous medium sample into a measuring container, acquiring a first CT scanning image of the porous medium sample; injecting foam oil into the measuring container to enable the pressure value in the measuring container to be a first preset value, and acquiring a second CT scanning image of the porous medium sample; gradually reducing the pressure value in the measuring container until the pressure value in the measuring container is a second preset value; and acquiring at least one third CT scan image of the porous medium sample during the gradual reduction of pressure values; determining a bubble point pressure value of the foam oil in the porous medium sample based on the first CT scan image, the second CT scan image, and the at least one third CT scan image.
In order to achieve the above object, an embodiment of the present application provides a method for testing a pseudo bubble point pressure value, including: after drying and loading a porous medium sample into a measuring container, acquiring a first CT scanning image of the porous medium sample; injecting foam oil into the measuring container to enable the pressure value in the measuring container to be a first preset value, and acquiring a second CT scanning image of the porous medium sample; gradually reducing the pressure value in the measuring container until the pressure value in the measuring container is a second preset value; and acquiring at least one third CT scan image of the porous medium sample during the gradual reduction of pressure values; and determining a quasi-bubble point pressure value of the foam oil in the porous medium sample based on the first CT scanning image, the second CT scanning image and the at least one third CT scanning image.
In order to achieve the above object, an embodiment of the present application provides a bubble point pressure value testing apparatus, including: the device comprises a first CT scanning image acquisition unit, a second CT scanning image acquisition unit and a measurement container, wherein the first CT scanning image acquisition unit is used for acquiring a first CT scanning image of a porous medium sample through CT scanning after the porous medium sample is dried and loaded into the measurement container; the second CT scanning image acquisition unit is used for injecting foam oil into the measuring container to enable the pressure value in the measuring container to be a first preset value; obtaining a second CT scanning image of the porous medium sample through CT scanning; the third CT scanning image acquisition unit is used for gradually reducing the pressure value in the measuring container until the pressure value in the measuring container is a second preset value; and obtaining at least one third CT scan image of the porous medium sample by CT scan during the process of reducing the pressure value; and the bubble point pressure value determining unit is used for determining the bubble point pressure value of the foam oil in the porous medium sample based on the first CT scanning image, the second CT scanning image and the at least one third CT scanning image.
In order to achieve the above object, an embodiment of the present application provides a device for testing a pseudo bubble point pressure value, including: the device comprises a first CT scanning image acquisition unit, a second CT scanning image acquisition unit and a measurement container, wherein the first CT scanning image acquisition unit is used for acquiring a first CT scanning image of a porous medium sample through CT scanning after the porous medium sample is dried and loaded into the measurement container; the second CT scanning image acquisition unit is used for injecting foam oil into the measuring container to enable the pressure value in the measuring container to be a first preset value; obtaining a second CT scanning image of the porous medium sample through CT scanning; the third CT scanning image acquisition unit is used for gradually reducing the pressure value in the measuring container until the pressure value in the measuring container is a second preset value; and obtaining at least one third CT scan image of the porous medium sample by CT scan during the process of reducing the pressure value; and the bubble point simulation pressure value determining unit is used for determining the bubble point simulation pressure value of the foam oil in the porous medium sample based on the first CT scanning image, the second CT scanning image and the at least one third CT scanning image.
According to the technical scheme provided by the embodiment of the application, the bubble point pressure value and the quasi-bubble point pressure value of the foam oil in the porous medium sample can be tested through the CT scanning image of the porous medium sample. Compared with the prior art, the embodiment of the application has the participation of the porous medium in the test process, so that the bubble point pressure value and the quasi-bubble point pressure value of the foam oil in the porous medium can be accurately obtained.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, it is obvious that the drawings in the following description are only some embodiments described in the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without any creative effort.
Fig. 1 is a flowchart of a bubble point pressure value testing method according to an embodiment of the present application;
fig. 2 is a flowchart of a method for testing a bubble point pressure value in an embodiment of the present application;
FIG. 3 is a schematic diagram illustrating an oil saturation frequency distribution curve of a CT scan according to an embodiment of the present disclosure;
FIG. 4a is a schematic view of a CT scan according to an embodiment of the present application;
FIG. 4b is a schematic view of another CT scan according to an embodiment of the present application;
FIG. 4c is a schematic view of another CT scan according to an embodiment of the present application;
FIG. 4d is a schematic view of another CT scan according to an embodiment of the present application;
FIG. 4e is a schematic view of another CT scan according to an embodiment of the present application;
FIG. 4f is a schematic view of another CT scan according to an embodiment of the present application;
FIG. 4g is a schematic view of another CT scan according to an embodiment of the present application;
FIG. 4h is a schematic view of another CT scan according to an embodiment of the present application;
fig. 5 is a schematic functional structure diagram of a bubble point pressure value testing device according to an embodiment of the present application;
fig. 6 is a functional structure diagram of a device for testing a bubble point pressure value according to an embodiment of the present application.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
During the dissolved gas flooding production process, the mobility and compressibility of the thick oil are increased, which is the reason that the thick oil is in a foam state. The minimum formation pressure value at which the thick oil assumes a continuous foam state is generally taken as the bubble point pressure value. And when the formation pressure value is less than the bubble point pressure value, the dissolved gas in the thick oil is separated out in the form of diffusion gas to form a freely moving gas phase until the formation pressure value is lower. In this way, the formation pressure value at which the diffusion gas stops being precipitated is generally set as the pseudo bubble point pressure value.
CT (Computed Tomography) scanning is taken as a nondestructive visualization technology and can be applied to the test of the bubble point pressure value and the quasi-bubble point pressure value of the foam oil in the porous medium. Please refer to fig. 1. The embodiment of the application provides a method for testing a bubble point pressure value. The method comprises the following steps.
Step S11: after the porous media sample is dried and loaded into a measurement vessel, a first CT scan image of the porous media sample is acquired.
In this embodiment, the porous medium sample may be a sandstone sample, a mudstone sample, a sand-packed model sample, or the like. The measurement receptacle may be a core holder. Of course, the measuring container may be any other container. Such as a sand pack.
In this embodiment, the porous media sample may be dried and loaded into the measurement receptacle by a tester. Of course, the porous medium sample may be dried by another body and loaded into the measuring vessel. Such as a computer, etc.
In this embodiment, the porous medium sample may be scanned by using a CT apparatus to obtain a scanned image of the porous medium sample, and the obtained scanned image may be used as the first CT scanned image. Including but not limited to medical CT instruments and the like.
Step S12: and injecting foam oil into the measuring container to enable the pressure value in the measuring container to be a first preset value, and acquiring a second CT scanning image of the porous medium sample.
In this embodiment, the first preset value is generally greater than or equal to the bubble point pressure value of the foam oil in the porous medium sample, and may be any real number. For example, the porous medium sample may be a sandstone sample, and the first preset value may be 7 MPa. The first preset value may be an empirical value. Of course, the first preset value can also be obtained by testing through other methods.
In this embodiment, the size of the second CT scan image may be the same as the size of the first CT scan image. For example, the second CT scan image and the first CT scan image may each have a size of 512 pixels by 512 pixels.
In this embodiment, the foam oil may be injected into the measurement container by an injection pump until the pressure value of the foam oil in the measurement container is a first preset value. As such, the porous media sample may be saturated with foam oil. Optionally, the measuring container can be vacuumized, so that the porous medium sample is in a vacuum state; and injecting foam oil into the measuring container after vacuumizing.
In this embodiment, the second CT scan image may be acquired in a manner similar to the manner in which the first CT scan image is acquired. The two can be explained in comparison, and are not described in detail herein.
Step S13: gradually reducing the pressure value in the measuring container until the pressure value in the measuring container is a second preset value; and acquiring at least one third CT scan image of the porous medium sample during the step of reducing the pressure value.
In this embodiment, the second preset value is generally smaller than or equal to the pseudo-bubble point pressure value of the foam oil in the porous medium sample, and may be any real number. For example, it may be 0 MPa. The second preset value may be an empirical value. Of course, the second preset value can also be obtained by testing through other methods. The third CT scan image may be the same size as the first CT scan image.
In this embodiment, the following sub-steps may be specifically adopted to obtain at least one third CT scan image of the porous medium sample.
Step a: and reducing the pressure value in the measuring container by a specified value, and acquiring a third CT scanning image of the porous medium sample.
In this embodiment, the specified value can be flexibly set according to actual needs. For example, it may be 0.2 MPa.
In this embodiment, the pressure value in the measuring vessel can be lowered by a specified value by controlling a valve; and after the pressure of the foam oil in the measuring container is balanced, a third CT scanning image of the porous medium sample can be obtained. The third CT scan image may be acquired in a manner similar to the manner in which the first CT scan image is acquired. The two can be explained in comparison, and are not described in detail herein.
Step b: and c, repeating the step a until the pressure value in the measuring container is a second preset value.
In this embodiment, step a is repeated until the pressure value in the measuring container is a second preset value. In this manner, one or more third CT scan images may be obtained.
Step S14: determining a bubble point pressure value of the foam oil in the porous medium sample based on the first CT scan image, the second CT scan image, and the at least one third CT scan image.
In this embodiment, as mentioned above, the first CT scan image, the second CT scan image, and the at least one third CT scan image may have the same size. In this way, for each of the at least one third CT scan image, the CT value of each pixel point in the first CT scan image, the CT value of each pixel point in the second CT scan image, and the third CT scan image may be based onAnd calculating the oil saturation value of each pixel point in the third CT scanning image according to the CT value of each pixel point in the image. In particular, a formula may be employedAnd calculating the oil saturation value of each pixel point in the third CT scanning image. Wherein S iso,iThe oil saturation value S of the pixel point i in the third CT scanning imageo；CTx,iThe CT value of the pixel point i in the third CT scanning image is obtained; CTdry,iThe CT value of a pixel point i in the first CT scanning image is obtained; CTwet,iAnd the CT value of the pixel point i in the second CT scanning image is obtained.
In this way, the bubble point pressure value of the foam oil in the porous medium sample can be determined based on the oil saturation values of the respective pixel points in each of the at least one third CT scan image. Specifically, for each third CT scan image in the at least one third CT scan image, the oil saturation distribution rate of the third CT scan image may be obtained based on the oil saturation values of each pixel point in the third CT scan image; the bubble point pressure value of the foam oil in the porous medium sample can be determined based on the oil saturation distribution rate of each of the at least one third CT scan image.
For example, for each third CT scan image in the at least one third CT scan image, the oil saturation value of each pixel point in the third CT scan image may be obtained, and the number of pixel points corresponding to each oil saturation value may be counted; the oil saturation frequency distribution curve of the CT scanning image can be drawn based on the number of the pixel points corresponding to each oil saturation value. Then, at least one oil saturation frequency distribution curve which does not have monotonicity in a defined interval can be selected from the oil saturation frequency distribution curves of the at least one third CT scanning image; a set of third CT scan images corresponding to the at least one oil saturation frequency distribution curve may be used as the third CT scan image set.
As previously described, a third CT scan image of the porous medium sample may be obtained after each drop in pressure value within the measurement vessel by a specified value. Thus, each third CT scan image may correspond to a measured vessel pressure value. Then, a third CT scan image with the maximum pressure value corresponding to the measurement container may be selected from the third CT scan image set as a first target third CT scan image; the pressure value of the measurement container corresponding to the first target third CT scan image may be used as the bubble point pressure value of the foam oil in the porous medium sample.
According to the embodiment of the application, the bubble point pressure value of the foam oil in the porous medium sample can be tested through the CT scanning image of the porous medium sample. Compared with the prior art, the embodiment of the application has the participation of the porous medium in the test process, so that the bubble point pressure value of the foam oil in the porous medium can be accurately tested.
Please refer to fig. 2. The embodiment of the application also provides a method for testing the bubble point simulation pressure value. The method comprises the following steps.
Step S21: after the porous media sample is dried and loaded into a measurement vessel, a first CT scan image of the porous media sample is acquired.
Step S22: and injecting foam oil into the measuring container to enable the pressure value in the measuring container to be a first preset value, and acquiring a second CT scanning image of the porous medium sample.
Step S23: gradually reducing the pressure value in the measuring container until the pressure value in the measuring container is a second preset value; and acquiring at least one third CT scan image of the porous medium sample during the step of reducing the pressure value.
Step S24: and determining a quasi-bubble point pressure value of the foam oil in the porous medium sample based on the first CT scanning image, the second CT scanning image and the at least one third CT scanning image.
In this embodiment, the first CT scan image, the second CT scan image, and the at least one third CT scan image may have the same size. Thus, for each third CT scan image in the at least one third CT scan image, the oil saturation value of each pixel point in the third CT scan image may be calculated based on the CT value of each pixel point in the first CT scan image, the CT value of each pixel point in the second CT scan image, and the CT value of each pixel point in the third CT scan image. The specific calculation process may refer to step S14 of the foregoing embodiment.
In this way, the bubble point simulation pressure value of the foam oil in the porous medium sample can be determined based on the oil saturation values of the pixel points in each of the at least one third CT scan image. Specifically, for each third CT scan image in the at least one third CT scan image, the oil saturation distribution rate of the third CT scan image may be obtained based on the oil saturation values of each pixel point in the third CT scan image; the bubble point pressure value of the foam oil in the porous medium sample can be determined based on the oil saturation degree distribution rate of each of the at least one third CT scan image.
For example, for each third CT scan image in the at least one third CT scan image, the oil saturation value of each pixel point in the third CT scan image may be obtained, and the number of pixel points corresponding to each oil saturation value may be counted; the oil saturation frequency distribution curve of the CT scanning image can be drawn based on the number of the pixel points corresponding to each oil saturation value. Then, at least one oil saturation frequency distribution curve which does not have monotonicity in a defined interval can be selected from the oil saturation frequency distribution curves of the at least one third CT scanning image; the third CT scan image corresponding to the at least one oil saturation frequency distribution curve may be used as the third CT scan image set.
As previously described, a third CT scan image of the porous medium sample may be obtained after each drop in pressure value within the measurement vessel by a specified value. Thus, each third CT scan image may correspond to a measured vessel pressure value. Then, a third CT scan image with the maximum pressure value corresponding to the measurement container may be selected from the third CT scan image set as a first target third CT scan image; the oil saturation frequency distribution curve of the first target third CT scan image may be used as a reference oil saturation frequency distribution curve; the pressure value of the measurement container corresponding to the first target third CT scan image can be used as a reference pressure value; a sub-third CT scan image set, in which the corresponding pressure value of the measurement container is smaller than the reference pressure value and the number of extreme points of the oil saturation curve is different from the reference oil saturation frequency distribution curve, may be selected from the third CT scan image set, and the number of the third CT scan images in the sub-third CT scan image set may be one or more; a third CT scanning image with the maximum oil saturation value corresponding to the peak value of the oil saturation frequency distribution curve can be selected from the sub-third CT scanning image set and used as a second target third CT scanning image; the oil saturation distribution value of the second target third CT scan image may be used as the pseudo-bubble point pressure value of the foam oil in the porous medium sample.
According to the embodiment of the application, the quasi-bubble point pressure value of the foam oil in the porous medium sample can be tested through the CT scanning image of the porous medium sample. Compared with the prior art, the embodiment of the application has the participation of the porous medium in the test process, so that the bubble point simulation pressure value of the foam oil in the porous medium can be accurately tested.
A specific application scenario of the method for testing the bubble point pressure value and the quasi-bubble point pressure value in the embodiment of the application is described below. In the application scenario, the porous medium sample may be a sand-packed model sample. The porosity of the sand pack model sample may be 36.5% and the air permeability may be 5541 mD. The viscosity of the foam oil can be 6151 cp. The first preset value may be 7 MPa. The second preset value may be 3 MPa. The specified value may be 0.2 MPa.
In this manner, after the sand-packed model sample is dried and loaded into a sand-packed tube, a first CT scan image of the sand-packed model sample may be acquired. Foam oil can be injected into the sand filling pipe, so that the pressure value in the sand filling pipe is 7MPa, and a second CT scanning image of the sand filling model sample can be obtained. The pressure value in the sand-packed pipe can be gradually reduced until the pressure value in the sand-packed pipe is 3 MPa. Specifically, the pressure of the foam oil in the sand-filled pipe can be reduced by 0.2MPa each time, and after the pressure of the foam oil in the sand-filled pipe is balanced, a third CT scan image of the sand-filled model sample is obtained. Thus, 20 third CT scan images can be obtained. The bubble point pressure value and the pseudo-bubble point pressure value of the foam oil in the porous medium sample can be determined based on the first CT scan image, the second CT scan image and the 20 third CT scan images.
For example, fig. 3 is a schematic view of the oil saturation frequency distribution curve corresponding to each third CT scan image when the pressure values in the sand pack pipe are 6.8MPa, 6.0MPa, 5.6MPa, 5.2MPa, 4.4MPa, 4MPa, 3.6MPa, and 3MPa, respectively. The abscissa of the oil saturation frequency distribution curve is an oil saturation value, and the ordinate is the percentage of the number of pixels corresponding to the oil saturation value to the total number of pixels in the third CT scanning image. FIG. 4a is a schematic diagram of a third CT scan image corresponding to a pressure value of 6.8MPa in the sand-filled tube. FIG. 4b is a schematic diagram of a third CT scan image corresponding to a pressure value of 6.0MPa in the sand-filled pipe. FIG. 4c is a schematic diagram of a third CT scan image corresponding to a pressure value of 5.6MPa in the sand-filled pipe. FIG. 4d is a schematic diagram of a third CT scan image corresponding to a pressure value of 5.2MPa in the sand-filled pipe. Fig. 4e is a schematic diagram of the pressure value in the sand-filled pipe corresponding to the third CT scan image when the pressure value is 4.4 MPa. FIG. 4f is a schematic diagram of a third CT scan image corresponding to a pressure value of 4MPa in the sand-filled pipe. FIG. 4g is a schematic diagram of a third CT scan image corresponding to a pressure value of 3.6MPa in the sand-filled pipe. FIG. 4h is a schematic diagram of a third CT scan image corresponding to a pressure value of 3MPa in the sand-filled pipe.
As can be seen from fig. 3, when the pressure values in the sand-packed pipe are 5.6MPa, 5.2MPa, 4.4MPa, 4MPa, 3.6MPa, and 3MPa, respectively, the frequency distribution curves of the oil saturation corresponding to the respective third CT scan images do not have monotonicity within the defined interval. Then, 5.6MPa can be used as the bubble point pressure value of the foam oil in the sand pack model sample.
When the pressure value in the sand-filled pipe is 5.6MPa, the oil saturation frequency distribution curve corresponding to the third CT scanning image is used as a reference oil saturation frequency distribution curve; the pressure value of 5.6MPa can be taken as a reference pressure value; when the pressure values in the sand-filled pipe are respectively 5.6MPa, 5.2MPa, 4.4MPa, 4MPa, 3.6MPa and 3MPa, and corresponding third CT scanning images are selected from corresponding third CT scanning images, wherein the corresponding pressure value of the measuring container is smaller than the reference pressure value, and the number of the corresponding extreme points of the oil saturation curve is different from the reference oil saturation frequency distribution curve, so that the corresponding third CT scanning images are obtained when the pressure values in the sand-filled pipe are respectively 4.4MPa, 4MPa, 3.6MPa and 3 MPa. When the pressure values in the sand-filled pipe are respectively 4.4MPa, 4MPa, 3.6MPa and 3MPa, the oil saturation value corresponding to the peak value of the oil saturation frequency distribution curve corresponding to the third CT scan image is the largest (i.e., the peak value is rightmost) when the pressure value in the sand-filled pipe is 4MPa in each corresponding third CT scan image. Then, 4MPa can be used as the pseudo-bubble point pressure value of the foam oil in the porous medium sample.
Please refer to fig. 5. The embodiment of the application also provides a bubble point pressure testing device. The method comprises the following steps:
a first CT scan image obtaining unit 51, configured to obtain a first CT scan image of the porous medium sample through CT scan after the porous medium sample is dried and loaded into the measurement container;
a second CT scan image obtaining unit 52, configured to inject foam oil into the measurement container, so that a pressure value in the measurement container is a first preset value; obtaining a second CT scanning image of the porous medium sample through CT scanning;
a third CT scan image obtaining unit 53, configured to gradually reduce the pressure value in the measurement container until the pressure value in the measurement container is a second preset value; and obtaining at least one third CT scan image of the porous medium sample by CT scan during the process of reducing the pressure value;
a bubble point pressure value determining unit 54, configured to determine a bubble point pressure value of the foam oil in the porous medium sample based on the first CT scan image, the second CT scan image, and the at least one third CT scan image.
Please refer to fig. 6. The embodiment of the application also provides a bubble point pressure testing device. The method comprises the following steps:
a first CT scan image obtaining unit 51, configured to obtain a first CT scan image of the porous medium sample through CT scan after the porous medium sample is dried and loaded into the measurement container;
a second CT scan image obtaining unit 52, configured to inject foam oil into the measurement container, so that a pressure value in the measurement container is a first preset value; obtaining a second CT scanning image of the porous medium sample through CT scanning;
a third CT scan image obtaining unit 53, configured to gradually reduce the pressure value in the measurement container until the pressure value in the measurement container is a second preset value; and obtaining at least one third CT scan image of the porous medium sample by CT scan during the process of reducing the pressure value;
and the bubble point pressure value determining unit 61 is configured to determine a bubble point pressure value of the foam oil in the porous medium sample based on the first CT scan image, the second CT scan image, and the at least one third CT scan image.
While the present application has been described with examples, those of ordinary skill in the art will appreciate that there are numerous variations and permutations of the present application without departing from the spirit of the application, and it is intended that the appended claims encompass such variations and permutations without departing from the spirit of the application.
Claims (16)
1. A bubble point pressure value testing method is characterized by comprising the following steps:
after drying and loading a porous medium sample into a measuring container, acquiring a first CT scanning image of the porous medium sample;
injecting foam oil into the measuring container to enable the pressure value in the measuring container to be a first preset value, and acquiring a second CT scanning image of the porous medium sample;
gradually reducing the pressure value in the measuring container until the pressure value in the measuring container is a second preset value; and acquiring at least one third CT scan image of the porous medium sample during the gradual reduction of pressure values;
determining a bubble point pressure value of the foam oil in the porous medium sample based on the first CT scan image, the second CT scan image, and the at least one third CT scan image.
2. The method of claim 1, wherein said obtaining at least one third CT scan image of said porous medium sample comprises:
step a: reducing the pressure value in the measuring container by a specified value, and acquiring a third CT scanning image of the porous medium sample;
step b: and c, repeating the step a until the pressure value in the measuring container is a second preset value.
3. The method of claim 1, wherein the determining a bubble point pressure value of the foam oil in the porous medium comprises:
for each third CT scanned image in the at least one third CT scanned image, calculating an oil saturation value of each pixel point in the third CT scanned image based on the CT value of each pixel point in the first CT scanned image, the CT value of each pixel point in the second CT scanned image, and the CT value of each pixel point in the third CT scanned image;
and determining the bubble point pressure value of the foam oil in the porous medium sample based on the oil saturation value of each pixel point in each third CT scanning image in the at least one third CT scanning image.
4. The method of claim 3, wherein said calculating the oil saturation value of each pixel in the third CT scan comprises:
using a formulaCalculating the oil saturation value of each pixel point in the third CT scanning image; wherein,
So,ithe oil saturation value S of the pixel point i in the third CT scanning imageo；
CTx,iThe CT value of the pixel point i in the third CT scanning image is obtained;
CTdry,ithe CT value of a pixel point i in the first CT scanning image is obtained;
CTwet,iand the CT value of the pixel point i in the second CT scanning image is obtained.
5. The method of claim 3, wherein the determining a bubble point pressure value of the foam oil in the sample of porous media comprises:
for each third CT scanning image in the at least one third CT scanning image, acquiring the oil saturation distribution rate of the third CT scanning image based on the oil saturation values of all pixel points in the third CT scanning image;
and determining a bubble point pressure value of the foam oil in the porous medium sample based on the oil saturation distribution rate of each of the at least one third CT scanning image.
6. The method of claim 5, wherein the oil saturation distribution rate of the third CT scan image is represented by an oil saturation frequency distribution curve;
accordingly, the determining the bubble point pressure value of the foam oil in the porous medium sample comprises:
selecting at least one oil saturation frequency distribution curve which does not have monotonicity in a defined interval from the oil saturation frequency distribution curves of the at least one third CT scanning image; a set formed by third CT scanning images corresponding to the at least one oil saturation frequency distribution curve is used as a third CT scanning image set;
selecting a third CT scanning image with the maximum corresponding pressure value of the measuring container from the third CT scanning image set as a first target third CT scanning image; and taking the pressure value of the measurement container corresponding to the first target third CT scanning image as a reference pressure value and a bubble point pressure value of the foam oil in the porous medium sample.
7. The method of claim 1, wherein the porous medium sample is a sand pack model sample and the measurement container is a sand pack pipe or a core holder.
8. The utility model provides a bubble point pressure value testing arrangement which characterized in that includes:
the device comprises a first CT scanning image acquisition unit, a second CT scanning image acquisition unit and a measurement container, wherein the first CT scanning image acquisition unit is used for acquiring a first CT scanning image of a porous medium sample through CT scanning after the porous medium sample is dried and loaded into the measurement container;
the second CT scanning image acquisition unit is used for injecting foam oil into the measuring container to enable the pressure value in the measuring container to be a first preset value; obtaining a second CT scanning image of the porous medium sample through CT scanning;
the third CT scanning image acquisition unit is used for gradually reducing the pressure value in the measuring container until the pressure value in the measuring container is a second preset value; and obtaining at least one third CT scan image of the porous medium sample by CT scan in the process of reducing the pressure value;
and the bubble point pressure value determining unit is used for determining the bubble point pressure value of the foam oil in the porous medium sample based on the first CT scanning image, the second CT scanning image and the at least one third CT scanning image.
9. A method for testing a quasi-bubble point pressure value is characterized by comprising the following steps:
after drying and loading a porous medium sample into a measuring container, acquiring a first CT scanning image of the porous medium sample;
injecting foam oil into the measuring container to enable the pressure value in the measuring container to be a first preset value, and acquiring a second CT scanning image of the porous medium sample;
gradually reducing the pressure value in the measuring container until the pressure value in the measuring container is a second preset value; and acquiring at least one third CT scan image of the porous medium sample during the gradual reduction of pressure values;
and determining a quasi-bubble point pressure value of the foam oil in the porous medium sample based on the first CT scanning image, the second CT scanning image and the at least one third CT scanning image.
10. The method of claim 9, wherein said obtaining at least one third CT scan image of said porous medium sample comprises:
step a: reducing the pressure value in the measuring container by a specified value, and acquiring a third CT scanning image of the porous medium sample;
step b: and c, repeating the step a until the pressure value in the measuring container is a second preset value.
11. The method of claim 9, wherein the determining the bubble point pressure value of the foam oil in the porous medium comprises:
for each third CT scanned image in the at least one third CT scanned image, calculating an oil saturation value of each pixel point in the third CT scanned image based on the CT value of each pixel point in the first CT scanned image, the CT value of each pixel point in the second CT scanned image, and the CT value of each pixel point in the third CT scanned image;
and determining the quasi-bubble point pressure value of the foam oil in the porous medium sample based on the oil saturation values of all pixel points in each third CT scanning image in the at least one third CT scanning image.
12. The method of claim 11, wherein said calculating the oil saturation value of each pixel in the third CT scan image comprises:
using a formulaCalculating the oil saturation value of each pixel point in the third CT scanning image; wherein,
So,ithe oil saturation value S of the pixel point i in the third CT scanning imageo；
CTx,iThe CT value of the pixel point i in the third CT scanning image is obtained;
CTdry,ithe CT value of a pixel point i in the first CT scanning image is obtained;
CTwet,iand the CT value of the pixel point i in the second CT scanning image is obtained.
13. The method of claim 11, wherein the determining the bubble point pressure value of the foam oil in the sample of porous media comprises:
acquiring the oil saturation distribution rate of each third CT scanning image based on the oil saturation values of each pixel point in each third CT scanning image in the at least one third CT scanning image;
and determining the quasi-bubble point pressure value of the foam oil in the porous medium sample based on the oil saturation distribution rate of each third CT scanning image in the at least one third CT scanning image.
14. The method of claim 13, wherein the oil saturation distribution rate of the third CT scan image is represented by an oil saturation frequency distribution curve;
accordingly, the determining the pseudo-bubble point pressure value of the foam oil in the porous medium sample comprises the following steps:
selecting at least one oil saturation frequency distribution curve which does not have monotonicity in a defined interval from the oil saturation frequency distribution curves of the at least one third CT scanning image; a set formed by third CT scanning images corresponding to the at least one oil saturation frequency distribution curve is used as a third CT scanning image set;
selecting a third CT scanning image with the maximum corresponding pressure value of the measuring container from the third CT scanning image set as a first target third CT scanning image; taking the pressure value of the measuring container corresponding to the first target third CT scanning image as a reference pressure value; taking the oil saturation frequency distribution curve of the first target third CT scanning image as a reference oil saturation frequency distribution curve;
selecting a sub-third CT scanning image set which corresponds to the measurement container and has a pressure value smaller than the reference pressure value and the number of the extreme points of the corresponding oil saturation curve different from the reference oil saturation frequency distribution curve from the third CT scanning image set;
selecting a third CT scanning image with the maximum oil saturation value corresponding to the peak value of the oil saturation frequency distribution curve from the sub-third CT scanning image set as a second target third CT scanning image; and taking the oil saturation distribution value of the second target third CT scanning image as the quasi-bubble point pressure value of the foam oil in the porous medium sample.
15. The method of claim 9, wherein the porous medium sample is a sand pack model sample and the measurement container is a sand pack tube or a core holder.
16. The utility model provides a simulate bubble point pressure value testing arrangement which characterized in that includes:
the device comprises a first CT scanning image acquisition unit, a second CT scanning image acquisition unit and a measurement container, wherein the first CT scanning image acquisition unit is used for acquiring a first CT scanning image of a porous medium sample through CT scanning after the porous medium sample is dried and loaded into the measurement container;
the second CT scanning image acquisition unit is used for injecting foam oil into the measuring container to enable the pressure value in the measuring container to be a first preset value; obtaining a second CT scanning image of the porous medium sample through CT scanning;
the third CT scanning image acquisition unit is used for gradually reducing the pressure value in the measuring container until the pressure value in the measuring container is a second preset value; and obtaining at least one third CT scan image of the porous medium sample by CT scan during the process of reducing the pressure value;
and the bubble point simulation pressure value determining unit is used for determining the bubble point simulation pressure value of the foam oil in the porous medium sample based on the first CT scanning image, the second CT scanning image and the at least one third CT scanning image.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710242780.4A CN107101773B (en) | 2017-04-14 | 2017-04-14 | Method and device for testing bubble point pressure value and quasi-bubble point pressure value |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710242780.4A CN107101773B (en) | 2017-04-14 | 2017-04-14 | Method and device for testing bubble point pressure value and quasi-bubble point pressure value |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107101773A CN107101773A (en) | 2017-08-29 |
| CN107101773B true CN107101773B (en) | 2019-07-09 |
Family
ID=59676002
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710242780.4A Active CN107101773B (en) | 2017-04-14 | 2017-04-14 | Method and device for testing bubble point pressure value and quasi-bubble point pressure value |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107101773B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107014839B (en) * | 2017-04-14 | 2019-11-08 | 中国石油天然气股份有限公司 | bubble point pressure value testing method and device |
| CN110320138B (en) * | 2018-03-30 | 2021-12-24 | 中国石油化工股份有限公司 | Device and method for measuring fluid saturation pressure and seepage capacity in porous medium |
| CN111693676B (en) * | 2019-03-12 | 2022-12-02 | 中国石油化工股份有限公司 | System and method for measuring bubble point pressure of crude oil in porous medium |
| CN110159261B (en) * | 2019-05-21 | 2022-07-26 | 中国石油大学(华东) | Device and method for measuring bubble point pressure in tight oil reservoir |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101366041A (en) * | 2005-12-22 | 2009-02-11 | 雪佛龙美国公司 | Method, system and program storage device for reservoir simulation utilizing heavy oil solution gas drive |
| CN102129548A (en) * | 2011-03-15 | 2011-07-20 | 中国石油大学(华东) | Method for acquiring and identifying structure images of foams flowing in porous medium in real time |
| CN102704913A (en) * | 2012-06-15 | 2012-10-03 | 中国石油天然气股份有限公司 | Experimental device and method for simulating exhaustion production of gas-containing thick oil by utilizing conical sand filling pipe |
| CN104481504A (en) * | 2014-11-11 | 2015-04-01 | 中国石油天然气股份有限公司 | Simulation experiment system and method for thick oil dissolved gas drive development |
| CN105137045A (en) * | 2015-07-20 | 2015-12-09 | 中国石油大学(华东) | Test apparatus of comprehensively determining formation of foam oil phenomenon in macroscopic seepage process and application thereof |
| US9470086B2 (en) * | 2013-12-18 | 2016-10-18 | King Fahd University Of Petroleum And Minerals | Inflow performance relationship for horizontal wells producing oil from multi-layered heterogeneous solution gas-drive reservoirs |
| CN106285583A (en) * | 2016-11-03 | 2017-01-04 | 西南石油大学 | A kind of microcosmic visualization displacement simulation system and using method thereof |
-
2017
- 2017-04-14 CN CN201710242780.4A patent/CN107101773B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101366041A (en) * | 2005-12-22 | 2009-02-11 | 雪佛龙美国公司 | Method, system and program storage device for reservoir simulation utilizing heavy oil solution gas drive |
| CN102129548A (en) * | 2011-03-15 | 2011-07-20 | 中国石油大学(华东) | Method for acquiring and identifying structure images of foams flowing in porous medium in real time |
| CN102704913A (en) * | 2012-06-15 | 2012-10-03 | 中国石油天然气股份有限公司 | Experimental device and method for simulating exhaustion production of gas-containing thick oil by utilizing conical sand filling pipe |
| US9470086B2 (en) * | 2013-12-18 | 2016-10-18 | King Fahd University Of Petroleum And Minerals | Inflow performance relationship for horizontal wells producing oil from multi-layered heterogeneous solution gas-drive reservoirs |
| CN104481504A (en) * | 2014-11-11 | 2015-04-01 | 中国石油天然气股份有限公司 | Simulation experiment system and method for thick oil dissolved gas drive development |
| CN105137045A (en) * | 2015-07-20 | 2015-12-09 | 中国石油大学(华东) | Test apparatus of comprehensively determining formation of foam oil phenomenon in macroscopic seepage process and application thereof |
| CN106285583A (en) * | 2016-11-03 | 2017-01-04 | 西南石油大学 | A kind of microcosmic visualization displacement simulation system and using method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107101773A (en) | 2017-08-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107101773B (en) | Method and device for testing bubble point pressure value and quasi-bubble point pressure value | |
| CN108490156B (en) | Test method for mixed gas oil displacement buried stock experiment under high-temperature and high-pressure conditions | |
| Pini et al. | Capillary pressure and heterogeneity for the CO2/water system in sandstone rocks at reservoir conditions | |
| CN104316554B (en) | Method for testing mobility of pore water of reservoir | |
| US7693677B2 (en) | Method of characterizing the distribution of the absolute permeability of a heterogeneous sample | |
| CN108627533A (en) | Fluid employs the nuclear magnetic resonance experiment method and device of feature in a kind of measurement porous media | |
| CN104729972B (en) | Determine the method and device of carbonate rock Gas And Water Relative Permeability | |
| CN106884635A (en) | Low, the extra-low permeability oil reservoirs CO of one kind2Drive the assay method of minimum miscibility pressure | |
| CN107741390A (en) | The physical simulating method that water filling induces microcrack Extending Law is reproduced under formation condition | |
| CN112081560B (en) | Development method of deep-sea high-temperature overpressure gas reservoir | |
| Hou et al. | Experiments on foam texture under high pressure in porous media | |
| CN114412429B (en) | Method for testing relationship between crack size and nuclear magnetic T2 of Brazilian splitting method | |
| CN105510207A (en) | Method for determining sensitivity of crack rock mass permeability in all directions to porosity | |
| CN105241901A (en) | Method for determining saturation of three-phase fluid | |
| CN107014839B (en) | bubble point pressure value testing method and device | |
| CN107402286A (en) | Delay swollen performance test experimental method in a kind of polymer microballoon rock core | |
| CN108959724B (en) | Method for designing acid damage process parameters of compact sandstone reservoir | |
| CN103983551A (en) | Two-dimensional visual seepage experiment apparatus stimulating in-layer homogeneity, and its experiment method | |
| CN113218834A (en) | Experimental device and method for quantitatively describing seepage damage of dense gas fracturing fluid and reservoir | |
| CN114460120A (en) | Simulation experiment device and method for dense oil imbibition replacement based on nuclear magnetic resonance | |
| CN115046897A (en) | Method and device for determining unsteady mass transfer efficiency and shape factor between matrix and crack | |
| CN108894773A (en) | Supercritical CO2Pressure break cement gel junction fracturing experimental facilities and method | |
| CN113075102A (en) | Method for establishing mathematical model of relation between spontaneous imbibition amount of porous medium and time | |
| CN106545335B (en) | Method for determining failure type development reasonable production pressure difference of tight oil reservoir | |
| CN109083630B (en) | Method for evaluating plugging performance of drilling fluid |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |