阅读说明：本技术 一种测定岩屑流体体积和饱和度的方法 (Method for measuring volume and saturation of rock debris fluid ) 是由 公言杰 赵孟军 卓勤功 柳少波 万佳林 于 2020-05-11 设计创作，主要内容包括：本发明提供了一种测定岩屑流体体积和饱和度的方法。该方法包括：对待测岩屑进行CT扫描得到待测岩屑的灰度值分布图像；提取待测岩屑中的流体,将提取出来的流体进行CT扫描得到流体的灰度值分布；根据流体的灰度值分布以及待测岩屑的灰度值分布图像,确定出待测岩屑中的流体体积。测定岩屑流体饱和度的方法包括：利用上述测定岩屑流体体积的方法确定待测岩屑中的流体体积；确定待测岩屑的孔隙体积；利用确定的待测岩屑中的流体体积以及待测岩屑的孔隙体积计算得到岩屑流体饱和度。该方法无需直接测量流体的体积,可有效避免因抽提过程中流体的污染和损失造成流体体积测量不准的问题。(The invention provides a method for measuring volume and saturation of rock debris fluid. The method comprises the following steps: carrying out CT scanning on the rock debris to be detected to obtain a gray value distribution image of the rock debris to be detected; extracting fluid in the rock debris to be detected, and carrying out CT scanning on the extracted fluid to obtain the gray value distribution of the fluid; and determining the volume of the fluid in the rock debris to be detected according to the gray value distribution of the fluid and the gray value distribution image of the rock debris to be detected. The method for determining the fluid saturation of the rock debris comprises the following steps: determining the volume of the fluid in the rock debris to be measured by using the method for determining the volume of the fluid in the rock debris; determining the pore volume of the rock debris to be detected; and calculating to obtain the fluid saturation of the rock debris by using the determined fluid volume in the rock debris to be detected and the pore volume of the rock debris to be detected. The method does not need to directly measure the volume of the fluid, and can effectively avoid the problem of inaccurate measurement of the volume of the fluid caused by pollution and loss of the fluid in the extraction process.)

1. A method of determining the volume of fluid in a rock fragment, wherein the method comprises:

carrying out CT scanning on the rock debris to be detected to obtain a gray value distribution image of the rock debris to be detected;

extracting fluid in the rock debris to be detected, and carrying out CT scanning on the extracted fluid to obtain the gray value distribution of the fluid;

and determining the volume of the fluid in the rock debris to be detected according to the obtained gray value distribution of the fluid and the gray value distribution image of the rock debris to be detected.

2. The method according to claim 1, wherein the determining of the fluid volume in the rock debris to be detected is performed according to the obtained gray value distribution of the fluid and the gray value distribution image of the rock debris to be detected by: and determining the part belonging to the fluid in the obtained gray value distribution image of the rock debris to be detected according to the obtained gray value distribution of the fluid, further determining that the number of pixels of the part belonging to the fluid in the gray value distribution image of the rock debris to be detected is the number of pixels of the fluid of the rock debris to be detected, and multiplying the scanning pixel volume by the number of pixels of the fluid of the rock debris to be detected to obtain the fluid volume of the rock debris to be detected.

3. The method of claim 1, wherein the extracting the fluid from the rock debris is performed by distilling the rock debris.

4. The method of claim 3, wherein extracting the fluid in the rock debris to be tested is performed by: the water in the debris is evaporated by heating, the water vapor is condensed and collected, and then the oil is extracted by the solvent.

5. The method of claim 1, wherein the extracted fluid is placed in a glass container for CT scanning during CT scanning of the extracted fluid;

preferably, the glass container is a slender glass tube, and the liquid level of the extracted fluid in the slender glass tube is not lower than 2 cm;

more preferably, the liquid level height is 2cm-3 cm;

more preferably, the tube inner diameter of the elongated glass tube is 5 mm.

6. A method of determining fluid saturation of a formation cuttings, the method comprising:

A. determining the fluid volume in the rock debris to be tested by using the method for determining the fluid volume of rock debris according to any one of claims 1 to 5;

B. determining the pore volume of the rock debris to be detected;

C. and D, calculating to obtain the rock debris fluid saturation by using the fluid volume in the rock debris to be detected determined in the step A and the pore volume of the rock debris to be detected determined in the step B.

7. The method of claim 6, wherein step B is achieved by:

determining the total volume of the rock debris to be detected according to the gray value distribution image of the rock debris to be detected, which is obtained in the process of determining the volume of the fluid in the rock debris to be detected in the step A;

processing the rock debris to be detected to be in a fluid-free state, then carrying out CT scanning to obtain a gray value distribution image of the rock debris skeleton to be detected, and determining the volume of the rock debris skeleton to be detected according to the gray value distribution image of the rock debris skeleton to be detected;

and determining the pore volume of the rock debris to be detected according to the determined total volume of the rock debris to be detected and the determined volume of the rock debris framework to be detected.

8. The method according to claim 7, wherein determining the total volume of the rock fragments to be detected from the gray value distribution image of the rock fragments to be detected is performed by: and determining the pixel number of the obtained gray value distribution image of the rock debris to be detected, namely the total pixel number of the rock debris to be detected, and multiplying the scanning pixel volume by the total pixel number of the rock debris to be detected to obtain the volume of the rock debris to be detected.

9. The method of claim 7, wherein determining the volume of the rock fragment skeleton to be tested from the gray value distribution image of the rock fragment skeleton to be tested is performed by: and determining the number of pixels of the obtained gray value distribution image of the rock fragment framework to be detected, namely the number of pixels of the rock fragment framework to be detected, and multiplying the scanning pixel volume by the number of pixels of the rock fragment framework to be detected to obtain the volume of the rock fragment framework to be detected.

10. The method of any one of claims 6-9, wherein the method of determining fluid saturation of a debris comprises:

carrying out CT scanning on the rock debris to be detected to obtain a gray value distribution image of the rock debris to be detected, and determining the volume of the fluid in the rock debris to be detected by using the method for determining the volume of the fluid in the rock debris to be detected;

distilling and extracting fluid in the rock debris to be detected, and placing the extracted fluid into a slender glass tube for CT scanning to obtain the gray value distribution of the fluid; wherein the extraction is to evaporate water in the rock debris by heating, condense and collect water vapor, and then extract oil by using a solvent; the elongated glass tube can realize that the height of the extracted fluid is not less than 2cm after the extracted fluid is placed in the elongated glass tube;

determining the volume of the fluid in the rock debris to be detected according to the obtained gray value distribution of the fluid and the obtained gray value distribution image of the rock debris to be detected;

processing the rock debris to be detected to be in a fluid-free state, then carrying out CT scanning to obtain a gray value distribution image of the rock debris skeleton to be detected, and determining the volume of the rock debris skeleton to be detected according to the gray value distribution image of the rock debris skeleton to be detected;

determining the pore volume of the rock debris to be detected according to the determined total volume of the rock debris to be detected and the determined volume of the rock debris framework to be detected;

and calculating to obtain the fluid saturation of the rock debris by using the determined volume of the fluid in the rock debris to be detected and the determined pore volume of the rock debris to be detected.

Technical Field

The invention belongs to the technical field of petroleum and geology, and particularly relates to a method for measuring volume and saturation of rock debris fluid.

Background

In oil and gas exploration, the measurement of fluid saturation parameters is a necessary link in oil and gas exploration and development. Mastering the fluid saturation of an oil layer is the basis for knowing the oil storage condition of the oil layer, estimating the reserve and analyzing the production condition of an oil field. Some currently most common determination technologies are clearly given in the China oil and gas industry standard SY/T5336-2006, such as: (1) direct measurement methods, including atmospheric dry distillation; distillation extraction (full diameter rock samples); distillation extraction (plug rock samples); pressure maintaining core analysis; solvent washing method; sponge coring; a method for analyzing a gypsum-containing core; coal sample analysis, and the like. However, the method mainly aims at regular core samples, has high requirements on the size of a test sample, and cannot measure the fluid saturation of rock debris. (2) An indirect measurement method is mainly used for well logging explanation (a relation between a resistivity logging curve and fluid saturation is established through the resistivity logging curve and the like), however, the resistivity logging usually has a plurality of influence factors, a logging response value is not only influenced by the fluid saturation, but also interfered by other factors, a rock-electricity experiment needs to be carried out to calibrate corresponding parameters, a rock-electricity experiment needs a rock core, and the fluid saturation is not accurately calculated without the logging of the rock-electricity experiment of the rock core.

While current oil and gas field drilling technology continues to improve, the cost of coring is very high, and most oil field well locations do not core, i.e., there is no core sample, only a rock chip sample. In addition, along with the current development of oil and gas exploration to the deep layer, the deep complex reservoir stratum has been more and more emphasized, the deep reservoir stratum physical properties are very complex, the drilling difficulty is very high, the cost is extremely high, the coring cost is higher, most deep well positions are also difficult to core, and rock data are mainly rock debris.

The measurement of the fluid saturation of the rock debris is difficult mainly because the rock debris sample has small volume and irregular shape. The fluid content in the rock debris is trace and even trace, and the determination is difficult by adopting a conventional method. Even if a high-precision flowmeter is used for measurement, a large error exists due to the small mass of the flowmeter. In addition, the fluid is separated from the rock debris, the most effective method at present is extraction, the fluid is polluted and lost in the process, and the trace fluid is difficult to remain after the extraction is finished, so that the measurement cannot be carried out. In addition, the irregular volume of the rock debris brings great difficulty to the calculation of the pore volume of the rock debris.

In conclusion, in reservoir research, how to effectively measure the fluid saturation of rock debris and exert the rock data function to the maximum extent is very important and urgent for exploration accuracy and economy. The problem of how to measure the fluid saturation of fine rock debris is more and more emphasized by petroleum workers, but at present, no well-known method exists at home and abroad.

Disclosure of Invention

The invention aims to provide a method for measuring the volume of fluid in rock debris, which does not need to directly measure the volume of the fluid and can effectively avoid the problem of inaccurate measurement of the volume of the fluid caused by pollution and loss of the fluid in the extraction process.

In order to achieve the above object, the present invention provides a method for determining a volume of fluid in a rock debris, wherein the method comprises:

carrying out CT scanning on the rock debris to be detected to obtain a gray value distribution image of the rock debris to be detected;

extracting fluid in the rock debris to be detected, and carrying out CT scanning on the extracted fluid to obtain the gray value distribution of the fluid;

and determining the volume of the fluid in the rock debris to be detected according to the obtained gray value distribution of the fluid and the obtained gray value distribution image of the rock debris to be detected.

In the method for determining the volume of the fluid in the rock debris, preferably, determining the volume of the fluid in the rock debris to be measured according to the obtained gray value distribution of the fluid and the obtained gray value distribution image of the rock debris to be measured is implemented by: determining the part of the obtained gray value distribution image of the rock debris to be detected, which belongs to the fluid, according to the obtained gray value distribution of the fluid, further determining that the number of pixels of the part of the obtained gray value distribution image of the rock debris to be detected, which belongs to the fluid, is the number of pixels of the fluid of the rock debris to be detected (the number of pixels of the part of the gray value distribution image of the rock debris to be detected, which belongs to the fluid, can be determined by utilizing CT image processing software, for example, by utilizing Avizo software), and multiplying the scanning pixel volume by the number of pixels of the fluid of the rock debris to be detected to obtain the fluid volume of the rock debris to be detected.

In the method for determining the volume of the fluid in the rock debris, preferably, the fluid in the rock debris to be determined is extracted by distilling the rock debris; more preferably, the water in the debris is evaporated by heating, the water vapor is condensed and collected, and then the oil is extracted by the solvent.

In the method for determining the volume of the fluid in the rock debris, preferably, the extracted fluid is placed in a glass container for CT scanning during the CT scanning of the extracted fluid; more preferably, the glass container is an elongated glass tube, and the liquid level of the fluid placed in the elongated glass tube is not lower than 2 cm; further preferably, the liquid level height is 2cm to 3 cm. In a specific embodiment, the elongated glass tube has a tube inner diameter of 5 mm. The difference between the fluid and the glass is obvious, and the trace fluid in the glass container with the micro-fine pipe diameter can be distinguished very obviously under CT scanning, so that the accuracy of determining the gray value distribution of the fluid is improved, and the accuracy of determining the volume of the fluid in the rock debris to be detected is improved.

In the method for measuring the volume of the fluid in the rock debris, the rock debris to be measured can be extracted from the fluid by a conventional method, for example, a conventional extraction method can be adopted.

In the method for measuring the volume of fluid in rock debris, the image obtained after CT scanning is a gray value distribution image, and normally, the gray value of the high-density component is bright white, and the gray value of the low-density component is gray black.

The invention also provides a method for measuring the fluid saturation of the rock debris, wherein the method comprises the following steps:

A. determining the volume of the fluid in the rock debris to be measured by using the method for determining the volume of the fluid in the rock debris;

B. determining the pore volume of the rock debris to be detected;

C. and D, calculating to obtain the rock debris fluid saturation by using the fluid volume in the rock debris to be detected determined in the step A and the pore volume of the rock debris to be detected determined in the step B.

In the above method for determining the fluid saturation of rock debris, preferably, step B is performed by:

determining the total volume of the rock debris to be detected according to the gray value distribution image of the rock debris to be detected, which is obtained in the process of determining the volume of the fluid in the rock debris to be detected in the step A;

processing the rock debris to be detected to be in a fluid-free state, then carrying out CT scanning to obtain a gray value distribution image of the rock debris skeleton to be detected, and determining the volume of the rock debris skeleton to be detected according to the gray value distribution image of the rock debris skeleton to be detected;

and determining the pore volume of the rock debris to be detected according to the determined total volume of the rock debris to be detected and the determined volume of the rock debris framework to be detected.

More preferably, the determination of the total volume of the rock debris to be detected according to the gray value distribution image of the rock debris to be detected is realized by the following steps: the number of pixels of the obtained gray value distribution image of the rock debris to be detected, that is, the total number of pixels of the rock debris to be detected is determined (the number of pixels of the obtained gray value distribution image of the rock debris to be detected, that is, the total number of pixels of the rock debris to be detected can be determined by using CT image processing software, for example, Avizo software is used for determining), and the volume of the scanned pixels is multiplied by the total number of pixels of the rock debris to be detected, so that the volume of the rock debris to be detected can be obtained.

More preferably, the determination of the volume of the rock fragment framework to be detected according to the gray value distribution image of the rock fragment framework to be detected is realized by the following steps: the number of pixels of the obtained gray value distribution image of the rock fragment framework to be detected, that is, the number of pixels of the rock fragment framework to be detected is determined (the number of pixels of the obtained gray value distribution image of the rock fragment framework to be detected, that is, the number of pixels of the rock fragment framework to be detected can be determined by using CT image processing software, for example, Avizo software is used for determining the number of pixels of the obtained gray value distribution image of the rock fragment framework to be detected), and the volume of the scanned pixels is multiplied by the number of pixels of the rock fragment framework to be detected, so that the volume of the rock fragment framework to be detected can be obtained.

In one embodiment, the method for determining fluid saturation of rock debris comprises:

carrying out CT scanning on the rock debris to be detected to obtain a gray value distribution image of the rock debris to be detected, and determining the volume of the fluid in the rock debris to be detected by using the method for determining the volume of the fluid in the rock debris to be detected;

distilling and extracting fluid in the rock debris to be detected, and placing the extracted fluid into a slender glass tube for CT scanning to obtain the gray value distribution of the fluid; wherein the extraction is to evaporate water in the rock debris by heating, condense and collect water vapor, and then extract oil by using a solvent; the elongated glass tube is capable of achieving a height of not less than 2cm (preferably 2-3cm) of the extracted fluid placed therein;

determining the volume of the fluid in the rock debris to be detected according to the obtained gray value distribution of the fluid and the obtained gray value distribution image of the rock debris to be detected;

processing the rock debris to be detected to be in a fluid-free state, then carrying out CT scanning to obtain a gray value distribution image of the rock debris skeleton to be detected, and determining the volume of the rock debris skeleton to be detected according to the gray value distribution image of the rock debris skeleton to be detected;

determining the pore volume of the rock debris to be detected according to the determined total volume of the rock debris to be detected and the volume of the rock debris skeleton to be detected determined in the step 4);

and calculating to obtain the fluid saturation of the rock debris by using the determined volume of the fluid in the rock debris to be detected and the determined pore volume of the rock debris to be detected.

The treatment of the fluid-free rock debris can be carried out in a conventional manner, for example, by drying the fluid-extracted rock debris.

The invention utilizes the characteristic that CT can carry out scanning treatment on a sample and the fluid in the sample without damage, carries out CT scanning on the fluid-containing rock debris, then extracts the fluid to obtain the fluid and carries out CT scanning, and determines the volume of the rock debris fluid through the fluid gray value distribution and the CT scanning image of the fluid-containing rock debris. The method and the device have the advantages that the gray value distribution range of the fluid is determined based on the CT scanning of the fluid independently, the content of the fluid is very loose, the technical scheme provided by the invention is that the gray value distribution range of the fluid is only required to be obtained when the fluid is subjected to the CT scanning, the volume metering error caused by loss and the like in the fluid extraction process is avoided, and the fluid volume can be obtained by processing the CT scanning data of the initial debris by using the gray value distribution range of the fluid. The invention further provides a method for measuring the fluid saturation of the rock debris, and the method for measuring the fluid volume of the rock debris is used for measuring the fluid volume of the rock debris so as to determine the fluid saturation of the rock debris. Compared with the prior art, the technical scheme provided by the invention has the following advantages:

1. the method for measuring the fluid saturation of the rock debris greatly saves the cost of rock physics research, the rock debris can be directly measured for the fluid saturation without core sampling, the sample size is not required, and the method is suitable for measuring various rock debris.

2. According to the technical scheme provided by the invention, the fluid information in the rock debris is obtained firstly, and then the fluid is extracted, so that the inaccuracy caused by the fact that the fluid is polluted or lost by the reagent in the fluid extraction process and then the measurement is carried out is avoided.

3. The technical scheme provided by the invention can simply and conveniently obtain the volume and saturation of the rock debris fluid, can effectively utilize oil field samples and data at home and abroad, and is easy to popularize and use in a large range.

4. The technical scheme provided by the invention firstly provides that the fluid is extracted and subjected to independent CT scanning to obtain the fluid gray distribution range, so that the accuracy of the result is ensured.

Detailed Description

The technical solutions of the present invention will be described in detail below in order to clearly understand the technical features, objects, and advantages of the present invention, but the present invention is not limited to the practical scope of the present invention.

Example 1

The present embodiments provide a method of determining a volume of fluid in a rock debris, wherein the method comprises:

1) carrying out CT scanning on the rock debris to be detected to obtain a gray value distribution image of the rock debris to be detected, wherein the gray value distribution range is 1-12360;

2) extracting fluid (oil and water) in the rock debris by adopting a distillation extraction mode (refer to an industrial standard SY-T5336-2006), specifically, evaporating water in the rock debris by heating, condensing water vapor for collection, and then extracting the oil by using a solvent carbon tetrachloride; placing the extracted oil and water in a slender glass tube (the inner diameter of the glass tube is 5mm) (the height of the extracted fluid in the slender glass tube is 2cm-3cm) to perform CT scanning, and obtaining the gray value distribution range of the oil and the water of 1-4640;

3) determining the part belonging to the fluid in the gray value distribution image of the rock debris to be detected obtained in the step 1) according to the gray value distribution of the fluid obtained in the step 2); further utilizing CT image processing software Avizo to determine that the pixel number of the part belonging to the fluid in the gray value distribution image of the rock debris to be detected is the fluid pixel number of the rock debris to be detected (about 0.445 multiplied by 10)⁸One), a pixel volume (2 μm) will be scanned³) Multiplying the number of the fluid pixels of the rock debris to be detected to obtain the fluid volume of the rock debris to be detected, wherein the fluid volume is 0.089 multiplied by 10⁹μm³。

Example 2

The embodiment provides a method for determining the fluid saturation of rock debris, wherein the method comprises the following steps:

A. determining the volume of the fluid in the rock debris to be measured by using the method for determining the volume of the fluid in the rock debris provided in the embodiment 1;

B. determining the pore volume of the rock debris to be detected, specifically: b1 determining the pixel number of the gray value distribution image of the rock debris to be detected obtained in the step A, namely the total pixel number of the rock debris to be detected (about 2.22 multiplied by 10) by utilizing CT image processing software Avizo⁹One), a pixel volume (2 μm) will be scanned³) Multiplying the total pixel number of the rock debris to be detected by the total pixel number of the rock debris to be detected to obtain the volume of the rock debris to be detected, and determining the total volume of the rock debris to be detected, wherein the total volume of the rock debris is 4.44 multiplied by 10⁹μm³(ii) a B2, drying the rock debris extracted from the fluid in the step A in an oven, performing CT scanning to obtain a gray value distribution image of the rock debris framework to be detected, wherein the gray value distribution range is greater than 4640 but less than or equal to 12360, and determining the number of pixels of the obtained gray value distribution image of the rock debris framework to be detected, namely the number of pixels (about 2.11 multiplied by 10) of the rock debris framework to be detected by utilizing CT image processing software Avizo⁹One), a pixel volume (2 μm) will be scanned³) Riding deviceDetermining the volume of the rock fragment framework to be detected according to the gray value distribution image of the rock fragment framework to be detected by using the pixel number of the rock fragment framework to be detected, wherein the total volume of the rock fragment framework is 4.22 multiplied by 10⁹μm³(ii) a B3, subtracting the volume of the skeleton of the rock debris to be detected determined in the step B2 from the total volume of the rock debris to be detected determined in the step B1 to determine the pore volume of the rock debris to be detected, wherein the pore volume of the rock debris to be detected is 2.2 multiplied by 10⁸μm³；

C. And B, calculating to obtain rock debris fluid saturation by using the volume of the fluid in the rock debris to be detected determined in the step A and the pore volume of the rock debris to be detected determined in the step B, wherein the rock debris fluid saturation is 40.45%.