A Quantitative Evaluation Method and Device for Tight Sandstone Reservoir Pore Structure

Abstract

The invention provides a quantitative evaluation method and device for the pore structure of tight sandstone reservoirs. Including: obtaining the target cast thin slice; extracting the cast thin slice image from the target cast thin slice; converting the cast thin slice image to an image of the RGB color mode, and making the target color the part with the largest area in the image; converting the RGB color mode Convert the image of the YCbCr color mode to the image of the YCbCr color mode; carry out color clustering processing on the image of the YCbCr color mode to obtain the image filled with the target color and the image filled with the non-target color; overlap the cast flake image with the image filled with the target color area as the pore structure of tight sandstone reservoirs. The invention also provides a quantitative evaluation device for the pore structure of tight sandstone reservoirs. The method and device of the present invention can accurately and quantitatively characterize the pore structure of tight sandstone reservoirs.

Description

technical field [0001] The invention relates to a quantitative evaluation method and device for pore structure, in particular to a quantitative evaluation method and device for the pore structure of tight sandstone reservoirs. Background technique [0002] With the long-term exploration and exploitation of conventional oil and gas fields in the world, most of the major oil fields have entered the later stage of development. From resource reserves to mining potential, they cannot meet the huge needs of the world's industrial development. Therefore, it has become an inevitable trend to extend exploration to unconventional oil and gas fields. At the same time, with the improvement of oil and gas drilling technology and the deepening of exploration work, the exploration of tight reservoirs is getting deeper and deeper. The research on tight sandstone gas is very important to the exploration and development of global unconventional oil and gas resources, and it is also an import...

AI Technical Summary

Problems solved by technology

[0009] The disadvantages of this method are: the direct image observation method is generally a qualitative description and analysis of the collected reservoir images, which is highly subjective and lacks quantitative description of the pore structure information

[0013] The disadvantage of this method is that the quantitative analysis of the pore structure using software requires the extraction object to have a high color contrast, obvious differences, and clear edges (for example, the overall color of tight sandstone belongs to the gray-white-gray-blue-gray-brown range, The contrast is poor, and due to the existence of mud, as well as the existence of compaction and dissolution, the edges of particles and pores are not clear, and there is a phenomenon of mixing, which is not suitable for the extraction of existing software); at the same time, software extraction also requires The extracted target objects account for a large proportion and are easy to distinguish (the tight sandstone reservoirs of the research object have relatively low porosity, and the proportion of pores filled by castings under the view of an ore slice is often less than 10%, which cannot be used conventional software for identification and extraction);

However, common measurement methods are costly, require professional experimental equipment for measurement, and are complicated and time-consuming; moreover, the utilization rate of image pore information by common methods is extremely low, and most of them mainly use the porosity obtained from the test. , permeability data, or some pore structure parameters for later analysis

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