Method for evaluating fracturing property of shale based on rock debris microscopic characteristics

Abstract

The invention discloses a method for evaluating fracturing property of shale based on rock debris microscopic characteristics. The method comprises the following steps: (1) taking the rock debris at specific depth in reservoir of an oil gas well; (2) acquiring the relative amount of total-rock minerals through X-ray diffraction test for the rock debris, and calculating a brittleness index I1 of the minerals; (3) testing the nanoindentation microcosmic mechanical parameters of the rock debris and calculating a microcosmic mechanical brittleness index I2 thereof; (4) calculating the surface crack fractal parameter of the rock debris through scanning electron microscope, thereby acquiring a fractal brittleness index I3; (5) performing 3D laser scanning on the rock debris and calculating the surface rough brittleness index I4; (6) weighting the above four brittleness indexes according to the practical condition of the oil field, thereby acquiring a comprehensive fracturing index I; (7) repeating the steps (1)-(6), calculating the fracturing indexes of the rock debris at different depths and drawing a whole-well comprehensive fracturing index longitudinal layout. According to the method provided by the invention, the comprehensive fracturing index of the shale rock debris can be acquired and the necessary basis is supplied for fracture selecting layer with core-taking difficulty or without core shale reservoir.

Description

Technical field [0001] The invention relates to a shale fracturability evaluation method based on the microscopic characteristics of rock cuttings, which belongs to the technical field of unconventional oil and gas development, and is especially aimed at the field of shale gas development. Background technique [0002] With the continuous rapid development of my country's national economy, my country has become the world's second largest crude oil importer, and its dependence on foreign sources has approached 60%. Therefore, while increasing the exploration and development efforts in new areas and areas of oil and gas, looking for new alternative energy sources has become an important strategic measure to ensure national energy security and national security. In order to realize the sustainable development of my country's energy industry, it is necessary to strengthen the exploration, development and utilization of unconventional oil and gas resources such as shale oil and gas, c...

AI Technical Summary

Problems solved by technology

[0011] The purpose of the present invention is to effectively evaluate the fracturability of shale reservoirs, overcome the defects of the prior art that only analyzes a single factor affecting the formation of fracture networks, the cost of experiments is expensive, the rate of drilling cores is low and time-consuming, etc., and proposes A fracturing evaluation method of shale based on the microscopic characteristics of cuttings

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