A visual simulation shale micro-fracture plugging ability test system and its test method

Abstract

The invention relates to a visual simulation shale micro-crack plugging capacity test system and a visual simulation shale micro-crack plugging capacity test method. Displacement evaluation experiment is performed on a single or combined micro-crack rock sample by a solution or a drilling fluid which contains the plugging agents with different concentrations and different types at different experiment conditions, such as pressure differences and times, indexes, such as the invasion depth, are compared, the formation conditions of inner mud cakes in drilling are directly described, and microscopic observation and analysis are performed on percolation substances invade into the micro-cracks by utilizing amplification imaging instruments, such as a high-definition microscope, so that the plugging mechanisms and the effects of various drilling fluid plugging agents and drilling fluids are analyzed and researched intuitively and microscopically, a proper drilling fluid plugging agent is selected preferably, a drilling fluid system formula is optimized, the problem about the experimental conditions that the visual simulation evaluation cannot be performed on shale micro-crack plugging in the past is solved, and a new evaluation experimental research means is provided for related research and production in the technical field of fractured shale strata borehole wall stability in petroleum engineering.

Description

technical field

[0001] The present invention relates to the field of petroleum exploration and development experimental equipment, more specifically, relates to a visual simulation evaluation device and usage method of shale micro-fracture plugging ability, which can be used in the research of well wall stability technology in petroleum engineering, and can be visualized and simulated to evaluate downhole Plugging ability of drilling fluid plugging agent to shale micro-fractures under static conditions. Background technique

[0002] The problem of wellbore stability is a worldwide problem in the process of oil drilling, which seriously affects normal operations and causes a large amount of economic losses every year. Statistics show that more than 90% of wellbore instability problems occur in shale formations, of which Hard and brittle shale formations with micro-fractures account for about two-thirds, and wellbore instability in this formation is a common and difficult prob...

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