Methods and apparatus for determining carbon dioxide huff and puff volume in shale oil reservoirs

Abstract

This invention discloses a method and apparatus for determining the carbon dioxide huff and puff injection volume in shale oil reservoirs. The method includes: obtaining the injection rate of carbon dioxide gas in the shale oil reservoir and the gas concentration of carbon dioxide gas in the shale oil reservoir, wherein the gas concentration dynamically changes with diffusion depth; determining the target fracture area in the shale oil reservoir, wherein the target fracture area dynamically changes with cumulative well operating time; determining a first injection volume corresponding to the shale oil reservoir based on the injection rate and the target fracture area; determining a second injection volume corresponding to the shale oil reservoir based on the gas concentration and the target fracture area; and obtaining the target injection volume of the shale oil reservoir based on the first and second injection volumes. This invention solves the technical problems of large computational load, long time consumption, difficulty in fracture characterization, and inaccurate evaluation in related technologies, which mainly rely on conventional reservoir numerical simulation methods for designing carbon dioxide huff and puff injection volumes in shale oil reservoirs.

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