Innovative assessment of CO2 storage potential in China's shale oil fracturing: A storage index-well layout approach

As global efforts to mitigate climate change intensify, CO 2 storage in shale oil reservoirs presents a promising avenue for reducing greenhouse gas emissions while enhancing oil recovery. However, accurate assessment of storage potential remains challenging, particularly in China’s diverse shale oil basins. This study introduces the Storage Index-Well Layout (SI-WL) method, a novel approach for evaluating CO 2 storage potential in shale oil reservoirs, and applies it to 12 major basins in China. Comparing this method with traditional and improved US-DOE methods demonstrates its superior reliability in estimating storage capacity under current technological conditions. Our analysis reveals a cumulative CO 2 storage potential of 5.69 × 10 8 t of liquid CO 2 across the studied basins, with the Bohai Bay Basin showing the highest capacity at 1.87 × 10 8 t. Scenario analysis from 2025 to 2060 identifies key factors influencing storage potential, including the proportion of wells using CO 2 fracturing and fracturing fluid performance. While current practices in China’s shale oil CO 2 fracturing achieve effective results, improving liquid CO 2 ’s viscosity and sand-carrying performance remains a significant challenge. This research provides valuable insights for shale oil CO 2 fracturing development and CO 2 emission reduction strategies, suggesting that technological advancements could significantly enhance CO 2 storage in the shale oil industry. • Developed a novel Storage Index-Well Layout (SI-WL) method for assessing CO 2 storage potential in shale oil reservoirs. • Quantified CO 2 storage capacity of 5.69 × 10 8 t across 12 major Chinese shale basins, with Bohai Bay Basin showing highest potential. • Demonstrated superior accuracy of SI-WL method compared to traditional US-DOE approaches through comprehensive validation. • Conducted scenario analysis (2025-2060) identifying key technological barriers in CO 2 fracturing development. • Provided strategic insights for improving liquid CO 2 ’s viscosity and sand-carrying performance in shale reservoirs.