Fracturing Breakthrough and Comprehensive Evaluation of CP1 Well in Yingxiongling Shale Oil Reservoir, Qaidam Basin

The Yingxiongling shale oil reservoir in the Qaidam Basin poses unique challenges due to its high stress differentials, steep stress gradients, abundant limy dolomite content, strong heterogeneity, and underdeveloped natural fractures. This paper conducts a comprehensive geoscience-to-engineering analysis of the CP1 well to offer insights for reservoir stimulation and production optimization. Results indicate that the "single well proactive interference and control" fracturing plan effectively manages fracture propagation. Comparison of liquid production across lithofacies reveals laminated limy-dolomitic shale's strong liquid supply capacity and layered limy-dolomitic shale's high oil production capacity. The spatial relationship between these lithofacies creates a distinctive enrichment and seepage pattern, forming the geological basis for maximizing the oil production potential of the Yingxiongling continental shale oil reservoir. Additionally, this configuration regulates post-fracturing oil and water production dynamics, emphasizing the significance of the interbed combination of laminated limy-dolomitic shale and layered limy-dolomitic shale as favorable lithofacies. 1. INTRODUCTION China possesses abundant continental shale oil resources, with recent years witnessing significant advancements in exploration and development, particularly in the Jungar, Ordos, Songliao, and Qaidam basins (Zhao et al., 2021; Jin et al., 2021; Fu et al., 2022; He et al., 2022). Volume fracturing technology is the key to achieving efficient development of unconventional oil and gas reservoirs. With the goal of maximizing the effective stimulated reservoir volume (SRV) and single-well control of EUR, guided by the idea of geoscience-to-engineering integration, we targeted the characteristics of high stress differentials, steep stress gradients, high limy dolomite content, strong heterogeneity, and underdeveloped natural fractures in the Yingxiongling continental shale oil reservoir (Jiang et al., 2023). Following a "technically prudent, parameter aggressive" approach, we employed a core volume fracturing technique that includes "dense cutting of multiple segments and clusters, extreme flow limiting perforation, high pumping rate, high intensity continuous sand addition with slickwater with variable viscosity". This approach resulted in the formation of a complex network of fractures, establishing an artificial seepage system to enhance single-well production.