Comparative Look at Wellbore/Rock Connection Techniques: An Integrated Perspective from Stimulation, Intervention, and Laboratory Research

Summary Effective fracture initiation in tight reservoirs characterized by high tectonic stress remains a persistent challenge, often exacerbated by conventional perforation methods failing to achieve rock breakdown. This leads to unsuccessful fracture placement and reduced production. The research presented here comparatively evaluates three primary wellbore/rock connection techniques—conventional perforating (CP), abrasive perforating (AP) via coiled tubing (CT), and circular notching—through comprehensive laboratory experiments, theoretical context, and field application analyses from intervention and stimulation perspectives. Laboratory experiments performed on cement and limestone block samples under true triaxial-stress conditions demonstrated the theoretical superiority of circular notches, reducing fracture initiation pressures (FIPs) by up to 40% compared with perforation holes. Field evaluations reinforced these laboratory findings, showcasing significant injectivity improvements with AP and circular notching over CP, with injectivity enhancements up to 628% in clastic formations and up to 400% in carbonate reservoirs. Theoretical advancements detailed in this study introduced a novel qualitative metric, connection transmissibility (Tc), enhancing diagnostic capabilities and intervention design effectiveness. To ensure consistency between laboratory and field applications, systematic workflows using optimized CT bottomhole assemblies (BHAs) and real-time downhole telemetry were developed, offering precise operational guidelines. These innovative workflows facilitate appropriate intervention and stimulation designs, ultimately guiding engineers to enhance operational efficiency, reduce completion costs, and improve overall reservoir productivity.