Abstract
This study addresses the critical challenge of extending the economic life of mature fields characterized by high water cuts and heterogeneous drainage. Focusing on the “X” field (PreCaspian Basin), the research evaluates the limitations of conventional sidetracking (ST) versus advanced Multilateral Drilling (MLD). Forensic analysis of production logs from existing wells reveals that single-bore sidetracks suffer from rapid sediment accumulation and mechanical window deformation. Crucially, an integrity assessment using azimuthal acoustic scanning (VAK-SK) identified a systemic failure in liner cementing (46% poor bonding) attributed to gravitational casing eccentricity. To mitigate these risks, this paper proposes an engineered TAML Level 4 dual-lateral design integrating Rotating Liner Technology and Passive Inflow Control Devices (ICD). Theoretical modeling confirms that ICDs neutralize the heel-toe effect, while rotation ensures zonal isolation. Economic analysis demonstrates that despite a 60% CAPEX premium, the MLD strategy yields a positive NPV by Year 3 and extends the plateau production period. The study provides a validated framework for selecting junction complexity in fields with weak formation integrity.