Innovative Execution of a Complex Rigless Well Intervention in an ERD Well Using Slim Tractor BHA and High Mast in Cambay Offshore Field

This paper details the successful planning and execution of a complex rigless well intervention in an Extended Reach Drilling (ERD) well located in the Cambay offshore field, India. The objective was to diagnose the root cause of high water cut and restore oil production by isolating water-producing zones using advanced production logging and mechanical intervention tools, despite significant operational and infrastructure challenges. The subject well is a high-angle, multi-zone horizontal ERD well with a measured depth exceeding 3,600m and deviation approaching 82°. Following a sharp increase in water cut (>95%), initial diagnostic and conveyance attempts using conventional tools were unsuccessful due to internal completion restrictions and the well's challenging trajectory. The intervention team adopted a custom-engineered 2-1/2-in. slim-profile electric-line tractor designed to navigate through the well specific restrictions and tractored successfully in a 5-1/2-in. lower completion. The Multi Array production logging tool, featuring array of tools, was specifically selected due to the high deviation of the well, where conventional single sensor tools typically fail to provide reliable results. This configuration allowed for precise fluid profiling and accurate detection of segregated multiphase flow in the horizontal section. Due to rig up height constraints on the offshore platform, a 90-ft portable mast—the first of its kind in the Cambay Basin—was deployed and validated by third party structural studies & engineering evaluations. Detailed risk assessments and weather-specific contingency plans ensured safe operations. Based on production logging interpretation, two sleeves contributing high water influx were selectively closed using a 2-1/8-in. high- expansion stroker. Post-intervention, the well achieved a stabilized oil production of ~590 BOPD with a reduced water cut of 75%, with zero HSE incidents or Non-Productive Time (NPT). Novel/Additive Information: This case marks the first successful integration of slim e-line tractor conveyance, multi-array production logging, and mechanical zonal isolation in an ERD well from a rig up constrained offshore platform using a 90-ft portable mast. It establishes a replicable model for safe, cost-effective rigless diagnostics and zonal remediation in mature offshore assets.