In Western Australia, the customer was faced with an onshore well that could not be P&A using conventional methods to meet regulatory compliance because of a parted or collapsed casing and formation obstructions preventing any tools from penetrating beyond the 7-in casing at 780 m [2,559 ft]. Previously, the customer conducted a feasibility study for abandonment via wellbore intersection, akin to a relief-well intervention. This complex task required precise directional surveys in a magnetic interference zone, combined with passive magnetic ranging (PMR) and active magnetic ranging (AMR) to accurately position the intercept well. The high inclination of the intercept location added further complexity, necessitating advanced gyroscopic technologies for real‑time, close-to-bottom surveys.
SLB deployed its Quest GWD technology via GyroLink service across the key 12¼-in hole section drilling assemblies—both the RSS and motor BHA—with the TruLink service. These integrated configurations enabled precise adherence to the directional plan, delivered definitive dynamic surveys eliminating static surveys, and supported active position monitoring using PMR while drilling. The approach enhanced directional control and situational awareness throughout the operation, contributing to improved well placement accuracy and efficient drilling.
Gyro surveys were obtained closer to the bottom of each drilled interval and correlated with AMR results for precise wellbore positioning. This, combined with the GyroLink service, ensured accurate planning and execution of each interval, culminating in a successful intercept within the required envelope. The final trajectory was aligned to provide the necessary toolface orientation for subsequent casing milling operations.
