Abstract

The ability to optimally place a well in the target horizon and to remain in the sweet spot throughout the drain length is a major challenge in a brownfield with varying fluid contacts, such as the oil-water contact (OWC) or gas-oil contact (GOC). To mitigate drilling risks and optimize drilling parameters, early predictions of fluid contacts play a pivotal role. To address this, a pilot hole is drilled to determine fluid contacts and after abandoning it, the well is landed in the target zone by drilling a separate hole. These pilot holes are time consuming (5-7 rig days), which results in significant cost particularly in offshore environment where rig cost is very high. Panna field, located in offshore on the western coast of India, hosts the Bassein Formation, which is a carbonate reservoir with a thin oil rim and varying fluid contacts. Accurate placement of the horizontal section within the thin oil column is thus critical. The Reservoir Navigation System from Look Ahead Deep Resistivity While Drilling (LADRWD) can provide early, accurate boundary detection, enabling precise landing in the sweet spot. The tool uses low-frequency, omnidirectional, and azimuthal resistivity measurements to provide a real-time, 360° view of the wellbore, enabling detection, measurement, and visualization of the reservoir architecture and multiple bed boundaries from 150 ft (45.7 m) away. LADRWD tool was deployed in three wells of the Panna field, and through early and accurate detection of fluid contacts, precise landing was achieved.