Retrieval of a Lightweight Fish Using Imaging and Downhole Telemetry

Abstract Retrieving a 1.5-in OD, 17-ft-long fish weighing approximately 150 lb from a horizontal well with 3.92-in casing posed significant operational challenges. The fish had remained in an H2S environment for over a year, creating uncertainties about its condition, corrosion risk, and mechanical integrity. Additional complications included unknown depth, possible debris and wire remnants above the fish, and an 87° deviation, all of which increased the likelihood of multiple fishing attempts and extended intervention time. To overcome these challenges, a 360° downhole camera was deployed via coiled tubing (CT) to visually confirm the fish's location and assess the surrounding environment. This imaging step provided critical insight into debris and wire remnants, enabling accurate planning and reducing uncertainty. Based on these findings, a customized fishing bottomhole assembly (BHA) was designed and equipped with a casing collar locator (CCL) and tension/compression tool (TCT) sensors. Real-time telemetry from these sensors ensured precise depth correlation and continuous monitoring during tagging and latching attempts, allowing immediate feedback for decision-making. The fish was identified and located at the depth of 8,072 ft in a highly deviated section and successfully retrieved in a single run. Imaging confirmed minimal obstruction and no significant deformation, while TCT readings validated engagement and indicated an approximately 150-lb weight change upon retrieval. Post-job analysis confirmed minimal wear on the fishing assembly, and the flawless completion of operation. This case demonstrates the effectiveness of integrating visual diagnostics with sensor-based feedback in CT fishing operations under sour and high-deviation conditions. The approach minimized operational risk, reduced intervention time, and avoided multiple fishing runs, which could have escalated cost and complexity. Lessons learned from this operation are broadly applicable to similar retrieval challenges, highlighting how advanced imaging and real-time telemetry enhance situational awareness, improve efficiency, and deliver significant value to the industry.