In the Vaca Muerta wells, operators face daily difficulties due to casing issues. The industry presently lacks efficient early-stage detection approaches for addressing these problems, which often results in decision-making only after the event has occurred. This situation leads to further operational complications and adverse economic consequences. In our research, we present a novel tool designed to detect anomalies, which will enable us to establish a contingency plan for effective response.
Unusual casing collar locator (CCL) readings sometimes indicate where the wireline gets stuck in later runs. Although not specifically designed for detecting casing issues, irregular CCL fluctuations might hint at problems with casing diameters. Initially, we applied an isolation forest-based anomaly detection algorithm to identify CCL disturbances, but not in real-time. In a recent pad, pump-down runs could not be executed due to casing restrictions. This incident led us to shift the frac fleet and use a multi-finger caliper tool. The results allowed us to tunned the anomaly detector tool (ADT). Blind tests on historical stages showed our ADT successfully identified problematic stages from casing restrictions. The research seeks to use this tool as a first step to make informed decisions on contingency plans to mitigate related problems to this.
Casing deformation has been observed in conventional and unconventional reservoirs, at the recent years has gained more attention in shale developments, several cases has been reported in Canada, China and Argentina. It is recommended to review two technical publications to have a better understanding about the possible causes of casing deformation generation. The first one, Casero and Rylance (2020) presented an initial approach about casing deformation that can be influenced by: a- well construction (tubular, cement), b-subsurface (tectonics and rock properties) and c-operations; and several case histories around the world. The second one, Russel (2021) shown different diagnostic tool to collect information about deformation; mechanisms and root causes in unconventional well focusing on cases with slip on natural fractures and bedding planes.
