Abstract
Plug-and-perf multizone fracturing remains a dominate completion method in the Haynesville shale. Removing the composite frac plugs (CFP) utilizing coiled tubing (CT) remains a challenging operation with increased risks due to extreme well environments. Operations completed using older, conventional methodologies increase the likelihood of stuck CT events. These stuck pipe events add considerable cost to the completion through fishing, lost production time, or worse, loss of the entire well.
In one such instance while milling CFPs, the downhole tools seized resulting in loss of circulation, subsequently leading to a stuck in hole event. Wireline severing tools cut the pipe in the vertical section, leaving over 4,500 ft of 2 in. CT in the lateral. Removing the CT fish without damaging the formation was paramount to the long-term profitability of the well. Conventional fishing methods were considered, but unfavorable economics in addition to the risk of formation damage lead to the selection of a hybrid approach combining wireline, snubbing, slickline and CT.
The fish was successfully latched using a snubbing unit, providing a conduit for 1-¼ in. CT to convey a severing tool to free the larger coil in the lateral section. This enabled the continuous removal of the 2 in. CT under live well conditions, saving over 4 million dollars and 55 days compared to conventional techniques. Following the stuck pipe event, a complete change in the drillout procedure was implemented, increasing efficiency while minimizing the risk of a repeat event.