RIASSUNTO
As operators in the Appalachia basin explore the Utica formation that underlies the previously-developed Marcellus shale, economic and environmental drivers have pushed drilling rigs to their limits in delivering wells that are both deeper and have longer lateral sections. These extended-reach lateral wells, with total measured depths (TMD) exceeding 18,000 ft, impose new completions challenges stemming from technical limits and the utilization of new technologies. This paper will demonstrate the need to adapt while dealing with new constraints. Specifically, this paper will report on the successful use of e-line, a tractor, and a magnet to retrieve a fish from plug-and-perf operations in an extended-reach lateral.
One major challenge in performing a plug-and-perf completion on the extended-reach lateral in this case study was that the toe of the well extended further than could be cost-effectively cleaned out with a service rig or coiled tubing. Therefore, large-bore cast iron permanent frac plugs, which are designed to be produced through, were used to isolate frac stages in the toe. Before pumping a subsequent stage, a dissolvable ball was seated on the plug to isolate the previously fractured stages.
While plugging and perforating, the wireline adapter kit of the plug setting tool backed off the toolstring, creating a fish above the plug. It was unclear if the adapter kit was still whole or had broken into multiple components. The challenge in recovering the fish was that if it had disassembled, smaller components of the assembly could potentially slip through the bore of the recently set plug. If this occurred, the plug would need to be milled before a fishing attempt could be made. Therefore, it was concluded that the fishing tools needed to be able to delicately engage the fish but still achieve a sufficient bite to hold the fish as it was dragged up the lateral. An overshot tool conveyed on coiled tubing was deemed too aggressive. Similarly, pumping down a wireline fishing tool was dismissed as the force from the pump down could potentially push the fish through the bore of the frac plug. Therefore, the decision was made to tractor-convey a rare earth magnet on e-line. This method successfully retrieved the fish on its first run, saving at least 3 days compared to the next-best recovery method.
This paper will detail the planning and execution of this fishing operation in order to provide insights for planning other extended-reach lateral completions. Specifically, this paper will show that existing technologies can be employed to overcome the challenges associated with fishing in extended-reach laterals.