This paper examines techniques necessary to fish coiled tubing (CT) with internal weld seams in a live well environment without back pressure valves (BPVs) using a hydraulic workover unit (HWO). The challenges of placing barriers in internal seamed CT verses using the slip and shear method is addressed.
The discussed onshore operation was completed August 2013 in North America. Using the techniques described, a 14,000-ft (4267 m) 2-in. (50.8-mm) CT fish was successfully removed from a well with an average surface pressure of 5,500 psi. This was achieved by first opening the blind rams, snubbing in, and dressing off the CT fish. Next, the CT fish was latched with an overshot and a pull test was performed, pressure was equalized, and the slip and pipe rams were opened. Following, the CT fish was picked up and moved to a desired location in the blowout preventer (BOP) stack (approximately 51 ft 4 in.). The slip rams were then closed and a weight check was performed. The pipe rams and inverted rams were then closed. The CT fish was shear/cut, the pipe was picked up and the blind rams were closed. This was concluded by laying down the fish and the process was repeated 276 times with an average cut of 50 ft. The HWO fishing procedures consisted of 541 hours without any health, safety, or environment (HSE) incidents, accidents, injuries, or job failures.