When a commercial diving and marine services company began planning the installation of a piggable wye to tie-in a new deepwater oil and gas system in the Gulf of Mexico for a major operator, it knew the job would be difficult. But with its 40 years of experience, it was up to the challenge. The first, most critical, phase of the program was to isolate pressure in a riser so that the wye could be safely installed.
It was imperative that this be carried out flawlessly, within the requisite timeframe. To do otherwise would delay plans to bring the new oil and gas system on-stream and produce “first oil” from the field. It was essential that the pressure be isolated to make certain that the divers, who would be working 228 meters (748 ft.) subsea near the open end of the line, would be safe.