IMI Critical Engineering has delivered a bespoke solution, which has been proven to be able to withstand the unique demands of deep-sea oil and gas extraction over extended periods. There is an estimated extraction of 125 000 bpd of oil and 70 million ft3/d gas at the Tahiti facility in the Gulf of Mexico, where valuable energy resources are in abundance at extreme depths. Therefore, equipment needs to be supremely robust in order to meet the most rigorous standards in terms of reliability.
This project saw IMI Critical Engineering’s IMI CCI business tasked with providing a series of bespoke high-pressure choke valves. Choke valves are widely used in the sector to control the rate of flow of liquids and gases. Each valve had to be able to handle multi-phase flow with entrained solids, which can accelerate the rate of erosion. The valves needed to be reliable with long service life and requiring minimal maintenance. In order to size the valve equipment correctly, engineers at IMI CCI had to account for multiple system dynamic factors. Two custom valve designs were provided; an 8 and 6 in. 11000 API with solid tungsten carbide trim, capable of withstanding a 2400 psi drop in pressure.
Taking the site-specific requirement for lower late life pressures into account, IMI’s patented DRAG© multi-stage trim technology incorporated windows into the top of the disk stack, thereby limiting the trim exit velocity to a safe level, irrespective of the pressure drop. After three years of service, the valves underwent a scheduled maintenance outage. Although initial inspection found the valves to have a significant amount of black debris and several clogged ports, it was found that the trim was as good as new and that the debris was from initial well flow material and did not affect the valves’ performance.