Oliver Valvetek identifies new and emerging opportunities to supply higher pressure small-bore subsea valves, and recognizes the technical barriers that hinder most other valve suppliers.
The subsea oil and gas industry has been rapidly developing new technology to allow the development of ‘challenging fields’. These challenges are usually associated with high pressure, high temperature (HP/HT), and operation at great depths. Fields with pressures of 15,000psi (1034bar) were generally considered high pressure, however, new fields are now being discovered and developed for well bore production with working pressures of 20, 00 psi (1380 bar).
Oliver Valvetek had already successfully designed and qualified a 3/8” Nominal Bore 20,000 CWP needle valve for a High Pressure / High Temperature field development in the Gulf of Mexico. Utilising this specialist and field-proven history with Shell Appomattox, Oliver Valvetek successfully developed and tested a Dual and Tripe Gate valve assembly in accordance with API6A PR2F, API 17D and API 17G.
Work began in March 2021 to develop two valve types that were required for critical application of flow control and monitoring on the Trident 20K Intervention System – ½” Double Gate Valve and ½” Triple Gate Valve, both manufactured using Nickel Alloy 718 material.
Project technical specification requirement:
- High Pressure 20,000 psi
- High Temperature +150°C / +302°F
- Operating Depth 3:048m / 10,000 ft
Small bore gate valves are often used for chemical injection, venting flowlines and bypass lines, and these valves can be required in single isolate arrangements but also in double and triple or 3 valve assemblies.
Weight is a crucial factor for equipment being lifted and installed on the subsea. Using the very latest in elastic-plastic finite element software, valve designs have been optimised to produce the most compact small-bore valve to operate subsea at 20,000 psi high pressure. API technical reports provided the necessary guidance to our engineering team, and client, on analysis tools and design processes for HP/HT subsea equipment.
This resulted in a Double Gate Valve comprising of 2 x manual Gate Valves in one block, and a Triple Gate valve with a combination of both manual and hydraulic functions. The full valve designs were subject to numerous technical assessments as part of the API qualification, followed by strict design evaluations including; FMECA, Elastic-plastic analysis, Ratcheting Assessment, and Fatigue Assessment, all of which were reviewed and verified by nominated I3P’s such as the Bureau of Safety & Environmental Enforcement (BSEE).
Courtesy of Oliver Valvetek.