Equalising v Non-Equalising Tubing Retrievable Safety Valves on Subsea Oil Projects
04 October 2016
We are planning on 6 x horizontal subsea oil production wells and 6 x water injection wells. The plan will be to run 5.5" TRSCSSV's with 7"x 5.5" tubing. The predicted production rates will range from 10-20bopd and typical THP 1900-3000psi. Life of the development is about 20years.
We would like to learn from other operators experience with either NE (Non equalising) or E (Self equalising) TRSCSSVs in similar subsea wells. Proposal is to run E in the oil and water developments to improve operability - but the concern is still there about reliability and survivability of E vs NE. Key to the decision is the long term survivability of the valve to help maximise the up time of the wells. Plan is for no intervention.
1. What TRSCSSV's do you prefer to install (NE vs E) in subsea GAS and OIL wells. What is the reasoning behind this decision? Ours is an oil development.
2. What experiences are you have with either NE or E valves in similar, or otherwise relevant situations.
3. Our wells are predominantly oil wells for this development, so I'd particularly appreciate your experiences on oil developments.