Downhole Valves : Oil and Gas Well Completions

A: 0.5–2 psi/minute equalization is the tell. That rate aligns with erosion or seat wear, not a control line failure that would drive the valve open immediately, and not thermal expansion which plateaus once temperature stabilizes.

A: 300 psi is often close to the operating margin between open and fail-safe close. Any action that increases drawdown or cycles the valve risks an unplanned shut-in that could exceed MAWP on restart.

A: ±1% gauge accuracy at 1,500 psi is already ±15 psi. A 220 psi delta screams instrumentation or setup error before touching factory-set internals that are usually locked and MOC-controlled.

A: Fire case assumes loss of control pressure and unstable upstream conditions. Any leakage defeats the entire safety function, regardless of how small it looks during steady-state testing.