This topic will demonstrate you how to determine accumulator bottles required for Koomey Unit (Accumulator Unit) in order to close the surface BOP stack.
This is a specification of Accumulator (Koomey) Unit.
Accumulator 3,000 psi system
Volume each bottle is 10 gallon.
Pre charge pressure is 1,000 psi.
Minimum operating pressure is 1,200 psi (200 psi over pre charge pressure)
Usable fluid per gallon is 5 gallon.
Safety factor require is 50 %. This safety factor may be different depending on each company’s requirement.
BOP Stack and HCR’s as listed below:
| Equipment | Gallon to open | Gallon to close |
| Annular Preventor | 4.0 | 4.5 |
| Upper Pipe Rams | 3.0 | 3.5 |
| Blind Shear Rams | 3.5 | 4.0 |
| Lower Pipe Rams | 3.0 | 3.5 |
| Choke HCR | 0.5 | 0.5 |
| Kill HCR | 0.5 | 0.5 |
