Proof of Function of a BOP Stack

What are the Proofs of Function for a Surface Stack?

Here are the Proofs of Function of a Surface Stack:

1. 1. Regulated Control Fluid Pressure: The regulated control fluid pressure will decrease and then return to its previously set pressure.
   2. Accumulator Pressure: The accumulator pressure will drop and subsequently return to its normal pressure, although it may not reach normal levels until the pressure drops to the point where the charge pumps are activated.
   3. Flow Meter Reading: If the panel is equipped with a flow meter, the volume of fluid used to perform the function should be consistent with the preventer in use. (All subsea rig floor panels must have a resettable flow meter that tracks the total volume used to operate a subsea function.)
   4. Function Lights: The light for the active function will illuminate, while the light for the opposite function will go out. Although this is not a proof of function, it does confirm that the three-position valve on the closing unit has been moved.
   
   

   What are the Proofs of Function for a Subsea Stack?

   Primary Positive Indication:

   The manifold or annular pressure (depending on the specific function) drops and then returns to its normal regulated pressure. This is the primary indication that the function has occurred.

Secondary Positive Indications:

1. The accumulator pressure drops and eventually returns to normal, though it may take longer to stabilize.
2. The volume of fluid used is consistent with the equipment being operated.
3. The light on the driller’s remote panel, while not a definitive proof of function, can serve as supplementary evidence when considered alongside the primary and secondary positive indicators.


For further reading on this or any other well control subject, consult my Well Control Manual at: https://learn-well-control.com/product/well-control-manual-by-edwin-ritchie/