Standpipe Pressure (SPP)
Definition - What does Standpipe Pressure (SPP) mean?
Standpipe pressure (SPP) is the total pressure loss in a system that occurs due to fluid friction. It is the summation of pressure loss in annulus, pressure loss in drill string, pressure loss in bottom hole assembly (BHA) and pressure loss across the bit. Thus, we can write
SPP = Annulus pressure loss + Drill string pressure loss + BHA pressure loss + pressure loss across the drill bit
Petropedia explains Standpipe Pressure (SPP)
Standpipe pressure (SPP) is one of the important parameters that must be known when drilling a well in order to select the required jet bit nozzle size, determine the effective flow rate of the cleaning fluid to ensure efficient cleaning of a drilled hole and select a proper mud pump liner. Regular monitoring of SPP also helps to determine downhole problems and inefficiencies such as avoiding too low SPPs and keeping too high SPPs.
Keeping the SPP too low results in a washed out bit nozzle and the chances of breaking down drill string increases. The pump packing can also crack and make joints loose. Conversely, keeping the SPP too high during drilling can result in increased mud density and viscosity. There are various rheological models that are used to determine the effective standpipe pressure in a wellbore during drilling. They are:
- Newtonian model
- Bingham plastic model
- Power law model and
- Herschel Bulkley model