1. n. [Drilling Fluids]

A test to measure static filtration behavior of water mud or oil mud at elevated temperature, up to about 380 degF [193 degC], maximum 450 degF [227 degC] if a special cell is used), usually according to the specifications of API. Although the test can simulate downhole temperature conditions, it does not simulate downhole pressure. Total pressure in a cell should not exceed 700 psi [4,900 kPa], and the differential pressure across the filter medium is specified as 500 psi [3,500 kPa]. Because these cells are half the size of the ambient filtration area, HPHT filtrate volumes after 30 minutes are doubled.

Synonyms: static filter press

Antonyms: low-pressure, low-temperature filtration test

Alternate Form: HPHT filtration test

See: electrical stability test,  filtercake,  filter press,  filter-cake thickness,  filtrate volume,  fluid-loss control,  fluid-loss-control material,  geothermal gradient,  high-pressure, high-temperature,  jar test,  particle-plugging apparatus,  sintered