Method and apparatus for permanent measurement of wellbore formation pressure from an in-situ cemented location

An in-situ wellbore formation pressure gauge system for determination of a wellbore formation pressure of a formation fluid through a layer of cement, said pressure gauge system comprising:

• a housing arranged to be permanently installed in said cement on the outside of a wellbore casing, wherein said housing comprises:
• a pressure sensor with an output pressure signal (6s);
• a first oil filled chamber;
• a pressure transfer means between said first oil filled chamber and said pressure sensor, arranged to isolate said pressure sensor from said oil filled chamber;
• and
• a pressure permeable filter port through a wall of said housing, wherein said pressure permeable filter port is in hydrostatic connectivity with said first oil filled chamber,
• wherein said pressure gauge system further comprises a porous string extending outside said housing from said filter port, wherein said string has a higher porosity and a higher hydrostatic connectivity than said cement for said formation fluid, and wherein said string is arranged for transferring said formation fluid in its longitudinal direction when it is embedded in said cement to allow said formation pressure to act on said pressure transfer means via hydrostatic connectivity in said cement and in said string.