Formation Fracture Pressure
Definition - What does Formation Fracture Pressure mean?
Formation Fracture Pressure is the pressure required to rupture a formation, in order to make whole mud flow into it. The symbol PFB is used to denote this pressure and expressed as pressure gradient GFB by unit psi/foot. This pressure is also known as formation breakdown pressure. The pressure is commonly discovered in the formations just below the casing shoe by conducting a leak-off test. The test is used to test the formation strength and is also called formation integrity test. The FIT comes into effect after running and cementing the casing in place.
Petropedia explains Formation Fracture Pressure
Formation Fracture Pressure is used to make injection fluids to hydraulically cause fractures in a rock formation. The pressure is tested using FIT which allows the testing of the formation even after minimum damage and disturbance as a result of ongoing drilling. It also provides a clear indication of strength that has to be detected for one separated zone. The pressure is applied in a wellbore and the pumping pressure and rate are increased. After the pumping pressure is increased, it reaches a meeting point where the pressure drops and that point is formation integrity test pressure.