Formation Strength Tests Calculations

This article presents the following Formation Strength Tests Calculations:

- Formation Intake Gradient (FIG)

- Effective Mud Gradient (EMG)

- Maximum Allowable Annular Surface Pressure (MAASP)


Formation strength testing

Limit or leak-off tests in development wells may be omitted if no hydrocarbon bearing and/or overpressured formations are to be penetrated. Information obtained from leak-off tests in straight holes…

FST Procedure

This article presents Formation Strength Tests Equipment and Procedure.

Equipment Requirements

A formation strength test requires:

  • a Cement Pump with mud tank calibrated in ¼ bbl
  • calibrated gauges…

Formation Strength Tests Profiles and Definitions

Formation strength tests (FST’s - sometimes referred to as “leak-off tests” (L.O.T) or “limit tests” or “formation intake tests” (F.I.T)) measure the formation strength below the casing. FST’s, shall…