Monitoring - Microhydraulic Fracturing

The test can be carried out in openhole (with the accompanying risks of sticking tools) or in cased and perforated situations where isolation is possible. Generally in cased and perforated sections, you can only reliably determine the minimum principal stress.
Rate and pressure are monitored during the injection.
Because of wellbore storage effects, it is desirable but not absolutely essential to have bottomhole pressure measurements.
The procedures are essentially the same as for Extended Leakoff testing with the exception that the fluid in the hole will often be completion brine, injection water or whatever, rather than mud.
Issues related to interpretation of the pressure records include"\:
Uncertainties in the maximum principal stress calculation can occur if the formation adjacent to the wellbore has failed. Basic elastic relationships for interpretation should be used with caution.
Classical theories need to be modified to account for the stress conditions around inclined or horizontal wells.
Classical interpretation in a vertical well is often done incorrectly, not properly accounting for poroelasticity. Don't forget that thermal effects may have also changed the in-situ stresses around the wellbore.
Precaution: When stresses are reported, particularly from drilling operations and formation integrity evaluations they can be breakdown pressure gradients (gradients of fracture initiation pressure) or fracture propagation pressure gradients and not necessarily the value of or gradient for the minimum principal stress.