Downhole fiber optic measurement of packers during fluid injection operations

An embodiment of a system for performing a downhole operation includes a carrier having an isolation assembly including at least one packer having a deformable element configured to isolate a section of a borehole in the earth formation, and an injection assembly configured to inject a fluid into the isolated section and pressurize the isolated section. The system also includes a measurement assembly including an interrogation unit coupled to at least one optical fiber having a length disposed at the deformable element that includes a plurality of measurement locations, and a processor configured to receive signals reflected by the plurality of measurement locations in real time during the downhole operation, calculate an amount of deformation of the deformable packer element, and estimate at least one property of the formation based on the deformation, the at least one property including a strain of the formation in response to injection of fluid.