Methods and systems are provided for evaluating subsurface earth oil and
gas formations. More particularly, methods and systems are provided for
determining reservoir properties such as reservoir transmissibilities and
average reservoir pressures of formation layer(s) using quantitative
refracture-candidate diagnostic methods. The methods herein may use
pressure falloff data from the introduction of an injection fluid at a
pressure above the formation fracture pressure to analyze reservoir
properties. The model recognizes that a new induced fracture creates
additional storage volume in the formation and that a quantitative
refracture-candidate diagnostic test in a layer may exhibit variable
storage during the pressure falloff, and a change in storage may be
observed at hydraulic fracture closure. From the estimated formation
properties, the methods may be useful for, among other things,
determining whether a pre-existing fracture is damaged and evaluating the
effectiveness of a previous fracturing treatment to determine whether a
formation requires restimulation.