METHODS AND SYSTEMS FOR DETERMINING RESERVOIR PROPERTIES OF SUBTERRANEAN FORMATIONS WITH PRE-EXISTING FRACTURES

摘要

Methods and systems are provided for evaluating subsurface earth oil and gasformations. More particularly, methods and systems are provided fordetermining reservoir properties such as reservoir transmissibilities andaverage reservoir pressures of formation layer(s) using quantitativerefracture-candidate diagnostic methods. The methods herein may use pressurefalloff data from the introduction of an injection fluid at a pressure abovethe formation fracture pressure to analyze reservoir properties. The modelrecognizes that a new induced fracture creates additional storage volume inthe formation and that a quantitative refracture-candidate diagnostic test ina layer may exhibit variable storage during the pressure falloff, and a changein storage may be observed at hydraulic fracture closure. From the estimatedformation properties, the methods may be useful for, among other things,determining whether a pre-existing fracture is damaged and evaluating theeffectiveness of a previous fracturing treatment to determine whether aformation requires restimulation.