Modelling of Parent Child Well Interactions

Abstract

Abstract We performed a modeling study calibrating a coupled "true" hydraulic fracturing and reservoir simulator to a complex set of observations from a parent-child well pad in the STACK play located in the Anadarko Basin area of Oklahoma. The model was constrained by sealed wellbore pressure monitoring, interference testing, pressure responses during frac hits, production data, and responses to chemical treatment. It was possible to match the full set of observations in a single, continuous simulation by calibrating the fracture toughness and leakoff, the permeability and relative permeability, a parameter related to proppant transport, and parameters related to a ‘fracture conductivity damage’ mechanism built into the simulator. The ‘fracture damage’ calculations mimic the reaction of frac fluid with the formation fluid as they mix in a hydraulic fracture during and after a frac hit. The interpretation of ‘fracture conductivity damage’ is corroborated by production impacts after frac hits, positive response to chemical mitigation treatments, and direct sampling of material from the wellbore. Because of the volume and quality of calibration data available, it is possible to constrain the key uncertainties of the model. It can now be used to design strategies to mitigate negative impacts from parent/child interactions.