The role of faults and natural fractures on hydraulic fracture stimulation in the Vaca Muerta Play, of the Neuquén basin, Argentina, is investigated using a 3D, fully coupled, fracture and fluid flow simulator. During the development of the Vaca Muerta Shale, and due to the complex nature of the geology and geomechanical conditions of the play, well interference has been observed while pumping a vertical well. Microseismic events recorded during stimulation show a map-view “Z” pattern that has not been observed before and potentially identifies a trend of preexisting natural fractures/faults striking NE-SW and NW-SW, and steeply dipping that could hydraulically connect adjacent wells. We used a 3D coupled flow and geomechanical simulator to evaluate the geometric characteristics and material and fault properties that could produce well interference using the field parameters utilized during the stimulation operations in the study pad, and that would produce comparable synthetic microseismicity. Simulation results show that fluid pressure can communicate through sufficiently conductive faults for relatively long distances between 300 m and 700 m. In the case investigated here, hydraulic fractures can be arrested by faults and reinitiate from its tip. Fracture height growth exceeds the estimated propped height, consistent with the distribution of microseismicity. Results also indicate that the microseismic event cloud distribution follows large-scale structures, and therefore the presence of conductive faults could explain the well interference problems observed in the field.

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