Bandurria Sur: Characterization, Detection, and Mitigation of Influxes and Losses in the Quintuco Formation for the Drilling of Horizontal Wells in the Vaca Muerta Formation

Abstract The Vaca Muerta Formation (Weaver, 1931) is the main hydrocarbon-generating unit of the Neuquén Basin and is currently developed as an unconventional resource through horizontal wells. The Bandurria Sur (BS) field, located in the eastern sector of the Neuquén Basin, contains more than 230 horizontal wells producing oil from different levels of the Vaca Muerta Formation. During the drilling of these wells, various operational problems have been recorded when crossing the Quintuco Formation, mainly gas influxes and losses, which have led to well abandonment or significant delays in stabilizing drilling operations. The main objective of this work is to determine whether these events (influxes/losses) that generate these operational issues are concentrated in a specific zone or layer of the Quintuco Formation, or whether their occurrence is random. To this end, an integrated study was carried out that includes geological, seismic, petrophysical, and geomechanical characterization to understand the architecture of the formation and its properties. Preliminary results are presented that identify critical intervals and their relationship with facies, fracturing, and operational conditions.