Determining Hydraulic-Fracture Orientation and Height Using After- Fracture Borehole Acoustic Attributes in the Vaca Muerta Unconventional Reservoirs

摘要

As high-permeability reservoirs approach their last years of productivity, oil and gas production will likely come from lowpermeability formations, requiring hydraulic-fracture stimulation to be economically promising. This is the case in Argentina with the recent development of unconventional reservoirs targeting the Vaca Muerta shale play. The success of a hydraulic-fracture job depends on several factors, including the formation geology itself, the formation mechanical properties, field-stress regime (direction and magnitude), minimum horizontal stress contrast, and the transition from the simulation to the execution of the fracture job. Production companies need tools that help them determine how successfully the hydraulic fractures have optimized well production and field development. These tools should provide information about hydraulic-fracture conductivity, geometry, complexity, and orientation. This paper presents the application of time-lapse anisotropy analysis, using data from an acoustic scanning platform combined with a gyro, to obtain information such as the propped fracture height and the hydraulic-fracture orientation. This information is essential in planning horizontal wells when the well axis is to be transverse to the direction of the fractures. Application of the acoustic scanning platform technology as a fracture optimization tool in the Vaca Muerta shale play allows for a comprehensive evaluation of the hydraulic-fracture geometry, which can be combined with post-stimulation production results to provide direct impact in the well production and field development.