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.

This case study describes the deployment of logging tools on tractor in challenging wellbore conditions in a tight gas field in the Sultanate of Oman. Challenging conditions are defined by a high static temperature of 175°C; high static reservoir pressure of 72 MPa; a long, 5700-m wellbore; openhole configuration; and horizontal well profile. One of the conventional ways of deploying the caliper measurement in horizontal wells is through drillpipe conveyance. Deployment through coiled tubing conveyance is another option; however, this was not available owing to extensive logistical requirements and the operation's complexity. A newly developed openhole tractor designed for the well's extreme conditions was used to efficiently convey the logging tools. Features that enabled successful tool conveyance included the highest tractor force available in the industry, 6-drive tandem wheels, real-time adjustment of the radial force to the tractor arms, and active traction control for improved maneuverability. Calipers were successfully conveyed with the wireline tractor in the 800-m horizontal section of the 5000-m-deep well. The logging job took only 12 hours versus the traditional 60 hours required to convey the same tools on drillpipe. In addition, the tractor conveyance minimized the risks associated with operating at high temperature because it significantly reduced the time of exposure of tools to extreme high temperatures approaching their maximum temperature ratings, hence ensuring top performance and reliability. The fivefold time reduction also helped with the well economics and minimized the overall operational risks associated with the logging operation. The recorded caliper data enabled proper evaluation of the hole conditions for selecting the best location for setting the swellable packers.