Navigating the Depths: How High-Force Tractors Enable Access to Deep Reservoirs

Abstract High-force wireline tractors address the conveyance challenges of ultradeep reservoirs with complex trajectories, enabling access to deep reservoirs. Accessing ultradeep wells for surveillance and intervention is highly challenging with conventional methods. Conveying long downhole tools through complex trajectories in ultradeep wells demands extreme conveyance forces, compounded by power delivery limitations associated with long cables. In this paper we provide an overview of these challenges faced by an operator in the United Arab Emirates (UAE) and a novel wireline tractor solution that overcomes these challenges to access ultradeep reservoirs with increased efficiency and reliability. The approach consists of analyzing conveyance challenges and deploying an innovative technological solution using high-force tractors to enable reliable data acquisition in deep reservoirs. The following methods are used: Model and analyze well tortuosity to estimate tractor forces and navigation challenges.Select a high-force tractor system with a bespoke motor design for the job.Choose an efficient telemetry system for reliable communication with downhole tools.Design a purpose-fit tool configuration and operation strategy to navigate complex completions.Conduct surface integration tests to assess tool capability and reliability.Provide feedback to enhance tool design and performance at the product manufacturing center. The new high-force tractor design delivers a remarkable 70% increase in conveyance force compared to legacy tractors, as demonstrated in a surface integration test (SIT). Additionally, it achieves twice the tractoring speed under higher loads, enhancing operational efficiency and reducing intervention time. The implementation of an advanced high-speed telemetry system enables reliable surface acquisition of downhole sensor data across extended cable lengths while tractoring, maintaining a high signal-to-noise ratio. This new tractor system was successfully deployed in seven wells to access deep reservoirs for an operator in UAE. This system was first deployed to convey production logging tools in the main bore of a trilateral well with 18-ft long sidetrack windows. By combining increased force and efficiency, the tractors successfully navigated through these challenging sidetrack windows. Key achievements include secure access to reservoirs via multiple passes across sidetrack windows; a cumulative tractoring distance of more than 27,000 ft in the first well; reliable acquisition of downhole tool data over a 43,500-ft-long wireline cable using the new telemetry system; simultaneous acquisition of production log data during tractoring, which ensures high-quality data and improved operational efficiency; and accurate quantification of horizontal lateral zonal contributions from all three laterals. This successful deployment of high-force tractors opens opportunities for accessing ultradeep reservoirs.