Revolutionizing Reservoir Access: The World's First Capstan Conveyance with Polymer-Locked Cable and High-Force Tractor

Accessing ultradeep reservoirs for surveillance and intervention poses significant challenges when using conventional methods. Navigating complex trajectories with long downhole tool assemblies in ultradeep wells requires considerable conveyance forces and extreme wireline surface tensions that surpass the capacity of standard wireline logging units. This paper addresses the conveyance challenges encountered by an operator in the United Arab Emirates (UAE) and outlines an innovative combination of solutions that significantly enhance wireline accessibility to unprecedented depths. The approach involves overcoming conveyance challenges using a polymer-locked cable, dual-drum capstan, and high-force tractors. This ensures safe access and retrieval of the bottomhole assembly (BHA) without damaging the cable while acquiring reliable data in deep reservoirs. The methods employed include: Analyzing well tortuosity to estimate surface tensions and conveyance forces.Selecting a conveyance solution that combines polymer-locked cable, high-force tractor, and dual-drum capstan.Testing cable friction with the capstan.Training wireline crew on capstan setup and operation for production logging.Performing surface integration tests to evaluate pulling capacity, speed, and surface friction.Conducting risk assessments and implementing control measures. The innovative integration of conveyance solutions enabled access to an unprecedented depth of 37,725 ft within an ultradeep horizontal well. Employing the capstan mitigated the risk of excessive cable tension at the cable drum, thereby preventing potential damage to both the cable and the drum. This conveyance methodology enabled the operator to fully access the well and obtain production logging data efficiently. This marks the first deployment of a polymer-locked cable using a dual-drum capstan and high-force tractor. It represents the world's deepest tractor conveyance using capstan technology. The success of this deployment demonstrates how innovative technology can address and overcome conveyance challenges associated with conventional methods, thus enabling reliable access to ultradeep reservoirs. It allows operators to extend wireline intervention to reach long horizontal wells up to 40,000 ft measured depth (MD) and beyond.