RIASSUNTO
Abstract
Traditional slickline work usually encompasses basic mechanical manipulation for downhole intervention work. In the recent past, a variety of battery-powered downhole tools have emerged in the market, providing additional deepwater solutions for the industry. These tools include the extended-reach downhole power unit and the smart release tool. The downhole electrical power unit is an electro-mechanical setting tool that uses a timer activation switch to begin the setting process for a variety of downhole tools. The smart release tool provides a timer-based mechanism to release the deployment wire from the downhole toolstring, eliminating the exposures associated with dropping a cutter in the event of a stuck tool. These tools can be conveyed on slickline for a variety of intervention solutions, including setting tubing plugs and packers, pulling subsea tree plugs, setting pressure gauges in tubing profiles, and providing a mechanical release in highly-deviated, extended-reach wellbores.
This paper discusses specific well-intervention case histories using the downhole electrical power unit and the smart release tool. In the first case history, the downhole electrical power unit was used to set a packer assembly during a safety-valve repair. The smart release tool was used to soft set memory pressure gauges in wells without functioning, permanent downhole gauges, eliminating the need for jar action that could damage the gauges. Adaptations were made to the existing tool designs to respond to the well-specific challenges.
These case histories demonstrate applications in which the electro-mechanical timer-activated tools have provided solutions for deepwater Gulf of Mexico well-intervention projects. The discussion includes lessons learned from previous project designs, development of operational best practices, and possible future applications to extend the role of slickline in deepwater operations. Applications may include the use of the downhole power unit to set packers and bridge plugs in conjunction with memory logging tools to correlate depth, as well as continued use of the smart release tool to minimize risks associated with downhole mechanical evaluation and memory data acquisition.
Introduction
Deepwater Gulf of Mexico has become a challenging environment for rigless well-intervention work, with extensive use of slickline, electric wireline, and coiled tubing. In situations where slickline can be used, it results in substantially lower costs compared with e-line. The development of electro-mechanical tools has expanded the application of slickline, even on high-profile deepwater wells. Expansion and adaptations to these tools have opened the doors for additional low-cost solutions to intervention challenges.
This paper introduces two novel applications of electro-mechanical tools: mitigating a mechanical safety valve issue by making adaptations to an electro-mechanical setting tool and acquiring downhole pressure data throught the use of soft-set pressure gauges. The tool design and pre-job planning focuses on critical job design steps leading up to an intervention, and the successful execution on location reaffirms the potential value of slickline in these situations. The following case histories show how the electro-mechanical tools were adapted for specific downhole conditions.