| Popis: |
Some of the most important aspects to consider during the design, construction and productive life of a well are the amount and nature of the risks associated with the conveyance of downhole instruments to acquire critical formation-evaluation data while the hole is open, and downhole toolstrings needed to monitor or service the well after installing the completion and production hardware. Wells with horizontal sections in excess of 5,000 ft present significant challenges to the existing well intervention methods and technologies; in particular, production-logging programs under high-production rates using downhole tractor conveyance have proven to be particularly difficult to plan and execute in these wells. This paper describes the extreme conditions offered by these long horizontal wells, the underlying physics that support modeling of mechanical and hydraulic lift forces, the hazards present when conducting logging operations under flowing conditions using wireline and downhole tractors, the relevant conveyance risk-reduction technologies and methods to successfully plan and execute these extreme operations. To demonstrate the operational merits and practical aspects of the methods and solutions presented, a case study based on a real operation is included. |
