A new type of wireline-powered debris removal system that efficiently captures and retains a wide variety of wellbore debris types is presented. The system's unique benefits and performance are demonstrated through modeling and testing in controlled conditions.
Wireline-powered debris removal technology uses localized fluid circulation generated downhole to vacuum debris into bailers for capture. Challenges with conventional systems are related to the ability to continuously mobilize and separate a variety of debris including fine particulates and cohesive debris-binder mixtures. The new wireline debris removal system improves on previous technology by addressing the specific challenges of each of the debris types. This performance improvement is enabled by using a progressing cavity pump (PCP) to create powerful bidirectional suction pressure and a staged bailer configuration with parallel flow filters for maximum fill efficiency.
Pump performance is compared analytically for a centrifugal pump and a PCP to demonstrate the benefits of the PCP for debris collection applications. These benefits include reverse pumping ability for unsticking the toolstring when operating in debris-filled wellbores. This pump analysis defines a suction pressure budget, which is used to analyze the performance and capabilities of the staged bailer system. The pressure losses and debris accumulation profile of the new top-fed parallel flow filter bailers is determined by using fluid dynamics models. Results of an extensive testing campaign are presented to validate model results. Actual collection performance is presented for a wide variety of debris types using the new debris removal system.
The new wireline debris removal system's use of a PCP to generate the necessary vacuum and provide bidirectional capabilities for operational flexibility in combination with maximum debris recovery provided by staged bailers with parallel flow filters will bring new efficiencies and reliability to intervention operations.