Fully Retrievable ESP: A New Artificial Lift Concept

The “Fully Retrievable” ESP System is a new technology, which permits the rigless deployment and retrieve of conventional Electrical Submersible Pump (ESP): a wire-line, coil-tubing or rod should perform these actions. This paper shows the eni experiences in this application and the approach used for the completion design according with the company policy highlighting the benefits and the criticalities faced. Two Fully Retrievable ESP were installed by eni in the following fields:  Alaska - OP18-08 - Nikaitchuq Field - onshore arctic environment  Congo - FOKM 101 - Foukanda field - offshore. Each of them involved different issues and will be discussed in detail in the following sections. This paper goes all the way through the well definition, completion philosophy and ESP system selection exploring constraints and limitation of this equipment. An economical comparison was performed and the conclusion is that the retrievable ESP should be used in all of those fields where the workover cost is high and the deferred production is important due to rig unavailability. It will be presented that the main benefits of this technology include:  Simple ESP retrieving with smaller environmental impact  Capability to run temporary systems to clean up or test the well  Fine tuning of the ESP based on production data. The benefits of the technology were tested using an internal eni tools for risk analysis based on Monte Carlo simulation: the results are discussed in the last part of the article and highlighted the above expressed consideration and main criticalities.