Abstract
This paper describes a new Intelligent Well Completion (IWC) configuration used in Brazilian pre-salt fields. It also presents the first application of this new design and the future benefits expected. The conventional IWC design used in Brazilian pre-salt areas comprises cased hole wells. The casing perforation is performed before installing the completion, which does not provide a separation between upper and lower completion. The production string is installed in a single run from its lower part to the tubing hanger and does not include a disconnection element to allow the upper completion retrieval. The new design adds a separated lower completion that can temporarily isolate the formation during the upper completion installation and heavy workover operations.
In the development of the new openhole IWC design some features have been considered critical: maximum flow area, minimum complexity, CAPEX reduction, improved well safety, flexibility with single zone completion configuration and compatibility with workover. The introduction of a lower completion system added some complexity to the wells, at the same time as it provides reservoir isolation during upper completion installation. Other benefits observed are the decrease of the wellbore size required to drill into the reservoir as an openhole completion is to be installed instead of a case hole. In instance, the use of one of the casings is not required anymore. The proposed alternative was initially applied in one well for qualification and was capable of delivering a dual zone completion where initially an openhole single zone completion was planned. The use IWC in this well was an important feature for reservoir management due to the significant difference between the injectivity of the zones completed. The new design proved to be a success in this initial application.
The new solution developed has set a new completion philosophy for pre-sal wells. Other benefits of using a lower completion in IWC is the ability of quickly isolating the reservoir, what is especially important when major fluid losses are expected during drilling and completion phases. One of the major benefits of this approach is the possibility of installing the lower completion using Managed Pressure Drilling (MPD) techniques.
