Real-time water detection and flow rate tracking in vertical and deviated intelligent wells with pressure sensors

Value addition via real-time reservoir monitoring and optimisation is one of the main drivers for the increasing implementation of intelligent (I-)well completions. The benefits from these more expensive Completions will be realized through increased reserves generated by increased drainage efficiency and reduction in well numbers and intervention frequency. A more rigorous exploitation of the real time production data is necessary to fully achieve this objective. We previously showed that water influx time and source could be detected in horizontal wells in real time'. Extension of this technique will be shown to allow confident detection of water influx in vertical or deviated, multi-zone andlor multi-lateral I- well completions. The source of water influx into the well and the zonal fluid contribution will be quantified, allowing this unwanted fluid's production to be reduced. Knowledge of the influx time and source permits both production optimisation and improved reservoir sweep efficiency; processes that increase the well's productive life and reserves. It will be demonstrated that monitoring of the pressure drop, called dP trending in this paper, across multiple pressure sensors correctly located within a multi-zone vertical or deviated I-completion can identify the time and location of the water influx into the well. We will discuss the necessary conditions to ensure clear identification of these parameters. The concept of "Normalised Pressure Drop Signatures will be introduced. It has proven to be particularly valuable for water influx detection and zonal flow rate monitoring purposes. The concept will be tested with data generated from a synthetic model of a 4-zone, deviated, I-well completion and with real- field data from an instrumented North Sea well. Copyright 2008, Society of Petroleum Engineers.