Novel Method of Water Management by Interpreting Downhole Monitoring Data for Horizontal Wells

Intelligent well system technology enables downhole monitoring and zonal fluid production control in real time. Many published papers describe temperature and pressure sensing and its phenomenological interpretation to detect the position of water or gas entries. But few attempts have been made to develop a comprehensive model for well control decisions to detect and solve the problems in advance before water or gas early breakthrough. This paper provides a theoretical study for the downhole monitoring data interpretation workflow to enhance oil recovery. A synthetic horizontal well model was built using a commercial and scientific simulator to calculate the time-varying pressure and flow rate profiles for a heterogeneous bottom water drive reservoir. Simulation results showed that there were signs of temperature and pressure change before early water or gas breakthrough happens. Based on downhole monitoring data, we proposed a set of quantifiable evaluation index system that reflecting the possibility of early water breakthrough. Fuzzy comprehensive evaluation method was used to level the possibility of water entry at different positions along a horizontal well-bore. Once the possibility of early water breakthrough reaches high level in one segment, flow rate in this segment can be modified by the control device in real time. The methods proposed here will help us to design permanent monitoring systems and set realistic expectation for predictive capability of intelligent well systems. The use will provide guidance for water management in horizontal wells and enhance oil recovery in heterogeneous reservoir.