Abstract
Monitoring fluid saturation and reservoir surveillance are essential techniques for effective reservoir management. As reservoirs age and water sweep advances, it becomes more difficult to find infill well placements. Reservoir scale saturation surveillance technologies offer a novel and promising way to optimise hydrocarbon recovery through development decisions. In addition, it can help evaluate sweep efficiency and improve reservoir simulation models. There are currently various proven electromagnetism approaches for reservoir scale saturation monitoring, including cross-well-EM (X-well-EM), Surface to Borehole EM (STB-EM), Borehole to Surface EM (BTS-EM), and EM through the casing. This study will examine all EM technologies.
Each technology has unique benefits and drawbacks that determine its field applications and objectives. The X-well-EM technology offers a cross-sectional resistivity profile at the inter-well level, which may be used to map oil zones that have been bypassed. Similar to the surface to borehole and borehole to surface technologies, the surface to borehole and borehole to surface technologies detect resistivity changes between transmitters and receivers for the same purpose. The benefit of these technologies is that they may be utilised for both one-time and recurring surveys. This feature permits the implementation of a feasible flood monitoring system throughout the field's lifetime.
This paper will thoroughly discuss the design for each technology and the survey planning. In addition, the challenges and critical criteria for conducting a successful survey will be discussed, including measurement accuracy, inter-well spacing, depth, signal-to-noise ratio, operating cost and time, completion kinds, and the optimal frequency range. Finally, we will present the end result that makes electromagnetism an intriguing concept emerging in the field of reservoir surveillance. Examining and contrasting the various EM survey approaches in order to highlight the best practice and its potential for field growth.
