For years downhole monitoring and control have been widely used technologies to improve production and reservoir management. At the same time drilling technology has evolved and resulted in a rise of deep and complex multi-lateral wells. A well path may cover multiple production zones and connectivity between, and performance of production zones are often difficult to quantify. These challenges have contributed to a growing demand for information and control directly at the reservoir. This paper will show a reliable method to bridge the gap between the upper and lower completion for both control and data flow.
The method is a combination of two well proven systems, namely a cabled permanent downhole monitoring system that is connected to the surface with a tubing encapsulated conductor and instrumentation and control tools that are placed in the production zones of the laterals and are operated wirelessly. Extending the capabilities of both systems, a new wireless interface incorporated at the lower end of the cabled monitoring system enables duplex communication with the wireless instruments and tools in the lower completion. Communication between the wired system and wireless operated instruments may be based on acoustic or electromagnetic signals.
The combination of the two technologies provides an innovative new method to overcome the challenge of making a physical connection between the upper and lower completion for monitoring and control data transmission and may also be adapted to access instrumentation and controls in multiple laterals. The adaption of the technology is straightforward as the standard interface card is placed in a surface acquisition unit for dry trees and in the subsea control modules for wet trees. The interface card can send commands and log data from both the wired instrumentation in the upper completion and the wireless operated instruments and controls in the lower completion.