Abstract
During the 1990’s, a battery-powered electro-mechanical downhole service tool used to set/retrieve various pressure containment devices in the wellbore was introduced to the industry. These electro-mechanical actuators are capable of generating high but controllable axial forces at the point of application without relying on surface mechanical manipulations or explosive devices. This capability eliminates most of the logistical special safety considerations inherent with explosive actuators. Since the self-powered tool is independent of the surface machinery, another advantage is that it is possible to reduce the surface footprint for more efficient logistical management.
The electro-mechanical service tools are compatible with conventional slickline intervention methods and provide a practical alternative for explosive and hydrostatic setting tools. (See Fig. 1). This tool has also added significant cased-hole functionality to slickline intervention methods. While the first generation of the electro-mechanical service tools met the majority of conditions needed in the 1990’s, their functionality could not meet some of the operating requirements needed by the deeper, higher pressure fields being produced today.
This paper will describe a new tool system that provides the advantages of the standard downhole power unit (DPU®) system but overcomes the temperature limitations imposed by the more demanding downhole environments in today’s oilfield. The control logic, power management, and power delivery methods used to develop a functional and reliable electro-mechanical actuator for high-temperature/high pressure applications will be discussed. Also outlined is the environmental test program representing real world conditions that was used to validate its reliability. Finally, case histories will be presented.
