Wireline Electromechanical Shifting Tool with Large Expansion Ratio and Fully Controllable High-Force Capability
New electromechanical anchoring and shifting mechanisms for a 2 1/8-in wireline shifting tool employ innovative linkage designs to enable passage through 2.2-in-diameter restrictions and deployment in casings up to 5.0-in. inner diameter. The anchoring system delivers 60,000-lbf force through the entire opening range, and the tool provides more than 16,000 lbf of linear actuation force to the pressure-activated shifter.
Using wireline shifting tools for sliding sleeves, pulling plugs, fishing, and other operations requiring high axial forces is becoming more common because the tools generate forces comparable with surface-controlled pipe-conveyed devices while offering excellent operational control and real-time feedback downhole. Because operations may include going through a small-diameter restriction before shifting in a larger borehole, tools must open to a large diameter, a property known as the expansion ratio. However, as the expansion ratio increases, the ability of conventional tools for generating large linear forces diminishes. New anchor and shifting designs feature large expansion ratios while preserving the ability to deliver large linear loads.
Solutions are presented to the numerous challenges of the design for a wireline toolstring typically including an anchor, linear actuator, and shifting tool. The anchoring system has the capability to apply constant radial force that is independent of the borehole size. As with all intervention tools, it cannot stick to the tubular and must be fail-safe and fully retractable within the tool outside diameter (OD) in case of a power loss, even in high-debris environments. Integrity of the tubular where the anchor is set must be maintained. The anchoring force must not be influenced by the axial push/pull force of the linear actuator. Self-centralization of the anchoring system is needed to eliminate the large bending forces that would otherwise occur from the linear actuator action. Both the anchor and shifting tool must have features that enable pulling them out of hole reliably, even through a restriction. Force and opening displacement sensors are important in giving real-time feedback of the state of the system. In combination with integrated firmware, this enables the system to react to events in the hundred-milliseconds range for effective, high-accuracy operations. Examples are presented for tool usage for specific applications.
The novel designs presented in this paper expand the operating envelope of mechanical services on wireline to operations in wells that were previously not serviceable by such tools. Wider application of wireline tools will lead to reduced operational time and bring an increased success rate and intervention
reliability on a lower cost conveyance platform.