Advancement in Wireline Tractor Design Reduces Operating Time and Improves Reliability

A newly developed wireline tractor (Fig. 1) is exhibiting positive effects for total operating time and reliability. Not only can it deploy a wide range of logging tools, well intervention tools, and explosives at a rate up to 100 ft/min (6,000 ft/hr) in horizontal or highly deviated wells, it has an efficient electro-mechanical design. Additionally, the tractor can run in wells up to 350°F and 25,000psi with full tractoring force.

Historically, wireline tractors were based on a lower efficient hydraulically powered design or additional electronics to invert voltages were necessary (Sheiretov 2016). Because of advancements in downhole-rated DC motors and electronics, it's possible to increase reliability while delivering more power with less parasitic losses (Fig. 2).Important design points for a tractor include:

• Efficient and robust electro-mechanical architecture

• Compatibility with single and multiconductor wirelines

• Controlled by a real-time telemetry system to log tractor and well data while tractoring

• Precise control and feedback of tractor speed, torque, and wheel normal force

• Combinable with a wireline release tool, swivel, casing collar locator (CCL), downhole tension, accelerometers, explosives safety device, and rollers

Figure 1

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New wireline tractor.

Figure 1

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New wireline tractor.

Figure 2

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DC voltage electromechanical drive system example.

Figure 2

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DC voltage electromechanical drive system example.

The CCL, downhole tension, and accelerometer measurements assist with efficient tractor operations. The wheel normal force should be adjustable to the tractor through restrictions and completion components.