The Modular Downhole Tractor (MDT) is a wireline deployed system used to push passenger logging tools and perforating guns into difficult well profiles. The MDT contains a highly efficient (97%) and powerful electric motor that drives the tool. Signals from the MDT and associated sensors are compressed downhole in the electronics cartridge for transmitting to surface enabling the logging engineer to monitor various parameters in real-time and to control the MDT with precision. A surface-controlled switch, within the electronics cartridge, isolates the MDT from its passenger tools.
The MDT drive arm and wheels are optimized to provide the maximum force to drive the MDT/passenger tool combination along the well. They open when power is applied to the clutch and close when it is switched off. A fail-safe mechanism automatically disengages the clutch if power is lost, completely closing the drive arms, so the MDT can safely be retrieved. The arms are available in various sizes to match the casing internal diameter. In complex completions each pair of arms can be of different lengths to suit casings of different sizes.
Knuckle Joints and low friction roller centralizers specifically designed to operate with the MDT can be included in the tool configuration to aid access in difficult areas of the well. CCL and head tension readings are provided with the MDT; They are used for depth control and over-pull indication respectively. In addition, tractor load, wheel speed, and arm position are monitored, all of which provide the user with clear indications of what is happening downhole.
The software is used to plan MDT operations. The software can be used to identify many operational considerations such as optimum MDT configuration, the depth at which the MDT should be activated and to plot tractor and cable tension forces.
Features
Real-time log of CCL, Head Tension, Tractor Load, Tractor Speed, and Arm Position.
DC powered Tractor drives both uphole and downhole.
Modular drive sections.
WEST simulation software for pre-job planning.
Helicopter transportable.
Low cost alternative to coil tubing deployment.
