• Overview
The WellTools Hydraulic Under-Reamer is designed to clean or remove cement or scale from the inside diameter of down-hole tubulars. The tool is RIH in the collapsed position and once the desired depth is reached increasing the pump-rate through the tool expands the blades to the correct diameter. Once the blades are fully expanded the set down weight required for milling will keep the blades locked open.
Once the clean-out job has been completed reducing the pump-rate allows the tool to pull the blades back into the body.
• Design Features
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Positive blade retraction and expansion; this allows pumping at a reduced rate whilst running in hole. |
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Tool design allows reaming in either direction. |
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Blades mechanically locked open as long as milling weight is maintained. |
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Fluid can be directed onto each blade through inter-changeable nozzles to ensure positive flushing action. |
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Blades are linked together preventing independent movement which detracts from the clean-out performance of the tool. |
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Pressure retaining fluid path through the tool to additional stages and through to the bit. |
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Blades can be supplied dressed with any of the conventional cutting matrixes depending upon scale or cement properties. |
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Two stage tool gives increased cutting surface and improved stabilisation. |
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Tool can be dressed with Anchor blades to assist during tubing cutting operations. |
| Tool OD |
Connections |
Max Tubing /
Casing Size |
Tensile Yield |
Torsional Yield |
| Ø2.125" |
1-1/2" AMMT Box & Pin |
Ø5.000" |
80,000 lbs |
1,400 ft-lbs |
| Ø2.875" |
2-3/8" PAC DSI Box & Pin |
Ø7.000" |
126,000 lbs |
1,800 ft-lbs |
*other sizes available on request.
**only one stage is shown in the image. The UnderReamer is run as two identical stage, offset by 90°
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