Running Liners with CRT Flashcards
(28 cards)
When is a hydraulic Liner Hanger normally used?
A hydraulic Liner Hanger is normally used when the wellbore trajectory is deviated or horizontal and the use of mechanical liner is not reliable.
What are Pocketed slips good for?
Pocketed slips are good for High Torque Drill Down applications. They protect the slips when the liner is rotated to overcome tight spots and restrictions.
What is the advantage of having Liners equipped with Rotational bearings?
Bearings enable the Liner to be rotated after the Liner Hanger is set and during cementation.
What is the purpose of a Liner Top Packer?
To provide annular seal between the casing and the liner.
How is the CRT Running Tool released from the Liner?
The CRT Running Tool is released from the Liner Hanger by pressure actuation.
At what point is the CRT actuation pressure set during a Liner Operation?
The hydraulic actuation pressure of the CRT is typically set to be between the Liner Hanger actuation pressure and the Ball Seat actuation pressure with sufficient margin in between them, 500psi at least.
Can the CRT be released from the Liner Hanger in tension?
No, the CRT needs to be in compression and pressure applied to actuate the hydraulic cylinder and retract the collet.
When is the Running Tool released from the Liner Hanger?
The CRT Running Tool is released when the Liner Hanger is fully set and supporting the entire weight of the Liner system.
What happens if the CRT is in tension during the release attempt?
The Tool will not release, because the collet will not retract until compression is applied and the hydraulic fully shifts to retract the collet from the profile in the packer body.
What is the purpose of the Torque Sleeve in the CRT?
The Torque sleeve in the CRT is part of the Clutch Mechanism, it is designed to transmit torque in tension and compression to a matching profile on the packer body.
When is the Clutch mechanism at the bottom of the Torque Sleeve useful?
It is particularly useful in deviated wellbores when there is a need to rotate the system in order to get the Liner to the Target Depth.
How does the Secondary Mechanical Release of the CRT work?
The Secondary Release mechanism works in 2 steps: ¼ turn to the left and then compression. 2 sets of shear screws involved.
How should the torsional shear set screws be pinned?
It should be pinned in such a way that when the torque is applied to get the ¼ turn rotation at the bottom, no connections above the tool are broken or the liner itself must not rotate.
What precautions must be taken? (For secondary release)
It is important to ensure that there is enough left hand torque resistance at the Liner to allow the torsional shear to be actuated.
What other factors should be considered?
Left hand torque requirements should be considered for all possible scenarios: One where the Hanger is set and the other where the Hanger is possibly set on bottom.
When is the Anti-Left Hand Rotation feature important?
It is important when running short liners, relatively straight wells, drill down applications and low torsional drag applications.
Does Backlash affect the Torsional Shear screws?
Yes, it does; the shear screws have to withstand its effects.
What is backlash?
Backlash occurs when rotating a landing string and allowing it to unwind quickly, or in high torque drill down applications when the Liner breaks through.
What is the function of the axial shear?
A safeguard against accidental release in case of backlash during drill down applications.
How is the axial shear actuated?
It is actuated by slacking off a predetermined weight while the CRT is biased with Left Hand Torsion.
What is a rule of thumb when pinning the axial shear?
The rule of thumb is to pin the axial shear to a value that is slightly less than the minimum packer setting force.
What if the Ball Seat blows prematurely?
It has an optional standing valve seat that accepts a standing valve run in hole with slick line.
Can you set the Hydraulic Liner Hanger with the standing valve?
No, with the Standing Valve in place, you can release the CRT but not set the Liner Hanger.
Can the standing valve be pulled out?
Yes, with Slick-line or Wireline.
