WEA Inner String Hero 1920X1080
WEA Inner String Hero 1920X1080

Inner-string packer

Maintaining well integrity and preventing fluid or gas migration

Inner-string packer

  • Applications
    Inner-string packer
The primary function of an inner-string packer is to create a reliable and high-integrity seal between the base pipe OD and the host casing ID. This seal is vital for maintaining well integrity and preventing fluid or gas migration between different sections of the wellbore.

Anchoring capability

In addition to the sealing function, inner-string packers might incorporate opposing slips which act as an anchor. The slips are designed to engage with the inner surface of the host casing, providing mechanical support and preventing movement of the base pipe. This anchoring capability is vital in applications where axial or rotational forces may be encountered, such as during well stimulation or production operations.

Case highlight

A National Oil Company (NOC) in the Middle East had designed and planned a 12-zone smart completion and required a reliable anchor for the toe section. Whilst the client had previous experience with alternative hydraulically-set production packers...

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Welltec® Expandable Anchor (WEA) for Inner-String packer

The design of the WEA for Inner-String Packer minimizes subcomponents, ensuring reliability and efficiency while simplifying well construction. The WEA enables reciprocation, circulation, and/or rotation during deployment. 

Welltec® Expandable Anchor (WEA) for Inner-String Packer

Versatile and compatible technology

The Welltec Expandable Anchor (WEA) for Inner-String Packer is run in combination with a Metal Expandable Packer (MEP), i.e., a proven hydraulic expansion sleeve.

The rapid application of surface-controlled pressure simultaneously expands the WEA and the MEP system, offering an efficient alternative to conventional inner-string solutions. The expansion sleeve hydraulically expands the bidirectional anchors, which uniformly engage with the ID of the outer casing. Increased loading/anchoring capacity is achieved via the modular addition of WEA sleeves.


The system is compatible with many casing internal diameters and feedthrough lines. Its slim running OD provides a solution in scenarios where casing ID restrictions prevent deployment of conventional packers – the WEA solution also eliminates the requirement for a de-burr run when deployed within the perforated tubing.

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