Can a packer be used with a borehole diameter of φ90?

If the borehole diameter is φ90, it may not be possible to use a packer.

Depending on the type of anchor, placing a packer over it causes the anchor body to,

It may be larger than the inner diameter of the outer casing.

In that case, it will be necessary to change the drill hole diameter to φ115.

In fact, it’s highly likely that all manufacturers will switch to φ115.