A casing centraliser and assembly comprising a tubular and a centraliser, the centraliser comprising a plastics material.

A tubular centralizer is secured to the tubular for run in.

The polymeric centralizer is non-sparking for use in hazardous environments, abrasion and wear resistant, and provides protection from electrolysis between adjacent casing strings.

The open-ended nature of the centraliser (2) allows cement to pass through the centraliser (2).

A centralizer including hollow structural components.

A projecting element for use in the centraliser, and a method of selecting and assembling a centraliser are also provided.

The centring device is formed by a flow drilling operation.

A centralizer for centralizing a tubular in a wellbore, and a method of manufacturing a centralizer.

In another embodiment, the bands (12A, 12B) are secured to the centralizer (10) to prevent separation of the ruptured bands (12A', 12B') from the deployed centralizer (10').

The stop collar can also include centralizer blades coupled directly thereto, instead of welding the centralizer blades to the production tubular.

In the transverse part of the tube (24) which comprises the centring device, the tube (24) has a cross section elongated in the direction of the axis of the hole in the centring device.

The invention is providing a junction fastener which is self-supporting and self-centering.

Apparatus for centralising a casing comprises a centraliser (10), for example, a bow centraliser, having a plurality of spring bows (24) connecting to spaced end collars (20).

On curing the centralizer (100) is firmly secured to the tubular.

A centralizer (100) including hollow structural components (110) .