The Torus Annular Blowout Preventer is well suited for a variety of drilling and well servicing applications. One of its greatest potential uses is in enhanced oil recovery projects (EOR).
The Torus is ideal for closing around tubing and the wire conduit of an electric submersible pump associated with EOR projects. While other blowout preventers employ packers with metal fingers (see photo below) covered by a small amount of elastomer material, the Torus packer is a donut shaped mass of elastomer reinforced by two steel rings. The Torus closes via direct hydraulic force, causing the packing element to form tightly around tubing and conduit. If a spiral wound steel jacket covering the wire is employed, a minimal leak can be expected. In neither case will conductivity of the wire will not be disturbed.
The Torus does not employ piston operation of the packer; instead it uses direct hydraulic force. This allows the packer engaging the object in the bore to be carefully regulated, which keeps it from closing with excessive force. Very often fiberglass tubing will be used in EOR projects. To prevent collapse, the operator is advised to carefully monitor the closing force of the blowout preventer.
The Torus employs a very simple pressure close, vent open method of operation. To close, hydraulic pressure is applied via an outside source, i.e. an accumulator or rig hydraulics. To open, the same line permits the hydraulic fluid to vent back to the hydraulic reservoir. A simple regulator installed in the line will give the amount of pressure necessary for the packer to engage the object in the hole to effect a “shut-off”, but not more than what is required to overcome the downhole pressure.
There are no metal ‘fingers’ in the Torus packing element .