Abstract: A tapered sleeve and fracturing head system for introducing fracturing fluid to a wellbore, while protecting a conveyance string from the erosive effects of the fracturing fluid is disclosed. A tapered sleeve has a top portion and a tapered downhole portion. The sleeve is fit to a main bore of a fracturing head by an upset at the top portion of the sleeve that engages a shoulder of the fracturing head. The sleeve intercepts, deflects and redirects introduced fracturing fluids downhole, preventing direct impingement of the fracturing fluid against the conveyance string. The main bore of the fracturing head may also be tapered at an angle substantial parallel to and along the length of the taper of the sleeve, to further improve the fluid dynamics of the fracturing fluid and further reduce the erosive effects of the fracturing fluid.

Abstract: A packoff nipple for sealing an annular space in a well pipe has a tubular body, a sealing assembly positioned around the tubular body capable of axial movement along the tubular body and a stop to restrain the sealing assembly from extruding into the annular space. The sealing assembly includes one or more elastomeric sealing rings having a circumferential groove formed in a downhole face. An axially moveable actuator, such as a packer cup, engages the sealing ring assembly to cause at least a portion of the sealing rings to expand radially outwardly to seal the annular space and cause the sealing ring assembly to contact the uphole stop. The sealing rings are axially compressed between the uphole stop and the actuator to further expand the sealing rings. The uphole stop may be concave to urge the sealing rings away from the well pipe to avoid extrusion or permanent deformation.

Abstract: A packoff nipple is provided for sealing an annular space in a well pipe. The packoff nipple generally comprises a tubular body and a sealing assembly positioned around the tubular body and axially moveably thereon. A stop restrains the sealing assembly from extruding in to the annular space. The sealing assembly includes one or more elastomeric sealing rings having a circumferential groove formed in a downhole face. An axially moveable actuator, preferably a packer cup, engages the sealing ring assembly to causes at least an expansion portion of the sealing rings to expand radially outwardly to seal the annular space and the sealing ring assembly to contact the uphole stop. The sealing rings are axially compressed between the uphole stop and the actuator to further expand the sealing rings. Preferably the uphole stop is concave to urge the sealing rings away from the well pipe and thus further avoid extrusion.