Abstract: A downhole check valve includes a body (32) defining a flow passage and a valve assembly (34, 42, 44) mounted in the body, the valve assembly including a valve member (34) movable from a first configuration to a second configuration. In the first configuration the valve member prevents flow in one direction through the passage, and in the second configuration the valve member is retained in an open position. A valve member retaining sleeve (48) is normally restrained in a first configuration and biassed for movement to a second configuration. The retainer is held in the first configuration while the valve member (34) is in the first configuration and is releasable from the first configuration to move the valve member to the open position and retain the valve member in the open position.

Abstract: A downhole running and expansion tool for mounting on a string in combination with a length of expandable tubing, the tool including a mounting portion defining a ratchet thread for engaging a corresponding thread defined by the expandable tubing, the thread preventing axial separation of the tool and tubing and releasably restraining the tool against axial movement into the tubing. Releasable retainers, such as shear pins may also be provided between the tool and tubing. On reaching the desired location in a bore, a combination of downwards jars and weight release the shear pins and moves the tool thread past the tubing thread. The tool includes an expander cone which is pushed through the tubing to expand the tubing to the desired diameter.

Abstract: Expandable tubing, as utilized in downhole applications in the oil and gas exploration and extraction industries, includes tubing having a wall with a multiplicity of overlapping longitudinally extending slots therein. The slots have end portions and at least some of the slots are wider at at least one end portion.

Abstract: A downhole running tool (10) for use in positioning an item, such as a length of tubing (12) , in a bore comprises a body (11, 22) defining a fluid passage, an arrangement (20, 30) for creating a flow restriction, to create an increase in fluid pressure in the passage, and a fluid actuated retaining member (34) mounted on the body for engaging an item (12) to be carried into a bore on the tool (10). The retaining member (34) is in fluid communication with the body fluid passage above the flow restriction arrangement (20, 30) and is movable to a retracted position to release the item (12) by application of fluid pressure forces.

Abstract: Downhole apparatus is disclosed for use in expanding liner or tubing. The apparatus comprises a body for connection to a string and an expansion portion on the body. The expansion portion includes a plurality of radially movable parts for defining an outer surface thereof. The parts are initially arranged in an axially and circumferentially offset first configuration in which the parts may assume a smaller diameter first configuration. The apparatus is then run Into a borehole and through a length of expandable tubing. The parts are the moved radially outwardly and axially aligned such that the parts assume a larger diameter second configuration and define a substantially continuous outer circumference. The expansion portion is then pulled through the tubing to expand the tubing.

Abstract: A connector assembly (20) for connecting expandable slotted tubing (EST) (10) comprises tubular first and second parts (22, 24) for mounting on the ends of respective lengths of slotted tubing. The parts (22, 24) are themselves slotted (26). The free end of the first part defines a male portion (28) and the free end of the second part defining a female portion (30), the free ends of the parts being adapted to engage with one another and to permit expansion of the coupled parts in a corresponding manner to the tubing (10).