| 摘要 |
A cement control device or sub (1) is provided for use in a well pipe (26) of a well and comprises a pipe assembly in the form of a pair of pipe sections (2A, 2B) which sandwich a central control member or ring (10) joined to the sections (2A, 2B), the assembly having ends (9A, 9B) adapted for fitting into a well pipe string as a section thereof. For control of fluid flow (e.g. cement) through the pipe assembly, a primary sleeve (5) is movably located within the pipe assembly (2A, 2B) while an additional fluid control sleeve (6) is movable with the primary sleeve (5). The primary sleeve (5) has a fluid inlet (8) at the upper end and a fluid outlet (7) at the bottom, together with a secondary outlet in the form of ports (13) in the wall of the sleeve (5). The primary sleeve (5) is movable from a closed to an open position. The outlet end (7) of the additional control sleeve (6) is closable by a ball (22) and the sleeve (6) is movable, with the primary sleeve (5) in the closed position to allow circulating fluid flow via ports (18, 19) on the primary sleeve and on the control member (10); and further when the primary sleeve (5) is then moved to the open position these ports (18, 19) are closed while cement can pass via the secondary outlet ports (13) to the discharge end (3) of the pipe assembly; the primary sleeve (5) is held in the closed position by shear pins (14). |
