Abstract: A casing cementer with torque-limiting rotating positioning tool. The casing cementer comprises a housing with a rotating valve sleeve therein. A positioning tool is used to rotated the valve sleeve between open and closed positions thereof. No reciprication of the positioning tool is required. The valve sleeve has a sealing ring molded thereto for sealing between the housing and the valve sleeve. The valve sleeve preferably has an inside diameter at least as large as an inside diameter of the casing. A stop is provided to limit movement of the valve sleeve when it reaches either the open or closed position. A clutch in the positioning tool provides for torque-limitation and a ratcheting indication to the operator at the surface when the valve sleeve has been opened or closed.

Abstract: A variable displacement pump is controlled throughout a broad range of operating conditions between a maximum pressure, low flow rate combination and a minimum pressure, high flow rate combination even when the pump is driven by a power limited prime mover. Different relief valves set at different operating pressures are automatically selectably connected to a control port of the pump in response to the actual flow rate of the fluid pumped by the pump reaching different flow rate set points.

Abstract: A multiple stage inflation packer with secondary opening rupture disc. The inflatable packer comprises a case with a closing sleeve, an opening sleeve and a releasing sleeve therein. An opening plug is dropped into the casing string and is allowed to free fall, or is pumped down, to actuate the opening sleeve to allow inflation of the packer element. A back check valve prevents the packer from deflating. After the packer is inflated, additional pressure is applied which ruptures a rupture disc to open a port to the well annulus above the set packer element. Cementing may be carried out through this port, and after the cementing operation, a closing plug is pumped down the well casing behind the cement to actuate the releasing sleeve and move the closing sleeve to seal off the ports. Another check valve insures that pressure is equalized on both sides of the rupture disc as the packer is run into the well bore.

Abstract: A protective cover assembly for a fluid end of a plunger-type pump or other positive displacement pump. The protective cover assembly includes a cover adapted to fit in an open end of the fluid end of the pump. The cover comprises a convex or domed center portion adapted for buckling away from a plunger of the pump when pressure in the pump exceeds a predetermined level and further comprises an outer portion. A cover retainer is engageable with the open end of the fluid end of the pump and is adapted for clamping the outer portion of the cover to the fluid end. A seal is provided between the outer portion of the cover and the fluid end. The convex center portion of the cover has a convex surface generally facing the plunger, and the convex surface is preferably hemispherical.