Abstract: Well derrick in which the travelling crown block is operated by hydraulically operated linear actuators and a travelling block is operated by special reeving, the arrangement advantageously being such that the loads being handled bypass the tower of the derrick so that the cost of the tower can be reduced. The reeving system results not only in uniform and symmetrical force distribution relative to the crown block and travelling beam but also in a travel of the travelling beam twice the stroke of the linear actuators.

Abstract: A flow control and safety valve for oil wells where control of flow in the casing annulus is accomplished with a wire-line retrievable device. A basic valve structure provides for control of flow in the casing annulus by means of a control line to the surface. A number of additional functions can be added to the basic valve structure to accomplish control of flow through the tubing string and can accommodate control of dual and triple zone recovery. These additional functions are accomplished by landing additional wire-line retrievable valves within the basic structure whereby independent control of the annulus and tubing string flows is possible, at the same time affording increased flow diameters for a greater volume of production in a given casing size.