Abstract: A bypass valve has a tubular housing for connection in series with a wellbore tubing string supporting a sliding sleeve biased from an open position towards a closed position relative to a bypass port in the housing. A first sealing interface between the sleeve and housing at one side of the port to maintain a fluid seal throughout sliding movement, while a second sealing interface between the sleeve and the housing at an opposing second side of the port maintains a fluid seal only in the closed position. A spring applies a prescribed closing force to the sliding sleeve to retain the sliding sleeve in the closed position only when pressure within the tubular housing which acts on the sliding sleeve through the bypass port is below the prescribed closing force of the spring.

Abstract: A rod positioning tool mounts in series between a tubing string and the stuffing box of a drive head. An outer mandrel of the tool mounts to a first flange at the bottom end for connection to the tubing string below and an inner mandral mounts to a second flange for connection to the stuffing box above. The inner mandrel is slidably received within the outer mandrel with primary seals therebetween to vary the overall length of the tool using one or more actuators between the flanges, while maintaining a sealed connection between the tubing string and the stuffing box. Keys on the outer tubular mandrel are longitudinally slidable in keyways on the inner tubular mandrel to resist relative rotation between the mandrels. A secondary seal provides a sealed connection between the second flange and the top end of the outer mandrel in a fully retracted position of the tool.

Abstract: A rod positioning tool mounts in series between a tubing string and the stuffing box of a drive head. An outer mandrel of the tool mounts to a first flange at the bottom end for connection to the tubing string below and an inner mandral mounts to a second flange for connection to the stuffing box above. The inner mandrel is slidably received within the outer mandrel with primary seals therebetween to vary the overall length of the tool using one or more actuators between the flanges, while maintaining a sealed connection between the tubing string and the stuffing box. Keys on the outer tubular mandrel are longitudinally slidable in keyways on the inner tubular mandrel to resist relative rotation between the mandrels. A secondary seal provides a sealed connection between the second flange and the top end of the outer mandrel in a fully retracted position of the tool.

Abstract: A stuffing box apparatus for sealing between a polish rod in a hydrocarbon production well comprises a tubular housing arranged for connection to the well which has a bore therethrough to receive the polish rod. Sealing members are supported in the bore of the housing in an upper stack and a lower stack of smaller outer diameter separated by an intermediate bushing. An upper bushing compresses the upper stack against the intermediate bushing. The lower bushing fixes the lower stack against the bottom of the intermediate bushing. Each of the bushings includes a counter bore formed at one end which receives a wiper member arranged for sealing engagement between the bushing and the polish rod.

Abstract: A stuffing box apparatus for sealing between a polish rod in a hydrocarbon production well comprises a tubular housing arranged for connection to the well which has a bore therethrough to receive the polish rod. Sealing members are supported in the bore of the housing in an upper stack and a lower stack of smaller outer diameter separated by an intermediate bushing. An upper bushing compresses the upper stack against the intermediate bushing. The lower bushing fixes the lower stack against the bottom of the intermediate bushing. Each of the bushings includes a counter bore formed at one end which receives a wiper member arranged for sealing engagement between the bushing and the polish rod.