CASING-HEAD STUFFING BOX Russian patent published in 2003 - IPC

FIELD: mechanical engineering, particularly, oil gas producing industry; applicable in designing of wellhead equipment including sealing device of sealed surfaces of polished rod in reciprocation of walking beam of sucker road pump. SUBSTANCE: to reduce forces the pressing the sealing units to sealed surfaces of polished rod and bending moments acting on casing-head stuffing box, tee joint has annular recesses accommodating sealing units and inserts. Cover end has threaded holes made concentrically over circumference with pressure bolts for successive action on operating and stand-by sealing units through intermediate and upper inserts. Wall of external surface of tee joint has threaded holes with tightly installed pressure screws for acting on emergency sealing unit through lower insert. To reduce size and weight characteristics of casing-head stiffing box and, as a result, bending moments acting on device, tee joint wall, has channels of hydraulic communication between inner diameter of tubing hanger and flow line of crude oil collector. To provide for making hydraulic communication channels in tee joint wall, sealing gasket is made combined with concentrical displacement of sealing surfaces for engagement with companion sealing surfaces of conical grooves of device and wellhead equipment. Use of offered casing-head stuffing box on oil wells provided with pumping unit makes of possible to increase longevity of sealing units, to reduce size and weight characteristics of casing-head stuffing box, to provide for higher operate reliability, fire safety and industrial ecology. EFFECT: higher efficiency of use of offered casing-head stuffing box. 3 cl, 1 dwg