Patent GB-537625-A (GB)
Title: Improvements in or relating to packing heads for wells
IPC: E21B33/06
Filed: 1940-01-26
Abstract: 537,625. Packing heads for wells; valves. HYDRIL CO. OF CALIFORNIA. Jan. 26, 1940,  No. 1643. Convention date, Jan. 27, 1939. [Class 85] [Also in Group XXIX] Relates to packing heads for wells and comprises the provision of (1) a valve adapted to allow passage of packer-actuating fluid to and from the packer housing, the valve acting automatically to prevent continued flow from said housing on a sudden fall of inlet pressure, as from the inlet pipe breaking, (2) a passage way' in the housing for admission of well pressure to raise a packer-contracting member, and (3) means for supporting the packer. In Fig. 3, the housing 13 has larger and smaller bores 14, 18, connected by a conical bore 17 with grooves 53, a piston 35 having larger and smaller heads 36, 37, fitting the bores 14. 18. A passage 59 is adapted to lead pressure fluid from the well to chamber 54 to act on intermediate piston surface 48 ; a ball valve 69 co-operates with a seat provided with bleed ports to prevent substantial return flow, while a threaded valve 74 may cut off flow in either direction, and a horizontal passage 75, Figs. 3 and 5, contains a spring- pressed ball valve 82 which permits excess pressure to escape from chamber 54 to vertical passage 79. Pressure fluid from an external source may be admitted through a valve 86, Fig. 3, guarded and supported by a bracket 106, while if a sudden outflow of fluid occurs, as through fracture of the inlet pipe, a ball valve 92, adjustably supported by a threaded plug 95, is carried by the fluid to a seat 100 to close the outlet ; a byepass 101 prevents ball 92 closing the inlet to chamber 54. The packer P, deformed by upward movement of piston 35, has a doubletapered lower end fitting the bore of piston 35. a downward lip 112 preventing upward leakage of fluid ; reinforcement is provided at 124 in the packer which is suspended by fabric 122 held between interlocking parts of connected rings 144, 149. The ring 144 is threaded to a ring 133 threaded to a cap ring 125 itself threaded to the housing 13, the cap ring having an internal diameter adapted to pass the packer P. A locking bar 130, with hinged end 138; is adapted to prevent relative movement between housing 13, cap ring 125, and ring 133, the latter being internally threaded to receive apparatus such as a tandem packer, and having tool-receiving openings 140. Held to the ring 144 by dowels 199 is a ring 195 below which is a bushing 190 comprising segments 191, Fig. 9, pivoted on a split ring 197, coil springs 205 tending to hold the segments outwardly ; each segment has an outer, arcuate and preferably hollow lug 200 and depending finger 192, the segments in their inner positions forming a rigid conical bushing, while inter-engaging lugs 209 and recesses 210 ensure simultaneous movement of the segments. An inlet 158 allows admission &c. of pressure fluid to the upper end of the piston 35 and a passage 156 permits the housing to be flushed. Screws 160, threaded to the cap ring 125, limit movement of the piston. The position of the piston is indicated directly or indirectly by means comprising a rod 167, Fig. 8, movable through cap ring 125 and pressed by a spring 172, the rod carrying a piston 176 moving in a cylinder 173 and a passage 177 conveying pressure fluid to the upper end of the piston to counteract upward pressure on the rod. The pressure-fluid supply means may include a pressure booster. In another form, Fig. 13, the bushing 190 is replaced by an inner rubber &c. bushing 225 with a reinforced bead 227 engaging a suspension ring 230 normally locked by a spring-pressed latch 231. A sleeve 233 is threaded to the ring 230, its movement being limited by a ring 235, and on downward movement of the sleeve 233, a cone 237, welded thereto and provided with tool-receiving openings 238, forces a split locking ring 239 into a groove in the ring 133. Undue deformation of the lower end of the main packer is prevented by a ring 251 of material similar to the main packer and engaging a groove 252 therein, ring 251 being reinforced by spaced, rigid, segmental inserts 254 with apertures 256 into which the material of the ring is moulded.