摘要:
A composite stator construction for a downhole drilling motor which provides improved sealing and distortion properties. The elastomer which maintains the sealing/pumping action of the motor is applied in a uniform thickness to a rigid metallic form. In the stator, the rigid former has the basic configuration of the stator and is mounted within the casing of the motor. In the rotor, the elastomer can be applied directly to a metallic rotor core. The basic geometry is provided by the metallic former thereby reduces distortion of the lobes under increased torsional forces.
摘要:
A downhole motor (19) is mounted in a drill pipe (13) above a hole enlarger (14) intermediate ends of the pipe (13). The motor drives a lower pilot bit (28). A split flow bypass device (24) above the motor (19) allows part of the flow to drive the motor and the remainder to bypass through a central passage, the divided flows rejoining below the motor (19) with a restricted flow through jet nozzles (32) to the hole enlarger cutter (15). Flow passes centrally of the output shaft (26), past a bleed valve (34) bleeding up to 5% to an outer shaft space for lubricating bearings (30), to flow restrictor jet nozzles (33) of the pilot bit (28). In use flow is controlled to drive the motor (19) to drive the pilot bit (28) at desired speed and the drill string is rotated from the rotary platform of a drill rig to drive the hole enlarger (14) so that the hydraulic requirements of the hole enlarger (14) and the pilot bit (28) are met while only allowing sufficient fluid to pass through the motor (19) to give the required output speed at the pilot bit (28).
摘要:
Allocating limited manufacturing resources to achieve a feasible production plan that is consistent with customer demand is a difficult and common problem faced in many manufacturing industries. For large-scale multi-stage manufacturing systems, existing methods are typically based either on allocating limited resources sequentially, according to a priority ranked list of production starts, or on linear programming based models. The output of such planning models is a production plan which specifies the quantity of each part to produce at each plant, using resources available to the enterprise. Typically there are lot-sizing rules defining the permissible production start quantities. The invention disclosed herein is a method for applying these rules to the lot-sizing of production starts within a linear program. It employs advanced heuristics that consider both established operational objectives (e.g. customer service, short lead times, low inventory, and prioritized allocation of supply and capacity) and lot-size rules to efficiently compute a feasible production plan for the division.
摘要:
A stabilizer sleeve (7) for a drill string, adapted to fit about a down hole motor (1) or a drill string member, is formed with an internally threaded coupling at a lower end for releasable coupling to complimentary threads (8) formed on an upwardly extending intermediate coupling portion (15) of a bottom coupling-nut (3). The coupling-nut (3) is provided with a lower end portion (14) of larger diameter and an upper coupling portion (16) of reduced diameter. The upper coupling portion (16) is conventionally formed with an upwardly tapering form and right-hand thread whereas the intermediate coupling portion (15) is formed with a left-hand thread. The stabilizer sleeve (7) fits about the motor (1) or other body member and above the coupling-nut (3) so that the sleeve (7) may be removed upwardly from the coupling-nut (3).
摘要:
A drop-ball sub-assembly comprises a tubular casing (4) defining a flushing fluid flow passage adapted for coupling at one end (3) to an inlet pipe (1) and at the other end (23) to an outlet pipe (24). A drop-ball (17) supporting member (8) is secured within the casing (4) in the flow passage. Apertures (21) are arranged to allow fluid flow past the supporting member (8), and a further aperture (9) supports a blow-out device (13) supporting a drop-ball (17) on a side distal from the end (23). The blow-out device (13) and the apertures (21,9) are such that at a first, lower fluid rate from the inlet (3) to the outlet (23) end, fluid flows through said aperture (21) and the blow-out device is retained, and that at a second, higher flow rate the blow-out device (13) is blown out of the further aperture to release the ball (17) through the further aperture (9). The blow-out device suitably comprises a frangible disc.