| 摘要 |
A pressure pulse generator (1) for use in transmitting pressure signals to surface in a fluid-based drilling system (51) comprising : a housing (100) positionable in the path of the supply of pressurised fluid, said housing having an inlet arrangement (9, 10) for admitting a portion of the fluid to the interior of housing, and an outlet arrangement for discharging fluid from the interior of the housing for supply to the drilling assembly (59) ; a control element (10) slidably mounted in the housing (100) for movement between an open and a closed position with respect to said inlet arrangement (9, 10), said control element being operative to generate a pressure pulse in the supply of pressure fluid when the control element takes-up the closed position ; a control passage (27, 28) extending through the control elements (10) and closable by a pilot valve element (21) arranged to be exposed to the pressure of the fluid in the passage ; and, an actuator (13, 14, 15) coupled with the valve element (21) and operative, when the pressure generator is activated to generate a pressure signal, to move the valve element (21) to a position closing said passage (27, 28) and thereby to cause movement of the control element (10) towards the closed position ; the coupling between the actuator (13, 14, 15) and the valve element (21) includes a yieldable biassing element (20) which provides control of the amplitude of the pressure signals produces by the generator.
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