초록 ▼

Downhole flow pulsing apparatus comprises a housing (14) for location in a drillstring, the housing (14) defining a throughbore to permit passage of fluid through the housing. A valve (27, 30) is located in the bore and defines a flow passage (29, 31). The valve includes a valve member (27) which is

Downhole flow pulsing apparatus comprises a housing (14) for location in a drillstring, the housing (14) defining a throughbore to permit passage of fluid through the housing. A valve (27, 30) is located in the bore and defines a flow passage (29, 31). The valve includes a valve member (27) which is movable to vary the area of the passage (29, 31) to provide a varying fluid flow therethrough. A fluid actuated positive displacement motor (15, 16) is associated with the valve member (27). In a preferred embodiment, the apparatus is provided in combination with a drill bit (5) and a pressure responsive device, such as a shock-sub (3), which expands or retracts in response to the varying drilling fluid pressure created by the varying flow passage area. The expansion or retraction of the shock-sub (3) provides a percussive effect at the drill bit.

대표청구항 ▼

Downhole flow pulsing apparatus comprises a housing (14) for location in a drillstring, the housing (14) defining a throughbore to permit passage of fluid through the housing. A valve (27, 30) is located in the bore and defines a flow passage (29, 31). The valve includes a valve member (27) which is

Downhole flow pulsing apparatus comprises a housing (14) for location in a drillstring, the housing (14) defining a throughbore to permit passage of fluid through the housing. A valve (27, 30) is located in the bore and defines a flow passage (29, 31). The valve includes a valve member (27) which is movable to vary the area of the passage (29, 31) to provide a varying fluid flow therethrough. A fluid actuated positive displacement motor (15, 16) is associated with the valve member (27). In a preferred embodiment, the apparatus is provided in combination with a drill bit (5) and a pressure responsive device, such as a shock-sub (3), which expands or retracts in response to the varying drilling fluid pressure created by the varying flow passage area. The expansion or retraction of the shock-sub (3) provides a percussive effect at the drill bit. rotor to the valve member. 7. Downhole apparatus comprising: a housing for location in a tubing string, the housing defining a throughbore to permit passage of fluid therethrough; a device including a member which is transversely movable relative to an axis of the housing; and a fluid actuated positive displacement motor having a rotor coupled to the member for communicating transverse movement of the rotor to the member. 8. A flow pulsing drilling method comprising the steps: providing a valve in a drill string bore including first and second valve members each defining a respective axial flow opening and which openings collectively define an open axial flow port through the valve, the first member being rotatable about a longitudinal axis of the housing to vary the alignment of the openings, the openings being arranged such that in a complete rotation of the first member about said longitudinal axis the openings are always at least partially aligned and the axial flow port varies in area between a minimum first open area when the first member is positioned in a first alignment and a maximum second open area when the first member is positioned in a second alignment; and rotating the first member about said longitudinal axis to vary the alignment of the openings between said first alignment and said second alignment to provide variable flow therethrough and thus produce varying fluid pressure in the drilling fluid.