Flow pulsing apparatus for down-hole drilling equipment

(19)

(11)

EP 0 333 484 A3

(12)	EUROPEAN PATENT APPLICATION

(88)	Date of publication A3:
	28.03.1990 Bulletin 1990/13

(43)	Date of publication A2:
	20.09.1989 Bulletin 1989/38

(21)	Application number: 89302618.7

(22)	Date of filing: 16.03.1989

(51)	International Patent Classification (IPC)⁴: E21B 7/24, E21B 21/00, E21B 4/14, E21B 7/18

(84)	Designated Contracting States:
	DE FR GB NL

(30)

Priority:

18.03.1988 GB 8806465

(71)	Applicant: INTECH INTERNATIONAL INC.
	Edmonton Alberta T5R OP3 (CA)

(72)	Inventor:
	Walter, Bruno Hartwig Edmonton Alberta (CA)

(74)	Representative: Gallafent, Richard John et al
	GALLAFENT & CO. 8 Staple Inn London WCIV 7QH London WCIV 7QH (GB)

(56)

References cited: :

(54)	Flow pulsing apparatus for down-hole drilling equipment

(57) Flow pulsing apparatus is adapted to be connected in a drill string above a drill bit. The apparatus includes a housing providing a passage for a flow of drilling fluid toward the bit. A valve which oscillates in the axial direction of the drill string periodically restricts the flow through the passage to create pulsations in the flow and a cyclical water hammer effect thereby to vibrate the housing and the drill bit during use. Drill bit induced longitudinal vibrations in the drill string can be used to generate the oscillation of the valve along the axis of the drill string to effect the periodic restriction of the flow or, in another form of the invention, a special valve and spring arrangement is used to help produce the desired oscillating action and the desired flow pulsing action.

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