EP0309030A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Sinusoidal pressure pulse generator for measurement while drilling tool
Assignee: Anadrill International SA
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Filing: 1988-09-12
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Granted: —
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Expires: 2008-09-12
Abstract
Abstract A pressure pulse generator which generates relatively sinusoidal pressure pulses in a fluid flowing in a borehole is disclosed. The pressure pulse generator for a MWD tool broadly comprises: a housing adapted to the connected in a tubing string so that fluid flowing in the string will at least partially flow through the housing; a stator mounted within the housing and having a plurality of lobes with intervening gaps; and rotor coaxial to the stator which rotates relative to the stator and which is mounted within the housing and has a plurality of lobes with intervening gaps between adjacent lobes, wherein the lobes of the rotor and stator are arranged such that as the rotor rotates relative to the stator, the area of the adjacent gaps between the lobes of the stator and rotor through which the fluid may flow in a direction parallel to the borehole varies approximately with the inverse of the square root of a linear function of a sine wave. Preferaly, the geometrical arrangement of the stator and rotor are substantially identical with a plurality of lobes with intervening gaps around a central circular hub. A first side of each lobe is defined by a radial extension from the circular hub, and the second side of each lobe is substantially parallel to the first side.
Inventors
- 👤 David Malone
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 18:56
CPC Classifications
E; E21; E21B; E21B47/00; E21B47/12; E21B47/14; E21B47/18
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
205 words
A pressure pulse generator (32) for generating pulses in fluid flowing in a borehole (23), comprising: a) a housing (42) adapted to be connected in a tubing string (21) so that fluid flowing in the string will at least partially flow through the housing; b) a stator (40) mounted within the housing and having a plurality of lobes (71) with intervening gaps between adjacent lobes serving to present a plurality of ports for the passage of fluid flowing through the housing; and c) a rotor (41) mounted coaxial to the rotor within the housing and having a plurality of lobes (72) with intervening gaps between adjacent lobes serving to present a plurality of ports for the passage of fluid flowing through the housing, wherein the rotor rotates relative to the stator, and wherein the lobes (71, 72) of the rotor (41) and stator 40 are characterized in that they are arranged such that as the rotor rotates relative to the stator, the area of the adjacent gaps between the lobes of the stator and rotor through which the fluid may flow in a direction parallel to the borehole varies approximately with the inverse of the square root of a linear function of a sine wave.
Claim 2
Dependent Claim
205 words
A pressure pulse generator (32) for generating pulses in fluid flowing in a borehole (23), comprising: a) a housing (42) adapted to be connected in a tubing string (21) so that fluid flowing in the string will at least partially flow through the housing; b) a stator (40) mounted within the housing and having a plurality of lobes (71) with intervening gaps between adjacent lobes serving to present a plurality of ports for the passage of fluid flowing through the housing; and c) a rotor (41) mounted coaxial to the rotor within the housing and having a plurality of lobes (72) with intervening gaps between adjacent lobes serving to present a plurality of ports for the passage of fluid flowing through the housing, wherein the rotor rotates relative to the stator, and wherein the lobes (71, 72) of the rotor (41) and stator 40 are characterized in that they are arranged such that as the rotor rotates relative to the stator, the area of the adjacent gaps between the lobes of the stator and rotor through which the fluid may flow in a direction parallel to the borehole varies approximately with the inverse of the square root of a linear function of a sine wave.
Claim 3
Dependent Claim
26 words
A pressure pulse generator (32) according to claim 1, characterized in that: the geometrical arrangement of said stator (40) and said rotor (41) are substantially identical.
Claim 4
Dependent Claim
73 words
A pressure pulse generator according to claim 1, characterized in that: said stator (40) and said rotor (41) preferably each include a plurality of lobes (71, 72) with intervening gaps around a central circular hub (150, 160), with a first side (152, 162) of each lobe substantially defined by a radial extension from said circular hub, and with the second side (154, 164) of each lobe being substantially parallel to said first side.
Claim 5
Dependent Claim
36 words
A pressure pulse generator (32) according to claim 3, characterized in that the outside edges (156, 166) of said lobes (71, 72) are preferably located substantially along a circle concentric with the circular hub (150, 160).
Claim 6
Dependent Claim
94 words
A pressure pulse generator (32) according to claim 4, characterized in that: the angle ϑ defined by the origin of said circular hub, the intersection of a first side of a lobe and the outer edge, and the intersection of the second side of the same lobe and the outer edge is substantially equal to the angle φ defined by the origin of the circular hub, the intersection of the first side of a lobe and the outer edge, and the intersection of the second side of an adjacent lobe and the outer edge.
Claim 7
Dependent Claim
35 words
A pressure pulse generator (32) according to claim 5, characterized in that: said rotor (40) and said stator (41) each have six lobes, and said substantially equal angles (ϑ, φ) are equal to thirty degrees.
Claim 8
Dependent Claim
37 words
A pressure pulse generator (32) according to claim 6 characterized in that: said rotor (40) and said stator (41) each have five lobes, (71, 72) and said substantially equal angles (ϑ, φ) are equal to thirty-six degrees.
Claim 9
Dependent Claim
85 words
A pressure pulse generator (32) according to claim 7 characterized in that: the area (A) of the adjacent gaps between the lobes (71, 72) of the stator (40) and rotor (41) through which the fluid may flow in a direction parallel to the borehole varies in time (t) substantially according to A(t) = 1/ (K + a sin wt) 1/2 where a is a function of the amplitude of the sine wave, w is the frequency of the sine wave, and K is a constant.
Claim 10
Dependent Claim
42 words
A pressure pulse generator (32) according to claim 8 characterized in that: the amplitude of said sine ave is a/2, and K is set to a/2 + O where O is an offset value, and the amplitude a/2 is a positive value.
References Cited (Backward Citations)
US3309656A
Cited
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