US3716830A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic noise filter with hose reflection suppression
Assignee: Individual
•
Filing: 1970-12-18
•
Granted: 1973-02-13
•
Expires: 1990-12-18
Abstract
Abstract An illustrative embodiment of the present invention includes methods and apparatus for detecting pressure pulse signals from a remote signalling device in the mud line of a well while the well is being drilled and in the presence of mud pump pressure pulse noise. The apparatus and methods include placing plural pressure sensitive transducers in the mud line and at opposite ends of the flexible hose portion thereof between the metallic line from the mud pump and the rotary swivel portion which is attached to the kelly. Electrical transducer signals sensed on the mud pump end of the hose are processed to take into account the amplitude and phase shift effects of the hose and then delayed by a time sufficient for the pulse to traverse the hose. The processed signals are then combined with those from the second pressure transducer to directionally discriminate against the mud pump noise pulses while detecting pulses from downhole.
Inventors
- 👤 D Garcia
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 09:54
CPC Classifications
E; E21; E21B; E21B47/00; E21B47/12; E21B47/14; E21B47/18
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
295 words
A method for detecting information-conveying acoustic-frequency pressure signals being transmitted from within a well bore to the surface through a drilling fluid being pumped into said well bore through a tubular drill string coupled by at least one acoustically dissimilar tubular conduit to the discharge side of a drilling fluid pump producing spurious acoustic-frequency pressure signals which are transmitted through said drilling fluid toward said tubular conduit and said drill string, the method comprising the steps of: detecting said pressure signals in said drilling fluid at a selected measuring point downstream of said tubular conduit for producing a first electrical signal substantially representative of the combination of said information-conveying upstream signals which have traveled through said drill string to said downstream measuring point and said spurious pressure signals which have traveled through said tubular conduit to said downstream measuring point; detecting said spurious pressure signals in said drilling fluid at a selected measuring point upstream of said tubular conduit for producing a second electrical signal substantially representative of the combination at said upstream measuring point of said spurious pressure signals before they have traveled through said tubular conduit and spurious pressure signals reflected from said tubular conduit as a result of its acoustical dissimilarity; attenuating and delaying said second electrical signal in accordance with the expected attenuation and delay of said spurious pressure signals which have traveled between said upstream and downstream measuring points through said tubular conduit for producing a compensated second electrical signal substantially representative of said spurious pressure signals which have traveled through said tubular conduit to said downstream measuring point; and combining said first electrical signal with said compensated second electrical signal for producing an electrical output signal substantially representative of only said information-conveying pressure signals at said downstream measuring point.
Claim 2
Independent Claim
295 words
A method for detecting information-conveying acoustic-frequency pressure signals being transmitted from within a well bore to the surface through a drilling fluid being pumped into said well bore through a tubular drill string coupled by at least one acoustically dissimilar tubular conduit to the discharge side of a drilling fluid pump producing spurious acoustic-frequency pressure signals which are transmitted through said drilling fluid toward said tubular conduit and said drill string, the method comprising the steps of: detecting said pressure signals in said drilling fluid at a selected measuring point downstream of said tubular conduit for producing a first electrical signal substantially representative of the combination of said information-conveying upstream signals which have traveled through said drill string to said downstream measuring point and said spurious pressure signals which have traveled through said tubular conduit to said downstream measuring point; detecting said spurious pressure signals in said drilling fluid at a selected measuring point upstream of said tubular conduit for producing a second electrical signal substantially representative of the combination at said upstream measuring point of said spurious pressure signals before they have traveled through said tubular conduit and spurious pressure signals reflected from said tubular conduit as a result of its acoustical dissimilarity; attenuating and delaying said second electrical signal in accordance with the expected attenuation and delay of said spurious pressure signals which have traveled between said upstream and downstream measuring points through said tubular conduit for producing a compensated second electrical signal substantially representative of said spurious pressure signals which have traveled through said tubular conduit to said downstream measuring point; and combining said first electrical signal with said compensated second electrical signal for producing an electrical output signal substantially representative of only said information-conveying pressure signals at said downstream measuring point.
Claim 3
Independent Claim
295 words
A method for detecting information-conveying acousticfrequency pressure signals being transmitted from within a well bore to the surface through a drilling fluid being pumped into said well bore through a tubular drill string coupled by at least one acoustically dissimilar tubular conduit to the discharge side of a drilling fluid pump producing spurious acoustic-frequency pressure signals which are transmitted through said drilling fluid toward said tubular conduit and said drill string, the method comprising the steps of: detecting said pressure signals in said drilling fluid at a selected measuring point downstream of said tubular conduit for producing a first electrical signal substantially representative of the combination of said information-conveying upstream signals which have traveled through said drill string to said downstream measuring point and said spurious pressure signals which have traveled through said tubular conduit to said downstream measuring point; detecting said spurious pressure signals in said drilling fluid at a selected measuring point upstream of said tubular conduit for producing a second electrical signal substantially representative of the combination at said upstream measuring point of said spurious pressure signals before they have traveled through said tubular conduit and spurious pressure signals reflected from said tubular conduit as a result of its acoustical dissimilarity; attenuating and delaying said second electrical signal in accordance with the expected attenuation and delay of said spurious pressure signals which have traveled between said upstream and downstream measuring points through said tubular conduit for producing a compensated second electrical signal substantially representative of said spurious pressure signals which have traveled through said tubular conduit to said downstream measuring point; and combining said first electrical signal with said compensated second electrical signal for producing an electrical output signal substantially representative of only said informationconveying pressure signals at said downstream measuring point.
Claim 4
Independent Claim
295 words
A method for detecting information-conveying acousticfrequency pressure signals being transmitted from within a well bore to the surface through a drilling fluid being pumped into said well bore through a tubular drill string coupled by at least one acoustically dissimilar tubular conduit to the discharge side of a drilling fluid pump producing spurious acoustic-frequency pressure signals which are transmitted through said drilling fluid toward said tubular conduit and said drill string, the method comprising the steps of: detecting said pressure signals in said drilling fluid at a selected measuring point downstream of said tubular conduit for producing a first electrical signal substantially representative of the combination of said information-conveying upstream signals which have traveled through said drill string to said downstream measuring point and said spurious pressure signals which have traveled through said tubular conduit to said downstream measuring point; detecting said spurious pressure signals in said drilling fluid at a selected measuring point upstream of said tubular conduit for producing a second electrical signal substantially representative of the combination at said upstream measuring point of said spurious pressure signals before they have traveled through said tubular conduit and spurious pressure signals reflected from said tubular conduit as a result of its acoustical dissimilarity; attenuating and delaying said second electrical signal in accordance with the expected attenuation and delay of said spurious pressure signals which have traveled between said upstream and downstream measuring points through said tubular conduit for producing a compensated second electrical signal substantially representative of said spurious pressure signals which have traveled through said tubular conduit to said downstream measuring point; and combining said first electrical signal with said compensated second electrical signal for producing an electrical output signal substantially representative of only said informationconveying pressure signals at said downstream measuring point.
Claim 5
Dependent Claim
19 words
The method of claim 1 wherein said acoustically dissimilar tubular conduit is a flexible member including an elastomeric material.
Claim 6
Dependent Claim
75 words
The method of claim 1 wherein said attenuating and delaying step is performed by multiplying said second electrical signal by a function Rei , where R is the expected ratio of the amplitudes of said spurious pressure signals at said upstream and downstream measuring points respectively, and theta is the expected phase shift introduced by said tubular conduit on said spurious pressure signals traveling through said tubular conduit between said upstream and downstream measuring points.
Claim 7
Dependent Claim
277 words
Apparatus adapted for detecting information-conveying acoustic-frequency pressure signals being transmitted from within a well bore to the surface through a drilling fluid being pumped into the well bore through a tubular drill string coupled by at least one acoustically dissimilar tubular conduit to the discharge side of a drilling fluid pump which produces spurious acoustic-frequency pressure signals that are transmitted through the drilling fluid toward the tubular conduit and the drill string, and comprising: first pressure-detecting means adapted for producing a first electrical signal substantially representative of the combination of said information-conveying pressure signals at a selected measuring point adjacent to the downstream end of such a tubular conduit and said spurious pressure signals which have traveled therethrough to said selected downstream measuring point; second pressure-detecting means adapted for producing a second electrical signal substantially representative of the combination of said spurious pressure signals at a selected measuring point adjacent to the upstream end of such a tubular conduit and reflections therefrom as a result of said acoustic impedance mismatch; circuit means coupled to said second pressure-detecting means and adapted for attenuating and delaying said second electrical signal in accordance with the expected attenuation and delay provided by such a tubular conduit upon said spurious pressure signals traveling therethrough between said upstream and downstream measuring points to provide a compensated second electrical signal substantially representative of said spurious pressure signals detected at said downstream measuring points by said first pressure-detecting means; and output means responsive to said first electrical signal and said compensated second electrical signal and adapted for producing an electrical output signal substantially representative of only said information-conveying pressure signals at said downstream measuring point.
Claim 8
Dependent Claim
277 words
Apparatus adapted for detecting information-conveying acoustic-frequency pressure signals being transmitted from within a well bore to the surface through a drilling fluid being pumped into the well bore through a tubular drill string coupled by at least one acoustically dissimilar tubular conduit to the discharge side of a drilling fluid pump which produces spurious acoustic-frequency pressure signals that are transmitted through the drilling fluid toward the tubular conduit and the drill string, and comprising: first pressure-detecting means adapted for producing a first electrical signal substantially representative of the combination of said information-conveying pressure signals at a selected measuring point adjacent to the downstream end of such a tubular conduit and said spurious pressure signals which have traveled therethrough to said selected downstream measuring point; second pressure-detecting means adapted for producing a second electrical signal substantially representative of the combination of said spurious pressure signals at a selected measuring point adjacent to the upstream end of such a tubular conduit and reflections therefrom as a result of said acoustic impedance mismatch; circuit means coupled to said second pressure-detecting means and adapted for attenuating and delaying said second electrical signal in accordance with the expected attenuation and delay provided by such a tubular conduit upon said spurious pressure signals traveling therethrough between said upstream and downstream measuring points to provide a compensated second electrical signal substantially representative of said spurious pressure signals detected at said downstream measuring points by said first pressure-detecting means; and output means responsive to said first electrical signal and said compensated second electrical signal and adapted for producing an electrical output signal substantially representative of only said information-conveying pressure signals at said downstream measuring point.
Claim 9
Dependent Claim
32 words
The apparatus of claim 4 wherein said output means include a differential amplifier adapted for receiving said first electrical signal and said compensated second electrical signal to produce said electrical output signal.
Claim 10
Dependent Claim
76 words
The apparatus of claim 4 wherein said circuit means include electrical means for generating said compensated second electrical signal as a function of the product of said second electrical signal and a constant Rei , where R is the expected ratio of said spurious pressure signals respectively detected by said first and second pressure-detecting means, and theta is the expected phase difference between said spurious pressure signals respectively detected by said first and second pressure-detecting means.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-02-13 | 1976-08-14 | 1977-02-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-13 | 1980-08-14 | 1981-02-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-13 | 1984-08-14 | 1985-02-13 | $7700.00 | Window Closed / Lapsed |