Patent EP0131351A2 successfully refreshed from Google Patents.
EP0131351A2
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A method of determining the permeability of a formation
Assignee: Mobil Oil AS
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Filing: 1984-03-27
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Granted: —
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Expires: 2004-03-27
Abstract
Abstract In a method for determining the permeability of a formation, a borehole is traversed with a logging tool 10 having a transmitter 24 for transmitting low frequency acoustic energy. The transmitter 24 is pulsed at a plurality of locations in the borehole and the produced acoustic energy is detected at spaced first and second receivers 28, 32, each having a low frequency response sufficient to detect tube waves in the acoustic energy. The arrival times of a tube wave at each of the spaced receivers 28, 32 are determined for each of a plurality of locations in the borehole so that values can be calculated representing the velocity of the tube wave for each of the plurality of locations. A record of said values is then formed for the plurality of locations corresponding to the traversal of the borehole by the logging tool 10.
Inventors
- 👤 Frank Anthony Angona
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 13:31
CPC Classifications
G; G01; G01V; G01V1/00; G01V1/40; G01V1/44; G01V1/48; G01V1/50
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
168 words
A method of determining the permeability of a formation, comprising the steps of: traversing a borehole with a tool having means for transmitting low-frequency acoustic energy: pulsing said transmitting means at a plurality of locations in said borehole to produce acoustic energy therein; detecting for each location said produced acoustic energy at a first receiver having a low frequency response sufficient to detect tube waves in said acoustic energy; detecting for each location said produced acoustic energy at a second receiver, spaced from the first, and having a low frequency response sufficient to detect tube waves in.said acoustic energ; determining respective arrival times of a tube wave at each of said first and second receivers for said plurality of locations; determining a value representing the velocity of said tube wave from said arrival times for each of said plurality of locations; and forming a record containing values representing tube wave velocity for each of said plurality of locations corresponding to the traversal of said borehole with said tool.
Claim 2
Independent Claim
168 words
A method of determining the permeability of a formation, comprising the steps of: traversing a borehole with a tool having means for transmitting low-frequency acoustic energy: pulsing said transmitting means at a plurality of locations in said borehole to produce acoustic energy therein; detecting for each location said produced acoustic energy at a first receiver having a low frequency response sufficient to detect tube waves in said acoustic energy; detecting for each location said produced acoustic energy at a second receiver, spaced from the first, and having a low frequency response sufficient to detect tube waves in.said acoustic energ; determining respective arrival times of a tube wave at each of said first and second receivers for said plurality of locations; determining a value representing the velocity of said tube wave from said arrival times for each of said plurality of locations; and forming a record containing values representing tube wave velocity for each of said plurality of locations corresponding to the traversal of said borehole with said tool.
Claim 3
Dependent Claim
57 words
The method of Claim 1, further comprising the step of observing changes in the values representing tube wave velocity from one portion of said record corresponding to one of said locations to another portion of said record corresponding to another of said locations to monitor changes in permeability of said formation between said one and another locations.
Claim 4
Dependent Claim
31 words
The method of Claim 1 of Claim 2 wherein said values representing tube wave velocity are determined and recorded as a difference in arrival time between said first and second receivers.
Claim 5
Dependent Claim
44 words
The method of Claim 1 or Claim 2 wherein said values representing tube wave velocity are determined and recorded as a difference in arrival time between said first and second receivers divided by a value representing the distance between said first and second receivers.
Claim 6
Independent Claim
25 words
The method of any preceding Claim wherein said record is in the form of a log of values representing tube wave velocity vs. borehole depth.
Claim 7
Independent Claim
25 words
The method of any preceding Claim wherein said first and second receivers have a frequency response under borehole conditions of O.lk Hz to 30k Hz.
Claim 8
Independent Claim
27 words
The method of any preceding Claim wherein said first receiver is spaced from said transmitting means by a cable having a length exceeding 5 feet (1.52 m).
Claim 9
Dependent Claim
15 words
The method of Claim 7, wherein said cable length is about 15 feet (4.57 m).
Claim 10
Independent Claim
23 words
The method of any preceding Claim wherein said first and second receivers are spaced by a distance of about 5 feet (1.52 m).
Claim 11
Independent Claim
18 words
The method of any preceding Claim wherein said first and second receivers are interconnected solely by a cable.
References Cited (Backward Citations)
No citation records indexed.
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