Patent US3900826A successfully refreshed from Google Patents.
US3900826A
Expired / Lapsed
US
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Acoustic permeability log utilizing differential travel time measurements
Assignee: Texaco Inc
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Filing: 1973-10-31
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Granted: 1975-08-19
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Expires: 1993-10-31
Abstract
Abstract A permeability logging tool adapted to be lowered to selected elevations in a well bore wherein fluids in any pore spaces in the formation adjacent to the well bore are excited by means of high peak amplitude acoustic pulses of short duration which form compressive and rarefaction wave fronts in the formation, thereby altering localized formation fluid pressure and creating a flow path from a point of high pressure to a point of relatively low pressure. A pair of sonic transceivers used as measuring transducers are also included on the tool. Acoustic signals are transmitted to and fro between these transducers. The change in signal transmission time between the transceivers due to fluid flow rate established by the electrical excitation is measured. The shift in transmission time between the measuring transducers is thus proportionate to the rate of fluid flow in the formation. This shift in time is thus fuctionally related to the permeability of the formation matrix material.
Inventors
- 👤 Donald J Dowling
- 👤 John F Boyd
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 08:27
CPC Classifications
G; G01; G01V; G01V1/00; G01V1/40; G01V1/44
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
81 words
A method for measuring permeability of a formation adjacent to a borehole comprising the steps of: exciting the formation by imposing acoustic radiation on the formation from two sources, one forming a compressive wave front and the other forming a rarefaction wave front to create fLuid flow in the formation; and, measuring the transit time of acoustic energy in the formation as modified by the fluid flow to determine the change in transit time as a measure related to the permeability.
Claim 2
Independent Claim
81 words
A method for measuring permeability of a formation adjacent to a borehole comprising the steps of: exciting the formation by imposing acoustic radiation on the formation from two sources, one forming a compressive wave front and the other forming a rarefaction wave front to create fLuid flow in the formation; and, measuring the transit time of acoustic energy in the formation as modified by the fluid flow to determine the change in transit time as a measure related to the permeability.
Claim 3
Dependent Claim
58 words
The method of claim 1 including the step of excitating the fluid in the formation in such a manner that fluid in the formation tends to flow in a first direction; and, wherein the measuring step includes transmitting ultrasonic energy through the formation along the first direction and measuring the time required for transmission over a specified distance.
Claim 4
Dependent Claim
38 words
The method of claim 2 including the step of transmitting ultrasonic energy in the first direction and opposite to the first direction and measuring the time change required for transmission over a specified distance in the two directions.
Claim 5
Dependent Claim
15 words
The method of claim 3 wherein two time measurements are made and the difference obtained.
Claim 6
Dependent Claim
16 words
The method of claim 1 using a pair of similar excitation transducers which are opposidely energized.
Claim 7
Dependent Claim
17 words
The method of claim 5 wherein the excitation transducers are positioned vertically with respect to a formation.
Claim 8
Dependent Claim
14 words
The method of claim 6 wherein measuring transducers are located between the excitation transducers.
Claim 9
Dependent Claim
28 words
The method of claim 7 wherein said excitation and measuring transducers are brought into contact with a side wall of the borehole for transmission into the adjacent formation.
Claim 10
Dependent Claim
106 words
Formation permeability logging apparatus comprising: a sonde adapted to be lowered into a well to be tested; excitation transducer means carried on said sonde and including at least two transducers which are driven with signals of opposite polarities for forming an acoustic wavefront impinging on a formation to be tested to create a localized fluid flow in the formation; means for transmitting a sonic wave through the localized fluid flow in the formation; and, means for measuring variations in transmission time of the sonic wave as a result of passage through the localized fluid flow which variations are a function of the permeability of the formation.
Claim 11
Dependent Claim
106 words
Formation permeability logging apparatus comprising: a sonde adapted to be lowered into a well to be tested; excitation transducer means carried on said sonde and including at least two transducers which are driven with signals of opposite polarities for forming an acoustic wavefront impinging on a formation to be tested to create a localized fluid flow in the formation; means for transmitting a sonic wave through the localized fluid flow in the formation; and, means for measuring variations in transmission time of the sonic wave as a result of passage through the localized fluid flow which variations are a function of the permeability of the formation.
Claim 12
Dependent Claim
28 words
The apparatus of claim 9 wherein said transmitting means cooperates with a receiving means and sonic signals are transmitted therebetween of a specified frequency and at timed intervals.
Claim 13
Dependent Claim
29 words
The apparatus of claim 9 wherein said means for measuring includes means for measuring transmission time variations of sonic wave traveling in opposide directions through the localized fluid flow.
References Cited (Backward Citations)
US3363719A
Cited
US3622969A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-08-18 | 1979-02-17 | 1979-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-18 | 1983-02-17 | 1983-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-18 | 1987-02-17 | 1987-08-19 | $7700.00 | Window Closed / Lapsed |