US3896413A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Permeability logging method using apparatus comprising current electrodes between electromagnets, current electrode on the surface and acoustic listening devices to detect pressure related noise
Assignee: Texaco Inc
•
Filing: 1974-01-28
•
Granted: 1975-07-22
•
Expires: 1994-01-28
Abstract
Abstract A method and apparatus which describe a technique for measuring formation porosity in a formation adjacent to a wellbore. A sonde is lowered to a desired depth in a well adjacent to a formation of interest. The sonde includes magentic poles which form lines of flux in the formation. Intermediate of the magnetic poles is a current electrode. A return path for the current electrode is completed preferably at the surface. The current flow path in the formation from the current electrode is approximately perpendicular to the magnetic flux lines. The two fields impinge on fluids located in the interstices of the formation, creating localized pressure which is relieved by fluid flow in the formation. The fluid flow is accompanied by noise created by the fluid interacting with the formation which defines many serpentine and erratic flow paths. The noise is heard by a wide band acoustic listening device. The noise is related to a permeability of the formation.
Inventors
- 👤 Donald J Dowling
- 👤 John F Boyd
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:07
CPC Classifications
G; G01; G01V; G01V11/00; G01V3/00; G01V3/18; G01V3/26; G01V3/265
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
73 words
A method for measuring permeability of a formation adjacent to a borehole comprising the steps of: forming essentially stable constant magnetic flux lines in a localized region in a formation of interest; forming direct electric current flow paths in the same localized region of the formation at substantially riGht angles to said magnetic flux lines; and listening to the noise of fluid movement in the formation to obtain an indication of formation permeability.
Claim 2
Independent Claim
73 words
A method for measuring permeability of a formation adjacent to a borehole comprising the steps of: forming essentially stable constant magnetic flux lines in a localized region in a formation of interest; forming direct electric current flow paths in the same localized region of the formation at substantially riGht angles to said magnetic flux lines; and listening to the noise of fluid movement in the formation to obtain an indication of formation permeability.
Claim 3
Dependent Claim
22 words
The method of claim 1 wherein a magnet having a pair of spaced magnetic poles is placed substantially against the borehole wall.
Claim 4
Dependent Claim
39 words
The method of claim 1 wherein a magnet having a pair of spaced poles is positioned adjacent to the formation and a direct current injection electrode is positioned between the poles to form the direct electric current flow paths.
Claim 5
Dependent Claim
18 words
The method of claim 1 wherein said listening step occurs simultaneously with formation of the lines and paths.
Claim 6
Dependent Claim
12 words
The method of claim 4 wherein the noise is amplified and filtered.
Claim 7
Dependent Claim
12 words
The method of claim 5 wherein the noise is recorded after amplification.
Claim 8
Dependent Claim
23 words
The method of claim 1 wherein a ground electrode is placed elsewhere and an injection electrode forms the direct electric current flow paths.
Claim 9
Dependent Claim
27 words
The method of claim 1 wherein the magnetic flux lines and direct electric current flow paths are formed prior to listening for the noise of fluid movement.
Claim 10
Independent Claim
100 words
An apparatus for measuring permeability of a formation adjacent to a borehole, comprising: a tool adapted to be lowered into a well bore to a selected depth; means carried thereon for forming substantially constant magnetic flux lines in a localized region in a formation adjacent to the well bore; means carried on said tool for forming a direct electric current flow path in the same localized region of the formation; listening means for listening to the noise of fluid movement in the formation of interest; and, indicating means connected to said listening means for providing an indication of formation permeability.
Claim 11
Independent Claim
100 words
An apparatus for measuring permeability of a formation adjacent to a borehole, comprising: a tool adapted to be lowered into a well bore to a selected depth; means carried thereon for forming substantially constant magnetic flux lines in a localized region in a formation adjacent to the well bore; means carried on said tool for forming a direct electric current flow path in the same localized region of the formation; listening means for listening to the noise of fluid movement in the formation of interest; and, indicating means connected to said listening means for providing an indication of formation permeability.
Claim 12
Dependent Claim
19 words
The apparatus of claim 9 including means for lowering the tool to a selected depth in a well bore.
Claim 13
Dependent Claim
28 words
The apparatus of claim 9 including a return ground electrode adapted to complete a circuit with said means for forming a direct electric current flow in the formation.
Claim 14
Dependent Claim
26 words
The apparatus of claim 9 wherein said tool carried magnetic means having a pair of spaced magnetic poles adapted to be placed against the borehole wall.
Claim 15
Dependent Claim
22 words
The apparatus of claim 11 wherein said tool carries a direct current injection electrode positioned between the poles of a magnet means.
Claim 16
Dependent Claim
18 words
The apparatus of claim 9 including a filter means connected between said listening means and said indicating 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) | 1978-07-21 | 1979-01-20 | 1979-07-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-21 | 1983-01-20 | 1983-07-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-21 | 1987-01-20 | 1987-07-22 | $7700.00 | Window Closed / Lapsed |